Alligator Rivers Region Technical Committee Meeting 28

Minutes

17 – 18 April 2012

ARRTC28 Meeting Summary Page 2 of 25

Alligator Rivers Region Technical Committee Meeting 28

Agenda Tuesday 17 April 2012 1 Preliminary Session (Chair)

1.1 Welcome and Introductions 1.1.1 New members 1.1.2 Appointment of new Chairperson

1.2 Apologies 1.3 Correspondence 1.4 Conflict of Interest Declarations 1.5 Governance

2 ARRTC27 Outcomes (Chair) 2.1 ARRTC27 - Summary Record 2.2 ARRTC27 - Business Arising

3 Stakeholder Reports 3.1 Department of Resources (Mr Ball) 3.2 Northern Land Council (Mr Thompson) 3.3 Parks Operations and Tourism Branch (South Alligator Valley) (Ms Morgan) 3.4 Supervising Scientist (including Monitoring) (Dr Jones) 3.5 Environment NGOs (Dr Mudd) 3.6 Uranium Equities Ltd (Nabarlek) (Ms Tayler))

4 Science underpinning regulatory decisions (Mr Ball) 5 Research Reports

5.1 Supervising Scientist Division 5.1.1 Proposed eriss research program 2012-13 (Dr Jones, eriss)

5.2 Energy Resources of Australia Ltd 5.2.1 ERA operations and ITWC update (Dr Sinclair)

6. KKN review and status reporting (ERA/eriss) 6.1 KKN status summary

Wednesday 18 April 2012

6. KKN review and status reporting (cont.) 7 Other Business

7.1 SSD publications since ARRTC27 7.2 ERA publications since ARRTC27

8 Next Meeting

ARRTC28 Meeting Summary Page 3 of 25

ARRTC28 - Attendance Members Dr Simon Barry Independent Scientific Member and Chairperson Dr Jenny Stauber Independent Scientific Member Prof Paul Boon Independent Scientific Member Ms Jane Coram Independent Scientific Member Prof David Mulligan Independent Scientific Member Mr Andrew Johnston Independent Scientific Member Dr Gavin Mudd Environment NGO stakeholder member Dr Greg Sinclair Energy Resources of Australia Ltd (ERA) Mr Russell Ball NT Department of Resources (DoR) Ms Anna Morgan Parks Australia Division Apologies Prof Colin Woodroffe Independent Scientific Member Dr Howard Smith Northern Land Council (NLC) Mr Alan Hughes Supervising Scientist Ms Melissa Taylor Uranium Equities Limited (UEL) Presenters/Observers Mr Geoff Kyle Gundjeihmi Aboriginal Corporation (GAC) Mr Peter Waggitt NT Department of Resources (DoR) Ms Shelly Iles Energy Resources of Australia Ltd (ERA) Dr Ping Lu Energy Resources of Australia Ltd (ERA) Dr Peter Anderson Energy Resources of Australia Ltd (ERA) Ms Sharon Paulka Energy Resources of Australia Ltd (ERA) Mr Nathaniel Toll Energy Resources of Australia Ltd (ERA) Ms Nicole Jacobsen Energy Resources of Australia Ltd (ERA) Ms Cherie Gellert Energy Resources of Australia Ltd (ERA) Dr Anja Zimmermann Energy Resources of Australia Ltd (ERA) Dr Jeff Tsang Energy Resources of Australia Ltd (ERA) Mr Reid Miller Energy Resources of Australia Ltd (ERA) Dr Phillipe Puig Energy Resources of Australia Ltd (ERA) Mr Peter Poole Energy Resources of Australia Ltd (ERA) Mr Adam Thompson Northern Land Council (NLC) Dr David Jones Environmental Research Institute of the Supervising Scientist Dr Andreas Bollhöfer Environmental Research Institute of the Supervising Scientist Dr Chris Humphrey Environmental Research Institute of the Supervising Scientist Dr Renée Bartolo Environmental Research Institute of the Supervising Scientist Dr Mike Saynor Environmental Research Institute of the Supervising Scientist Dr Wayne Erskine Environmental Research Institute of the Supervising Scientist Dr Rick van Dam Environmental Research Institute of the Supervising Scientist Mr John Lowry Environmental Research Institute of the Supervising Scientist Other SSD staff SECRETARIAT Mr Scott Parker Office of the Supervising Scientist Ms Shannon Traut Office of the Supervising Scientist

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1 PRELIMINARY SESSION - CHAIR 1.1 WELCOME AND INTRODUCTIONS The Chair (Dr Barry) welcomed members and observers to the 28th meeting of the Alligator Rivers Region Technical Committee. Members congratulated Dr Barry on his appointment by Minister Burke as the ARRTC Chairperson. Dr Barry also noted the recent appointment of Ms Melissa Taylor as the Uranium Equities Limited (UEL) stakeholder member.

1.2 APOLOGIES Dr Barry noted the following apologies and observers. Apologies Prof Colin Woodroffe 17-18 April 2012 Dr Howard Smith 17-18 April 2012 Mr Alan Hughes 17-18 April 2012 Ms Melissa Taylor 17-18 April 2012 Dr Greg Sinclair 0830 – 1300, 17 April 2012 Observers Mr Geoff Kyle GAC (permanent observer)

1.3 CORRESPONDENCE Dr Barry noted the following correspondence. Outgoing - Letter to Minister Burke – ARRTC27 outcomes (17 February 2012) Incoming - Letter from Minister Burke – ARRTC27 outcomes (15 March 2012)

1.4 CONFLICT OF INTEREST DECLARATIONS Dr Barry called for conflict of interest declarations. Ms Coram advised that as an employee of Geoscience Australia she is periodically requested to provide technical advice on groundwater issues at Ranger to a number of Australian Government departments and would advise the Chair should any potential conflict of interest issues arise. Dr Stauber advised that CSIRO is currently engaged by Energy Resources of Australia Ltd on sediment and Pit#1 rehabilitation related projects.

1.5 GOVERNANCE Mr Parker advised that the draft ARRTC Terms of Appointment document has not yet been finalised pending advice from the Governance area of his Department. He advised the draft would be circulated to members once finalised. Mr Parker noted that Dr Sinclair also has some matters he would like to raise under this agenda item and it was agreed to discuss this item further when Dr Sinclair is present (see Section 1.5 on page 23).

2 ARRTC27 OUTCOMES 2.1 ARRTC27 - SUMMARY RECORD Dr Stauber noted there are some words missing on Page 201

ARRTC28-1: ARRTC approved the ARRTC27 meeting summary as tabled with one minor amendment (p.20).

of the draft ARRTC27 Meeting Summary. The draft Meeting Summary was approved with this minor amendment.

It was noted the ARRTC meeting summaries to date have provided a detailed record of the business of each meeting but questions were raised as to whether this level of detail is actually required. One option proposed was to consider moving towards an executive summary approach. However, it was also noted by several members that the current level of detail in ARRTC meeting summaries is highly valued by stakeholders and fulfils ARRTC’s statutory role in maintaining transparency. It was noted that detailed meeting summaries also provide a valuable reference for ARRTC members who are not able to attend meetings, and for new members of the committee. ARRTC agreed that future meeting summaries should be more concise and not include individual member attributions. It was agreed it is important the meeting summary record the key issues discussed and any outcomes.

ARRTC28-2: ARRTC agreed that the meeting summary for this and future meetings should be more concise and should aim to capture the key discussion points and outcomes of the meeting without attributing individual members. ARRTC28-3: ARRTC agreed the draft actions should be circulated to members within 4 weeks of each meeting, and the draft minutes circulated within 8 weeks.

2.2 ARRTC27 - BUSINESS ARISING Action Responsibility Status ARRTC27-1: ARRTC noted the need to review and update current governance Secretariat Addressed

1 “...possess knowledge of how the site looked pre mining.”

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arrangements for the Committee and agreed to consider proposed changes and associated documentation out-of-session.

under Agenda item 7. Other Business.

ARRTC27-2: The ARRTC26 minutes were approved without amendment. Complete ARRTC27-3: ARRTC agreed:

• to have a standing agenda item for reviewing and updating KKNs at each meeting (towards end);

• that research reports would include statements on how the work has addressed the relevant KKNs, the extent of completeness and identifying any other further knowledge gaps, and

• to have an annual detailed review of the status of the KKNs at the second meeting of each year.

Secretariat; eriss; ERA

Complete

ARRTC27-4: ARRTC requested Ms Paulka to seek agreement from UEL to provide closure criteria and hydrogeological review reports to Prof Mulligan and Gavin Mudd (and other ARRTC members?).

Ms Paulka UEL to address Carryover

ARRTC27-5: ARRTC agreed that UEL be invited to submit a proposal to amend KKN 4.2 and that ARRTC then consider based on the evidence that has been provided to support this.

Ms Paulka UEL to address Carry over

ARRTC27-6: ARRTC requested that Mr Balding provide a copy of the monitoring data report on the SAV project to ARRTC members out-of-session.

Mr Balding Complete

ARRTC27-7: ARRTC agreed that for future meetings the MTC minutes would be included as an appendix in the DoR report and that DoR would provide a summary under Agenda Item 5 of the science that underpinned regulatory decisions during the reporting period.

Mr Ball Complete

ARRTC27-8: ARRTC commended SSD on the quality of the work to date on determining pre-mining radiological conditions at Ranger

Complete

ARRTC27-9: ARRTC commended SSD on the ongoing high quality of its scientific research and the presentations to this meeting.

Complete

ARRTC27-10: ARRTC agreed that the KKNs (and projects under each KKN) should be prioritised based on current mine closure and rehabilitation timeframes

Secretariat; members

Complete

ARRTC27-11: ARRTC requested that ERA present to next meeting an update on the current closure schedule components, and the relative priority and status of research addressing these, under each relevant KKN.

Dr Sinclair Complete

ARRTC27-12: Prof David Mulligan agreed to assume acting chair as Dr Barry had to leave meeting to attend to an urgent household matter

Complete

ARRTC27-13: ERA to provide copy of Gulungul catchment report to ARRTC members Dr Sinclair Check then Complete

ARRTC27-14: ERA to provide summary report on LAA rehabilitation to Mr Johnston when released

Dr Sinclair Complete

ARRTC27-15: ARRTC commended ERA staff on the breadth and quality of their presentations to the meeting.

Complete

ARRTC27-16: ARRTC noted Dr Barry will draft a letter to Minister Burke communicating the outcomes from ARRTC27 and this will be circulated to members out-of-session for comment.

Dr Barry Complete

ARRTC27-17: ARRTC agreed to undertake a field trip to Ranger immediately prior to ARRTC29 in October 2012 subject to ERA operational requirements

Secretariat Add to ARRTC29 agenda

ARRTC27-18: ARRTC agreed that the process for reviewing and updating KKNs would be resolved out-of-session.

Secretariat; members

Complete

ARRTC27-19: ARRTC agreed the agenda for the next ARRTC meeting would be structured on the current KKNs and that information should provided in tabular form to enable members to record their comments, changes to and/or any new KKNs

Secretariat Complete

ARRTC27-20: ARRTC agreed the next meeting would be held in April 2012 and that the Secretariat would circulate possible dates.

Secretariat Complete

3 STAKEHOLDER REPORTS 3.1 NT DEPARTMENT OF RESOURCES (MR BALL) Mr Ball provided an update on DoR regulatory activities during the reporting period. Key points noted by ARRTC and raised in discussion are outlined below.

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The MTC is currently considering the Maximum Operating Level (MOL) to be applied to the Tailing Storage Facility (TSF) at Ranger. Discussions between relevant stakeholders are continuing, taking into account current water management contingencies at Ranger and the largest Bureau of Meteorology (BoM) calculated Probable Maximum Precipitation (PMP) for the site. ARRTC discussed the basis of choosing a PMP duration, interpretation of Australian National Committee on Large Dams (ANCOLD) guidelines and the distribution PMP likelihood across a season. ARRTC recommended that the probability of occurrence and distribution of likely frequencies of rainfall should be considered. DoR is currently looking at undertaking an audit to ensure contingency water management arrangements are appropriate, including viewing of pumping transfer capacity tests from the TSF to Pit 3, to demonstrate capability of managing the largest PMP event (120 hour) calculated by BoM. Further advice on the MOL will be provided to next meeting. ARRTC noted a list of key applications to the MTC that were granted regulatory approval during the reporting period, as well as a listing of the relevant scientific and technical information which informed these decisions. The role and extent of ARRTC’s involvement in relation to the regulatory process was discussed. It was agreed that ARRTC’ has an ongoing interest (and statutory responsibility) in ensuring that the science used to inform the regulatory decision making process is of appropriate quality. ARRTC28-4: ARRTC requested that DoR provide the outcomes of ongoing work on the new Maximum Operating Level to members out-of-session. ARRTC28-5: ARRTC requested that DoR and ERA circulate their respective reports from the Bureau of Meteorology on Probable Maximum Precipitation.

