NUREG-1555NUREG-1555NUREG-1555NUREG-1555

U.S. NUCLEAR REGULATORY COMMISSIONU.S. NUCLEAR REGULATORY COMMISSIONU.S. NUCLEAR REGULATORY COMMISSIONU.S. NUCLEAR REGULATORY COMMISSION

ENVIRONMENTALENVIRONMENTALENVIRONMENTALENVIRONMENTALSTANDARDSTANDARDSTANDARDSTANDARD

REVIEW PLANREVIEW PLANREVIEW PLANREVIEW PLANOFFICE OF NUCLEAR REACTOR REGULATIONOFFICE OF NUCLEAR REACTOR REGULATIONOFFICE OF NUCLEAR REACTOR REGULATIONOFFICE OF NUCLEAR REACTOR REGULATION

October 1999 5.3.3.2-1 NUREG-1555

USNRC ENVIRONMENTAL STANDARD REVIEW PLANEnvironmental standard review plans are prepared for the guidance of the Office of Nuclear ReactorEnvironmental standard review plans are prepared for the guidance of the Office of Nuclear ReactorEnvironmental standard review plans are prepared for the guidance of the Office of Nuclear ReactorEnvironmental standard review plans are prepared for the guidance of the Office of Nuclear ReactorRegulation staff responsible for environmental reviews for nuclear power plants. These documentsRegulation staff responsible for environmental reviews for nuclear power plants. These documentsRegulation staff responsible for environmental reviews for nuclear power plants. These documentsRegulation staff responsible for environmental reviews for nuclear power plants. These documentsare made available to the public as part of the Commission's policy to inform the nuclear industry andare made available to the public as part of the Commission's policy to inform the nuclear industry andare made available to the public as part of the Commission's policy to inform the nuclear industry andare made available to the public as part of the Commission's policy to inform the nuclear industry andthe general public of regulatory procedures and policies. Environmental standard review plans arethe general public of regulatory procedures and policies. Environmental standard review plans arethe general public of regulatory procedures and policies. Environmental standard review plans arethe general public of regulatory procedures and policies. Environmental standard review plans arenot substitutes for regulatory guides or the Commission's regulations and compliance with them isnot substitutes for regulatory guides or the Commission's regulations and compliance with them isnot substitutes for regulatory guides or the Commission's regulations and compliance with them isnot substitutes for regulatory guides or the Commission's regulations and compliance with them isnot required. The environmental standard review plans are keyed to Preparation of Environmentalnot required. The environmental standard review plans are keyed to Preparation of Environmentalnot required. The environmental standard review plans are keyed to Preparation of Environmentalnot required. The environmental standard review plans are keyed to Preparation of EnvironmentalReports for Nuclear Power Stations. Reports for Nuclear Power Stations. Reports for Nuclear Power Stations. Reports for Nuclear Power Stations.

Published environmental standard review plans will be revised periodically, as appropriate, toPublished environmental standard review plans will be revised periodically, as appropriate, toPublished environmental standard review plans will be revised periodically, as appropriate, toPublished environmental standard review plans will be revised periodically, as appropriate, toaccommodate comments and to reflect new information and experience.accommodate comments and to reflect new information and experience.accommodate comments and to reflect new information and experience.accommodate comments and to reflect new information and experience.

Comments and suggestions for improvement will be considered and should be sent to the U.S.Comments and suggestions for improvement will be considered and should be sent to the U.S.Comments and suggestions for improvement will be considered and should be sent to the U.S.Comments and suggestions for improvement will be considered and should be sent to the U.S.Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, Washington, D.C. 20555-Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, Washington, D.C. 20555-Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, Washington, D.C. 20555-Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, Washington, D.C. 20555-0001.0001.0001.0001.

5.3.3.2 TERRESTRIAL ECOSYSTEMS

REVIEW RESPONSIBILITIES

Primary—Appendix B

Secondary—Appendix B

I. AREAS OF REVIEW

This environmental standard review plan (ESRP) directs the staff’s identification and evaluation ofimpacts to terrestrial ecosystems induced by the operation of heat dissipation systems, especially coolingtowers and cooling ponds. The scope of the review directed by this plan will be limited to considerationof the operational aspects of heat dissipation systems in sufficient detail to form a basis for assessingpotential operational impacts.

Review Interfaces

The reviewer for this ESRP should obtain input from or provide input to reviewers for the followingESRPs, as indicated:

` ESRP 2.4.1. Obtain descriptive material on the terrestrial ecology of the site and vicinity to supportthe analyses made in ESRP 5.3.3.2.

` ESRP 3.4.2. Obtain specific information about the cooling system necessary to assess impacts to theterrestrial environment.

` ESRP 5.3.3.1. Obtain information about heat dissipation to the atmosphere necessary to determineimpacts to the terrestrial environment.

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` ESRP 5.10. Provide a list of measures and controls to limit adverse impacts to terrestrial biota thatare to be evaluated in regard to the licensing process and a list of applicant commitments to limitthese impacts.

` ESRP 6.5.1. If potential adverse impacts due to heat-dissipation are predicted, then providepreoperational baseline monitoring program elements.

` ESRP 9.4.1. Provide a list of adverse environmental impacts that could be mitigated or avoidedthrough use of alternative heat dissipation system designs or operational procedures, and assist indetermining appropriate alternatives.

` ESRP 10.1. Provide a summary of the unavoidable impacts to terrestrial ecosystems that arepredicted to occur as a result of operation of heat-dissipation systems.

` ESRP 10.2. Provide a summary of irreversible and irretrievable commitments of terrestrial biota thatare predicted to occur as a result of the operation of heat-dissipation systems.

Data and Information Needs

The type of data and information needed will be affected by site- and station-specific factors, and thedegree of detail should be modified according to the anticipated magnitude of the potential impacts. Thefollowing data or information should be obtained:

` concentration and chemical composition of dissolved and suspended solids in cooling tower basins orspray canals on a seasonal basis (from ESRP 3.4.2)

` isopleths of deposition at ground levels on a seasonal basis. Isopleths should extend to values at leastas low as 1 kg/ha/mo (from the environmental report [ER] and ESRP 5.3.3.1).

` a list and description of the “important” terrestrial species and habitats that may be affected by theheat-dissipation system (from ESRP 2.4.1)

` descriptions of natural and managed plant communities on the site and within offsite isopleths above20 kg/ha/yr (from ESRPs 2.4.1, 5.3.3.1, and the site visit)

` annual precipitation and its dissolved solid concentration within the drift field (from the ER)

` prediction of increased frequency and distribution of fog and icing (from ESRP 5.3.3.1)

` shoreline vegetation expected to develop along the shore of new cooling lakes and ponds (from theER and consultation with Federal, State, and local agencies)

` proposed other uses of cooling ponds and reservoirs (from the ER).

