Lessons Learned from Extremity Exposure Event on July 24, 2009

Operated by Los Alamos National Security, LLC for the U.S. Department of Energy’s NNSA

U N C L A S S I F I E D Slide 1

Lessons Learned from Extremity Exposure Event on

July 24, 2009

C. John GrahamLANSCE ESH&Q Manager

2010 Accelerator Safety WorkshopLA-UR 10-05375


U N C L A S S I F I E D

LANSCE presently provides the US and international research communities a diverse set of premier facilities

Lujan Center• Materials science and

condensed matter research• Bio-science• Nuclear physics • A National BES user facility

WNR• Nuclear physics• Semiconductor irradiation

Proton Radiography• HE science, dynamic materials

science, hydrodynamics

Isotope Production Facility• Nuclear medicine and

research isotope production

Ultra-cold Neutron Facility• Fundamental nuclear

physics

Beam delivery to multiple facilities 6 mo/yr @ 24/7 with ~ 1200 user visits



Background

•73/74As sample produced at LANSCE IPF and processed at TA-48 chemistry hot cells

•For WNR experiment to measure the 74As(n,p) cross section at low incident neutron energies using the lead slowing-down spectrometer in the Blue Room•Sample material material dried onto titanium backing and covered with thin Ti window

•74As is a beta emitter•Dose rate of 2-5 R/hr was expected

Slide 3



What happened• Original plan was to mount sample in an ion chamber at WNR

within a glove box to contain any contamination— RWP prepared with 5 R/hr dose rate limit; glove box expected

to mitigate beta hazard• TA-48 dose rate readings of 500 mR/hr and 30 R/hr

communicated to C-NR researcher at TA-53— Conversation was about ability to ship to TA-53— TA-48 RCT left voice mail for RP-1 at TA-53; no dose rate

detail • Sample received at MPF-541 trailer by C-NR researcher and

surveyed by day shift RCT— No contamination detected on inside of shipping container

(lead pig)• Survey tag from TA-48 indicated 500K dpm contamination

— External dose rate at 30 cm was 5 R/hr β+γ (1 R/hr γ) Slide 4



What happened RP-1 did not perform shallow (beta) dose calculation • RCT had only performed calculation for beam line components,

not for experiment sample receipt (former is common, latter is not)• Assumption of glove box use and further HP review

Extremity dosimetry not required by RWP• Assumed use of glovebox• Workers were wearing EPDs

Researcher and RCTs discussed dose rate readings and sample mounting• Researcher thought RP-1 knew that sample was to be mounted

outside glove box in WNR Blue Room entrance maze

Research team broke for dinnerSlide 5



What happened

RCT shift change; new RCT not aware of TA-48 dose rate measurements or significant beta component

Prejob meeting held• Researchers discussed rationale for mounting sample outside of

glove box with new RCT — No contamination found in receipt survey; less time for sample

mounting (ALARA)— RCT agreed, though change was outside of RWP

Sample transferred in pig from MPF-541 to Blue Room entrance hallway• Sample not re-surveyed outside of pig; new RCT thought previous

surveys were adequate

Slide 6



What happened

Slide 7

C-NR researcher and

LANSCE-NS researcher mounted sample in the ion chamber • Used tweezers but fingers

were needed to push sample into place

• RCT performed dose rate surveys (4 R/hr @ 30 cm; 115 mR/hr behind work area shielding)

• RCT measured 30 R/hr dose rate as ion chamber assembly was being completed

spacers cover

target source



What happened

•Work paused•Situation safed by placing cover on ion chamber•RP-1 HP consulted and agreed that completing assembly and installing sample in LSDS ensured a safe configuration

•Concern reported to TA-53 management 1 week later

Slide 8



What went wrong? Some things were done right, e.g. pauses in work, considering

ALARA, safeing the situation Imprecise communications• Generic IWD for LSDS but no IWD for this sample

— Experiment screening by LANSCE-NS was “low hazard” based on early information that sample mounting would be done at TA-48

• Work plan changed without adequate communication between research team and RP-1; RWP work description did not reflect the actual work; led to inconsistent understanding of hazards and insufficient controls

• TA-48 RCT left voice mail for TA-53 RP-1• Informal RCT shift turnover

RP-1 did not recognize need for a shallow dose calculation• Infrequent/unfamiliar activity

Slide 9



What went wrong? Improper assumptions and decision making• Sample assumed not significantly contaminated based on indirect

surveys of shipping container—reinforced decision to not use glove box

• RCT coming on shift assumed previous surveys were adequate• RCT concurred with working outside RWP• Hands-on work with sample continued without resolving discrepant

dose readings at TA-48

Slide 10



Consequences

Two persons at TA-53 received extremity doses of 26 and 19 rem, respectively• Based on dose reconstruction by RP• Below the DOE limit of 50 rem but

unplanned and unmonitored (no extremity dosimeters)

ORPS reportable category 2, PAAA noncompliance report DOE enforcement action and civil penalty

possible One of several incidents related to

R&D work control at the Lab

Slide 11



Lessons learned

ISM core function 1 (define work) is pivotal to identification of hazards and appropriate controls.

Unique or first-time hazardous work involving multiple organizations and disciplines requires teamwork, critical thinking, professional expertise, and rigor in communication and work control.

Follow work control documents. Changes (including inconsistent hazard information or real-time indicators) that affect hazard levels, controls, or assumptions about work execution warrant a pause, re-evaluation, and appropriate change control.

Slide 12



Lessons learned

Criteria for minor field changes to RWPs vs. major changes that require reauthorization of the work must be communicated and understood by personnel responsible for directing work activities.

Communication among SMEs and between SMEs and organizations performing work must be clear and frequent enough to ensure that the scope of work is well understood. SMEs should be engaged to help resolve inconsistent hazard information.

Slide 13



Lessons learned Real-time information should be shared through direct

communication across facilities and organizations. Information transfer by documentation is not a substitute for direct interactive communication.

Use of the revised P&T Form 2114 “Hazard Communication for Radioactive Material Shipments” will help ensure that those who unpack these materials, as well as support/oversight organizations, are informed of the nature of the packaging and associated hazards.

Slide 14



Lessons learned

When interdependent work processes take place in multiple facilities or organizations, work control documents should be coordinated or crosschecked to ensure consistency and comprehensiveness.

SMEs must be provided with tools to enable critical thinking with respect to hazards that are expected but not routinely encountered.

Complex or high hazard activities should be given priority for scheduling during normal working hours when management and support resources are available.

Slide 15

Lessons Learned from Extremity Exposure Event on July 24, 2009

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