3.2 NORTHERN LAND COUNCIL (MR THOMPSON) Nothing to report.

3.3 PARKS OPERATIONS AND TOURISM BRANCH (MS MORGAN) Ms Morgan provided an update report on the South Alligator Valley rehabilitation project. Key points noted by ARRTC and raised in discussion are outlined below. ARRTC expressed concern that the proposed monitoring duration of 4 years may be insufficient in terms of detecting possible groundwater impacts over the longer term and requested further information on the groundwater monitoring strategy being proposed by O’Kanes Pty Ltd to assess whether it is appropriate and adequate. It was recommended that potential risks to vegetation success due to termite activity associated with the proposed use of tree debris for surface erosion protection on the containment be assessed. ARRTC28-6: ARRTC requested that Parks Australia provide a copy of the O’Kanes Pty Ltd proposal (if possible) and further details on the groundwater monitoring program being put in place for the SAV rehabilitation project.

3.4 SUPERVISING SCIENTIST DIVISION (INCLUDING MONITORING) (DR JONES) Dr Jones provided an update on the outcomes of SSD research and monitoring activities over the reporting period. Key points noted by ARRTC and raised in discussion are outlined below. Monitoring - The current wet season has been average and there are no significant issues to report in terms of the results from the various water quality and in situ biological monitoring programs. It was noted that committee members would like to see the results of SSD monitoring activities that are routinely presented at ARRAC meetings, as ARRTC members do not get to see these. ARRTC28- 7: ARRTC requested that the Secretariat circulate the SSD report to ARRAC37 to members, and that SSD ARRAC reports be circulated with the draft ARRTC minutes for future meetings. Operational Issues - ARRTC noted that following the TSF raise to 58mRL, the issue of the MOL is being reviewed by the MTC. The interim decision by the MTC to have a wet season MOL of 56m and a dry season MOL of 57m was made pending a detailed report from BOM, which has now been received by DoR. SSD has conducted ecotox work on the distillate product from a pilot plant as part of the assessment of the proposed brine concentrator for process water treatment. The product water from the operating full scale plant will also be tested to confirm that water is of suitable quality for discharge. The brine concentrator is expected to be operational by July 2013. ARRTC noted that the application for the exploration decline stated that any ore grade material recovered from the exploration decline will be separately stockpiled and not processed. Groundwater modelling - ERA is looking at using process water as a tracer for calibrating reactive transport groundwater modelling between Pit 1 and Corridor Creek using real field data, and is keen to ensure that any risks are minimised. A preliminary test using sodium bromide (a conservative tracer) revealed a problem with capture of the tracer plume. Work is being undertaken to optimise the arrangement of the injection and recovery pumping to ensure tracer capture effectiveness before considering using process water as a tracer which would be subject to MTC approval. It was noted that there are multiple uncertainties in the field which need to be accounted for, especially when developing and parameterising the groundwater contamination model and the tests are designed to address these uncertainties. Mg Pulse trigger value - SSD has completed ecotox work on Mg pulse exposure and should soon be in a position to develop a Mg pulse trigger framework for consideration by the MTC prior to the start of the next wet season. SSD has also been identifying

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implications for SSD monitoring and research priorities associated with the evolving ERA closure planning and knowledge requirements.

3.5 ENVIRONMENT NGOS (DR MUDD)

Dr Mudd advised that environment NGOs have ongoing concerns about future developments at the Ranger mine, despite the recent increased momentum in closure planning. The key issue will be what happens once the exploration decline has been completed and the next decision point is reached regarding underground mining. Water management issues also continue to be of concern.

3.6 URANIUM EQUITIES LTD (NABARLEK) (MS TAYLOR) Nothing to report.

4 SCIENCE UNDERPINNING REGULATORY DECISIONS (MR BALL) ARRTC noted this item was addressed as part of the DoR update under Agenda Item 3.

5 RESEARCH ACTIVITIES 5.1 SUPERVISING SCIENTIST DIVISION 5.1.1 SSD PROPOSED 2012-13 RESEARCH PROGRAM (DR JONES) Dr Jones provided an update on the proposed SSD research program for 2012-13. Key points noted by ARRTC and raised in discussion are outlined below. Monitoring – The current wet season has been average compared to previous years with 1524 mm of rainfall to 13 April 2012 (average = 1560 mm). All monitoring equipment has operated effectively. It was noted that rainfall distribution through the wet season has direct implications for water management strategies in terms of deciding whether to use average or higher than average rainfall event magnitudes. KKN review – The current KKNs have been jointly reviewed by ERA and SSD taking account of the revised closure timelines proposed by ERA. A number of tradeoffs may be required in order to better align research outputs to operational and closure related timeframes. Statutory operational-phase monitoring activities will provide data that feeds directly into defining aquatic-related closure criteria. Budget implications – ARRTC noted that SSD’s 2012-13 budget has been reduced by approximately 8%, affecting recruitment, operational, and consulting budgets. This will significantly reduce SSD’s capacity to engage external consultants and will have direct implications for the eriss research program unless supplementary funding is provided. SSD has taken this into account in planning and prioritising research projects to focus in the shorter term on the highest priority knowledge requirements. Better use of shared resources will be required where possible.

ERISS 2012-13 RESEARCH PROPOSALS Ecotoxicology (KKN 1.2.4) – Key projects for 2012-13 include deriving trigger values for ammonia and manganese (brine concentrator distillate assessment) and uranium in sediments (natural billabongs closure criteria and sentinel polishing wetlands post mining). Projects to assess the effects of suspended sediments on aquatic biota will be delayed owing to limits on resources. It is unclear if sediment U toxicity data produced from the proposed 2012-13 wet season field deployment will be able to be fully analysed to provide a trigger value recommendation by Q4 2013. SSD’s current recruitment freeze may affect availability of staff resources for this work. The option of sending some spiked sediment samples to CSIRO in Adelaide for lab-based sediment toxicity testing using established species/methods may be worth re-visiting. Although species type is an issue (i.e. use of non-tropical species), this is one means of obtaining some data sooner to produce an indicative trigger value for U. This option will be re-considered once the results from reanalysis of genomic data from the 10/11 pilot deployment are available and interpreted in the context of designing the program for the full scale 2012-13 wet season experiment. Monitoring (KKN 1.3.1) – No significant changes are proposed to SSD’s integrated stream monitoring program. SSD will be taking over responsibility from NRETAS for managing the gauging station 009 this dry season. Dr Alana McKay will be working with Ms Kate Turner on deriving solute and sediment loads and budgets for Magela and Gulungul Creeks using the continuous monitoring and other data acquired over the last six years. Near surface interflow is the key process driving the lateral transmission of salts in the shallow soil horizon associated with the land application areas adjacent to Magela Creek. The contributions of groundwater from the rehabilitated site will need to be specifically addressed by the long term groundwater modelling being done as part of the closure planning process. It was noted that groundwater will become more important over the longer term as the current cones of depression around the Pits recover. ARRTC asked whether biogenomic studies had been considered as part of SSD’s biological monitoring program and it was noted that further R&D was required before the technique could be applied routinely in SSD’s programs. ARRTC suggested groundwater is a fundamental component of solute budgeting and should have increased focus. ERA carried out a review in 2011 into the causes of the spikes being observed in some bores which showed that some parameters being monitored don’t provide very useful information. ERA is developing the groundwater database to characterise aquifers and to prioritise research effort. ERA is monitoring over 200 bores on the site and will recommend to MTC what further groundwater monitoring is required.

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Surface water transport and monitoring Mussel studies – ARRTC noted this work is important in terms of providing assurance to stakeholders. Proposed work for 2012-13 includes developing an efficient methodology for Polonium 210 using liquid scintillation counting. REHABILITATION KKN 2.X.X Landform design and evolution (KKN 2.2.1 & 2.2.4) Trial landform – proposed work for 2012-13 includes continuing measurements for Plots 1 and 2 (rainfall, runoff, water quality, radionuclides, suspended sediment and bedload) to inform long-term predictive geomorphic modelling of proposed landform designs, assessing effects of development of vegetation cover on erosion rates and estimates of post closure export loads. SSD is currently looking at how the trial landform is evolving through time in terms of erosion potential and solute loads. While it was initially thought that the waste rock/laterite plots would hold water better, it is now known that in practice this treatment promotes development of a surface seal and results in surface ponding. ERA is still considering whether there will be a laterite layer placed deeper down in the profile in the final constructed landform. This could mimic the perched water table condition that occurs during the wet season in the regional landscape. Data collection is ongoing from the trial landform. Future work by SSD will concentrate on waste rock plots only (Plots 1 and 2) given that waste rock is the preferred cover type at this stage. Modelling stability of Pit 1 landform and Ranger trial landform – A draft Digital Elevation Model (DEM) has been received from ERA for the latest version of the proposed final landform. This is being assessed for suitability prior to the start of Phase 1 (static datum) CAESAR geomorphic evolution modelling. Phase 1 will involve modelling the endpoints of consolidation of the landform incorporating the initial (Pit 1 backfilled with a domed surcharge) and post-consolidation elevation data for Pit 1. Phase 2 modelling will use an enhanced version of CAESAR which will incorporate dynamic consolidation to model the changes in the erodability of the consolidating Pit #1 landform through time. This enhanced model is currently being developed by Prof Tom Coulthard from the University of Hull. Prof Coulthard is the author of the CAESAR model and will be working with SSD for three weeks in June 2012 to implement and test the model using consolidation rate data supplied by ERA. ARRTC noted the likely consequences of the initially domed landform may include higher erosion risks over the first decade or so, depending on the nature of the material. ERA advised that an important design consideration for the final landform involved minimising the need for reworking and moving material around the site. ARRTC noted the initial focus is on the Pit#1 catchment and the first phase of modelling will be using a static datum, and then look at incorporating consolidation. The modelling work is computationally complicated and that is why Prof Tom Coulthard’s assistance has been sought. ARRTC noted that the modelling is basically being used for design optimisation purposes at this stage as no formal agreement has been reached with the Mirrar on what the final landform will look like. However, it was noted the currently proposed design has taken into account some of the considerations already discussed with the Mirrar. This consultation will continue through the Closure Working Group. Modelling stability of landform over longer term (10,000 yrs) – This work involves inputting briefer periods of extreme-event scenarios into CAESAR with the outputs being fed into SIBERA to account for the balance of 10,000 years. There are a number of slackwater deposits in the East Alligator catchment where materials were deposited during historical extreme flood events. Both the magnitude and frequency of these events provide an upper boundary condition for the types of extreme events that could be input into the CAESAR model. It was noted that possible effects of climate change also need to be considered in the modelling. However, it remains to be defined how climate change effects should implicitly be considered as part of the long range scenario for the ARR, over and above incorporating the data from historical extreme events. Water and sediment closure criteria (KKN 2.2.2) – A strategic framework for deriving closure criteria is required which takes account of spatial and temporal aspects, and the role of different derivation methods (baseline, field biological effects, ecotoxicity). Rehabilitated mine sites typically display an initially higher export of solutes and suspended sediment, which decrease as the source terms deplete over time. The type of reference condition to be considered for establishing closure criteria needs to be very carefully considered in the context of the protection objective. For example, setting a downstream water quality condition similar to the upstream reference site is unrealistic given that historically the downstream site would likely have been impacted by weathering of the surface–exposed orebodies. Also need to consider differences between the biological evidence found from effects of exposure gradients in the field, and inferences that may be made from direct measurements of toxicity in the laboratory. Proposed work for 2012-13 includes determining baseline reference condition from existing data, continuing work on field biological effects (billabong water quality and sediments) and ecotoxicity studies (Mg, U and DOC relations, suspended sediments, Mn and ammonia in waters and U in sediments). ARRTC noted the importance of looking at ingestion pathways and the role of DOC amelioration for U toxicity. Radiological Characterisation of final landform (KKN 2.2.5) – work proposed for 2012-13 includes writing up the pre-mining assessment (Anomaly 2) work with inclusion of pre-mining uptake pathway analysis and focusing on radon exhalation work on trial landform. Ecosystem establishment (KKN 2.5.2 & 2.5.3) – work proposed for 2012-13 includes using digitised, ortho-rectified aerial photographs to establish pre-mining vegetation condition and behaviour at Ranger, measuring medium term (40-110 years) soil erosion rates in analogue areas using 137Cs and 210Pbex and analysis of a 10yr dataset to define baseline geomorphic characteristics of the Gulungul Creek catchment. SSD has acquired from Parks Australia a good premining photographic record back to the 1950s including colour and infra-red. ARRTC noted that a degree of caution is required when using photographic