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II. ACCEPTANCE CRITERIA

Acceptance criteria for the review of impacts on terrestrial ecosystems from the heat dissipation systemare based on the relevant requirements of the following:

` 10 CFR 51.45 with respect to ERs and the analysis of potential impacts contained therein

` 10 CFR 51.75 with respect to analysis of impacts on the terrestrial environment affected by theissuance of a construction permit

` 10 CFR 52, Subpart A, with respect to analysis of impacts on the terrestrial environment affected bythe issuance of an early site permit

` 10 CFR 51.95 with respect to the preparation of supplemental environmental impact statements(EISs) in support of the issuance of an operating license

` Endangered Species Act of 1973, as amended, with respect to identifying threatened or endangeredspecies and critical habitats and formal or informal consultation with the U.S. Fish and WildlifeService and/or National Marine Fisheries Service

` Fish and Wildlife Coordination Act of 1958 with respect to consideration of fish and wildliferesources and the planning of development projects that affect water resources

Regulatory guidelines and specific criteria to meet the regulations and identified above are as follows:

` Regulatory Guide 4.2, Rev. 2, Preparation of Environmental Reports for Nuclear Power Stations(NRC 1976), contains guidance for the preparation of ERs. With respect to the heat-dissipationsystem, it specifies that detailed descriptions of the expected effects of the system on the localenvironment with respect to fog, icing, precipitation modifications, humidity changes, cooling-towerblowdown and drift, and noise should be included in the ER. The reviewer should ensure that theappropriate data and analyses are provided in the ER.

` Regulatory Guide 4.7, Rev. 2, General Site Suitability for Nuclear Power Stations (NRC 1998),contains guidance on factors that should be considered in the site-selection process. In specificregard to cooling-tower drift, this guide states “The potential loss of important terrestrial species andother resources should be considered.”

` Regulatory Guide 4.11, Rev. 1, Terrestrial Environmental Studies for Nuclear Power Stations (NRC1977), contains technical information for the design and execution of terrestrial environmentalstudies, the results of which may be appropriate for inclusion in the applicant’s ER. The reviewershould ensure that the appropriate results concerning potential effects of the heat-dissipation systemon the terrestrial environment are included in the ER.

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Technical Rationale

The technical rationale for evaluating the applicant’s impacts from heat-dissipation systems to terrestrialecosystems is discussed in the following paragraph:

The EIS needs to include the results of an analysis that considers the environmental effects of theproposed heat dissipation system and the alternatives available for reducing or avoiding adverseenvironmental effects. Any environmental benefits that may result from the operation of the heat dissipation system should also be included. Following the acceptance criteria listed above will helpensure that the environmental impacts of the proposed heat-dissipation system are considered withrespect to matters covered by such standards and requirements.

III. REVIEW PROCEDURES

The depth and extent of the input to the EIS will be governed by the environmental characteristics of theterrestrial ecology that could be affected by operation of the stationGs heat dissipation systems and by themagnitude of the expected impacts to the terrestrial environment.

The most apparent effects of heat dissipation systems on terrestrial ecosystems are those associated withcooling-tower or spray pond operation. These include the effects of vapor plumes, icing, and salt drift onthe terrestrial ecosystems. The potential for bird collision with cooling towers should be addressed bythe reviewer for ESRP 4.3.1. To date, at stations using once through cooling systems, no adverse impactsto terrestrial ecosystems have occurred that require mitigating actions. In circumstances where oncethrough cooling is proposed, the analysis may terminate without further consideration unless unusualenvironmental circumstances make more analysis necessary.

(1) Consider the impacts of drift deposition on plants.

` Drift deposition has the potential for adversely affecting plants, but the tolerance levels of nativeplants, ornamentals, and crops are not known with precision.

` General guidelines for predicting effects of drift deposition on plants suggest that many specieshave thresholds for visible leaf damage in the range of 10 to 20 kg/ha/mo of NaCl deposited onleaves during the growing season.

` These effects can be altered by the frequency of rainfall, humidity, type of salt, and sensitivity ofspecies.

` Use maps of the site and vicinity showing drift isopleths that were produced by recognized drift-dispersion models to define areas of possible botanical injury.

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` Use an order-of-magnitude approach, as follows, to analyze operational impacts from salt drift:

- Deposition of salt drift (NaCl) at rates of 1 to 2 kg/ha/mo is generally not damaging to plants.

- Deposition rates approaching or exceeding 10 kg/ha/mo in any month during the growingseason could cause leaf damage in many species.

- Deposition rates of hundreds or thousands of kg/ha/yr could cause damage sufficient tosuggest the need for changes of tower-basin salinities or a reevaluation of tower design,depending on the amount of land impacted and the uniqueness of the terrestrial ecosystemsexpected to be exposed to drift deposition.

(2) Consider the detrimental effects increased fogging could have on local vegetation if the increase inhumidity induces an increase in fungal or other phytopathological infections. Increased icing cancause physical damage to vegetation due to increased structural pressure on tree branches or bydamaging fruit or leaf buds.

` Use an order of magnitude approach as follows to analyze operational impacts from fog or ice:

- Fogging or icing of vegetation on the order of a few hours per year is generally not severe.

- Fogging or icing on the order of tens of hours per year may cause detectable damage tovegetation.

- Fogging or icing occurring for hundreds of hours per year could be severe enough to suggestthe need for design changes, depending on the amount of land impacted and the uniquenessof the terrestrial ecosystems expected to be exposed to drift deposition.

` Consider soil salinization:

- The risk from this source is generally considered to be low.

- In arid areas (deserts), salts could accumulate in soils over long time intervals and causedamage.

(3) Consider the impact to terrestrial biota when new shoreline habitats are created along ponds andreservoirs built for cooling purposes. Riparian tree/shrub communities that form around these newponds or reservoirs may attract “important” species.

If endangered or threatened species could be affected, agency level formal or informal consultationwith the U.S. Fish and Wildlife Service under Section 7 of the Endangered Species Act is required.

IV. EVALUATION FINDINGS

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Input to the EIS should accomplish the following objectives: (1) public disclosure of any expectedimpact to the terrestrial ecosystem as a result of the operation of the heat dissipation system,(2) presentation of the basis of staff analysis of the project, and (3) presentation of staff conclusions,evaluations, and conditions regarding terrestrial ecosystems. These conclusions should include

` a list of adverse impacts of cooling-system heat dissipation to terrestrial ecosystems

` a list of the impacts for which there are measures or controls to limit adverse impacts and associatedmeasures and controls

` the applicant’s commitments to limit these impacts

` the staff’s evaluation of the adequacy of the applicant’s measures and controls to limit adverseimpacts.

This information should be summarized by the reviewer for ESRP 5.10.

Evaluation of impacts should result in one of the following conclusions:

` The impact is minor, and mitigation is not warranted. If the degree of impact falls into the first ordercategory (a few hours of icing or fogging each year or a few kilograms of salt drift per hectare peryear), the reviewer may conclude that these impacts are not of sufficient magnitude to warrant furtherevaluation.

` The impact is adverse, but can be mitigated by design and procedure modifications. If the degree ofimpact falls within the second-order category (a few tens of hours per year increase in fog or ice or afew tens of kilograms of salt drift deposition per hectare per year), the reviewer may conclude thatthe effects are adverse and that mitigating actions should be considered. For these cases, thereviewer should consult with the Environmental Project Manager (EPM) and the reviewer forESRP 9.4.1 for verification that the modifications are practical and will lead to an improvement inthe benefit-cost balance. The reviewer should prepare a list of verified modifications and measuresand controls to limit the corresponding impact. These lists should be given to the reviewer for ESRP5.10.

