ML20214E679
| ML20214E679 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 03/31/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| NUREG-1171, NUREG-1171-DRFT, NUDOCS 8603260369 | |
| Download: ML20214E679 (248) | |
Text
{{#Wiki_filter:. p Ke NUREG-1171 Draft Environmental Statement related to the operation of
- South Texas Project, Units 1 and 2 Docket Nos. 50-498 and 50-499 Houston Lighting & Power Company, et al.
U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation March 1986 p "%, e' s j
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NOTICE Availability of Reference Materials Cited in NRC Publications Most documents cited in N RC publications will be available from one of the following sources:
- 1. The NRC Public Document Room,1717 H Street, N.W.
Washington, DC 20555
- 2. The Superintendent of Documents, U.S. Government Printing Office, Post Office Box 37082, Washington, DC 20013-7082 l 3. The National Technical Information Service, Springfield, VA 22161 Although the listing that follows represents the majority of documents cited in NRC publications, it is not intended to be exhaustive.
Referenced documents available for inspection and copying for a fee from the NRC Public Docu. ment Room include NRC correspondence and internal NRC memoranda; NRC Office of Inspection and Enforcement bulletins, circulars, information notices, inspection and investigation notices: Licensee Event Reports; vendor reports and correspondence; Commission papers; and applicant and - licensee documents and correspondence. The following documents in the.NUREG series are available for purchase from the GPO Sales Program: formal NRC staff and contractor reports, NRC-sponsored conference proceedings, and NRC booklets and brochures. Also available are Regulatory Guides, NRC regulations in the Code of Federal Regulations, and Nuclear Regulatory Commission issuances. Documents available from the National Technical Information Service include NUREG series reports and technical reports prepared by other federal agencies and reports prepared by the Atomic Energy Commission, foh. .iner agency to the Nuclear Regulatory Commission. Documents available from public and special technical libraries include all open literature items, such as books, journal and periodical articles, and transactions. Federal Register notices, federal and state legislation, and congressional reports can usually be obtained from these libraries. l Documents such as theses, dissertations, foreign reports and translations, and non NRC conference l proceedings are available for purchase from the organization sponsoring the publication cited. Single copies of NRC draft reports are available free, to the extent of supply, upon written request to the Division of Technical Information and Document Control, U.S. Nuclear Regulatory Com-l mission, Washington, DC 20555.
- Copies of industry codes and standards used in a substantive manner in the NRC regulatory process l are maintained at the NRC Library, 7920 Norfolk Avenue, Bethesda, Maryland, and are available there for reference use by the public. Codes and standards are usually copyrighted and may be purchased from the originating orga'ilzation or, if they are American National Standards, from the
[ American National Standards Institute,1430 Broadway, New York, NY 10018. i
NUREG-1171 Draft Environmental Statement related to the operation of South Texas Project, Units 1 and 2 Docket Nos. 50498 and 50-499 Houston Lighting & Power Company, et al. U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation March 1986 p*"n, a
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ABSTRACT j This Draft Environmental Statement contains the second assessment of the envi-i ronmental impact associated with the operation of the South Texas Project, Units 1 and 2, pursuant to the National Environmental Policy Act of 1969 (NEPA). i and Title 10 of the Code of Federal Regulations, Part 51, as amended, of the ! Nuclear Regulatory Commission regulations. This statement examines the environ-i mental impacts, environmental consequences and mitigating' actions, and environ-mental.and economic benefits and costs associated with station operation. Land
. use and terrestrial and aquatic ecological impacts will be small. No opera-1 tional impacts to historic and archeological sites are anticipated. The effects I of routine operations, energy transmission, and periodic maintenance of rights-i of-way and transmission facilities should not jeopardize any populations of .
- endangered or threatened species. No significant impacts are anticipated from i~
normalfoperational releases of radioactivity. The risk of radiation exposure associated with accidental release of radioactivity is very low. Socioeconomic l impacts of the project are anticipated to be minimal. The action called for is { the issuance of an operating license for South Texas Project,' Units 1 and 2. b d 4 y i 1 2 South Texas DES iii
1
SUMMARY
AND CONCLUSIONS This Draft Environmental Statement was prepared by the U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation (hereinafter referred to as the staff). (1) This action is administrative. (2) The proposed action is the issuance of operating licenses to the Houston Lighting & Power Company, acting as Project Manager on behalf of itself, the City Public Service Board of San Antonio, Central Power & Light Company, and the City of Austin, for the startup and operation of the South Texas Project Units 1 and 2 (STP 1&2), located on the west side of the Colorado River in Matagorda County, approximately 19.3 km (12 miles) south of Bay City, Texas (Docket Nos. 50-498 and 50-499). (3) The facility will employ two identical pressurized water reactors, each to j produce up to approximately 3800 megawatts of thermal energy (MWt). A steam turbine generator will use this heat to provide.up to 1250 megawatts of electrical power (MWe) per unit. The exhaust steam will be condensed by the flow of water in a closed-cycle system incorporating an off-stream cooling lake utilizing makeup water from the Colorado River. Blowdown from the cooling lake will be discharged into the Colorade River. (4) ~The information in this Draft Environmental Statement represents the second assessment cf the environmental impact associated with the South Texas Project pursuant to the guidelines of the National Environ-mental Policy Act of 1969 (NEPA) and 10 CFR Part 51 of the Commission's Regulations. After receipt of an application (1974) to construct this plant, the staff reviewed the impact that would occur during the construc-tion and operation of this plant. That evaluation was issued as a Final Environmental Statement--Construction Phase in March 1975. As the result of that environmental review, a safety review, an evaluation by the Advisory Committee on Reactor Safeguards, and a public hearing in Bay City, Texas, during April 22 and 23, 1975, the Nuclear Regulatory Commission (NRC) issued permits in December 1975 for the construction of Units 1 and 2 of the South Texas Project. As of December 1985, the construction of Unit I was 92.3% complete and Unit 2 was 60.1% complete. With a proposed fuel-loading date of June 1987 for Unit 1 and December 1988 for Unit 2, the applicant has petitioned for licenses to operate the nuclear units and in May 1978 sub-mitted the required safety and environmental reports to substantiate this petition. (5) The staff has reviewed the activities associated with the proposed operation of the plant and the potential impacts, both beneficial and adverse. The NRC staf f's conclusions are summarized as follows: (a) The STP cooling lake will receive an average of 1.03 x 108 m3/ year (83,900 acre-ft/ year) (102,000 acre-ft/ year or 1.26 x 108 m3/ year maximum) of unappropriated water from the Colorado River. The South Texas DES v
consumptive use of water from the Colorado River will amount to about 3.6% of the river's average annual historical flow. Direct rainfall will contribute, on the average, 25,000 acre-ft/ year. Cooling lake blowdown will increase the Colorado River total dissolved solids con-centration incrementally oy about 460 ppm. The thermal alterations and increases in total dissolved solids concentrations will not significantly affect the aquatic productivity of the Colorado River (Section 5.3). (b) Assessments of the impact of station operation on aquatic biological resources of the Colorado River-Matagorda Bay estuary system were conducted during the CP stage review in 1975. Although the impacts of water withdrawal and effluent discharges were found to be minimal, studies were required of the applicant to further refine the assess-ments of impact potentials. Those studies have been completed. This environmental statement utilizes the new and updated information to complete the review of the impact potential of station operation. The impacts are judged to be minimal and acceptable based on: the most recent information; no significant station design changes since the CP stage reviews; and the limitation on station effluent discharges allowable under the USEPA-issued NPPES Permit (Appendix E). The con-clusion of the FES-CP and the Atomic Safety and Licensing Board remain valid (Section 5.5.2). (c) There are no threatened or endangered aquatic species in the site vicinity; therefore no impacts will result from station operation (Section 5.6.2). (d) The operation of the cooling reservoir may adversely alter the marsh to the south of the site. In particular, the species composition and productivity of plant communities in the upper marsh may be affected and valuable habitat for waterfowl and the American alligator may be lost (Section 5.5.1.3). (e) The plant site includes 1367 ha (3378 acres) of prime farmland, about
$ $ of which will be permane'ntly committed. An additional 2550 ha (6300 acres) of land on the site may be unique farmland. About 688 ha (1700 acres) on the site will be set aside as a natural lowland
- habitat. Herbicides are no longer being used in this area; grazing may continue (Section 5.5.1.1). (f) The impacts of plant operation on the terrestrial biota at the site and along transmission lines will be slight (Section 5.5.1.2). (g) No detectable impacts are anticipated from releases of radioactive materials as a consequence of normal operation (Section 5.9). (h) The risk associated with accidental radiation exposure is very low (Section 7). (i) Nothing of known local historic or archaeological interest will be disturbed by the operation of Units 1 and 2 (Section 5.7). South Texas DES vi
(6) This statement assesses various impacts associated with the operation of the facility in terms of annual impacts, and balances these impacts against the anticipated annual energy production benefits. Thus, the overall as-sessment and conclusion would not be dependent on specific operating life'. Where appropriate, however, a specific operating life of 40 years was assumed. (7) This Draft Environmental Statement is being made available to the public, to the Environmental Protection Agency, and to other Federal, State, and local agencies, as specified in Section 8. (8) The~ personnel who participated in the preparation of this statement and their areas of responsibility are identified in Section 7. t (9) -On the basis of the analysis and evaluation set forth in this statement, and after weighing the environmental, economic, technical and other benefits against environmental and economic costs at the operating license stage, it is concluded that the action called for.under NEPA and 10 CFR Part 51 is the issuance of operating licenses for Units 1 and 2 of the South Texas Project subject to'the following conditions for the protection of the environment (Section 6.1): (a) Before engaging in additional construction or operational activities that may result in a significant adverse environmental impact that was not evaluated, the applicant shall provide written notification of such activities to the Director of the Office of Nuclear Reactor Regulation and receive written approval from that office before proceeding with such activities. (b) Monitoring of the aquatic environment shall be as specified in the National Pollutant Discharge Elimination System (NPDES) permit. (c) If adverse environmental effects or evidence of irreversible environ-mental damage develop during the operating life of the plant, the applicant shall provide the NRC staff with an analysis of the problem and a proposed course of action to alleviate it. 1 s South Texas DES vii
i TABLE OF CONTENTS
.Page - ABSTRACT ............................................................. iii
SUMMARY
AND CONCLUSIONS .............................................. v FOREWORD ............................................................. xiii 1 INTRODUCTION ..................................................... 1-1 1.1 Adm i n i s trati ve H i s to ry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 1.2 Permits and Licenses ....................................... 1-2 2- PURPOSE AND NEED FOR THE ACTION .................................. 2-1
-3 ALTERNATIVES TO THE PROPOSED ACTION .............................. 3-1 4 PROJECT DESCRIPTION AND AFFECTED ENVIRONMENT ..................... 4-1 4.1 Introduction ............................................... 4-1 4.2 Facility Description ....................................... 4-1 4.2.1 External Appearance and Plant Layout ............... 4-1
- 4.~ 2. 2 Land Use ........................................... 4-1 4.2.3 Water Use and Treatment ............................ 4-2 4.2.4 Cooling System ..................................... 4-2 4.2.5 Radioactive Waste Management Systems ............... 4-3 4.2.6 Nonradioactive Waste Management Systems ............ 4-4 4.2.7 Power Transmission Systems ......................... 4-5 4.3 Project-Related Environmental Descriptions ................. 4-5 4.3.1 Hydrology .......................................... 4-5 4.3.2 Water Quality ...................................... 4-7 4.3.3 Meteorology ........................................ 4-7 4.3.4 Terrestrial and Aquatic Resources .................. 4-8 4.3.5 Endangered and Threatened Species .................. 4-14 4.3.6 Historic and Archeological Sites ................... 4-15 4.3.7 Socioeconomic Characteristics ...................... 4-15 4.4 References ................................................. 4-15 5 ENVIRONMENTAL CONSEQUENCES AND MITIGATING ACTIONS ................ 5-1 5.1 Introduction ................................................ 5-1 5.2 Land Use .................................................... 5-1 5.2.1 Plant Site and Vicinity .............................. 5-1 5.2.2 Transmission Lines ................................... 5-1 South Texas DES ix
- 3 TABLE OF CONTENTS (Continued)'
P_aSe 5.3 Water ........................................................ 5-2 5.3.1 Thermal .............................................. 5-2 5.3.2 Water Quality ........................................ 5-2. 5.3.3 Water Use ............................................ 5-4 5.3.4 Floodplain Aspects ................................... 5-5 5.4 Air Quality .................................................. 5-6
~5.4.1 Fog.................................................. 5-6 5.4.2 Other Emissions ...................................... 5-6 5.5 . Terrestrial and Aquatic Resources ............................ 5-7 5.5.1 Terrestrial Resources .................................. 5-7 5.5.2 Aquatic Resources ...................................... 5-9 5.6 Endangered and Threatened Species ............................. 5-15 5.6.1 Terrestrial Species ................................... 5-15 5.6.2 Aquatic Species ....................................... 5-15 5.7 Historic and Archeological Sites .............................. 5-15 5.8 Socioeconomic Impacts ......................................... 5-15 5.9 Radiological Impacts .......................................... 5-16 5.9.1 Regulatory Requirements ................................ 5-16 5.9.2 Operational Overview ................................... 5-17 5.9.3 Radiological Impacts from Routine Operations ........... 5-18 5.9.4 Environmental Impacts of Postulated Accidents .......... 5-27 5.9.5 Site-Specific Characteristics .......................... 5-29 5.10 Impacts From the Uranium Fuel Cycle ........................... 5-31 5.11 Decommissioning ............................................... 5-31 5.12 Noise ......................................................... 5-32 5.13 Environmental Monitoring ........................... .......... 5-32 5.13.1 Terrestrial Monitoring ................................ 5-32 5.13.2' Aquatic Monitoring .................................... 5-33 5.13.3 Atmospheric Monitoring ................................ 5-33 5.14 -References .................................................... 5-34 6 EVALUATION OF THE PROPOSED ACTION .................................. 6 6.1 Unavoidable Adverse Impacts ................................... 6-1 6.2 Irreversible and Irretrievable Commitments of Re qurces .... .. . 6-1 6.3 Relationship Between Short-Term Use and Long-Term Productivity ................................................ 6-1 South Texas DES x I
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TABLE OF CONTENTS (Continued) P_a!Le 6.4. Benefit-Cost Summary .......................................... 6-1 6.4.1 Benefits ............................................... 6-2 6.4.2 Economic Costs ......................................... 6-2 6.4.3 Socioeconomic Costs .................................... 6-2 , 6.5 Conclusion .................................................... 6-2 6.6 References .................................................... 6-3 7' CONTRIBUTORS ....................................................... 7-1 8 AGENCIES, ORGANIZATIONS, AND INDIVIDUALS TO WHOM COPIES OF THIS ENVIRONMENTAL STATEMENT ARE BEING SENT ........................... 8-1 9 RESERVED FOR STAFF RESPONSE TO COMMENTS ON THE DRAFT ENVIRONMENTAL STATEMENT ........................................................ 9-1 APPENDIX A RESERVED FOR COMMENTS ON THE DRAFT ENVIRONMENTAL STATEMENT APPENDIX B 'NEPA POPULATION-DOSE ASSESSMENT APPENDIX C IMPACTS OF THE URANIUM FUEL CYCLE APPENDIX 0 EXAMPLES OF SITE-SPECIFIC DOSE ASSESSMENT CALCULATIONS APPENDIX E NPDES PERMIT APPENDIX F ENVIRONMENTAL IMPACTS OF POSTULATED ACCIDENTS APPENDIX G ACCIDENT RELEASE CATEGORY DESCRIPTION APPENDIX H CONSEQUENCE MODELING CONSIDERATIONS APPENDIX I HISTORIC AND ARCHE 0 LOGICAL SITES FIGURES P_ag 4.1 Plant water use ................................................... 4-17 4.2 South Texas Project, Units 1 and 2, transmission routes ........... 4-18 4.3 Co l o ra do R i v e r B a s i n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19 4.4 Hydrologic features ............................................... 4-20 4.5 Map of the lower Colorado River showing sampling stations . . . . . . . . . 4-21 4.6 Little Robbins Slough / Marsh Complex sampling stations ............. 4-22 5.1 100 year floodplains .............................................. 5-37 TABLES P.82 4.1 Plant water use fo.r two units ..................................... 4-23 4.2 Chemicals added to liquid effluents during plant operation ....... 4-24 4.3 New transmission lines, South Texas Project ....................... 4-25 4.4 Summary of characteristics of original and new transmissian line system, South Texas Project .................................. 4-26 l South Texas DES xi 1 i _m . - . . , _ . ._ _ . _ , _ , . . , _ - - - . . _ , _ _ . _ . , , ,._. _ _ _ - .
I i TABLE OF CONTENTS (Continued) TABLES (Continued). Pa2_e 4.5 Cover types, percent areas, and most common dominant plant species in the Little Robbins Slough / Marsh Complex, Fall 1985...... 4-27 4.6 Percent composition of the total catch at each station in the lower Colorado River for the major planktonic and nektonic organisms and annual mean salinities at each station .............. 4-28 4.7 Total number of various organisms sampled during the 1975-1976 survey at lower marsh and Matagorda Bay control stations .......... 4-29 4.8 Commercial finfish landings for the Texas bays and Gulf of Mexico in the vicinity of the South Texas plant, 1979-1983 ............... 4-30 4.9 Commercial shellfish landings for the Texas bays and Gulf of Mexico in the vicinity of the South Texas plant, 1979-1983 ........ 4-30 4.10 Estimated total annual harvest of fishes by weekend sport-boat fishermen for the Matagorda Bay system, for the survey years of 1979-80 through 1983-84 ........................................... 4-31 4.11 Estimated annual harvest of fishes by sport-boat fishermen for marine waters off the Matagorda area of the Texas coast, for the survey years 1982-83 and 1983-84 ................... 4-31 5.1 Cycle makeup water demineralizer waste flow composition ........... 5-38 5.2 Estimate of major STP property tax payments by jurisdiction ....... 5-39
- 5. 3 - (Summary Table S-3) Uranium-fuel-cycle environmental data . . . . . . . . . 5-40
- . 5.4 (Summary Table S-4) Environmental impact of transportation of fuel and waste to and from one light-water-cooled nuclear power reactor ..................................................... 5-42
- 5. 5 Incidence of job-related mortalities .............................. 5-43 5.6 Preoperational radiological environmental monitoring program ...... 5-44 6.1 Benefit-cost summary for South Texas Project, Units 1 and 2 . . . . . . . 6-4 i
f 6 South Texas DES xii v -
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- - FOREWORD
? l This Draft Environmental Statement was prepared by the U.S. Nuclear Regulatory
; Commission (NRC), Office of Nuclear Reactor Regulation (the staff), in accor-
- dance with the Commission's regulations in Title 10 of the Code of Federal l Regulations, Part 51 (10 CFR 51), which implements the requirements of the l National Environmental Policy Act of 1969 (NEPA).
The environmental review presented here deals with the impacts of operation of i the South Texas Project Units 1 and 2 (STP 1&2). . Assessments relating to oper-ation that are presented in this statement augment and update those described in the Final Environmental Statement--Construction Phase (FES-CP) that was issued in March 1975 in support of issuance of the construction permit for-STP 1&2.
- The information in this statement updates the FES-CP in four ways by I (1) evaluating changes in facility design and operation that will result in l environmental effects of operation (including those that would enhance as well as degrade the environment) different from those projected during the preconstruction review l (2) reporting the results of relevant new information that has become F available since the issuance of the FES-CP
- (3) factoring into the statement new environmental policies and statutes that ,
; have a bearing on the licensing action 1
(4) identifying' unresolved environmental issues or surveillance needs that are to be resolved by license conditions Introductory paragraphs in appropriate sections of this statement summarize both . the extent of updating and the staff's assessment of the impacts. t Copies of this statement and the FES-CP are available for inspection at *.he 4 Commission's Public Document Room, 1717 H Street N.W., Washington D.C., and at the Public Document Room, Wharton Jr. College, 911 Boling Highway, Wharton, ! Texas 77488. The documents may be reproduced for a fee at either location. # Copies of this statement may be obtained free of charge by writing to the
- Division of Technical Information and Document Control, Nuclear Regulatory Commission, 1717 H Street, N.W., Washington, D.C. 20555.
. Comments should be filed not later than 45 days after the date on which the Environmental Protection Agency notice of availability of this statement is l
published in the Federal Register. + J. H. Wilson was the NRC Project Manager responsible for preparing the Draft Environmental Statement. i i l South Texas DES xiff i
Comments regarding this document should be addressed to the Project Manager responsible for preparing the Final Environmental Statement: Dr. N. Prasad Kadambi Division of PWR Licensing-A Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 l South Texas DES xiv
1 INTRODUCTION-The proposed action is the issuance of operating licenses to the Houston Lighting
& Power Company, acting as Project Manager on behalf of itself, the City Public Service Board of San Antonio, Central Power & Light Company, and the City of l Austin, for the startup and operation of the South Texas Project, Units 1 and 2 l (STP 1&2), located on the west side of the Colorado River in Matagorda County, approximately 19.3 km (12 miles) south of Bay City, Texas (Docket Nos. 50-498 and 50-499).
I The facility will employ two identical pressurized water reactors, each to
- produce up to approximately 3800 megawatts of thermal energy (MWt). A-steam l turbine generator will use this heat to provide up to 1250 megawatts of elec-trical power (MWe) per unit. The exhaust steam will be condensed by the flow
. .of water in a closed-cycle system incorporating an off-stream cooling lake ! utilizing makeup water from the Colorado River. Blowdown from the cooling lake l will be discharged into the Colorado River. 1.1 Administrative History On July 5,1974, Houston Lighting & Fower Company (HL&P), acting as Project Manager on behalf of itself, the Central Power & Light Company, the city of c San Antonio, and the city of Austin (hereinafter collectively referred to as i the applicant), filed an application with the Atomic Energy Commission (AEC) (now the Nuclear Regulatory Commission) for permits to construct South Texas Project, Units 1 and 2 (STP 1&2). Construction permits CPPR-128 (Unit 1) and l CPPR-129 (Unit 2) were issued on December 22, 1975, following reviews by the l AEC. regulatory staff and the Commission's Advisory Committee on Reactor Safe-guards, as well as a public hearing before an Atomic Safety and Licensing Board in Bay City, Texas, on April 22-23, 1975. The conclusions reached in the staff's environmental review were issued in a Final Environmental Statement--Construction Phase (FES-CP) in March 1975. As of December 1985, construction of Unit I was about 92.3% complete, and the reactor is expected to be ready for fuel loading in June 1987. Unit 2 is about 60.1% complete and has an expected fuel load-ing date of Decemoer 1988. Each unit has a pressurized-water reactor that will produce up to 3800 MWt ant. a net electrical output of 1250 MWe. In July of 1978 the applicant submitted an application including a Final Safety Analysis aaport (FSAR) and an Environmental Report, requesting issuance of operating licenses (ER-OL) for Units 1 and 2. These documents were docketed on July 17, 1978, and the operational safety and environmental reviews were initiated at that time. ! This statement augments and updates the environmental impacts described in the l FES-CP. Introductory paragraphs in Sections 4 and 5 summarize the extent of l updating and the staff's assessment of.any impacts. This draf t statement is being issued for public comments, which should be filed t no later than 45 days after the date on which the Environmental Protection Agency I (EPA) notice of availability is published in the Federal Register. The comments l l South Texas DES 1-1 l l
received will be considered by the staff in the preparetion of its Final Environ-mental Statement. Section 9 of this statement is reserved for the discussion of the staff's responses to the public comments, and Appendix A is reserved for copies of the comment letters. Appendix B contains the population radiation dose assessment according to the 4 National Environmental Policy Act; Appendix C discusses the effects of the uran-fum fuel cycle; and Appendix D gives examples of the site-specific dose assess-ment calculations. The National Pollutant Discharge Elimination System permit issued by the EPA (NPDES) is reproduced in Appendix E. Appendix F reports on the environmental . impacts of postulated accidents. Appendices G and H relate to release categories used in the consequence analysis and consequence modeling considerations, respectively. Correspondence relating to historic and archeo-logic sites in the STP 1&2 area is in Appendix I.
- 1. 2 Permits and Licenses The applicant has provided in Chapter 12 (Amendment 7) of the ER-OL a status listing of environmentally related permits, approvals, and. licenses required from federal and State agencies in connection with the proposed project. NRC staff has reviewed the listing and other information and is not aware of any potential non-NRC licensing difficulties that would significantly delay or pre-clude the proposed operation of South Texas Project, Units 1 and 2. Pursuant to Section 401 of the Clean Water Act of 1972, as amended, the issuance of water quality certification by the State of Texas is a necessary prerequisite to the issuance of an operating license by the NRC. This certification was issued in August of 1985. The National Pollutant Discharge Elimination System (NPDES) permit, issued to the applicant by the U.S. Environmental Protection Agency with an effective date of November 19, 1985, is reproduced in Appendix E of this environmental statement.
I South Texas DES 1-2
2 PURPOSE AND NEED FOR THE ACTION The Commission amended 10 CFR Part 51 effective April 26, 1982,.to provide that need-for power issues will not be considered in ongoing and future operating license (0L) proceedings for nuclear power plants unless a showing of special circumstances is made under 10 CFR 2.758 or the Commission otherwise so requires (47 8 12940, March 26, 1982). Need-for power issues need not be addressed by
' 0L applicants in environmental reports to the NRC, nor by the NRC staff in en-vironmental-impact statements prepared in connection with OL applications-(10 CFR 51.53, 51.95, and 51.106).
The Commission has determined that this policy is justified even in situations where, because of reduced capacity requirements on the applicant's system, the additional capacity to be provided by.the nuclear facility is not needed to meet the applicant's load responsibility. The Commission has taken this action because the issue of need for power is correctly considered at the CP stage of the regulatory review where a finding of insufficient need could factor into denial of issuance of a license. At the OL review stage, the proposed plant is substantially constructed and a finding of insufficient need would not, in itself, result in denial of the OL. ! Substantial information exists that supports the argument that nuclear plants are lower in operating costs than conventional fossil-fueled plants. If conser-vation or other factors lower anticipated demand, utilities remove generating facilities from service according to their costs of operation, with the most expensive facilities removed first. Thus, a completed nuclear plant would serve to substitute for less economical generating capacity (46 B 39440, August 3, 1981, and 47 F_R 12940, March 26, 1982). Accordingly, this statement does not consider need for power. Section 6.4 does, however, consider the savings associated with the operation of the nuclear plant. l 4 South Texas DES 2-1
3 ALTERNATIVES TO THE PROPOSED ACTION The. Commission amended its regulations in 10 CFR Part 51 effective April 26, 1982, to provide that issues related to alternative energy sour ~ces will not be consid-ered in OL proceedings for nuclear power plants unless a showing of special circumstances is made under 10 CFR 2.758 or the Commission otherwise so requires (47 FR 12940, March 26, 1982). In addition, these issues need not be addressed by OEapplicants in environmental reports to the NRC, nor by the NRC staff in environmental impact statements prepared in connection with OL applications (10 CFR.51.53, 51.95, and 51.106(d)). The Commission has concluded that alternative energy source issues are resolved at the construction permit (CP) stage, and the CP is granted only after a find-ing that, on balance, no superior alternative to the proposed nuclear. facility exists. By earlier amendment (46 FR 28630, May 28, 1981), the Commission also stated that alternative sites will not be considered at the operating license stage, except under special circumstances, in accordance with 10 CFR 2.758. Accordingly, this. statement does not consider alternative energy sources or alternative sites. ( South Texas DES 3-1
4 PROJECT DESCRIPTION AND AFFECTED ENVIRONMENT 4.1 Introduction [ This section highlights changes in the plant operating characteristics and design as well as new information on the local environment obtained since the FES-CP was issued in 1975. 4.2 Facility Description 4.2.1 External Appearance and Plant Layout A general description of the External appearance and plant layout is in FES-CP, Section 3. An artist's sketch and site plot plan for the proposed South Texas Project Units 1 and 2 are in f-ES-CP Figures 3.1 and 2.2, respectively. Since publication of the FES-CP, the significant changes that have occurred include the lease of land to Central Power & Light Co. for construction of a
, high-voltage direct current terminal and a building housing an emergency opera-tions center (E0C) and a training facility (see ER-OL. Figure 2.1-5). Fig-ure 3.1-6 in the ER-OL presents a detailed layout of the station.
4.2.2 Land Use A description of regional land use is given in the FES-CP Section 2.2 and.the , ER-OL Section 2.2.2. The site consists of about 5000 ha (12,350 acres), of l which about 2830 hectares (ha) (7000 acres) will be occupied by the cooling pond, as indicated in the FES-CP Section 2.1. No significant changes have occurred in the project site or boundaries since the FES-CP was issued, although minor changes in the location or design of onsite structures (e.g., visitors' center, railroad spur, and switchyard) have occurred. The distances from each of the two units to the exclusion area boundary for 16 sectors are given in the ER-OL Table 2.1. Distances range from 1243 m (4692 ft) to 1985 m (6512 ft). The closest approach of county road FM 521 to the exclusion area boundary is 76 m (249 ft). Since the FES-CP was issued, the applicant has identified approximately 1367 ha (3378 acres) classified as prime agricultural land by the U.S. Soil Conserva-tion Service (ER-OL Fig. 2.7-7). Of this, about 625 ha (1544 acres) were located in the pond area and 81 ha (200 acres) in the area occupied by plant facilities (staff estimate). Approximately 661 ha (1634 acres) of prime agri-cultural land remain' undisturbed, located primarily in the northwest and south-east portions of the site (staff estimate). Some of these areas are in wooded, low-lying, relatively inaccessible places or in small disjunct plots too small i for practical use [i.e., generally less than 8 ha (20 acres) each]. The ap-plicant estimates approximately 144 ha (355 acres) of easily accessed, usable, ; j undisturbed prime farmland remain on site, located in the northwest corner i (response to staff question, ER-OL Appendix 0-6). l l I South Texas DES 4-1
4.2.3 Water Use and Treatment Water for cooling use at the South Texas Project is supplied from the 2800-ha (7000-acre) cooling reservoir. Service water is taken from onsite wells and is treated with sulfuric acid before demineralization and use within the plant (see Section 4.2.4). Water requirements per unit have not changed appreciably since the FES-CP was issued. See Table 4.1 and Figure 4.1 for details of water use at South Texas. Because there have been no appreciable changes to with-drawals and discharges since the FES-CP was issued, Section 3.3 of the FES-CP is still valid. Makeup water for the cooling reservoir will be withdrawn from the Colorado River. In order to minimize the potential for entrainment losses of planktonic organisms, the applicant has committed to limit the makeup water withdrawals as follows (see FES-CP Section 5.5.2.1.1): (1) Makeup water withdrawal will not occur at freshwater river flows less than 300 cfs (8.49 m3/sec), as measured at the upstream Bay City gauging station. (2) Withdrawal can occur when river flows exceed 300 cfs (8.49 m3 /sec), but will be limited to a volume eaual to 55% of the net flow in excess of 300 cfs. The instantaneous rate of water diversion will not exceed 34 m3 /sec 3(1200 cfs) and the annual rate of water diversion will not exceed 1.26 x 108 m (102,000 acre-ft) (FES-CP, Section 3.4.3). When flow exceeds this volume, the makeup water withdrawn will be primarily of freshwater (upstream) origin, and thus tidal flows and concentrations of estuarine-marine organisms in the area of the intake will be relatively low. 4.2.4 Cooling System Mir.or design changes in the heat dissipation syste.a since the FES-CP was issued are summarized below. The maximum flood elevation in the essential cooling pond was increased from 8.8 m (28.8 ft) MSL* to 8.9 m (29.3 ft) MSL. The changes on the cooling reservoirs are: (1) the spillway discharge now calls for 118 m3 /sec (4200 cfs) rather than 122 m3 /sec (4300 cfs); (2) the proposed channel to divert flood water in the west branch of the Colorado River through the spillway has been eliminated; (3) the pumping stations consist of four pumps with a capacity of 6.8 ma /sec (240 cfs) and four pumps with 1.7 m3/sec (60 cfs) in comparison with the previously planned four pumps with 5.7 m3/sec (200 cfs) and four pumps with 2.8 3m /sec (100 cfs); (4) the circulating water discharge structure is 225 m (740 ft) west of the circulating water intake structure rather than 230 m (750 ft) (ER-OL, Section 3.4). These changes should not alter any of the environmental conclusions presented in Section 3.4 of the FES-CP. 4.2.4.1 Intake System Except for the minor design changes noted above, makeup water for the cooling lake will be withdrawn as described in FES-CP Section 3.4.3. In summary, water will be pumped from the Colorado River via a shoreline intake structure and
*MSL = mean sea level.
South Texas DES 4-2
passed through trash racks, and through traveling screens with a 3/8-in. (9.5-mm) mesh. The traveling screens will operate intermittently to coincide with the intermittent withdrawal of river water. Fish collected on the screens can be returned to the. river by being washed off and sluiced through a fish by-pass pipe. The point of return is at the downstream end of the intake structure, approximately 0.6 m (2 ft) below normal water elevation (ER-OL Section 3.4.1.5, ER-OL Figure 3.4-2, and Response to Question 291.5 in ER-0L Amendment 8). 4.2.4.2 Discharge System Except for the minor design changes noted above, the discharge of cooling lake water will be as described in the FES-CP Sections 3.4.2 and 3.4.4. In summary, heat from the circulating water will be dissipated to the atmosphere by use of a 2800-ha (7000-acre) cooling lake. When the cooling lake water level exceeds the normal maximum operating level of 15 m (49 ft) MSL, the excess water can be re-leased through a gated spillway to the Colorado River. Blowdown, from the lake to the river, can be discharged through a 1.7-km (1.1-mile)-long pipeline 2.3 m (90 in.) in diameter. The blowdown line will discharge effluent via seven valved ports along the west bank of the river. Any one or all of the ports can be used, depending on river flow conditions (ER-OL Section 3.4). The NPDES per-mit regulates the discharge temperature, rate, volume, and the number of ports to be used (See permit, Part I.A and Part III, items No. 9 and No. 10, attached as Appendix E of this environmental statement). 4.2.5 Radioactive Waste Management Systems Under requirements set by 10 CFR 50.34a, an application for a permit to construct a nuclear power reactor must include a preliminary design for equipment to keep levels of radioactive materials in effluents to unrestricted areas as low as is reasonably achievable (ALARA). The term ALARA takes into account the state of technology and the economics of improvements in relation to benefits to the pub-lic health and safety and other societal and socioeconomic considerations and in relation to the utilization of atomic energy in the public interest. Appen-dix I to 10 CFR 50 provides numerical guidance on radiation dose design objec-tives for light-water-cooled nuclear power reactors (LWRs) to meet the require-ments that radioactive materials in effluents released to unrestricted areas be kept ALARA. To comply with the requirements of 10 CFR 50.34a(c) for a license to operate a nuclear power reactor, the applicant provided (in FSAR Chapter 11) final designs of radwaste systems and effluent control measures for keeping levels of radio-active materials in effluents ALARA within the requirements of Appendix I to 10 CFR 50. In addition, the applicant provided revised estimates of the quantity of each principal radionuclide expected to be released annually to unrestricted areas in liquid and gaseous effluer.ts produced during normal reactor operations, including anticipated operational occurrences. The NRC staff's detailed evaluation of the radwaste systems and the capability of these systems to meet the requirements of Appendix I will be presented in Chapter 11 of the staff's Safety Evaluation Report (SER). The quantities of radioactive material that the NRC staff calculates will be released from the plant during normal operations, including anticipated operational occurrences, i are in Appendix 0 of this statement, along with examples of the calculated South Texas DES 4-3
doses to individual members of the public and to the general population resulting from these effluent quantities. The staff's evaluation of the solid radwaste system and its capability to accommodate the solid wastes expected during normal operations, including anticipated operational occurrences, also will be presented in Chapter 11 of the SER. The operating licenses for this facility will include Technical Specifications that limit release rates for radioactive material in liquid and gaseous efflu-ents and that require routine monitoring and measurement of all principal release points to ensure that the facility operates in conformance with the radiation-dose-design objectives of Appendix I to 10 CFR 50. NPDES permit number TX 0064947 (see Appendix E) limits the nonradiological components of the radwaste discharge. 4.2.6 Nonradioactive Waste Management Systems 4.2.6.1 Chemical-Waste Treatment The operation of the South Texas nuclear power station will result in discharge of various chemical wastes into the Colorado River via the cooling reservoir. These increased chemical constituents in the leakage and discharge from the cooling reservoir to the Colorado River may result from the (1) concentration of dissolved solids in the cooling reservoir as the result of evaporation and (2) addition of chemicals to various reactor systems. Because there is no significant change in the design of the cooling reservoir and essential cooling pond, the effect of concentration due to evaporation remains the same as in the FES-CP (Table 3.8, FES-CP). The conclusion of Sec-tion 3.6.1 of the FES-CP remains valid. Some design modifications have been made to the nonradioactive chemical-waste system. For example, a reverse osmo-sis unit has been added to the makeup demineralizer water system. The staff has estimated the amount of chemicals added to the liquid effluent (Table 4.2). This represents about a 15% inc.rease in the discharge of sulfate, sodium, and chlorine under maximum operation conditions. 4.2.6.2 Sanitary-Waste Treatment The applicant has indicated plans for a sanitary-waste system adequate for 500 persons. It is noted that about 1,334 employees will be required for operation (see Section 5.8, Socioeconomic Impacts). The sanitary system has a capacity of 0.9 m 3/sec (15,000 gpm). The raw sewage is estimated to have the composition shown in Table 3.7-1 of the ER-OL. Discharge from the sanitary waste treatment system will be to the cooling reservoir (NPDES permit, Appendix E). The sanitary-waste treatment system discharge constituents will be limited by the NPDES permit requirements (Appendix E) for protection of water quality in the Colorado River. It is expected that a larger system will be necessary to comply with effluent limitations. 4.2.6.3 Othcr Waste Treatment A standby diesel system of three diesel engines per unit is provided for emer-gencies. Each diesel engine is estimated to discharge 70 kg/hr (155 lb/hr) and 10 kg/hr (22.5 lb/hr) of sulfur dioxide and nitric oxides, respectively. , l South Texas DES 4-4 i l
r 4.2.7 Power Transmission Systems Since publication of the FES-CP, two changes have been made in the 345 kV transmission line routes. The Danevang Tie Point to Glidden Substation on single circuit steel towers has'been extended past Glidden to a new substation i near Holman. The route to Lon Hill has been changed to go from the site to the
-existing Blessing Substation. This circuit will be on double circuit steel towers from the site-to Prairie Center and on single circuit steel towers from Prairie Center to Blessing Substation. The current and formerly proposed trans-mission lines are shown in Figure 4.2. Distances, corridor widths and approxi- ,
mate number of towers are shown for the modified segments in Table 4.3. The characteristics of the total system are' compared in Table 4.4 for the original system and for the new system incorporating the modifled segments. Further de-scription of the modified segments is in the ER-OL Section 3.9; the original routes are discussed in the FES-CP and the ER-CP. .The transmission lines cross large areas of agricultural land. Using the known county acreages in various land capability classes, the staff has estimated.that about 490 ha (1211 acres) of the approximately 1932 ha (4773 acres) of land in the transmission line cor-ridors could be prime farmland.
'The new-transmission lines required modifications to the existing Blessing Sub-station entailing an area of about 0.8 ha (2 acres) adjacent to existing facili- !
. ties (ER-OL Section 3.9.9). A new substation near Holman occupies about 3.6 ha (8.8 acres) in an area of flat, grassy terrain (ER-OL Section 3.9.9).
4.3 Project-Related Environmental Descriptions 4.3.1 Hydrology 4.3.1.1 Surface Water l The surface water descriptions presented in Section 2.5.1 of the FES-CP are ; still valid as supplemented by the following discussion. In addition, Sec-tion 5.3.3 of this Draft Environmental Statement contains a discussion of the hydrologic. effects of alterations in the floodplain, in compliance with the guidelines for implementing Executive Order 11988 on floodplain management ! (43 FR 6030, February 10, 1978). The South Texas Project is located about 19.3 km (12 mi) south-southwest of
^ Bay City and about 4.8 km (3 mi) west of the Colorado River. .The elevation of the Colorado River adjacent to the plant is about 0.6 m (2 ft) above mean sea level (MSL). By comparison, plant grade elevation is 8.5 m (28 ft) MSL.
' The Colorado River, which will be the source of cooling water for the plant, heads in southeastern New Mexico from where it meanders in a southeasterly direction for about 1430 km (890 mi) to its mouth in the Gulf of Mexico. The
- area of the Colorado River basin is about 10,5670 km 2 (40,800 mi2). Of this total drainage area, only about 74,600 km 2 (28,800 mi2) contribute to runoff in the -lower Colorado River because the upper portion of the basin is a flat semiarid region where rainfall collected in-numerous depressions is dissipat'ed through percolation and evaporation. The topography of the Colorado River basin varies from about 1370 m (4500 ft) at the headwaters to mean sea level at the mouth. A map of the Colorado River basin is shown on Figure 4.3.
South Texas DES 4-5 _ . _ , . . , - - _,.,.n . - - .,n- ,. , , , . . . , ~ , , , , , , _ , , - , . . , - -
Flows in the Colorado River vary over a large range. The average flow at Bay City, approximately 16 miles upstream of the site is 66.4 m 3/sec (2344 cfs) based on records from 1949 to 1984 (water years). The Colorado River upstream of the South Texas plant is regulated by 22 flood-water retaining structures as shown on Figure 4.3. These structures reduce the magnitude of flooding at the site. In addition, there are many diversions for irrigation and municipal water supply. The principal hydrologic feature in the.STP area, other than.the Colorado River, is Little Robbins Slough. This water course flows south from the vicinity of the main cooling reservoir'(MCR) to a coastal marsh area north of Matagorda Bay. The portion of Little Robbins Slough within the MCR area had to be relocated as shown on Figure 4.4 to facilitate construction of the MCR embankment. The re-located channel rejoins the natural drainage course about 1.6 km (1 mi) east of the southwest corner of the MCR. 4.3.1.2 Groundwater The groundwater descriptions in the FES-CP Section 2.5.2 are still valid with the inclusion of the following discussion. The Beaumont Formation which extends to a depth of about 427 m (1400 ft) in the South Texas Project area, is the aquifer that supplies most of the ground-water in the area. Groundwater in this formation is confined under artesian pressure. The aquifer consists of two zones, a deep zone and 'a shallow zone, separated by a confining stiff clay layer about 46 m (150 ft) thick. Ground-water flows in the two zones are virtually opposite to each other. Water in the deep zone has a gradient of 0.3 to 1.1 m/km (5 to 6 ft/mi) and flows to the . northwest because of significant deep well withdrawals in western Matagorda County. In the shallow zone, water flows to the southeast at a gradient of 0.2 to 0.6 m/km (1 to 3 ft/mi). The deep aquifer zone which lies below depths of 76 to 91 m (250 to 300 ft) in
~
I the area of the site provides water of acceptable quality for irrigation and for domestic and most industrial uses. Piezometric levels in this aquifer, which is confined by a 46-m (150-ft)-thick clay layer, range between 15 and 24 m (50 and 80 ft) below the ground surface at the site. Before the deep well withdrawals began which reversed the gradient, the deep aquifer gradient sloped southward toward Matagorda Bay. Recharge to the aquifer beneath the site was by infiltration of precipitation and stream percolation at higher elevations north of the plant where the aquifer crops out. The recharge area begins 13 to 16 km (8 to 10 mi) north of the plant and extends northward to beyond the Matagorda County boundary. In addition to satisfactory water quality, the deep aquifer zone has a high hydraulic conductivity of about 13.6 cm/sec (3.85 x 104 ft/ day) and is thus capable of providing large amounts of water. Wells in the deep zone commonly yield 3790 to 7570 liters / min (1000 to 2000 gpm) with drawdowns of 12 to 30 m (40 to 100 ft). The base of the shallow aquifer zone is 27 to 46 m (90 to 150 ft) deep in the site area. The zone-is divided into a lower and an upper unit. Pumping tests have shown that these two units are confined beneath a surficial clay layer and
- South Texas DES 4-6
F-have piezometric levels ranging between 0.6 and 4.6 m (2 and 15 ft) beneath the ground surface within the site boundary. The hydraulic conductivity of the lower unit is 0.03 cm/sec (85 ft/ day) and its porosity is about 0.37. The upper unit has a hydraulic conductivity of about 0.005 cm/sec (14 ft/ day) and a poros-ity of 0.35. The recharge area for both the lower and upper units of the shal-low aquifer is probably within a few miles north of the plant. Available data indicate that there is no significant recharge to the shallow aquifer from sources within or south of the plant area. Shallow zone water is generally inferior to that of the deep zone. Poor quality shallow groundwater has been encountered in test borings in the plant site and cooling reservoir areas. Wells in this zone have limited production capability; thus, shallow groundwater is used for watering stock and only occasionally for domestic use. Piezometric levels in the shallow' aquifer will be affected somewhat by the water stored in the main cooling reservoir which is located just south of the plant. The differential head between the water level.in the reservoir and the ground-water level outside the reservoir will produce seepage into the upper shallow aquifer. A portion of this seepage will be intercepted by some 700 relief wells located along the perimeter of the MCR embankment. The intercepted flow will be discharged as surface flow through a system of drainage ditches constructed at the downstream toe of the embankment. The remaining seepage is expected to cause a groundwater mound superimposed on the southeastward gradient of the shallow aquifer. However, since the relief wells have been designed to maintain the maximum piezometric level at 8.2 m (27 ft), it is expected that the ground-water mound will be dissipated a relatively short distance from the embankment. 4.3.2 Water Quality Additional river water temperature data for the period October 11, 1966, through September 30, 1976, have been obtained for the Colorado River by the applicant. These additional data do not alter the conclusions in Section 2.5.3 of FES-CP. Water quality data presented in the ER-OL (Sections 5.4 and 6.1) show a wide range of values which are within normal variations that would be expected because of tidal influence. Concentrations of dissolved chemicals in the discharge to the cooling reservoir will be elevated above ambient but should not produce significant changes in the river as a result of discharge (see Section 5.3.2 of this environmental statement). 4.3.3 Meteorology The discussion of the general climatology of the site and vicinity in FES-CP Section 2.6 remains unchanged. However, the following material updates some of the information on severe weather phenomena. About 65 thunderstorms can be expected on about 50 days each year, being most frequent in August. Tornadoes, often spawned by hurricanes, occur in the area. The staff independently examined tornado occurrences in the region, considering observations within the land area of a 2* latitude-longitude square centered on the site. In the period 1954-1981, 250 tornadoes were reported in this area, resulting in a mean annual frequency of 8.9 tornadoes per year. Considering 2 the geographic area examined 28,332 km (10,939 mi2) and the expected tornado path area 0.583 km 2 (0.206 mi2), the staff computed the probability of a South Texas DES 4-7
)
tornado strike at the plant site to be about 1.7 x 10 4 per year, which con- ) verts to a recurrence interval of about 5900 years. An independent study of ; all violent tornadoes reported in the United States for the period 1880 through l 1982 indicated that no tornado associated with any hurricane has exceeded a i maximum wind speed of 260 mph, which is far below the maximum wind speed of ' 161 m/sec (360 mph) associated with the design-basis tornado for the South Texas plant. Hurricanes or remnants of hurricanes pass.through the region occasionally. During the period 1871-1982, about 49 tropical cyclones (tropical depressions, tropical storms, and hurricanes) passed within 185 km (100 nautical miles) of the site. Since the FES-CP was issued, the applicant has collected onsite meteorological data for 3 additional years. For the 4 year period of record (January 1974 throu0h December 1977), wind data at the 10-m (33-ft) level indicate prevailing winds from the southeast, south-southeast, and-south, which occur together about 41% of the time. Winds from the west-southwest, west, and west-northwest occur least frequently, with a total annual frequency of only 4%. The average wind speed at the 10-m level is about 4.8 m/sec (10.7 mph). Calm conditions (defined as wind speeds less than the starting threshold of the anemometer) occur infre-quently at less than 0.2% of the time. Neutral stability (Pasquill Type "D") conditions predominate at the site, occurring about 31% of the time as defined by the vertical temperatures difference between the 60-m and 10-m levels for the 4 year period described above. Moderately stable (Pasquill Type "F") and extremely stable (Pasquill Type "G") conditions occur about 14% and 10% of the time, respectively, for the same stability indicator. 4.3.4 Terrestrial and Aquatic Resources 4.3.4.1 Terrestrial Ecology
.(1) The Site and Transmission Lines Both natural and agricultural communities at the site have been disrupted as a result of construction. The measures taken to protect the site during con-struction are described by the applicant in the ER-OL Section 4.1. During its visits to the site, the staff evaluated these measures and found that proper procedures have been observed and that erosion, dust, and noise have been held to acceptable levels both for the site and for the transmission lines. Revege-tation of the reservoir embankment and pipeline corridors is excellent. For those portions of the site undisturbed by construction, the text and references in the FES-CP provide additional ecological descriptions.