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records to look at landscape evolution through time to ensure what is depicted is natural and not a modified landscape. SSD will use a landform ecology approach looking at key disturbances. The vegetation analogue areas will be used to establish species type and optimum vegetation densities for each type of physical environment present of the final landform. New research looking at aquatic plant community dynamics in existing mine ponds and treatment wetlands and in natural ARR lowland billabongs is proposed to determine environmental flow requirements for the establishment of effective sentinel polishing wetlands and restored waterbodies (e.g. Djalkmarra billabong) in the rehabilitated mine landscape. Radiation exposure pathways (KKN 2.5.4) – proposed work for 2012-13 includes further development of the Bioaccumulation of Radioactive Uranium-series Constituents from the Environment (BRUCE) database and estimation of radiation dose for non-human biota. Ecological risk assessment (KKN 2.7.1 & 5.1.1) – This work has been a long running over-arching research question and involves two components: (1) ecological risk assessment of the rehabilitation and post rehabilitation phases and (2) landscape scale ecological risk assessment for the Magela catchment. The future development of this research area will be a joint process involving ERA, GAC, NLC and SSD, and will incorporate Traditional Ecological Knowledge (TEK). ERA will be looking to NLC and GAC for assistance with incorporating TEK into the risk assessments. ARRTC noted Dr Howard Smith’s extensive knowledge and expertise in this area. It was noted that TO input will be required in relation to the final landform shape and design and that this should occur as soon as possible in the planning process. Both ecological and cultural aspects will need to be addressed as part of the decommissioning and rehabilitation risk assessment process. ARRTC noted that information has been provided by ERA to TOs and that consultations are already underway. ERA advised that the integrated closure process is based on current agreements in terms of timeframes, and that pilot rehabilitation projects are in the process of being designed in collaboration with GAC and NLC to test the best means of incorporating TO cultural knowledge. Monitoring post rehabilitation – proposed work for 2012-13 includes developing and trialling of remote sensing technologies (including evaluation of potential of UAV technology) for vegetation monitoring, and spectral and chemical characterisation of archived samples of suspended sediments and soils to fingerprint sediment provenance. This work is linked to offsite monitoring and broader catchment scale monitoring. ARRTC noted the recent developments in UAV technologies and associated benefits for research and a number of ARRTC members expressed interest in this work, noting the potential for future collaboration. It was noted that there was risk to the full scope of this work progressing in 2012/13 as a result of cuts to SSD’s operating budget. Direct costs can potentially be reduced by cost sharing with other agencies and research groups (e.g. Parks and the Northern NERP Hub). Monitoring post rehabilitation – ARRTC noted that aspects of SSD’s stream/billabong research and monitoring are transferable to monitoring the aquatic environment after rehabilitation, in addition to being used to develop water quality closure criteria. Landform evolution monitoring will be achieved through a combination of joint ERA-SSD terrestrial analogue vegetation plots, and on-ground and remote sensing monitoring approaches. Knowledge management projects - Work will continue in 2012-13 on knowledge management projects including the Envirosys database (for point source chemical, radiological and biological data) and a new electronic document records management system (EDRMS) base on the Microsoft SharePoint platform. It was noted that some discussions have occurred looking at possible linkages between the SSD point source database and the ERA groundwater database and some data from the eriss groundwater database have already been provided to ERA. In closing this segment of the meeting, ARRTC noted SSD’s budget constraints for 2012/13 and associated uncertainties for the research program.

ARRTC28-8: ARRTC noted the implications of current budget constraints in terms of the prioritisation and possible deferral of some SSD research activities for 2012-13. ARRTC28-9: ARRTC commended SSD staff on the quality of their 2012-13 Research Report and technical presentations to this meeting.

5.2 ENERGY RESOURCES OF AUSTRALIA LTD 5.2.1 ERA OPERATIONS AND RESEARCH SUMMARY 2011 (DR SINCLAIR) Dr Sinclair provided a presentation on ERA operations during the reporting period. Key points noted by ARRTC and raised in discussion are outlined below. Safety Performance - despite challenging conditions in 2011, ERA maintained its strong focus on safety, achieving a world class two million hours without a Lost Time Injury (LTI) and an All Injury Frequency Rate (AIFR) of 0.57. ERA achieved 336 consecutive days without a LTI - a company record. There was one LTI and five medical treatment injuries. All staff made a full recovery. Business Summary – ERA’s Annual Report was released at the company’s AGM last week. Due to the large wet season experienced, ore processing was suspended for five months as a proactive measure to manage the process water inventory without risk to the environment. This resulted in a substantial drop in annual production and profit. During this period, extensive maintenance was carried out which permitted production rates to reach record levels once processing recommenced. Production for 2011 was 2,641 tonnes of uranium oxide. All sales commitments were met through inventory management, loans and purchase of material on the spot market. A total of 5.5GL of pond water was treated (including 3.5GL of water from Pit#3). An Entitlement Offer was completed raising approximately $500 million to fund key strategic initiatives including the Integrated

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Tailings, Water and Closure study, the Exploration Decline project and associated studies, the brine concentrator plant for process water treatment, and exploration. The rehabilitation provision increased from $315 million (31 December 2010) to $565 million (31 December 2011). ERA expects to approve the Ranger 3 Deeps pre feasibility study in June 2012. Operational performance – Plant and mining activities in 2011 were significantly impacted by the well above average 2010/11 wet season. After the proactive suspension of processing operations was lifted in June, the plant has operated at record levels and significant productivity improvement occurred in the mine. Ranger 3 Deeps exploration decline – This project is a key focus for ERA in 2012. The $120m capital project involves the construction of a box cut and exploration decline. Contractors are onsite and the box cut and portal access tunnel are expected to be completed by October 2012. The exploration program will involve 35,000m of underground drilling plus a further 16,000m of resource drilling which is expected to commence from Q3 2013. The project includes a vent shaft and cross cut into the ore body. ARRTC noted any proposal to proceed with an underground mine will likely trigger relevant government environmental approvals processes. Rainfall – Total rainfall to date this wet season (1523 mm) is slightly above average (approximately 1.5m water has fallen on the site). Western Stockpile seepage interception trench – The trench has intercepted 2076ML during 2011; mainly pond water quality which was treated through the treatment plants. About 1/3 of this volume reports to the brine stream which is stored in the TSF, or in RP2 under certain approved conditions. The construction of the interception trench system has resulted in substantial water quality (EC) improvements in RP1 and Magela Creek. Pit#3 status – Mining in Pit#3 is expected to be completed by Dec 2012/Q1 2013. ERA expects with optimisation, the Pit could go down to RL-250m, if supported by remaining ore levels. Currently there is about 1GL water in the base of the Pit, which needs to be removed and treated to permit mining access to the base of the pit. Once mining is completed the base of the pit can be prepared for tailings deposition. This will involve partial backfill of the base of the pit with rock to produce an underblanket drain to facilitate vertical drainage and consolidation of the deposited tailings. ERA expects to complete mining in Pit#3 by Q1 2013 at the latest. New projects – ERA is looking at 2 new projects: two additional pond water storages and a further 2.5m lift of the TSF. The additional storages are required for pond water storage to replace that which is currently accommodated by Pit#3 during the wet season. The ponds will be lined and hold around ~ 1GL each. It is possible that these ponds may be used for other purposes in the future but that would require a specific application and approval via the MTC process. TSF groundwater monitoring program – A total of 78 new bores were installed and 2 bores refitted to address recommendations from the independent TSF review. Some are equipped for continuous monitoring. This has improved the groundwater monitoring network and provided improved understanding of hydrogeology of the mine site which is important for rehabilitation planning. Brine concentrator – The brine concentrator is a $220m project approved by the ERA board in February 2012. Detailed engineering work and procurement planning is underway. The plant will be located on the old acid plant site. Fabrication of the distillation towers is underway and expected to be delivered to site in November 2012. Wet season transport of large plant components is a potential project risk so ERA is looking to get large plant components in before onset of wet season. It is expected that the plant will be commissioned by Q3 2013 and will initially produce 1.83 GL/yr of distillate. A pilot plant has been trialled at the Rio Tinto Bundoora facilities. SSD did a comprehensive set of ecotox studies using pilot plant permeate supplied by ERA and will do more once the full scale plant is up and running. INTEGRATED TAILINGS WATER AND CLOSURE (ITWC) PFS This is a $23m study comprising two phases: Phase 1- project definition (Dec 2011 – May 2012) and Phase 2 –Engineering design, costing, and project execution scheduling (May 2012-May 2013). The project is currently well into Phase 1. The aim is to develop a fully integrated and fit for purpose process water, tailings and progressive rehabilitation plan to support ERA’s business strategy and ensure adherence to stakeholder expectations and statutory requirements. Key issues include: how to optimise Pit#3 backfill to maximise consolidation (taking into account seepage control and settlement), identifying the best strategies for: placing material into the Pit, reclaiming the TSF, managing the underlying groundwater, closing Pit#1, implementing incremental brine concentrator treatment capacity to reduce the process water inventory to zero, storing the salt from the brine concentrator, achieving site infra-structure synergies (e.g. power and water systems) and demolition/removal of the plant. At this stage, closure has to be completed by 2026 in accordance with the Section 41 Authority. Any decisions regarding an extension to the lease would be subject to outcomes of discussions with stakeholders. There were questions about the possibility of extending mining past 2021 and whether this would this require an extension of the Section 41 Authority or a new Authority. It was also noted that, even if after extensive discussions all stakeholders agree, the process would take some time due to the legal complexity involved. Pit#1 Closure

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Vertical drainage wicks are to be installed from the end of April through to October 2012. This will facilitate consolidation of the tailings mass prior to the start of pit backfilling. Pit#3 tailings and brine/salt disposal options – there are four broad options being considered. Tailings can be dredged and pumped from the TSF, thickened and then deposited in Pit#3 or can be thickened and then filtered, which would result in more initially dewatered (and consolidated) tailings mass. Salt can be either inject as liquid brine into the underblanket layer at the base of Pit#3 or crystallised out and buried in Pit#3. Intimate co-disposal of tailings with the brine probably wasn’t an option due to this increasing the risk of unacceptable groundwater seepage. Based on encouraging early results modelling the process of brine injection into the base of the pit, crystallisation doesn’t appear to add any value. Moreover, the salts would be placed higher up in the profile where they would dissolve and potentially be more available for lateral groundwater transport. ERA will take the salt crystallisation option to the next stage of comparative evaluation but will continue to explore brine injection. At this time it appears that initial filtering of the tailings does not confer a substantive advantage, in the context of time for consolidation, over thickened tailings alone. However, if additional modelling indicates potential for unacceptable consolidation or seepage issues then filtering will need to be reconsidered. All these options are being assessed under the BPT framework. A technical presentation of the modelling results for the Pit backfill was provided under Agenda Item 6. Progress since last meeting – Workshops are being planned to conduct a BPT assessment for the options being considered. ERA noted that it has designed a robust framework to rank the options and the MTC has reviewed the new framework. This framework includes a broader range of considerations than included in the BPT matrix that has been used previously. The conceptual design basis for candidate options are complete and focus on 2026 as being the completion date. Preliminary results on brine injection and thickening tailings are good so ERA is now moving to large scale testing pilot plus tailings profiling and geophysics. Closure Criteria update - The Closure Working Group has reformed and held its first meeting in December 2011. ERA now chairs the Working Group which intends to hold monthly meetings. Themes for closure criteria have been agreed and progress made towards identifying the required technical information. The Closure WG has looked at priorities and all members agreed that water is the first priority, with landform second. A focus group has been formed to look at cultural criteria (may be criteria or just a framework). ERA held a joint workshop with GAC and NLC looking at integration of TO knowledge into closure design for the LAA, Jabiluka pond, and rehabilitation tracks on the Ranger lease. These smaller projects are considered to be pilots for optimising the incorporation of traditional knowledge into the design and rehabilitation of the final landform and Ranger. ERA will report the outcomes of this process to the Closure WG. Key Knowledge Needs and Engineering elements - ERA has been assessing options to place 30m tonne of rock into Pit#3 while allowing for brine injection into the base of the pit. A capital application is currently being prepared. One option being considered is to use remote controlled dozers. By December 2014, the brine concentrator will be substantively drawing down the process water inventory. The brine stream is very salty and acidic (pH 1.5) so investigations on material reactivity and injection strategies, among others, are being conducted to determine how best to dispose of the brine into the storage voids (around 3GL void storage based on 30m t of rock backfilled). ERA initially looked at having injection infrastructure in the pit but this wasn’t practicable so they are now assessing direct injection via bore lines connected to a ring main around the pit perimeter. Questions were raised about the potential effects of acidic brine on the dolomite units in Pit#3. With the low pH involved, there is a possibility of exothermic reactions occurring. ERA informed ARRTC that it has taken this into account along with possible gas (CO2) production and heat generation, and also commented that secondary mineralisation (formation of gypsum) is also being considered in the context of reducing porosity. The feasibility of lining the lower part of Pit#3 was discussed and it was noted this hasn’t been considered to date, because the bottom of Pit#3 already has very low permeability (i.e. very tight rocks). ERA advised that detailed reports addressing this are available and could be provided to members if required. ARRTC noted that ERA has a very good understanding and knowledge of the geology at the base of the Pit. It was noted that ERA will have to transfer 23m tonnes of tailings from the TSF to Pit #3, starting in 2015. This will coincide with deposition of new tailings being produced by the processing operations. The transfer should be completed by 2021 and will be followed by the placement of rock from the adjacent Western stockpile onto the consolidated tailings. ARRTC was informed that the proposed drilling to install the brine injection bores will be steeply angled from within the bund (but with limited depth to avoid intersecting artesian aquifers) and that ERA will submit an application for this to MTC. ERA has defined the aquifers in terms of porosity and fracture flow, and also looked at some conductivity conservation scenarios. Seepage occurs through the wall of Pit#3 from RP2 due to the presence of a transmissive dolomite unit located between these two features. These factors are being considered in the solute transport modelling being conducted to assess the backfill strategies. Tailings Reclaim & Transfer to Pit 3 – Dredge - In relation to the dredge circuit, the slurry feed reporting to Pit3 will be variable and therefore difficult to predict. Studies and pilot trials are underway to refine this. It was noted pH is also important as it could affect the performance of the tailings thickener. It was noted that there is a potential risk of oxidation of reduced tailings from depth that contain secondary sulfide minerals (formed via sulfate reduction). ERA noted that based on prior experience in Pit 1 that intact core samples can be obtained from depth in wet tailings. ERA is therefore planning to do drilling and coring to determine the variability of tailings physical properties and pH through the tailings