` The impact is adverse and is of such magnitude that it should be avoided, if it cannot be mitigated. Ifthe degree of expected impacts falls within the third order category (hundreds of hours of increase infog and ice or hundreds of kilograms of salt drift per hectare per year), the reviewer may concludethat the impacts of operation are sufficiently adverse that consideration of alternative designs orlocations to avoid the impact is warranted. When impacts of this nature are identified, the reviewershould inform the EPM and the reviewer for ESRP 9.4.1 that an analysis and evaluation of alterna-tive designs or procedures is needed. The reviewer should participate in any such analysis andevaluation of alternatives that would avoid the impact and that could be considered practical. If no

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such alternatives can be identified, the reviewer should provide this conclusion to the reviewer forESRP 10.1.

V. IMPLEMENTATION

The method described herein will be used by the staff in evaluating conformance with the Commission’sregulations, except in those cases in which the applicant proposes an acceptable alternative forcomplying with specified portions of the regulations.

VI. REFERENCES

10 CFR 51.45, “Environmental report.”

10 CFR 51.75, “Draft environmental impact statement—construction permit.”

10 CFR 51.95, “Supplement to final environmental impact statement.”

10 CFR 52, Subpart A, “Early Site Permits.”

Endangered Species Act, as amended, 16 USC 1531 et seq.

Fish and Wildlife Coordination Act Amendment, 16 USC 661 et seq.

U.S. Nuclear Regulatory Commission (NRC). 1976. Preparation of Environmental Reports for NuclearPower Stations. Regulatory Guide 4.2, Rev. 2, Washington, D. C.

U.S. Nuclear Regulatory Commission (NRC). 1977. Terrestrial Environmental Studies for NuclearPower Stations. Regulatory Guide 4.11, Rev. 1, Washington, D. C.

U.S. Nuclear Regulatory Commission (NRC). 1998. General Site Suitability for Nuclear PowerStations. Regulatory Guide 4.7, Rev. 2, Washington, D. C.

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ENVIRONMENTAL IMPACTS OF OPERATION

during the licensing of the facility or themechanisms of NPDES permitting andassociated 316(a) and (b) determinations.They either were found acceptable ormitigated. For some plants with once­through cooling systems, the large volumesof water withdrawn, heated, and dischargedback to the receiving water may causeadverse effects to fish and shellfishpopulations during the license renewalterm. Because impacts of entrainment offish and shellfish, impingement, andthermal discharge effects could be small,moderate, or large, depending on the plant,these are Category 2 issues for plants withonce-through cooling systems. These issueswill need to be analyzed in thesupplemental NEPA document at the timeof license renewal.

4.3 COOLING TOwERS

This section introduces cooling towers andtheir emissions (Section 4.3.1) and thenevaluates the impacts of the emissions onsurface water and groundwater(Section 4.3.2), aquatic ecology(Section 4.3.3), agricultural crops(Section 4.3.4), terrestrial ecology(Section 4.3.5, which also includes birdcollisions with cooling towers), and humanhealth (Section 4.3.6). Impacts of cooling­tower noise are also addressed(Section 4.3.7). Each section that evaluatesimpacts (Sections 4.3.2-4.3.7) provides aconclusion that defines the significance ofthe impacts. These conclusions are basedon reviews of cooling-tower data availablefor towers at specific nuclear plants as wellas for other cooling towers (e.g., those atcoal-fired plants).

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4.3.1 Introduction

Mechanical- and natural-draft wet coolingtowers transfer waste heat to theatmosphere primarily by evaporating water.Natural-draft towers are generally up to160 m (520 ft) in height, whereasmechanical-draft towers are generally lessthan 30 m (100 ft) tall (Roffman andVan Vleck 1974). Because of the largecooling capacity of natural-draft towers,only one such tower is required for eachreactor unit; but two or more mechanical­draft towers are required for equivalentcooling.

Most of the water lost from a coolingtower escapes to the atmosphere as watervapor in the exhaust flow. About10 percent of the vapor recondenses afterrelease, forming the visible part of theplume leaving the tower (Golay et al.1986). Drift droplets of cooling water arealso entrained in the air stream inside thetower and escape directly into theatmosphere. A particulate solid driftmaterial remains after droplet evaporation.The drift contains varying amounts of salts,biocides, and microorganisms.

Natural-draft towers release drift andmoisture high into the atmosphere wherethey are dispersed over long distances.Local impacts are more likely to occur withmechanical-draft towers because the plumeis not dispersed over as great an area. Thevisible moisture plume from a natural-draftcooling tower may be 20 to 30 percentlonger than that from comparablemechanical-draft towers (Roffman and VanVleck 1974). Icing of vegetation and roads:can occur near mechanical draft towerswhen fog is present and temperatures arebelow freezing. Much of the drifteventually deposits on the earth. Theatmospheric transport of drift and the

amount of deposition to the earth has beenestimated for most nuclear plants throughthe use of computer models. Actualmeasurements of drift deposition havebeen collected at only a few nuclear plants.These measurements indicate that, beyondabout 1.5 km (1 mile) from nuclear plantcooling towers, salt deposition is notsignificantly above natural backgroundlevels.

4.3.2 Surface Water Quality and Use

Sections 4.3.2 and 4.3.3 review the past andongoing impacts on aquatic resourcescaused by the operation of nuclear powerplants with cooling towers. Any ongoingimpacts will probably continue into thelicense renewal term because the coolingsystem design and operation will notchange as a result of license renewal.Judgments about the significance of theseissues during the license renewal terms arebased on published information, agencyconsultation, and information provided bythe utilities (Appendix F) applicable toevery nuclear power plant in the UnitedStates. The conclusions drawn inSections 4.3.2 and 4.3.3 apply to all nuclearpower plants with cooling towers.

4.3.2.1 Water Use

Two factors may cause water-use andwater-availability issues to becomeimportant for some nuclear power plantsthat use cooling towers. First, the relativelysmall rates of cooling water withdrawal anddischarge allowed some power plants withcooling towers to be located on smallbodies of water that are susceptible todroughts or competing water uses. Second.closed-cycle cooling systems evaporatecooling water, and consumptive waterlosses may represent a substantialproportion of the flows in small rivers.

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Loss of a substantial portion of flow from asmall stream as a result of evaporativelosses from a cooling tower will reduce theamount of habitat for fish and aquaticinvertebrates. Off-stream water uses, suchas power plant consumption, must beregulated to ensure that important in­stream uses, such as habitat for aquaticorganisms, boating, angling, and wasteassimilation, are not compromised.

Consumptive water use can adverselyimpact riparian vegetation and associatedanimal communities by reducing theamount of water in the stream that isavailable for plant growth, maintenance,and reproduction. Riparian vegetation isdefined as streamside vegetation that isstructurally and floristically distinct fromadjacent upland plant communities (Taylor1982). Riparian vegetation has importantecological functions; and its importance asa resource has been widely recognized andreviewed (e.g., Brinson et al. 1981; Johnsonet al, 1985). Briefly, riparian vegetationstabilizes stream channels and floodplains.It influences biogeochemical cycles, watertemperature and quality, and the durationand magnitude of flooding. Riparianvegetation also provides diverse cover,food, water, reproductive habitat, andmigration corridors for many aquatic andterrestrial animals. As a result, riparianzones often support a wide variety andhigh density of wildlife (deer, smallmammals, songbirds, raptors, reptiles, andamphibians) , especially in arid or urbanizedareas. Riparian vegetation may beadversely affected by dewatering in anumber of ways (Taylor 1982), includingdecreases in the width of the ripariancorridor, changes in species and communitydiversity, increased susceptibility toflooding, changes in tree canopy cover,lower tree basal area, and lower seedlingdensities. Impacts to wildlife occur as a

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direct or indirect result of degradation ofriparian habitats. Such dewatering effectsare most apparent in the arid and semi-aridWest; in the eastern United States,dewatering effects generally involve moresubtle changes in community compositionbecause of the higher precipitation,humidity, and soil moisture and the lowerwater stress conditions that prevail.