(2) Little Robbins Slough / Marsh Complex At the CP stage, the staff recommended, and the Atomic Safety and Licensing Board agreed, that the applicant undertake a study of the marsh to ascertain how impacts could be minimized. As a part of this work, the applicant con-ducted a vegetation survey of the marsh (NUS, 1976a). The objectives of this survey were to map the wetlands and provide data on species distribution rela-tive to salinity levels of water and of soils. l The area of marsh surveyed comprised 1887 ha (4663 acres) of wetlands, of which ! about 85% was vegetated and 15% was open water. Vegetative cover types were South Texas DES 4-8
i mapped by combining aerial infrared photography with ground observations at 110 points throughout the marsh. Table 4.5 gives the relative areas of the i major cover types and lists the most common dominant plant species reported from the 145 taxa of vascular plants recorded in the survey. ' Communities,
- dominated by one to several species of the emergents listed in Table 4.5, grew
- - in' zones. Mid-emergents were frequent in shallow brackish water (salinity 4
3-10 ppt), short emergents were common on wet brackish soils on the marsh rim, t and tall emergents grew throughout the system. Submergents, and trees and i shrubs, were found in freshwater areas. Since the FES-CP was issued, the ap-plicant has continued remote sensing of the marsh, but other studies have been curtailed by lack of access (the marsh is privately' owned). The remote r nsing has shown an increase in emergent vegetation from 75.5% in 1975 to 78.3% in 1982. This change was probably brought about by reduced freshwater inflow caused by a combination of low precipitation and the presence of the South Texas Project. The shift may be remedied somewhat when the cooling reservoir is completely filled and seepage water is discharged to the marsh. No shifts' in the types of vegetation, such as would be expected from a persistent shift in salinity, have been discerned (Wilkinson,1984). 4.3.4.2 Aquatic Ecology The FES-CP addressed the aquatic ecology of the lower Colorado River, Gulf
- Intracoastal Waterway, and Matagorda Bay. The baseline study period of June j 1973 through May 1974, on which this ecological description was based,.was
- characterized by unusually heavy rainfall and resultant freshwater conditions at the makeup water pumping location and the surrounding South Texas plant environs. Because of these freshwater conditions, ecological data collected during the baseline period were mainly characterized by freshwater organisms and, therefore, did not represent ecological conditions that could occur during
, average pumping operations. Therefore, the NRC staff required an additional year of ecological monitoring in the lower Colorado River. This monitoring program, with its two phases (phase 1 occurring before makeup water pumping arid phase 2 occurring during actual lake filling), is described in Appendix E of the FES-CP (U.S. NRC, 1975). Appendix E of the FES-CP also required that a detailed 1 year study be con-ducted on the Little Robbins Slough to supplement the 1973-1974 baseline study and to determine the effects on the slough from future South Texas Project operations. The following subsections address the ecological conditions of the lower Colorado River and Little Robbins Slough from the data collected during the 1975-1976 phase 1 ecological survey. 4'.3.4.2.1 Lower Colorado River A detailed description of the chemical, physical, and biological data collected . during the 1975-1976 survey is given in the final report of the Colorado River entrainment program (NUS, 1976b), and a more condensed ecological description
.is given in the ER-OL Section 2.7.2.10. A detailed description of the above-mentioned parameters during filling of the cooling reservoir in 1983-1984 is given in the phase 2 reports on the Colorado River (McAden, Greene, and Baker, 1984; 1985).
j South Texas DES 4-9 1
1-Phase 1 of the entrainment monitoring program was conducted from April 1975 to April 1976 and consisted of 26 sampling dates. Samples were taken weekly from March-May and August-December and every other week during January-February and June-July. Freshwater conditions prevailed at the intake area only during two dates (May 6 and August 5, 1975) with low-flow estuarine conditions prevail-ing the remainder of the year (NUS, 1976b). Phase 2 of the entrainment monitor-ing program was conducted at Station 2 from July 1983 through December 1984
- . during cooling reservoir filling (McAden et al., 1984; 1985).
Ichthyoplankton and macrozooplankton samples were taken with a 0.5-mm mesh, conical plankton net at three mid-channel depths during both phase 1 and phase 2 surveys at each station. Oblique tows were also taken parallel to the shoreline at each' station. The stations on the Colorado River are shown in Figure 4.5
- with Station 2 being the area ad'acent 3 to the South Texas plant intake and the only station sampled during phase 2. Detailed sampling methods ~are described in two reports-(NUS, 1976b; McAden et al., 1984).
Macrozooplankton The area of the lower Colorado River between the Gulf Intracoastal Waterway (Station 5) and Station 1.is utilized as a nursery area by both estuarine-marine and freshwater organisms. The extent of the utilization of the river by the different groups depends on the movement and location of the salt wedge. The abundance and occurrence of species at the various stations during the year was influenced by season and salinity. From May-September of the 1975-1976 stud . both freshwater and estuarine-marine decapod larvae dominated the macro-zoorlankton community, and from October-December, estuarine-marine decapod larvae dominated. From January-April abundance and diversity of decapod larvae was low;.the copepod Acartia tonsa dominated (NUS, 1976b). Station 5 was characterized by the highest macroplankton-densities with densities generally . decreasing upriver (Table 4.6) and increasing in the salt wedge (NUS, 1976b). Cladocerans, Malacostraca, and copepods were the most abundant zooplankton invertebrate forms collected in plankton nets during 1983 (McAden et al., '
- 1984). During 1984, the most abundant macrozooplankton were immature stages of the xanthid mud crab (Rhithropanopeus harrisii), ghost shrimp (Callianassa
, -spp.), and jellyfish (Cnidaria) (McAden et al., 1985). The only macrozooplankton occurring in the study area of potential commercial concern are the early life stages of the blue crab (Callinectes sapidus), the white shrimp (Penaeus setiferus), and the brown shrimp (Penaeus aztecus). The megalops stage of the blue crab occurred at all stations but decreased in fie-quency of occurrence and density upriver from Station 5 (Table 4.6). Brown shrimp postlarvae were always taken at Station 5, but Stations 1 and 2 yielded postlarvae in only 3 and 4 samples, respectively. Postlarval white shrimp were taken at all stations but' rarely occurred at Station 1-3 (Table 4.6). Densi-ties of blue crab megalops and white and brown shrimp postlarvae were usually greatest in the salt wedge, and moderate to high densities of megalops fre-quently occurred along the banks (NUS, 1976b). During the phase 2 study, the postlarval. stage of the brown shrimp, the white shrimp, and megalops and juve-nile stages of the blue crab were collected only sporadically and never in very high densities (McAden et al., 1984). The presence of invertebrates in the samples increased with increased salinity. i
~ South Texas DES 4-10
The postlarval stage of the white shrimp, a river shrimp (Macrobrachium Ohione), and a xanthid mud crab (Rhithropanopeus harrisii), were the predominant species
' collected from the sedimentation basin in 1983-84 (McAden et al., 1984; 1985).
Ichthyoplankton Estuarine-marine species dominated throughout the sampling area (Stations 1-5) during 1975-76, primarily as a ' result of an extended period of saltwater influ-ence. Densities were highest from May-October 1975 and March-April 1976. The mean annual relative abundance for estuarine-marine species increased downstream with increasing salinity (Table 4.6). Species of commercial importance which use the area from Stations 1-5 as an estuarine nursery ground are gulf menhaden (Brevoortia patronus), Atlantic croaker (Micropogon undulatus), sand seatrout (Cynoscion arenarius) and spotted seatrout ( k nebulosus), spot (Leiostomus xanthurus), sheephead (Archosargus probatocephalus), pigfish (Orthopristis chrysopterus), black drum (Pogonias cromis) and red drum (Sciaenops ocellata), and southern flounder (Paralichthys lethostigma). The most abundant ichthyo-plankton in the area during 1975-1976 were menhaden, anchovy, croaker, and naked goby (Gobiosoma bosci). Freshwater drum (Aplodinotus grunniens) and cyprinids were abundant during freshwater conditions in early May and August. During 1983-1984, the most abundant ichthyoplankton were bay anchovy and darter (Gobionellus boleosoma) and naked goby. Summaries of the temporal and spatial variation in mean densities of the dominant ichthyoplankton species are given in two reports (NUS, 1976b; McAden et al., 1984, 1985). On the basis of samples taken at Station 2 during 1983-1984, the bay anchovy larvae were the most abundant ichthyoplankters present, possibly as a result of stress from low salinity making these species more susceptible to capture in a plankton net. The darter and naked gobies were the only other species whose larvae occurred in any numbers in the vicinity of the South Texas plant intake structure (McAden et al., 1984; 1985). Nekton 1. Fish and macroinvertebrates were collected by seines and trawls in the vicinity of each station in 1975-76 (NUS, 1976b)~and at Station 2 in 1983-84 (McAden et al. ,1984; 1985). White shrimp (Penaeus setiferus), menhaden, anchovy, croaker, and mullet were the most abundant species taken in the seine and trawl samples in 1975-1976. Except for menhaden, the abundance of the estuarine-marine spe-cies generally decreased upriver from. Station 5 (1cble 4.6). Many of the com-mercially important estuarine-dependent species such as red drum and southern flounder were sampled only at Station 5. Trawl samples indicated that menhaden, the most abundant species, had relatively higher deasities at Station 1. Sein-ing samples indicated the greatest abundance of menhaden at Station 4 (NUS, 1976b). Bay anchovy, the second most abundant ~ species and an estuarine resident, were more abundant at Station 5. Trawl samples also indicated that brown shrimp were relatively abundant at Station 1; seining samples showed that blue crabs were relatively more abundant at Station 1. During 1983-1984, five shrimp, two-crab, and a crayfish species were collected by seines and trawls in the vicinity of Station 2. River shrimp were most common, followed by white shrimp (McAden et al., 1984). 1 South Texas DES 4-11
l 4.3.4.2.2 Little Robbins Slough A detailed description of the temporal and spatial distribution of species, population sizes, and salinity and nutrient regimes in the Little Robbins Slough / Marsh Complex for the 1975-1976 survey is given in the final report on the Little Robbins Slough aquatic ecological studies (NUS,.1976b). A more con-densed' ecological description is presented in the ER-OL Section 2.7.2.11. The purpose of this ecological survey was (1) to define the baseline ecological conditions occurring in the marsh complex so that potential impacts from opera-tion of the South Texas plant could be identified, (2) to assess the relative value of the marsh system as a nursery for estuarine-dependent organisms, and (3) to define the parameters criticai for maintenance of the marsh. Physical, chemical, and biological parameters were monitored at 11 stations in the marsh and at 2 control stations in Matagorda Bay (Figure 4.6). The moni-toring program was conducted during a year characterized by below-average rain-fall and a 7-month drought (ER-OL, Section 2.7.2.11). The 1975-1976 hydrological and nutrient data indicated the existence of two distinct systems in the marsh with respect to nutrient, salinity, and ecolog-
'ical conditions (NUS, 1976b). The area of demarcation between the two systems occurred in the vicinity of Station 97 (Figure 4.6).
A highly seasonal. input of nutrients into the upper freshwater portions of the marsh has originated historically from return flows from rice irrigation in the spring and early summer. Export of nutrients from the upper marsh to the lower marsh is limited; however, some organic detritus input to the lower marsh occurs. During severe flooding, significant export of organic material to the-lower marsh probably occurs. The lower marsh is characterized by high primary production; inorganic nutrients are supplied during tidal inundation and organic materials are exported to the open estuaries on ebb tides. The major factor'affecting the nature of ecological communities within the marsh is salinity. The number of estuarine-marine benthic taxa increases dramatically at Station 97, the upper limit of tidal influence (see also Section 5.5.2.3). During the 1975-1976 study (NUS, 1976b), freshwater conditions prevailed in the upper marsh at Stations 16 and 90-96 and estuarine conditions occurred down . stream from Crab Lake through Stations 98-99. Studies of Little Robbins Slough i wetlands during 1980 showed higher salinities occurring further upstream in the slough (Wilkinson, 1984). Salinity of the lower marsh areas varies greatly and is dependent on freshwater runoff and tidal oscillation. Dissolved oxygen is I l also highly variable and, along with salinity, limits the spatial distribution l and abundance of organisms in the lower marsh. The lower marsh supports the young of many commercially and ecologically-impor-tant species which are estuarine dependent. These species include brown and white shrimp, blue crab, gulf menhaden, bay anchovy, sand seatrout, spot, croaker, and mullet (NUS, 1976b). The total number of the more important macrozooplankton and ichthyoplankton samples at several areas of the marsh and the Matagorda Bay control stations l are shown in Table 4.7. The only macrozooplankton organisms of importance were the zoea, megalops, ati tvenile stages of the blue crab, and the brown and white shrimp postlarva-. In the marsh, white and brown shrimp occurred in the South Texas DES 4-12
greatest densities at Station 99 (Table 4.7); blue crab juveniles occurred at similar densities at all stations. The lower marsh area below Station 97 (the area of the upper limits of tidal influence), therefore, appears to be a nursery area for young shrimp and blue crabs. Ichthyoplankton of the more important species .in the lower marsh include men-haden, spot, croaker, seatrout, and black drum. Menhaden were more abundant at Station 98, croaker and spot occurred in relatively low numbers at all lower marsh areas, and black drum occurred only at Station 98 (Table 4.7). Gizzard shad, threadfin shad, and carp dominated the freshwater ichthyoplankton (NUS, 1976b). Many of the estuarine-dependent fish and crustaceans in the lower marsh are of commercial or sport fishery importance, such as brown and white shrimp, blue crab, menhaden, sand seatrout, spot, croaker, and mullet. Seining collectiens in the marsh indicated that brown shrimp were highest at Station 99, white shrimp at Station 98, menhaden at Station 97, and spot and croaker at Station 99 (Table 4.7). For white shrimp and menhaden, seine catches were higher in the marsh than in Matagorda Bay. 4.3.4.2.3 Fisheries Fisheries in the vicinity of the South Texas plant are discussed in the ER-OL (Section 2.7.2.8. and Response to Question 291.03). The discussion that fol-lows summarizes recent information and harvest data supplied to the staff by the Texas Parks and Wildlife Department. Commercial fishing occurs throughout the site vicinity in the lower reaches of the Colorado River, the Matagorda Bay system, and the Gulf of Mexico. During recent years, total reported finfish landings have ranged between about 138,000 and 225,000 pounds (102,000 kg) (Table 4.8), at ex-vessel (price to the fisher-men) dollar valu.s annually of about $135,000 to $344,000. The primary fin-fishes harvested within the Bay system were red drum, spotted seatrout, black drum, and flounders. The primary finfishes landed from the Gulf of Mexico statistical grid area 19.0 included snapper, grouper, flounder, cobia, red drum, black drum, and spotted seatrout. Commercial landings of shellfishes from the same downstream areas of the site vicinity have ranged between 3.8 million (1.7 million kg) and 8.5 million pounds (3.9 million kg), worth
$3.5 million to $10.4 million (Table 4.9). Harvests from East Matagorda Bay predominantly were blue crabs and some oysters. Matagorda Bay harvests pre-dominantly were penaeid shrimps; blue crabs and oysters were secondary. The Gulf of Mexico shrimp fisheries harvests are monitored by the U.S. Department of Commerce and not by the State of Texas, thus the data are not broken down by grid area as is done with other harvest information. The total Gulf shrimp landings at Texas Ports during the period 1977-1983 ranged between about 52 million (24 million kg) and 82 million pounds (3.7 million kg) annually, worth between $123 million and $157 million (Hamilton and Saul, 1984).
The recreational fisheries of the downstream site vicinity are monitored by the l State of Texas. The estimated annual harvest for the Matagorda Bay system dur-ing recent years has ranged between 35,600 and 113,900 kg (78,485 and 251,107 lb) (Table 4.10). The harvests were composed primarily of spotted seatrout, . l red drum, black drum, southern flounder, and other species (Osburn and Ferguson, 1985). Estimated annual harvests for the pass (inlet) areas of the bay system, South Texas DES 4-13
the Texas Territorial Sea, and the Gulf of Mexico beyond.the Texas Territorial Sea are included in Table 4.11 (in r/9bers of fish; harvest weight was not reported). 4.3.4.2.4 Asiatic Clams On April 10, 1981, the staff issued Inspection and Enforcement Bulletin 81-03 to holders of operating licenses and construction permits requiring them to submit the following information: (1) the known occurrence of Corbicula sp. in the vicinity of their power plants; (2) an inspection of plant equipment.for fouling by Corbicula; and (3) a description of methods (in use or planned) for preventing and detecting fouling by Corbicula. The applicant responded on July 9,.1981, and stated that a number of specimens of Corbicula were found in the main cooling water reservoir on April 30, 1981 (Goldberg, 1981). No studies have been conducted to determine the distribution or abundance of Corbicula in either the reservoir or the Colorado River. A program for moni-toring before operation of Unit I was submitted to the staff. That program will study the abundance, distribution, and sizes of captured clams in the 7000-acre cooling reservoir and in the essential cooling pond (Goldberg, 1983). 4.3.5 Endangered and Threatened Species 4.3.5.1 Terrestrial Species The FES-CP identified the endangered American alligator (Alligator mississippi-ensis) as the only federally endangered or threatened species present on the site (FES-CP, Section 4.3.1.1). Since the FES-CP was issued, the species has been reclassified in Texas and ' Louisiana as " threatened (similarity of appear-ance)" (48 FR 46332, October 12, 1983). This action constitutes formal recog-nition by tIIe U.S. Fish and Wildlife Service (FWS) of the biological recovery of the alligator in Texas. Controlled harvesting of this species is now per-mitted under jurisdiction of the Texas Parks and Wildlife Department (f. Schlicht, Houston Lighting & Power Co., personal communication to J. W. Webb, Oak Ridge National Laboratory, May 2,1985). . The FES-CP identified the federally endangered Attwater's prairie chicken (Tympanuchus cupido attwateri) as present along transmission line rights of way. However, since the FES-CP was issued, the range of this species has contracted, and its continued presence along the rights of way is unlikely (U.S. FWS 1983). The closest known extant population is in Victoria County, several kilometers southeast of the South Texas Project Hill Country transmission line. 4.3.5.2 Aquatic Species On May 2, 1985, NRC staff initiated a formal request for information on the occurrence of threatened or endangered species in the vicinity of the South Texas plant from the U.S. Fish and Wildlife Service under Section 7(c) of the Endangered Species Act Amendments of 1978 (PL 95-632) (Knighton, 1985). The 1 FWS responded on May 30, 1985, and indicated that no threatened or endangered aquatic species occurred near the site (Hall, 1985). i i South Texas DES 4-14
r 4.3.6 Historic and Archeological Sites The applicant has consulted with the Texas Historical Commission (THC) to ensure that the South Texas site and transmission lines will have no impact on historic or archeological sites. The THC has concluded that ongoing operations and maintenance activities will have no effect upon any properties, listed or i eligible for the National Register of Historic Places. 4.3.7 Socioeconomic Characteristics l The general socioeconomic characteristics of the region, including demography i and land use, are presented in FES-CP, Section 2. As indicated in the FES-CP, the plant is located in Matagorda County about 19.2 km (12 mi) south of Bay , 2 City on the west side of the Colorado River. ' 4 . The 16-km (9.9-mi) area surrounding the station is all included in' Matagorda
- . County. The general area is characterized as flat land and is sparsely popu-lated. Beef cattle are grown;-agriculture includes rice and other cropsc The major industrial facilities in the area are the_Celanese Chemical Company located about-5 mi NNE of the plant and the DuPont petrochemical plant located about 7 mi east of the plant.
Matagorda, an unincorporated community, is located about 13.6 km (8.5 mi) southeast of the plant. Nearby major residential areas include Bay City (1980 population--17,837), wnich is about 12 mi NNE of the plant and Palacios (1980 population--4667), which is about 12 mi WSW of the site. According to U.S. Bureau of Census data, the Matagorda County population grew from 15,375 persons in 1970 to 22,504 persons in 1980. i According to the applicant, the 1985 residential population within 16 km (10 mi) of the site was estimated to be 2501 persons. Of the total, 2099 persons are
- in the 8-16-km (5-10-mi) area around the site (see Figure 2.2-1, ER-OL). The
- applicant estimates the residential population in the year 2010 within 10 miles of the site will be 3,955 persons (see Figure 2.2-4, ER-9L).
4.4 References Goldberg, J. H. (Houston Lighting & Power Co.), Letter to K. Seyfrit (NRC),
" Response to IE Bulletin 81-03," July 9,1981.
j -- , Letter (with attachments) to E. L.-Jordan (NRC), " Response to IE Bulletin 81-03 Request for Additional Information," February 11, 1983. Hall, H. D. (U.S. Fish and Wildlife Service), Letter to G. Knighton (NRC), "Re-i sponse_ Letter With Information on Threatened and Endangered Species," May 30, 1985. 4 Hamilton,.C.-L., and G. E. Saul. " Texas Commercial Harvest Statistics, 1977- l 1983." Management Data Series Number 64. Texas Parks and Wildlife Department, !
- Austin, Texas, 1984.
Houston Lighting & Power Co., " Environmental Report, Operating License Stage,_ Vol.-1, South Texas Project, Units 1 and 2," 1978. i j South Texas DES 4-15 i e, , - - < ra-e-w* ,.e-.,% -- ,r---,---- -- ------------&-.,,,,e---=-.v' s- - ?'+----e- ' + - - ' + - - - - - - - + ~ ~ - -M-- - - --mm-t----,- ~
i Knighton, G. (NRC), Letter to H. D. Hall (U.S. Fish and Wildlife Service),
" Request for Information Under the Endangered Species Act," May 2, 1985.
McAden,. D. C. , G. N. Greene, and W. B. Baker, Jr. , Report #1, Colorado River Entrainment and Impingement Monitoring Program. Phase two studies--July 1983-June 1984. . Ecology Division, Environmental Protection Department, Hous-ton Lighting & Power Co., Houston Texas, October.1984.
-- , Report #2, Colorado River Entrainment and Impingement Monitoring Program. -Phase two studies--July-December 1984. Ecology Division, Environmental Protec-tion Department, Houston Lighting & Power Co., Houston Texas, April 1985.
NUS Corporation, " Vegetation of the Little Robbins Slough Wetlands, Matagorda County, Texas," March 19, 1976a.
---3 Final Report, "Little Robbins Slough Aquatic Ecological Studies, April 1975-March 1976," NUS Report No. R-32-00-12/76-656, 1976b.
Osburn, H. R., and M. O. Ferguson, " Trends in Finfish Catches by Private Sport-Boat Fishermen in Texas Marine Waters Through May 1984." Management Data Series Number 78. Texas Parks and Wildlife Department, Austin, Texas, 1985. U.S. Fish and Wildlife Service, "Attwater's Prairie Chicken Recovery Plan," Albuquerque, New Mexico, 1983. U.S. Nuclear Regulatory Commission, " Final Environmental Statement Related to the Proposed South Texas Project Units 1 and 2," Docket Nos. 50-498 and 50-499, March 1975. Wilkinson, D. L. , " Remote Sensing Survey of the Vegetation of Little Robbins Slough Wetlands, Matagorda County, 1982." Final Report submitted to Houston Lightir.g & Power Company by LGL Ecological Research Associates, Inc., November 1984. South Texas DES 4-16
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90 SOUTH TEXAS PROJECT SITE ( LITTLE ROBBINS SLOUGH e 16 { ' ROBBINS LAKE 93 ' 91 , , ROBBINS WEST BRANCH OF COLOR ADO RIVER
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J $- , LEGEND # r: m MATAGORDA BAY LAND 1 MILE
- 13 WATER y, **. MARSH Figure 4.6 Little Robbins Slough / Marsh Complex sampling stations Source: ER-OL Figure 6.1. la South Texas DES 4-22
.- , .__ = . Table 4.1 Plant water use for two units
- Line no. on Figure 4.1 System Flow (gpm)**
1; .Well water supply 750 (norm.) 2 RMS seal water 72 (min.) 3 Water treatment ***
-4' Fire protection tankt ***
5- Potable 45 (norm.) 5a Sewage treatment *** Sb Leaks . 6 Demineralization 225 (norm.) 7 Secondary plant use *** 7a Intermittent systems *** 7b Condensate polishing 225 (norm.) 8 Reactor plant use *** 9- Building drains *** 10 Radwaste *** 80%. 25% capacity capacity factor factor 11 Discharge to reservoirtt- 1.81 x 106 4.5 x 105 12 Auxiliary cooling 23,600 23,600
- 13. Main condensers. 1.81 x 108 4.5 x 105 14* Well water supply 0 0 (alternate) 14t Makeup from main- 550 550 reservoir 15 Blowdown to main 360 360 reservoir
- 16 ' Circulating water system 150 35 seal water 17 Main cooling reservoir - -
makeuptti 18 Main cooling reservoir - - blowdownttt-19 Diesel generator heat 30,000 30,000 exchanger HVAC heat exchanger Component cooling water system neat exchanger Misce'11aneous best exchanger 20 Rainfall. essential 104 104 cooling pond 21 Evaporation essential 310 310 cooling pond 22 Evaporation main cooling 39,200 25,000 reservoir # 23 Rainfall main cooling 15,300 15,300 reservoir South Texas DES 4-23
l l Table 4.1 (Continued) Line no. on Figure 4.1_ System- Flow (gpm)** 80% 25% capacity capacity factor factor 24 Seepage essential .135 135 cooling pond
~25 Seepage main cooling 3,530 3,530 reservoir
*All values and loads are based on an expected average year.
**To convert gpm to liters per minute, multiply by 3.8.
***Will be'provided later.
tAs required. ttContribution from lines Sa, 9, and 10 is approximately 5.6 gpm.** titThe operating mode for reservoir blowdown and makeup is dis- ! cusced in ER-OL Section 3.4.2.
# Includes gross natural and forced evaporation.
Source: ER-OL Table 3.3-1, Amendment 3, 10/10/80, and Amendment'7, 12/21/84. Table 4.2 Chemicals added to liquid effluents during pla'at operation Total discharge (lb/ day) [kg/ day] Chemical Normal operation Maximum operation Phosphate, P04 3- (12) [5.5] (22) [10] Sulfate, 50 42- (770) [350] (4500) [2043] Sodium, Na* (280) [127] (1520) [690] Chlorine - (4000) [1816] Source: ER-OL, Section 3.6 1 L i l South Texas DES 4-24
Table 4.3 New transmission lines, South Texas Project (( Corridor
-g Length width . Area. Approximate .g Line Utility [km] (miles) [m] (feet)' [ha] (acres) no. of towers h STP* to Prairie Center CPL ** '[8.2] (5.1) .[30.5] (100) [25] (62) 27 Prairie Center to CPL [9.7] (6.0) [45.7] (150) [44] (109) 32 Blessing Substation Danevang tie point to C0A*** [116.7) (72.5) -[45.7] (150) [533] (1317) 383 Holman Substation
- South Texas Project.
** Central Power and Light Company.
*** City of Austin Electric Utility.
{l Source: ER-OL, Section 3.9. m 9 t
l Table 4.4 Sum ury of characteristics of original and new trAasmission.line system, South Texas Project
' Characteristic Original system New systen d
Length,.km (miles) 642 (399) 409 (304) No. of highway intersections 41 32
. llighway visibility, km (miles) 208 (129) 135 (84)
No. of railroad intersections 18 14 , No. of nearby residential industrial 7 5 areas
- i No. of natural communities in 945 (2335) 526 (1301) corridors,** ha (acres)
*Within 2-mile (3.2-km) corridor or surrounding a substation'. ** Woodlands, marshlands, or prairie. , Source: ER-CP and ER-OL, Section 3.9.
i i e 1 1-4 i . South Texas ~ DES 4-26 l
. _ . ~ , . . - - - - . - - . _ _ - - - - . - - - . .
Table 4.5 Cover types, percent areas, and most common dominant plant species in the Little Robbins Slough / Marsh Ccmplex, Fall 1975 Percent of total area Common dominants (total = 1887 ha Cover type [4663 acres]) Scientific name Common name Trees and shrubs 1. 6 Salix nigra Black willow Celtis laevigata Sugarberry Aster spinosus Mexican devilweed Iva frutescens Bigleaf sumpweed Tall emergents 18.8 Scirpus californicus Softstem bulrush Typha domingensis Tule Zizaniopsis miliacea Marsh millet Phragmites australis Common reed Mid emergents 24.4 Scirpus maritimus Saltmarsh bulrush Spartina alterniflora Smooth cordgrass Aster tenuifolius Saline aster Distichlis fnicata Saltgrass Short emergents 32.3 Spartina spartinae Gulf cordgrass Alternanthera Alligator weed philoxeroides Persicaria spp. Smartweed Monanthochloe Shoregrass littoralis Submergents 7.4 Najas quadalupensis Southern naiad Ceratophyllum demersum Hornwort Potamogeton pusillas Baby pondweed Chara spp. Chara Floaters 0.1 Nelumbo lutea Yellow lotus Lemna spp. Duckweed Source: NUS, 1976a. South Texas DES 4-27
1 l 1
. Table 4.6 Percent composition of the total catch at each station in the lower Colorado River for the major planktonic and nektonic l organisms and annual mean salinities at each station l l <. Station Catch 1 2 4 5 Zooplankton.
Blue crab (megalops) 1. 3 6. 2 7. 7 84.8 Blue crab (juveniles) 43.6 38.5 3.4 14.5 Brown shrimp (postlarvae) 0.5 0.5 1. 5 97.5 White shrimp (postlarvae) 0.3 0.1 0.8 98.8
'Ichthyoplankton Menhaden 14.8 29.8 11.4 44.0 Anchovy .
0.7 3. 8 7. 2 88.3 Freshwater drum 49.8 39.8 8.9 1. 5 Croaker 15.8 21.3 23.1 39.8 Nekton (trawl) Browr. shrimp 23.3 3.0 -11.3 62.4 White shrimp 11.3 4.5 11.8 72.4 Blue crab 5.4 10.8 0.0 83.8 Menhaden 8.0 22.9 52.6 16.5 Anchovy 8.1 5.7 32.2 54.1 Croaker 11.9 14.9 13.4 59.8 Salinity (annual mean) Surface 1.5 1.1 1. 9 6.1 Bottom 23.8 25.1 25.2 27.3 Source: Compiled from NUS (1976b). s South Texas DES 4-28 l
Table 4.'7. Total number of-various organisms rampled during the 1975-1976 survey at lower marsh and Matagorda Bay control stations Stations Organism 96 97 98 99 12 13 Zooplankton Brown shrimp (postlarvae) - 497 759 1,067 1,507 1,591 White shrimp (postlarvae) 3 344 3,480 5,917 5,584 7,085 Blue crab (juveniles) - 104 128 113 90 48 Ichthyoplankton Menhaden - 435 1,555 398 391 122 Anchovy - 110- 116 18 234 26 Croaker - 1 5 15 84 22 Spot - 22 18 3 100 110 Black drum - - 17 - 164 63 Nekton (seine) Brown shrimp - 286 317 863 1,672 368 White shrimp - 657 10,915 1,169 7,587 5,720 Menhaden 471 17,003 2,231 2,023 1,478 574 ~ Spot 120 20 161 783 227 - Croaker 556 139 605 891 419 - Salinity
- 0-5 -
75 23 25 23 9 5-20 -- 17 72 69 63 27
>20 -
8 5 6 14 64
- Percent of observations when surface salinity was in ranges indicated.
Source: Compiled from NUS (1976b). South Texas DES 4-29 l
.)
Table 4.8 Commercial finfish landings, in pounds * (and the ex-vessel . dollar value) for the Texas bays and Gulf of Mexico in the vicinity of the South Texas plant, 1979-1983 a Bay system i Gulf of Mexico Year East Matagorda Matagorda (statistical grid 19) Total 1979 lb 31,222 54,849 139,739 225,810 ($) (21,883) (38,794) (90,748) (151,425) 1980 lb 43,264 60,658 101,280 205,202 ($) (37,913) (50,733) (133,344) (221,990) 1981-1b 11,977 44,782 81,767 138,526 ($) (11,714) (24,947) (98,989) (135,650) 1982 lb 18,133 12,133 221,452 251,718 (15,835) (11,442) (317,073) (344,350) ($)- 1983 lb 7,892 19,874- 164,165 191,931 ($) (9,102) (18,150) (174,943) (202,195)
- To convert pounds to kilograms, multiply values shown by 0.454.
Source: Hamilton and Saul,1984. Table 4.9 Commercial shellfish landings, in pounds * (and the ex-vessel dollar value) for the Texas bays and Gulf of Mexico in the vicinity of the South Texas plant, 1979-1983 8ay system Gulf of Mexico Year East Matagorda Matagorda (statistical grid 19) Total 1979 lb 222,113 6,179,855 0 6,401,968 (86,099) (6,437,366) - (6,523,465) ($) 471,674 .4,321,999 0 4,793,673 1980 lb (5,013,216) ($) (126,924) (4,886,292) - 111,001 3,724,487 0 (3,835,488) 1981 lb (3,482,837) ($) (67,382) (3,415,455) - 630,153 4,830,310 0 5,460,463) 1982 lb (6,277,940) ($) (189,697) (6,088,243) - 655,511 7,815,786 4,739 8,471,297 1983 lb (10,375,131) ($) (184,120) (10,191,011) (1,648)
*To convert pounds to kilograms, multiply values shown by 0.454.
Source: Hamilton and Saul, 1984 South Texas DES 4-30
Table 4.10 Estimated total annual harvest of fishes by weekend sport-boat fishermen for the Matagorda 8ay system, for the survey years of 1979-80 through 1983 Year Number ' Weight (kg)* 1979-80 96,100 53,300 1980-81 124,400 65,800 1981-82 156,200 72,700 1982-83 61,300 35,600 1983-84 178,700 113,900
*To convert kilograms to pounds, multiply values shown by 2.205.
Source: Osburn and Ferguson, 1985 r Table 4.11 Estimated annual harvest of fishes (in numbers) by sport-boat l fishermen for marine waters off the Matagorda crea of the l Texas coast, for the survey years 1982-83 and 1983-84 Year Pass areas
- Territorial Sea ** Gulf of Mexico **-
l 1982-83 19,100 35,900 58,700 1983-84 32,900 15,700 33,100
- Predominant species included spotted seatrout, red drum, and sheepshead.
** Predominant species included sand seatrout, red snapper, spotted seatrout, and king mackerel.
Source: Osburn and Ferguson, 1985. k South Texas DES 4-31 o
l 5 ENVIRONMENTAL CONSEQUENCES AND MITIGATING ACTIONS 5.1 Introduction This section evaluates changes in predicted environmental impacts since the FES-CP was issued in March 1975. Additional impacts to land use at the site include the construction of the closed-cycle cooling system and the cooling lake as described in Section 5.2.1. Section 5.3.2 discusses the effect of the cooling system. Other_ water use impacts are discussed in Section 5.3.3, and air quality is discussed in Section 5.4. Section 5.5 addresses impacts of operation on terrestrial'and aquatic resources, including the impacts from operation of the cooling tower. Section 5.5.2 presents the staff's updated assessment of the impacts of South Texas Project Units 1 and 2 on aquatic resources resulting from the closed-cycle cooling system (Appendix G). Changes in the predicted socioeconomic impacts of station operation since the FES-CP was issued include an increase in the estimated operating work force, as discussed in Section 5.8. Information in Section 5.9 on radiological impacts has been rev'ised to reflect knowledge gained since the FES-CP was issued. The material on plant accidents includes actual experience with nuclear power plant accidents and.their observed health effects and other societal impacts. Impacts from the uranium fuel cycle, decommissioning, and environmental moni-toring are covered in Sections 5.10, 5.11, and 5.13, respectively. 5.2 Land Use 5.2.1 Plant Site and Vicinity Approximately 1660 ha (4102 acres) of the site have not been altered by con-struction (ER-OL Section 4.3.2), and should not be affected by station opera-tion. The applicant has designated about 688 ha (1700 acres) of_bottomland habitat as a wildlife preserve, although leasing for grazing will continue. About 1.2 ha (3 acres) have been used for a visitors' center and associated facilities. The land outside the exclusion area will continue to be leased for agriculture; the unused land within the exclusion area and around the reservoir will be left alone except for periodic moving. About 661 ha (1633 acres) or 48% of the prime soils on the site will be unaffected by construction or operation. 5.2.2 Transmission Lines l The transmission system, incorporating the modifications described in _ Section 4.2.7, traverses 490 km (304 mi), requiring about 1932 ha (4773 acres) for rights of way. About 73% of the right of way is used for crops and pasture; approximately 490 ha (1211 acres) are potentially prime farmland. Landowners South Texas DES 5-1
retain the right to use power line corridors in ways that do not interfere with normal operation and maintenance. The presence of the transmission lines is not expected to deter the use of land for agricultural purposes significantly. The possible effects of electromagnetic fields associated with high voltage transmission lines include direct biological effects, induced electrical shocks, and interference with cardiac pacemakers. A recent review of this subject for 345-kV and 765-kV transmission lines concluded that serious hazards from these effects are unlikely if certain precautions are taken (Miller and Kaufman, 1978). The applicant plans to minimize these potential problems by " careful design and construction" and by " proper grounding of objects where problems are encountered" (ER-CP, p. 3.9-15). The staff concurs with these plans, but specifically re-quires the applicant to follow the recommendations of the Rural Electrification Administration (1976) regarding grounding and clearances. The staff believes that the measures planned by the applicant to minimize acoustical noise and radio interference resulting from operation of transmission lines (ER-CP, Section 3.9.8) are adequate. Some of the 336 ha (830 acres) of rights of way in wooded areas will have to be cleared periodically for maintenance. Timber may be claimed by the landowner or disposed of in an approved manner by burning, burying, or chipping. The tower bases for the entire system will occupy a total of only about 9.3 ha (-23 acres). The staff co1siders that the impacts of clearing are minor. 5.3 Water 5.3.1 Thermal Within a portion of the river at the discharge, temperature will exceed.the limit specified in water quality standards. Because of the seasonal variabil-ity of water temperatures in the Colorado River, there is no single criterion regarding the size of this mixing zone; however, the mixing zone should not ' exceed 25% of the cross-sectional area and/or volume of flow in the river (FES-CP, Section 5.3.2). In all cases calculated, the temperature differences between the discharge and river temperature were less than the maximum value [3.8 C (6.9 F)] predicted. When this maximum value is exceeded there would be no discharge to the river (FES-CP, Section 5.3.2). At the edge of the 25% mixing zone in the river, the water temperature would not exceed the ambient river temperature by more' than 1.8 C (3.3 F) in fall, winter, and spring, or by 0.6 C (1.1 F) in the summer. Most of the time, these differences would be much less than and would at all times be within thermal discharge limitations (FES-CP, Section 5.3.2). The conclusion stated in Sec-tion 5.3 of FES-CP remains valid. 5.3.2 Water Quality 5.3.2.1 Industrial Chemical Wastes Chemical wastes in the plant effluents result from (1) makeup demineralization water system, (2) chemical cleaning wastes at startup, (3) auxiliary boiler blowdown, (4) condensate polishing demineralizer system, (5) oily waste treat-ment, and (6) circulating water system. The major constituents of the wastes will_be dissolved inorganic chemical substances, measurable as dissolved solids. . South Texas DES 5-2 l
i The demineralizer system contributes most of the volume of chemical waste. Table 5.1 compares the projected concentration in the reservoir with the am- I bient concentration in the river. Discharge from the cooling reservoir to the ' Colorado River may only occur when the freshwater flow of the river (after makeup diversion) is greater than 23 m 3/sec (800 cfs) (minus the makeup water pumping rate) at the Bay City gauging station. The river water must also be flowing toward the Gulf at a velocity of 0.12 m/sec (0.4 fps) or greater for discharge to occur. When these conditions are met, the rate of discharge from the cooling reservoir to the river will be between 2.3 and 8.7 m /sec3 (80 and 308 cfs) (FES-CP, Section 3.4.4). On the basis of these data, the overall ef-fects of reservoir blowdown on the Colorado River should not be significant. 5.3.2.2 Sanitary Wastes The expected volume of sanitary waste for a two-unit plant is 'about 1 m3/sec (15,000 gpm).(see Section 4.2.6). The applicant has indicated that the sani-tary waste will be treated at a sewage treatment plant. The sewage effluents discharged to the reservoir from the treatment facility will meet requirements of the Texas Department of Water Resources Development. 5.3.2.3 Water Quality Standards The Environmental Protection Agency (EPA) effluent guidelines and limitations were issued October 8, 1974, and apply to all steam-electric power generating units with point-source effluents. The National Pollutant Discharge Elimina-tion System (NPDES) effluent limitations applicable to discharges from the South Texas Project power station are presented in Appendix E. The require-ments cover. flow, temperature, suspended solids, oil and grease, 80Ds (5-day biochemical oxygen demand), iron, copper, and total residual chlorine of the discharge. Additional effluent limitations may be imposed by the EPA on a case-by-base' basis. In addition, the following items and specifications are standards of the Texas Department of Water Resources Development applicable to discharge into the Colorado River (blowdown from the cooling lake): (1) dissolved oxygen, not less than 5.0 mg/ liter (2) pH range, 6.5-8.5 (3) fecal coliform, log-mean (average of logarithm of valves) not more than 200 per 100 ml (4) temperature, maximum upper limit 95 F (35 C) and 1.5 F (0.8 C) above natu-ral condition during summer' season and 4 F (2.2 C) above natural condition for spring, fall, and winter The temperature standard allows for a mixing zone of up to 25% of the cross-sectional area of the stream. Studies of the water discharge from the cooling reservoir into the Colorado River indicate that this standard will be met (Section 5.3 of FES-CP).