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mass in the TSF. The TSF profiling work will start in May 2012. Concurrently there will be a large scale pilot test of thickener technology. It is currently planned to commission the tailings reclaim dredge by late 2014 and commence operations by January 2015. The high rate thickener will produce a product with 63% water content and flocculants will be added to increase density. It was noted that the dredge requires a minimal level of water to operate and hence there will need to be substantial drawdown of the current depth of the water cover prior to commencing dredging operations. Proposed Pit#3 Backfill Strategy – due to seepage concerns, it is now planned that the final tailings surface will be RL -45m rather than -20m by 2020. It was noted that this strategy doesn’t take into account any additional contribution of tailings from the Ranger 3 Deeps project, but is based on optimisation of processing using currently available ore (which will depend on foreign exchange and other factors). ARRTC noted that the proposed schedule is ambitious. The extent to which the final backfill over Pit 3 is domed will depend on how much rock is needed to accommodate long term erosion and the maximum height consistent with meeting traditional owner expectations. ERA noted that the consolidation rate drives rock surcharge requirements and phased surcharge and landform activities are being planned to backfill consolidation “sinks’ as they develop. There was some discussion about the potential risks and contingencies related to the expected performance of the brine concentrator. ERA advised that the quality of permeate from the final plant will likely be better than the pilot plant as the latter didn’t have systems (i.e. chevrons) to remove aerosols. ERA advised the brine concentrator is a proven technology, but possible contingencies in the event that the distillate requires polishing to remove trace contaminants could include having more sentinel wetlands and perhaps using an ion exchange resin. It was also noted that the brine concentrator will produce permeate continuously throughout the year so disposal strategies for the wet and dry season will be developed to avoid the release of the brine concentrator permeate into the creek system during the dry season. ARRTC noted that Pit#1 is expected to be closed off by 2016. ERA proposes to use remotely operated dozers so that the pit can be backfilled while residual water is removed and treated. ERA plans to complete backfilling of Pit#1 by 2018. ALIGNING KKNS TO ITWC PFS ERA outlined the integrated elements of the pre- feasibility strategy for Pit#3 closure and associated activities, and how these relate to the Key Knowledge Needs. A review of all KKNs by ERA and SSD staff has been completed. This identified 63 activities or research projects that will need to be completed to inform the closure process. Several projects relate to multiple KKNs. The closure schedule is highly complex with many interlinks between various activities and decision points. A simplified schedule has been developed identifying deadlines for key closure criteria and regulatory approvals requirements. In relation to water quality closure criteria, further discussion is required to identify where these criteria will apply spatially in relation to components of the final landform, on site water bodies, and receiving waterways. ARRTC noted that this issue is being considered by the Closure Working Group and that the lack of an agreed final landform makes this process more difficult. ARRTC noted the prime source of cash flow for ERA during the period between cessation of mining in Pit#3 and possible mining in Ranger 3 Deeps would be derived from low grade ore processing to meet existing sales commitments. ERA informed ARRTC of the challenges in terms of the skills base and research required over the next few years. Key activities and cost drivers for progressive rehabilitation include rock/materials movement for pit underfill and capping, tailings transfer from the TSF to Pit 3 and ongoing water treatment up to final closure. In this context, ERA will need to retain essential labour and skills to effect its progressive rehabilitation and closure strategy.

ARRTC28-10: ARRTC commended ERA on the quality and depth of work being done on closure activities at Ranger and the high quality of information presented this meeting.

6.0 JOINT KKN REVIEW AND STATUS REPORTING (ERA/ERISS) The approach used for the review of the KKNs by SSD and ERA staff in preparation for jointly reporting of KKN status this meeting involved identifying all relevant tasks and activities related to engineering works, regulatory approvals, operational decisions and associated closure criteria, and prioritising these against the closure schedule. A “task leader” and critical dates were assigned for each activity/project under each KKN, and gaps and linkages between projects and KKNs were identified. A joint reporting template was developed which has been presented to ARRTC this meeting. It was noted that, in general, SSD’s historical focus has been predominately off-site (environmental protection) while ERA has focused both off-site (compliance) and on-site (control at source). ERA’s current research emphasis is on groundwater, water treatment and plant ecology/physiology while SSD’s focus is on freshwater ecology, ecotoxicology, geomorphology and landscape ecology. Areas of joint interest include environmental chemistry, environmental radioactivity and modelling (various) /GIS. In areas of over-lapping interest, care is required to avoid potential duplication of effort. ARRTC noted the key learnings from the joint KKN review included the need to continue improving coordination and integration between SSD and ERA research activities and to ensure better differentiation between operational and closure related knowledge needs. Other issues included the need to introduce a thematic issues-based narrative that covers relevant KKNs and the spatial and temporal scales for information required, and the need to reduce potential duplication between several KKNs. Relevant SSD and ERA staff then presented the status of each KKN. A number of more detailed technical presentations under selected KKNs were also provided to provide additional background for consideration by ARRTC.

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KKN REVIEW AND STATUS REPORTING2

KKN 1.1.1 - SURFACE WATER TRANSPORT OF RADIONUCLIDES

Discussion – ARRTC noted this KKN is on track and commended the proposed framework. There was agreement on the need to have separate KKNs for human health and aquatic biota, in line with ICRP recommendations. While no formal standard for non-human biota is available, there is an IAEA approach being adopted by ARPANSA in developing associated tools and guidelines (presentation to the next ARRTC to be considered). A mix of statutory, stakeholder assurance and time bound KKN reporting requirements was noted. Statutory monitoring results also inform operational and closure planning. Other issues and recommendations arising from discussion included the need to identify what information is specifically required, and that duplication in check (atmospheric) monitoring by SSD and ERA should be assessed and reviewed. ARRTC noted that given the very low risk to the public, independent check monitoring is not regarded as essential.

ARRTC28-11: ARRTC requested that SSD provide a presentation on ERICA and the ARPANSA approach on non-human biota to next meeting. ARRTC28-12: ARRTC agreed there should be a new separate KKN addressing radiation impacts on non-human biota.

KKN 1.1.2 - ATMOSPHERIC TRANSPORT OF RADIONUCLIDES Discussion – ARRTC noted this KKN is on track. It was noted the nature of the emission source term at Ranger will change with progressive closure and potential changes in operating conditions. Models and impact of this change on member of the public doses will need to be reviewed. ARRTC noted no changes are proposed and the KKN remains valid. KKN 1.2.1 - ECOLOGICAL RISKS VIA THE SURFACE WATER PATHWAY Discussion – ARRTC noted this KKN is on track and that key activities for 2012-13 include completion of the Contaminant Pathways Conceptual Model report (SSD) by Q3 2012 and on completing the Magela hydrodynamic model (ERA) for assessing near and far site impacts. Models have been developed (which include groundwater) and some quantitative assessment of risk has been undertaken. ARRTC noted this KKN is the cornerstone and rationale for much of the other research currently being undertaken by SSD and ERA. The work provides an overarching risk framework for the operational phase, and a similar framework for the decommissioning and post rehabilitation phases needs to be developed. This KKN is also relevant to the preamble to the KKN document and should therefore be considered in this context. ARRTC agreed the next step is to set up a process for developing the conceptual risk framework for the decommissioning and post rehabilitation (closure) phases. Following discussion, it was agreed that the closure phase should be divided into decommissioning, post-rehabilitation, and then long term post rehabilitation (meeting closure criteria, lease relinquishment, ongoing stewardship) components, all of which should be underpinned by a conceptual framework of how contaminants move through the system and potentially impact on identified receptors. ARRTC endorsed the need for developing such a conceptual framework and requested this be presented to the next meeting. Prof Boon offered to circulate to members an overview of the use of conceptual models in ecological rehabilitation.

ARRTC28-13: ARRTC requested a presentation be provided to next meeting outlining the conceptual framework for closure at Ranger (covering the decommissioning, post-rehabilitation, and long-term post rehabilitation phases). ARRTC28-14: Prof Boon to circulate to members an overview of the use of conceptual models in ecological rehabilitation.

KKN 1.2.2 - LAND IRRIGATION Discussion – ARRTC noted this KKN is on track. It was noted that although land irrigation will continue only for permeate and high quality waters there are potential issues and risks to the environment associated with using pure water. Changing the seasonal water application regime may also have an impact on vegetation resilience, which is important in terms of potentially expanding the area to be rehabilitated. Dieback of vegetation, and changes to the soil profile as a result of extended wetting can also liberate contaminants. It was noted there is currently no KKN addressing the rehabilitation of Land Application Areas (LAA) during the closure period, and perhaps the applicable KKN which is currently located in the operations KKN section should be moved to the rehabilitation section. Areas to be used for irrigating brine concentrator distillate have only been used periodically over the last few years for disposal of RO permeate or pond water. However, they will likely be used much more frequently and for extended periods once the brine concentrator becomes operational given the production rate of distillate. It was noted that Pit#1 will probably need irrigation to support initial vegetation establishment and that this, and dust suppression, could be a substantial use of both distillate (from process water treatment) and RO permeate (from pond water treatment) during the dry season. ERA currently irrigates permeate after it has been stored inRP1. During this process it mixes with other water and also picks up nutrients and organics, so this partly conditions the water before it is discharged to the environment. ARRTC noted that specific criteria will likely apply to the use of large scale irrigation in the initial phase of the rehabilitation process. There was discussion regarding the objective and ongoing need for this KKN, given the likely increasing need to redirect treated waters for use in rehabilitation. ARRTC noted projects under this KKN could be moved to another KKN (possibly KKN 2.5.4). KKN 1.2.3 - WETLAND FILTERS

2 Summary of discussion only recorded here - see Joint KKN Summary Report for further detail of KKN status and proposed changes.