Limerick Generating Station, located onthe Schuylkill River at Pottstown,Pennsylvania, is an example of a plant witha closed-cycle cooling system that is subjectto water availability constraints because ofin-stream-flow requirements in a smallerriver, controversy over water use related tointerbasin transfer, competing water uses,and water-related agreements betweenutilities. Aquatic resource issues identifiedinclude (1) water quality and low-flowproblems in the Schuylkill River; (2) wateravailability conflicts with downstream waterusers; (3) increased in-stream flowrequirements, particularly with respect tocontinuing efforts to improve the waterquality of the Schuylkill River and toreintroduce American shad into the river;and (4) concerns over saltwater movementupstream in the Delaware River as theresult of upstream water use (Margaret A.Reilly, letter to G. F. Cada, ORNL, OakRidge, Tennessee May 24, 1990;D. T. Guise, letter to G. F. Cada, ORNL,Oak Ridge, Tennessee, July 3, 1990).

Limerick is in one of the fastest growingregions in Pennsylvania, which isexperiencing heavy residential developmentand water demands for domestic, existingindustrial, and developing industrial uses(Joseph Hoffman, letter to V. R. Tolbert,ORNL, Oak Ridge, Tennessee, August 27,1990). Limerick is permitted to withdrawup to 13 percent of the minimum flow ofthe Schuylkill River and a major portion of

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the flow of Perkiomen Creek for coolingtower makeup. Only 5 percent of the1.8-2.0 m3/s (65-70 £13/S) withdrawn fromthe Schuylkill River when the now isgreater than 15 m3/s (530 ft3/s) is returnedto the river. This loss of in-stream flow isviewed as a significant contribution to thewater quality and low-flow problems in theSchuylkill River (Dennis T. Guise, letter toG. F. Cada, ORNL, Oak Ridge,Tennessee, July 3, 1990). This water-useissue may be exacerbated as efforts toreintroduce the American shad into theSchuylkill River continue. In addition tothe water use from the Schuylkill River,2 m3/s (71 ft3/s) of water is diverted fromthe Delaware River to the East Branch ofPerkiomen Creek via the Point PleasantDiversion at a rate of 2 m3/s (71 fe/s); thisinterbasin transfer affects the achievementof the 85 m3/s (3000 ft3/s) minimum flowobjective in the Delaware River atTrenton. The effects of the diversion arebeing debated through an NPDES permitappeal before the PennsylvaniaEnvironmental Hearing Board (Dennis T.Guise, letter to G. F. Cada, ORNL, OakRidge, Tennessee, July 3, 1990).

The Palo Verde NGS offers anotherexample of competing water uses that mayaffect continued operation of nuclearfacilities that use cooling towers. PaloVerde currently uses treated effluent from,the cities of Phoenix and Tolleson forcooling tower makeup water. Theblowdown from the cooling towersdischarges to on-site lined evaporationponds [Arizona Public Service Companyresponse to NUMARC survey (NUMARC1990)]. In the absence of the power plant,part of the municipal effluent would beused for commercial purposes and theremainder discharged to the Gila River,where it would be used for groundwaterrecharge, irrigation, and support of riparian

habitat (Jack Bale, letter to G. F. Cada,ORNL, Oak Ridge, Tennessee, May 31,1990). According to the Arizona Game andFish Department (Donald Turner, ArizonaGame and Fish Department letter to G. F.Cada, ORNL, Oak Ridge, Tennessee,June 29, 1990), if Palo Verde uses all of itsallocation, the flow from the Gila Riverdownstream to Gillespie Dam will bereduced, the water tables will dropsignificantly, and aquatic habitat andriparian vegetation will be destroyed.Sixty-nine percent of the water flowing inthe Gila and Salt rivers downstream fromthe Ninety-First Avenue treatment plant isdischarged by the treatment plant. Most ifnot all of the water produced by thetreatment plant is committed to PaloVerde. When all three units of the plantwere operating, flow in the river wassignificantly reduced, pools and pondsdried up, and numerous fish die-offsoccurred (Donald Turner, Arizona Gameand Fish Department, letter to G. F. Cada,ORNL, Oak Ridge, Tennessee,June 29, 1990).

Nuclear facilities on small bodies of watermay experience water-use constraintsrelated to availability. For example, duringtemporary drought periods, power plantswith cooling towers may have to curtailoperations if evaporative water lossesexceed the capacity of small, multiple-usesource bodies of water. Byron Station inIllinois withdraws water from the RockRiver to supply natural-draft coolingtowers. By agreement with the IllinoisDepartment of Conservation, thewithdrawal for makeup is limited to 3.5m3js (125 ft3jS) and net water consumptionis limited to no more than 9 percent of theflow below 19 m3js (679 ft3jS)[Commonwealth Edison Company responseto NUMARC survey (NUMARC 1990)].Duane Arnold Energy Center on the

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Cedar River in Iowa uses mechanical-draftcooling towers for condenser cooling andcould also experience water availabilityconstraints. The state of Iowa Departmentof Natural Resources currently has nowater-use concerns with operation ofDuane Arnold (Larry J. Wilson, letter toG. F. Cada, ORNL, Oak Ridge,Tennessee, May 22, 1990); however, theplant may possibly experience futureconstraints on the availability of water forconsumptive use, because the surface waterwithdrawals within the state are projectedto increase by 19 percent from 1985 to2005 (Thamke 1990). Within Linn County,where Duane Arnold is located, water useis also projected to increase (BrianTormee, telephone interview withV. R. Tolbert, ORNL, Oak Ridge,Tennessee, September 4, 1990).

Consultations with regulatory andresources agencies indicate that water useconflicts are already a concern at twoclosed-cycle nuclear power plants(Limerick and Palo Verde) and may be aproblem in the future at Byron Station andthe Duane Arnold Energy Center. Becausewater use conflicts may be small ormoderate during the license renewalperiod, this is a Category 2 issue fornuclear plants with closed-cycle coolingsystems. Related to this, the effects ofconsumptive water use on in-stream andriparian communities could also be small ormoderate, depending on the plant, and isalso a Category 2 issue.

4.3.2.2 Water Quality

Although cooling towers are considered tobe closed-cycle cooling systems,concentration of dissolved salts in themakeup water-which results fromevaporative water loss-requires thedischarge of a certain percentage of the

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mineral-rich stream (blowdown) and itsreplacement with fresh water (makeup).The quantities of blowdown are relativelysmall compared with the discharges fromonce-through systems, typically on theorder of 10 percent. Water quality impactscould occur from the elevatedtemperatures of the blowdown or from theconcentration and discharge of chemicalsadded to the recirculating cooling water (toprevent corrosion and biofouling, regulatepH, etc.), A unit of water may reside in thecooling circuit for 3 to 20 cycles beforebeing lost to evaporation or released in theblowdown stream (Coutant 1981). Theconcentration of total dissolved solids inthe cooling tower blowdown averages500 percent of that in the makeup water, aconcentration factor that can be toleratedby most freshwater biota(ORNLINUREGfTM-226). Dilution of thelow-volume blowdown by the receivingwater also reduces water quality impacts ofheat and contaminants discharged fromclosed-cycle cooling systems.