~
South Texas DES 5-3
5.3.2.4 Effect on Water Users Through Change in Water Quality Any changes in water quality of the Colorado River as a result of.the opera-tion of the South Texas Project are expected to be so small that there will be no significant impacts on use of Colorado River water. No significant impacts on sport and commercial fishing and other recreational activities are expected in the Gulf Intercoastal Waterway, Matagorda Bay, an_d the Gulf of ?!cxico as the result of discharge from the South Texas Plant. See Sections 5.5 and 5.6 below. 5.3.3 Water Use 5.3.3.1 Surface Water Use Sections 3.3 and 5.2.1 of the FES-CP discussed plant water use. These sections are still valid and are updated by the following discussion. Consumptive water use by the plant will consist primarily of forced ano natural evaporation from the 2830 ha (7000 acre) main cooling reservoir (MCR). Under normal operating conditions, about 6.85 x 108 liters / min (1.81 x.108 gpm) will be withdrawn from the MCR and pumped through the main condensers to receive the heat load given up by the condensing steam. The heated water will then be re-turned to the MCR where it will be cooled by evaporation. A smaller amount of water, about 89,330 liters / min (23,600 gpm) will also be withdrawn from the MCR for use in cooling mechanical equipment in the turbine generato'r buildings. After passing through the turbine auxiliary heat exchangers, the heated water will be returned to the MCR for cooling. Makeup water'for the MCR will be ob-tained from the Colorado River. The avera theColoradoRiverwillbeabout1.03x10geannualwithdrawalofwater.from ma (83,900 acre-ft). Of this amount, about 7.56 x 107 m (61,250 acre-ft) will be consumptively used: 4.24 x 107 m 3 3 (34,400 acre-ft) natural evaporation, and 3.32 x 107 m 3 (26,850 acre-ft) forced evaporation. The amount of water consumptively used is only 3.6% of the average annual river flow of 2.10 x 109 m3 (1.7 x 108 acre-ft). However, because of changes in upstream water use, the effect of withdrawing water.from South Texas could change over the life of the plant. At the construction permit stage, the applicant adjusted historical Colorado River flows for anticipated future diver-sions of river water upstream-of the South Texas plant. On the basis of this reduced water availability, the plant consumptive water use would represent 13% of the adjusted annual river flow of 5.80 x 108 m 3 (470,000 acre-ft). 5.3.3.2 Groundwater Use Groundwater is used for certain plant cperations including potable and sanitary purposes. The required groundwater will be obtained from the deep aquifer by three wells located as shown on Figure 4.4. These wells have been located far enough'away from the power block area and from each other to minimize the po-t'ential for regional subsidence due to pumping from the deep aquifer. With-drawal from the deep aquifer is expected to average only about 2839 liters / min (750 gpm) during normal plant operation, which should cause a negligible effect on the water table. No withdrawals will be made from the shallow aquifer zone. I South Texas DES 5-4
5.3.4 Floodplain Aspects The objective of Executive Order 11988, " Floodplain Management" (May 1977), is "to avoid to the extent possible the long and short term adverse impacts asso-ciated with the occupancy and modification of floodplains and to a. void direct and indirect support of floodplain development wherever there is a practicable alternative...." The main cooling reservoir (MCR) which is located just south of the plant occupies a large portion of the original Little Robbins Slough channel and drainage area. To facilitate construction of the MCR embankment, the portion of Little Robbins Slough within the MCR.had to be relocated to the west side of the MCR embankment as shown in Figure 5.1. Because the MCR has been located in the Little Robbins Slough floodplain, it is expected that both the quantity and quality of fresh water reaching the marsh area south of the MCR will be affected. Section 5.5.-l.3 discusses the impact on the Little Robbins Slough / Marsh Complex. To determine how the Little Robbins Slough floodplain has been affected by construction of the MCR and relocation of Little Robbins Slough, the applicant
~
computed 100 year-flood water surface profiles for both pre project and post-project conditions. Since a large portion of Little Robbins Slough is now occupied by the MCP, flood discharges were found to be lower because of the reduced drainage area, and the resulting water level near the plant was found to be about 0.3 m (1 ft) lower for post project conditions. The applicant also determined that the relocated channel has sufficient capacity to carry the'100 year-flood discharge so that the 100 year floodplain will not extend outside of the property limits as shown on Figure 5.1. The staff thus con-cludes that locating the MCR in the Little Robbins Slough floodplain will not affect 100 year-flood levels off site. For the Colorado river, the 100 year floodplain for both pre project and post-project conditions generally follows the northeast and east alignments of the MCR embankment as shown in Figure 5.1. Construction of the MCR, therefore, has affected the floodplain-only minimally, so flood elevations will be essentially the same for pre project and post project conditions. -Construction of the MCR was initiated soon after the applicant received a limited work authorization in September 1975. By'the time the executive order was signed in May 1977, most of the earthwork on the MCR had been completed. It is, therefore, the staff's conclusion that consideration of alternative locations for the MCR is neither required nor practicable. The elevation of the 100 year flood in the Colorado River would vary from about-4.9 m (16 ft) in the vicinity of the spillway discharge channel to about 6.1 m (20 ft) in the vicinity of the makeup intake structure. There are some plant facilities located in the 100 year floodplain. However, the main plant struc-tures at elevation 8.5 m (28 ft) are at a higher elevation than the 100 year floodplain. Plant facilities located in the floodplain are the makeup intake structure, barge slip, spillway discharge structure, and the blowdown discharge pipes. The location of these structures is shown on Figure 5.1. The area occupied by these structures in the floodplain is insignificant when compared South Texas DES 5-5
with the total area in the floodplain. Thus, the reduction in channel convey-ance caused by these structures is minor and the elevations of the 100 year floodplain upstream and downstream of the plant will not be affected by con-struction or operation of the South Texas plant. 5.4 Air Quality 5.4.1 Fog Although not explicitly discussed in tne FES-CP, the applicant assessed the frequency and location of fog and vir,ible moisture plume due to the operation of the cooling reservoir during the review of the construction permit applica-tion. Using the Cooling Reservoir Fog Predictor Model, the applicant estimated that the operation of the cooling reservoir would result in only one additional hour per year of ground fog on Route 60 and FM 1095 above the estimated fre-quency of 120 hours / year of naturally occurring 'og (see Section 2.3.2.3 of the STP PSAR), the applicant also indicated that the must frequent occurrence of elevated [ visible] plumes at a community or town [ unspecified] in the vicinity of.the South Texas site would be 4 hours / year. During the review of the operating license application, the applicant assessed operation of the cooling reservoir on other meteorological parameters such as temperature and relative humidity and concluded that only minimal changes in these parameters would likely occur away from the immediate vicinity of the cooling reservoir. The conclusions of the applicant's analysis of the atmospheric impacts result-ing from operation of the cooling reservoir are similar to the results from studies of other cooling lakes and reservoirs. Typically, atmospheric impacts estimated through predictive models are confirmed through a monitoring program which begins shortly before plant operation and continues for a period considered representative for a given location. The fog monitoring program is discussed in Section 5.13.3 of this statement. 5.4.2 Other Emissions Atmospheric impacts of nonradioactive pollutants were not addressed in the FES-CP. Nonradioactive pollutants (e.g., sulfur dioxide and nitrogen oxides) produced by operation of emergency diesel generators and auxiliary boilers should not significantly degrade air quality in the vicinity of the plant be-cause of infrequent. operation and/or low emission rates. The applicant has received permits from the Texas Air Control Board and U.S. Environmental Protection Agency related to operation of the auxiliary boilers at the South Texas facility. These permits specify acceptable emission rates and stipulate that the maximum sulfur content of the fuel oil for these boilers shall not exceed 0.5% sulfur by weight. I South Texas DES 5-6
5.5 Terrestrial and Aquatic Resources 5.5.1 Terrestrial Resources 5.5.1.1 Impacts on the Site The impacts' of plant operation on the terrestrial biota at the site will be slight. The preservation of approximately 688 ha (1700 acres) of lowland habi-tat in its present state, and the cessation of herbicide usage in that area, is a significant positive effect of the presence of the plant. Unused land within the exclusion area will revert to secondary succession, but will probably be mowed periodically. A significant positive benefit of the project would occur if.this area were actively reseeded and managed as a native prairie. The cool-ing lake will be used by waterfowl, particularly diving ducks. The expected availability of fish in the reservoir may increase the acceptability of the area'for feeding by the endangered bald eagle. Eagles nest in Matagorda and Brazoria Counties, although not on the site. The only animal species on the site that appears on the Federal list of endangered species is the American alligator, now classified as threatened (similarity of appearance). The tem-peratures and food supply (e.g., fish, waterfowl, and turtles) in the cooling reservoir should be adequate all year to support a sizable alligator population, although the structure of the embankments will preclude nesting and the estab-lishment of suitable cover. The applicant estimates that a population of about 25 nonbreeding alligators will be found in the reservoir (ER-OL, Amendment 1). Before construction, 32 American alligators were estimated to be on the site. The assessment of other issues in the FES-CP (Section 5.5.1.1) remains valid. 5.5.1.2 Transmission System Impacts that could be associated with operation of the transmission system include corona effects, induced electric and magnetic fields, bird collisions, and effects resulting from maintenance of the corridors. Corona is noticeable primarily on 500-kV and higher voltage lines, especially during wet weather, but also occurs at lower voltages. Corona may result in audible noise, radio and television reception interference, light, and produc-tion of ozone and oxides of nitrogen (N0x ). The concentration of corona produced ozone is usually less than the daily natural variation in ozone concentration (U.S. Dept. of Energy, 1982) and adverse impacts are consequently unlikely. Production of oxides of nitrogen is similarly insignificant. The applicant has used modern tower designs for the plant transmission system, and these minimize audible noise and interferences (U.S. Dept. of Energy, 1982). Equipment such as tractors operated or parked under the lines can develop a static charge that may cause a slight sensation or shock at a person's touch. Ungrounded fences and gates can develop charges that will deliver a painful shock to a grounded individual touching them (U.S. Dept. of Energy, 1982). Hence, ungrounded fences and gates on or adjacent to the right of way are routinely grounded and electric fences are equipped with drain coils at ap-propriate intervals. These measures will reduce potential shock hazards to levels well below 4.5 mA, which is considered the maximum safe level for chil-dren (U.S. Dept. of Energy, 1982).
. South Texas DES 5-7
Electric fields measured 1 m above ground u,, der 500-kV lines averaged 2.4 kV/m (maximum 6.9 kV/m) on the centerline and 1.3 kV/m (maximum 6.0 kV/m) at the edge of a 30-m~right of way (Sendaula et al., 1983). Fields on a 345-kV line, as in the present case, would be no higher. Experience has shown that calcu-lated values are almost always higher than actual field measurements (Sendaula et al., 1983). Research on effects of electric fields on humans and other organisms has pro-duced variable results (U.S. Dept. of Energy, 1982). For the most part, ad-verse effects have been demonstrated only for higher fields (e.g., greater than 15-kV/m) or longer exposure times than would occur for people residing near or working under transmission lines. Also, some of the studies purporting to demonstrate adverse effects used poor experimental design or inadequate sta-tistical treatment of results (U.S. Dept. of Energy, 1982). Results of research studies on electric field effects on growth and development of plants and animals indicate that neither serious injuries nor abnormalities were apparent from exposure to a 50-kV/m field (Bankoske et al., 1976). Minor physical damage to corn, bluegrass, and alfalfa leaf tips occurred from exposures to field strengths of 15 kV/m and above. The same series of studies, investiga-ting electric field effects on small animals, indicated no apparent adverse abnormalities in behavior or external appearance from exposures to electric fields of 50 kV/m. Bird collisions with power lines are most evident where lines pass through areas with large concentrations of birds, such as reservoirs and certain agricultural fields. Studies on mortality of waterfowl suggest that less than 0.07% of total nonhunting waterfowl mortality is caused by power lines (Stout and Cornwell, 1976). Because concentrations of waterfowl may occur on the South Texas cooling pond, some potential exists for bird colli-sions with the power lines associated with the plant. Because-lines enter the switchyard well north of the cooling pond, however, this possibility is small. Therefore, the impact on waterfowl populations in the area is expected to be negligible. Because the transmission line traverses mostly agricultural land, there will be limited need for right-of-way maintenance. No construction of new permanent access roads will be necessary (ER-OL Section 4.2.4). In wooded areas, peri-odic pruning and cutting of trees and brush, and possibly very limited selec-tive herbicide application, will be necessary (ER-OL Section 5.6.1.1). Typ-ically, herbicides are applied to stumps to keep them from sprouting and as a basal spray on standing brush and trees. All herbicides used in the control programs should be transported, handled, and applied in accordance with the restrictions stated on the registered container labels. Impacts of herbicides on rights of way and correct methods of use were reviewed by Oak Ridge National Laboratory (1985). These maintenance activities will produce little change in the post-construction terrestrial habitat on the right of way and, consequently, no significant adverse impacts. 5.5.1.3 . Impacts on the Little Robbins Slough / Marsh Complex The presence of the cooling reservoir is expected to influence the quality and quantity of freshwater reaching the marsh south of the plant site (NUS, 1976). The possible effects include reductions in freshwater inflow causing slight increases in salinity and changes in the concentrations of important nutrients and total dissolved solids. Since the FES-CP was issued, the applicant hs estimated that the average reduction in freshwater inflow would be only at South Texas DES 5-8
6%, primarily because seepage from the cooling reservoir would compensate for loss of part of the Little Robbins Slough watershed (ER-OL Table 2.5-2). The validity of this estimate remains to be ascertained. The effects of any reduc-tion in freshwater supply to the marsh cannot be confidently predicted, but chronic adverse effects on the marsh could result. In particular, the species composition and productivity of vegetation could be altered, particularly in the upper freshwate'r portion of the marsh. A reduction in suitable nesting habitat for the~American alligator and loss of important habitat for waterfowl in the marsh could also occur. These changes and their potential impact on aquatic ecology are discussed in Section 5.5.2.2, and a monitoring program addressing them is discussed in'Section 5.13. 5.5.2 Aquatic Resources The impacts of operation of South Texas Project on aquatic resources of the Colorado River and Matagorda Bay estuary were considered and assessed in the FES-CP (Sections 5.5.2, 10.1.2, 10.2.2.2, and 11.3) and in the Atomic Safety and Licensing Board's Partial Initial Decision of August 8, 1975 (LBP-75-46) on environmental and site suitability issues. No significant or substantive changes in power station design have occurred since the construction permit (CP) stage assessments that would alter the conclusions on impact potentials. The sections that follow present updated analyses bases on new information that have become available since the CP stage, based on requirements for study in the FES-CP and by the Atomic Safety and Licensing Board's Partial Initial Decision. 5.5.2.1 Intake Impacts Entrainment Impacts associated with the entrainment of ichthyoplankton and macroinverte-brate larvae were addressed in Section 5.5.2.1.1 of the FES-CP. These impacts, however, were based on ecological data collected during the period (June 1973 through May 1974) characterized by unusually heavy rainfall and freshwater conditions in the vicinity of the South Texas Project intake. Because ecolog-ical data collected during this baseline study period were not representative of ecological conditions that probably will occur during average pumping oper-ations, the FES-CP required the applicant to conduct an additional year of ecological monitoring.in the lower Colorado River. An ecologica1 description of the lower Colorado is presented in Section 4.3.4.1. The following will address entrainment impacts based on the data collected during the 1975-1976 and 1983-1984 ecological surveys of the lower Colorado River. The entrainment assessment calculated by NUS (1976b) provided the basis for the applicant's assessment presented in the ER-OL. On the basis of 1975-1976 data, assuming no avoidance of the intake, and assuming repopulation of the area near the intake by tidal and freshwater flow, the NUS (1976b) report calculated that 3.37 x 108 Atlantic croaker, 1.35 x 108 gulf menhaden, and 5.44 x 105 bay anchovy larvae would be entrained during an 8-month period. It was also projected that 1.32 x 108 blue crab and 1.1 x 104 shrimp larvae would be entrained. When the entrainment losses for the above species were considered (NUS,1976b) in terms of their potential impacts on the entire Gulf and Texas coast populations, they were judged to be insignificant because of the abundance of these organisms along the Gulf coast and the high reproductive potential of some organisms South Texas DES 5-9
I (e.g., one female blue crab in her lifetime produces at least as many larvae as were projected to be entrained). Entrainment ' impacts appear insignificant when the entire Gulf or Texas coast populations are considered, thus entrainment impacts on the populations of the lower Colorado River will be addressed. Because of its estuarine nature, the lower Colorado is utilized as a nursery area by estuarine-marine organisms, including the important decapod crustaceans and various fish such as menhaden, anchovy,.and croaker. Menhaden larvae occurred mainly from January through April of 1976. The high-est percentage losses should occur when the concentration of organisms in the intake is several times higher than the river concentration and when tidal flows are high. Anchovy eggs and larvae occurred sporadically throughout the 1975-1976 sampling year. Croaker were entrained mainly from November through January during filling of the reservoir. Shrimp larvae were rarely collected in the vicinity of the South Texas intake (Station 2) during the 1975-1976 study, and brown shrimp larvae were collected only once in the intake area. Anchovies, Jack, pipefish, and various species of gobies were ent ained during the 1983-1984 studies (McAden et al., 1984; 1985). Postlarva .;wn shrimp and ghost shrimp were entrained during 1983-1984. Juveniles and megalops of the blue crab were collected sporadically from September 1975 to April 1976; the highest losses occurred in October. During the 1983-1984 study, blue crabs, e brown shrimp, and white shrimp were collected in low numbers in the vicinity of the intake. Entrainment studies conducted as part of the phase 2 study during filling of the cooling reservoir 1983-1984 showed that the zoea larval stage of the xanthid mud crab, Rhithropanopeus harrisii, occurred in the highest densities in the samples taken from the Colorado River adjacent to the intake structure; the second most abundant forms were the zoeal and postlarval stages of the ghost shrimp, Callianassa spp. Postlarval stages of the brown shrimp. Penaeus aztecus, and the white shrimp, P. setiferus, a commercially important species, and the juvenile stages of the blue crab, Callinectes sapidus, were collected only sporatically (McAden et al., 1984; 1985). Entrainment samples in 1983-1984 yielded eight macroinvertebrate species; five shrimp, two crabs, and a crayfish. There were three penaeid shrimp and two crabs that are estuarine and marine. The freshwater species were the grass shrimp, river shrimp, and crayfish. The river shrimp was the most common
< invertebrate followed by the white shrimp caught in trawls and seines in the vicinity of the South Texas intake.
- The primary ichthyoplankters collected in the vicinity of the plant intake in 1983-1984 were bay anchovies and, to a lesser extent, the darter and naked gobies. Twenty-nine species of fish were reported to have been collected by McAden et al. (1984) and twenty in 1984 (McAden et al., 1985) in trawl and seine samples; four were freshwater species and the remaining were estuarine or marine. The bay anchovy was collected in the greatest numbers during 1983-1984 (McAden et al,, 1984; 1985).
Significance of Entrainment. The significance of the entrainment losses estima-ted for the various species depends on the importance of the lower Colorado South Texas DES 5-10
River as a~ nursery area for these species. It should be noted from the entrain-ment oiscussion of 1975-1976 and 1983-1984 that there may be considerable varia- . tion in the numbers.and kinds of species entrained from year to year. Differ-ences in entrainment rates will be influenced by physical factors such as water flow and salinity in the vicinity of the intake as well as~the population re-cruitment success of the species present. Because of their infrequent occur-rence and low densities in the area of the intake, entrainment of shrimp and blue crab larvae is not expected to be a problem. The staff concludes that entrainment losses for the above species will not con-stitute a significant impact to their respective populations because: (1) Actual entrainment losses probably will be near a median value of about 10% of the organisms passing the intake. (2) This percentage only represents the loss of organisms in the area of the intake influenced by tidal flow and, therefore, does not represent the entire population of the lower Colorado River. (3) The lower Colorado River does not appear to be a unique nursery area for estuarine-marine organisms, but represents one of many such estuarine nurseries found along the Texas and Gulf coasts. (4) Anchovy, menhaden, croaker, and blue crab are ubiquitous and abundant along the Texas and Gulf coast. (5) Most makeup water withdrawal will occur during high river flow conditions when tidal flows and, thus, concentrations of estuarine-marine organisms are low in the area of the South Texas intake. (See Section 4.2.3 for makeup _ water withdrawal limitations.) The FES-CP and Atomic Safety and Licensing Board (ASLB) requirements to obtain data to assess the significance of losses of plankton and crustacean larvae through makeup water entrainment have been fulfilled. The ASLB conclusion that entrainment losses will.be minimized remains valid. Impingement Impingement sampling was conducted during 1983 and 1984 during periods of fill-ing of the cooling reservoir. The highest total number of organisms impinged per two screens for 30 minutes of sampling was 64 (July 13 and 14, 1983) and 13 (September 15 and 16, 1983). At an average volume of 2.4 m2 /sec (85 cfs) and 7.5 m3/sec (260 cfs), respectively, and 24 screens based on the 1983-1984 sam-pling there could potentially have been 768 and 156 individuals impinged during a 30-minute period.' In 1983, three species of fish were collected in the im-pingement samples, each represented by one individual (McAden et al. ,1984). The green sunfish, Lepomis cyanellus, was the only freshwater fish and the only fish species caught by impingement but not by seine or trawl (McAden et al., 1984). In 1984, four macroinvertebrate species were collected, one of which was the pink shrimp, Penaeus duorarum, found only in the impingement samples. Other organisms impinged in 1984 included: P. setiferus; Macrobranchium ohione; and Callinectes sapidus. The total Impingement catch for the July through December 1984 sampling period was 15 individuals ranging in size from 5 mm to 64 mm in length (McAden et al., 1985). South Texas DES 5-11
Because of the small. size (and therefore relatively low swim speed), dense l schooling nature,.and high relative abundance of gulf menhaden at the site, the staff predicts that gulf menhaden could constitute about 65% of_ the totM number of all individuals impinged at the South Texas site. Croaker, anchovy, and mullet could represent about 16%, 10%, and 8%, respectively, of the total numbers, and are expected to be the other major species impinged. The remain-ing species are expected to make up less than 1% of all individuals impinged. In the staff's judgment, impingement losses of. gulf menhaden, croaker, anchovy, and mullet will not constitute a significant impact to their respective popula-tions because: (1) The absolute number of all species impinged is expected to be low, since trawl and seine data indicate relatively low abundances in the site vicin-ity compared to other downstream areas. (2) Screens mounted flush with the shoreline and without protruding sidewalls will: reduce entrapment and prevent concentrations of fish immediately ahead of the screens; lessen the impact of eddy currents on the downstream side of the makeup structure; and allow organisms free passage. The trash racks also permit open passage to the river. Incorporated in the intake design is a fish handling and bypass system which will return impinged organisms to the river downstream of the intake structure. Because the lowest average monthly withdrawals will occur during July through September, impingement of young-of-the year individuals will be minimized. The use of upper stratum river water as makeup will reduce the potential for en-trapment of estuarine organisms found in the lower strata salt wedge. (3) The lower Colorado River is not thought to be a unique nursery area for the fish species discussed above, but represents one of many such estua-rine nurseries found along the Texas and Gulf coasts. (4) Gulf menhaden, croaker, anchovy, and mullet are ubiquitous and abundant along the Texas and Gulf coasts. From these studies, the staff concludes that operation of the South Texas in-take will result in only minor impingement effects on biota in the Colorado River in the vicinity of the intake structure. The conclusions of FES-CP
-Section 5.5.2.1.2 remain valid; as does the ASLB conclusion that impingement losses of aquatic species will be minimized. The U.S. Environmental Protection Agency has approved the intake structures under Section 316(b) of the Clean Water Act (see Appendix E).
5.5.2.2 Thermal Discharge Impacts The FES-CP assessed the potential effects to aquatic biota of the Colorado River and concluded that the effects would be limited to the immediate area of the blowdown diffuser ports (FES-CP Section 5.5.2.2). Similarly, the ASLB (LDP-75-46) concluded that the slight temperature increases expected to occur l in the river from station effluents will not significantly affect the aquatic biological resources of the river. No additional studies specifically related to thermal effluents were required of the applicant. l The CP stage conclusions of no signficant impacts to aquatic biological I resources remain valid based on: (1) no significant design changes in the station discharge system (see Sections 4.2.4 and 5.3.1.1); (2) the applicant's South Texas DES 5-12
recent information, and the staff's conclusion that the Colorado River is not a uniqua nursery area for estuarine-marine organisms, but rather is one of many such areas along the Texas and Gulf coasts (see Section 5.5.2.1 above); (3) the regulation of thermal effluents by a valid NPDES permit that limits the efflu-ent temperature, the blowdown rate, and the blowdown volume (see Appendix E). 5.5.2.3 Impacts on Little Robbins Slough The FES-CP and the ASLB (LBP-75-46) expressed concern that, because of the cooling reservoir, a reduction in freshwater inflow into the upper marsh would result in saltwater intrusion and conversion of freshwater marsh to brackish-water marsh. Concern was also expressed in the FES-CP that a reduction of freshwater inflow would result in reduced nutrient input to the upper marsh. Because of these concerns, Appendix E of the FES-CP required that a baseline ecological monitoring program be initiated in the marsh for the following pur-poses: (1) to define the baseline ecological conditions occurring in the marsh complex so that potential impacts of plant operation could be identified; (2) to assess the relative value of the marsh system as a nursery for estuarine-dependent organisms; and (3) to define the parameters critical for maintenance of the marsh. An ecological description of Little Robbins Slough is presented in Section 4.3.4.2 of this environmental statement. The applicant estimated that the annual freshwater runoff from Little Robbins Slough watershed into the marsh will be reduced by 24% as a result of the im-pact of the cooling reservoir. However, as the result of the seepage flow-from the reservoir, the total long-term average annual reduction of freshwater input to the marsh was estimated to be 6%. According to the applicant, seepage flow will be relatively constant throughout the year, which will ameliorate somewhat the water loss to the marsh system as the result of construction of the cooling reservoir (ER-OL, Section 2.5). Freshwater Flow Reduction A 6% annual reduction in freshwater inflow into the upper marsh is not expected to alter the present structural and functional organization of the aquatic com-munities in the upper and lower marsh because: (1) salinity regimes in the lower marsh (below Station 97) (see Figure 4.6) are governed mainly by fresh-water flow of the Colorado River via the Gulf Intracoastal Waterway (GIW) (water enters the lower marsh, Crab Lake, via Culver's cut, sampling station 12, on the GIW); (2) a culvert or physical barrier above Station 97 (approxi-mately mid-marsh) will retard saltwater encroachment above this point; (3) seep-age flow into the upper marsh will be more constant over the year, which will help to impede salinity intrusion upstream; and (4) organisms in the lower marsh , are adapted to wide variations in salinity regimes. For example, at Stations {; 98 and 99 (Crab Lake) salinities during the 1975-1976 survey ranged from 0-20 ppt about 95% of the time; salinities above 20 ppt occurred about 5% of the time. ! At Station 97 near the upper limit of saltwater occurrence, salinities ranged from 0-5 ppt 75% of the time and 5-20 ppt 17% of the time. A study by Wilkinson (1984) showed that there was considerable temporal variation in salinities from 0.6 to 18 ppt as far upstream as Station 56 during samples taken since 1975. However, the limited salinity measurements do not provide strong evidence for changes in salinity in Little Robbins slough as the result of the cooling reser-voir construction. A small average annual reduction in freshwater input from l South Texas DES 5-13
l the upper marsh (6%) probably will result in salinity regimes in the lower marsh that could potentially display wider "ariations than the situation before reser-voir construction. However, because estuarine organisms in the lower marsh are naturally adapted to wide variations in salinity, a small decrease in freshwater inflow probably would not affect the structural and functional organization of aquatic communities in the lower marsh. Nutrient Input Reduction Reductions in the quantity of nutrient inputs to the upper marsh are expected to occur as a function of reductions in freshwater inflow volumes. Before the cooling reservoir was constructed, the temporal availability of nutrients to the upper marsh was related te the rice-cropping activities above the marsh. Because the presence of the cooling reservoir will not only reduce the fresh-water inflows to the marsh but will also prevent the influx of nutrients from the rice-cropping areas, the quantity and quality of nutrients available to biota of the upper marsh following reservoir construction is a concern. The applicant has estimated that the average total dissolved solids (TDS) level in the reservoir will be 1900 mg/ liter and that an increase in nutrient input to the marsh will occur as the result of reservoir seepage return flow (NUS, 1976b). The applicant has estimated that nutrient levels within the reservoir are ex-pected to become concentrated through natural and forced evaporative loss and that seepage may contribute nutrients in excess (by an order of magnitude) of amounts presently received. The concern relative to the impact of the cooling reservoir on the nutrient regimes of the upper marsh is not only the quantity of nutrients received but also the quality. Nutrient quality relates to the quantity and ratios of the essential nutrients such as nitrate and phosphorus received by the upper marsh. Even though the baseline ecological survey indicated the spatial and temporal patterns of essential nutrients as they presently occur in the upper marsh, it is unknown how the presence of the cooling reservoir will affect the availa-bility of these nutrients to the marsh. Not only are the quality and temporal patterns of occurrence in essential nu-trients unknown for the reservoir, but the quality and patterns of availability of nutrients in the seepage water are unknown. The quantity and quality of essential nutrients in the seepage water could be different from that of the reservoir. Dissolved solids in the reservoir could affect both pH and the availability of nutrients. The principal chemical con-stituents in the blowdown that are elevated above ambient levels are sodium, chloride, total dissolved solids, and to a lesser extent sulfate (ER-OL, Sec-tion 5.4.1). On the basis of the levels in the discharge to the reservoir and the amounts (elevated levels) projected for the discharge to the Colorado River, any increased chemical levels occurring in the seepage should have an insignifi-cant effect on the marsh. Impacts on the lower marsh from potential changes in nutrient quality and quan-tity inputs from the upper marsh are not of concern because the lower marsh ap-parently functions almost independently of the upper marsh. The lower marsh re-ceives nutrients from tidal inflows and the surrounding salt marshes as indicated South Texas DES 5-14
by the higher ano less variable nutrient patterns at lower marsh stations (Stations 99, 98, 12, and 13) compared with upper marsh stations (NUS, 1976b). 5.6 Endangered and Threatened Species 5.6.1 Terrestrial Species Vertebrates such as fish, turtles, and waterfowl in the cooling pond will pro-vide food for the American alligator and possibly for the American bald eagle. Although not occurring at present along transmission line corridors, the endangered Attwater's prairie chicken may find suitable habitat along the corridors. No other effects on endangered or threatened terrestrial species are anticipated. 5.6.2 Aquatic Species There are no threatened or endangered aquatic species in the South Texas Project site vicinity (seo Section 4.3.5.2); therefore, no impact will result from operation of the facility. 5.7 Historic and Archeological Sites The applicant has consulted with the Texas Historical Commission (THC) with regard to the STP 1&2 site and transmission lines. The THC concluded that ongoing operations and maintenance activities will'have no effect on any properties listed or eligible for the National Register of Historic Places (see Appendix I). 5.8 Socioeconomic Impacts The socioeconomic impacts of the operation of South Texas Project Units 1 and 2 are discussed in CP-FES Section 5.6. At present it is estimated that about 1,334 employes will be required for the operation of Units 1 and 2. In addi-tion, about 500 contract employees will be required for outage-related work. More than 400 operating workers are already on the site. Workers-still to be hired are likely to reside in locations similar to places where present plant employees live. Thus, about 70% of the workers are expected to live in Mata-gorda County, of whom about 75% will reside in Bay City, about 12% will reside in Palacios, and the rest in the surrounding areas in the Co"nty. About 14% of the total employees are expected to live in Brazoria County; the rest in other surrounding counties. Because of the distribution and, relative to the con-struction work force, the small number of workers needed for plant operation, the impact on traffic and on the communities in which they reside is expected to be minimal. The average annual workers' payroll is projected to be about $63 million (in 1989 dollars). Local annual purchases of materials and supplies relating to the operation of the plant is expected to total $770,000 (in 1991 dollars). Local purchases are expected to be made primarily in Brazoria, Harris, Matagorda, Calhoun, and'Wharton counties. Table 5-2 shows the estimated major property taxes for the first 5 years of operation. South Texas DES 5-15
5.9 Radiological Impacts 5.9.1 Regulatory Requirements Nuclear power reactors in the United States must comply with certain regulatory requirements in order to operate. The permissible levels of radiaticn in unrestricted areas and of radioactivity in effluents to unrestricted areas are recorded in 10 CFR 20, " Standards for Protection Against Radiation." These regulations specify limits on levels of radiation and limits on concentrations of radionuclides in the facility's effluent releases to the air and water (above natural background). The radiation protection standards of 10 CFR 20 specify limitations on whole-body radiation doses to members of the general public in unrestricted areas at three levels: 500 mrem in any calendar year,100 mrem in any 7 consecutive days, and 2 mrem in any 1 hour. These limits are consis-tent with national and international standards in terms of protecting public health and safety. In addition to the radiation protection standards of 10 CFR 20, 10 CFR 50.36a contains license requirements that are to be imposed on licensees in the form of Technical Specifications on effluents from nuclear power reactors to keep releases of radioactive materials to unrestricted areas during normal opera-tions, including expected operational occurrences, as low as reasonably achiev-able (ALARA). Appendix I to 10 CFR 50 provides numerical guidance on dose-design objectives for light-water reactors (LWRs) to meet the ALARA requirement. Applicants for permits to construct and for licenses to operate an LWR shall provide reasonable assurance that the following calculated dose-design objectives will be met for all unrestricted areas: 3 mrem per year to the total body or 10 mrem per year to any organ from all pathways of exposure from liquid efflu-ents; 10 mrad per year gamma radiation or 20 mrad per year beta radiation air dose from gaseous effluents near ground level and/or 5 mrem per year to the total body or 15 mrem per year to the skin from gaseous effluents; and 15 mrem per year to any organ from all pathways of exposure from airborne effluents that include the radioiodines, carbon-14, tritium, and the particulates. Experience with the design, construction, and operation of nuclear power reactors indicates that compliance with these design objectives will keep average annual releases of radioactive material in effluents at small percentages of the limits specified in 10 CFR 20 and, in fact, will result in doses generally below the dose-design objective values of Appendix I to 10 CFR 50. At the same time, the licensee is permitted the flexibility of operation, compatible with considera-tions of health and safety, to ensure that the public is provided a dependable source of power, even under unusual operating conditions that may temporarily result in releases higher than such small percentages but still well within the limits specified in 10 CFR 20. In addition to the impact created by facility radioactive effluents as discussed above, within the NRC policy and procedures for environmental protection de-scribed in 10 CFR 51 there are generic treatments of environmental effects of all aspects of the uranium fuel cycle. These environmental data have been summarized in Table S-3 (reproduced herein as Table 5.3).and are discussed in Section 5.10 below. In the same manner, the environmental impact of transportation of fuel and waste to and from an LWR is summarized in Table S-4 (reproduced herein as Table 5.4) and discussed in Section 5.9.3.1.2 of this report. South Texas DES 5-16
EPA has established, in 40 CFR 190, an additional operational requirement for uranium fuel cycle facilities including nuclear power plants. This regulation limits annual doses (excluding radon and daughters) for members of the public to 25 mrem total body, 75 mrem thyroid, and 25 mrem other organs from all fuel-cycle facility contributions that may impact a specific individual in the public. 5.9.-2 Operational Overview During normal operations of the South Tex;s plant, small quantities of radio-activity (fission, corrosion, and activation products) will be released to the environment. As required by NEPA, the staff has determined the estimated dose-to members of the public outside of the plant boundaries as a result of the radiation from these radioisotope releases and relative to natural-background-radiation dose levels. These facility generated environmental dose levels are estimated to be very small because of.both the plant design and the development of a program that will be implemented at the facility to contain and control all radioactive emissions and effluents. Radioactive-waste management systems are incorporated into the plant and are designed to remove most of the fission product radioac-tivity that is assumed to leak from the fuel, as well as most of the activation and corrosion product radioactivity produced by neutrons in the vicinity of the reactor core. The effectiveness of these systems will be measured by process and effluent radiological monitoring systems that permanently record the amounts of radioactive constituents remaining in the various airborne and waterborne process and effluent streams. The amounts of radioactivity released through vents and discharge points to areas outside the plant boundaries are to be recorded and published semiannually in the radioactive effluent release reports for the facility. Airborne effluents will diffuse in the atmosphere in a fashion determined by the meteorological conditions existing at the time of release and are generally dispersed and diluted by the time they reach unrestricted areas that are open to the public. Similarly, waterborne effluents will be diluted with plant waste water, with the cooling pond water, and then further diluted as they mix with the Colorado River and the bays and gulf beyond the plant boundaries. Radioisotopes in the facility's effluents that enter unrestricted areas will ' produce doses through their radiations to members of the general public in a manner similar to the way doses are produced from background radiations (that is, cosmic, terrestrial, and internal radiations), which also includes radiation from nuclear weapons fallout. These radiation doses can be calculated for the many potential radiological-exposure pathways specific to the environment around the facility, such as direct-radiation doses from the gaseous plume or liquid effluent stream outside of the plant boundaries, or internal-radiation-dose commitments from radioactive contaminants that might have been deposited on vegetation, or in meat and fish products eaten by people, or that might be present in drinking water outside the plant or incorporated into milk from nearby farms. These doses, calculated for the " maximally exposed" individual (that is, the hypothetical individual potentially subject to maximum exposure), form the basis for the staff's evaluation of impacts. Actually, these estimates are for a fictitious person because assumptions are made that tend to overestimate the dose that would accrue to members of the public outside the plant boundaries. South Texas DES 5-17
For example,.if this " maximally exposed" individual were to receive the total-body dose calculated at the plant boundary as a result of external exposure to the gaseous plume, that individual is assumed to be physically exposed to gamma radiation at that boundary for 70% of the year, an unlikely occurrence. Site-specific values for various carameters involved in each dose pathway are used in the calculations. These include calculated or observed values for the amounts of radioisotopes released in the gaseous and liquid effluents, meteor-ological information (for example, wind speed and direction) specific to the site topography and effluent release points, and hydrological information pertaining to dilution of the liquid effluents as they are discharged. An annual-land census will identify changes in the use of unrestricted areas to permit modifications in the programs for evaluating doses to individuals from principal pathways of exposure. This census specification will be incor-porated into the Radiological Technical Specifications and satisfies the requirements of Section IV.8.3 of Appendix I to 10 CFR 50. As use of the land surrounding the site boundary changes, revised calculations will be made to ensure that the dose estimate for gaseous effluents always represents the highest dose that might possibly occur for any individual members of the public for each applicable food-chain pathway. The estimate considers, for example, where people live, where vegetable gardens are located, and where milk cows and beef cattle are pastured. An extensive radiological environmental monitoring program, designed speciff-cally for the environs of the South Texas plant, provides measurements of radia-tion and radioactive contamination levels that exist outside of the facility boundaries both before and after operations begin. In this program, offsite radiation levels are continuously monitored with thermoluminescent detectors (TLDs). .In addition, measurements are made on a number of types of samples from the surrounding area to determine the possible presence of radioactive contaminants that, for example, might be deposited on vegetation, be present in drinking water outside the plant, or be incorporated into cow's milk from nearby farms. The results for all radiological environmental samples measured during a calendar year of operation are recorded and published in the Annual Radiologi-cal Environmental Operating Report for the facility. The specifics of the final operational-monitoring program and the requirement for annual publication of the monitoring results will be incorporated into the operating license radio-logical Technical Specifications for the South Texas facility. 5.9.3 Radiological Impacts From Routine Operations 5.9.3.1 Radiation Exposure Pathways: Dose Commitments The potential environmental pathways through which persons may be exposed to radiation originating in a nuclear power reactor are shown schematically in Figure F.1 (Appendix F). When an individual is exposed through one of these pathways, the dose is determined in part by the amount of time spent in the vicinity of the source, or the amount of time the radioactivity inhaled or ingested is retained in the individual's body. The actual effect of the.radia-tion or radioactivity is determined by calculating the dose commitment. The annual dose commitment is calculated to be the total dose that would be re-ceived over a 50 year period, following the intake of radioactivity for 1 year under the conditions existing 20 years after the station begins operation. South Texas DES 5-18
(Calculation for the' 20th year, or midpoint of station operation, represents an average exposure over the life of the plant.) However, with few exceptions, most of the internal dose commitment for each nuclide is given during the first few years after exposure because of the turnover of the nuclide by physiological processes and radioactive decay. A number of possible exposure pathways to humans are appropriately studied to determine the impact of routine releases from the South Texas facility on members of the general public living and working outside of the site boundaries and whether the releases projected at this point in the licensing process will in fact meet regulatory requirements. A detailed listing of these exposure' pathways would include external radiation exposure from the gaseous effluents, inhalation of iodines and particulate contaminants in the air; drinking milk from a cow or goat or eating meat from an animal that feeds on open pasture near the site on which iodines or particulates may be deposited, eating vegetables from a garden near the site that may be cantaminated by similar deposits, and drinking water or eating fisn caught nea: the point of discharge of liquid effluents. Other less important potential pathways include: external irradiation from radionuclides deposited on the ground surface; eating animals and food crops raised near the site on irrigation water that may contain liquid effluents; shoreline, boating and swimming activities near the waters that may be contamin-ated by effluents; drinking potentially contaminated water; and direct radiation from within the plant itself. The South Texas design does not provide for dis-posal of waste (radiological or nonradiological) through underground injection; thus there is no impact on groundwater and its users from such a potential path-way. The only release of radioactive liquid is through the station discharge to the cooling pond and thence to the river where contaminants are diluted to meet the requirements of 10 CFR 20 and Appendix I to 10 CFR 50, as discussed in Section 4.2.5. There is currently no drinking water pathway of concern. There is also no reported use of Colorado River water for irrigation downstream of the South Texas site. Calculations of the effects for most pathways are limited to a radius of 80 km (50 mi). This limitation is based on several facts. Experience, as demonstrated by calculations, has shown that all individual dose commitments (0.1 mrem or more per year) for radioactive effluents are accounted for within a radius of 80 km from the plant. Beyond 80 km, the doses to individuals are smaller than 0.1 mrem per year, which is far below natural-background doses, and the doses are subject to substantial uncertainty because of limitations of predictive mathematical models. The staff has made a detailed study of all of the above important pathways and has evaluated the radiation-dose commitments both to the plant workers and the general public for these pathways resulting from routine operation of the facility. A discussion of these evaluations follows. (1) Occupational Radiation Exposure for Pressurized-Water Reactors Most of the dose to nuclear plant workers results from external exposure to radiation coming from radioactive materials outside of the body rather than from internal exposure from inhaled or ingested radioactive materials. Expe-rience shows that the dose to nuclear plant workers varies from reactor to reactor and from year to year. For environmental-impact purposes, it can be South Texas DES 5-19
projected by using the experience to date with modern pressurized-water reac-tors (PWRs). Recently licensed 1000-MWe PWRs are operated in accordance with the post-1975 regulatory requirements and guidance that place increased empha-sis on maintaining occupational exposure at nuclear power plants ALARA. These requirements and guidance are outlined primarily in 10 CFR 20, Standard Review Plan Chapter 12 (NUREG-0800), and Regulatory Guide 8.8, "Information Relevant to Ensuring That Occupational Radiation Exposures at Nuclear Power Stations Will Be as Low as Is Reasonably Achievable." The applicant's proposed implementation of these requirements an'd guidelines is reviewed by the staff during the licensing process, and the results of that review are reported in the SER. The license is granted only after the review indicates that an ALARA program can be implemented. In addition, regular reviews of operating plants are performed to determine whether the ALARA requirements are being met. Average collective occupational dose-information for 373 PWR reactor years of operation is available for.those plants operating between 1974 and 1983. (The year 1974.was chosen as a starting date because the dose data fo_r years before 1974 are primarily from reactors with average rated capacities below 500 MWe.) These data indicate that the average reactor annual collective dose at PWRs has been about 510 person-rem, although some plants have experienced annual collec-tive doses averaging as high as about 1350 person-rem per year over their oper-ating lifetime (NUREG-0713, Vol. 5). These dose averages are based on widely varying yearly doses at PWRs. For example, for the period mentioned above, annual collective doses for PWRs have ranged from 18 to 3223 person-rem per reactor. However, the average annual. dose per nuclear plant worker of about 0.8 rem (NUREG-0713, Vol. 5) has not varied significantly during this period. The worker dose limit,. established by 10 CFR 20, is 3 rem per quarter, if the average dose over the worker lifetime is being controlled to 5 rem per year, or 1.25 rem per quarter if it is not. The wide range of annual collective doses experienced at PWRs in the United States results from a number of factors such as the amount of required mainte-nance and.the amount of reactor operations and in plant surveillance. Because these factors -can vary widely and unpredictably, it is impossible to determine in advance a specific year-to year annual occupational radiation dose for a particular plant over its operating lifetime. There may, on occasion, be a need for relatively high collective occupational doses, even at plants with radiation protection programs designed to ensure that occupational radiation doses will be kept ALARA. In recognition of the factors mentioned above, staff occupational dose estimates for environmental impact purposes for the South Texas plant are based on the assumption that each unit will experience the average annual occupational dose for PWRs to date. Thus, the staff has projected that the collective occupa-tional doses for each unit at the South Texas plant will be 510 person-rem, but annual collective doses could average as much as 3 times this value over the life of the plant. In addition to the occupational radiation exposures discussed above, during the period between the initial power operation of Unit 1 and the similar startup of Unit 2, construction personnel working on Unit 2 will potentially be exposed to sources of radiation from the operation of Unit 1. The applicant has estimated South Texas DES 5-20
that the integrated dose to construction personnel, over a period of about 29 months will be about 140 person-rem. This radiation exposure will result pre-dominantly from Unit I radioactive components and gaseous effluents from Unit 1. On the basis of experience with other PWRs, the staff finds that the applicant's estimate is reasonable. The average annual dose of about 0.8 rem per nuclear plant worker at operating PWRs has been well within the limits of 10 CFR 20. However, for impact evalua-tion, the staff has estimated the risk to nuclear power plant workers and com-pared it in Table 5.5 to published risks for other occupations. On the basis of these comparisons, the staff concludes that the risk to nuclear plant work-ers from plant operation is comparable to the risks associated with other occupations. In estimating the health effects resulting from both offsite (see Section 5.9.3.2) and occupational radiation exposures as a result of normal operation of this facility, the staff used somatic (cancer) and genetic risk estimators that are based on widely accepted scientific information. Specifically, the staff's estimates are based on information compiled by the National Academy of Sciences (NAS) Advisory Committee on the Biological Effects of Ionizing Radiation (BEIR I, 1972; BEIR III, 1980). The estimates of the risks to workers and the general public are based on conservative assumptions (that is, the estimates are probably higher than the actual number). The following risk estimators were used to estimate health effects: 135 potential deaths from cancer per million person-rem and 220 potential cases of all fo ; of genetic disorders per million person-rem. The cancer-mortality risk estimates are based on the " absolute risk" model described in BEIR I (NAS). Higher estimates can be developed by use of the " relative risk" model along with the assumption that risk prevails for the duration of life. Use of the " relative risk" model would produce risk values up to about four times greater than those used in this report. The staff re-gards the use of the " relative risk" model values as a reasonable ' upper limit of the range of uncertainty. The lower limit of the range would be zero because there may be biological mechanisms that can repair damage caused by radiation at low doses and/or dose rates. The number of potential cancers would be ap-proximately 1.5 to 2 times the number of potential fatal cancers, according to the 1980 report of the National Academy of Sciences Committee on the Biological Effects of Ionizing Radiation (NAS, BEIR III). Values for genetic risk estimators range from 60 to 1100 potential cases of all forms of genetic disorders per million person-rem (NAS, BEIR III). The value of 220 potential cases of all forms of genetic disorders is equal to the sum of the geometric means of the risk of specific genetic defects and the risk of defects with complex etiology. The preceding values for risk estimators are consistent with the recommendations of a number of recognized radiation protection organizations, such as the Inter-national Commission on Radiological Protection (ICRP, 1977), the National Coun-cil on Radiation Protection and Measurements (NCRP, 1975), the National Academy of Sciences (BEIR III), and the United Nations Scientific Committee on the Effects of Atomic Radiation (1982). South Texas DES 5-21
The risk of potentially fatal cancers in the exposed work-force population at .the South Texas facility is estimated as follows: multiplying the annual plant-worker population dose (about 1020 person-rem) by the somatic risk esti-mator, the staff estimates that about 0.14 cancer death may occur in the total exposed population. The value of 0.14 cancer death means that the probability of one cancer. death over the lifetime of the entire work force as a result of 1 year of facility operation is about 14 chances in 100. The risk of potential genetic disorders attributable to exposure of the work force is a risk Lorne by the progeny of the entire population and is thus properly considered as part of the. risk to the general public. (2) Public Radiation Exposure Transportation of Radioactive Materials The transpcrtation of " cold" (unirradiated) nuclear fuel to the reactor, of spent irradiated fuel from the reactor to a fuel reprocessing plant, and of solid radioactive wastes from the reactor-to a waste burial ground is considered in 10 CFR 51.52. The contribution of the environmental effects of such trans-portation to the environmental costs of licensing the nuclear power reactor is set forth in Summary Table S-4 from 10 CFR 51.52 (reproduced here as Table 5.4). The cumulative dose to the exposed population as summarized in Table S-4 is very small when compared with the annual collective dose of about 60,000 person-rems to this same population or 28,000,000 person-rem to the U.S. population from background radiation. Direct Radiation for PWRs Radiation fields are produced around nuclear plants as a result of radioactiv-ity within the reactor and its associated components, as well as a result of radioactive-effluent releases. Direct radiation from sources within the plant ' is due primarily to nitrogen-16, a radionuclide produced in the reactor core. 'Because the primary coolant of a PWR is contained in a heavily shielded area, dose rates in the vicinity of PWRs are generally undetectable, and less than 5 mrem per year at the site boundary. Low-level radioactivity storage containers outside the plant are estimated to make a dose contribution at the site boundary of less than 1% of that due to the direct radiation from the plant. Radioactive-Effluent-Releases: Air and Water Limited quantities of radioactive effluents will be released to the atmosphere
~
and to the hydrosphere during normal operations. Plant-specific radioisotope-release rates were developed on the basis of estimates regarding fuel performance and descriptions of the operation of radwaste systems in the FSAR, and by using the calculative models and parameters described in NUREG-0017. These radio-active effluents-are then diluted by the air and water into which they are released before they reach areas accessible to the general public. Radioactive effluents can be divided into several groups. Among the airborne effluents, the radioisotopes of the fission product noble gases, krypton and xenon, as well as the radioactivated gas argon, do not deposit on the ground nor are they absorbed and accumulated within living organisms; therefore, the South Texas DES 5-22
J noble gas effluents act primarily as a source of direct external radiation ' emanating from the effluent plume. Dose calculations are performed for the site boundary where the highest external radiation doses to a member of the general public as a result of gaseous effluents have been estimated to occur; these include the total body and skin doses as well as the annual beta and gamma air doses from the plume at the boundary location. Another group of airborne radioactive effluents--the fission product radio-iodines, as well as carbon-14 and tritium--are also gaseous but these tend to be deposited on the ground and/or inhaled into the body during breathing. For
; this class of effluents, estimates are made of direct external-radiation doses ! -from deposits on the ground,.and of internal radiation doses to total body, l thyroid, bone, and other organs from inhalation and from vegetable, milk, and 4
meat consumption. Concentrations of iodine in the thyroid and of carbon-14 in bone are of particular significance here. A third group of airborne effluents, consisting of particulates that remain after filtration of airborne
- effluents in the plant before release, includes fission products such as cesium and strontium and activated corrosion products >
such as cobalt and chromium. The calculational model determines the direct external radiation dose and the internal radiation doses for.these contaminants through the same pathways as-described above for the radioiodines, carbon-14, and tritium. -Doses from the particulates are combined with those of the radio-iodines, carbon-14, and tritium for comparison with one of the design objectives of Appendix I to 10 CFR 50. l The waterborne-radioactive-effluent constituents could include fission products such as nuclides of strontium and iodine; activation and corrosion products, such as nuclides of sodium, iron, and cobalt; and tritium as tritiated water. Calculations estimate the internal doses (if any) from fish consumption, from water ingestion (as drinking water), and from eating of meat'or vegetables raised near the site on irrigation water, as well as any direct external radiation
.from recreational use of the water near the point of discharge.