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Discussion – ARRTC noted this KKN is on track and that wetland filter performance is reported in ERA wet season reports to stakeholders. ERA has tested use of the CCWLF for ammonia removal and will report on its efficiency in the future. Work under this KKN is feeding into developing the conditions required for establishing self-sustaining sentinel wetlands post decommissioning. ERA is not currently using RP1WLF and will rest the wetland for a period to allow it to regenerate. The current focus on breakdown conditions in RP1WLF is probably no longer required and focus should be shifted as to how wetlands can be developed to perform as sentinel polishing systems. It was noted the original aim for RP1WLF was to remove U, Ra and Mn while CCWLF was constructed for this purpose (for waste rock runoff) as well as for the stripping of low levels of ammonia from treated process water permeate. The current use of MF/RO to treat the entire annual pond water inventory, coupled with no treatment of process water means that the WLF are not being used for water treatment. However, depending on the final outcomes of toxicity work on brine concentrator distillate, they may be needed to remove some ammonia. It was suggested the KKN be refocused to how these WLF systems will perform during the closure phase. It was noted that distillate from the brine concentrator could initially be used to sustain sentinel wetlands during the dry given that the brine concentrator will need to remain operational for several years into the decommissioning period, if not beyond. ARRTC noted that information from this KKN will inform ecosystem reestablishment during and post rehabilitation (sentinel wetlands) and that the WLF systems may be required as long as the brine concentrator is operating. Key issues include how the WLF systems will deal with the higher loads during the initial years after rehabilitation, and the possible need for active management to mimic the wetting and drying cycles to maintain aquatic vegetation. KKN 1.2.4 – ECOTOXICOLOGY Discussion – ARRTC noted this KKN is mostly on track. Focus to date has been on the effects characterisation component of risk assessment with most projects undertaken by eriss. Proposed work includes determining trigger values for Mn and NH3, updating the U limit in surface waters (6-7 years since this was initially derived) and a large project looking at U toxicity in sediments. Work on suspended sediments will likely be deferred into 2013/14 owing to resource issue. ERA suggested expanding KKN to include activities that inform discharge strategies and regulatory decisions (e.g. mixing of different class waters, to facilitate water discharges). Previous research focus has been on Mg pulse exposures which are not really captured under KKN as currently worded. ARRTC noted this KKN remains relevant for the operational phase and obviously links to closure KKNs. It was proposed the KKN be updated and information added to strengthen the risk assessment component, especially related to U and Mg. Issues discussed included the need for further work looking at pH effects on speciation within off-Magela Creek waterbodies and further exploration of the use of mesocosms to investigate more complex assemblages than single species lab tests. It was noted that investigation of field effects gradients represented by unimpacted natural waterbodies through to retention ponds could also be considered, given the same contaminants that would be used in mesocosms are present in these ponds. The potential risks associated with the highly unlikely event of Magela Creek backflowing into Pit#3 were discussed. ARRTC noted the key issue is assessing the various risks to Pit#3 and ensuring these are appropriately controlled and mitigated, and further discussion may be required. ERA noted that appropriate mitigation strategies needed to be informed by the risk presented under such backflow conditions. KKN 1.2.5 - MASS BALANCES AND ANNUAL LOAD LIMITS Discussion – ARRTC noted this KKN is mostly on track, commenting that there is some confusion over whether this KKN applies on site or off site. Annual load limits (estimated at GS009) apply to radionuclides, metals and nutrients (but not MgSO4). The technical basis for annual load limits needs to be reviewed as they were developed many years ago and there is new knowledge and data. Arguably many of the load limits are so high as to be essentially irrelevant to the currently operating minesite. ERA undertakes real time EC flow monitoring at a number of waterbodies on site, and along Magela Creek, and has a release plan calculator used to manage releases based on water quality on site, and the flow regime in Magela Creek. ERA is refining a hydrodynamic surface water model which can predict the impact on water quality at 009 based on particular climatic/weather scenarios, and has also developed a solute balance module for the process water circuit to work with the OPSIM water balance model to provide confidence-based forecasts for solutes in the process water circuit under different water treatment and operating scenarios. SSD is deriving solute loads in Magela Creek (u/s & d/s) and this methodology will also be applied to Gulungul Creek. ARRTC noted that the current annual load limits haven’t been reviewed since they were first derived in the mid 80’s and should be revisited. It was agreed the off-site budgets and loads for solutes and sediments currently located in KKN 1.3.1 should be moved to this KKN. There was discussion in relation to the relevance of the current load limits and whether they are operationally redundant. It was noted that the load limits were based on the scenario of a possible RP2 release which has never happened, and that the current ecotoxicologically derived limits would be breached well before the load limits were reached. ARRTC noted this will be considered further by the Closure WG and could also be addressed as part of the risk pathway analysis for the closure phase. It was noted that the current Australian Water Quality guidelines (currently under review) prefer a biological (assimilative capacity) approach over a natural water quality based approach for setting limits. Another issue relates to what is deemed to be an acceptable detection limit (in terms of up/down stream comparisons) given that the pre mining condition is unknown since historical analytical detection limits were not low enough to measure the pre-mining concentration of U. KKN 1.3.1 - SURFACE WATER, GROUNDWATER, CHEMICAL, BIOLOGICAL, SEDIMENT, RADIOLOGICAL MONITORING Discussion – ARRTC noted this KKN is on track. ERA and SSD undertake a range of on and off-site monitoring activities, with a substantial amount being done to demonstrate compliance with the Authorisation and Environmental Requirements plus that

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done to support operational management and rehabilitation planning. Key issues discussed included the need to review the annual sediment monitoring program previously done by ERA, and which ceased several years ago, and the possible rationalisation of SSD’s atmospheric monitoring program. ERA suggested there is a need for a separate KKN that reviews water quality objectives and the compliance framework for the operational phase of mining. ERA collects monitoring data but there is currently no KKN that covers the compliance setting or reviewing water quality limits. It was suggested this could be incorporated as part of the ecotox KKN. ARRTC noted SSD has been moving away from using guidelines derived from reference conditions to deriving regulatory limits based on results from laboratory ecotox testing. This KKN covers a range of knowledge processes which feed into and inform a range of other KKNs. The key question being addressed is determining whether the environment remains protected and whether the current monitoring is the most appropriate, effective and efficient programme to detect any significant environmental impacts. ERA queried whether the current approach to monitoring should be reviewed to incorporate new technologies. It was noted that while monitoring per se may not be a key research knowledge need, the outputs from the various monitoring programs are important for informing much of SSD’s research programs, as well as its statutory role of ensuring that the environment of the ARR remains protected from the effects of U mining. While the information collected in ERA’s monitoring programs similarly feeds into their adaptive management programs and research to support rehabilitation planning. ARRTC agreed the key purpose of the KKN is to facilitate and support the other KKNs. It was noted that further detail on the relevant checkpoints in the process and a conceptualisation of the monitoring framework would be useful, and that sediments in billabongs remain a key knowledge gap under this KKN. ARRTC noted ERA has undertaken some work on sediments as part of the baseline survey for the Heap Leach EIS and in Corridor Creek, and is planning to do further risk assessment studies this year. ERA will discuss further with SSD to ensure this complements previous and planned work. ARRTC noted the need to ensure the significant amounts of data generated from monitoring programs are properly managed and collated and agreed that arrangements should be strengthened to facilitate data sharing between stakeholders where possible. It was noted that a separate new KKN was probably required to address the science required to inform regulatory decision making. KKN 2.1.1 - DEFINING THE REFERENCE STATE AND BASELINE DATA Discussion - ARRTC noted this KKN is mostly on track but that greater coordination between SSD and ERA is required to advance joint projects. ERA suggested the KKN should place greater emphasis on how to assess change from baseline conditions and the potential impacts of such change. SSD questioned the ongoing need for the KKN as much of the work is being addressed under other KKNs. There are two different reasons for identifying when change from natural conditions has occurred; determining the effect of that change and at what point this poses an issue for the environment. It was noted that Trigger Values (TVs) are designed to provide a sufficiently conservative basis for environmental protection before concentrations reach values at which environment harm could potentially occur. ERA noted that good guidance information on water quality (both ground and surface water) closure criteria is required to ensure the Pit#1 design (to be finalised by 2013) can meet these requirements in the long term. There are a number of interlinking issues including the need to understand the receiving water quality required to ensure appropriate engineering design, and the need for good quality data to determine the baseline condition. ARRTC noted that as the final rehabilitated landform will comprise broken fresh rock which will be subject to erosional and leaching processes, it will not be reasonable to expect closure criteria to be met during the initial phase (e.g. three years) of landform stabilisation. During this period the emphasis should be on engineering mitigation and active management to prevent/minimise off site impacts. It was agreed that further discussion in relation the rehabilitation ‘trajectory’ will be required, in the context of the performance assessment regime that will be in place until closure criteria are met. ARRTC noted CAESAR modelling shows that, 3-5 years after the landform is developed, the erosion rate from the final landform should reduce significantly.

TECHNICAL PRESENTATION (KKN 2.1.1) - DR JEFF TSANG Dr Tsang provided a presentation titled: Deriving Background Concentrations for Constituents of Concern in Groundwater and Soils. Key points noted by ARRTC and raised in discussion are outlined below. Groundwater background concentrations – This is a collaborative project between SSD, DoR and ERA. Previous studies (Ahmad & Green, 1986; Salama & Foley, 1997; Weaver et al. 2010) identified three different aquifer units at Ranger: alluvial and lateritic; weathered bedrock and fractured bedrock. Amad & Green (1986) sampled and analysed water from three different aquifers but the results were pooled. Salama & Foley (1997) characterised groundwaters around Ranger by aquifer type and host lithology. They looked at major ions but the work was more qualitative than quantitative. This work showed that the shallow aquifers are dominated by calcium and sodium and have low pH (probably due to low acidity of rainfall and low EC), and the fractured bedrock aquifer has low EC. The 2010 hydrogeological review of the TSF by Weaver et al reviewed previous literature and assessed groundwater quality. This work documented that there are 3 basic aquifer types in the vicinity of the TSF and that unimpacted groundwaters generally have low EC and SO4. There is no information in the Weaver report on how background conditions were derived, against which to assess changes through time. The report contains a statement that no breakthrough of SO4 was detected downgradient of the TSF. However, it was noted that the uptrending results for SO4 (from 1mg/l to 5 mg/l) may indicate a slight breakthrough due to seepage. Data from more bores needs to be analysed to get a more comprehensive and informative picture. The objective of the work presented is to undertake a site wide assessment of available data to establish background water quality in the three aquifers. The methods being considered for determining “background” concentrations include, using

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minima, maxima and means and applying a USEPA statistical approach to estimate background concentrations for constituents of concern. An additional aim is to determine whether further background sampling is required. Determining background (baseline) values involves identifying the constituents of concern which include EC, SO4, Mg, U, Ra, Mn and Ca. It was suggested that ammonium (for process water signature), water level and proximity to the ore body also be considered. Potential background bores will be identified using ERA’s GIS spatial and data aggregator to select bores with sulfate ≤5 mg/L. It was suggested that this approach may be introduce a somewhat subjective threshold by using a value of 5mg/l, and ERA agreed to look at this further. Other suggestions to identify mine source impacts included looking at principal component analysis and solute source fingerprinting (e.g. TSF versus RP2) in terms of signal baseline versus potential mine source (higher signals expected closer to source terms). It was noted there are potential issues with using historical data due to changes in detection limits (especially for U) and changes in the equipment and methods used for GW sampling through time. However, historical sulfate data should be OK in the context of changing detection limits. It was noted that screening interval is important in the context of ensuring that samples have been obtained from discrete aquifers - if deep bores are screened too widely they will access different lithologies. It was also noted that there are anomalous uraniferous expressions east of Pit#1 which could explain some of the higher results, as distinct from a mining influence. Using an overlay of geological data would assist with interpretation in this context. Background concentrations can be established for each constituent using either a parametric or non-parametric estimation technique (non-parametric technique when >50% of data were non-detectable, or when data set was non-normally distributed). Benefits from deriving background concentrations include establishing trigger values for monitoring groundwater, and improving the assessment of routine groundwater monitoring data. The US approach is being considered rather than the ANZECC/ARMCANZ approach due to the lack of available guidance material in the latter. It was noted however that relevant applicable guidance is available in the surface water guidelines. It was suggested that there is usually not enough baseline data available to do statistically valid analyses. It was also suggested that using the 80 percentile would be a more conservative approach, but this depends on context and the associated costs. ARRTC noted that the Weaver report showed some bores with very low SO4 levels but also showed trends that indicate ground water quality is changing. It was suggested the groundwater approach should be harmonised with the surface water approach. It was noted that, in relation to surface water, ERA has used the 80, 95 and 99.7 percentiles because while the ANZECC guidelines originally promoted using standard deviations when the data is normally distributed, guidance has shifted to using percentiles instead for all data distributions. It was noted that multivariate analysis would enable ERA to identify which bores are clustered and what is driving the observed changes. Background soil chemistry - Zimmerman and Lu (2011) reviewed historical and recent soil surveys at Ranger but only reported mean min and max range parameters. Further work applying parametric and non-parametric statistical analysis techniques is needed. ERA has collected hundreds of soil samples across sites (to 20cm depth) during a recent exploration survey which may be also be useful in deriving soil baseline concentrations. Samples from the southeast corner of the area are from land Application Areas (LAAs) and these will be excluded. Benefits from deriving background soil concentrations include allowing quantitative assessment of soil rehabilitation on the LAAs.

ARRTC28-15: ARRTC agreed that the ERA proposed approach of using existing data is sound, but that further data should be collected so that the derived trigger values can be reviewed and refined in the future.