Because of strict regulation of chemicaldischarges from steam-electric power plants(e.g., EPA regulations per40 CFR Part 423), water treatment systemsfor cooling tower blowdown have beendeveloped. Many of these systemsrecapture chemical additives for recyclingin the cooling system (Coutant 1981). Asnoted in Section 4.2, all nuclear powerplants are required to obtain an NPDESpermit to discharge effluents. Thesepermits are renewed every 5 years by theregulatory agency, either EPA or, morecommonly, the state's water qualitypermitting agency. The periodic NPDESpermit renewals provide the opportunity torequire modification of power plantdischarges or to alter discharge monitoringin response to water quality concerns.Utility responses to the NUMARC survey

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, (Table F.2) indicate that such changes havebeen made during the plants' operation tocorrect water quality problems.

Impacts of cooling tower discharges areconsidered to be of small significance ifwater quality criteria (e.g., NPDESpermits) are not consistently violated. Inconsidering the effects of closed-cyclecooling systems on water quality, the staffevaluated the same issues that wereevaluated for open-cycle systems(Table 4.1): altered current patterns,altered salinity gradients, temperatureeffects on sediment transport capacity,altered thermal stratification of lakes,scouring from discharged cooling water,eutrophication, discharge of chlorine andother biocides, discharge of other chemicalcontaminants, and discharge of sanitarywastes. Based on review of literature andoperational monitoring reports,consultations with utilities and regulatoryagencies, and comments on the draft GElS,discharge of cooling tower effluents hasnot been a problem at existing nuclearplants. Although occasional violations ofNPDES permits have occurred at manyplants (e.g., minor spills), water qualityimpacts have been localized and temporary.Effects are considered to be of smallsignificance for all plants. Cumulativeimpacts to water quality would not beexpected because the small amounts ofchemicals released by these low-volumedischarges are readily dissipated in thereceiving waterbody. No change inoperation of the cooling system is expectedduring the license renewal term, so nochange in effects of cooling towersdischarges on receiving water quality isanticipated. Effects of cooling towerdischarges could be reduced by operatingadditional wastewater treatment systems, orby reducing the plant's generation rate.However, because the effects of cooling

tower discharges on water quality areconsidered to be impacts of smallsignificance and because the changes wouldbe costly, the staff does not consider theimplementation of these potentialmitigation measures to be warranted.Effects of cooling tower discharges onwater quality are all Category 1 issues.

4.3.3 Aquatic Ecology

Cooling towers have been suggested asmitigative measures to reduce known orpredicted entrainment and impingementlosses (see, for example, Barnthouse andVan Winkle 1988). The relatively smallvolumes of makeup and blowdown waterneeded for closed-cycle cooling systemsresult in concomitantly low entrainment,impingement, and discharge effects (seeSection 4.2.2 for a more completediscussion of these effects regarding once­through cooling systems). Studies of intakeand discharge effects of closed-cyclecooling systems have generally judged theimpacts to be insignificant (NUREG/0720;NUREG/CR-2337). None of the resourceagencies consulted for this GElS(Appendix F) expressed concerns aboutthe impacts of closed-cycle cooling towerson aquatic resources.

However, even low rates of entrainmentand impingement at a closed-cycle coolingsystem can be a concern when an unusuallyimportant resource is affected. Suchaquatic resources would include threatenedor endangered species or anadromous fishthat are undergoing restoration. Forexample, concern about potential impactsof the Washington Nuclear Project(WNP-2) on chinook salmon has beenraised by the Washington Department ofFisheries (Cynthia A. Wilson, WashingtonDepartment of Fisheries, letter to G. F.Cada, ORNL, Oak Ridge, Tennessee,

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ENVIRONMENTAL IMPACTS OF OPERATION

July 5, 1990). Although entrainment,impingement, and thermal discharges arenot believed to be a problem at WNP-2,the importance of the Columbia Riversalmon stocks are such that the resourceagency feels that monitoring shouldcontinue. Similarly, the Pennsylvania FishCommission has expressed concern aboutfuture entrainment and impingement ofAmerican shad by the Limerick GeneratingStation, the Susquehanna Steam ElectricStation, Three Mile Island Nuclear Station,and Peach Bottom Atomic Power Station(Dennis T. Guise, Pennsylvania FishCommission, letter to G. F. Cada, ORNL,Oak Ridge, Tennessee, July 3, 1990). In allcases, losses of American shad at thesepower plants are minimal or nonexistent,but periodic monitoring has beenrecommended to ensure that no futureproblems occur as the anadromous fishrestoration efforts continue.

It is unlikely that the small volumes ofwater withdrawn and discharged by closed-.cycle cooling systems would interfere with ;the future restoration of aquatic biota ortheir habitats. Effects of operation ofclosed-cycle cooling systems on aquaticorganisms are considered to be of smallsignificance if changes are localized andpopulations in the receiving waterbody arenot reduced. In considering the effects ofclosed-cycle cooling systems on aquaticecology, the staff evaluated the same issuesthat were evaluated for open-cycle systems(Table 4.1): impingement of fish andshellfish, entrainment of fish and shellfishearly life stages, entrainment ofphytoplankton and zooplankton, thermaldischarge effects, cold shock, effects onmovement and distribution of aquaticbiota, premature emergency of aquaticinsects, stimulation of nuisance organisms ,losses from predation, parasitism, anddisease, gas supersaturation of low

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ENVIRONMENTAL IMPAcrs OF OPERATION

dissolved oxygen in the discharge, andaccumulation of contaminants in sedimentsor biota. Based on reviews of literature andoperational monitoring reports,consultations with utilities and regulatoryagencies, and comments on the draft GElS,these potential effects have not beenshown to cause reductions in the aquaticpopulations near any existing nuclearpower plants. None of the regulatory andresource agencies expressed concernsabout the cumulative effects on aquaticresources of closed cycle cooling systemoperations at this time, although somerecommended continued monitoring inview of efforts to restore fish populations.Effects of all of these issues are consideredto be of small significance for all plants.No change in operation of the coolingsystem is expected during the licenserenewal term, so no change in effects ofcooling towers on aquatic biota isanticipated. Effects of entrainment,impingement, and discharges from closed­cycle cooling systems could be reduced byreducing the plant's generation rate, or byoperating additional wastewater treatmentsystems. However, because the effects ofcooling tower withdrawals and dischargeson aquatic organisms arc considered to beimpacts of small significance and becausethe changes would be costly, the staff doesnot consider the implementation of thesepotential mitigation measures to bewarranted. The effects of closed-cyclecooling system operation on aquatic biotaarc all Category 1 issues.