1 The release rates for each group of effluents, along with site-specific meteoro-logical and hydrological data,' serve as input to computer.ized radiation-dose models that estimate the maximum radiation dose that-would be received outside the facility by way of a number of pathways for individual members of the public, and for the general public as a whole. These models and the radiation-dose calculations are discussed in Revision 1 of Regulatory Guide 1.109, " Calculation of Annual Doses to Man From Routine Releases of Reactor Effluents for'the Purpose l of Evaluating Compliance With 10 CFR Part 50, Appendix I," and in Appendix 8 of this statement. Examples of site-specific dose assessment calculations and discussions of param-eters involved are given in Appendix D. Doses from all airborne effluents ex-j cept the noble gases are calculated for individuals at the location (for example, the site boundary, garden, residence, milk cow or goat, and meat animal) where the highest radiation dose to a member of the public has been established from all applicable pathways (such as ground deposition, inhalation, vegetable con-sumption, cow milk consumption, or meat consumption. ) Only those pathways associated with airborne effluents that are known to exist at a single location are combined to calculate the total maximum exposure ~to an exposed individual.
? Pathway doses associated with liquid effluents are combined without regard to
- j. South Texas DES 5-23
l any single location, but they are assumed to be associated with maximum expo-sure of an individual through other than gaseous-effluent pathways. 5.9.3.2 Radiological Impact on Humans Although the doses calculated in Appendix 0 a~ re based primarily on radioactive-waste treatment system capability and are below the 10 CFR 50, Appendix I design objective values, the actual radiological impact associated with the operation of the facility will depend, in part, on the manner in which the radioactive-waste treatment system is operated. On the basis of its evaluation of the po-tential performance of the ventilation and radwaste treatment systems, the staff has concluded that the systems as now proposed are capable of controlling efflu-ent releases to meet the dose-design objectives of Appendix I to 10 CFR 50, l
. with the existing pathways for exposure of the public.
Operation of the South Texas facility will be governed by operating license Technical Specifications that will be based on the dose-design objectives of Appendix I to 10 CFR 50. Because these design-objective values were chosen to permit flexibility of operation while still ensuring that plant operations are ALARA, the actual radiological impact of plant operation may result in doses close to the dose-design objectives. Even if this situation exists, the indi-vidual doses for the person subject to maximum exposure wi11 still be very small when compared with natural background doses'(*100 mrem per year) or the
; dose limits (500 mrem per year, total body) specified-in 10 CFR 20 as consistent with considerations of the health and safety of the public. As a result,-the staff' concludes that there will be no measurable radiological impact on any member of the public from routine operation of th9 South Texas facility.
Operating standards of 40 CFR 190 (the EPA environmental radiation protection standards for nuclear power plant operations) specify that the annual dose equivalent must not exceed 25 mrem to the whole body, 75 mrem to the thyroid, and 25 mrem to any other organ of any member of the public as the result of exposures to planned discharges of radioactive materials (radon and its daugh-ters excepted) to the general environment from all uranium-fuel-cycle opera-tions'and radiation from these operations that can be expected to affect a given individual. The staff concludes that under normal operations the South Texas facility is capable of operating within these standards, with the exist-ing pathways for exposure of the public.
- i. The radiological doses and dose commitments resulting from a nuclear power plant l are well known and documented. Accurate measurements of radiation and radio-active contaminants can be made with a very high sensitivity so that much smaller amounts of radioisotopes can be recorded than can be associated with any pos-sible observable ill effects. Furthermore, the effects of radiation on living systems have for decades been subject to intensive investigation and considera-tion by individual scientists are well as by select committees that have occa-sionally been constituted to objectively and independently assess radiation dose effects. Although, as in the case of chemical contaminants, there is debate about the exact extent of the effects of very low levels of radiation that result from nuclear power plant effluents, upper bound limits of deleterious effects are well established and amenable to standard methods of risk analysis. Thus l
the risks to the maximally exposed member of the public outside of the site l South Texas DES 5-24
boundaries or to the total population outside of the boundaries can be readily calculated and recorded. These risk estimates for the South Texas facility are presented below. The risk to the maximally exposed individual is estimated by multiplying the risk estimators presented in Section 5.9.3.1(1) by the annual dose-design objec-tives for total-body radiation in 10 CFR 50, Appendix I. This calculation re-sults in a risk of potential premature death from cancer to the individual from exposure to radioactive effluents (gaseous or liquid) from 1 year of reactor operations of less than 1 chance in 1 million.* The risk of potential pre-mature death from cancer to the average individual within 80 km (50 mi)'of the reactors from exposure to radioactive effluents from the reactors is much less than~the risk to the maximally exposed individual. These risks are very small in comparison to cancer incidence from causes unrelated to the operation of the South Texas facility. Multiplying the annual dose to the general public population of the United States from exposure to radioactive effluents and transportation of fuel and waste from the operation of this facility (that is, 8? person-rem) by the preceding } somatic risk estimator, the staff estimates that about 0.01 cancer death may occur in the exposed population. The significance of this risk can be deter-mined by comparing it to the total projected incidence of 462,000 cancer deaths i in the population of the United States in 1985. Multiplying the estimated population of the United States for the year 2010 (s280 million persons) by the current incidence of actual cancer fatalities (*20%), about 56 million cancer deaths are expected (American Cancer Society, 1985). For purposes of evaluating the potential genetic risks, the progeny of workers are considered members of the general public. However, according to paragraph 80 of ICRP, 1977, it is assumed that only about one-third of the occupational radiation dose is received by workers who have offspring after the workers' radiation exposure. Multiplying the sum of the dose to the population of the United States from exposure to radioactivity attributable to 'the normal annual operation of the plant (that is, 82 person rem), and the estimated dose from occupational exposure (that is, one-third of 1]20 person-rem) by the preceding genetic risk estimators, -the staff estimates that about 0.09 potential genetic disorder maj occur in all future generations of the exposed population. Because BEIR III indicates that the mean persistence of the two major types of genetic disorders is about 5 generations and 10 generations, in the following analysis the risk of potential genetic disorders from the normal annual operation of the plant is conservatively compared with the risk of actual genetic ill health in the first 5 generations, rather than tne first 10 generations. Multiplying the estimated population within 80 km of the plant (s320,000 persons in the year 2010) by the current incidence of actual genetic ill health in each generation (s11%), about 180,000 genetic abnormalities are expected in the first 5 genera-tions of the population within 80 km of the South Texas facility (8EIR III).
-The risks to the general public from exposure to radioactive effluents and transportation of fuel and wastes from the annual operation of the facility are *The risk of ' potential premature death from cancer to the maximally exposed individual from exposure to radiciodines and particulates would be in the same l range as the risk from exposure to the other types of effluents.
South Texas DES 5-25
very small fractions of the 'stimated normal incidence of cancer fatalities and genetic abnormalities. On the basis of the preceding comparison, the staff concludes that the risk to the public health and safety from exposure to radio-activity associated with the normal operation of the facility will be very small. 5.9.3.3 Radiological Impacts on Biota Other Than Humans Depending on the pathway and the radiation source, terrestrial and aquatic biota will receive doses that are approximately the same or somewhat higher than humans receive. Although guidelines have not been established for acceptable limits for radiation exposure to species other than humans, it is generally agreed that the limits established for humans are sufficiently protective for other species. Although the existence of extremely radiosensitive biota is possible and in-aeased radiosensitivity in organisms may result fro.a environmental interactions with other stresses (for example, heat or biocides), no biota have yet been discovered tnat show a sensitivity (in terms of increased morbidity or mortality) to radiation exposures as low as those expected in tne area surrounding the facility. Furthermore, at all nuclear plants for which radiation exposure to biota other than human.s has been analyzed (31aylock, 1976), there have been no cases of exposure that can be considered significant in terms of the public that are permitted by 10 CFR 20. Inasmuch as the 1972 BEIR Report (BEIR I) concluded that evidence to date indicated that no other living organisms are very much more radiosensitive than humans, no measurable radiological impact on populations of bi ua is expected as a result of the routine operation of this facility. 5.9,3.4 Radiological Monitoring Radic!ogical environmental monitoring programs are established to provide data where there are measuraable levels of radiation and radioactive materials in the site environs and to show that in many cases no detectable levels exist. Such monitoring programs are conducted to verify the effectiveness of systems in the plant used to control the release of radioactive materials and to ensure that unanticipated buildups of radioactivity will not occur in the environment. Secondarily, the environmental monitoring programs could identify the highly unlikely existence of releases of radioactivity from unanticipated release points that are not monitored. An annual surveillance (land census) program will be established to identify changes in the use of unrestricted areas to provide a basis for modifications of the monitoring programs or of the Technical Specifi-cation conditions that relate to the control of doses to individuals. These programs are discussed generically in greater detail in Regulatory Guide 4.1, Revision 1, " Programs for Monitoring Radioactivity in the Environs of Nuclear Power Plants," and in the Radiological Asses:; ment Branch Technical Position, Revision 1, "An Acceptable Radiological Environmental Monitoring Program." (); Preoperational The oreoperational phase of the monitoring program should provide for the 7ea-surement of background levels of radioactivity and radiation and their variations South Texas DES 5-26
along the anticipated important pathways in the areas surrounding the facility, for the training of personnel, and for the evaluation of procedures, equipment, and techniques. The applicant proposed a radiological environmental monitoring program to meet these objectives in the ER-CP, and it was discussed in the FES-CP. The current program is in ER-OL Section 6.1.5 and is summarized here in Table 5.6 The applicant stated that this preoperational monitoring program began in July 1985 and will continue until issuance of tne operating license, at which time the operational radiological monitoring program will commence. The staff has reviewed the preoperational environmental monitoring plan of the applicant and finds that it is acceptable as presented. (2) Op_erational The operational, offsite radiological-monitoring program is conducted to provide data on measurable levels of radiation and radioactive materials in the site environs in accordance with 10 CFR 20 and 50. It assists and provides backup support to the effluent-monitoring program recommended in Regulatory Guide 1.21,
" Measuring, Evaluating and Reporting Radioactivity in Solid Wastes and Releases of Radioactive Materials in Liquid and Gaseous Effluents From Light-Water Cooled Nuclear Power Plants."
The applicant states that the operational program will, in essence, be a contin-uation of the preoperational program described above, with some periodic adjust-ment of sampling frequencies in expected critical exposure pathways. The proposed operational program will be reviewed before plant operation. Modi-fication will be based on anomalies and/or exposure pathway variations observed during the preoperational program. The final operational monitoring program proposed by the applicant will be re-viewed in detail by the staff, and the specifics of the required monitoring program will be incorporated into the operating license radiological Technical Specifications. 5.9.4 Environmental Impacts of Postulated Accidents The staff has considered the environmental impact of radiological releases due to postulated accidents, including those involving core melt and loss of con-tainment integrity at South Texas Project Units 1 and 2. In another document, the staff's Safety Evaluation Report (NUREG-0781), the staff analyzed a number of accidents, called design-basis accidents, for the purposes of determining (1) performance requirements for plant engineered safety features and (2) site suitability. The discussion that follows summarizes the staff's evaluation of the accident risks (defined as probability times consequences) associated with operating the South Texas facility. At'some of the 98 U.S. nuclear power plants currently holding operating licenses, accidents have resulted in radioactive releases to the environment. No radiation fatality or injury to any member of the public has been attributed tc these accidents. On the basis of population exposure estimates, the 1979 Three Mile ' Island Unit 2 accident (the worst in U.S. commercial nuclear power plant history) South Texas DES 5-27
could produce about one additional statistical fatal cancer over the lifetime of the exposed population. By comparison, approximately half a million fatal cancers are expected to develop in this same group. The evidence of low injury and death can be ascribed to various operational and design safety features which (as documented in the Final Safety Analysis Report) minimize fission product releases to the environment in the event of a reactor accident. They include strong containment and pressure vessels to contain the radioactive fission products, emergency core cooling systems, and containment spray systems to help control containment pressures and remove radioactive fis-sion products from the containment atmosphere. If, however, some of these fea-tures fail and a release occurs, the resulting radiation exposures to the popu-lation would depend on the release characteristics, meteorological conditions, separation distance, exposure duration, emergency response, and radiation shielding factors. Numerical estimates of these characteristics are used as input data from the CRAC 2 (Calculation of Reactor Accident Consequences) com-puter program used for the radiological consequences analysis. The accident assessment methodology used by the staff was adapted from the Reactor Safety Study (U.S. AEC, WASH-1400, 1975) (reclassified as U.S. NRC, NUREG-75/014) using the principles described in the Probabilistic Risk Assess-ment Handbook (NUREG/CR-2300). The accident release calculations for the South Texas facility were generated frcm both recent research work on source terms (Case 1), and from the 1980 understanding of fission product releases (Case 2). The two cases have been assessed to provide a perspective on risks that demonstrates the impacts of a better understanding of fission product re-
~
leases, chemistry and attenuation under accident conditions. Appendix G sum-marizes the characteristics of the release categories corresponding to each case. The result and detailed discussions of the calculations of dose, health, and socioeconomic impacts for the ".,r+h Texas site are presented in Appendix F. The more noteworthy health risks from mtential reactor accidents at the South ' Texas site are small as shown in Tabic c.5 of Appendix F. These values were obtained by an analysis of all of the release categories, their probabilities, and their corresponding radiological consequences. The accident latent cancer fatality risks averaged over a 50-mi radius of the site are calculated to be 2.8 x 10 8 per reactor year per person for Case 1 (1985), and 3.2 x 10 8 per reactor year per person for Case 2 (1980). These values are neg i to the cancer fatality risk per individual per year of 1.9 from x 10-}igible all other relat ve sources (American Cancer Society, 1985). Similarly, the individual early fatal-ity risk to the population in the vicinity of.the plant from both cases comprises less than one-tenth of 1% of the combined risks of accidental death from other causes such as automobile accidents, falls, and drownings. The average value of early fatality risk for Case 1 is about two orders of magnitude lower than it is for Case 2. This difference is due to the threshold nature of the early fatality risk. The latent cancer fatality risk, on the other hand, varies more linearly with the source term since the health effects are related to the total population dose measured over longer time periods. In relation to other plants, the calculated risks of latent cancer fatality and early fatality The descrip-for the South Texas Unit 1 or Unit 2 are lower than the average. tion of other environmental risks such as accidental population exposures and costs of protective actions and decontamination are discussed in Appendix F. South Texas DES 5-28
~ - _ - - _ _ . -.. . . _- - - . _ _ - _ _
For accidents that result in the release of substantial quantities of radio- ; active isotopes, the number of accident fatalities and injuries can be reduced by taking protective actions such as evacuation and medical treatment. One measure of the sensitivity of risk to protective action can be determined by comparing Figure F.5 of Appendix F and Figure H.1 of Appendix H. The difference between Figure F.5 (with evacuation) and Figure H.1 (without evacuation but with relocation after 24 hours) indicates the effects of evacuation on early fatalities within a 10-mile plume exposure pathway. The sensitivity of early , fatalities estimates to supportive (specialized hospital diagnosis and treatment) versus nonsupportive medical treatment is seen by comparing Figures F.5 (sup-portive) and H.2. (nonsupportive). The interpretation of these results shculd be made with full understanding of the uncertainties associated with the risk analysis. There are large uncer-tainties in the results of risk analysis,, including those attributed to the likelihood of accident sequences, containment failure modes, source terms asso- , ciated with release categories, and the environmental consequence estimates. The primary contributions to the uncertainties are discussed'in Appendix F. Conclusion The potential impact of radioactive releases to the environment surrounding the South Texas site, including those severe accident sequences that could lead to core melting, have been considered. Included in the evaluation are radiation l exposures in the environment and to the population, the probabilities of acci-dents, the risks of adverse health effects, and socioeconomic consequences.
.The staff's analyses indicate that the impacts of such accidents could be severe, but the severity is offset by such a low probability of occurrence that, over-all, the risks are small.
This review has not revealed the potential for any new accident sequences that have not been previously identified for other Westinghouse PWRs with large dry l containments. A comparison of the other staff-reviewed PWR risk studies for j plants of similar characteristics to the South Texas plants indicates that the l variation is rather small and, therefore, the severe accident risk estimates l for the South Texas plants are expected to be comparable and perhaps lower than other plants reviewed. On the basis of the foregoing material, the staff has concluded that there are no rpecial or unique accident-related circumstances about the South Texas site, the two units, and the environs that warrant consideration of accident preven-tion or mitigation alternatives. 5.9.5 -Site-specific characteristics I j The NRC's reactor site criteria, 10 CFR 100, require that every power reactor
- site have certain characteristics that tend to reduce the risk and potential impact of accidents. The discussion that follows briefly describes the South Texas site characteristics and how they meet these requirements.
First, the site has an exclusion area as required by 10 CFR 100, located within the 12,300 acres owned by Houston Lighting & Power Company. The exclusion area for the South Texas Project is oval shaped, encompassing both Units 1 and
- 2. The minimum distance from the center of the Unit 1 containment building to i
South Texas DES 5-29 _..m .- ,--. _,- ---
the exclusion area boundary is 1430 m (4692 ft). No people reside within the exclusion area. The applicant owns and controls all of the land and mineral rights within the exclusion area. Therefore, the applicant has the authority required by 10 CFR 100 to determine all activities in this area. The only activities unrelated to Unit 1 operation that occur within the exclusion area includes activity associated with the maintenance and operation of the proposed high-voltage direct-current terminal, and the construction of Unit 2. There
-are no railroads, highways, or waterways traversing the exclusion area. In case of an emergency, arrangements have been made to limit access and control the activity and evacuation of anyone in the exclusion area.
Second, beyond and surrounding the exclusion area is a low population zone (LPZ), also required by 10 CFR 100. The LPZ for the South Texas Project is a circular area.with a 4828 m (15,480 ft) radius measured from a point 93 m west of the center of the Unit 2 containment building. The area within the LPZ is sparsely populated and situated about 23 ft above mean sea level. It is generally flat, consisting mostly of agricultural land, with some wooded areas and very little , industrial development. Within this zone, the applicant must ensure that there is a reasonable probability that appropriate protective measures could be taken on behalf of the residents and other members of the public in the event of a serious accident. The applicant has indicated that there were about 9 persons residing in the LPZ in 1985, and projects the population to increase to about
~
20 by the year 2030. In case of a radiological emergency, the applicant has. made arrangements to carry out protective actions, including evacuation of per-sonnel in the vicinity of the South Texas Project. Third, 10 CFR 100 also requires that the distance from the reactor to the nearest boundary of a densely populated area containing more than about 25,000 residents
, be at least one and one-third times the distance from the reactor to the outer-boundary of the LPZ. Since accidents of greater potential hazards than those commonly postulated as representing an upper limit are conceivable, although highly improbable, it was considered desirable to add the population center distance requirements in 10 CFR 100 to provide for protection against excessive exposure doses to people in large centers. Bay City, Texas, located about 19.3 km (12 mi) north-northeast of the plant with a projected population greater than 35,000 by 2030, is the nearest population center to the site. The distance
, from the site to Bay City is at least one and one-third times the distance to the outer boundary of the LPZ. There are no major cities within 80 km (50 mi)
'of the site. Except for Lake Jackson City which is 67.6 km (42 mi) east-
, northeast of the site with a 1980 population of 19,102, Bay City is essentially the largest populated area in the vicinity of the plant with a 1980 population of 17,837 persons. The population density within 48 km (30 mi) of the site when the plant is scheduled to go'into operation (1990) is projected to be~ 2 10 persons /km2 (26 persons /mi2), and is not expected to exceed 18 persons /km (47 persons /mi2) during the life of the plant. The safety evaluation of the South Texas Project has also included a review l of potential external hazards, i.e., activities off site that might adversely affect the operation of the plant and cause an accident. This review encom-passed nearby industrial, transportation, and military facilities that might create explosive, missile, toxic gas, or similar hazards. The risk to the South
-Texas facility from such hazards has been found to be negligibly small. A more detailed discussion of the compliance with the Commission's siting criteria and South Texas DES 5-30
the consideration of external hazards will be given in the staff's Safety Eval-uation Report. 5.10 Impacts From the Uranium Fuel Cycle The uranium fuel cycle rule, 10 CFR 51.51,. reflects the latest information rela-tive to the reprocessing of spent fuel and to radioactive waste management as discussed in NUREG-0116, " Environmental Survey of the Reprocessing and Waste Management Portions of the LWR Fuel Cycle," and NUREG-0216, which presents staff responses to comments on NUREG-0116. The rule also considers other environmen-tal factors of the uranium fuel cycle, including aspects of mining and milling, isotopic enrichment, fuel fabrication, and management of low- and high-level wastes. These are described in the U.S. AEC report WASH-1248, " Environmental Survey of the Uranium Fuel Cycle." The staff was also directed.to develop an explanatory narrative that would convey in understandable terms the signifi-cance of releases in the table. The narrative was also to address such impor-tant fuel cycle impacts as environmental dose commitments and health effects, socioeconomic impacts, and cumulative impacts,' where these are appropriate for generic treatment. A proposed explanatory narrative was published in the Federal Register on March 4, 1981 (46 FR 15154-15175). Appendix C to this re-port contains a number of sections that address those impacts of the fuel cycle
- supporting a light-water reactor that reasonably appear to have significance for 4
individual reactor licensing sufficient to warrant attention for. NEPA purposes. Table S-3 of the final rule is reproduced here in its' entirety as Table 5.3.* Specific categories of natural resource use included in the table related to land use, water consumption and thermal effluents, radioactive releases, burial of transuranic and high- and low-level wastes, and radiation doses from trans-portation and occupational exposures. The contributions in the table for repro-cessing, waste management, and transportation of wastes are maximized for either of the two fuel cycles (uranium only and no recycle)--that is, the cycle is i used that results in the greater impact. Appendix C to this report contains a description of the environmental impact assessment of the uranium fuel cycle as related to the operation of the South Texas facility. The environmental impacts are based on the values given in Table S-3 (Table 5.3) and on an analysis of the radiological impact from radon-222 and technetium-99 releases. The staff has determined that the envi-ronmental impact of this' facility on the population of the United States from radioactive gaseous and liquid releases (including radon and technetium) is negligible, because impact of the uranium fuel cycle is very small when com-pared with the impact of the natural background radiation. In addition, the nonradiological impacts of the uranium fuel cycle have been found to be acceptable. 5.11 recommissioning The purposes of decommissioning are (1) to safely remove nuclear facilities from service and (2) to remove or isolate the associated radioactivity from the l
*The U.S.' Supreme Court has upheld the validity of the S-3 rule in Baltimore Gas & Electric Co., et al. v. Natural Resources Defense Council, Inc.,
No. 82-524, issued June 6, 1983, 51 U.S. Law Week, 4678. South Texas DES 5-31
0 I environment so that the part of the facility site not permanently committed can be released for other uses. Alternative methods of accomplishing these purposes i and the environmental impacts of each method are discussed in NUREG-0586. ' Since 1960, 68 nuclear reactors--including 5 licensed reactors that had been used for the generation of electricity--have been or are in the process of being decommissioned. Although, to date, no large commercial. reactor has undergone decommissioning, the broad base of experience gained from smaller facilities is generally relevant to the decommissioning of any type of nuclear facility. Radiation doses to the public as a result of end-of-life decommissioning activ-ities should be small; they will come primarily from the transportation of waste to appropriate repositories. Radiation doses to decommissioning workers should be well within the occupational exposure limits imposed by regulatory requirements. The NRC staff is currently conducting rulemaking proceedings that will develop a more explicit overall policy for decommissioning commercial nuclear. facilities Specific licensing requirements are being considered that include the develop-ment of decommissioning plans and financial arrangements for decommissioning nuclear facilities. The staff's estimate of decommissioning costs is provided in Section 6.4.2. 5.12 Noise The staff reviewed the various sources of potential noise impact to the commu-nity in the vicinity of the South Texas site. The largest potential sources are the makeup water pump station and the onsite transformers. The applicant ] did not provide quantitative noise data for the site and vicinity. The pumps are not near occupied areas and will not be operated often. There-fore, the impact of noise from this source will be negligible. The makeup water pump station on the Colorado River is located approximately 0.5-1.0 mile (0.6-1.6 km) downstream of several cabins used by fishermen and hunters at var-ious times during that year. The pump station is expected to operate only oc-casionally during the operating life of the South Texas Project. The transformers are also far from inhabited' areas. The residence nearest to the transformer is located approximately 4,570 m (15,000 ft) southwest of the site (FSAR, Section 2.1.3). The staff does not believe that transformer noise levels will'be distinguishable from background'by residents at this remote location. 5.13 Environmental Monitoring 5.13.1 Terrestrial Monitoring In the FES-CP, the staff concluded that the direct impacts of plant operation on the terrestrial biota of the site will be minor. This conclusion remains valid, and no general nonradiological monitoring is required, although the applicant's plan to continue monitoring at least for waterfowl and bald eagles is commended. South Texas DES 5 _ _ _ _ ._ -- . _ . - _ _ - _ _. ._ - - _ _ _ _
The FES-CP expressed concern that.possible changes in freshwater inflow to the marsh ~ south of the site, occurring as a result of plant operation, could adversely affect the marsh. In addition, the study (NUS,1976c) conducted for the applicant indicated that changes in the quantity and quality of nutrients and dissolved solids reaching the upper marsh could affect the composition of plant communities and primary and secondary productivity. The FES-CP required preoperational monitoring in the marsh to furnish data necessary for maintenance of an adequate marsh habitat. The applicant addressed these concerns in the ER-OL by proposing to monitor indicator plant species to detect changes in salinity in the marsh. The proposed program involved annual fall surveys to ascertain, by visual estimation, the relative abundance of four plant species which are apparently stenohaline (plants that grow only within a narrow range
-of salinity). The species proposed to be monitored were softstem bulrush (Scirpus californicus), marsh millet (Zizaniopsis miliacea), hornwort (Cerato phyllum demersum), and widgeon grass (Ruppia maritima). The applicant was
- unable to fully implement this program because access to the marsh has been prohibited by the landowner, but has continued remote sensing of the upper marsh.
Despite the more recent estimates of only slightly reduced freshwater input, the staff concurs that operational monitoring would show better whether the marsh is remaining in its present state. However, because the impacts are expected to be minor and because the marsh is privately owned and subject to degradation from many sources other than the power plant, requirement of an operational monitoring program is not justified. 5.13.2 Aquatic Monitoring The certifications and permits required under the Clean Water Act provide the mechanisms for protecting water quality and aquatic biological resources in the vicinity of operating power plants. Operational monitoring of effluents will be required by the NPDES Permit No. TX0064947 issued by the USEPA (see Appen-dix E of this environmental statement). The NRC will rely on the USEPA, and the State of Texas, under authority of the Clean Water Act for the protecticn of water quality and aquatic biota, and for any associated nonradiological moni-toring that may be required during plant operation. An Environmental-Protection Plan will be included as Appendix 8 to the South Texas Project operating license. The plan will include requirements for prompt reporting by the applicant of important events that potentially could result in significant environmental impacts causally related to station operation (for example: fish kills, mortality of any species protected by the Endangered Species Act of 1973 as amended, an increase in nuisance organisms or condi-tions, or any unanticipated or emergency discharge of waste water or chemical substances). 5.13.3 Atmospheric Monitoring The onsite meteorological measurements program described in FES-CP Section 6.1.2 remains essentially unchanged. This program provided 4 years of data (Janu-
~
ary 1974 through December 1977) for use in the atmospheric dispersion assessment oescribed in Appendix D of the statement. Data recovery for the 4 year period of record described above was about 98L Although the applicant has indicated that the system accuracy for analog recording of vertical temperature difference South Texat CES 5-33
i l I (an indicator of atmospheric stability) is not within the specification pre-sented in Regulatory Guide 1.23, "Onsite Meteorology Programs," the data col-lected appear reasonable. The 4 year period of record is expected to reason-ably reflect diurnal, seasonal, and annual airflow and stability patterns. The applicant upgraded the meteorological data collection system in July 1984, for use during plant operation, including installation of a 10-m (32.8-ft) backup tower. The staff is evaluating these upgrades. The fog monitoring program originally described by the applicant, included proposed sampling stations located northwest of the reservoir on FM521 and southeast of the reservoir along the blowdown pipeline. The applicant also indicated that the fog monitoring program would begin 1 year before plant operations and continue for a 1 year period after continued operation of both units. 5.14 References American Cancer Society, " Cancer Facts and Figures," 1985. Bankoske, J. W., H. B. Graves, and G. W. McKee. "The Effects of High Voltage Electric Lines on the Growth and Development of Plants and Animals," in Proceedings of the First National Symposium on Environmental Concerns in Rights-of-Way Management, Mississippi State University,1976. Battelle Columbus Laboratory, BMI-2104, "Radionuclide Release Under Specific LWR Accident Conditions," July 1984. Blaylock, 8. G. , and J. P. Witherspoon, " Radiation Doses and Effects Estimated for Aquatic Biota Exposed to Radioactive Releases from LWR-Fuel-Cycle Facil-ities," in Nuclear Safety, 17:351, 1976. Brookhaven National Laboratory, Technical Report A-3804, " Estimates of Steam Spike and Pressurization Loads for a Subatmospheric Containment," July 1985 (in preparation). Houston Lighting and Power Company, " South Texas Units 1 & 2, Final Safety Analysis Report," July 1978. i
-- , " Environmental Report, Operating License Stage," South Texas Project, Units 1 and 2, 1978. ~ International Commission on Radiological Protection (ICRP), " Recommendations of-the International Commission on Radiological Protection," ICRP Publication 26, January 1977.
l Lyon, W. C. (NRC), Memorandum to B. W. Sheron, " Observations From Trip to the South Texas Project in Regard to Severe Accidents," August 5, 1985. McAden, D. C. , G. N. Greene, and W. B. Baker, Jr. , Report #1, " Colorado River Entrainment and Impingement Monitoring Program. Phase Two Studies--July 1983-June 1984," Ecology Division, Environmental Protection Department, Houston-Lighting and Power Co., Houston, Texas, October 1984. South Texas DES 5-34
-- , Report #2, " Colorado River Entrainment and. Impingement Monitoring-Program.
Phase Two Studies--July-December 1984. Ecology Division, Environmental Protec-tion Department, Houston Lighting and Power Co. , Houston, Texas,- April 1985. Meyer, J. F., and W. T. Pratt, " Direct Testimony Concerning Commission Question 1, Indian Point Hearings," Docket Numbers 50-247 and 50-286, 1983. Miller, M. W., and G. E. Kaufman, "High Voltage Overhead," Environment 20(1):6-36, 1978. Millstone Point Co., " Millstone 3 Final Safety Analysis Report," May 1984. National Academy of Sciences / National Research Council, Advisory Committee on the Biological Effects of Ionizing Radiations (BEIR I), "The Effects on Population of Exposure to Low Levels of Ionizing Radiation," November 1972.
-- , BEIR III, "The Effects on Populations'of Exposure to Low Levels of Ioniz-ing Radiation: 1980," July 1980. 'NUS Corporation. "A Report on the Ecology of the Lower Colorado River--
Matagorda Bay Area of Texas, June 1973 through July 1974," September 1974.
-- , R-32-00-12/76-676, " Final Report, Colorado River Entrainment Monitoring Program. Phase One Studies--April 1975-March 1976," 1976b.
-- , R-32-00-12/76-656, " Final Report, Little Robbins Slough, Aquatic Ecological Studies, April 1975--March 1976," December 1976c.
Oak Ridge. National Laboratory, ORNL/TM-6165, Publication No. 2067, " Technical and Environmental Aspects of Electric Power Transmission," Environmental
~ Sciences Division, Oak Ridge, Tennessee, 1985.
Power Authority of New York, " Indian Point Unit 3, Final Safety Analysis Report," Docket 50-286, December 1970. Rural Electrification Administration, " Electrostatic and Electromagnetic Effects of Overhead Transmission Lines," 1976. Sendaula, M., D. W. Hilson, R. C. Myers, L. G. Aikens, and B. J. Woolery,
" Analysis of Electric and Magnetic Fields Measured Near TVA's 500-kV Transmission Lines," in Proceedings of the IEEC/ PES 1983 Summer Meeting, Los Angeles, California, July 17-22, 1983, Publication No. 83 SM 463-7, 1983.
Stout, I. J., and G. W. Cornwell, " Nonhunting Mortality of Fledged North American Waterfowl," Journal of Wildlife Management, 40:681-693, 1976. United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR),
" Ionizing Radiation: Sources and Biological Effects," 1982.
U.S. Atomic Energy Commission WASH-1248, " Environmental Survey of the Uranium Fuel Cycle," April 1974.
-- , WASH-1400 (see U.S. Nuclear Regulatory Commission, NUREG-75/014).
South Texas DES 5-35
. - - , - - , . -- -.-v -.- - , - - - . . , , - - - - - - , , - - - - - . -
U.S. Bureau of Labor. Statistics, " Occupational Injuries and Illness in the United States by Industry,1975," Bulletin 1981, 1978. U.S. Department of Energy, " Electrical and Biological Effects of Transmission Lines: A Review," Bonneville Power Administration, Portland, Oregon, August 27, 1982. U.S. Department of Health, Education, and Welfare, " Report on Occupational
' Safety and Health," May 1972.
~
U.S. Nuclear Regulatory Commission, NUREG-75/014 (formerly WASH-1400),
" Reactor Safety Study," October 1975.
-- , NUREG-0017, " Calculations of Release of Radioactive Materials in Gaseous and Liquid Effluents for Pressurized Water Reactors (PWR-GALE Code)," April 1976.
-- ,;NUREG-0586, " Draft Generic Environmental Impact Statement on Decommissioning of Nuclear Facilities," January 1981.
-- , NUREG-0713 (Vol. 5), " Occupational Radiation Exposure at Commercial Nuclear Power Reactors--1983 Annual Report," March 1985.
-- , NUREG-0773, "The Development of Severe Reactor Accident Source Term:
1957-1981," November 1982.
-- , NUREG-0850 (Vol. 1), " Preliminary Assessment of Core Melt Accidents at the Zion and Indian Point Nuclear Power Plants and Strategies for Mitigating Their Effects," November 1981. -- , NUREG-0956, " Reassessment of the Technical Bases for Estimating Source Terms," Draft Report for Comment, July 1985. -- , NUREG/CR-2300 (Vol. 1), "PRA Procedures Guide. A Guide to the Performance of Probabilistic Risk Assessments for Nuclear Power Plants," January 1983. -- , NUREG/CR-4143, " Review and Evaluation of the Millstone Unit 3 Probabilis-tic Safety Study: Containment Failure Modes, Radiological Source-Terms and Off-Site Consequences," July 1985.
Virginia Electric & Power Co., "Surry Units 1 & 2 Final Safety Analysis Report," December 1969. ' Wilkinson, D. L. , " Remote Sensing Survey of the Vegetation of Little Robbins Slough Wetlands, Matagorda County, Texas, 1982," Final Report, Biological Con-sulting Services, College Station, Texas, for Houston Lighting & Power Co., Houston, Texas, November 1984. Wilson, R., and E. S. Koehl, " Occupational Risks of Ontario Hydro's Atomic Radia-tion Workers in Perspective," presented at' Nuclear Radiation Risks, A Utility-Medical Dialog, sponsored by the International Institute of Safety and Health
- l. in Washington, D.C., September 22-23, 1980.
-South Texas DES 5-36
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il t \ l LE0t4D ' A'a'"?"Jn ., . . . k':';::,"L-, ' _'; e . .. o Mo" Figure 5.1 100 year floodplains Source: FSAR Figure '_.4.1-3 South Texas DES 5-37
p Table 5.1 Cycle makeup water demineralizer waste flow composition E
=r y Range of g means for 3 g Regenerative replicates
- Reservoir Reservoir Reservoir' .TDWR**
+
.a pH and chemical waste ambient river maximum, day maximum,1 yr maximum, 40 yr requirements-
! E pH*** 6.0-8.0' 7.7-8.7 -- -- -- 6.7-8,5 Na,' ppm 1027 '42-46 1.43 x 10 3 0.52 20.90 None Ca, ppm 22.4 47-82 3.12 x 10 5 1.14 x 10 2 0.48 None Mg, ppm 5.8 14-23 8.08 x 10 6 2.95 x 10 3 '0.12 None HCO 3 , ppm 122 149-204 1.70 x 10 4 6.21 x 10 2 2.60 None C1, ppm 118.6 58-83 1.65 x 10 4 6.04 x 10 2 2.53 None l SO4 , ppm 1753 32.7-3913 2.44 x 10 3 0.89 37.40 None i SiO2 , ppm 28.8 17.5-158.7 4.01 x 10 5 1.47 x 10 2 0.61 None Total dissolved 3078 -- 4.29 x 10 3 1.57 65.66 None l solids, ppm
*From data collected during 1973 at Station 2.
** Texas Department of Water Resources.
***Following neutralization.
Source: ER-OL, Table 5.4-1
T Table 5.2 Estimate of major STP property tax payments by jurisdiction-- g Houston Lighting & Power Company and Cent N1 Power & Light Company g Taxing Authority 1988 1989 1990 1991 _ 1992 1993 1994 s vi Matagorda County: a General Fund $5.332.000 $ 5.625.000 $ 5.722.000 $ 5.722.000 $ 5.722.000 $ 5.722.000 $ 5.722.000 m Navigation District No. 1 2.312.000 2.439.000 2.481.000 2.481.000 2.481.000 2.481.000 2.481.000
" Palacios Seavall Cosmaission 2.307.000 2.434.000 2.476.000 2.476.000 2.476.000 2.476.000 2.476,000 Hospital District 2.136.000 2.254.000 2.293.000 2.293.000 2.293.000 2.293.000 2.293.000 Special Ad Valores (Itoad) 1.557.000 1.643.000 1.671.000 1.671.000 1.671.000 1.671.000 1.671.000 Drainage District No. 3 1.495.000 1.577.000 1.604,000 1.604.000 1.604.000 1.604.000 1.604,000 Palacios Independent School District 11.651,000 12.291.000 12.503,000 12.503.000 12,503.000 12.503.000 12.503.000 Estimated Total Taxes $26.790,000 $28.263.000 $28,750,000 $28,750.000 $28,750.000 $28,750,000 $28.750.000 Assuuptionst m (1) Taxes are estimated for each year from expected project balances as of December 31st of the preceding year.
O Payment of taxes will normally be at the end of January of the year following the tax year. (e.g. 1984-to taxes are based on project expenditures through December 31. 1983 and will be paid at the end of January 1985.) (2) Estimated taxes represent the combined amounts applicable to Houston Lighting & Power Company's 30.8Z ownership interest an$ Central Power & Light Comapny's 25.21 ownership interest. The ressining 44% of the South Texas Project is owned by tax exempt entities. (3) The above estimates assume continuation of 1983 tax rates throughout the 1984-89 period (except for Palacios Seava11 Commission, which was created during 1984, and will levy taxes at a statutory 10d per $100 tax rate). The South Texas Project's Isrge annual additions to the listed jurisdictions' tax base would normally be expected to offer the opportunity for tax rate reductions. While the listed estimates may be overstated to the extent of future tax rate reductions, the amounts and timing of such rate reductions if any, are not presently determinable. (4) The estimates assume continuation of the valuation methodology currently being used. (5) Dollar Value is in the year stated. (6) 1988 is the first full year of operation of Unit 11 1990 is the first full year of operation of Unit 2. Source: ER-OL, page 8.1-11.
1 f l Table 5.3 (Sumuary Table S-3) Uranium-fuel-cycle environmental datat (Normakzed to model LWR annual fuel requrement (WASH-1248] or reference reactor year [NUREG-01161). [See footnotes at end of this table) Erwronmental consderatons Total "*""*#*C'P*"""*U**9""'**"'0' I reference reactor year of modet 1.000 MWe LWR NATURAL RESOUACE USE Land (acres): Temporanly cc:rmtted 8 100 Urdstuced area 79 Desurbed area 22 Equrvaient to a 110 MWe coakfred power plant. Permanentty committed 13 Ovarburden moved (mnons of MT) 2.8 EqurvaHmt to 95 MWe coal-fred power plant Water (meons of gallons): Oscharged to at 160 =2 percent of modet 1.000 MWe LWR with cooleng D$ charged to water bodies .. ...l 11.090 Dscharged to ground. . . . . , 127 Total .- . . . . . 11.377 <4 percent of modet 1.000 MWe LWR with once-through coohng Fossd fuel. Electncal energy (thousands of MW-%s).. 323 < 5 percent of model 1.000 MWe LWR output. Equrvaient coal (thousands of MT) 118 Equrvaient to the consumpton of a 45 MWe coal-fred power plant. Natural gas (tmflsons of scf) 135 <04 percent of modet 1.000 MWe energy output. EFFLUENTS-CHEMCAL (MT) Gases (nclueng entrasnment).
- SO. 4,400 NO.* 1.190 Equrvaient to emasons from 45 MWe coaLfred piant for a year.
Hydrocarbons 14 CO-- 29 6 Partculates 1,154 Other gases-F .. 67 Pnncipally from UF. production, enrichrnent, and reprocessing. Concentration within range of state standards-below level that has effects on human health. hcl .014 Loads: S0 . . 9.9 From enrchment, fuel fabncaton and reprocesesng NO . .. 25.8 steps. Components that constitute a potentaal for Fluonde 12.9 adversa ermronmental effect are present an deute Ca" 5.4 concentratons and recorve sdos anal douton by re-C1- 8.5 connng bodies of water to levels below permosable Na* 12.1 standards. The constituents that rope douton and NH. 10.0 the flow of driuton water are: NH.-600 cis., NO.- Fe .4 20 cis.. Fluoride-70 cis. . Taslings solutens (thousands of MT). 240 From melts only-no segnrfcant effluents to ermronment. Solids 91.000 Pnnesparty from rails-no segrufcont effluents to erm-ronment l Source: 10 CFR 51.51 (1-1-85 Edftion), p. 533. l l South Texas DES 5-40
Table 5.3 (Continued) Ermronmental consideratons M*""""" '"'C' P annual fuel reaurement or Total reference reactor year of model 1,000 MW, LWa Effluents-Radiological (cunes) Gsses (includmg entramment) Rn-222 Presency under reconsadoraten by the Commiseen. Ra-226 .02 Th-230 .02 Urarwum .034 Tntium (thousands) 18.1 C-14 .. 24 Kr-85 (thousands) 400 Ru-106 .14 Pnncipally from fuel reprocessang plants. 1-129. 1.3 1-131. .83 Tc-99 Presentry under consaderston by the Commissaon Fission products and transurarwes .203 Lx3unds Uraruum and daughters 2.1 Pnncspelly from rndhng--encAuded tadings hquor and re-tumed to ground-mo effluents therefore, no effect on envronment. Ra-226 .0034 From UF. production. Th-230 .0015 Th-234 .01 From fusi febnceton plants-concentraton 10 percent of 10 CFR 20 *or total procesemg 2f annual fuel regarements for enodel LWR. Frssaon and actrvaten products 5.9 x 10-* Sohds (buned on ade). Other than high level (shanow) 11,300 9,100 Ci comes from low level reactor wastes and 1,500 Cs comes from reactor decontaminaten and decommesesoning--buned at land bunal facdrbes 600 Ce comes from truits-encluded en tadegs retumed to ground Approrsmate*y 60 Ce comes from cis.eason and spent fuel storage. No sagrwficant emuent to the ermronment. TRU and HLW (doep) " 1,1 x 10 Buned at Federal Repos# tory. Effluents-thermal (bdhons of Babsh thermal unrts) 4,063 <5 percent of model 1,000 MWe LWR. Transportaton (persorwom): Exposure of workers and general -p 2.5 Occupatonal exposure (persorwom) 22.6 From reproceseng and weste management. 8 in some comes where no entry appears it is cieer from sie background documents that the metter was addreteed and that, in effect the Table should be reed as if a specinc mero had boon made. However, there are other areas that are not addressed at all in the Table. Table S-3 does not include aflects from the effluents desenbad n the Table, or eenmates of roleeses of Radon-222 from the wenlum fuel cycss or seemeses of Technetum-99 reteneed from weste management or reprocesemg actmeos. These issues may be tio e@fect of ki the inev6 dual . of the Urarnum Fuel ." W 1248 April 1974; the - Data this table are even in the "Ermronmental "Ermronmental of the Reprocesemg and Waste Management Porton of the LWR uel Cycle," NUREG-0116 (Swp.1 to WASH-1248); the "Pubhc Comments and Task Force Roeponses Regardog the Ermronmentaf Survey of the Reprocemeng and Waste Management Portons of the LWR Fuel Cycle," NUREG-0216 (Supp. 2 to WASH-1248), and en the record of the final rulemalung pertaining to Uraneum Fuel Cycle impacts from Spent Fuel Reprocesseng and Radioactive Weste Management. Docket RM-50-3. The contnbutons from reprocess.ng waste ma ment and transportaten of wastes are mammzed for either of the two fuel cycles (uransum only and no recycle). The con on from transportation excludes transportation of cold fuel to a reactor and of irradiated fuel and redcactive wastes from a reactor which are conssdered e Table S-4 of f 51.20(g) The contnbutsons from the other s' ops of the fuel cycle are grven in columns A-E of Table S-3A of WASH-1248
- The contreutions to temporanty commrtted land from reproceeemg are not prorated over 30 years, since the compie*
temporary empact accrues regardless of whether the plant services one reactor for one year or 57 reactors for 30 yee 8 Estrnated emuents based won combuston of equrvalent cosi for power generston.