TECHNICAL PRESENTATION (KKN 2.2.1) – MR JOHN LOWRY Mr Lowry provided a presentation titled: RUSLE, SIBERIA and CAESAR – the evolution of modelling landforms at SSD. Key points noted by ARRTC and raised in discussion are outlined below. Landform modelling directly informs the design of the initial rehabilitated landform since potential performance issues can be identified and rectified prior to construction. Three projects are planned for 2012-13 with the key priority to determine the geomorphic stability of early rehabilitation efforts on and around Pit#1, including influence of extreme weather events. Work on the trial landform will continue as the field measurements provide the means for validation of the model. There is ongoing discussion between SSD and ERA in relation to the applicability to landform design of parameters developed by Hollingsworth in the early 2000s from analysis of analogue terrains. It is anticipated that modelling of the Pit#1 backfilled landform will commence at the end of April 2012, but this is contingent on SSD receiving an updated DEM from ERA. The CAESAR landform evolution model will be enhanced by the model’s author to incorporate the effects of dynamic consolidation of the surcharged and backfilled pit. The next stage will be to upgrade the model to account for the effect of an evolving vegetation cover. This is a longer range issue that will draw heavily on the time series observational evidence from the trial landform. ERA asked if the CAESAR modelling will provide an indication of the sizing of sediment traps to handle sediment load so this can be included in rehabilitation costing. It was noted that Pit#1 modelling will be used as an initial trial and the method should be available to be applied to the whole landform by Q3 2012. It is also planned to link and combine the CAESAR and SIBERIA models to simulate the long term effects of erosion over 10,000 years. The biggest risks to the final landform will be during the first 10 years, as the surface is stabilising and vegetation growing, and the model will be used to simulate how the landform performs taking into account consolidation (for the backfilled pits) and extreme events. It was suggested it should be assumed for modelling purposes that vegetation is absent during the early phases of landform consolidation. It was noted that the model currently has a component for simulating the effects on runoff flow from surface cover (grass) by modifying shear stress (thickness and diameter of vegetation), but this needs to be calibrated. Engineering stresses caused by landform consolidation could also be significant and may require surface maintenance which could perturb

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vegetation in these areas. Grasses could be used as an initial protective cover over the capped Pit#1. ERA indicated it is not planning to initially revegetate the bulk of the landform, rather it is planned to revegetate Pit 1 from the outside toward the middle with the consolidating area being backfilled progressively with surcharged material and revegetation being conducted once the consolidation rate had reduced. ERA has been seeking views from TOs on landform design and this will continue. ARRTC noted the importance of not building up unrealistic expectations regarding the early rehabilitation phase. It was suggested that a new framework may be required to provide the basis for landform design. Landform design is currently done by ERA using information from consultations with TOs and a range of criteria, including height, slope, ecosystem and hydrology, and SSD then does predictive modelling looking at erosion stability, including export of suspended sediment. Several models have been developed for evaluating erosion and assessing landform stability but SSD is focusing on two 3D landform evolution models (SIBERIA and CAESAR) as they can simulate both erosion and deposition and can dynamically adjust the landscape to reflect this over the simulation duration. CAESAR is based on particle size distribution and is driven by rainfall so it can model effects of discrete extreme events (e.g. the 2006/07 flood event). ARRTC noted that the model can only deal with sediment bound loads, not dissolved solutes present in the water. A comparison, using CAESAR, of measured vs. modelled discharge and sediment yields (bedload and suspended) for the trial landform showed a high correlation, giving confidence in the predictive capacity of the model. Current issues include the need for a higher resolution DEM for running the model, ongoing field data to validate the models, and to ensure landform design takes account of all relevant factors including the views of TOs. It was agreed that the first 10 years will be the most vulnerable period in terms of the landform stability. It was noted that potential effects associated with having significant amounts of unconsolidated rock waste on the site are being addressed. ARRTC suggested that landform evolution modelling also be done for Nabarlek subject to resources and priorities. However, the current focus is on Ranger. It was noted that the Nabarlek cap has not been resurveyed recently, although a recent LIDAR acquisition of the area could provide sufficiently high resolution data. Questions were raised whether the model can assess the role of vegetation in terms of how it intercepts rainfall droplets and binding sediments and it was noted that the model doesn’t currently include tree canopy area, and is only based on grass cover as a shear stress modifier (however developing a vegetation model is feasible). It was noted that although vegetation will reduce infiltration to the landform during extreme rainfall events it will be susceptible to fire and push down from cyclones.

TECHNICAL PRESENTATION - DR ANJA ZIMMERMANN Dr Zimmermann provided a presentation titled: Investigations into the Potential Seed Provenance for Ranger Mines Revegetation. Key points noted by ARRTC and raised in discussion are outlined below. The Ranger mine authorisation requires the Project Area to be revegetated using local native species but doesn’t define “local”. In the absence of a definition or genetic derivation of local provenance, a conservative seed collection zone consisting of a 30 km radius from Ranger Mine was proposed in the ERA’s draft revegetation strategy in 2004 (Reddell & Meek 2004). The relatively small radius was to ensure that the genetic make-up of the revegetation is consistent with local populations. It was noted that the stipulated 30km radius poses a major risk to Ranger mine revegetation due to difficulties in obtaining sufficient seeds from certain species and in obtaining seed collection permits from KNP. The main revegetation species, the Darwin Stringybark (E. tetrodonta), has low seed production and seeding is impacted by fire and extreme weather events. The term “local native plant species” has been taken to mean plant species of local provenance which have home site advantage due to adaptation to the region’s climate, soils and environmental conditions. There is significant debate in the recent literature in relation to the value of genetic diversity in minesite rehabilitation. However, the general consensus is that genetic diversity provides for successful rehabilitation outcomes as long as the climatic and environmental conditions between the seed collection site and the rehabilitation site are sufficiently close. This “Composite Provenancing” approach involved identifying similar environmental zones to the Ranger site following guidelines developed by FloraBank and Greening Australia with some modifications. Factors considered included species variations, species distribution, species adaptations, potential gene flow, and potential geographic and ecological distribution limitations. The work identified that the environmental characteristics of the Ranger site are very common across the region and that there are no indications of genetic variation. Based on this, a Conservative Provenance Zone was identified and each species was then assessed in terms of its distribution, genetic make-up, habitat preferences, ecology, pollination biology and seed dispersal. Guidelines for seed collection within the Conservative Provenance Zone further define the vegetation community and local environmental characteristics. Key conclusions from this work are that seeds collected within the Conservative Provenance Zone should be well adapted to the current conditions of the Ranger Mine, provide sufficient genetic diversity to prevent inbreeding, promote the plants adaptive potential and consequently future proof the revegetation to the some extent against changes in climate. The study also indicates there may be value to sourcing seeds from environments dissimilar to Ranger as well as they may deal better with potential changes in local climate, although they may struggle under present environmental conditions at Ranger. It was noted that there are a number of gene flow proxies and it was suggested that species at extremes of those ranges identified by the CPZ also be looked at. Parks Australia and TO approval will be required before the landform will be able to be incorporated into KNP, so it is important to resolve the provenance issue at an early stage. ARRTC noted that less common or widely distributed species have also been looked at but there are not many species that have a limited distribution range. It was noted that fire and other factors affect seed availability, and that translocating any organism involves some level of risk. While it is best to use local seeds, if this is not possible, it is acceptable to have success using seeds from slightly further away that may

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be hardier. It was noted that some gene flow may be possible due to birds. It was suggested that either inbreeding or gene flow can occur, but not both concurrently. It was noted a key risk is whether there will be sufficient seeds and plants available when required, and that risk assessments by ERA had also identified the lack of seeds as being a key risk. ERA advised the 30km limit was self imposed and is not stipulated in the Authorisation. KKN 2.2.2 - DEVELOPMENT AND AGREEMENT OF CLOSURE CRITERIA FROM THE LANDFORM PERSPECTIVE Discussion – ARRTC noted this KKN is mostly on track and remains relevant, but there is a need to look at overlaps with other KKNs. It was noted the Closure Criteria Working Group will continue to hold regular meetings. KKN 2.2.3 - WATER QUALITY IN SEEPAGE AND RUNOFF FROM THE FINAL LANDFORM Discussion – ARRTC noted this KKN is mostly on track and ERA’s work on modelling is continuing. It was noted that the erosion outputs from CAESAR modelling can be used as inputs to the hydrodynamic modelling. ERA is also looking at whether solute modelling could be done through SIBERIA or CAESAR but it was agreed the hydrodynamic model would be better for this purpose. It was suggested some form of baseline database is required and that the KKN also links to sentinel wetland design and vegetation issues. Solute source modelling by Intera will focus on waste rock to be buried as backfill into the pits and remaining in reshaped above ground structures. The effects of different saturation conditions will be explored. It was suggested that water quality aspects of this KKN should not be limited to salinity and turbidity, as these are bulk parameters that do not specifically address the solutes of most concern. Current problems with measuring turbidity from the landform due to platey mica particles were noted. It was suggested that changes to this KKN be considered following the proposed risk assessment work on the decommissioning and rehabilitation phases. SSD is continuing work to resolve the technical issues posed by measuring turbidity of platy reflective schist or mica particles. ARRTC noted the need to develop reliable and accurate methods for measuring turbidity in surface runoff from the rehabilitated landform. KKN 2.2.4 - GEOMORPHIC BEHAVIOUR AND EVOLUTION OF THE LANDSCAPE Discussion – ARRTC noted that there are a number of projects proposed under this KKN but SSD may have difficulty completing this work due to staff shortages. Staff development is required and further refinement of the CAESAR landform evolution model is needed (ERA is supporting Professor Tom Coulthard’s involvement with the application of his CAESAR model to the prediction of the stability of the rehabilitated mine site over 10000 years following rehabilitation, and a three week secondment with SSD in late June). The 10,000 yr containment requirement only applies to tailings which will be placed well below grade in the backfilled pits. It was noted that when the Ranger Authorisation was renewed, physical tailings and their derived solutes were both considered. There was discussion in relation to the relevance of the 10,000 year requirement for tailings isolation when the above grade component of the final landform will be at greatest risk during the first 10 years. It was suggested that, as climatic variability drives groundwater level, it would be useful to keep modelling out to 10,000 yrs in order to link transpiration and recharge modelling, and assess the effects of this on groundwater elevation –especially in relation to the backfilled pits. It was suggested that shallow interflow is likely to be the main issue driving transport of solutes from the landform. It was suggested that based on modelling results to date, good modelling will be required during the first 20 years as this is critical for landscape design. It was suggested this highlights the need for an agreed extreme event sequence to be applied. ARRTC noted that to date only one extreme event (30% PMP) for which actual rainfall data exists has been modelled. Based on work by Wasson and others there have been larger historical events than the 30%. There is a need to consider how to factor PMP into modelling more generally. KKN 2.2.5 - RADIOLOGICAL CHARACTERISTICS OF THE FINAL LANDFORM Discussion – ARRTC noted this KKN is mostly on track. It was noted that the KKN addresses two requirements; determining the characteristics of the final landform and determining what the pre-mining characteristics were. It was agreed it is important to determine TO expectations regarding proposed landuse of the final landform and incorporate these into the dose model to identify key risk areas. The work under the KKN is moving from high level criteria (e.g. dose limits and constraints) to targets for landform design/practice. It was noted that exposure scenarios and near field inhalation doses need to be established, and that near field conditions are very different to far field conditions. SSD is addressing radon exhalation and reviewing outcomes of the ERA review of information requirements for closure. Results for radon are temperature/pressure dependent and the consequence of temperature observed whereby the radon is trapped closer to ground level. There was some discussion regarding the dose limits that would apply to the final landform and the implications of this for land use by TOs. It was suggested that the post mining levels would be expected to be less than pre-mining given the orebodies are no longer exposed at the surface. It was suggested that the TSF wall should be disposed of in the Pits in order to remove one of the source terms. ERA advised that information on whether the site is going to be subject to some degree of land use restrictions is required so consultations with TOs can be further progressed. It was noted that TOs may have some unrealistic expectations regarding final land use. ARRTC agreed this is a critical issue which informs a range of design parameters for the final landform. It was suggested that perhaps the issue of access to the land in the intermediate term after rehabilitation is not as critical as might be first thought , as TOs already expect that there will be exclusion zones and don’t see that changing over many decades. It was noted this is mainly based on perceptions. It was suggested that absolute gamma radon flux rates would be good to have but probably aren’t required. It was noted that there are closure criteria relating to this but there is a need to determine exactly what the criteria mean in terms of targets for landform design. This is not straightforward because it includes having dose models and expected land use. It was noted that the South Australian EPA has similar issues and is currently developing guidance for closure of

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uranium mines. There are a number of source terms around the Ranger site which will add to total dose for the site, so Pit#1 constraints need to take that into account. It was suggested that Pit#1 is different to Pit#3 as there are different amounts of waste rock involved and Pit#3 will have lower grade material. It was noted this has been looked at previously by Dr Mudd and was considered in a study by the AEC in the 1980s. ERA noted stockpile volumes and grades at locations across the site can be determined from their records.