4.3.4 Agricultural Crops and OrnamentalVegetation

The issue addressed by this section is theextent to which the productivity ofagricultural crops near nuclear plants maybe reduced by exposure to salts or othereffects (e.g., icing, increased humidity)

NUREG-1437, Vol. 1 4-34

resulting from cooling-tower operation.The approach to evaluating this issue wasas follows: first, based on a literaturereview, potential impacts of salts in general(whether from cooling towers or othersources such as wind-blown salts nearseashores) are described according to therate of salt deposition to earth and therelative sensitivity of different types ofcrops (Section 4.3.4.1); then, the datagenerated by monitoring programs at arepresentative subset of specific nuclearplants were reviewed (Section 4.3.4.2). Thesubset includes 10 of the 11 nuclear powerplants with mechanical-draft coolingtowers. Mechanical-draft towers arc thefocus of this section because impacts ofdrift deposition and icing are more likely tooccur near these towers than at natural­draft towers. Drift from natural-drafttowers is released at greater heights,disperses more widely, and thereforedeposits on earth at lower rates or iconcentrations. Data were also found and 'reviewed for 8 of the 17 plants withnatural-draft cooling towers (Table 4.1).The coal-fired Chalk Point Plant was alsoincluded in the analysis because extensivemonitoring of cooling-tower-drift effectshas been conducted there and because thisplant uses brackish water for cooling andrepresents a case with comparatively highpotential for drift impacts from natural­draft towers. The only nuclear plant thathas a natural-draft tower and uses brackishwater for cooling is Hope Creek inNew Jersey. It is included among the plantsthat were reviewed.

The following standard of significance isapplied to the effects of cooling toweroperation on agricultural crops andornamental vegetation. The impact is ofsmall significance if under expectedoperational conditions measurableproductivity losses (either quantity or

quality of yield) do not occur foragricultural crops; and measurable damage(either visual or to plant function) doesnot occur for ornamental vegetation.

4.3.4.1 Overview of Impacts

4.3.4.1.1 Ambient Salts and Cooling-TowerDrift

Agricultural crops can be affected bychemical salts and biocides in cooling towerdrift and drift-induced or plume-inducedice formation. Increased fogging, cloudcover, and relative humidity resulting fromcooling-tower operation have littlepotential to affect crops, and adverseeffects have not been reported. Generally,drift from cooling towers using fresh waterhas low salt concentrations and, in the caseof mechanical draft towers, falls mostlywithin the immediate vicinity of the towers(ANLIES-53), representing little hazard tovegetation off-site. Typical amounts of saltor total dissolved solids in freshwaterenvironments are around 1000 ppm(ANLIES-53). In arid environments,competition for water resources can resultin the use of relatively low-quality or salinewater for cooling, and the potential fordrift-induced damage to surroundingvegetation may be greater (McBrayer andOakes 1982). For example, source waterfor cooling at Palo Verde in Arizona iswithdrawn from an onsite reservoircontaining treated sewage effluent ofrelatively high salinity. As a result, coolingtower basin water also had high salinitylevels including 10,000 to 26,000 ppm totaldissolved solids, 3,400 to 7,000 ppm cr,and 2,700 to 8,600 ppm Na+ (NUS-5241).High salt levels also occur at plants on thecoasts or coastal bays. Brackish coolingwater used by the Chalk Point coal-firedplant in Maryland contained 11,000 to26,000 ppm total soluble salts and 6,600 to

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ENVIRONMENTAL IMPACTS OF OPERA'nON

18,000 ppm CI- (Mulchi and Armbruster1983). Nuclear plants with cooling towersuse fresh water, except for the HopeCreek Plant in New Jersey, which usessaline water. At the Crystal River Plant,Florida, which currently uses brackishwater in once-through cooling, a helpercooling tower has been constructed to coolwater in a canal that receives dischargefrom five fossil and one nuclear units.

Talbot (1979) has concluded that adequateestimates of natural background levels ofatmospheric salt loading (naturallyoccurring drift) and rates of depositionthereof are not available for points remotefrom oceans. In field measurements at awet cooling tower, A. Backhaus et al.(1988) estimated that up to 60 percent ofthe chemical contents in the sample camefrom atmospheric aerosols and not from 'the tower. Therefore, observed depositionis not all drift from cooling towers (Talbot1979). Recent work (ORNLffM-11121)has quantified background aerosoldeposition for a dozen sites throughout thecountry, but deposition for most locationsremains poorly known.

Salts from cooling towers arc deposited onvegetation by (1) wind-driven impaction,(2) droplet and particulate fallout, and (3)rainfall (Talbot 1979; CONF-740302,1975b). In high-salt environments such as awindy seashore, impaction is usually themost important process , delivering 10 timesmore salt to vegetation than does fallout.Increasing wind speeds and saltconcentrations increase impaction, henceincreasing vegetation injury (Talbot 1979).In most humid environments, rainwater willwash off salts deposited on vegetation(ANL/ES-53), but exposure can besignificant during periods between rainfalls.

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ENVIRONMENTAL IMPACTS OF OPERATION

4.3.4.1.2 Effects of Salt Drift

Plants damaged by salt drift may haveacute symptoms, including necrotic ordiscolored tissue, stunted growth, ordeformities (Talbot 1979; Hoffman et a1.1987). Chronic effects are less obvious butmay include some degree of chlorosis andreduced growth (Talbot 1979) or increasedsusceptibility to disease and insect damage(Hosker and Lindberg 1982).

Climatic conditions affect plants' ability totolerate salt (Talbot 1979; Maas 1985). Thedegree of injury is related to the saltcontent in the leaves, but hot or dryweather conditions and water stress arecritical in inducing injury (most crops cantolerate greater salt stress during relativelycool and humid weather) (Maas 1985).

Among the factors that affect the plant'sfoliar accumulation of salt are physicalcharacteristics of the leaves (Maas 1985;CONF-740302, 1975d; Taylor 1980), typeand concentration of salt, ambienttemperature and humidity, and length oftime the leaf remains wet (Maas 1985).Because salt on foliage is apparentlyabsorbed from solution, high humidity,which retards evaporation, enhances saltuptake (CONF-740302, 1975d; McCuneet aL 1977; Talbot 1979; Grattan et aL1981). Because precipitation and dewaffect salt deposition, uptake, and resultantinjury, dose exposure is difficult to predict(Talbot 1979; Grattan et al. 1981; McCuneet a1. 1977; EPA-600/3-76-078).

Plant species and crop varieties varysignificantly in their tolerance to driftdeposition and to soil salinity (Talbot 1979;Maas 1985). In general, salt uptake, plantinjury, and reduction in crop yield havebeen shown to increase with increasinglevels of airborne salt or deposition and

NUREG·1437, Vol. 1 4-36

with time of exposure (CONF.740302,1975b; Mulchi and Armbruster 1981; Maas;Grattan et al.; EPA-600/3-76-078). Someplants, however, have shown a slightincrease in vegetative productivity [e.g.,tobacco at < 4 kglha (3.6 lb/acre) perweek (Mulchi and Armbruster 1983) andcotton at 8 kglha (7 lb/acre per week)(Hoffman et a1. 1987)]. Based onexperimental exposures, a yield reductionof 10 percent has been estimated fordeposition levels as low as 4.7 kglha(4.2 lb/acre) per week to corn, a speciessensitive to foliar salt injury (Mulchi andArmbruster 1981). Relationships betweenexperimental levels of salt deposition, foliarconcentrations of sodium and chloride, andcorn yield show that yield may be slightlyreduced even at rates as low as 2 kg/ha(1.81b/acre) per week (Mulchi andArmbruster 1981). Also, bush beans canhave reduced yield depending on the ageof plants, with older plants being mostsensitive (EPA-600/3-76-078). Depositionrates near nuclear-plant towers, accordingto available deposition data(Section 4.3.5.1.2), appear to be generallybelow the rates that would affect sensitiveagricultural crops.