- 1.2 percent from natural gas use and process.
South Texas DES 5-41
Table 5.4 (Summary Table S-4) Environmental impact of transportation of fuel and waste to and from one light-water-cooled nuclear power reactor! Normal Conditons of Transport Envronmental anpact Heat (per wre&sted fusi cask in transet 250,000 Stu/hr. Wesght rgoverned by Federal or State restnctons) 73,000 be. per truck; 100 tons por cask por rait car. Traffic donesty-Truck Lees then 1 por day. Rail Lees than 3 per month Esa rnated Cumuistvo does number of Range of doses to eW to expoesti r W populabon persons induduals * (per reactor year) popuiston (per exposed reactor yeer)
- Transportation workers.. 200 0.01 to 300 trwilrem.. 4 man rem General pubic Onlookers . 1,100 0.003 to 1.3 trwierem. 3 man-rem Along Route 600,000 0 0001 to 0.06 rmilwom .
Accdemts en Transport Envronmental nsk Radelogscal effects. Small
- Corrw (nonradiologecal) causes.. 1 fatal injury m 100 reactor years,1 nonfatal efury en 10 reactor years; $475 property damage per reactor year.
8 Data supportog ttws table are geven m the Commason's Envronmental Survey of Transportaten of Radioactive Matena s to and from Nuclear Power Plants
- WASH-1238, December 1972 and Supp.1 NUREG-75/038 Apnl 1975 Both documents are avadable for enspectson and copyng at the Commesson's Pubhc Document Room,1717 H St. NW., Wastwngton. D C. and may be obtamed from Natonal Techrwcal information Sennce Spnngfield Va. 22161. WASH-1238 es avadable from NTIS at a cost of $5 45 (mecrofiche, $2 25) and NUREG-75/038 es avadable at a cost of 53.25 (rrwcrofiche. $2.25).
8 The Federal Radiaton Couned has recommended that the radiaton doses from all sources of radation other than natural background and rnedical exposures should be hmited to 5,000 rmferem per year for mdmduals as a resurt of occupatoral exposure and should be imted to 500 truthrem per year for edeviduals en the gene el populaton. The dose to endmduals due tv average natural background radiaton is about 130 melinem per year.
- Man-rem es an expresson for the summaton of whole body doses to andrvduals en a group. Thus, sf each member of a population group of 1,000 people were to receive a dose M 0.001 rem (1 mdirem), or if 2 people were to receeve a dose of 0.5 rem (500 trulinem) each. the total man-rem dose en each .sse would be 1 man-rem.
- Athough the envronmental nsk of radological effects ste'mmmg from transportaten accdents es currently mcapable of bong nur.sencally quantified, the nsk remains smatt regardless of whether it rs bemg appded to a smgie reactor or a multreactor site.
Source: 10 CFR 5.52 (1/1/85 edition), p. 534. South Texas DES 5-42
Table 5.5 Incidence of job-related mortalities-Mortality rates, premature Occupational group deaths per 105 person years Underground metal miners * *1300 Uranium miners
- 420 Smelter workers
- 190 Mining ** 61 Agriculture, forestry, and fisheries ** 35 Contract construction ** 33 Transportation and public utilities ** 24 Nuclear plan't worker *** 23 Manufacturing ** 7 Wholesale and retail trade ** 6 Finance, insurance, and real estate ** 3
~ Services ** 3 Total private sector ** 10
*U.S. Department of Health,' Education, and Welfare, May 1972. **U.S.~ Bureau of Labor Statistics. ***The nuclear-plant workers' risk is equal to the sum of the radiation-related risk and the nonradiation-related risk. The estimated occupational risk associated with the industrywide average radiation dose of 0.8 rem is about 11 potential premature deaths per 105 person years.from cancer, based on the risk estimators described in the following text. The average non-radiation-related risk for seven U.S. electrical utilities over the period 1970-1979 is about 12 actual premature deaths per 105 person years as shown in Figure 5 of the paper by Wilson and Koehl (1980). (Note that the esti-mate of 11 radiation-related premature cancer deaths describes a potential risk rather than an observed statistic.)
i 1 i South Texas DES 5-43
Table 5.6 Preoperational radiological environmental conitoring program 0
~
"o c
g gp y COLLECIloN ANALYSIS
-4 .
NOMINAL COLLECI- MINIMUM g AND/OR SAMPLE MEDIA NOMINAL NUMBER OF SAMPLE .RoUIINE SAMPLING-g IDCATIONS HODE TIoM FREQUENCY ANALYSIS n'PE ANALYSIS FRF1)UENCY - ca
$ 1. Direct Radiation Total Stations: 40 Continuous Quarterly Camma Quarterly TLD's 16 stations located in six-teens sectors approximately 1 mile or less from contain-ment.
16 stations located in six-teen sectors 4-6 miles from containment. 6 stations located in spe-cial interest areas (e.g. school, population center) within a 14 mile radius of w containment. l f 2 control stations located A in areas of minimal wind l I direction (W,ENE) 10-15 i miles from containment.
- 2. Airborne Total Station: 18 Continuous Weekly Radiodine
- a. Radiofodine (8), Canister:
Particulates 3 stations located at the 1-131 Weekly exclusion zone, approxi- Particulate mately 1 alle from con- Sample: tainment, in the N,NNW,NW Cross Beta Weekly sectors. Camma-Isotopic Quarterly composite 4 stations located in (by location)' special interest areas, 4-14 miles from contain-ment. I control station located in a minimal wind direc-tion (W) 11 miles from containment. Source: ER-OL Table 6.1-16, Amendment 7, 12/21/84.
. - - . - . _ _ . _ .~ . . - - _ ._ _ _ _ . . _ - _ - -
i C Table 5.6 (Continued) g- EXPOSURE PATHWAY COLLECTION ANALYSIS x
'$ AND/OR SAMPLE MEDIA NOMINAL NUMBER OF SAMPLE ROUTINE SAMPLING NOMINAL COLLECT- MINDGt i tJ 14 CATIONS MODE TION FREQUENCY ANALYSIS TYPE AltALYSIS FREQUENCY m
i M i b. Soils (10) Grab Semiennually- Casma-Isotopic According. to collec-8 same as air stations. tion frequency , r 2 stations located on or adjacent to fatus within 5 miles of containment.
- 3. Waterborne Total Stations: 17
- a. Surface @ Monthly Comma-Isotopic Monthly
- 1 station located in re- Composite servoir at point of reser- Tritium Quarterly composite m voir blowdown to Colorado A
! River.
- 1 control station located above the Site on the Colorado River not in -
fluenced by plant discharge. 1 station approximately 2 miles downstream from blow-down entrance into the Colorado River (marker). Relief Ws11 discharse exit
.monitorina 1 station located near Site Crab quarterly (if Cross Beta, Quarterly or accord-boundary in the Little available) Tritium ing to collection ;
I Robbins Slough. frequency . I station located near Site boundary in the East Fork of Little Robbins Slough. I station located near Site boundary in the West Branch of the Colorado River. . I i
E Table 5.6 (Continued) 5r p . p COLLECTION- ANALYSIS M
$ AND/OR SAMPLE MEDIA NOMINAL NUMBER OF SAMPLE ROtfIINE SAMPLING NOMINAL COLLECT- MINIMUh c 1ACATIONS MODE TION FREQUENCY ANALYSIS TYPE ANALYSTS FREQUENCY
- b. Cround M 1 station located at well Crab Quarterly (if c==g-Isotopic , Quarterly or
#6038 upgradient from the available) Tritium according to col-reservoir in the upper lection frequency shallow aquifer.
I station located at well M46A down gradient in the upper shallow aquifer. I station located at well
#603A upgradient from the m reservoir in the lower S ahallow aquifer.
'l station located at well
#446 down gradient in the -
lower aquifer.
- c. Drinking M 1 station located on Site. Crab Monthly Casma-Isotopic Monthly Tritium
- d. Sediment M i station located near Site Crab Semiannually (if casusa-Isotopic According to the boundary in the Little available) collection frequency Robbins Sicugh.
I station located near Site boundary in the West Branch of the Celorado River. 1 control station located above the Site on the Colorado River not influ-enced by plant discharge. l
__ _. _ . _ _ _ . .. . . _m _ . . . . _ _ _ _ . . _ _ . . .. _. m O . c Table 5.6 (Continued) a c+ t 3' l -4
- @ QM.LECTION ANALYSIS
- m EXPOSURE PATifWAY e AND/OR SAMPLE MEDIA NOMINAL NUDSER OF SAMPLK RotTEINE SAMPLING NOMINAL COLLECT- MINIMUM Q I4 CATIONS MODE TION PREQUENCY ANALYSIS TYPE ANALYSIS FREQUENCY i
4 4
- d. Sediment 1 station located approxi-(Cont'd) sately 2 miles downstreae from blowdown entrance into
, the Colorado River. 1 station located in reser-voir at point of reservoir 4 blowdown to Colorado River. ,
- 1 station located in reser-voir near coolant discharge.
o, i
- 4. Ingestion Total Stations: 10 4 f N ---------------------------
- a. Milk Limited source of sample in vicinity at STPECS----------------------------------
(Attempts will be ande to collect samples when available) / Crab Semimonthly when Csama-Isotopic & According to collec-' l on pasture, monthly low I4 vel 1-131 tion frequency ] at other tisse i d en available. i
- b. Broadleaf M (Standardized 3 stations located at the Crab Monthly during Comma-Isotopic Monthly
! plant types) exclusion zone, approxi- growing season ; ! mately 1 mile from contain- (when available) . ment, in the N,NW,NNW sec-l tors. 1 control station located i in a minimal wind direction (W), 11 miles from ,; containment. i i u i I
'E E.
- r Table 5.6 (Cont.inued)
-4 p y COLLECTION ANALYSIS e AND/OR SAMPLE BEDIA NCBf!NAL IRBtBER OF SAMPLE ' ROUTINE SAMLING IICetINAL COLLECT- MINDEBt
{ p IDCATIONS MODE TION FREQUENCY ANALYSIS TYPE. _ ANALYSIS F=.uv a i
- c. Agricultural --------------------------- No sample stations have been identified in the vicinity----------------------------
- Projects of the Site. Presently no agricultural land is irrigated by water into which liquid plant wastes will be discharged.
l Agricultural products will be considered if these conditions change. i
- d. Terrestrial M
& Aquatic 1 sample representing Grab Sample in seasons Gamma-Isotopic According to collec-Animals commercially and/or or semiannually (Edible portion) tion frequency
) , recreationally impor- if they are not l g tant species in vicin- seasonal.' l CD ity of STPEGS that may be influenced by plant operation. . (e.g. fish, same birds).
*1 sample of same or analogous species in area not influenced by STPEGS.
I sample of same or anala-gous species in the reser-voir (if available).
- e. Pasture Grass (2) 1 station location at the Grab Quarterly (when cat- Gamme-Isotopic. According to collec-exclusion zone, NW. tie are on pasture) tion frequency I control station 11 miles W.
- Applies to aquatic saeples only.
1
(- _ E Table 5.6 (Continued) g '
- r
-4 ANAt.YSIS COLLECTION k- EXPOSURE PATWAY
'a AND/OR SAMPLE tetDIA NOMINAL NUMBER OF SAMPLE ROUTINE SAMPLING IIONINAL COLLECT- HINIltRf ANALYSIS TYPE ANALYSYS FREQUENCY g LOCATTONS _HODE T10ll FREQUENCY
- f. Domestic Heat (1)
(Edible 1 saeple representitg Scalannually Casuma-Isotopic . According to collec-
~
portion) domestic stock fed on crops. tion frequency exclusively grown uithin 10 miles of contairment. T 8 i
6 EVALUATION OF THE PROPOSED ACTION 6.1 Unavoidable Adverse Impacts-The staff has reassessed the physical, social, biological, and economic impacts that can be attributed to the operation of STP 1&2. These impacts are summar-ized in Table 6.1. The FES-CP required several modifications to the aquatic biological monitoring program at STP 1&2 for the purpose of impact assessment. These modifications have been made and the results of the studies conducted at both facilities are evaluated in Sections 4.3.4 and 5.5.2 of this report. The radiological impacts from the operation of STP 1&2 have been re-evaluated and are discussed in Section 5.9 of this report. The application is required to adhere to the following conditions for the pro-tection of the environment: (1) Before engaging in any additional. construction or operational activities that may result in any significant adverse environmental impact that was not evaluated or that is significantly greater than that evaluated in this statement, the applicant will provide written notification of such activi-ties to the Director of the Office of Nuclear Reactor Regulation and will receive written approval from that office before proceeding with such activities. (2) The applicant will carry out the environmental monitoring programs outlined in Section 5 of this statement, as modified and approved by the staff and implemented in the Environmental Protection Plan and Technical Specifica-tions that will be. incorporated in the operating licenses. (3) If an' adverse environmental effect or evidence of irreversible environmental damage is detected during the operating life of the plant, the applicant will provide the staff with an analysis of the problem and a proposed course of action to alleviate it. 6.2 Irreversible and Irretrievable Commitments of Resources
-There have been no significant changes in the staff's evaluation for STP 1&2 since the construction permit stage environmental review. l 6.3 Relationship Between Short-Term Use and Long-Term Productivity There have been no significant changes in the staff's evaluation for STP 1&2 since the construction permit stage environmental review.
6.4 Benefit-Cost Summary Table 6.1 provides a summary of benefits and costs for STP 1&2.
' South Texas DES 6-1
6.4.1 Benefits A major benefit to be derived from the operation of South Texas Project Units 1 and 2 is the lower production cost for approximately 12.0 billion kWh of base-load electrical energy that will be produced annually. This projection assumes that each unit will operate at an annual average capacity factor of 55%. (Assum-
~
1 ing a higher capacity factor would, of course, result in greater benefit due to avoidance of higher production costs for replacement power.) The addition of the units will also improve the applicants' ability to supply system load re-quirements by contributing 2480 MW of capacity to the bulk power supply system in the State of Texas.
~
The staff estimates that production costs avoided on existing fossil-fueled ! generating units will be approximately 48.2 mills per kWh on 12.0 billion kWh, resulting in a total avoided cost per year on existing generating facilities of $578 million (1984 dollars). 6.4.2 Economic Costs The economic costs associated with station operation include fuel costs and 1 operation and maintenance costs (0&M), which are expected to average approxi-matelys7.3 mills per kWh and 12.7 mills per kWh, respectively. Total annual production costs for the 12.0 billion kWh per year produced by the facility n would be $240 million (1984 dollars). The estimates for fuel and O&M costs are from NUREG/CR-4012, " Replacement Energy Costs for Nuclear Electricity-Generating
; Units in the United States", October 1984.
The cost of decommissioning the South Texas Project is anticipated to range
.from $37 to $60 million per unit (1984 dollars). This estimate is derived from
~
NUREG-0586, " Draft Generic Environmental Impact Statement on Decommissioning j Nuclear Facilities." This cost represents the 10% annual escalation of the 1978 dollar value costs of the alternative decommissioning methods presented in the report. 6.4.3 Socioeconomic Costs i. No significant socioeconomic costs are expected from either the operation of STP 1&2 or from the number of station personnel and their families living in the area. The socioeconomic impacts of a severe accident could be large; howev~er, the probability of such an accident.is small. I 6.5 Conclusion As a result of its analysis and review ~ of potential environmental, technical, and social. impacts, the NRC staff has prepared an updated forecast of the effects of operation of STP 1&2. The NRC staff has determined that STP 1&2 can be operated with minimal environmental impact. To date, no new information has been obtained that alters the overall favorable balancing of the benefits of station operation versus the environmental costs that resulted from evalua-l tions made at the construction permit stage. l l South Texas DES 6-2
6.6 References U.S. Nuclear Regulatory Commission, NUREG-0586, " Draft Generic Environmental Impac+ Statement on Decommissioning Nuclear Facilities," January 1981.
-- , NUREG/CR-4012, " Replacement Energy Costs for Nuclear Electricity-Generating Units in the United States," October 1984.
South Texas DES 6-3
Table 6.1 Benefit-cost summary for South Texas Project, Units 1 and 2 Primary impact and effect on population or resources Quantity /(section)* Impact ** BENEFITS Capacity Additional generating capacity 2,480 MWe Large Economic Reduction in existing system 12 billion kWh/yr Large production costs @48.2 mills /kWh or
$578 million/yr*** Moderate COSTS Economic Fuel 7.3 mills /kWh*** Small Operation and maintenance 12.7 mills /kWh*** Moderate TOTAL $240 million/yr Moderate Decommissioning $37-60 million*** Small Environmental Damages suffered by other water tsers Surface water consumption (Sec. 5.3.1) Small Surface water contamination (Sec. 5.3.2) Small Ground water consumption (Sec. 5.3.1.2) Small Ground water contamination (Sec. 5.3.2) None Damage to aquatic resources Impingement and entrainment (Sec. 5.5.2) Small Thermal effects (Sec. 5.3.2 and 5.5.2) Small Chemical discharges (Sec. 5.3.2) Small Damage to terrestrial resources Cooling tower operation (Sec. a.5.1.2) Small Transmission line maintenance (Sec. E.5.1.3) Small Adverse socioeconomic impacts Loss of historic or archeological resources (Sec. 5.7) None Increased demand on public facilities and services (Sec. 5.8) Small Increased demands on private facilities and services (Sec. 5.8) Small Noise (Sec. 5.12) None Adverse nonradiological health effects Water quality changes (Sec. 5.3.2.1) None Air quality changes (Sec. 5.4.1 and 5.4.2) None *See footnotes at end of table South Texas DES 6-4
Table 6.1 (Continued) Primary impact and effect on population or resources Quantity (section)* Impact ** COSTS (Continued) Adverse radiological health effects Routine operation (Sec. 5.9.3) Small Postulated accidents (Sec. 5.9.4) **** Uranium fuel cycle (Sec. 5.10) Small
*Where a particular unit of measure for a benefit / cost category has not been specified in this statement or where an estimate of the magnitude of the benefit / cost under consideration has not been made, the reader is directed to the appropriate section of this report for further information.
** Subjective measure of cost and benefits is assinned by reviewer where quantification is not possible: "Small" = impacts that in the reviewer's judgment are of such minor nature, based on currently available informa-tion, that they do not warrant detailed investigation or consideration of mitigative actions; " Moderate" = impacts that in the reviewer's judgment are likely to be clearly evident (mitigation alternatives are usually considered for moderate impacts); "Large" = impacts that in the reviewer's judgment represent either a severe penalty or a major benefit. # ceptance requires that large negative impacts be more than offset by other over-riding project considerations.
***1987 dollars. The net reduced generating cost is the difference bet-een
$203 million/ year and $140 million/ year or $63 million/ year. This.is the savings figure provided in Section 6.4.2 of the DES. ,
**** Impacts of an accident could possibly be large while the risk of an acc.ient is small.
South Texas DES 6-5
7 CONTRIBUTORS
~The following personnel of the Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission, participated in the preparation of this document:
A. Brauner Site Analyst; B.S. (Electrical Engineering), 1950, 35 years' experience. l L. Bykoski Regional Environmental Economist; Ph.D. (Economics), 1965; 20 years' experience K. Dempsey Nuclear Engineer; 8.S. (Nuclear Engineering), 1973; 12 years' experience.
.J. Fairobent Meteorologist; M.S. (Meteorology), 1972; 13 years' experience.
R. Fell Nuclear Engineer; Ph.D. (Mechanical Engineering), 1978; 19 years' experience. R. Gonzales Hydraulic Engineer; B.S. (Civil Engineering), 1965; 20 years' experience. C. Hickey Senior Fishery Biologist; M.S. (Marine Science),1971; 14 years' experience. N. P. Kadambi- Licensing Project Manager; Ph.D. (Nuclear Engineering), 1971; 15 years' experience. G. LaRoche Senior Land Use Analyst; Ph.D. (Botany-Ecology), 1969; 16 years' experience. I. Lee Licensing Assistant; B.A. (Business), 1964; 13 years' experience. E. Pentecost Physical Scientist; Ph.D. (Ecology), 1972; 13 years' experience. J. Swift Health Physicist; Ph.D. (Nuclear Engineering), 1971; 19 years' experience. M. Wangler Health Physicist; M.S. (Physics), 1972; 13 years' experience. R. Wescott Hydraulic Engineer; M.S. (Engineering Science), 1974; 11 years' experience. J. Wilson Project Manager; M.S. (Zoology), 1973; 12 years'
~
. experience.
South Texas DES 7-1 l
The following contractor personnel from~0ak Ridge National Laboratory partici-pated in the preparation of this document: V. Tolbert Aquatic Ecologist; Ph.D. (Ecology), 1978; 7 years' , experience. J. Webb Terrestrial Ecologist,;-Ph.D. (Insect Ecology), 1975; 10 years' experience. South Texas DES 7-2
8 AGENCIES, ORGANIZATIONS, AND INDIVIDUALS TO WHOM COPIES OF THIS ENVIRONMENTAL STATEMENT ARE BEING SENT Advisory Council on Historic Preservation Federal Emergency Management Agency Federal Energy Regulatory. Commission Oak Ridge National Laboratory State of Texas Attorney General State of Texas Clearinghouse
' State of Texas Bureau of Radiation Control State of Texas Office of the Governor U.S.- Army Corps of Engineers U.S. Department of Agriculture U.S. Department of Commerce U.S. Department of Energy U.S. Department of Health and Human' Services
,. U.S. Department of Housing and Urban Development U.S. Department of Interior U.S. Department of Transportation U.S. Environmental Protection Agency I, South Texas DES' 8-1 4 1 _ _ _ , _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _-_ .- w . . -- -
+ -.
9 RESERVED FOR STAFF RESPONSE TO COMMENTS ON THE DRAFT ENVIRONMENTAL STATEMENT l South Texas DES 9-1
APPENDIX A RESERVED FOR COMMENTS ON THE DRAFT ENVIRONMENTAL STATEMENT i South Texas DES Appendix A
APPENDIX B l NEPA POPULATION-DOSE ASSESSMENT l l Population-dose commitments are calculated for all individuals living within 80 km (50 miles) of the South Texas facility, employing the same dose calcula-tion models used for individual doses (see RG 1.109, Revision 1), for the pur-pose of meeting the "as low as reasonably achievable" (ALARA) requirements of 10 CFR 50, Appendix I. In addition, dose commitments to the population resid-ing beyond the 80-km region, associated with the export of food crops produced within the 80-km region ard with the atmospheric and hydrospheric transport of the more mobile effluent species (such as noble gases, tritium, and carbon-14) are taken into consideration for the purpose of meeting the requirements of the National Environmental Policy Act, 1969 (NEPA). This-appendix describes the methods used to make these NEPA population-dose estimates. (1) Iodines and Particulates Released to the Atmosphere Effluent nuclides in this category deposit onto the ground as the effluent moves downwind; thus the concentration of these nuclides remaining in the plume
.is continuously being reduced. Within 80 km of the facility, the deposition model in RG 1.111, Revision 1, is used in conjunction with the dose models in RG 1.109, Revision 1. Site-specific data concerning production and consumption of foods within 80 km of the reactor are used. For estimates of population doses beyond 80 km, it is assumed that excess food not consumed within the 80-km area would be consumed by the population beyond 80 km. It is further assumed that none, or very few, of the particulates released from the facility will be transported beyond the 80-km distance; thus, they will make no significant contribution to the population dose outside the 80-km region, except by export of food crops.
(2) Noble Gases, Carbon-14, and Tritium Released to the Atmosphere For locations within 80 km of the reactor facility, exposures to these effluents are calculated with a constant mean wind-direction model according to the guid-ance provided in RG 1.111, Revision 1, and the dose models described in RG 1.109, Revision 1. For estimating the dose commitment from these radionuclides to the population of the United States residing beyond the 80-km region, two dispersion regimes are considered. These are referred to as the first pass-dispersion regime and the worldwide-dispersion regime. The model for the first pass-dispersion regime estimates the dose commitment to the population from the radioactive plume as it leaves the facility and drifts across the continental United States toward the northeastern corner of'the United States. The model for the worldwide-dispersion regime estimates the dose commitment to the popu-lation of the United States after the released radionuclides mix uniformly in the.world's atmosphere or oceans. t South Texas DES 1 Appendix B
l (a) First-Pass Dispersion For estimating the dose commitment to the population of the United States resid-ing beyond the 80-km region as a result of the first pass of radioactive pol-lutants, it is assumed that the pollutants disperse in the lateral and vertical directions along the plume path. The direction of movement of the plume is assumed to be from the facility toward the northeast corner of the United States. The extent of vertical dispersion is assumed to be limited by the ground plane and the stable atmospheric layer aloft, the height of which determines the mix-ing depth. The shape of such a plume geometry can be visualized as a right cylindrical wedge whose height is equal to the mixing depth. Under the assump-tion of constant population density, the population dose associated with such a plume geometry is independent of the extent of lateral dispersion, and is only dependent upon the mixing depth and other nongeometrical related factors (NUREG-0597). The mixing depth is estimated to be 1000 m (0.6 mile), and a uniform population density of 62 persons /km2 is assumed along the plume path, with an average plume-transport velocity of 2 m/sec (7 ft/sec). The total-body population-dose commitment from the first pass of radioactive effluents is due principally to external exposure from gamma-emitting noble gases, and to internal exposure from inhalation of air containing tritium and from ingestion of food containing carbon-14 and tritium. (b) Worldwide Dispersion For estimating the dose commitment to the U.S. population after the first pass, worldwide dispersion is assumed. Nondepositing radionuclides with half-lives greater than 1 year are considered. Noble gases and carbon-14 a are assumed to mix uniformly in the world's atmosphere (3.8 x 1018 m ), and radioactive decay is taken into consideration. The worldwide-dispersion model estimates the activity of each nuclide at the end of a 20 year release period (midpoint of reactor life) and estimates the annual population-dose commitment at that time, taking into consideration radioactive decay and physical removal mechanisins (for example, carbon-14 is gradually removed to the world's oceans). The total-body population-dose commitment from the noble gases is due mainly to external exposure from gamma-emitting nuclides, whereas from carbon-14 it is due m' inly to' internal exposure from ingestion of food containing carbon-14. The population-dose commitment as a result of tritium releases is estimated in a manner similar to that for carbon-14, except that after the first pass, all the tritium is assemed to be immediately distributed in the world's circulating water volume (2.7 x 1016 m3 ) including the top 75 m of the seas and oceans, as well as the rivers and atmospheric moisture. The concentration of tritium in the world's circulating water is estimated at the time after 20 years of re-leases have occurred, taking into consideration radioactive decay; the popula-tion-dose commitment estimates are based on the incremental concentration at that time. The total-body population-dose commitment from tritium is due mainly to internal exposure from the consumption of food. (3) Liquid Effluents Population-dose commitments due to effluents in the receiving water within 80 km of the facility are calculated as described in RG 1.109, Revision 1. It is assumed that no depletion by sedimentation of the nuclides present in the 2 Appendix B South Texas DES
l. l receiving water occurs within 80 km.' It also is assumed that aquatic biota concentrate radioactivity in the same manner as was assumed for the ALARA evalu-ation for the maximally exposed individual. However, food-consumption values appropriate for the average, rather than the maximally exposed, individual are used. It is further assumed that all the sport and commercial fish and shell-fish caught within the 80-km area are eaten by the pop'ulation of the United
< States.-
Beyond 80 km, it is assumed that.all the liquid-effluent nuclides except tri- l tium have deposited on the sediments so that they make no further contribution to population exposures. The tritium is assumed to mix uniformly in the world's circulating water volume and to result in an exposure to the population of the United States in the same manner as discussed for tritium in gaseous effluents.
~
(4) References
-U.S. Nuclear Regulatory Commission, NUREG-0597, K. F..Eckerman et al., " User's Guide to GASPAR Code," June 1980.
-- , RG 1.109, " Calculation of Annual Doses to Man from Routine Releases of Reactor Effluents for the Purpose of Evaluating Compliance with 10 CFR Part 50, Appendix I," Revision 1, October 1977.
-- , RG 1.111, " Met' hods for Estimating A'tmospheric Transport and Dispersion of Gaseous Effluents in Routine Releases f. rom Light-Water-Reactors," Revision 1, July 1977.
South Texas DES .3 Appendix B
1 l 1 l l APPENDIX C IMPACTS OF THE URANIUM FUEL CYCLE The following assessment of the environmental impacts of the light-water reactor (LWR)-supporting fuel cycle
- as related to the operation of the proposed project is based on the values given in Table S-3 of Title 10 of the Code of Federal Regulations, Part 51 (10 CFR 51)'(see Table 5.3 in the main body of this report) and the staff's estimates of radon-222 and technetium-99 releases. For the sake of consistency, the analysis of fuel-cycle impacts has been cast in terms of a model 1000-MWe LWR operating at an annual capacity factor of 80%. In the fol-lowing review and evaluation of the environmental impacts of the LWR-supporting fuel cycle, the staft's analysis and conclusions would not be appreciably al-tered if the analysis were to be based on the net electrical power output of each of the two units of the South Texas plant.
(1) Land Use The total annual land requirement for the fuel cycle supporting a model 1000-MWe LWR is about 460,000 m 2 (113 acres). Approximately 53,000 m2 (13 acres) per l year are permanently committed land, and 405,000 m (100 acres) per year are 2 temporarily committed. (A " temporary" land commitment is a commitment for the life of the specific fuel-cycle plant, such as a mill, enrichment plant, or i succeeding plants. On abandonment or decommissioning, such land can be used for any purpose. " Permanent" commitments represent land that may not be re-leased for use after plant shutdown and/or decommissioning.) Of the 405,000 m 2 per year of temporarily committed land, 320,000 m2are undisturbed and 90,000 m2 are disturbed. Considering common classes of land use in the United States,** fuel-cycle land-use requirements to support the model 1000-MWe LWR do not repre-sent a significant impact. (2) Water Use The principal water-use requirement for the fuel cycle supporting a model 1000-MWe LWR is that required to remove waste heat from the power stations sup-plying electrical energy to the enrichment step of this cycle. Of the total annual requirement of 43 x 106 m3 (11.4 x 109 gal), about 42 x 106 m3 are required for this purpose, assuming that these plants use once-through cooling. Other water uses involve the discharge to air (for example, evaporation losses
*The LWR-supp ing fuel cycle consists of all fuel cycle steps other than reac-tor operatior. . follows: mining and milling of uranium, uranium hexafluoride conversion, isotopic enrichment, uranium oxide fuel fabrication, fuel reprocess-ing and transportation, irradiated-fuel storage, and waste management. **A coal-fired plant of 1000-MWe capacity using strip-mined coal requires the disturbance of about 810,000 m 2 (200 acres) per year for fuel alone.
South Texas DES 1 Appendix C l
in process cooling) of about 0.6 x 106 m3 (16 x 107 gal) per year and water discharged to the ground (for example, mine drainaga) of about 0.5 x 106 m 3 per year. On a thermal effluent basis, annual discharges from the nuclear fuel cycle are about 4% of those from the model 1000-MWe LWR using once-through cooling. The consumptive water use of 0.6 x 106 m 3 per year is about 2% of that from the model 1000-MWe LWR using cooling towers.' The maximum consumptive water use (assuming that all plants supplying electrical energy to the nuclear fuel cycle used cooling towers) would be about 6% of the model 1000-MWe LWR using cooling towers. Under'this condition, thermal effluents would be negligible. The staff finds that these combinations of thermal loadings and water consumption are acceptable relative to the water use and thermal discharges of the proposed project. (3) Fossil Fuel Consumption Electrical energy and process heat are required during various phases of the fuel-cycle process. The electrical energy is usually produced by the combus-tion of fossil fuel at conventional power plants. Electrical energy associated with the fuel cycle represents about 5% of the annual elec.trical power produc-tion of the model 1000-MWe LWR. Process heat is primarily generated by the combustion of natural gas. This gas consumption, if used to' generate electric-ity, would be less than 0.3% of the electrical output from the model plant. The staff finds that the direct and indirect consumptions of electrical energy for fuel-cycle operations are small and acceptable relative to the net power production of the proposed project. (4) Chemical Effluents The quantities of chemical, gaseous, and particulate effluents associated with fuel-cycle processes are given in Table S-3 (Table 5.3, this report). The principal species are sulfur oxides, nitrogen oxides, and particulates. On the basis of data in a Council on Environnental Quality report (CEQ, 1976), the staff finds that these emissions constitute an extremely small additional atmos-pheric loading in comparison with the same emissions from the stationary fuel-combustion and transportation sectors in the United States; that is, about 0.02% of the annual national releases for each of these species. The staff believes that such'small increases in releases of these pollutants are acceptable. Liquid chemical effluents produced in fuel cycle processes are related to fuel-enrichment, -fabrication, and -reprocessing operations and may be released to receiving waters. These effluents are usually present in dilute concentrations so that only small amounts of dilution water are required to reach levels of concentration that are within established standards. The flow of dilution water required for specific constituents is specified in Table S-3. Additionally, all liquid discharges into the navigable waters of the United States from plants associated with the fuel-cycle operations will be subject to requirements and' limitations set forth in the National Pollutant Discharge Elimination System (NPDES) permits for these plants. 2, Tailings solutions and solids are generated during the milling process. These solutions and solids are not released in quantities sufficient to have a sig-nificant impact on the environment. i South Texas DES 2 Appendix C
F (5) Radioactive Effluents
~
Radioactive effluents estimated to be released to the environment from re-processing and wasta-management activities and certain other phases of the fuel-cycle process are set forth in Table S-3 (Table 5.3). Using these data, the staff has calculated for 1 year of operation of the model 1000-MWe LWR the 100 year environmental dose commitment
- to the population of the United States from the LWR-supporting fuel cycle. Dose commitments are provided in this sec-tion for exposure to four categories of radioactive releasesi (1) airborne effluents that are quantified in Table S-3 (that is, all -radionuclides except radon-222 and technetium-99); (2) liquid effluents that are quantified in Table S-3 (that is, all radionuclides except technetium-99); (3) the staff's estimates of radon-222 releases; and (4) the staff's estimate of technetium-99 releases. Dose commitments from the first two categories are also described in
- a proposed explanatory narrative for Table S-3, which was published in the Federal Register on March 4, 1981 (46 FR 15154-15175).
(a) Airborne Effluents
; Population dose estimates for exposure to airborne effluents are based on the annual releases listed in Table S-3, using an environmental dose commitment (EDC) time of 100 years.* The computational code used for these estimates is the RABGAD code originally developed for use in the " Generic Environmental Impact Statement on the Use of Mixed 0xide Fuel in. Light-Water-Cooled Nuclear Power Plants" (GESM0) (NUREG-0002, Chapter IV, Section J, Appendix A). Two
, generic sites are postulated for the points of release of the airborne efflu-ents: (1) a site in the midwestern United States for releases from a fuel reprocessing plant and other facilities, and (2) a ' site in the western United States for releases from milling and a geological repository. The following environmental pathways were considered in estimating doses: (1) inhalation and submersion in the plume during its initial passage; (2) in-gestion of food; (3) external exposure from radionuclides deposited on soil; and (4) atmospheric resuspension of radionuclides deposited on soil. Radio-nuclides released to the atmosphere from the midwestern site are assumed to be transported with a mean wind speed of 2 m/sec over a 2413-km (1500-mile)** path-way from the midwestern United States to the northeast corner of the United States, and deposited on vegetation (deposition velocity of 1.0 cm/sec) with subsequent uptake by milk- and meat producing animals. No removal mechanisms are assumed during the first 100 years, except normal weathering from crops to i soil (weathering half-life of 13 days). Doses from exposure to carbon-14 were
- estimated using the GESMO model to estimate ~ the dose to the population of the United States from the initial passage of carbon-14 before it mixed in the j world's carbon pool. The model developed by Killough (1977) was used to esti-i mate doses from exposure to carbon-14 after it mixed in the world's carbon pool.
*The 100 year environmental dose commitment is the integrated population dose for 100 years; that is, it represents the sum of the' annual population doses for a total of 100 years.
**Here and elsewhere in this narrative, insignificant digits are retained for purposes of internal consistency in the model.
- South Texas DES 3 Appendix C
In a similar manner, radionuclides released from the western site were assumed to be transported over a 3218-km (2000-mile) pathway to the northeast corner of the United States. The agricultural characteristics that were used in com-puting doses from exposure to airborne effluents from the two generic sites are described in GESMO (NUREG-0002, page.IV J(A)-19). To allow for an increase in population, the population densities used in this analysis were'50% greater than the values used in GESMO (NUREG-0002, page IV J(A)-19). (b) Liquid Effluents Population dose estimates for exposure to liquid effluents are based on the annual releases listed in Table S-3 and the hydrological model described in GESMO (NUREG-0002, pages IV J(A)-20, -21, and -22). The following environ-
. mental pathways were considered in estimating doses: (1) ingestion of water and fish; (2) ingestion of food (vegetation, miik, and beef) that had been produced through irrigation; and (3) exposure from shoreline, swimming, and boating activities.
It is estimated from these calculations that the overall total-body-dose com-mitment to the population of the United States from exposure to gaseous re-leases from the fuel cycle (excluding reactor releases and the dose commitment due to radon-222 and technetium-99) would be approximately 450 person-rem to the total body for each year of operation of the model 1000-MWe LWR (reference reactor year, or RRY). Based on Table S-3 values, the additional total-body dose commitments to the population of the United States from radioactive liquid effluents (excb d.ng i technetium-99) as a result of all fuel-cycle operations other than reactor operation would be about 100 person rem per year of opera-tion. Thus, the estimated 100 year environmental dose commitment to the popu- , lation of the United States from radioactive gaseous and liquid releases due to these portions of the fuel cycle is about 550 person-rems to the total body
/whole body) per RRY.
Because there are higher dose commitments to certain organs (for example, lung, bone, and thyroid) than to the total body, the total risk of radiogenic cancer is not addressed by the total-body-dose commitment alone. Using risk estimators of 135, 6.9, 22, and 13.4 cancer deaths per million person-rem for total-body, bone, lung, and thyroid exposures, respectively, it is possible to estimate the total-body risk-equivalent dose for certain organs (NUREG-0002, Chapter IV, Section J, Appendix B). The sum of the total-body risk-equivalent dose from those organs was estimated to be about 100 person-rem. When this value is added to the value of 550 person-rem shown in the previous paragraph, the total 100 year environmental- dose commitment would be about 650 person-rem (total-body risk-equivalent dose) per RRY. (Section 5.9.3.1(1) of this report de-scribes the health effects modela in more detail.) (c) Radon-222 At this time the quantities of radon-222 and technetium-99 releases are not listed in Table-S-3. Principal radon releases occur during mining and milling operations and as emissions from mill tailings, whereas principal technetium-99 i releases occur from gaseous diffusion enrichment facilities. The staff has , determined that radon-222 releases per RRY from these operations are as given in Table C.1. The staff has calct: lated population-dose commitments for these South Texas DES 4 Appendix C l l
I l sources of radon-222 using the RABGAD computer code described in Volume 3 of NUREG-0002 (Chapter IV, Section J, Appendix A). The results of these calcula-tions for mining and milling activities prior to tailings stabilization are listed in Table C.2. The staff has considered the health effects associated with the releases of radon-222, including both the short-term effects of mining and milling and active tailings, and the potential long-term effects from. unreclaimed open pit
' mines and stabilized tailings. The staff has assumed that after completion of active mining, underground mines will be sealed, returning releases of radon-222 to background levels. For purposes of providing an upper bound impact assess-ment, the staff has assumed that open pit mines will be unreclaimed and has calculated that if all ore were produced from open pit mines, releases from them would be 110 Ci per RRY. However, because the distribution of uranium-ore reserves available by conventional mining methods is 66% underground and 34% -open pit (U.S. Department of Energy, 1978), the staff has further assumed that uranium to fuel LWRs will be produced by conventional mining methods in these proportions. This means that long-term releases from unreclaimed open pit mines will be 0.34 x 110 or 37 Ci per year per RRY.
Based on a value of 37 Ci per year per RRY for long-term releases from unre-claimed open pit mines, the radon released from unreclaimed open pit mines over 100- and 1000 year periods would be about 3700 Ci and 37,000 Ci per RRY, respec-tively. . The environmental dose commitments for a 100- to 1000 year period would be as shown in Table C.3. These commitments represent a worst-case situation in that no mitigating circum-stances are assumed. However, State and Federal laws currently require reclama-tion of strip and open pit coal mines, and it is very probable that similar reclamation will be required for open pit uranium mines. If so, long-term re-leases from such mines should approach background levels. For long-term radon releases from stabilized tailings piles, the staff t.as assumed that these tailings would emit, per RRY,1 Ci per year for 100 years, 10 Ci per year for the next 400 years, and 100 Ci per year for periods beyond 500. years. With these assumptions, the cumulative radon-222 release from stabilized-tailings piles per RRY would be 100 Ci in 100 years, 4090 Ci in 500 years, and 53,800 Ci in 1000 years (Gotchy, 1978). The total-body, bone, and bronchial epithelium dose commitments for these periods are as shown in Table C.4. Using risk estimators of 135, 6.9, and 22 cancer deaths per million person-rems for total-body, bone, and lung exposures, respectively, the estimated risk of cancer mortality resulting from mining, milling, and active-tailings emissions of radon-222 (Table C.2) is about 0.11 cancer fatality per RRY. When the risks from radon-222 emissions from stabilized tailings and from reclaimed and un-reclaimed open pit mines are added to the value of 0.11 cancer fatality, the overall risks of radon-induced cancer fatalities per RRY are as follows: 0.19 fatality for a 100 year period 2.0 fatalities for a 1000 year period South Texas DES 5 Appendix C
l These doses and predicted health effects have been compared with those that can l be expected from natural-background emissions of radon-222. Using data from j the National Council on Radiation Protection (NCRP, 1975), the staff calculates the average radon-222 concentration in air in the contiguous United States to be about 150 pCi/m a , which the NCRP estimates will result in an annual dose to the bronchial epithelium of 450 millirem. For a stabilized future United States population of 300 million, this represents a total lung-dose commitment of 135 million person-rem per year. Using the same risk estimator of 22 lung-cancer fatalities per million person-lung-rem used to predict cancer fatalities for the model 1000-MWe LWR, the staff estimates that lung-cancer fatalities alone from background radon-222 in the air can be calculated to be about 3000 per year, or 300,000 to 3,000,000 lung-cancer deaths over periods of 100 to 1000 years, respectively. Current NRC regulations (10 CFR 40, Appendix A) require that an earth cover not less than 3 meters (10 feet) in depth be placed over tailings to reduce the radon-222 emanation from the disposed tailings to less than 2 pCi/m2-sec, on a calculated basis above background. In October 1983, the U.S. Environmental Protection Agency (EPA) published environmental standards for the disposal of uranium and thorium mill tailings at licensed commercial processing sites (EPA, 1983). The EPA regulations (40 CFR 192) require that disposal be designed to limit radon-222 emanation to less than 20 pCi/m2-sec, averaged over the surface of the disposed tailings. The staff is reviewing its regulations for tailings disposal to ensure that they conform with the EPA regulations. Although a few of the dose estimates in this appendix would change if NRC adopts EPA's higher radon-222 flux limit for disposal of tailings, the basic conclusion of this appendix should still be valid. That conclusion is: "The staff concludes that both the dose commitments and health effects of the LWR-supporting uranium fuel cycle are very small when compared with dose commitments and potential health effects to the U.S. population resulting from all natural-background sources." (d) Technetium-99 The staff has calculated the potential 100 year environmental dose commitment to the population of the United States from the release of technetium-99. These calculations are based on the gaseous and the hydrological pathway model systems described in Volume 3 of NUREG-0002 (Chapter IV, Section J, Appendix A) I and are described in more detail in the staff's testimony at the OL hearing for the Susquehanna Station (Branagan and Struckmeyer, 1981). The gastrointestinal i tract and the kidney are the body organs that receive the highest doses from exposure to technetium-99. The total body dose is estimated at less than 1 person-rem per RRY, and the total-body risk-equivalent dose is estimated at less than 10 person-rem per RRY. l (e) Summary of Impacts The potential radiological impacts of.the supporting fuel cycle are summarized in Table C.5 for an environmental dose commitment time of 100 years. For an environmental dose commitment time of 100 years, the total-body dose to the population of the United States is about 790 person-rem per RRY, and the cor-responding total-body risk-equivalent dose is about 2000 person-rem per RRY. In a similar manner, the total-body dose to the population of the United States South Texas DES 6 Appendix C
r l i is about 3000 person rem per RRY, and the corresponding total-body risk-equiva'. mt dose is about 15,000 person-rem per RRY using a 1000 year environ-mental dsse commitment time. Multiplying the total-body risk-equivalent dose of 2000 person-rem per RRY by the preceding risk estimator of 135 potential cancer deaths per million person-rem, the staff estimates that about 0.27 cancer death per RRY may occur in the population of the United States as a result of exposure to effluents from the fuel cycle. Multiplying the total-body dose of 790 person-rem per RRY by the genetic risk estimator of 258 potential cases of all forms of genetic disorders per million person-rem, the staff estimates that about 0.20 potential genetic disorder per RRY may occur in all future generations of the population exposed during the 100 year environmental dose commitment time. In a similar manner, the staff estimates that about 2 potential cancer deaths per RRY and about 0.8 potential genetic disorder per RRY may occur using a 1000 year environmental dose commitment time. Some perspective can be ga.ned by comparing the preceding estimates with those from naturally occurring terrestrial and cosmic-ray sources. These average about 100 millirem. Therefore, for a stable future population of 300 million persons, the whole-body dose commitment would be about 30 million person-rem per year, or.3 billion person-rem and 30 billion person-rem for periods of 100 and 1000 years, respectively. These natural-background dose commitments could produce about 400,000 and 4,000,000 cancer deaths and about 770,000.and 7,700,000 genetic disorders, during the same time periods. From the above analysis, the staff concludes that both the dose commitments and health effects of the LWR-supporting uranium fuel cycle are very small when compared with dose commitments and potential health effects to the U.S. population resulting from all natural-background sources. (6) Radioactive Wastes The quantities of buried radioactive waste material (low-level', high-level, and transuranic wastes) associated with the uranium fuel cycle are specified in Table S-3 (Table 5.3). For low-level waste disposal at land-burial facilities, the Commission notes in Table S-3 that there will be no significant radioactive releases to the environment. The Commission notes that high-level and trans-uranic wastes are to be buried at a Federal repository and that no release to the environment is associated with such disposal. NUREG-0116, which provides back-ground and context for the high-level and transuranic waste values in Table S-3 established by the Commission, indicates that these high-level and transuranic wastes will be buried and will not be released to the biosphere. No radiologi-cal environmental impact is anticipated from such disposal. (7) Occupational Dose The annual occupational dose attributable to all phases of the fuel cycle for the model 1000-MWe LWR is about 200 person-rem. The staff concludes that this occupational dose will have a small environmental impact. (8) Transportation The transportation dose to workers and the public is specified in Table S-3 (Table 5.3). This dose is small in comparison with the natural-background dose.