TECHNICAL PRESENTATION – MR NATHANIEL TOLL Mr Toll provided a presentation titled: Ranger Groundwater Investigations and Modelling and provided an update on the status of various groundwater studies at Ranger. Key points noted by ARRTC and raised in discussion are outlined below. Tailings Storage Facility (TSF) – most of the recommendations arising from the TSF Working Group review in 2010 are complete or in progress. A number of these are multi-year projects. A total of 78 new bores have been installed and two refitted. Quarterly sampling is ongoing in these and the existing 23 bores, making a total of 103 bores. Data analysis is ongoing to develop a conceptual model of flow and transport at the TSF and to construct a revised numerical model of flow and transport. The 13 nested sites include bores at different depths. There are no surprises from the SO4 results and the excursion to the North along the fault 2A shows up well in data - most SO4 increases are located close to the TSF. These results are the same as modelling and other sampling results. Recent sampling shows a hotspot southwest of the TSF, adjacent to the toe of the TSF wall, and some of the concentrations are quite high. In terms of depth stratification, seepage is confined to aquifer 1 and 2 predominantly. The model appears to be over-predicting the distance the contaminations is travelling. ERA will do further step out drilling in select areas to provide a higher level of confidence. It was noted that water levels in the bores closer to the TSF are lower than expected and it was suggested some of these bores are located in areas of low permeability so are still recovering. There are significant differences between the bores closest to the TSF and in Gulungul Creek about 200m away. ERA is getting a better idea of what is happening between the bores. The elevated solute values in tributary areas are believed to be due to intrusion of surface water containing elevated levels of solutes derived from leaching from rock armoured wall of the TSF. Results from the nested sites support this result. The U results indicate that U is still being attenuated (apart from the one site on the southwest toe of the TSF). The preliminary findings from the TSF review are that: 1. analytical results from TSF bores show less lateral impact than predicted by recent modelling of solute transport from the

TSF, 2. the depth of impact from TSF seepage is shallower than the modelling suggests; 3. the magnitude of the observed concentrations is higher than modelled immediately adjacent to the dam footprint; and 4. observed SO4 concentrations suggest that the source concentration used in previous TSF modelling was too low, and that

the hot spot in the southwest corner of the TSF needs to be further characterised. Pit#1 solute transport characterisation – CSIRO has been engaged in a project to predict long-term geochemical conditions and solute generation of tailings in Pit#1, assess the balance over time of water and solutes within the backfill overlying tailings in Pit#1, and evaluate the attenuation/reactive processes affecting seepage, subsurface transport and interaction of seepage with the surface water systems. The first two tasks have been completed and task 3 is ongoing. The tracer test in Pit#1 in December 2011 using sodium bromide had not observed any break-through which given the large gradient and short distance involved is puzzling. Examination of fractures had been done. The test duration was 82 hrs at a depth of 35m. The design of the recovery bore array is being reassessed prior to doing any more injection test work. It was suggested that if ERA had used process water for this test that the lack of recovery would have been of concern. ERA’s initial proposal was that process water be used as a tracer once it was demonstrated with the NaBr tracer that it was possible to recover the test fluids. Ms Coram noted that there could be good reason to use process water as a tracer and offered to review and comment on the rationale and importance of such a test if ERA provided the detail. Pit#3 solute transport simulation – This information is required by ERA to inform closure costings. The conservative solute 2D simulation is complete and shows that brines injected to the bottom of Pit#3 can be confined for 10,000 yrs. It was noted that the groundwater flow models for the Pit#1 and Pit#3 domains have been combined as the location of the divide between the Pit#1 and Pit#3 groundwater systems is currently unknown. Key conceptual model components – The processes and features that govern solute loading from Ranger mine to Magela Creek include the hydrolithology, flow driven by topography and seasonal precipitation, seasonal water transfers between groundwater and surface water and the various solute source terms. It was noted the plume under the plant area is yet to be fully characterised but data to date indicates that the contaminant transport rates are slow enough that no intervention is required ahead of scheduled rehabilitation of the plant area. Surface water modelling – Surface water modelling is required to assess concentrations of contaminants of concern in creeks and billabongs. Further information is required on how frequently and to what extent surface expression of groundwater will occur and contribute to surface water flows and quality. The behaviour of billabongs and their role as solute traps and storages also need further investigation. The hydrodynamic model being developed will address aspects of this. Magela hydrodynamic model – This project is being undertaken by the Australian Institute of marine Science. Stage 1 is looking at Magela Creek and stage 2 will involve expanding the model to include sub catchments at Ranger to simulate post closure flows and solute transport in surface water systems.

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Systems model – This work is developing a systems modelling approach to aggregate results from all of the current models to allow the behaviour of the whole site to be assessed under a range of future climatic and environmental scenarios. ARRTC commended ERA on the systems model which will provide an improved understanding of the various components of the system and their inter-linkages, and the excellent progress to date in implementing the Weaver review recommendations.

ARRTC28-16: ARRTC commended ERA on the quality of current groundwater modelling work and the good progress to date in implementing the Weaver report recommendations.

KKN 2.3.1 - CONTAINMENT OF TAILINGS AND OTHER MINE WASTES Discussion – ARRTC noted this KKN is mostly on track, but that it overlaps to a large extent with other KKNs (2.3.X) dealing with potential impacts associated with the rehabilitated pits. This overlap should be reduced if possible by combining or rationalising the relevant KKNs. It was noted that the proposed projects and monitoring will continue, and that other projects will be identified as part of the PFS. KKN 2.3.2 - GEOCHEMICAL CHARACTERISATION OF SOURCE TERMS Discussion – ARRTC noted that projects under this KKN are at various stages of progress. It was noted this KKN overlaps with other groundwater KKNs. KKN 2.3.3 - AQUIFER CHARACTERISATION AND WHOLE-OF-SITE MODEL Discussion – ARRTC noted this KKN is on track. It was noted that existing hydrocarbon contamination under the plant is not considered to present a high risk for closure. SSD is involved in the radionuclides component of groundwater modelling. The whole-of-site modelling aspect of this KKN overlaps with KKN 2.3.4. KKN 2.3.4 - HYDROLOGICAL/HYDROGEOCHEMICAL MODELING Discussion – ARRTC noted this KKN is on track and that the whole-of-site component of KKN 2.3.3 should be incorporated into this KKN. KKN 2.4.1 - ACTIVE TREATMENT TECHNOLOGIES FOR SPECIFIC MINE WATERS Discussion – ARRTC noted components under this KKN dealing with closure options assessment are on track but those dealing with treating the current inventory of process water have been delayed. It was noted this KKN remains relevant. KKN 2.4.2 - PASSIVE TREATMENT OF WATERS FROM THE REHABILITATED LANDFORM Discussion – ARRTC noted this KKN is behind schedule and further discussions between ERA and SSD on this and other KKNs related to establishing sustainable aquatic ecosystems are required. It was noted that previous studies have addressed various aspects of this KKN but further studies are required. It was agreed that the status of this KKN should be determined following the joint review. ERA suggested further discussion is required to determine whether “sentinel wetlands” are functional aquatic ecosystems constructed to address TO expectations or just engineering structures for capturing sediment and removing solutes coming off the final landform. It was noted that the ecological knowledge needed to construct sustainable polishing wetlands will also be applicable to the reinstatement of the former Djalkmarra billabong. Other issues that need to be resolved include the lifetime of these structures and the maintenance regimes (e.g. periodic removal of contaminated sediment) and whether they should be designed as ephemeral or perennially wet systems. It was asked if the location of such wetlands has been incorporated into the conceptual DEM for the final landform as yet. ERA advised that the bunds along RP1 have been removed in the current landform DEM but that further iterations incorporating sediment control and wetland basins are required so that the fitness for purpose of these structures can be tested by the geomorphic modelling. ERA raised the issue of where contaminated sediment would be placed when these structures are decommissioned since that will occur some years after the rest of the rehabilitation has been completed. KKN 2.5.1 - DEVELOPMENT AND AGREEMENT OF CLOSURE CRITERIA FROM ECOSYSTEM ESTABLISHMENT PERSPECTIVE Discussion – ARRTC noted this KKN is mostly on track. A high level framework taking account of relevant temporal and spatial scales is required to guide the development of closure criteria. It was recommended that greater coordination is needed between SSD-ERA to better define closure criteria needs and research required for establishment of sustainable terrestrial and aquatic ecosystems. A conceptual model is also required to take account of different stages of rehabilitation and closure in so far as this may affect physical maintenance requirements and the impact of this on revegetation. Different methods are being used to develop closure criteria for aquatic and terrestrial components. Work on aquatic criteria is well advanced with much field observational and ecotox work having been done, however criteria for aquatic ecosystems relating to re-establishing plants and habitats is not as advanced. Whilst work on terrestrial criteria has been delayed, there is good information available on plant density and compositional data, and terrain analysis that will inform aesthetic aspects of final landform design. It was noted the substantive progress on the laboratory project to develop numerical criteria for suspended sediment concentration will likely be pushed out to 2013/14 owing to resourcing issues in SSD. However, opportunistic field work will continue, depending on occurrence of relevant magnitude turbidity events in Georgetown and other billabongs. It was suggested that the current KKNs should be updated to reflect the increasing focus on the decommissioning and post rehabilitation phases. There is also a cultural component in setting water related closure criteria in light of TO expectations regarding waterway health and keystone species etc. This is lagging behind the other technical criteria but will need to be included. It was noted that ERA has already

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commenced projects addressing this aspect. KKN 2.5.2 - CHARACTERISATION OF TERRESTRIAL AND AQUATIC ECOSYSTEM TYPES AT ANALOGUE SITES Discussion – ARRTC noted that work on terrestrial aspects of this KKN is on track but work on aquatic aspects is behind schedule (apart from some work on sediments). It was recommended that the KKN be divided into terrestrial and aquatic components. It was noted that this KKN has significant overlaps with other KKNs which need to be addressed. There is a particular overlap with defining reference state equivalent to analogue site. ARRTC noted that the ERA investigation into some growth abnormalities in vegetation on the trial landform has not shown any causal factors for the observed morphological effects as yet. KKN 2.5.3 - ESTABLISHMENT AND SUSTAINABILITY OF ECOSYSTEMS ON MINE LANDFORM Discussion – ARRTC noted this KKN is closely linked to KKN 2.5.2, and that work on terrestrial components is on track but aquatic components are not as advanced. Additional proposed infill planting on the trial landform relates to canopy species. ERA is starting to look at understorey species to plant out once the canopy cover has been established. It was noted this KKN links and overlaps with a number of other KKNs. ERA has some prior experience in establishing aquatic ecosystems (i.e. WLFs onsite). It was recommended that the KKN be split into separate terrestrial and aquatic components. KKN 2.5.4 - RADIATION EXPOSURE PATHWAYS ASSOCIATED WITH ECOSYSTEM RE-ESTABLISHMENT Discussion – ARRTC noted this KKN is mostly on track. Further discussions between ERA and SSD are planned in relation to radiation exposure pathways associated with ecosystem establishment and how to address impacts on non–human biota. It was agreed the database tool (BRUCE) will assist in determining radiological impacts on non-human biota. It was noted that diet has been reviewed by ERA, and that initial results indicate that Po210 (in pigs) may be the major source of post rehabilitation radiation dose. Further work on concentration factors is required. It was suggested that the KKN be revised to include non-human biota impacts. KKN 2.6.1 - MONITORING OF THE REHABILITATED LANDFORM Discussion – ARRTC noted that monitoring programs for the post rehabilitation phase have not yet been developed but work informing this is continuing as part of the development of closure criteria. It was agreed this KKN remains relevant. It was noted that remote sensing can provide various lines of evidence for post rehabilitation monitoring, especially in the context of the research that the SSD Spatial Sciences and data Integration group is doing on a range of methods and technologies. It was noted that using remote sensing has benefits over ground-based survey methods for some parameters being monitored. It was noted that SSD remote sensing work will link with existing ERA terrestrial analogue sites projects and that the focus is moving away from community level detail to structural classification. It was agreed that R&D needs to commence now if remote sensing methods are to be ready to be used for post rehabilitation monitoring (e.g. looking at water vapour, cloud and fire smoke limitations on capture windows). It was suggested that the remote sensing monitoring program would be more appropriately reported at the KKN 2.6 level. KKN 2.6.2 - OFF-SITE MONITORING DURING AND FOLLOWING REHABILITATION Discussion – ARRTC noted that the off-site monitoring program during and following rehabilitation will be developed once the closure criteria have been determined. It was agreed there is a need to determine what constitutes offsite, specifically in the context of where closure criteria will apply. It was noted that work has commenced on vegetation community mapping and work is ongoing on weed monitoring in vegetation analogue areas and developing basic understanding of floodplain vegetation. Monitoring of the offsite landscape environment will provide baseline and reference sites against which to assess any post rehabilitation impacts from the site, and also to provide an indication of the extent to which rehabilitated areas are being impacted by offsite pressures (e.g. weeds). Although ERA has five years of weed mapping data It was noted further work is required to compare this mapping data with remote sensing approaches as the scales of acquisition are different. It was noted that UAV’s have capability to do hyper-spectral capture but the required equipment is very expensive (approx $250,000). It was noted that the proposed risk assessment should look at effects and risks off site as well as on site. Weed monitoring will still be required offsite to assess risks associated with potential re-invasion of the final landform. ARRTC noted that a cautious approach is required to ensure the research questions are clearly defined, rather than developing a tool and then looking for applications. Experience at Djarr Djarr where weeds contributed in a major way to the destruction of initially successful revegetation by fire was noted. A number of members expressed concern that the specific knowledge gaps and research questions being targeted by this work are not immediately obvious, and these need to be better defined before proceeding. KKN 2.7.1 - ECOLOGICAL RISK ASSESSMENTS OF THE REHABILITATION AND POST-REHABILITATION PHASES Discussion – ARRTC noted that work addressing this KKN is yet to commence. It was suggested that ecological risk assessment of the rehabilitation and post-rehabilitation phases should be higher up in the rehabilitation phase KKNs. It was noted that the risk assessment framework for the rehabilitation phase hasn’t been done as yet but there is significant information available to feed into this. It was suggested that this KKN needs to be better integrated with other risk assessment KKNs. It was noted that ERA will be engaging an expert to undertake a Features-Events-Processes analysis of the rehabilitated site which will look at key risks from events and processes that could impact on the site. The results of this work will be fed into proposed joint risk workshop to be held in July. It was noted this KKN links to the stewardship KKN. ARRTC agreed that the proposed risk workshop should be facilitated by an external expert and build on the existing operational phase conceptual model and associated pathway risk assessments. It was also noted that KKN 5.1.1 dealing broader landscape risk assessment is also relevant to this KKN and could be merged.