Talbot (1979) tabulated salt depositionamounts known to induce acute toxicitysymptoms in vegetation (Table 4.2). Cornwas the most sensitive crop, showing injuryabove 1.8 kglha (1.6 lb/acre) per week; theleast sensitive was pinto beans, showinginjury above 253 kglha (226 lb/acre) perweek. Armbruster and Mulchi (1984)showed that foliar salt deposition of 3.2 to8.8 kg/ha (2.9 to 7.9 lb/acre) per weekincreased foliar chloride content anddamaged foliage of corn, with the higherdeposition reducing the yield of grain by asmuch as 11 percent. They found similarresults for soybeans, with bean yields

ENVIRONMENTAL IMPACfS OF OPERATION

Table 4.2 Estimates of salt-drift deposition rates estimated to cause acute injury tovegetation

Deposition above whichinjury is expected

Species (kg/ha/week)

Crops and ornamental plants

Zea mays (corn)Glycine hispida var York (soybean)Gossypium hirsutum (cotton)Medicago sativa (alfalfa)Forsythia intermedia var spectabilis

(forsythia)Phaseolus vulgaris varPinto

(pinto bean)Albizzia julibrissin rosea

(mimosa)Koelreutaria paniculata

(golden rain tree)

Native species

Comus florida(flowering dogwood)

Fraxinus americana(white ash)

Tsuga canadensis(Canadian hemlock)

Pinus strobus(white pine)

Quercus prinus(chestnut oak)

Robiniapseudoacacia(black locust)

Acer rubrum(red maple)

Hammamelis virginiana(witch hazel)

Source : Adapted from Talbot 1979 and Hoffman et at. 1987.Note: To convert kg/lJa to Ib/acre, multiply by 0.8924.

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1.827.288.0

15.7189.6

252.8

379.2

568.8

1.2 (in Maryland)47.4 (in New York)

1.3 (in Maryland)18.9 (in New York)9.4

189.6

379.2

379.2

474.0

1042.8

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ENVIRONMENTAL IMPACTS OF OPERATION

reduced by as much as 7 percent at thehighest deposition rate.

W. C. Hoffman et al. (1987) experimentallyexposed cotton and cantaloupe in the aridenvironment ncar Palo Verde to foliar saltdeposition rates of 8 to 415 kg/ha (7 to370 lb/acre) per year total salt and alfalfato depositions up to 829 kg/ha(740 Ib/acre) per year. They found foliarinjury in alfalfa only at the highestdeposition level but no injury tocantaloupe or cotton despite increases infoliar Na" and CI-. Yields of cantaloupeand alfalfa were not reduced, but 415 kg/ha(370 lb/acre) per year reduced colton bollproduction and seed cotton yield byapproximately 25 percent.

The burning quality of tobacco is known tobe adversely affected by elevated CI-.Experiments have shown that burningquality, or length of time the leaf will burn,is impaired by increasing experimentaldoses of salt deposition (Mulchi andArmbruster 1983). A 17 percent reductionin burning quality was estimated for a CI­deposition of 5 kg/ha (4.5 lb/acre) perweek, based on regression relationships ofdeposition, leaf chloride concentration, andleaf burn (Mulchi and Armbruster 1983).

Field studies of the effects of salt drifthave been conducted at the Turkey Pointplant and the coal-fired Chalk Point plant.Hindawi et al, (EPA-440/5-86-001)investigated field exposures of bean andcorn plants to saltwater drift from a testcooling tower and power spray module atthe Turkey Point plant. Salt concentrationsin tissues of bean and corn plants increasedwith time during three weeks of exposureand decreased exponentially with distancefrom the salt drift source. Some injury toleaves was visible at the site of greatestexposure.

NUREG-1437 , Vol. 1 4-38

The coal-fired Chalk Point plant has arelatively high potential impact fromnatural-draft cooling towers becausebrackish water is used for cooling. Otherthan the Hope Creek plant, all nuclearplants with natural-draft towers use freshwater for cooling. Deposition rates atChalk Point were measured at12 monitoring sites at distances of from1.6 km to 9.6 km (1 to 6 miles) from thetowers during their initial 5 years ofoperation (Mulchi et al, 1982). Noincreased deposition resulting fromcooling-tower operation was detected atthese distances. Deposition rates at thesites ranged from about 0.5 to 1.2 kg/ha(0.4 to 1 lb/acre) per month for NaCl,which comprises most of the solids in thebrackish cooling water. Monitoring sites,which were established to study effects onagricultural crops, were not located inareas closer to the towers because noactive cropland was in these areas andbecause the plant, located on a peninsulaon the Patuxent River, is bounded bywater except to the north and north­northwest. Most drift probably deposits inthe river.

A study of tobacco plants 3 years afterChalk Point cooling towers beganoperating failed to find any increase in leafsalt content that could be attributed todrift (Mulchi and Armbruster 1983).Chloride levels in tobacco and chloride andsodium levels in corn and soybeans at1.6 km (1 mile), the closest distance cropswere grown to the Chalk Point towers,were within the range of preoperationalvalues and were no higher than levelsfound up to 9.6 km (6 miles) from thetowers (Mulchi et al. 1982; Mulchi andArmbruster 1983).

4.3.4.1.3 Effects on Soils

Drift deposition also has the potential todamage vegetation by soil salinization. Soilsalinization does not usually occur in areaswhere rainfall is sufficient to leach saltsfrom the soil profile. In arid regions,however, such as at Palo Verde, coolingtower drift has the potential to increasesoil salinity and thus affect native andagricultural plants (McBrayer and Oakes1982). Salinity of irrigated soils in aridregions may also be increased by drift, eventhough such soils already have a highsalinity resulting from salts in irrigationwater and high evaporation rates.Responses of crop plants to soil salinityappear to be poorly correlated to theirtolerance to foliar-applied salts (GratLanet al. 1981; Maas 1985).

In an experiment in a more humidenvironment, salts were applied to soils tosimulate drift deposition from the ChalkPoint coal-fired plant with brackish watercooling towers. One-time applications of14-112 kglha (13-100 Ib/acre) NaCIaffected leaf Cl- in corn and soybeans butresulted in no visible damage or reductionin yield (Armbruster and Mulchi 1984).These soil salt treatments also increasedsoil pH and extractable cations(Armbruster and Mulchi 1984), butleaching by winter precipitation returnedsoil to pretreatment status.

In humid environments, effects of driftdeposition on soils appear transitory if theycan be detected at all. Field measurementsof the effects of the operating coolingtowers at Chalk Point showed no changesin soil chemical elements at distances of1.6 to 9.6 km (1 to 6 miles) (Mulchi et a1.1982). In a study of five saltwater coolingtowers near Galveston Bay, Texas. saltdeposition up to 746 kg/ha/year was found

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ENVIRONMENTAL IMPACTS OF OPERATION

within 100 m (328 ft) of the towers, withlevels decreasing to <52 kglha (46 Ib/acre)per year at 434 m (1424 ft) (Wiedenfeldet al. 1978). Weekly deposition rangedfrom 4.27 kglha (3.81 Ib/acre) per week to58.8 kglha (52.5 Ib/acre) per week. In thesurvey, salt content of the soil at 104 m(341 ft) from the towers returned toprevious levels when towers were shutdown during the winter.