. South Texas DES 7 Appendix C
1 l . (9) Fuel Cycle The staff's analysis of the uranium fuel cycle did not depend on the selected fuel cycle (no recycle or uranium-only recycle), because the data provided in Table S-3 (Table.5.3) include maximum recycle-option' impacts for each element of j the fuel cycle. Thus the staff's conclusions as to acceptability of the envi-ronmental impacts of the fuel cycle are not'affected by the specific fuel cycle selected. (10) References Branagan, E. ,-and R. Struckmeyer, testimony from "In the Matter of Pennsylvania Power & Light Company, Allegheny Electric Cooperatives, Inc. (Susquehanna Steam Electric Station, Units 1 and 2)," NRC Docket Nos. 50-387 and 50-388, presented on October 14, 1981, in the transcript following p. 1894. Council on Environmental Quality, "The Seventh Annual Report of the Council on Environmental Quality," Figures 11-27 and 11-28, pp. 238-239, September 1976. Gotchy, R. , testimony from "In the Matter of Duke Power Company (Perkins Nuclear Station)," NRC Docket No. 50-488, filed April 17, 1978. s Killough, G.-G.,."A Diffusion-Type Model of the Global Carbon Cycle for the
-Estimation of Dose to the World Population from Releases of Carbon-14 to the Atmosphere," Oak Ridge National Laboratory ORNL-5269, May 1977.
- National Council on Radiation Protection and Measurements (NCRP), " Natural Back-ground Radiation in the United States," NCRP Report _45, November 1975.
U.S. Department of Energy, " Statistical Data of the Uranium Industry," GJ0-100(8-78), January 1978. U.S. Environmental Protection Agency, " Environmental Standards for Uranium and Thorium Mill Tailings at Licensed Commercial Processing Sites (40 CFR 192)," Federal Register, Vol. 48, No. 196, pp. 45926-45947, October 7, 1983.
- U.S. Nuclear Regulatory Commission, NUREG-0002, " Final Generic Environmental Statement on the Use of Recycled Plutonium-in Mixed 0xide Fuel in Light-Water-Cooled Reactors," August 1976.
-- , NUREG-0116, " Environmental Survey of the Reprocessing and Waste Management Portions-of the LWR Fuel Cycle" (Supplement 1 to WASH-1248), October 1976.
l l [ i South Texas DES 8 Appendix C
Table C.1 Radon releases from mining and milling operations and mill tailings for each year of operation of the model 1000-MWe LWR
- Radon source Quantity released Mining ** 4060 Ci Milling and tailings *** (during active mining) 780 Ci Inactive tailings *** (before stabilization) 350 Ci Stabilized tailings *** (several hundred years)- 1 to 10 Ci/ year Stabilized tailings ***~(after several hundred years) 110 Ci/ year
*After 3 days of hearings before the Atomic Safety and Licensing Appeal Board (ASLAB) using the Perkins record in a " lead case" approach, the ASLAB issued a decision on Maj 13, 1981.(ALAB-640) on the radon-222 release source term for the uranium fuel cycle. The decision, among other matters, produced new source term numbers based on the record developed at the hearings. These new numbers did not differ significantly from those in the Perkins record, which are the values set forth in this table. In ALAB-701, the Appeal Board af-firmed the Perkins Licensing' Board's approval of comparing radon re-lease rates to natural radon releases in arriving at a de minimus con-clusion. The Commission,'in CLI-83-14, decided to hold 7eview of ALAB-701 in abeyance. Because the source term numbers in ALAB-640 do not differ significantly from those in the Perkins record, the staff continues to conclude that both the dose commitments and health effects of the uranium fuel cycle are insignificant when compared to dose commitments and potential health effects to the U.S. population resulting from all natural background sources. **R. Wilde, NRC transcript of direct testimony given "In the Matter of Duke Power Company (Perkins Nuclear Station)," Docket No. 50-488, April 17, 1978. ***P. Magno, NRC transcript of direct testimony given "In the Matter of
- Duke Power. Company (Perkins Nuclear Station)," Docket No. 50-488, April 17, 1978.
South Texas DES 9 Appendix C
Table C.2 Estimated 100 year environmental dose commitment per year of operr. tion of the model 1000-MWe LWR Environmental dose commitments i Total-body Lung risk-Total (bronchial equivalent body Bone epithelium) dose Radon-222 (person- (person- (person- (person-Radon source releases (Ci) rem) rem) rem) rem) Mining 4100 110 2800 2300 630 Milling and active tailings 1100 29 750 620 170 Total 5200 140 3600 2900 800 Table C.3 Estimated 100 year environmental dose commitments from unreclaimed open pit mines for each year of operation of the model 1000-MWe LWR Environmental dose commitments Total-body Lung risk-Total- (bronchial equivalent body Bone epithelium) dose Time span Radon-222 (person- (person- (person- (person-(years) releases (Ci) rem) rem) rem) rem) 100 3,700 96 2,500 2,000 550 500 19,000 480 13,000 11,000 2000 1000 37,000 960 25,000 20,000 5500 i I l South Texas DES 10 Appendix C l
Table C.4 Estimated 100 year environmental dose commitments from stabilized-tailings piles for each year of operation of the model 1000-MWe LWR Environmental dose commitments Total-body Lung risk-Total- (bronchial equivalent body Bone epithelium) dose Time span Radon-222 (person- (person- (person- (person-(year) releases (Ci) rem) rem) rem) rem) 100 100 2.6 68 56 15 500 4,090 110 2,800 2,300 630 1000 53,800 1400 37,000 30,000 8200 Table C.5 Summary of 100 year environmental dose commitments per year of operation of the model 1000-MWe light-water reactor Total-body risk-Total-body equivalent Source (person-rem) (person-rem) All nuclides in Table S-3 (Table 5.3) except radon-222 and technetium-99 550 650 Radon-222 Mining, milling, and active tailings, 5200 Ci 140 800 Unreclaimed open pit mines, 3700 Ci 96 550 Stabilized tailings, 100 Ci 3 15 Technetium-99, 1.3 Ci* <1 <10 Total 790 2000
- Dose commitments are based on the " prompt" release of 1.3 Ci/RRY. Additional releases of technetium-99 are estimated to occur at a rate of 0.0039 Ci/yr/RRY af ter 2000 years of placing wastes in a high-level-waste repository.
South Texas DES 11 Appendix C
APPENDIX D
-EXAMPLES OF3GESPECIFIC DOSE ASSESSMENT CALCULATIONS (1) Calculational Approach As mentioned in the main body of this report, the quantities of radioactive material that may be released annually from the South Texas facility are esti-mated on the basis of the description of the design and operation of the rad-waste systems as contained in the applicant's FSAR and by using the calculative models and parameters described in NUREG-0017. These estimated effluent release values for normal operation, including anticipated operational occur-rences, along with the applicant's site and environmental data in the ER-OL and in subsequent answers to NRC staff questions, are used in the calculation of radiation doses and dose commitments.
The models and considerations for environmental pathways that lead to estimates of radiation doses and dose commitments tc individual members of the public near the plant and of cumulative doses and dose commitments to the entire pop-uiation within an 80-km (50-mile) radius of the plant as a result of plant operations are discussed in detail in RG 1.109, Revision 1. Use of these models with additional assumptions for environmental pathways that lead to exposure to the general population outside the 80-km radius is described in Appendix B of this statement. The calculations performed by the staff for the releases to the atmosphere and hydrosphere provide total integrated dose commitments to the entire population within 80 km of this facility based on the projected population distribution in the year 2010. The dcse commitments represent the total dose that would be received over a 50 year period, following the intake of radioactivity for 1 year'under the conditions existing 20 years after the station begins operation (that is, the midpoint of station operation). For younger persons, changes in organ mass and metabolic parameters with age after the initial intake o' radioactivity are accounted for. (2) Dose Commitments from Radioactive Effluent Releases , The staff estimates of the expected gaseous and particulate releases (listed in Table D.1) and the site meteorological consideritions (summarized in Table D.2) were used to estimate radiation doses and dose commitments for airborne efflu-ents. Individual receptor locations and pathway locations considered for the maximally exposed individual in these calculations are listed in Table D.3. Annual average relative concentration (x/Q) values and relative deposition (D/Q) values at specified points of interest and arrays of the X/Q and 0/Q valves by direction out to distances of 50 miles from the plant were calculated. Ali releases were considered as ground level, with adjustments for mixing within the building cavity. A straight-line trajectory atmospheric dispersion model, 1 Appendix D South Texas DES
1 1 described in RG 1.111, " Methods for Estimating Atmospheric Transport and Dis- I persion of Gaseous Effluents in Routine Releases from Light-Water-Cooled Reactors," was used; however, because of the location of the South Texas Project site near the Gulf of-Mexico and the occasional development of a sea-breeze circulation pattern extending as far inland as the site, X/Q and D/Q values were adjusted for consideration of spatial and temporal variations in airflow using the correction factors contained in NUREG/CR-2919. In addition to the continuous release, one 400-hour purge release was assumed in accordance with the recommendation of the staff. The purge release was evaluated using the methodology described in NUREG/CR-2199. Four years (January 1974 through December 1977) of onsite meteorological data, provided by the applicant on magnetic tape, were used for this evaluation. Wind speed and direction were based on measurements made at the 10-m (33-ft) level, and atmospheric stability was defined by the vertical temperature gradient measured between the 60-m (195-ft) and 10-m levels. Site boundary distances were taken from Table 6.2-22 of the applicant's Environmental Report (Amend-ment 8), and locations of the nearest receptors were taken from Attachment 2 of ST-HL-AE-1327, Environmental Report Dose Analysis Information. The applicant used a slightly different meteorological data base, July 21, 1973 through September 30, 1977 with the exclusion of data for the period July 21, 1976 through September 30, 1976. The applicant also did not consider any adjustments to the straight-line model for spatial and temporal variations of airflow. Consequently, the applicant's X/Q values are generally lower than the staff's values, ranging from factors of around 4 at the nearest receptors / boundaries to around 1.1 at the furthest receptors / boundaries. The staff estimates of the expected liquid releases (listed in Table D.4), along with the site hydrological considerations (summarized in Table D.5), were used to estimate radiation doses and dose commitments from liquid releases. (a) Radiation Dose Commitments to Individual Members of the Public As explained in the text, calculations are made for a hypothetical individual member of the public (that is, the maximally exposed individual) who would be expected to receive the highest radiation dose from all pathways that contri-bute. This method tends to overestimate the doses because assumptions are made that would be difficult for a real individual to fulfill. The estimated dose commitments to the individual who is subject to maximum exposure at selected offsite locations from airborne releases of radioiodine and particulates, and waterborne releases are listed in Tables D.6, D.7, and 0.8. The maximum annual total body and skin dose to a hypothetical individual and the maximum beta and gamma air dose at the site boundary are presented in Tables D.6, D.7, and D.8. The maximally exposed individual is assumed to consume well above average quantities of the potentially affected foods and to spend more time at poten-tially affected locations than the average person as indicated in Tables E-4 and E-5 of Revision 1 of RG 1.109. South Texas DES 2 Appendix D I
(b) Cumulative Dose Commitments to the General Population Annual radiation dose commitments from airborne and waterborne radioactive I releases from the South Texas-facility are estimated for two populations in the l year 2010: (1) all members of the general public withir. 80 km (50 miles) of the station (Table D.7) and (2) the entire U.S. population (Table D.9). Dose commitments beyond 80 km are based on the assumptions discussed in Appendix B of this report. For perspective, annual background radiation doses are given in the tables for both populations. (3) References U.S. Nuclear Regulatory Commission, NUREG-0017, " Calculation of Releases of Radioactive Materials in Gaseous and Liquid Effluents From Pressurized Water-Reactors (PWR-GALE Code)," April 1976.
-- , NUREG/CR-2919, "X0QD0Q Computer Program for the Meteorological Evaluation of Routine Effluent Releases at Nuclear Power Stations," Pacific Northwest Laboratory, September 1982. -- , RG 1.109, " Cal'culation of Annual Doses to Man From Routine Releases of Reactor Effluents for the Purpose of Evaluating Compliance with 10 CFR Part'50, t Appendix I," Revision 1, October 1977.
l -- , RG 1.111, " Methods for Estimating Atmospheric Transport and Dispersion of l Gaseous Effluents in Routine Releases From Light-Water Reactors," Revision 1, 1977. 1 i l South Texas DES 3 Appendix D
Table D.1 Calculated releases of radioactive materials in' gaseous effluents from South Texas Project, Units 1 and 2 (Ci/yr/ reactor) Reactor building Auxiliary, fuel handling Nuclide purge and turbine buildings
- Total Kr-85m 120 3.0 123 Kr-85 41 909 950 Kr-87 47 4 51 Kr-88 160 9 169 Xe-131m 230 99 329 Xe-133m 57 0 57 Xe-133 1300 23 1323 Xe-135m 10 4 14 Xe-135 850 22 872 Xe-138 8 4 12 Total 3900 Cr-51 0.0091 0.00032 0.0094 Mn-54 0.0052 0.00008 0.0053 Co-57 0.0008 0. 0 0.0008
-Co-58 0.025 0.0021 0.027 Co-60 0.0026 0.00059 0.0032 Fe-59 0.0027 0.00005 0.0028 Sr-89 0.013 0.00077 0.014 Sr-90 0.0051 0.0003 0.0054 Zr-95 0.0 0.001 0.001 Nb-95 0.0018 0.00005 0.0019 Ru-103 0.0016 0.00002 0.0016 Cs-134 0.0025 0.00055 0.0031 Cs-136 0.0032 0.00005 0.0033 Cs-137 0.0054 0.00075 0.0062 Ba-140 0. 0 ~ 0.0004 0.0004 Ce-141 0.0013 0.00003 0.0013 I-131 0.034 0.12 0.154 I-133 0.094 0.40 0.494 Total -- --
0.74 H-3 0.0 150 150 C-14 7. 3 0. 0 7. 3 Ar-41 34 0.0 34
*All releases considered cont 1:iucus.
South Texas DES 4 Appendix 0
i Table D.2 Summary.of atmospheric dispersion factors (X/Q) and relative deposition values for maximum site boundary and receptor locations near' South Texas Project, Units 1 and 2 Relative Location
- Source ** 3 deposition /m 2 X/Q (sec/m )
Nearest effluent ' A 5.5 x 10 8 4.2 x 10 8 control boundary B 3.7 x 10 8 2.8 x 10 8 (1.6 km NNW) Nearest residence A 1.3 x 10 8 8.2 x 10 9 (3.2 km N) B 6.9 x 10 7 4.4 x 10 9 Nearest garden A 4.9 x 10 7 2.0 x 10 8 (6.4 km NW) B 2.3 x 10 7 9.2 x 10 10 . Nearest milk cow. A 3.2 x 10 8 8.5 x 10 10 (7.7 km WNW) B 1.1 x 10 7 2.9 x 10 10 Nearest milk _ goat' A 1.3 x 10 7 2.2 x 10 10 (8.7 km ENE) B 2.7 x 10 8 4.1 x 10 11 Nearest meat animal A 6.6 x 10 G 5.1 x 10 8 (1.5 km NNW) B 4.5 x 10 8 3.5 x 10 8
*" Nearest" refers to that type of location where the highest radiation dose is expected to occur from all appropriate pathways. ** Sources:
A - Reactor-building vent, purge. B - Turbine-building-ventilation exhaust, and auxiliary and fuel handling building exhausts, continuous release. i South Texas DES 5 Appendix D
Table D.3 Nearest pathway locations used for maximally exposed individual dose commitments for' South Texas Project, Units 1 and 2 Location Sector Distance (km)* Nearest effluent- NNW 1.6 control boundary ** Residence *** N 3.2 ~ Garden NW 6.4 Milk cow WNW 7.7 Milk goat ENE 8.7 Meat animal NNW 1. 5
*To convert km to miles multiply by 0.6214. ** Beta and gamma air doses, total body doses, and skin doses from noble gases are determined at the effluent-control boundaries in the sector where the maximum potential value is likely to occur. *** Dose pathways, including inhalation of atmospheric radioactivity, exposure to deposited radionuclides, and submersion in gaseous radioactivity, are evaluated at residences.
6 Appendix 0 South Texas DES
1 Table D.4 Calculated release of radioactive materials in liquid effluents from South Texas Project, Units 1 and 2 Nuclide Ci/yr/ reactor Nuclide Ci/yr/ reactor Corrosion and activation prodacts Fission products (continued) Na-24 0.0019 Te-129m 0.00004
- - P-32 0.00018 Te-129 0.00003
- Cr-51 0.0053 Te-131m 0.00012 Mn-54 0.0042 Te-131 0.00002 Fe-55 0.0075 I-131 0.17 Fe-59 0.0023 -Te-132 0.00024 Co-58 0.0089 I-132 0.0052 Co-60 0.014 .I-133 0.17 Ni-63 0.0017 Cs-134 0.026 Zn-65 0.00011 I-134 0.00061 Zr-95 -0.0012 I-135 0.058 Nb-95 0.002 Cs-136 0.002 W-187 0.00017 Cs-137 0.036
.Np-239 0.00027 Ba-137m
~
0.019 Ba-140 0.0035 Fission products La-140 0.0040 Ce-141 0.00026 Sr-89 0.00012 Ce-143 0.00025 Sr-90 0.00002 Pr-143 0.00004 Sr-91 0.00002 Ce-144 0.0048 Y-91m 0.00001 Pr-144 0.00086 Y-91 0.00009 Y-93 0.0001 Total 0.56 Mo-99 0.00091 (except tritium) Tc-99m 0.00081 Ru-103m 0.0016 Tritium release 1360 Ru-103 0.0019 Ru-106 0.029' Rh-106 0.02 Ag-110m 0.0015
.Ag-110 0.00004 LSb-124 0.00043 1.
4 N i South Texas DES 7 Appendix D
Table D.5 Summary of hydrologic transport and dispersion for liquid releases from South Texas Project, Units 1 and 2* Transit time Dilution Location (hours) factor Nearest drinking-water intake ** -- -- Nearest sport-fishing location 0.1 22 (discharge arca)*** Nearest shoreline 0.1 22 (bank of Colorado River near discharge area) Nearest beach on Gulf 1.0 220
*See RG 1.113, " Estimating Aquatic Dispersion of Effluents.From Accidental and Routine Reactor Releases for the Purpose of Implementing Appendix 1," April 1977.
**No known use of Colorado River water for drinking water, downstream of plant discharge.
*** Assumed for purposes of an upper limit estimate.
i l South Texa's DES 8 Appendix 0
Table D.6 Annual dose commitments to a maximally exposed individual near the South Texas Project, Units 1 and 2
~ Doses of (mrem /yr/ unit, except as noted):
Noble gases in gaseous effluents Total Gamma air dose Beta air dose i Location Pathway body Skin (mrad /yr/ unit) (mrad /yr/ unit) \ N2arest* site Direct radiation 0.6 1.4 0.9 1.1 bsundary(1.6 km NNW) from plume ' Iodine and particulates in gaseous effluents ** l Total body Organ
-Nzarest*** site Ground deposition 0.2 0.3- (skin) boundary (1.6 km NNW) Inhalation a- 0.6 (C) (thyroid)
Nzarest residence Ground deposition a 0.1 (skin) (3.2 km WNW)- Inhalation a 0.1 (C) (thyroid) Nsarest milk cow Cow milk consumption a 0.8 (I) (thyroid) O.4 (C) (thyroid) (7.7 km WNW) N2arest milk goat Goat milk consumption a 0.2 (I) (thyroid) 0.1 (C) (thyroid) (8.7 km ENE)
' Nearest garden Vegetable consumption 0.1 (C) 0.1 (C) (thyroid) l~ (6.4 km NW) 0.5 (C) (bone)
' Nearest meat animal Meat consumption a 0.4 (C) (thyroid) (1.5 km NNW) 0.2 (C) (bone) Liquid effluents **
' Total body Organ Drinking water. Water ingestion l . Nearest fish at Fish consumption 0.6 (A) 0.9 (A T)(liver) plant discharge area 0.9 (C) (bone) a a Nearest shore access Shoreline recreation near plant discharge area Note: a = Less than 0.1 mrem / year.
'*" Nearest" refers to that site boundary location where the highest radiation doses l
as a result of gaseous effluents have been estimated to occur.
*" Doses are for the age group and organ that results in the highest cumulative dose l for the location: A= adult, T= teen, C= child, != infant. Calculations were made for l 'those age groups and these organs: gastrointestinal tract, bone, liver, kidney, thyroid lung, and skin.
***" Nearest" refers to the location where the highest radiation dose to an individual from all applicable pathways has been estimated.
****No existing drinking water pathway identified.
South Texas DES 9 Appendix 0
._ ___ .- - . _ _ - . , ,_ ~
Table D.7 Calculated Appendix I (10 CFR 50) dose commitments to a maximally exposed individual and to the population from operation of South Texas Project, Units 1 and 2 Annual dose per reactor unit
- Individual Appendix I Calculated Source design objectives
- doses **
^ Liquid effluents Dose to total body from all pathways 3 mrem 0.6 mrem Dose to any organ from all pathways 10 mrem 0.9 mrem (A-liver & C-bone) Noble gas effluents (at site boundary) Gamma dose in air 10 mrad 0.9 mrad 1 Beta dose in air 20 mrad 1.~1 mrad Dose to total body of an individual 5 mrem 0.6 mrem Dose to skin of an individual 15 mrem 1.4 mrem Radiofodines and~particulates*** Dose to any organ from all air pathways 15 mrem 1.0 mremt ., (thyroid) Population dose within 80 km, person rem Total body Thyroid Natural-background radiationtt 26,000 i Liquid effluents 0.6 0.2 Noble gas effluents 0.1 0.1 Radioiodine and particulates 0.2 1
- Design Objectives from Sections II.A, II.8, II.C, and II.D of Appendix I, 10 CFR 50 consider doses to maximally exposed individual and to population per reactor unit.
** Numerical values in this column were obtained by summing appropriate values in Table 0.6. Locations resulting in maximum doses are represented here.
*** Carbon-14 and tritium have been added to this category.
.tAssumes a child at the nearest residence consuming vegetables from the nearest garden, milk from the nearest cow, and meat from the nearest meat animal.
ft" Natural Radiation Exposure in the United States," U.S. Environmental Protection Agency, ORP-SID-72-1, June 1972; using the average outdoor background dose for the Corpus Christi, ~ Texas, area of 82 mrem /yr, and year 2010 projected population of 320,000. South Texas DES 10 Appendix D i - _ . _- - - -_ - --- - - - - , .-..
~
Table D.8 Calculated RM-50-2 dose commitments to a maximally exposed i individual from operation of South Texas Project, Units 1 and 2* Annual dose per site RM-50-2 design Calculated Source objectives ** doses Liquid effluents Dose to total body or any organ from l all pathways 5 mrem 2 mrem Activity-release estimate, excluding
' tritium 10 Ci 1.1 Ci Noble gas effluents (at site boundary)
Gamma dose in air 10~ mrad 2 mrad Beta dose in air 20 mrad 2 mrad Dose to total body of an individual 5 mrem 1 mrem Dose to skin of an individual 15 mrem 3 mrem
~
Radioiodines and particulates*** Dose to any organ from all air pathways 15 mrem 1 mrem (thyroid) 1-131 activity release 2 Ci 0.3 Ci
*An optional method of demonstrating compliance with the cost-benefit section (II.0) of Appendix I to 10 CFR 50. ** Annex to Appendix I to 10 CFR 50.
- Carbon-14 and tritium have been added to this category.
1 I South Texas DES 11- Appendix 0
Table D.9 Annual total-body population dose commitments, year 2010 (both units) U.S. population dose commitment, Category person-rem /yr Natural background radiation
- 28,000,000*
South Texas 1 and 2 (combined) operation Plant workers 1,020 General public Liquid effluents ** 3.3 Gaseous effluents 73 Transportation of fuel and waste .6
*Using the average U.S. background dose (100 mrem /yr) and year 2010 projected U.S. population from " Population Estimates and Projections," Series II, U.S. Department of Commerce, Bureau of the Census, Series P-25, No. 704, July 1977.
**80-km (50-mile) population dose South Texas DES 12 Appendix D
APPENDIX E NPDES PERMIT i 1 South Texas DES Appendix E
O% UNITED STATES ENVIRONMENTAL f*ROTECTION AGENCY REGION V8 j 1801 ELM STREET DALLAS. TEXAS 75370 OCT 1S E33 CERTIFIED MAIL: RETURN RECEIPT REQUESTED (P 012 035 184) Mr. W. F. McGui re Manager, Environmental Protection Department Houston Lighting and Power Company P.O. Box 1700 Houston, Texas 77001 Re: Application to Discharge to Waters of the United States Pemit No. TX0064947
Dear Mr. McGuire:
Enclosed is the public notice of the Agency's final permit decision and a copy of our response to coments and the final pemit. This puDlic notice describes any sub,stantial changes from the draft pem.it. If you intend to request an evidentiary hearing , please follow the requirements outlined in the public notice of the draft permit. Should you have any questions please feel free to contact the Pemits Branch at the above address or telephone (214) 767-4375. Sincerely, M y m h f.-re Myron 0. Knudson, P.E. Director, Water Management Division (6W) Enclosures cc w/pemit copy: Texas Department of Water Resources r South Texas DES 1 Appendix E
_. . ~ _ _ ._ _ - _ - - - _ _ _ - . , _ _ _ - - - - - _ _ - Advertising Order Number 6T-3009-NNLX U.S. Environmental Protection Agency - Region 6
- - Public Notice of Final Permit Decision OCTOBER 19. 1985 This is to give notice that the U.S. Environmental Protection Agency, Region 6, i has made a final pemit decision and will issue the following ONE (1) ,
1 Proposed Pemit(s) under the National Pollutant Discharge Elimination System. ] The permit (s) will become effective 30 days from the date of this Public Notice. Any substantial changes from the Draf t Pemit are cited.
- Ttis issuance is based on a final staff review of the administrative record and comments received. A Response to Comments is available by writing to
l Ms. Ellen Caldwell i Permits Branch (6W-PS) . 1 U.S. Environmental Protection Agency - Region 6 . Interfirst Two Building l 1201 Elm Street i Dallas, Texas 75270
, (214) 767-2765 3
Any person may request an Evidentiary Hearing on this final pemit decision. i However, the request must be submitted within 30 days from the date of this Notice. The request should be in accordance with the requirements of 40 CFR 124.74
; (Federal Register Vol. 45, No. 98, Monday, May 19,1980). The original public notice contains the stay provisions of a granted evidentiary hearing request.
Further information including the administrative record may be viewed at the above address between 8 a.m. and 4:30 p.m. , Monday through Friday. j NPDES authorization to discharge to waters of the United States, j Permit No. TX0064947. i The applicant's mailing address is: Houston Lighting and Power Co. l' P.O. Box 1700 Houston, Texas 77001 } The discharge from this nuclear electric generating station is made 1 into the Colorado River in Segment 1401 of the Colorado River Basin, a , water of the United States classified for both contact and noncontact recreation and the propagation of aquatic life. The d i scha rge is located on that water approximately 10 miles north of MatagoNa Bay and 12 miles south-southwest of the City of Bay City, Matagonia County, Texas. Under the standard industrial classification (SIC) code 4911, i the applicant's activities are the construction and operation of the j South Texas Project Electric Generating Station, i i i There are substantial changes f rom the draft pemit. Part 11 conditions are revised as appropriate. ' i ! South Texas DES 2 Appendix E
- i I
. - - _ , _ . . . . _ , , , , - - . -- - ,. , -. -,-.- - .m v_--. _ - . . __.-_-__m .- ___ - -.~__ -_~ -
i This is our response. to the cocuents received on the subject draf t NPDES permit in accordance with our regulations. RESPONSE TO COMMENTS ORAFT NPDES PERMIT Permit No.: TX0064947 Permittee: Houston Lighting and' Power Company Facility Name/ Location: South Texas Project Electric Generating Station Draft Permit Public Notice Date: July 6, 1985 Prepared by: Fred Humke Issue #1 HL & P raised various comments relative to the Part 11 permit conditions.
- Response #1 The permit has been r,evised to include the Part 11 condit. ions which EPA applies in accordance with th? most recent regulations.
l Issue #2 HL & P requested revision to the minimum reservoir blowdown level from 47 MSL to 35.5 MSL, or deletion of this limitation. Response #2: EPA does not have sufficient information at this time to make this judgement. This will be considered when the permit is reissued. i South Texas DES 3 Appendix E
Permit No. TX0064947 4 AUTHORIZATION TO DISCHARGE UNDER THE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM 4 In compliance with the provisions of the Federal Water Pollution
- Control Act, as amended. (33 U.S.C . 1251 et. seq; the "Act"),
l Houston Lighting and Power Company P.O. Box 1700 Houston, Texas 77001 is authorized to discharge from a facility located at South Texas i Project Electric Generating Station, Bay City, Matagorda County, Texas to receiving waters named the Colorado River l in accordance with effluenf limitations, monitoring requir*ements and 4 other conditicns set fortt, in Parts I (10 P. ages), II (14 Pages), and III (4 pages) hereof.
. This permit shall become effective on November 19, 1985.
This permit and the authorization to discharge shall expire at midnight, December 19, 1987. Signed this 18thday of October 1985 m0& Myro#0. Knudsch, P.E. L Director, Water Management Division (6W) s i i i South Texas DES 4 Appendix E l _ _ _ _ _ . . . _ . . , _ _ . _ . _ . . _ _ _ _ . _ _ _ . _ _ _ _ - _ _ _ _ _ . . _ _ _ _ _ _ _ _ . _ _ . _ _ . _ ,_
i Permit No. TX0064947 Page 2 of . PAR 1 1 4 PART I l REQUIREMENTS FOR NPDES PERMITS 4 SECTION A. EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS - Outfall 001 i During the period beginning the effective date and lasting through the . 4 expiration date, the pennittee is authorized to discharge from Outfall(s)
- serial number (s) 001, reservoir blowdown (*1).
Such discharges shall be limited and monitored by the pennittee as specified below: i a l Effluent Characteristic Discharge Limitations . 4 Mass (lbs/ day) Other Units (Specify) Daily Avg Daily Max Daily Avg Daily Max
; Flow (MGD) N/A N/A Report 200 Temperature, degrees 35C(95F)(*2) 36.lC(97F)(*3)
N/A N/A 2 Total Residual i Chlorine (*4) N/A N/A N/A No detectable i level Effluent Characteristic Monitoring Requirements
; Measurement Sample ;
Frequency Type I Flow (MGD) Continuous Record Temperature, degrees Continuous Record Total Residual Chlorine (*4) 1/ week Grab The pH shall not be less than 6.0 standard units nor greater than 9.0 f } standard units and shall be monitored 1/ day by grab sample, t 4 There shall be no discharge of floating ~ solids or visible foani in other than trace amounts. j Samples tsken in compliance with the monitoring requirements specified 1 above shall be taken at' the following location (s): At Outfall 001, which is at a convenient point in the blowdown line prior to mixing with the Colorado River. (*1) See Part III, Paragraph 8 & 9 for Reservoir Blowdown Release Cond itirls . (*2) See Part III, Paragraph 3. i (*3) Instantaneous Maximum. : (*4) Sea Part Ill, Paragraph 4. 1 1 i South Texas DES 5 Appen' dix E l l
~_ . . . .-,...--,,__---..~_._._---.m.,__-,.___.-_.-_-,_,__.,,m_,.-,.,-.m., __,_-#, , - - - . . , . _ ~ . - . ,__.-,....__-_-wy
1 Permit No. TX006494 7 Page 3 of PART I PART I l REQUIREMENTS FOR NPOES PERMITS l SECTION A. EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS - Outfall 101 During the period beginning the effective date and lasting through the expiration date, the permittee is authorized to discharge from Outfall(s) serial number (s) 101, low volume wastewater (*1). (Discharge from neutralization basin). _ Such discharges shall be limited and monitored by the permittee as specified below: Ef fluent Characteristic Discharge Limitations Ma ss(lbs/ day) Other Units (Specify) Daily Avg Daily Max Daily Avg Daily Max Flow (MGD) N/A N/A Repo rt N/A Total Suspended Solids N/A N/A 30 mg/l 100 mg/l Oil and Grease N/A N/A 15 mg/l 20 mg/l Effluent Characteristic Monitoring Requiremen'ts Measur.ement Sample
; Frequency Type Flow (MGD) 1/ day Estimate Total Suspended Solids 1/ week Grab 011 and Grease 1/ week Grab The pH shall not be less than 6.0 standard units nor greater than 9.0 t
standard units and shall be monitored 1/ day by grab sample. There shall be no discharge of floating solids or visible foam in other than trace amounts. Samples taken in compliance with the monitoring requirements specified above shall be taken at the following location (s): At sample point 101 where low volume wastewater and previously monitored effluents are discharged from the treatment facility prior to mixing with any other 4 waste stream). ~ (*1) See Part 111, Provision 6. (*2) Since more than one source may be associated with this waste category, grab samples from each source shall be combined into a
)-
single flow weighted sample for analysis and reporting. Outfall 101, now includes boiler and steam generator blowdown previously regulated by Outfall 401 in the NPOES Permit No. TX0064947 issued December 20, 1982. ' South Texas DES 6 Appendix E i
r
. Permit No. TX0064947 Page 4 of PART I E
PART I REQUIREMENTS FOR NPDES PERMITS SECTION A. EFFLUENT LIMITATIONS AND MONITCRING REQUIREMENTS - Outfall 201 1 j During the period beginning the effective date and lasting through the i expiration date, the pennittee is authorized to discharge from Outfall(s) j serial number (s) 201, Low Volume Wastewater (*1). (Oily Waste Treatment ! System). Such discharges shall be limited and monitored by the permittee as specified below: Effluent Characteristic Discharge Limitations Mass (lbs/ day) Other Units (Specify) Daily Avg Daily Max Daily Avg Daily Max i Flow (MGD) N/A N/A Report N/A Total Suspended Solids N/A N/A 30 mg/l 100 mg/l Oil and Grease N/A N/A 15 mg/l 20 mg/l Effluent Characteristic Monitoring Requirements Measurement Sample Frequency Type i Flow (MGD) 1/ day Estimate Total Suspended Solids 1/ week Grab (*2) 011 and Grease 1/ week Grab (*2) l The pH shall not be less than 6.0 standard units nor greater than 9.0 l standard units and shall be monitored 1/ week by grab sample (*2). l l There shall be no discharge of floating. solids or visible foam in other than trace amounts. i Samples taken in compliance with the monitoring requirements specified above shall be taken at the following location (s): At sample point 201 l where low volume wastewater is discharged from the Olly Waste Treatment l System prior to mixing with any other waste stream. I (*1) See Part 111, Provision 6. (*2) Since more than one source may be associated with this waste category, grab samples from each source shall be combined into a single flow weighted sample for analysis and reporting. ! l South Texas DES 7 Appendix E
i Permit No. TX0064947 Page 5 of PART I PART ! REQUIREMENTS FOR NPDES PERMITS SECTION A. EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS - Outfall 301 i i During the period beginning the effective date and lasting through the expiration date, the permittee is authorized to discharge from Outfall(s) ; serial number (s) 301, treated sanitary sewage effluent (s). (East side facil ity) . Such discharges shall be limited and monitored by the permittee as specified below: i i Effluent Characteristic Discharge Limitations i Mass (lbs/ day) Other Units (Specify) Daily Avg Daily Max Daily Avg Daily Max Flow (MGD) N/A N/A Report Report Bloctemical Oxygen Demand (5-day) N/A N/A 20 mg/l 45 mg/l I Total Suspended Solids N/A N/A 20 mg/l 45 mg/l l Effluent Characteristic Monitoring Requirements Measurement Sample ,
- Frequency Type Flow (MGD) 1/ day Estimate
, Biochemical Oxygen Demand (5-day) 1/ week Grab Total Suspended Solids 1/ week Grab i The pH shall not be less than 6.0 stamiand units nor greater than 9.0 standard units and shall be monitored 1/ week by grab sample.
.There shall be no discharge of floating solids or visible foam in other than trace amounts.
l Samples taken in conpliance with the monitoring requirements specified above shall be taken at the following location (s): At Outfall 301 where : treated sanitary sewage effluent is discharged from the sewage treatment
~
plant prior to mixing with any otter stream. 1 South Texas DES 8 Appendix E I
Permit No. TX0064947 Page 6 of PART I PART I REQUIREMENTS FOR NPDES PERMITS SECTION A. EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS - Outfall 401 During the period beginning the effective date and lasting through the expiration date, the permittee is authorized to discharge from Outfall(s) serial number (s) 401, treated _ sanitary sewage ef fluent (s) . (West side facility). Such discharges shall be limited and monitored by the permittee as specified below: J Effluent Characteristic Discharge Limitations Mass (lbs/ day) Other Units (Specify) ' Daily Avg Daily Max Daily Avg Daily Max Flow (MGD) N/A N/A Report Report
; Biochemical Oxygen Demand (5-day) N/A N/A 20 mg/l 45 mg/l Total Suspended Solids N/A N/A 20 mg/l 45 mg/l q
Effluert Characteristic Monitoring Requirements
~
- Measurement. Sample Frequency Type l Flow (MGD) 1/ day Estimate Biochemical Oxygen Demand (5-day) 1/ week Grab
- Total Suspended Solids 1/ week Grab The pH shall not be less than 6.0' standard units nor greater than 9.0 standard units and shall be monitored 1/ week by grab sample. <
l There shall be no discharge of floating solids or visible foam in other than trace amounts. l Samples taken in compliance with the monitoring requirements specified i above shall be taken at the following location (s): At Gutfall 401: where treated sanitary sewage ef fluent is discturged f ran the treatment plant prior to mixing with any other stream, i j i i 1 South Texas DES 9 Appendix E
I
-l i l l
Permit No.. TX0064947 Page 7 of PART I 1 PART I
- REQUIREMENTS FOR NPDES PERM 115 I
)
4 j SECTION A. EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS - Outfall 501 i ) j During the period beginning the effective date and lasting through the
, expiration date, the permittee is authorized to discharge from Outfall(s)
- serial number (s) 501, metal cleaning wastewater (*1).
Such discharges shall, b.e limited and monitored by the permittee as specified below . t Effluent Characteristic . Discharge Limitations ' Mass (Ibs/ day) Other. Units (Spect fy) l Daily Avg Daily Max Daily Avg Daily Max Flow (MGD) N/A N/A Report N/A Iron, Total N/A N/A 1 mg/l 1 mg/l j Copper, Total N/A N/A 0.5 mg/l 1 mg/l l Effluent Characteristic Monitoring Requirements *
, Nasurement Sampl e.
Frequency Type i, Flow (MGD) 1/ day Estimate ; Iron, Total 1/ week Grab
~
l Copper, Total 1/ week Grab The pH shall not be less than N/A standard units nor greater than N/A
- standard units and shall be monitored N/A. >
t There shall be no discharge of floating solids or visible foam in other than trace amounts. , Samples taken in compliance with the monitoring requirements specified i above shall be taken at the following location (s): At Outfall 501 where ! metal cleaning wastes are discharged prior to mixing with any other waste ; j stream. ; i l (*l) See Part lit, Paragraph 5. i Total Suspended Solids, Oil and Grease and pil may be monitored after combination with other waste sources but before discharge to the reservoir. . i l South Texas DES 10 Appendix E l I >
Pemit No. TX0064947 Page 8 of PART I PART I REQUIREitENT5 FOR NPOES PERMITS SECTION A. EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS - Out'f all 601 During the period beginning the effective date and lasting through the expiration date, the permittee is authorized to discharge from Outfall(s) serial number (s) 601, treated sanitary sewage effluent. (Training Area Facil ity) . Such discharges shall be limited and monitored by the permittee as specified below: : Effluent Characteristic Discharge Limitations Ma ss(lbs/ day) Other Units (Specify) i Daily Avg Daily Max Daily Avg Daily Max I Flow (MGO) N/A N/A Report Report Biocremical Oxygen l Demand (5-day) N/A N/A 20 mg/l . 45 mg/l Total Suspended Solids N/A N/A 20 mg/l 45 mg/l 4 1 Ef fluent Characteristic Monitoring Requirements , hasurement Sample Frequency Type Flow (MGD) 1/ day Estimate Biochemical Oxygen Demand (5-day) 1/ week Grab Total Suspended Solids 1/ week Grab e The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units and shall be monitored 1/ week by grab sample. There shall be no discharge of floating solids or visible foam in other than trace amounts. ! Samples taken in compliance with the monitoring requirements specified above shall be taken at the following location (s): At Outfall 601 where treated sanitary sewage effluent is discharged from the sewage treatment plant prior to mixing with any other stream. l I i South Texas DES 11 Appendix E l
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l i Permit No. TX0064947 Page 9 of PART I PART I I REQUIREMENTS FOR NPDES PERMITS SECTION A. EFFLUENT LINITATIONS AND MONITORING REQUIREMENTS - Outfall 002 During the period beginning the effective date and lasting through the expiration date, the permittee is authorized to discharge from Outfall(s) serial number (s) 002, Sewage Treatment Plant Discharge. (This Outfall was designated previously under Outfall 301 in NPDES Permit No. TX0064947 effective December 20' 1982). , Such discharges shall- be limited and monitored by the permittee as specified below: Effluent Characteristic Discharge Limitations Mass (Ibs/ day) Other Units (Specify) Daily Avg Daily Max Daily Avg Daily Max Flow (MGD) N/A N/A Report Report Biochemical Oxygen Demand (5-day) 4.5(10) N/A 20 mg/l 45 mg/l Total Suspended Solids 4.5(10) N/A 20 mg/l 45 mg/l i Effluent Characteristic Monitoring Requirements Nasurement Sample Frequency Type Flow (MGD) 1/ day Instantaneous Biochemical Oxygen Demand (5-day) 1/ week Grab Total Suspended Solids 1/ week Grab The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units and shall be monitored 1/ week by grab sample. ,
- There shall be no discharge of floating solids or visible foam in other a
than trace amounts. ! Samples taken in compliance with the monitoring requirenents specified above shall be taken at the following location (s): At Outfall 002, where the construction stage sewage treat;nent plant discharges prior to mixing with any other waters. This waste stream shall be chlorinated suf ficiently to maintain a 1.0 mg/l chlorine residual af ter at least 20 minutes contact time based on peak flow conditions and shall be monitored 2/ week by grab sample. i South Texas DES 12 Appendix E l _ _ . ,_ _ _ . _. ._. _ -.__ _.. _ __ _ _ _ _ . _ _ . . _ _ _ _ ~ _ . _ _ _ .
Pemit No. TX0064947 Page 10 of P/ RI I SECTION B. SCHEDULE OF COMPLIANCE The pemittee shall achieve compliance with the effluent limitations specified for discharges in accontance with the following schedule: None. 13 Appendix E South Texas DES
1 l l Pe rm i t No . TX0064947 Page 1 of PART.!! l PART !! STANDARD CONDITIONS FOR NPDES PERMITS SECTION A. GENERAL CONDITIONS
- 1. Duty to Comply The permittee must comply with all conditions of this permit. Any permit noncompliance constitutes a violation of the Clean Water Act and is i grounds for enforcement action; for permit termination, revocation and reissuance, or modification; or for dental of a permit renewal application.
- 2. Penalties for Violations of Permit Conditions The Clean Water Act provides that any person who violates a permit condition implementing Sections 301, 302, 306, 307, 308, 318, or 405 of the Clean Water Act is subject to a civil penalty not to exceed $10,000 per day of such violation. Any person who willfully or negligently violates
- permit conditions inplementing Sections 301, 302, 306- 307, or 308 of the ,
Clean Water Act is subject to a fine of not less than $2,500 nor more than $25,000 per day of violation, or by imprisonment for not more than 1 year, or both.