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KKN 2.8 - STEWARDSHIP Discussion – ARRTC noted this KKN is mostly on track. It was noted that stewardship in this context is often confused with Product Stewardship so it was suggested to add “Land” to title. ARRTC agreed the concept applies to the operational, decommissioning, rehabilitation, and post rehabilitation phases. It was also noted that the progressive rehabilitation pilot projects fall under this KKN as do the Caring for Country rehabilitation projects. ARRTC noted that Dr Lu’s group in ERA is working with TOs looking at burning trials. It was noted there are also linkages between this KKN and other KKNs dealing with TO cultural knowledge and this should be made more explicit. Clarification is required regarding the allocation of responsibility for the site after ERA hands it back. It was suggested that including such legal questions may make the KKN too broad. Stewardship is a broad theme that runs through a range of KKNs rather than just this KKN. ARRTC noted that Dr Howard Smith (NLC) sees traditional ecological knowledge as being complementary to the western science and wants to see TO knowledge incorporated with scientific knowledge up front. It was noted that SSD was established to address environment protection not the cultural values, and that significant work on how to protect the cultural values is being done by other organisations such as GAC and NLC. It was suggested that the fact that successful rehabilitation requires TO support and signoff should be identified as a potential risk if agreement is not obtained. ARRTC noted that ERA is currently testing its approach to TO engagement in rehabilitation through a number of pilot projects. ERA may need to look at using indigenous indices as measures of success as used in New Zealand. It was noted the level and availability of Traditional Knowledge that can be used to plan and assess rehabilitation will vary depending a number of issues. It was noted this presents a significant challenge given the range of issues where information is required by the end of 2013. ARRTC agreed it would be useful to have a presentation from Dr Smith on these issues.

ARRTC28-17: ARRTC requested that Dr Smith provide a presentation to next meeting on the integration of Aboriginal Traditional Knowledge (and expectations) into the closure planning process.

KKN 5.1.1 - DEVELOP A LANDSCAPE-SCALE ECOLOGICAL RISK ASSESSMENT FRAMEWORK FOR THE MAGELA CATCHMENT THAT INCORPORATES, AND PLACES INTO CONTEXT, URANIUM MINING ACTIVITIES AND RELEVANT REGIONAL LANDSCAPE PROCESSES AND THREATS, AND THAT BUILDS ON PREVIOUS WORK FOR THE MAGELA FLOODPLAIN Discussion – ARRTC noted that some aspects of this KKN have progressed but there is still a need to agree on a framework for landscape scale assessment that will incorporate traditional knowledge and points of view. It was noted this KKN remains relevant and could be consolidated with the other risk assessment related KKNs. KKN 5.2.1 - ASSESSMENT OF PAST MINING AND MILLING SITES IN THE SOUTH ALLIGATOR RIVER VALLEY Discussion – ARRTC noted this KKN is on track. It was noted that the results of monitoring on the El Sherana containment (including Radon exhalation) will feed into other KKNs and work on criteria for final landform. It was noted this is expected to be much higher than that expected for the Ranger cover. Dr Sinclair noted this is relatively low grade material. Dr Bollhöfer suggested the areas covered by waste rock are likely to be the main sources and Dr Jones noted the 1sqkm bottom of the TSF will also be a source. KKN 5.3.1 BASELINE STUDIES FOR BIOLOGICAL ASSESSMENT IN WEST ARNHEM LAND Discussion – ARRTC noted this KKN is not considered to be of high priority. It was agreed that developing a monitoring program related to West Arnhem exploration activities could be looked at further in the event the need arises.

DISCUSSION ON NEXT STEPS ARRTC recognised the significant work by ERA and SSD staff in developing the joint reporting framework for this meeting. There were different suggestions regarding how to further progress this work including that ARRTC have a workshop out-of-session or that ERA/SSD prepare an initial draft and then review and endorse at next meeting. It was agreed the next steps are to develop a risk assessment and thematic architecture based on what Ms Coram proposed. It was noted that the current budget limitations might preclude the workshop option. An SSD-ERA risk workshop to address the decommissioning and rehabilitation phases has already been planned. This work will build on the detailed analysis that has already been done for the operational phase. It was agreed the risk assessment workshop would more clearly refine architecture required which could be presented to ARRTC for review. ARRTC noted that the main phases that should be considered are: operational, decommissioning/rehabilitation, stabilisation/equilibrium and long term post closure. It was suggested that ARRTC prioritise the key knowledge gaps based on the outcomes from the risk assessment workshop. It was agreed a risk based approach is required that is similar to what was done for the operational phase. It was noted this will be difficult to manage via email or teleconf and ARRTC really needs to be engaged. It was noted the other option is for ERA/SSD to develop the framework and present this to the next ARRTC meeting. It was suggested ARRTC should avoid passing this work to next meeting. It was recommended the focus be placed on the KKN2.X group due to the urgency on the rehabilitation related KKNs, with a key task being rationalisation of the current KKNs according to the outcomes from the KKN review documented above. A further option may be for a small group of ARRTC members to be involved similar to the approach employed when ARRTC reviewed the last version of the KKNs. ARRTC agreed that it is important that the linkages between the old KKNs and the proposed new KKN structure be cross-referenced to assist in interpretation, and as resources are limited, the process should focus on closure related knowledge needs.

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ARRTC28-18: ARRTC agreed that ERA and SSD should undertake further work as part of the proposed risk assessment process to draft a risk based framework for prioritising the KKNs associated with the decommissioning and rehabilitation phases at the Ranger mine. ARRTC agreed members will be involved where possible in person by or email/teleconf. ARRTC28-19: ARRTC agreed to look at the feasibility of holding a one day workshop in Canberra in September 2012 to enable members to review and comment on the draft risk framework and revised KKNs. ARRTC28-20: ARRTC agreed that, consistent with the approach agreed last meeting, the draft revised KKNs would be reviewed at the November 2012 meeting on a by exception basis.

1.5 GOVERNANCE (CONTINUED FROM DAY 1) Dr Sinclair stated the key governance issues associated with ERA’s involvement with ARRTC are (1) ensuring no inadvertent disclosure of market sensitive information consistent with ERA’s legal obligations under continuous disclosure and antitrust laws and associated statutory requirements; and (2) ensuring ERA’s complies with its legally binding obligations regarding third party Intellectual Property, especially when undertaking joint work and presenting technical performance information to ARRTC. Dr Sinclair advised that ERA will exercise due diligence when presenting information to ARRTC to ensure any confidential information is appropriately identified and if necessary removed from presentations and written reports, prior to posting on the website. He noted that while ARRTC members may have a legally enforceable non-disclosure obligation, this does not meet the requirements for release of commercially and/or market sensitive information. Mr Parker noted that under existing operating arrangements for ARRTC, industry members of ARRTC have mutually agreed to absent themselves from meetings when other industry members are presenting potentially commercially sensitive information. Mr Parker advised the proposed Terms of Appointment also include the standard Australian Government non-disclosure clause. He advised that the draft Terms of Appointment will be circulated to members out-of-session once they have been cleared by the Department. He requested all members review the document and advise any issues.

ARRTC28-21: ARRTC noted the Secretariat will finalise the draft ARRTC Terms of Appointment form and circulate to members out-of-session.

7 OTHER BUSINESS 7.1 KNOWLEDGE MANAGEMENT ACTIVITIES 7.2 SSD Publications since ARRTC26 A list of SSD publications since last meeting was tabled. 7.3 ERA Publications since ARRTC26 A list of ERA publications since last meeting was tabled.

8 OTHER BUSINESS It was agreed that the next ARRTC meeting would be held in the second half of November 2012 and would be preceded by a field trip to Ranger Mine. Members are to advise the Secretariat on their availability for this period.

ARRTC28-22: ARRTC agreed that members would advise the Secretariat of their availability for the last two weeks of September and November 2012.

9 MEETING CLOSE The meeting closed at 6.30pm. Mr Scott Parker ARRTC Secretary 08 89201122

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ARRTC28 – ACTIONS/OUTCOMES Action/Outcome Responsibility Status Carried over ARRTC27-4 ARRTC requested Ms Paulka to seek agreement from UEL to provide closure criteria and Hydrogeological review reports to Prof

Mulligan and Gavin Mudd. Ms Taylor UEL to address

Carried over ARRTC27-5 ARRTC agreed that UEL be invited to submit a proposal to amend the KKN and that ARRTC then consider based on the evidence that

has been provided to support this. Ms Taylor UEL to address

Carried over ARRTC28 ARRTC28-1 ARRTC approved the ARRTC27 meeting summary as tabled with one minor amendment (p.20). Secretariat ARRTC28-2 ARRTC agreed that the meeting summary for this and future meetings should be more concise and should aim to capture the key

discussion points and outcomes of the meeting without attributing individual members. Secretariat

ARRTC28-3 ARRTC agreed the draft actions should be circulated to members within 4 weeks of each meeting, and the draft minutes circulated within 8 weeks.

Secretariat

ARRTC28-4 ARRTC requested that DoR provide the outcomes of ongoing work on the new Maximum Operating Level to members out-of-session.

Mr Ball

ARRTC28-5 ARRTC requested that DoR and ERA circulate their respective reports from the Bureau of Meteorology on Probable Maximum Precipitation.

Mr Ball, Dr Sinclair

ARRTC28-6 ARRTC requested that Parks Australia provide a copy of the O’Kanes Pty Ltd proposal (if possible) and further details on the groundwater monitoring program being put in place for the SAV rehabilitation project.

Ms Morgan

ARRTC28- 7 ARRTC requested that the Secretariat circulate the SSD report to ARRAC37 to members, and that SSD ARRAC reports be circulated with the draft ARRTC minutes for future meetings

Secretariat

ARRTC28-8 ARRTC noted the implications of current budget constraints in terms of the prioritisation and possible deferral of some SSD research activities for 2012-13.

ARRTC

ARRTC28-9 ARRTC commended SSD staff on the quality of their 2012-13 Research Report and technical presentations to this meeting. ARRTC ARRTC28-10 ARRTC commended ERA on the quality and depth of work being done on closure activities at Ranger and the high quality of

information presented this meeting. ARRTC

ARRTC28-11 ARRTC requested that SSD provide a presentation on ERICA and the ARPANSA approach on non-human biota to next meeting. Mr Hughes ARRTC28-12 ARRTC agreed there should be a new separate KKN addressing radiation impacts on non-human biota. ARRTC ARRTC28-13 ARRTC requested a presentation be provided to next meeting outlining the conceptual framework for closure at Ranger (covering

the decommissioning, post-rehabilitation, and long-term post rehabilitation phases). Mr Hughes; Dr Sinclair

ARRTC28-14 Prof Boon to circulate to members an overview of the use of conceptual models in ecological rehabilitation. Prof Boon

ARRTC28-15 ARRTC agreed that the ERA proposed approach of using existing data is sound, but that further data should be collected so that the derived trigger values can be reviewed and refined in the future.

Dr Sinclair

ARRTC28-16 ARRTC commended ERA on the quality of current groundwater modelling work and the good progress to date in implementing the Weaver report recommendations.

ARRTC

ARRTC28-17 ARRTC requested that Dr Smith provide a presentation to next meeting on the integration of Aboriginal Traditional Knowledge (and expectations) into the closure planning process.

Dr Smith

ARRTC28-18 ARRTC agreed that ERA and SSD should undertake further work as part of the proposed risk assessment process to draft a risk based framework for prioritising the KKNs associated with the decommissioning and rehabilitation phases at the Ranger mine. ARRTC agreed members will be involved where possible in person by or email/teleconf.

Dr Sinclair, Mr Hughes

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ARRTC28-19 ARRTC agreed to look at the feasibility of holding a one day workshop in Canberra in September 2012 to enable members to review and comment on the draft risk framework and revised KKNs.

Secretariat

ARRTC28-20 ARRTC agreed that, consistent with the approach agreed last meeting, the draft revised KKNs would be reviewed at the November 2012 meeting on a by exception basis.

ARRTC

ARRTC28-21 ARRTC noted the Secretariat will finalise the draft ARRTC Terms of Appointment form and circulate to members out-of-session. ARRTC ARRTC28-22 ARRTC agreed that members would advise the Secretariat of their availability for the last two weeks of September and November

2012. Secretariat