4.3.4.2 Plant-Specific Operational Data

Annual reports of environmentalmonitoring for vegetation damage atnuclear plants were reviewed. Vegetationmonitoring included detailed measurementsof vegetation structure and composition onpermanent plots, aerial infraredphotography with subsequent field surveysfor vegetation injury, or generalsurveillance. Vegetation damage rangingfrom foliar chlorosis to defoliation can beidentified on false-color infrared aerialphotographs (NUREG/CR-1231).Vegetation monitoring for drift effects hasbeen conducted at 18 nuclear plants. Mostof the nuclear plants are not located closeto agricultural areas, but six of the plantsmonitored crops, pasture, orchards, orornamental vegetation. None reportedvisible damage to ornamental vegetation orreduction in crop yield (Table 4.3).

A detailed study at Palo Verde in Arizonashowed that, aftero years of operation, nochange in agricultural soils attributable tocooling tower emissions occurred.Although significant increases or decreasesoccurred in some soil parameters at somemonitoring locations, these changes appearunrelated to cooling-tower operation andwere believed to have been caused byirrigation management, cropping, andfertilizer application. At the conclusion ofthe 6-year study, no significant effects on

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ENVIRONMENTAL IMPACTS OF OPERATION

Table 4.3 Results of nuclear facility monitoring for cooling-tower drifteffects on terrestrial vegetation

Plant

Arkansas

Beaver Valley

Byron

Callaway

Davis-Besse

Hope Creek

Three Mile Island

Trojan

Catawba

Duane Arnold

Edwin I. Hatch

NUREG-1437. Vol. 1

Vegetation effects

Natural draft

No visible damage; nofoliar chemical changesafter one year

No visible damage

No visible damage

No visible damage

No visible damage

No visible damage afterone year; no foliarchemical changes afterone year

No visible damage

No visible damage

Mechanical draft

Possible ice damage toloblolly pine < 61 m(200 ft) from towers

No visible damage

No visible damage

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Type of monitoring

Aerial photography; foliarchemistry; orchard, nativetrees

Aerial photography; soilpH and conductivity; nativevegetation

Aerial photography; crops;woody, ornamental, andnative vegetation

Aerial photography;permanent vegetation plots;native trees

Aerial photography; soilchemistry; native vegetation

Ground survey; foliarchemistry; soil chemistry;native vegetation

Visual inspection; cropsand native vegetation

Aerial photography;pasture, ornamental andnative vegetation

Aerial photography; groundsurvey; native trees

Visual inspection; nativevegetation

Aerial photography;permanent vegetation plots;native vegetation

ATTACHMENT 5

EMnRONMENTALIMPACTSOFOPERATION

Table 4.3 (continued)

Plant Vegetation effects Type of monitoring

Joseph Farley No visible damage Aerial photography; nativevegetation

Palisades Severe ice damage < 61 Aerial photography;m (200 ft) from towers; permanent vegetation plots;some icing beyond 250 m native vegetation(820 ft); sulfate injury <150 m (492 ft) fromtowers; change invegetation caused bydamage to trees

Palo Verde No visible damage; foliar Aerial photography; foliarsalt concentrations chemistry; soil chemistry;increased on site crops and native vegetation

Prairie Island Frequent ice damage to Aerial photography; groundoaks adjacent to towers; survey; acorn viabilitychange in canopy survey; native vegetationstructure caused by icedamage; reduced viabilityin acorns from oaks neartowers

River Bend No visible damage Aerial photography;permanent vegetation plots;native vegetation

Fort Saint Vrain No visible damage Aerial photography; crops;native vegetation

Washington No foliar chemical Foliar chemistry; soilchanges chemistry; native vegetation

crops or native vegetation had been noted,and the study was discontinued(Halliburton NUS 1992).

At the Palisades plant in Michigan,concern was expressed by owners of nearbyfruit orchards about possible effects ofelevated humidity on the incidence ofdisease, particularly apple scab, in theirorchards. The concern was that increased

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humidity could result in the need forincreased applications of disease-controlsprayings and thus increase orchardoperating costs. NRC staff recommended asurvey program to assess impacts ofcooling-tower moisture on yield, quality,and frequency of disease-control sprayings(NRC 1978). Weather conditionsencouraging apple scab are temperaturesof 17 to 24°C (63 to 75°F) and

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ATTACHMENT 5

ENVIRONMENTAL IMPACTS OF OPERATION---------------------------------;,->85 percent relative humidity for 9 h ormore. A study was conducted to determinethese weather conditions near Palisadescooling towers and in more distant areas(Ryznar et a1. 1980). Long-term weatherrecords from weather stations outside theinfluence of the Palisades cooling towerswere analyzed. In addition, a network ofmeteorological stations was established inthe vicinity of the Palisades plant. Noincrease in weather occurrences favoringapple scab was observed that could berelated to Palisades operation.

4.3.4.3 Conclusion

Monitoring results from the sample ofnuclear plants and from the coal-firedChalk Point plant, in conjunction with theliterature review and information providedby the natural resource agencies andagricultural agencies in all states withnuclear power plants, have revealed noinstances where cooling tower operationhas resulted in measurable productivitylosses in agricultural crops or measurabledamage to ornamental vegetation. Becauseongoing operational conditions of coolingtowers would remain unchanged, it isexpected that there would continue to beno measurable impacts on crops orornamental vegetation as a result of licenserenewal. The impact of cooling towers onagricultural crops and ornamentalvegetation will therefore be of smallsignificance. Because there is nomeasurable impact, there is no need toconsider mitigation. Cumulative impacts oncrops and ornamental vegetation are not aconsideration because deposition fromcooling tower drift is a localizedphenomenon and because of the distancebetween nuclear power plant sites andother facilities that may have large coolingtowers. This is a Category 1 issue.

NUREG-1437, Vol. 1 4-42

4.3.5 Terrestrial Ecology

This section addresses the impact ofcooling tower drift on natural plantcommunities (Section 4.3.5.1) and theimpact of bird mortality resulting fromcollisions with natural-draft cooling towers(Section 4.3.5.2).

4.3.5.1 Effects of Cooling-Tower Drift

This section addresses the extent to whichnatural plant communities near nuclearplants are affected by exposure to salts,icing, or other effects (e.g., fogging andincreased humidity) caused by operation ofcooling towers. The approach to evaluatingthis issue is the same as that used forevaluating the impact on agricultural cropsin Section 43.4.

4.3.5.L1 Overview of Impacts

The potential impacts of cooling toweroperation on native vegetation are similarto those for agricultural crops, includingsalt-induced leaf damage, growth and seedyield reduction, and ice-induced damage(see Section 4.3.4). In addition, nativevegetation may suffer changes incommunity structure (Talbot 1979) inresponse to icc damage or differences inspecies tolerances to drift. Increasedfogging and relative humidity near coolingtowers have little potential to affect nativevegetation, and no such impacts have beenreported.

The following standard of significance isapplied to the effects of cooling toweroperation on natural plant communities.The impact is of small significance if nomeasurable degradation (not includingshort-term, minor, and localized impacts)of natural plant communities results fromcooling tower operation.

ATTACHMENT 5