- 3. Permit Actions 1
This permit may be modified, revoked and reissued, or terminated for cause including, but not limited to, the following:
- a. Violation of any terms or conditions of this permit;
- b. Obtaining this permit by misrepresentation or failure to disclose fully all relevant facts; or
- c. A change in any condition that requires either a temporary or a permanent recuction or elimination of the authorized discharge; or
- d. A determination that the permitted activity endangers human health or the environment and can only be regulated to acceptable levels by permit modification or termination.
t The filing of a request by the permittee for a permit modification, revocation and reissuance, or termination, or a notification of planned changes or anticipated noncompliance, does not stay any permit condition. d South Texas DES 14 Appendix E
Page 3 of PART Il Pemit No. TX0064947
- 9. Severability The provisions of this permit are severable, and if any provision of this permit or the application of any provision of this permit to ,
l any circumstance is held invalid, the application of such provision , to other circumstances, and the remainder of this permit, shall not i be affected thereby. 4
- 10. Definitions The following definitions shall apply.unless otherwise specified in this permit:
- a. " Daily Discharge" means the discharge of a pollutant measured during a calendar day or any 24-hour period that reasonably represents the calendar day for purposes of sampling. For pollutants with limitations expressed in terms of mass, the i " daily discharge" is calculated as the total mass of the pollutant discharged over the sampling day. For pollutants with limitations expressed in other units of measurement, the j " daily discharge" is calculated as the average measurement 1 of the pollutant over the sampling day. " Daily discharge"
- determination of concentration made using a composite sample i shall be the concentration of the composite sample. When grab samples are used, the " daily discharge" detennination
- of concentration shall be the arithmetic average (weighted by flow value) of all samples collected duritig that sampling day.
i b. " Daily Average" discharge limitation means the highest allowable average of " daily discharges" over a calendar month, calculated as the sum of all " daily discharges" measured during a calendar month divided by the number of " daily discharges" measured during that month.
- c. " Daily Maximum" discharge limitation means the highest allow-able " daily discharge" during the calendar month.
i 4 South Texas DES 15 Appendix E f
Permit NJ. TX0064947 Page 5 of PART 11 l
- c. Notice (1) Anticipated bypass. If the permittee knows in advance of the need for a. bypass, it shall submit prior notice, if possible at least ten days before the date of-the bypass.
(2) Unanticipated bypass. The permittee shall submit notice of an unanticipated bypass as required in Section D, paragraph 6 (24 . hour notice).
- d. Prohibition of bypass.
(1) Bypass is prohibited, and the Director may take enforcement action against a permittee for bypass, unless: (a) Bypass was unavoidable to prevent loss of life, personal injury, or severe property damage;
; (b) There were no feasible alternatives to the bypass, such as the use of auxiliary treatment facilities, retention of untreated wastes, or maintenance during normal periods of equipment downtime. This condition is not satisfied if adequate back-up equipment should have been installed in the exercise of reasonable engineering judgment to prevent a bypass which occured during normal periods of equipment downtime or preventive maintenance; and (c) The permittee submitted notices as required under Section B, paragraph 4.c.
(2) The Director may approve an anticipated bypass, after considering its adverse effects, if the Director determines that it will meet the three conditions listed above in 2 Section B, paragraph 4.d.(1).
- 5. Upset Conditions
- a. Definition. " Upset" means an exceptional incident in which there is unintentional and temporary noncompliance with i technology-based permit ef fluent limitations because of factors beyond the reasonable control of the permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventive maintenance, or careless or improper operation.
1 South Texas DES 16 Appendix E
j. Pennit No. TX0064947 Page 7 of PART II SECTION C. MONITORING AND RECORDS
- 1. Representative Sampling i.
i Samples and measurements taken as required herein shall be representative of. the volume and nature of the monitored dishcarge. All samples
- . shall be taken.at the monitoring points specified in this permit and, i unless otherwise specified, before the effluent joins or is diluted
- by any other wastestream, body of water, or substance. Monitoring
< points shall not be changed without notification to and the approval of_the Director.
I 2. Flow Measurements 1 1 Appropriate flow measurement devices and methods consistent with [ accepted scientific practices shall be selected and used to ensure the accuracy and reliability of measurements of the volume of monitored i i discharges. The devices shall be installed, calibrated, and maintained to. insure that the accuracy of the measurements are consistent with the accepted capability of that type of device. Devices selected j shall be capable of measuring flows with a maximum deviation of less
; than + 107, from true discharge rates throughout the range of expected discharge volumes. Guidance in selection, installation, calibration.
l and operation of acceptable flow measurement devices can be obtained from the following references:
! a. "A Guide to Methods and Standards for the Measurement of Water Flow", U.S. Department of Comerce National Bureau of ; Standards, NBS Special Publication 421, May 1975, 97 pp.
j (Available from the U.S. Government Printing Office, Washington,
; D.C. 20402. Order by 50 catalog No. C13.10:421). ! b. " Water Measurement Manual", U.S. Department of Interior,
, Bureau of Reclamation, Second Edition, Revised Reprint. l 1974, 327 pp. (Available from the U.S. Government Printing 1 Office, Washington, D.C. 20402. Order by Catalog No. l 127.19/2:W29/2, Stock No. S/N 24003-0027). i, 1 ] c. " Flow Measurement in Open Channels and Closed Conduits". U.S. ; J Department of Comerce, National Bureau of Standards, NBS Special Publication 484, October 1977, 982 pp. (Available in paper copy or microfiche from National Technical Information I Service (NTIS), Springfield, VA 22151. Order by NflS No. PB-273 535/5ST). ; i i d. " NPDES Compliance Sampling Manual". U.S. Environmental j Protection Agency, Office of Water Enforcement, Publication i 1 South Texas DES 17 Appendix E i
'9" Permit No. TX0064947 t.
l
- 7. Averaging of Measurements 1
Calculations for all limitations which require averaging of measurements shall utilize an arithmetic mean unless otherwise specified by the Director in the permit. l 8.-Retention of Records i The permittee shall retain records of all monitoring information, including all calibration ~ and maintenance records and all original strip chart recordings for continuous monitoring instrumentation, copies of all reports required by
- this permit, and records of all data used to complete the application for this permit, for a period of at least 3 years from the date of the sample! ;
measurement, report, or application. This period may be extended by request of i
. the Director at any time. !
i 9. Record Contents Records of monitoring information shall include:
- a. The date, exact place, and time of sampling or measurements; i . ,
i b. The individual (s) who performed the sampling or measurements; ]
- c. The date(s) analyses were performed;
- d. The individual (s) who performed the analyses;
- e. The analytical techniques or methods used; and i
- f. The results of such analyses.
I 10. Inspection and Entry The permittee shall allow the Director, or an authorized representative, upon r the presentation of credentials and other documents as may be required by law, to: i a. Enter upon the permittee's premises where a regulated facility i or activity is located or conducted, or where records must be kept under the conditions of this permit; i
- b. Have access to and copy, at reasonable times, any records that must be kept under-the conditions of this permit; j c. Inspect at reasonable times any facilities, equipment (including monitoring and control equipment), practices, or operations regulated or required under this permit; and i d. Sample or monitor at reasonable times, for the purposes of l assuring permit compliance or as otherwise authorized by the j Clea.. L te. Au . , . . . , su'ustances or parameters at any location.
- South Texas DES 18 Appendix E l
t Page 11 of PART 11 Permit No. TX0064947 i
- 6. Twenty Four Hour Reporting !
4 The permittee shall report any noncompliance which may endanger health j or the environment. Any information shall be provided orally within
- 24 hours from the time the permittee becomes aware of the circumstancess :
3 A written submission shall also be provided within 5 days of the time the permittee becomes aware of the circumstances. The written submission shall contain a description of the noncompliance and its cause; the period of noncompliance, including exact dates and times,
.and if the noncompliance has not been corrected, the anticipated time it is expected to cont nue; and steps taken or planned to reduce, [
eliminate, and prevent reoccurrence of the noncompliance. The Director may waive the written report on a case-by-case basis if the oral report has been received within 24 hours. f The following shall be included as information which must be reported within 24 hours:
- a. Any unanticipated bypass which exceeds any effluent limitation j in the permit.
- b. Any upset which exceeds any effluent limitation in the permit.
?
i c. Violation of a maximum daily discharge limitation for any of j the pollutants listed by the Director in Part III of the permit , to be reported within 24 hours. l t
- 7. Other Noncompliance !
I The permittee shall report all instances of noncompliance not reported ; under Section D, paragraphs 4, 5, and 6, at the time monitoring reports are submitted. The reports shall contain the information listed in Section D, paragraph 6.
- 8. Changes in Discharges of Toxic Substances The permittee shall notify the Director as soon as it knows or has
- reason to believe: l
- a. That any activity has occured or will occur which would result ,
in the discharge, in a routine or frequent basis, of any toxic pollutant which is not limited in the permit, if that
, discharge will exceed the highest of the " notification levels" l described in 40 CFR Part 122.42(a)(1) [48 FR 14153, April 1,
~
1983, as amended at 49 FR R 38046, September 26,1984]. l b. That any activity has occured or will occur which would { result in any discharge, on a non-routine or infrequent basis,
; of a toxic pollutant which is not limited in the permit, if South Texas DES 19 Appendix E f
Permit No. TX0064947 Page 13 of PART II (3) For a nunicipality, State, Federal, or other public agency: by either a principal executive officer or ranking elected official . For purposes of this section. 1 a principal executive officer of a Federal agency includes: (i) The chief executive officer of the agency, or (ii) a senior executive officer having responsibility for the overall operations of a principal geographic unit of the agency.
- b. All reports required by the permit and other information.
requested by the Director shall be signed by a person described i above or by a duly authorized representative of that person. A person is a duly authorized representative only if: (1) The authorization is made in writing by a person described above. l (2) The authorization specifies either an individual or a l position having responsibility for the overall operation of the regulated facility or activity, such as the position of plant manager, operator of a well or a well field, superintendent, or position of equivalent responsibility, or an individual or position having overall responsibility l for environmental matters for the company. A duly authorized representative may thus be either a named individual or any individual occupying a named position; l and (3) The written authorization is submitted to the Director.
- c. Certification. Any person signing a document under this section shall make the following certification:
"I certify under penalty of law that this document and all attachments were prepared under the direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for-submitting false information, including the possibility of fine and imprisonment for knowing violations."
South Texas DES 20 Appendix E
Pe rmi t No . TX0064947 Page 1 of PART 111 PART 111 OTHER CONDITIONS
- 1. There shall be no discharge of polychlorinated biphenyl transformer l fl uid .
- 2. The " daily average" concentration means the arithmetic average (weighted by flow.value) of al.1 the daily determinations of
( concentration made during a calendar month. Daily determinations of concentration made using a canposite sanple shall be the concentration of the composite sample. When grab samples are used , the daily determination of concentration shall be the arithmetic average (weighted by flow value) of all the samples collected during that calendar day. The " daily maximum" concentration means the daily determination of l concentration for any calendar day.
- 3. Daily average temperature is defined as the flow weighted average temperature (FWAT) and shall be computed and recorded on a daily l basis. FWAT shall be c,omputed at equal time intervals,not greater l
than two hours. The method of calculating FWAT is as follows: FWAT = SUMMATION (INSTANTANE0US FLOW X INSTANTANEOUS TEMPERATURE SUMMATION (INSTANTANEOUS TLOW)
- 4. The term " total residual chlorine" (or total residual oxidants for intake water with bromides) means the value obtained using the amperometric method for total residual chlorine described in the latest edition of " Standard methods for the Examination of Water and Wastewater".
- 5. The term " metal cleaning wastes" shall mean any cleaning ~ compounds, rinse waters, or other waterbone residues derived f rom cleaning any metal process equipment including , but not limited to, boiler tube cleaning, boiler fireside cleaning and air preheater cleaning.
- 6. The term " low-volume w3stesources" means wastewaters f rom, but not limited to; wet scrubber air pollution control system, ion exchange water treatment system, water treatment, evaporator blowdown, laboratory and sampling streams, floor drainage, cooling tower basin cleaning wastes and blowdown from recirculating house service water systems.
- 7. As a provision of this permit, the applicant is subject to the requirements of PL 92-500 Section 316(b).
South Texas DES 21 Appendix E
Permi t No . TX0064947 Page 2 of PART !!! PART !!! OTHER CONDITIONS
- 8. Blowdown is limited to 12.5 percent of the dif ference between'the Bay City gage flow and makeup' diversion for the STP. During June, July, and August, the percentage is limited _ to 10 percent. Blowdown is pemitted only when the remaining river flow, after makeup diversion, is 800 cfs. After the allowable blowdown is detemined, the reservoir water level and the river flow opposite the point of blowdown will serve as constraints to detemine whether the blowdown is allowed. If either the reservoir water level is less t'han elevation 47 MSL or the tidal river flow at the point of blowdown is less than a prescribed value, blowdown is not pemitted. Blowdown is limited to a maximum flow of 308 cfs.
- 9. "The required number of ports through which discharge occurs is a function of blowdown rate as shown in the chart below. These blowdown conditions are described graphically on pages 25 and 26 of 26."
Blowdown Rate Number of Ports cfs required 80-88 2 1 88-132 3 132-176 4 176-220 5 220-264 6 264-308 7
- 10. In accordance with information submitted by H.L. & P. on June 28, 1982, tre intake structure is approved by Best Available Technology in accordance with Section 316 (b) of the CWA.
v;
\, b South Texas DES 22 Appendix E
f
~ Penn i t No . TX0064947 Page 3 of PART 111
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30 I f,000 i /. *500 2.000 2,500 . EEQUlFEO Qq,yg, i4T PO'NT T B'_OY!DOWt1 G%PH B t South Texas DES 24 Appendix E
t i 4 APPENDIX F , , ENVIRONMENTAL IMPACTS OF POSTULATED ACCIDENTS L F.1 : Plant Accidents The staff has considered the potential radiological impacts on the environment of possible accidents at the South Texas plant site in accordance with the } June 13, 1980, Statement of Interim Policy issued by the NRC. The discussion below reflects the staff's considerations and conclusions.
- Section F.2 deals with general characteristics of nuclear power plant accidents, including a brief summary of safety measures incorporated into the design to
~
minimize the probability of their occurrence and to mitigate the consequences . should acciden?: occur. Also described are the important properties of radio-
' active materic and the pathways by which they could be transported to become environmental hazards. Potent.ial adverse health effects and societal impacts associated with actions to avoid such health effects as a result of air, water, and ground contamination from accidents are also identified.
Next,~ actual experience with nuclear power plant accidents and their observed health effects and other societal impacts are described. This is followed by a summary review of safety features of the South Texas facilities and of the site that act to mitigate the consequences of accidents. The results of calculations of the potential consequ'ences of accidents that have b.een postulated within the design basis -are then given. Also described are.the results.of calculations for the South Texas site using probabilistic methods to estimate the possible impacts and-the risks associated with severe accident sequences of exceedingly low probability of occurrence. F. 2 General Characteristics of Accidents s The term " accident'" as used in this section, refers to any unintentional event not addressed in Section 5.9.3 of the main body of this environmental statement that~results in a release of radioactive materials into the environment. The i predominant focus, therefore, is on events that can lead to releases substan-tially.in excess of permissible limits for normal operation. Normal release limits are specified in the Commission's regulations in 10 CFR 20 and 10 CFR 50, Appendix I.
.There are several features that combine to reduce the risk associated with acci-dents at nuclear power plants. Safety features in design, construction, and operation, constituting the first line of defense, are to a very large extent de-voted to preventing the release of these radioactive materials from their normal places of confinement within the plant. There are also a number of additional lines of defense that are designed to mitigate the consequences of failures in the first line. Descriptions of-these features for South Texas are in the appli-cant's FSAR. The most important mitigative features are described in Sec-tion F.4(1) below. l South Texas DES 1 Appendix F .~. - _ _ _ _ _ . _ _ _- . . - ~ - . . _ . . _ . _ _ _ . _ _ _ ~ _ _ _ _ -
i l These safety features are designed taking into consideration the specific loca- I tions of radioactive materials within the plant: their amounts; their nuclear, physical, and chemical properties; and their relative tendency to be transported into, and for creating biological hazards in, the environment. (1) Fission Product Characteristics -, By far the largest inventory of radioactive material in a nuclear power plant is produced as a byproduct of the fission process and is located in the uranium oxide fuel pellets in the reactor core in the form of fission products. During periodic refueling shutdowns, the assemblies containing these fuel pellets are transferred to a spent-fuel storage pool so that the second largest inventory of radioactive material is located in this storage area. Much smaller inventories of radioactive materials are also normally present in the water that circulates in the reactor coolant system and in the systems used to process gaseous and liquid radioactive wastes in the plant. Table F.1 lists the radionuclides that could be expected in each of the South Texas Units 1 and 2 reactor core. These radioactive materials exist in a variety of physical and chemical forms. Their potential for dispersion into the environment depends not only on mechani-cal forces that might physically transport them, but also on their inherent properties, particularly their volatility. The majority of these materials exist as nonvolatile solids over a wide range of temperatures. Some, however, are relatively volatile solids and a few are gaseous in nature. These character-istics have a significant bearing on the assessment of the environmental radio-logical impact of accidents. The gaseous materials include radioactive forms of the chemically inert noble gases krypton and xenon. These have the highest potential for release into the atmosphere. If a reactor. accident were to occur involving degradation of the fuel cladding, the release of substantial quantities of these radioactive gases from the fuel is a virtual certainty. Such accidents are low frequency, but credible events (see Section F.3). For this reason the safety analysis of each nuclear power plant incorporates a hypothetical design-basis accident that postu-lates the release of the entire contained inventory of radioactive noble gases from the fuel into the containment structure. If the noble gases were further released to the environment as a possible result of failure of safety features, the hazard to individuals from these noble gases would arise predominantly through the external gamma radiation from the airborne plume. The reactor con-tainment structure is designed to minimize this type of release. Radioactive forms of iodine are produced in substantial quantities in the fuel by the fission process, and in some chemical forms they may be quite volatile. For these reasons, they have traditionally been regarded as having a relatively high potential for release (50% of the inventory) from the fuel. If the radio-nuclides are released to the environment, the principal radiological hazard associated with the radioiodines is ingestion into the human body and subse-quent concentration in the thyroid gland. Because of this, the potential for release of radiciodines to the atmosphere is reduced by the use of special sys-tems designed to retain the iodine. The chemical forms in which the fission product radioiodines are found are gen-erally solid materials at room temperatures, so they have a strong tendency to j condense (or " plate out") on cooler surfaces. In addition, most of the iodine l l South Texas DES 2 Appendix F i l l
compounds are quite soluble in, or chemically reactive with, water. Although these properties do not inhibit the release of radioiodines from degraded fuel, they would act to mitigate the release from the containment structure that has large internal surface areas and that contains large quantities of water as a result of an accident. The same properties affect the behavior of radio-iodines that may " escape" into the atmosphere. Thus, if rainfall occurs during a release, or if there is moisture on exposed surfaces (for example, dew), the radiciodines will show a strong tendency to be absorbed by the r.;oisture. Other radioactive materials formed during the operation of a. nuclear power plant have lower volatilities and, therefore, by comparison with the noble gases and iodines, have a much smaller tendency to escape from degraded fuel unless the temperature of the fuel becomes very.high. By the same token, such materials, if they escape by volatilization from the fuel, tend to condense quite rapidly to solid form again when they are transported to a lower temperature region and/or dissolve in water when it is present. The former mechanism can result in production of some solid particles of sufficiently small size to be carried some distance by a moving stream of gas or air. If such particulate materials are dispersed into the atmosphere as a result of failure of the containment barrier, they will tend to be carried downwind and deposit on surface features by gravitational settling (fallout) or by precipitation (washout or rainout), where they will become " contamination" hazards in the environment. All of these radioactive materials exhibit the property of radioactive decay with characteristic half-lives ranging from fractions of a second to many days or years. Many of them decay through a sequence or chain of decay processes and all eventually become stable (nonradioactive) materials. The radiation emitted during these decay processes renders the radioactive materials hazardous. (2) Meteorological Considerations Two separate analyses of accident sequences are performed by the staff. One analysis, the determination of the consequences of certain accidents referred to as design-basis accidents, is performed for the staff's safety evaluation report. This analysis is performed to ensure that the doses to any individual at the exclusion area boundary (EAB) over a period of twa hours, or at the outer boundary of the low population zone (LPZ) Mnq the entire period of plume passage, will not exceed the siting dose guidelines of 25 rem to the whole body or 300 rem to the thyroid, pursuant to 10 CFR 100. This analysis is used to examine site suitability (10 CFR 100) and the mitigative capability of certain plant safety features (10 CFR 50). The atmospheric dispersion model for this evaluation, as described in Regulatory Guide 1.145, uses onsite meteorological data (typically, a multi year period of record) considered representative of the site and vicinity to calculate relative concentrations (x/Q) which will be exceeded no more than 0.5% of the time in any one sector (22 ) and no more than 5% of the time for all sectors (360 ) at the EAB and LPZ. The second analysis of accident consequences is reported herein and considers a spectrum of release categories (including severe accidents) and actual meteorological conditions from a representative one year period of record of onsite data. From this one year period (8670 consecutive hours) of hourly averaged meteorological observations (wind speed, atmospheric stability, and precipitation), 91 time sequences are used to estimate the dispersion and de- , position of radioactive material from each release category into each of 1 South Texas DES 3 Appendix F
16 sectors corresponding to the 22 sectors used to report wind direction. The sampling of meteorological data is performed in such a way that all hourly data appear at some time during at least one of the time sequences, and that favorable, unfavorable, and typical atmospheric dispersion conditions are considered. The
~
coupling of 91 time sequences and 16 directions produces 1456 sets of computed consequences for each release category. The probability associated with each set is the product of the probability of the release categories multiplied by the annual probability of the wind blowing into a given sector, divided by 91 to represent the equal likelihood of the meteorological samples. The diversity of meteorological conditions sampled is principally responsible for the general shape of the probability di3tributions given in Figures F.3 through F.7. Com-binations of the worst severe accident release category and the most unfavorable meteorological conditions sampled are represented by the extreme of the distri-bution on the bottom right of each of the plots presented. A detailed descrip-
' ion of the atmospheric dispersion model is contained in NUREG-75/014 (formerly . ui-1400), Appendix VI.
(3) Exposure Pathways The radiation exposure (hazard) to individuals is determined by~their proximity to the radioactive materials, the duration of exposure, and factors that act to shield the individual from the radiation. Pathways for radiation and the transport of radioactive materials that lead to radiation exposure hazards to humans are generally the same for accidental as for " normal" releases. These are depicted in Figure F.1. There are two additional possible pathways that could be significant for accident releases that are not shown in Figure F.1. One of these is the fallout of radioactivity initially carried in the air onto open bodies of water or onto land and eventual runoff into open water bodies. The second would be unique to an accident that results in temperatures inside the reactor core sufficiently high to cause melting and subsequent penetration of the basemat underlying the reactor by the molten core debris. This creates the potential for the release of radioactive material into the hydrosphere via groundwater. These pathways may lead to external exposure to radiation and to internal exposure if radioactive material is contacted, inhaled, or ingested from contaminated food or water. It is characteristic of these pathways that during the transport of radioactive material by wind or by water the material tends to spread and disperse, like a plume of smoke from a smokestack, becoming less concentrated in larger volumes of air or water. The result of these natural processes is to lessen the inten-sity of exposure to individuals downwind or downstream of the point of release, but they also tend to increase the number who may be exposed. For a release into the atmosphere, the degree to which dispersion reduces the concentration in the plume at any downwind point is governed by the turbule1ce characteristics of the atmosphere, which vary considerably with time and from place to place. This fact, taken in conjunction with the variability of wind direction and the presen e or absence of precipitation, means that accident consequences are very much dependent upon the weather conditions existing at the time. (O Health Effects The cause-and-effect relationships between radiation exposure and adverse health effects are quite complex (National Research Council,1979; Land,1980). South Texas DES 4 Appendix F
Whole-body radiation exposure resulting in a dose greater than about 25 rem over a short period of time (hours) is necessary before any physiological effects to an individual are clinically detectable shortly thereafter. Ooses about 10 to 20 times larger, also received over a relatively short period of time (hours to a few days), can be expected to cause some fatal injuries. At the severe but extremely low probability end of the accident spectrum, exposures of these magnitudes are theoretically possible for persons in proximity of the plant if measures are not or cannot be taken to provide protection, such as by sheltering or evacuation. Lower levels of exposures may also constitute a health risk, but the ability to define a cause-and-effect relationship between any given health effect and a known exposure to radiation is difficult, given the backdrop of the many other possible reasons why a particular effect is observed in a specific individual. For_this reason, it is necessary to assess such effects on a statistical basis. Such effects include randomly occurring cancer in the exposed population and genetic changes in future generations after exposure of a prospective parent. Occurrences of cancer in the exposed population may begin to develop only after a lapse of 2 to 15 years (latent period) from the time of exposure and continue over a period of about 30 years (plateau period). However, in the case of expo-sure of fetuses (in utero), occurrences of cancer may begin to develop at birth (no latent period) and end at age 10 (that is, the plateau period is 10 years). The occurrence of cancer itself is not necessarily indicative of fatality. The health consequences model used in this assessment is based on the 1972 BEIR Report of the National Academy of Sciences (NAS) BEIR I report (1972). Most authorities agree that a reasonable--and probably conservative- estimate of the randomly occurring number of health effects of low levels of radiation exposure to a large number of people is within the range of about 10 to 500 potential cancer deaths per million person-rem (although, zero is not excluded by the data). The range romes from the NAS BEIR III report (1980), which also indicates a probable value of about 150. This value is virtually identical to the value of about 140 used in the current NRC health effects models. In addition, approx-imately 220 genetic changes per million person-rem would be projected by BEIR III over succeeding generations. That also compares well with the value of about 260 per million person-rem currently used by the NRC staf f, which was computed as the sum of the risk of specific genetic defects and risk of defects with complex etiology (causes). (5) Health Effects Avoidance Radiation hazards in the environment tend to disappear by the natural process of radioactive decay. Where the decay process is a slow one, however, and where the material becomes relatively fixed in its location as an environmental con-taminant (such as in soil), the hazard can continue to exist for a relatively long period of time--months, yearn, or even decades. Thus, a possiM e environ-mental. societal impact of severe accidents is the avoidance of the health hazard rather than the health hazard itself, by restrictions on the use of the contam-inated property or contaminated feodstuffs, milk, and drinking c v The poten-
'tial economic impacts that this can cause are discussed below.
F. 3 Accident Experience and Observed Impacts i The evidence of' accident frequency and impacts in the past is a useful indicator of future probabilities and impacts. As of October 1985, there were 95 commer-cial nuclear power reactor units licensed for operation in the United States South Texas DES 5 Appendix F
I with power generating capacities ranging from 50 to 1180 megawatts electric (MWe). South Texas plants are designed for an electric power output to 1250 MWe. ; The combined experience with these operating units represents approximately 800 reactor years of operation over an elapsed time of about 24 years. Accidents have occurred at several of these facilit.es (0ak Ridge, 1980; NUREG-0651; Thompson and Beckerley,.1964). Some of these accidents have resulted in re-
- leases of radioactive material.to the environment, ranging from very small frac-i tions of a curie to a few million curies. None is known to have caused any radiation injury or fatality to any member of the public, nor any significant ,
- contamination of the environment. This e;:perience base is not large enough to permit. reliable statistical prediction of accident probabilities. It does, however, suggest that significant environmental impacts caused by accidents are very unlikely to occur over time periods of a few decades.
i ! Melting or severe degradation of reactor fuel has occurred in only one of these ! uaits, during the accident at Three Mile Island Unit 2 (THI-2) on March 28, 1979. It has been estimated that about 2.5 million curies of noble gases (about 0.9% i of the core inventory) and 15 curies of radiciodine (about 0.00003% of the core inventory) were released to the environment at IMI-2 (NUREG/CR-1250).* No other i
- radioactive fission products were released in. measurable quantity. It has been estimated that the maximum cumulative offsite radiation dose to an individual was less than 100 millirem'(NUREG/CR-1250; President's Commission, 1979). The i total population exposure has been estimated to be in the range from about 1000 to 5000 person-rem (this range is discussed on page 2 of NUREG-0558). This ex- ;
posure could statistically produce between zero and one additional fatal cancer - over the lifetime of the population. The same population receives each year , from natural. background radiation about 240,000 person-rem, and approximately a ' i half-million cancer deaths are expected in this group (NUREG/CR-1250; President's Commission, 1979) primarily from causes other than radiation. Trace quantities (barely above the limit of detectability) of radiciodine were found in a few samples of ' milk produced in the area. No other food or water supplies were
- affected.
j Accidents at U.S. nuclear power plants have also caused occupational injuries i and a few fatalities, but not attributed to radiation exposure. Individual
- worker exposures have ranged up to about 4 rem as a direct consequence of reac-j tor accidents (although there have been higher exposures to individual workers
- as a result of other unusual occurrences). However, the collective worker ex-posure levels (person-rem) from accidents are a small fraction of the exposures.
i experienced during routine operation; routine exposures range from 440 to 1300 person-rem per year in a PWR and 740~ to 1650 person-rem per year in a BWR per i reactor year. i Accidents have also occurred at other nuclear facilities in the United States and in other countries (0ak Ridge, 1980; Thompson and Beckerley, 1964). Because of inherent differances in design, construction, operation, and purpose of most of these other facilities, their accident record has only indirect relevance to current nuclear power plants. Melting of reactor fuel occurred in at least seven of these accidents, including the one in 1966 at Enrico Fermi Atomic Power Plant Unit 1. Fermi Unit 1 was a sodium-cooled fast breeder demonstration 3 reactor designed to generate 61 MWe. The damages were repaired and the reactor reached full power 4 years after the accident. It operated successfully and r ! *Also referred to as the Rogovin report. 1 South Texas DES 6 Appendix F 1 _ _ _ _ _ _- ____.._________._..______._~______-__-_____:.____________ - -
completed its mission in 1973. The. Fermi accident did not release any radio-activity to the environment. A reactor accident in 1957 at Windscale, England, released a significant quan-tity of radioiodine, approximately 20,000 curies, to the environment (United Kingdom Atomic Energy Office, 1957). This reactor, which was not operated to generate electricity, used air rather than water to cool the uranium fuel. During special operation to heat the large amount of graphite in this reactor (characteristic of graphite-moderated reactor), the fuel overheated and radio-iodine and noble gases were released directly to the atmosphere from a 123-m (405-ft) stack. Milk produced in a 518-km2 (200-mi2) area around the facility was impounded for up to 44 days. The United Kingdom National Radiological Pro-tection Board (1957) estimated that the releases may have caused as many as 260 cases of thyroid cancer, about 13 of them fatal, and as many as 7 deaths from other cancers or hereditary diseases. This kind of accident cannot occur in a water-moderated-and-cooled reactor like the South Texas units, however. F.4 Mitigation of Accident Consequences Pursuant to the Atomic Energy Act of 1954, as amended, the NRC is conducting a safety evaluation of the application to operate the South Texas Project Units 1 and 2. Although this safety evaluation will contain more detailed information on plant design, the principal design features are presented in the following section. (1)' Design Features The South Texas Project Units 1 and 2 contain features designed to prevent acci-dental release of radioactive fission products from the fuel and to lessen the consequences should such a release occur. Many of the design and operating specifications of these features are derived from the analysis of postulated events known as design-basis accidents. These accident preventive and mitiga-tive features are collectively referred to as engineered safety features (ESF). The possibilities or probabilities of failure of these systems is incorporated in the assessments discussed in Section F.5. The large steel-lined concrete containment building is a passive mitigating system which provides a virtually leaktight barrier to minimize the escape of fission products to the environment in the unlikely event of-a fission product release inside containment. Safety injection systems are incorporated to pro-vide cooling water to the reactor core during an accident to prevent or minimize fuel damage. Cooling fans provide heat removal capability inside the contain-ment following steam release in accidents and help to prevent containment failure from overpressure. Similarly, the containment spray system is designed to spray cool water into the containment atmosphere. The spray water also contains an additive (sodium hydroxide) which can chemically react with certain forms of airborne radioiodine to help remove them from the containment atmosphere and minimize their release to the environment. All the mechanical systems mentioned above are supplied with emergency power from onsite diesel generators in the event that normal offsite statien power is interrupted. The fuel handling building also has accident-mitigating systems. The safety-grade exhaust air subsystem of the ventilation system contains both charcoal and South Texas DES 7 Appendix F
._ - - -=
high-efficiency particulate filters.~ The ventilation system is also designed to keep the area around the spent-fuel pool below the prevailing barometric pressure
; during the fuel handling operations to minimize the outleakage through building openings. Upon detection of high radiation, exhaust air is routed through the l
filter units and most of the radioactive iodine and particulate fission products would be removed from the flow stream before exhausting to the outdoor atmosphere. There are features of the plant that are necessary for its. power generation function that can also play a role in mitigating certain accident consequences. For example, the main condenser, although not classified as an engineered safety l feature, can act to mitigate the consequences of accidents involving leakage
, from the primary to the secondary side of the steam generators (such as steam '
l generator tube ruptures). If normal offsite power is maintained, the ability ~ of the plant to send contaminated steam to the condenser instead of releasing it through the safety valves or atmospheric dump valves can significantly reduce the amount of water-soluble radionuclides released to the environment. 2 Much more extensive discussions of the safety features and characteristics of South Texas Units 1 and 2 may be found in the FSAR. The staff evaluation of j these features will be presented in the South Texas Units 1 and 2 SER. In addi-tion, the implementation of the lessons lea'rned from the TMI-2 accident--in the
' form of improvements in design, procedures, and operator training--will signi-ficantly reduce the likelihood of a degraded-core accident which could result in large releases of fission products to the containment. Specifically, the
,! applicant will be required to meet those TMI-2-related requireirents specified in NUREG-0737. (2) Site Features i The NRC's reactor site criteria, 10 CFR 100, require that every power reactor site have certain characteristics that tend to reduce the risk and potential impact of accidents. The discussion that follows briefly describes the South Texas site characteristics and how they meet these requirements. - First, the site has an exclusion area as required by 10 CFR 100, located within the 12,300 acres owned by_ Houston Lighting & Power Company. The exclusion area l for the South Texas Project is oval shaped, encompassing both Units 1 and 2. j The minimuin distance from the center of the Unit 1 containment building to the i exclusion area boundary is 1430 m (4692 ft). There are no residents within the exclusion area. The applicant owns and controls all of the land and mineral
- i rights within tha exclusion area. Therefore, the applicant has the authority i required by 10 CFR 100 to determine all activities in this area. The only ac-tivities unrelated to Unit 1 operation that occur within the exclusion area in-clude activity associated with the maintenance and operation of the proposed high voltage direct current terminal, and the construction of Unit 2. There 1 are no railroads, highways, or waterways traversing the exclusion area. In 4 case of an emergency, arrangements have been made to limit access and control the activity and evacuation of anyone in the exclusion area.
i Second, beyond and surrounding the exclusion area is a low population zone (LPZ), also required by 10 CFR 100. The LPZ for.the South Texas Project is a circular j area with a 4828-m (15,480-ft) radius measured from a point 93 m west of the j center of the Unit 2 containment building. The area within the LPZ is sparsely populated and situated about 7.2 m (23 ft) above mean sea level. It is generally ' h South Texas DES 8 Appendix F
, _ . _ _ _ _ _ _ , . _ _ . _ . _ . - . . _ . . . _ _ . _ _ _ _ . , , _ ~ _ _ _ , . _ _ _ . . , _ . . _ . _ . _ _ . .
flat, consisting mostly of agricultural land, with some wooded areas and very little industrial development. Within this zone, the applicant must ensure ' that there is a reasonable probability that appropriate protective measures could be taken on behalf of the residents and other members of the public in the event of a serious accident. The applicant has indicated that there were about 149 persons residing in the LPZ in 1980, and projects the population to
- increase to about 468 by the year 2030. In case of a radiological emergency, the applicant has arranged to carry out protective actions, including evacuation l
of personnel in the vicinity of the South Texas nuclear plant. For further j details, s'ee the following section on emergency preparedness. Third, 10 CFR 100 also requires that the distance from the reactor to the nearest boundary of a densely populated area containing more than about 25,000 residents be at least one and one-third times the distance from the reactor to the outer boundary of the LPZ. Since accidents of greater potential hazards than those commonly postulated are conceivable, although highly improbable, it was consid- . ered desirable to add the population center distance requirements in 10 CFR 100 to provide for protection against excessive exposure doses to people in large centers. Bay City, Texas, located about 19 km (12 mi) north-northeast of the , plant with a projected population greater than 35,000 by 2030, is the popula- " tion center nearest to the site. The distance from the site to Bay City is at least one and one-third times the distance to the outer boundary of the LPZ. There are no major cities within 80 km (50 mi) of the site. Except for Lake Jackson City which is 68 km (42 mi) east-northeast of the site (1980 popu-lation of 19,102), Bay City is essentially the largest populated area in the vicinity of the plant (1980 population of 17,837 persons). The population density within 48 km (30 mi) of the site when the plant is scheduled to go into operation (1990) is projected to be 26 persons per mi2 (10 persons per km2 ), and is not expected to exceed 47 persons per mi2 (18 persons per km2 ) during the life of the plant. The safety evaluation of the South Texas Project has also included a review of potential external hazards, i.e., activities off site that might adversely affect the operation of the plant and cause an acci-dent. This review encompassed nearby industrial, transportation, and military facilities that might create explosive, missile, toxic gas or similar hazards. The risk to-the South Texas facility from such hazards has been found to be ! negligibly small. A more detailed discussion of the compliance with the Com-mission's siting criteria and the consideration of external hazards will be given in the staff's Safety Evaluation Report. (3) Emergency Preparedness , Emergency preparedness plans including protective action measures for the South Texas Project and its environs are under review and have not been fully
- completed. Before full power reactor operation, a finding will be required j
that the state of onsite and offsite emergency preparedness provides reasonable l assurance that adequate protective measures can and will be taken in the event i of a radiological emergency. Among the standards that must be met by these plans are provisions for two emergency planning zones (EPZs). A plume exposure pathway EPZ of about 16 km (10 mi) in radius and an ingestion exposure pathway l EPZ of about 80 km (50 mi) in radius are required. Other standards include appropriate ranges of protective actions for each of these zones, provisions i for dissemination to the public of basic emergency planning information, pro-L { visions for rapid notification of the public during a serious reactor emergency, I and methods, systems, and equipment for assessing and monitoring actual or po-tential offsite consequences in the EPZs of a radiological emergency condition. South Texas DES 9 Appendix F l l
. _ _ . . _ _ _ _ _- _ _ .-_.-. _ _ .~. _. ,__ _ _. ._ - _. _ - .
NRC and the Federal Emergency Management Agency (FEMA) have agreed that FEMA will make a finding and determination as to the adequacy of State.and local government emergency response plans. NRC will determine the adequacy of the applicant's Emergency Response Plans with respect to the standards listed in Section 50.47(b) of 10 CFR 50, the requirements of Appendix E to 10 CFR 50, and the guidance contained in NUREG-0654/ FEMA-REP-1, Revision 1, " Criteria for Prepa-ration and Evaluation of Radiological Emergency Response Plans and Preparedness in Support of Nuclear Power Plants," dated November 1980. After the above deter-minations by NRC and FEMA, the NRC will make a finding in the licensing process as to the overall and integrated state of preparedness. The NRC staff findings will be reported in a supplement to the SER. Although the presence of adequate and tested emergency plans cannot prevent an accident, it is the staff's judg-ment that such plan, when implemented, can mitigate the consequences to the public if an accident should occur. F. 5 Accident Risk and Impact Assessment (1) Design-Basis Accidents , , As a means of ensuring that certain features of South Texas Units 1 and 2 meet acceptable design and performance criteria, both the applicant and the staff have analyzed the potential consequences of a number of postulated accidents. Some of these could lead to significant releases of radioactive materials to the environment and calculations.have been performed to estimate the potential radiological consequences to persons offsite. For each postulated initiating event, the potential radiological consequences cover a considerable range of values depending upon the particular course taken by the accident and the co'n di-tions, including wind direction and weather, prevalent during the accident. Three categories of accidents have been considered based upon their probability of occurrence and include: (1) incidents of moderate frequency (events that can reasonably be expected to occur during any year of operation), (2) infre-quent accidents (events that might occur once during the lifetime of the plant), and (3) limiting faults (accidents not expected to occur but that have the potential for significant releases of radioactivity). The radiological conse-quences of incidents in the first category, also called anticipated operational occurrences, are similar to the consequences from normal operation that are discussed in Section 5.9.3 of the main body of this environmental statement. Some of the initiating events postulated in the second and third categories for the South Texas plants are shown in Table F.2. To evaluate the potential envi-ronmental impact inherent in the operation of the South Texas plant, the appli-cant has analyzed a variety of accidents, in a more realistic manner, using the guidance of Regulatory Guide 4.2, Revision 2, " Preparation of Environmental Reports for Nuclear Power Plants." The types of accidents presented in Table F.2 are similar to some events evaluated in the staff's Safety Evaluation Report. The applicant's estimates of the radiation doses to individuals at the exclusion area boundary for the plant during the first 2 hours are also shown in Table F.2. These results reflect the expectation that certain engineered safety features designed to mitigate the consequences of the postulated accidents would function as intended. An important assumption in these evaluations is that the releases considered are limited to noble gases and radioiodines and that other radio-active materials are not released in significant quantities. South Texas DES 10 Appendix F
l l The staff does not perform an independent assessment of the potential offsite consequences using realistic assumptions for such accidents. Instead, the staff estimates potential upper-bound exposures to individuals for the same types of l accidents contained in Table F.2 for the purpose of. implementing the provisions I of 10 CFR 50 and 10 CFR 100. For the staff evaluations, more pessimistic assump-l tions are made as to the course taken by the accident and the prevailing plant conditions;.the accidents are referred to as design-basis accidents. The assump-tions used for the design-basis accidents include much larger amounts of radio-i active material released, single failures o'f equipment, operation of ESFs in l a degraded mode
- and poor meteorological dispersion conditions. Although not l
discussed herein, the results of the staff's evaluation are described in detail in the Safety Evaluation Report (SER) for the South Texas Project. For comparison with the dose values in Table F.2, the results taken from the construction permit ~ stage SER show that the limiting whole-body exposures are > not expected to exceed 8 rem to an individual at the exclusion area boundary. They also show that radioiodine releases have the potential for offsite expo-sures ranging up to about 141 rem to the thyroid. For such an exposure to occur, an individual would have to be located at a point on the site boundary where the radioiodine concentration in the plume has its highest value and inhale at a breathing rate characteristic of an adult jogging for a period of
'2 hours. The health risk to an individual receiving such an exposure to the thyroid is the potential appearance of benign or malignant thyroid nodules in about 5 out of 100 cases, and the development of a fatal thyroid cancer in about 2 out of 1000 cases.
None of the calculations of the impacts of design-basis accidents described in this section takes into consideration possible reduction in individual or popu-lation exposure as a result of taking any protective actions. ; (2) Probabilistic Assessment of Severe Accidents In this and the following three sections, a discussion of the probabilities and consequences of accidents of greater severity than the design-basis acci-dents discussed in the previous section is provided. As a class, they are considered less likely to occur, but their consequences could be~ more severe, both for the plant itself and for the environment. These severe accidents, I sometimes called Class 9 accidents, can be distinguished from design-basis accidents in two primary respects: they involve substantial physical deterio-ration of the fuel in the reactor core (including overheating to the point of melting) and they involve deterioration of the capability of the containment structure to perform its intended function of limiting the release of radio-active materials to the environment. The assessment methodology employed is that described in the Reactor Safety Study (RSS), which was published in 1975 (WASH-1400, now designated NUREG-75/014). A less comprehensive but more up-to-date treatment is given in NUREG/CR-2300, "PRA Procedures Handbook." Because WASH-1400 has been subject to considerable controversy, a discussion of.the uncertainties surrounding it is provided in Section'F.5(8).
*The containment structure, however, is assumed to prevent leakage in excess of that which can be demonstrated by testing, as provided in 10 CFR 100.11(a).
i South Texas DES 11 Appendix F
l i,
- However the sets of accident sequences that were found in the RSS to be the dominant contributors to the risk in the prototype PWR (Westinghouse-designed Surry Unit 1) have been updated. The present as'sessment for the South-Texas Project has used accident sequences and release categories based on the recent
- (1985) Accident Source Term Program Office (ASTP0) research work on new source terms (Case 1) and on a 1980 understanding of fission product release (Case 2),
as described in Appendix G of this environmental statement. The two cases have been assessed to provide a perspective on risks that demonstrates the impact of a better understanding of fission product releases, chemistry, and attenuation under accident conditions. Characteristics of the. sequences (and release cate-gories) used (some of which involve complete melting' of the reactor core) are shown in Table F.3.
- l. Sequences initiated by external phenomena such as tornadoes, floods, or seismic events, and those that could be initiated by man, including deliberate acts of sabotage, are not included in the event sequences corresponding to the listed re-lease categories. The only plants for which external events have been assessed in detail by the staff in a prooabilistic sense are Zion Units 1 and 2, Indian Point Units 2 and 3, Limerick Units 1 and 2, and Millstone Unit 3. In these cases, no estimates.of risk from sabotage were made as these estimates are con-sidered beyond the state of the~ art. It is noted, however, that the consequences of large releases caused by sabotage should not be different in kind from the releases estimated for severe internally initiated accidents. For Zion and Limerick the licensees submitted probabilistic risk assessments which indicate external events can be significant contributors to risk. For Indian Point, staff evaluations also indicated significant risks from external events other
, than sabotage. By significant, the staff means that the best estimate of the ! additional risk from external events other than sabotage were calculated to be i as much as a factor of 30 higher compared to the best estimate risks from internal events at Indian Point, but about 2 to 10 times the best estimate risk from internal events at Zion.'
Although the staff made no numerical assessment of externally initiated accident risks for South Texas Project, the staff did draw upon information from the Zion, Limerick, Millstone 3, and Indian Point studies. That is, the staff con-cludes the actual risks from internal and external causes (exclusive of sabotage) could be higher than those presented here, but are unlikely to exceed those i
! determined from risk multipliers computed for Zion, Limerick, and Indian Point.
These multipliers would not result in risks at South Texas Project outside an uncertainty range of a factor of 100 times the risks from internal events as l discussed in Section F.5(8). The calculated probability per reactor year associated with each accident se-quence (or release category) used is shown in Table F.3. As in the RSS, there are substantial uncertainties in these probabilities. This is due, in part, to difficulties associated with the quantification of human error and to inade-quacies in the data base on failure rates of individual plant components that were used to calculate the probabilities. The magnitudes (curies) of radioactivity postulated to be released for each release category are obtained by multiplying the release fractions shown in 4 Table F.3 by the amounts that would be present in the core at the time of the j hypothetical accident. These are shown in Table F.1 for South' Texas Project i at a core thermal power level of 3800 MWt, the power level used in the safety i South Texas DES 12 Appendix F
--c------,- - - - _ _ . _ - _ - , . - _ - - - - _ _ - .
} evaluation. Of the hundreds of radionuclides present in the core, the 54 i listed in the table were selected as significant contributors to the health l and economic risks of severe accidents. The core radionuclides were selected t
- on the basis of (1) half-life, (2) approximate relative offsite dose contribu- !
tion, and-(3) health effects of the radionuclides and their daughter products. The potential radiological consequences of these releases have been calculated by an updated version of.the consequence model (NUREG/CR-2300), used in the RSS, adapted and modified as described below to apply to a specific site. The essential elements are shown~in schematic form in Figure F.2. Environmental parameters specific to the South Texas site have been used and include the
; following.
meteorological data for the site representing a full year of consecutive hourly measurements and seasonal variations ; j projected population. for tiac year 2010 extending to an 800-km (500-mi) radius from the plant. j - the habitable land fraction within an 800-km (500-mi) radius 1 - land-use statistics, on a statewide basis, including farm land values, farm product values including dairy production, and growing season infor-mation for the State of Texas and each surrounding state within the 800-km (500-mi) region (land-use statistics for Mexico were assumed to be the 4 same as for adjacent states) To obtain a probability distribution of consequences, the calculations are per-formed assuming the releases, as defined by the release categories, at each of 91 different " start" times throughout a 1 year period. Each calculation used (1) the site-specific hourly meteorological data, (2) the population project-i ions for the year 2010 out to a distance of 800 km (500 mi) around the South Texas site, and (3) seasonal information for the time period following each
" start" time. The consequence model also contains provisions for incorporating
- the consequence-reduction benefits of evacuation, relocation, and other pro-tective actions. Early evacuation and relocation of people would considerably
~
reduce the exposure from the radioactive cloud and the contaminated ground in the wake of the cloud passage from severe releases. The evacuation model used
! (see Appendix H of this environmental statement) has been revised from that in the RSS for better site-specific application. The quantitative characteristics of the evacuation model used for the South Texas site are estimates made by the staff. There normally would be some facilities near a plant, such as schools or hospitals, where special equipment or personnel may be required to effect evacuation, and some people near a site who may choose not to evacuate. There-fore, actual evacuation effectiveness could be greater or less than that charac- ;
terized, but it would not be expected to be very much less, because special consideration will be given in emergency planning for the South Texas Project j to any unique aspects of dealing with special facilities. The other protective actions include: (1) either complete denial of use, ) i limited use, or permitting use only at a sufficiently later time after appro-priate decontamination of foodstuffs such as crops and milk, (2) decontamina-tion of severely contaminated environment (land and property) when it is con-
' sidered to be economically feasible to lower the levels of contamination to protective action guide (PAG) levels, and (3) denial of use of severely con-I taminated land and property for varying periods of time until the contamination South Texas DES 13 Appendix F l i
i ) '
i I levels are reduced by radioactive decay and weathering to such values that property can~be economically decontaminated as in (2) above. These actions would reduce the radiological exposure to the people.from immediate and/or i subsequent use of or living in the contaminated environment. Early evacuation within and early.rclocation of people from outside the plume exposure pathway 4 zone and other protective actions as mentioned above are considered as essen-4
' tial sequels to serious nuclear reactor accidents involving significant release of radioactivity to the atmosphere. Therefore, the results shown for South Texas Project include some benefits of these protective actions. "
There are also uncertainties in each facet of the estimates of consequences and the error bounds may be as large as they are for the probabilities. l The results of the calculations using this consequence model are radiological , doses to individuals and to populations, health effects that might result from I these exposures, costs of implementing protective actions, and costs associated I with property damage by radioactive contamination.
; (3) Dose and Health Impacts of Atmospheric Releases The results of the atmospheric pathway calculations of dose and health impacts performed for the South Texas facility and site are presented in the form of probability distributions in Figures F.3 through F.7* and are included in the impact summary table, Table F.4. All of the release categories shown in Table F.3 contribute to the results, the consequences, each being weighted by its associated probability.
Figure F.3 shows the probability distribution for the number of persons who might-receive bone-marrow doses equal to or greater-than 200 rem, whole-body doses equal to or greater than 25 rem, and thyroid doses equal to or greater than 300 rem from early exposure,** all on a per reactor year basis. The 200-f I rem bone-marrow dose figure corresponds approximately to a threshold valve for which hospitalization would be indicated for the treatment of radiation injury.
- Figures F.3 through F.7 are called complementary cumulative distribution i
functions (CCDFs). They are intended to show the relationship between the i probability of a particular type of consequence being equalled or exceeded and the magnitude of the consequence. Probability per reactor year (r y) is the chance that a.given event will occur in one year for one reactor. Because the different accident releases, atmospheric dispersion conditions and changes of a health effect (for example, early fatalities) result in a wide range of calculated consequences, they are presented on a logarithmic plot in which numbers varying over ~a very large range can be conveniently illustrated by a grid indicated by powers of 10. For instance, 106 means one million or 1,000,000 (1 followed by 6 zeros). The cumulative probabili-ties of equalling or exceeding a given consequence are also calculated to *
; vary over a large range (because of the varying probabilities of accidents and atmospheric dispersion conditions), so the probabilities are also plotted logarithmically. For instance, 10 6 means one millionth or 0.000001. ,
**Early exposure to an individual includes external doses from the radioactive
!~ cloud and the contaminated ground, and the dose from internally deposited radionuclides from inhalation of contaminated air during cloud passage. Other pathways of exposure are excluded. South Texas DES 14 Appendix F
The 25-rem whoie-body dose and 300-rem thyroid dose figures correspond to the Commission's guideline values for reactor siting in 10 CFR 100. Figure F.3 shows in ti.e left-hand portion that chances are no more than approxi-mately 8 in a million (8 x 10 6) per reactor year that one or more persons may receive doses equal to or greater than any of the doses specified. The fact that the curves initially run almost parallel horizontally shows that if one person were to receive such doses, the chances are about the same that ten to hundreds'would be so exposed. The chances of larger numbers of persons being exposed at those levels are seen to be considerably smaller. For example, the chances are less than 1 in 10 billion (1 x 10 10) that 10,000 or more people might receive bone-marrow doses of 200 rem or greater. Virtually all of the exposures reflected in this figure would occur within a 32-km (20-mi) radius. Figure F.4 shows the probability distribution for the total population exposed in person-rem; that is, the probability per reactor year that the total popu-lation exposure will equal or exceed the values given. For perspective, popu-lation doses shown in Figure F.4 may be compared with the annual average dose to the population within 80 km of the South Texas site resulting from background radiation of 26,000 person-rem, and to the anticipated annual population dose to the general public (total U.S.) frem normal plant operation of 82 person-rem (excluding plant workers) (Appendix D, Tables D.7 and 0.8). Figure F.5 shows the probability distributions for early fatalities, repre-senting radiation injuries that would produce fatalities within about 1 year after exposure. All of the early fatalities would be expected to occur within a 24-km (15-mi) radius. The results of the calculations shown in this figure and in Table F.4 reflect the effect of evacuation within the 16-km (10-mi) plume exposure pathway zone. Figure F.6 represents the statistical relationship between population exposure and the induction of fatal cancers that might appear over a period of many years
- following exposure. The impacts on the total population and the population
- within 80 km are shown separately. Furthermore, the fatal latent cancers have been subdivided into those attributable to exposures of the thyroid and all other organs. These estimates may be compared to the cancer fatality risk per individual per year from all causes of 1.9 x 10 3 (American Cancer Society, 1981).
4 An additional potential pathway for doses resulting from atmospheric release is from fallout onto open bodies of water. This pathway has been investigated in
- the staff analysis of the Fermi Unit 2 plant, which is located on Lake Erie, and for which appreciable fractions of radionuclides in the plume could be deposited in the Great Lakes (NUREG-0769). It was found that for the Fermi site, the in-dicated individual and societal doses from this pathway were smaller than the
' interdicted doses from other pathways. Furthermore, the individual and societal liquid pathway doses could be substantially eliminated by the interdiction of the aquatic food pathway in a manner comparable to interdiction of the terres-trial food pathway in the present analysis. The staff has also considered fallout onto and runoff and leaching into water bodies in connection with a study of severe accidents at the Indian Point reactors in southeastern New York (Written staff testimony on Commission Question 1, Section III.0 by Richard Codell on Liquid Pathway Considerations for the Indian Point ASLB Special Hearing, June 1982-April 1983). In this study, empirical models were developed South Texas DES 15 Appendix F
based upon considerations of radionuclide data collected in the New York City water supply system as a result of fallout from atmospheric weapons tests. As with the Fermi study, the Indian Point evaluation indicated that the uninter-dicted risks from this pathway were fractions of the interdicted risks from other pathways. Furthermo're, if interdicted in a manner similar to interdiction assumed for other pathways, the liquid pathway risks from fallout would be a very small fraction of the risks from other pathways. Considaring the regional meteorology and hydrology for the South Texas site, there is nothing to indicate that the liquid pathway contribution to the total accident risk would be signi-ficantly greater than that found for Fermi 2 and Indian Point. (4) Economic and Societal Impacts As noted in Section F.2. the various measures for avoidance of adverse health effects, including those resulting from residual radioactive contamination in the environment, are possible consequential impacts of severe accidents. Cal-culations of the probabilities and magnitudes of such impacts for the South Texas Project and environs have also been made. Unlike the radiation exposure and health effect impacts discussed above, impacts associated with adverse health effects avoidance are more readily transformed into economic impacts. The results are shown as the probability distribution for costs of offsite mitigating actions in Figure F 7 and are included in Table F.4. The factors contributing to these estimated costs include the following: evacuation' costs value of milk contaminated and condemned cost of decontamination of property where practical indirect costs attributable to loss of use of property and income derived therefrom The last-named costs would derive from the necessity for interdiction to prevent the use of property until it is either free of contamination or can be economi-cally decontaminated.
~
Figure F.7 shows that at the extreme end of the accident spectrum these costs could exceed several billion dollars, but that the probability that this would occur is small (about one chance in a million per reactor year). Additional economic impacts that can be monetized by the RSS consequences model include costs of decontamination of the facility itself. Another impact is the cost of replacement power. Probability distributions for these impacts have not been calculated, but they are included in the discussion of risk considera-tions in Section F.5(6) below. (5) Possible Releases to Groundwater This section presents a comparative evaluation of the radiological consequences that might result following a large accidental release of radionuclides from the South Texas Project reactors to the local groundwater system. Such releases could occur following a postulated core meltdown with eventual penetration of j the containment building basemat. Molten core debris.would exit the melt nole into the ground below the water table. The soluble radionuclides in the debris could be leached and transported by groundwater to downgradient wells used for l South Texas DES 16 Appendix F I
l drinking water or to surface water bodies used for drinking water, aquatic food, and recreation. Releases of radioactivity to the groundwater underlying the site could also occur through the failed basemat by means of depressurization of the containment atmosphere or the release of radioactive water from the emer-j gency core cooling system. t An analysis of the potential consequences of a liquid pathway release of radio-
, activity was presented in the " Liquid Pathway Generic Study" (t PGS). The LPGS l 1 compared the risk of accidents involving the liquid pathway (drinking water, !
irrigation, aquatic food swimming, and shoreline usage) for five conventional, generic, land-based, nuclear plants and a floating nuclear plant (for which the
, nuclear reactor would be mounted on a barge and moored in a body of water). It is this generic report that provides the basis for a comparative evaluation of the South Texas units.
i In the LPGS, parameters for each generic land-based site were chosen to repre-sent averages for a wide range of real sites and were thus " typical," but did i not represent any actual plant sites'. , e l Doses to individuals and populations were calculated in the LPGS without taking credit for possible interdiction methods such as isolation of contaminated groundwater, the temporary restriction of fishing, or providing alternative sources of drinking water (or additional purification equipment). Such inter-diction methods would be highly successful in preventing exposure to'radioac-l tivity and the liquid pathway consequences would therefore be economic and social rather than radiological. The study concluded that the individual and population doses for the liquid pathway would be a small fraction of the air- !
; borne pathway dose which could result from a core-melt accident.
s The LPGS presented analyses for a four-loop Westinghouse PWR located at five !
; land-based sites, two of which are similar to the South Texas site. The South Texas reactors are also four-loop Westinghouse PWRs. Thus the source term i used for South Texas in this comparison was assumed to be equal to that used +
i in the LPGS. The South Texas site is underlain by the Beaumont Formation which extends to a depth of about 427 m (1400 ft) in the site vicinity. Although this formation
~
consists predominantly of clay ~ materials, it also contains silty sands, sandy silts, and some fine to medium sand layers which form the aquifer that supplies l'
- the groundwater in the area. These two zones are effectively separated by a confining impervious stiff clay layer about 46 m (150 ft) thick. >
4 The deep aquifer zone which lies below depths of 76 to 91 m (250 to 300 ft) in
- the site area provides water of acceptable quality for irrigation and for domes-l tic and most industrial uses. Piezometric levels in this aquifer, whicF is confined by the 46-m (150-ft)-thick clay layer, range between 15 and 24 m (50 !
and 80 ft) below the ground surface at the site. Recharge is by infiltration ! i ~ l 'of precipitation and stream percolation at higher e1evation, north of the plant 4 where the aquifer crops out. The recharge area begins 2.4 to 16.1 km (8 to 10 mi) i north of the plant and extends northward beyond the Matagorda County boundary. 1 i The shallow aquifer zone is 27 to 46 m (90 to'150 ft) decp in the site area. l This zone is further divided into lower and upper units which are also separated i by a silty clay layer about 4.6 m (15 ft) thick. Before construction of the
; South Texas DES 17 Appendix F L _ __ _ _ ___- _ _. _ .. _ -, _ _ _ _ _ _ _ _ _ _ _ _ _ _
plant, the piezometric levels in these two shallow units were somewhat different, I , being 1.5 to 2.4 m (5-to 8 ft) lower for the lower unit. Construction of the plant, however, has provided a hydraulic connection between the upper and lower units through the structural backfill, and thus it is expected that the piezo-metric level between the two aquifer units will stabilize in the vicinity of the plant. The applicant expects that during operation the shallow groundwater
-level will equalize at an elevation of about 5.5 m (18 ft) above mean sea level (MSL) datum [or some 3.0 m (10 ft) below grade).
The South Texas containment buildings are located at the base of the clay layer 1 that separates the upper and lower units of the shallow aquifer at an elevation i of -9.8 m (-32.0 ft) MSL. In the event of a core-melt accident, there could-be a. release of radioactivity to the lower shallow aquifer. This radioactivity would then be transported in the direction of groundwater flow. The South Texas facility has a large cooling reservoir located just south of the plant. This cooling reservoir is formed by an earth embankment which has been i constructed above ground on previous foundation soils. This impoundment of water creates a differential head between the operating level in the reservior and the groundwater level outside the reservoir. This differential head causes seepage to flow through the previous foundation soils beneath the embankment. , A portion of this seepage will be intercepted by some 700 relief wells located' along the perimeter of the reservoir embankment. The intercepted flow will be discharged as surface flow through a system of drainage ditches constructed at the downstream toe of the embankment. The unintercepted seepage flow will remain in the upper shallow aquifer and flow toward the southeast. The relief wells have designed to maintain the groundwater level at ~the toe of the embankment at an elevation of about 8.3~ m (27 f t) MSL. Since this level is higher than the expected stabilized groundwater level underneath the plant . 5.5 m (18 ft) MSL, a radioactive liquid spill would not be intercepted by the relief wells. The groundwater gradient in the shallow aquifer is toward the Colorado River. l Thus radionuclides entering the groundwater system beneath the plant would be , entrained in the groundwater flow to the Colorado River. Groundwater velocity was determined by use of Darcy's law which is as follows: v=S "e where: v = seepage velocity k = hydraulic conductivity i = hydraulic gradient n, = effective porosity or specific yield i The groundwater level at the plant site will be at an elevation of about 5.5 m (18 ft) ms1. The elevation of the Colorado River is about 0.61 m (2 ft) ms1. Therefore, the groundwater level drops about 4.9 m (16 ft) over the 4880-m (16,000-ft) distance from the plant to.the river. To be conservative, however, the staff assumed that the groundwater level at the plant would be at grade level elevation of 8.5 m (28 ft) MSL. This results in a drop of ~7.9 m (26 ft) between the plant and the river and gives a hydraulic gradient of 1.6 x 10 3 South Texas DES 18 Appendix F
The applicant provided hydraulic conductivity estimates of 2.0 x 10-2 cm/sec (20,700 ft/yr) to 3.1 x 10-2 cm/sec (32,000 ft/yr) from field pumping tests and an estimate of porosity of 0.37. This value of porosity is close to the upper limit quoted in textbooks for similar material. Therefore, it was accepted for use by the staff. The applicant did not provide an estimate of effective poro-sity, so the staff assumed a conservative textbook value of 0.20. Using the above parameters, the staff calculated a groundwater velocity of 78 m/yr (256 f t/yr). At this velocity, it would take about 62 years for groundwater to travel 4880 m (16,000 ft) from the plant to the Colorado River. The radionuclide source which would ultimately be transmitted through the groundwater to the Colorado River is dependent on the core radionuclide inven-tory, the fraction of the radionuclide inventory that is released to the ground-water, and the attenuation that takes place during transport through the ground-water, principally from. radioactive decay and adsorption. ~As stated above, the South Texas reactors are four-loop Westinghouse PWRs simi-lar to the PWR considered in the LPGS; therefore, the core radionuclide inventory assumed in the LPGS was used in the South Texas analysis. A number of release cases were considered in the LPGS; however, for South Texas only the case of a prompt release of highly contaminated sump water released through a failed base-mat was considered. This was the PWR-7 scenario in the LPGS. This release was chosen because, of those studied in the LPGS that could contribute to the groundwater pathway, this release would result in the highest population dose. In the LPGS case, 24% of the Sr-90 and 100% of the Cs-134 and Cs-137 isotopes in the core inventory were considered to be released to the ground in the sump water. Transport in the groundwater was relatively slow because of " retardation" caused by interaction of the radionuclide with the rock or soil, so decay of many radionuclides was appreciable. Of the activity released, only 87% of the Sr-90 and 31% of the Cs-137 were estimated to enter the river. Dose contribu-tions from radionuclides other than Sr-90 and Cs-137 were considered negligible. Thus it was demonstrated in the LPGS that for groundwater travel times on the-order of years, the only significant contributors to population dose are Sr-90 and Cs-137. The degree of retardation of radionuclides is governed by various physical properties such as bulk density, aquifer porosity, and equilibrium distribution coefficient. The relationship between groundwater velocity (or groundwater transport time), radionuclide ad:>rption, and the (decayed) radionuclide frac-tion, which ultimately enters the surface water, is given by the following expression: 0.693T R d Fr = exp (t 1/2 ) where: Fr = fraction of radio mclide that ultimately enters the river. T = groundwater transport time t 1/2
= radionuclide half-life R = retardation factor which is a measure of the velocity of ground-d water relative to the expected velocity of the radionuclide South Texas DES 19 Appendix F
l l i The retardation factor is equal to 1 + pKd where ( ) p = bulk density of the aquifer media n = porosity of the aquifer K = distribution coefficient which indicates the extent to which sorption d takes place for a particular ion. It is the ratio _of the mass of radionuclide adsorbed per gram of soil divided by the mass of radio-nuclide dissolved per millimeter of groundwater A typical value of the ratio p/n is 5.0; however, for consistency with the LPGS, a value of 4.1 was used here as well (a lower p/n results in a larger Fr and is thus conservative). Distribution coefficients are difficult to estimate; how-ever, Parsons (1962) estimated distribution coefficients (K s) dof 20 and 200 for Sr-90 and Cs-137, respectively, and Isherwood (Lawrence Livermore Laboratory, 1977) suggested that K d s for sand range from 1.7 to 43 for Sr and 22 to 314 for Cs. For the South Texas Project, the staff conservatively estimated nuclide travel time using the distribution coefficients used in the LPGS. These were 2 ml/g for Sr and 20 ml/g for Cs. This resulted in retardation factors of 9.2 for Sr-90 and 83 for Cs-137. Using these values, the travel time would be about 570 years for Sr-90 and 5140 years for Cs-137. When these times are compared with 5.7 years for Sr-90 and 51 years for Cs-137 in the LPGS case, the longer travel times at South Texas would allow a small portion of the radioactivity to enter the Colorado River. In the'LPGS, 87% of the Sr-90 and 31% of the Cs-137 entered the river. For South Texas, virtually all of the Sr-90 and Cs-137 would have decayed before reaching the river. The staff, therefore, concludes that the population dose for South Texas would be less than that for the LPGS case, and that the liquid pathway at South Texas does not pose an unusual contribution to risk when compared to other land-based sites. Thus the liquid pathway risk is small when compared with the risk posed by airborne pathways. Finally, there are measures that could be taken to further minimize the impact of the liquid pathway. As described above, the staff estimated that groundwater travel time from the reactor building to the Colorado River would be about 62 years and that the most significant nuclides would be retarded by sorption. This would allow ample time for engineering measures such as slurry walls and well point dewatering to isolate the radioactive contamination near the source and to establish a groundwater monitoring program that would ensure early detec-tion if any contaminants should escape the isolated area. A comprehensive dis-cussion of these and other mitigation methods potentially applicable to the South Texas Project is contained in two reports prepared by Argonne National Laboratory (May 1982, September 1982). (6) Risk Considerations The foregoing discussions have dealt with both the frequency (or likelihood of occurrence) of accidents and their impacts (or consequences). Because the ranges of both factors are quite broad, it is also useful to combine them to obtain average measures of environmental risk. Such averages provide a useful perspec-tive, and can be particularly instructive as an aid to the comparison of radio-logical risks associated with accident releases and with normal operational releases. South Texas DES 20 Appendix F
A common way in which this combination of factors is used to estimate risk is to multiply the probabilities by the consequences. The resultant risk is then expressed as a number of consequences expected per unit of time. Such a quan-tification of risk does not at all mean that there is universal agreement that attitudes about risks, or about what constitutes an acceptable risk, can or should be governed solely by such a measure. At best, it can be a contributing factor to a risk judgment, but not necessarily a decisive factor. Table F.5 shows average values of risk associated with population dose, early fatalities, latent fatalities, and costs for evacuation and other protective actions. These average values are obtained by summing the probabilities multi-plied by the consequences over the entire range of the distributions. Becaus~e the probabilities are on a per-reactor year basis, the averages shown are also on a per-reactor year basis. The population exposures and latent cancer fatality risks may be compared with those for normal operation :hown in Appendix D of this environmental statement. The comparison (excluding e>posure to the plant personnel) shows that the acci-dent dose risks (expressed an person-rem per reactor year) to the total popu-lation are about 3 times Nigher than the anticipated doses per year from normal operation, but the accident dose risks within 80 km (50 mi) are about 50 times higher than the anticipated normal operation doses within 80 km. The late.2 cancer fatality risks from potential accidents can be compared to the cancer risk from all other sources. For accidents, these risks averaged over those within 80 km (50 mi) of the South Texas plant, are 2.8 x 10 8 per
- year per person for Case 1 (1985 source terms) and 3.2 x 10 8 per person for Case 2 (1980 source terms), compared with the cancer fatality risk per individ-ual from all other sources of 1.9 x 10 3 per year.
There are no early fatality or economic risks associated with protective actions and decontamination for normal releases; therefore, these ri~sks are unique for accidents. For pers ityrisksof7x10gectiveandunderstandingofthemeaningoftheearlyfatal-(Case 2) and 5 x 10 '> (Case 1) per reactor year,' however, the staff notes that, to a good approximation, the population at risk is that within about 24 km (15 mi) of the plant, about 31,000 persons in the year 2010. Accidental fatalities per year for a population of this size, based upon over-all averages for the United States, are approximately 7 from motor vehicle acci-dents, 2.3 from falls, 1 from drowning, 1 from burns, and 0.4 from firearms. The average early fatality risk from reactor accidents is thus an extremely small fraction of the total risk embodied in the above combined accident modes. Figure F.8 shows the calculated risk expressed as whole-body dose to an individ-ual from early exposur.e as a function of the downwind distance from the plant within the plume exposures pathway zone. The values are on a per-reactor year basis and all accident sequences and release categories in Table F.5 contributed to the' dose, weighted by their associated probabilities. Evacuation and other protective actions can reduce the risk to an individual of early fatality or of latent cancer fatality. Figure F.9 shows lines of constant risk per reactor year of early fatality, to an individual living within the emergency planning zone of the South Texas site, as a function of location result-ing from potential accidents in the reactor. Figure F.10 shows similar curves of constant risk of latent cancer fatality. Directional variations in these South Texas DES 21 Appendix F
1 I 1 plots reflects the variation in the average fraction of the year the wind would be blowing in different directions from the plant. For comparison, the following risks of fatality per year to an individual living in the United States may be noted (National Research Council, 1979, p. 577): motor vehicle accident-- 2.2 x 10 4, falls--7.7 x 10 5, drowning--3.1 x 10 5, burns--2.9 x 10.s, and firearms 1.2 x 10 5 The economic risk associated with evacuation and other protective actions could be compared with property damage costs associated with alternative energy generation technologies. The use of fossil fuels--coal or oil, for . example--would cause substantial quantities of sulfur dioxide and nitrogen oxides to be emitted into the a'.mosphere and, among other things, lead to environmental and ecological damage through the phenomenon of acid rain (National Research Counci?, 1979, pp. 559-560). This effect has not, however, been sufficiently quantified for a useful comparison to be drawn at this time. (a) Other Economic Risks There are other risks that can be expressed in monetary terms, but are not in-cluded in the cost calculations discussed in the section on economic and socie-tal impacts. These impacts, which would result from an accident at the facil-ity, produce added costs to the public (i.e., ratepayers, taxpayers, and/or shareholders). These costs would accrue from decontamination and repair of the facility and from increased expenditures for replacement power while the unit is out of service. Experience with such costs is being accumulated as a result of the accident at the Three Mile Island facility. If an accident occurs during the first full year of commercial operation of
, the South Texas Project Unit 1 (beginning in 1987), the economic penalty to which the public would be exposed would be approximately $1850 million (1987 dollars) for decontamination and restoration, including replacement of the damaged nuclear fuel. This estimate is based on a conservative (high) 10%
annual escalation of the 1980 economic penalty determined for the Three Mile
, Island facility (Comptroller General,1981). Although insurance would cover
$500 million or more of the $1850 million accident cost, the insurance is not credited against this cost because the arithmetic product of the insurance payment and the risk probability would theoretically balance the insurance premium. ;
In addition, system fuel costs will increase by approximately $253 million (constant 1987 dollars) for replacement power during each year South Texas Pro-ject Unit 1 is out of service. This estimate assumes that the unit will oper-
. ate at an average 60% capacity factor and that replacement energy will be provided primarily from gas- and oil-fueled generation. If the unit does not operate for 8 years, replacement power costs could amount to $2024 million (constant 1987 dollars). Higher capacity factors would, of course, result in even greater replacement power costs.
The probability of a core melt or severe reactor damage is assumed to be as
- high as 10 4 per reactor year (this accident probability is intended to account for all severe core-damage accidents leading to large economic consequences for the owner and not just leading to significant offsite consequences). Multiply-ing the sum of the previously estimated repair and replacement power costs of approximately $3874 million for an accident to a unit during the initial year of its operation by the above 10 4 probability, results in an economic risk of South Texas DES 22 Appendix F
approximately $387,400 during the first full year (1987 dollars, or for the purpose of comparison with other costs presented in this.section, $199,000 in 1980 dollars). This is also the approximate economic risk (in constant 1987 dollars) to South Texas Project Unit 1 during each subsequent year of operation, although this amount will gradually decrease as the nuclear unit depreciates in value and operates at a reduced annual capacity factor. The annual economic risk to South Texas Project Unit 2 is similarly $387,400 (constant 1987 dollars).
, (b) Regional Industrial Impacts A severe accident that requires the interdiction and/or decontamination of land areas will force numerous businesses to temporarily or permanently close. These closures would have additional economic effects beyond the contaminated areas through the disruption of regional markets and sources of supplies. This sec-tion provides estimates of these impacts that were made using: (1) the accident 4
consequence model previously discussed and (2) the Regional Input-Output Modeling System (RIMS II) developed by the Bureau of Economic Analysis (BEA) (NUREG/CR-2591). Regional industrial impacts were estimated for both the 1980 rebaselined PWR i accident release categories and the 1985 source term release categories. The industrial impact model developed by BEA takes into account contamination
. levels of a physically affected area defined by the accident consequence model.
l Contamination levels define an interdicted area immediately surrounding the j plant,' followed by an area of decontamination, an area of crop interdiction, i and finally an area of milk interdiction.
! Assumptions used in the analysis include the following:
c (1) In the interdicted area, all industries would lose total production for more than a year. (2) In the decontamination zone, there would be a 3-month loss in nonag-ricultural output; a 1 year loss in all crop output, except there l would be no loss in greenhouse, nursery, and forestry output; a 3-month loss in dairy output; and a 6-month loss in livestock and poultry output.
! In the crop interdicted area, there would be no loss in nonagricul-t (3) _tural output; a 'l year loss in agricultural output, except there l would be no loss in greenhouse, nursery, and forestry output; no loss
- in livestock and poultry output; and a 2-month loss in dairy output.
(4) In the milk interdicated zone, there would be only a 2-month' loss in dairy output. The estimates of industrial impacts are made for an economic study area that consists of a physically affected area and a physically unaffected area. An 2 accident that causes an adverse impact in the physically affected area (for ex-ample, the loss of agricultural output) could also adversely affect output in
~
1 the physically unaffected area (for example, food processing). In addition to the direct impacts in the physically affected area, the following additional impacts would occur in the physically unaffected area: 4 South Texas DES 23 Appendix F l
,-,- ,- <-a -w - , - - ,,m,.-,----,w_ n-- , , - - - >-g-g wg,---- ,--r_mm-s--,---.--n- - - - .-y,, --mm-.- m. .--nwn 4 m--mmn
(1) decreased demand (in the physically affected area) for output pro-duced in the physically unaffected area (2) decreased availability of production inputs purchased from the j physically affected area Only the impacts occurring during the first year following an accident are con-sidered. The longer term consequences are not considered because they will vary widely depending on the level and nature of efforts to mitigate the accident consequences and to decontaminate the physically affected areas. The estimates assume no compensating effects such as the use of unused capacity in the physi-cally affected area, or income payments to individuals displaced from their jobs that would enable them.to maintain their spending habits. These compensating effects, which would reduce the industrial impacts, would occur over a lengthy period. The estimates using no compensating effects are the best measures of first year economic impacts. Table F.6 presents the regional economic output and employment impacts and cor-responding expected risks associated with various release categories (for addi-tional information regarding the release categories, see Appendix G of this environmental statement). The estimated overall risk value using output losses as the measure of accident consequences, expressed in a per-reactor year basis, is $2903 using the 1980 accident release sequences and $490 using the 1985 source term release sequences. These totals are composed of direct impacts of $1844 (1980) and $83 (1985) in the nonagricultural sector, and $748 (1980) and $358 (1985) in the agricultural sector, and indirect impacts of $311 (1980) and $49 (1985) from decreased export and supply constraints. For both sets of se-quences, corresponding expected employment loss per reactor year is less than 0.2 job. It should be noted that regional economic impacts estimated using the 1985 acci-dent release sequences are considerably lower than those derived from the 1980 sequences. Also, while losses are greater for nonagriculture using the 1980 sequences, agricultural losses are greater than nonagricultural losses using the 1985 sequences. The staff has also considered the health care cost resulting from hypothetical-accidents in a generic model developed by the Pacific North-west Laboratory (1983). On the basis of this generic model, the staff concludes that such costs may be a fraction of the offsite costs evaluated herein, but that the model is not sufficiently constituted for application to a specific reactor site. (7) Conditional Mean Values of Accident Consequences The conditional mean values of potential societal consequences of several kinds from each release category in Table F.3 are shown in Table F.7. These means were calculated by the CRAC2 code and represent averages of each kind of conse-quence for each release category over the spectrum of meterological conditions at the South Texas site. " Conditional" mean values are so called because these mean values are conditional upon the occurrence of the accidents represented by the release ~ categories. Probabilities of re! ease categories have not been fac-tored into these mean value estimates. The conditional mean values are provided for a perspective only; they are devoid of much importance without simultaneous association of probabilities of the release categories to which the mean values are due. They are useful, however, in judging the relative importance of dif-ferent sequences. South Texas DES 24 Appendix F
4 Table F.7 is useful for risk calculations. It can be used to calculate the risk of any particular kind of consequence (sho.wn in the table) from any of the
. listed release categories by simply multiplying the conditional mean value of the given consequence by the probability per reactor year (Table F.3) of the release category to which the mean value is due. It can also be used to cal-culate the risk of any particular kind of consequence from a group of release categories by calculating the sum of the products of the conditional mean values
. of the consequence and the proh bilities of the respective release categories in the group; the group may inclade some or all of the release categories.
.(8) Uncertainties
- The probabilistic risk assessment discussed above has been based mostly upon the methodology presented in the Reactor Safety Study (RSS) which was published in 1975 (NUREG-75/014). Although substantial improvements have been made in various facets of the RSS methodolcgy after its publication, there are still large uncertainties in the results of the analysis presented in the preceding sections, including uncertainties associated with the likelihoods of the acci-dent sequences ard containment failure modes leading to the release categories,
, the source terms for the release categories, and the estimates of environmental consequences. The relatively more important contributors to uncertainties in the results presented in this environmental statement are as follows:
(a) Probability of Occurrence of Accident I j If the probabilty of a release category would change by a certain factor, th'e probabilities ~ of various types of consequences from that release category would also change exactly by the same factor. Thus, an order of magnitude uncer- ' l tainty in the probability of-a release category would result in a corresponding - j order of magnitude uncertainty in both societal and individual risks stemming
! from the release category. As in the RSS, there are substantial uncertainties i
in the probabilities of the release categories. This is due, in part, to dif-ficulties associated with the quantification of the human error and to inade-
~
i quacies in the data-base on failure rates of individual plant components, and
, in the data base on external events and their effects on plant systems compo-nents that are.used to calculate the probabilities.
i-Another related area of uncertainty are risks from externally caused accidents (such_a3 earthquakes, floods, and man-caused events including sabotage). No i evaluations of such risks have been made for the South Texas plant. Some of these types of risks have been evaluated for the Indian Point Units 2 and 3 reactor in New York State, the Millstone Unit 3 reactor in Connecticut, the two Limerick reactors in Pennsylvania, and for the two Zion reactors in Illinois. }- These risks were found within a factor of less than 100 times greater than risks from internally initiated accidents at the corresponding plants. Such experiences in plant-specific probabilistic risk assessments cannot be ex-l tended directly to the South Texas plant.because of site and plant design charac-
! teristics. The staff does, however, judge the risks to be characterized by the uncertainty buunds discussed below.
j' (b) Quantity and Chemical Form of Radioactivity Released This relates to the quantity and chemical form of each radionuclide species that
; would be released from a reactor unit during a particular accident sequence.
South Texas DES 25 Appendix F
4 4 Such releases would originate'in the fuel, and would be attenuated by physical and chemical processes'en route to being released to the environment. Depending on the accident sequence, attenuation in the reactor' vessel, the primary cooling system, the containment, and adjacent buildings would influence both the magni-tude and chemical form'of radioactive releases. The source terms used in the staff ~ analysis were determined from the recent (1985) Accident Source Term Pro-
' ? gram Office research work on'new source terms (Case 1) and from a 1980 under-standing of fission product release (Case 2). Information available in NUREG-0956 and from the latest research activities sponsored by the Commission and the industry. indicate that best estimate s'ource terms (Case 1) are, for the most part, substantially lower than the source; term used for the 1980 under-standing of fission product release (Case 2) for the same types of initiating accident sequences. The impact of smaller source terms would be lower estimates of healtn effects, particularly early fatalities and injuries.
(c) Atmospheric Dispersion Modiling for t'he Radioactive Plume Transport, Including the Physical anu Chemical 8ehavior of Radionuclides in Particulate Form in the Atmosphe e Uncertaintics are involved in teodeling the atmospheric transport of radioac-tivity in gaseous and particulate states, and the actual transport, diffusion, and deposition or fallout that wou?d cccur during an accident (including the effects of condensation and precipitation)' The phenomenon of plume rise from 4 heat associated with the atmospheric release, effects of precipitation on the plume, and fallout of particu ate matter from the plume all have considerable impact on the magnitudes of early health consequences, and the distances from the reactor where these consequences would occur. The staff judges that these factors s can result in substantial overestimates or underestimates of both early 1 and later effects (health and economic). Other areas that have substantial but relatively less effect on uncertainty than the preceding items are: (i) duration and energy release, warning time, and in plant radionuclide decay time: These areas relate to.the differences between assumed release duration, energy
.of release, and the warning and'in plant radioactivity decay times compared with those that would actually occur during a real accident.
9 For a relatively long duration (greater than a half-hour) of an atmospheric re-N lease, the actual cross-wind spread (i.e., the width) of the radioactive plume Q would likely be larger than the width calculated by the dispersion model in the staff code (CRAC). However, the effective width of the plume is calculated in
.the code using a plume expansion factor that is determined by the release dura-tion. For a given quantity of radionuclides in a release, the plume and, there-fore, the area that would come under its' cover would become wider if the release
' duration were made longer. In effect, this'would result in lower air and ground concentrations of radioactivity, but a greater area of contamination.
The thermal energy associated with the release affects the plume rise phenome-non which results in relatively lower air and ground concentrations in the closer-in regions, and relatively higher'cw. centration because of fallout in the farttergout regions. Therefore, if large thermal energy were associated with South Texas DES 26 Appendix F u .
l 1 l l a release containing a large fraction of core-inventory of radionuclides, it could increase the distance from the reactor over which early health effects may occur. If, on the other hand, the release behavior were dominated by the presence of large amounts of condensing steam, very much the reverse could oc-cur because of close-in deposition of radionuclides induced by the falling water condensed from the steam. Warning time before evacuation has considerable impact on the effectiveness of offsite emergency response. Longer warning times would improve the effective-ness of the response. The time from. reactor shutdown until the beginning of the release to the. environment (atmosphere), known as the time of release, is used to calculate t.he depletion of radionuclides by radioactive decay within the plant before release. The depletion factor for each radionuclide (determined by the radio-active decay constant and the time of release) multiplied by the release frac-tion of the radionuclide and its core inventory determines the actual quantity of the radionuclide released to the environment. Later releases would result in the release of fewer curies to the environment for given values of release fractions. The first three of the above parameters can have significant impacts on acci-dent consequences, particularly early consequences. The staff judges that the early consequences and risks calculated for this review could be substan-tial underestimates or overestimates, because of uncertainties in the first three parameters. (ii) meteorological sampling scheme used: There is a possibility that the meteorological sequences used with the selected 91 start times (sampling) in the CRAC code may not adequately represent all meteorological variations during the year, or that the year of meteorological data may not represent all possible conditions. This factor is judged to pro-duce greater uncertainties for early effects and less for latent effects. (iii) emergency' response effectiveness: This relates to the differences between modeling assumptions regarding the emergency response of the people residing near the South Texas site compared to what.would happen during an actual severe reactor accident. Included in these considerations are suca subjects as evacuation effectiveness under dif-ferent circumstances, possible sheltering and its effectiveness, and the ef-fectiveness of population relocation. The staff judges that the uncertainties associated with emergency response effectiveness could cause large uncertainties in early health consequences. The uncertainties in latent health consequences and costs are considered smaller than those for early health consequences. (iv) dose conversion factors and dose response relationships for early health consequences, including benefits of medical treatment: There are uncertainties associated with the conversion of contamination levels to doses, relationships of doses to health effects, and considerations of the availability of what was described in the RSS as supportive medical treatment (a specialized medical treatment program of limited availability that would South Texas DES 27 Appendix F
. minimize the early health effect consequences of high levels of radiation expo-sure following a severe reactor accident). Previous staff analysis indicates that uncertainty for this last source is less than a factor of three. Although all health impacts have not been enumerated therein, the primary-ones have been, y and references to other documents such as the RSS provide additional insights into the subject. (v) dose-conversion-factors and dose response relationships for latent health consequences: Estimates of dose and latent (delayed and long-term) health' ef fects on individ-uals and on their succeeding generations-involve uncertainties associated with conversion of-contamination. levels to doses and of doses to health effects. The staff judges .that this category has a large uncertainty. The uncertainty could result in relatively small underestimates of consequences, but also in substan-tial overestimates of consequences. (Note: radiobiological evidence on this subject does not preclude zero health consequences.)
- (vi) chronic exposure pathways, including environmental decontamination and the fate-of deposited radionuclides
Uncertainty arises from the possibility of different protective action guide levels that may actually be used for interdiction or decontamination of the ex-posure pathways from those assumed in the staff analysis. Furthermore, uncer-tainty arises because people lack precise knowledge about the fate of the radio-nuclides in the environment as' influenced by natural processes such as runoff and weathering. The staff's qualitative judgment is that the uncertainty from l these considerations is substantial. 7
- (vii) economic data and modeling
This relates to uncertainties in the economic parameters and economic modeling, such as costs of evacuation, relocation, medical treatment, cost of decontamin-ation of properties, and other costs of property damage. Uncertainty in this ' area could be substantial. ; The state of the art for quantitative evaluation of'the uncertainties in the i probabilistic risk analysis such as the type presented here is not well devel-
-oped. Therefore, although the staff has made a reasonable analysis of the
~
risks presented herein consistent with current data and methodology, there are large uncertainties associated with'the results shown. It is the qualitative judgment of the staff that the uncertainty bounds could be well over a factor of 10, but not as large as a factor of 100. Within these uncertainty bounds, however,.the uncertainties associated with the probability-integrated values
- consequences (i.e., the risks) are likely to be less (although still'large) than uncertainties in the curves in the figures showing probability distribu-tion of consequences, because of partial cancellation of uncertainties by integration.
The accident at~Three Mile Island occurred in March 1979 at a time when the ac-cumulated experience record was about 400 reactor years. It is of interest to
- ' note that this implied accident frequency was within the range of frequencies estimated by the RSS for an accident of this severity (National Research Council, 1979, p.-553). It shoul'd also be noted that the Three Mile Island accident has South Texas DES 28 Appendix F e - --,,4, - , ,-- - = - - . , . - - - , , - , . . - . . ----------.e-- - - - - - - - , - - - . . . - , . . - . ~ . - , - - - - - . - - - - - ~ , . - - - - -
U resulted in a.very comprehensive evaluation of reactor. accidents by a significant number of investigative groups. Actions to improve the safety of nuclear power plants have resulted from these investigations, including those from the Presi-dent's Commission on the Accident at Three Mile Island, and NRC staff investiga-tions and task forces. A comprehensive !'NRC Action Plan Developed as a Result of the TMI-2 Accident" (NUREG-0660, Vol. I), collects the various recommendations- '
~of these groups and describes them under the subject areas of: Operational Safety; Siting and Design; Emergency Preparedness and Radiation Effects; Prac-4 tices and Procedures; and NRC Policy, Organization and Management. The action plan presents a sequence of actions, some already taken, that results in a grad-ually increasing improvement in safety as individual actions are completed. The South Texas units will receive the benefit of these actions.
- (9) Comparison of South Texas Plant Risks With Other Plants
.To provide a perspective on how the South Texas plant compares in terms of risks from severe accidents with some of the other nuclear power plants that are either operating or that are being reviewed by the staff for possible issuance 1
of a license to operate, the estimated risks from severe accidents for several nuclear power plants (including those for South Texas Units 1 and 2) are shown
! in Figures F.11 through F.19 for three important categories of risk. The values i for individual plants are based upon three types of estimates: from the RSS ,
(labeled WASH-1400 Average Plant), from independent staff reviews of contempor-ary probabilistic risk assessments (Indian Point 2 and 3, Zion, Limerick, and i Millstone 3), and from generic applications of RSS methodology to reactor sites for environmental statements by the staff (for 27 nuclear power plants). i Figure F.11 indicates that the calculated risk of early fatality at the South l Texas site is much lower than the median of the plants evaluated. Figures F.12
! and F.13 show that the calculated risk of latent cancer fatalities are lower
} than the median of the plants evaluated. Figures F.14 through F.19 show the - l range of estimated uncertainties for the three measures of risk. F.6 Conclusions The foregoing sections consider the potential environmental impacts from acci-dents at the South Texas plants. These have covered a broad spectrum of possi-ble accidental releases of radioactive materials into the environment by atmos-t pheric and groundwater pathways. Included in the considerations are postulated l design-basis accidents and more-severe accident sequences that might lead to i core melting. The environmental impacts that have been considered include po-l tential releases of radioactivity to the environment with resulting radiation d exposures to individuals and to the population as a whole, the risks of near-and long-term adverse health effects that such exposures could entail, and the < potential economic and societal consequences of accidental contamination of the
; environment.
[' The environmental consequences were also assessed using both 1980 and 1985 levels of understanding of the release and attenuation of fission products in accidents.
- The consequences estimated from the 1985 understanding are lower than estimations from the use of 1980 informationc .The impacts could be severe, but the likeli-i hood of their occurrence is judged to be small. This conclusion is based on j (1) the fact that considerable experience has been gained with the operation of i similar facilities without significant degradation of the environment, (2) the fact that in order to obtain a license to operate the South Texas facility, the South Texas DES 29 Appendix F 4
-.--,.~_..,_,,.--,,-m,. , , , . _ . _ . . , , _ , - . ~ _ _ , . . _-.m..,_m... , , - , _ , . _ _ _ _ , - _ - , - - - , _ , , , _..m _, . - _ _
I 1 i-t- applicant-must comply with the applicable Commission regulations and requirements, and (3) a probabilistic assessment of the risk based upon the methodology devel-oped in the Reactor Safety Study. l This review has not revealed the potential for any new accident sequences that i have:not been previously identified for other Westinghouse PWRs with large dry containments. A comparison of the other NRC-reviewed PWR risk studies for plants of.similar design to South Texas Units 1 and 2 indicates that the varia-tion-is rather small and,'therefore, accident risk estimates for the South
- Texas plants are expected to be comparable and probably even lower than the other plants reviewed.
1 , On the basis of the above considerations, the staff concluded that there are no special or unique circumstances about the South Texas site and environs that would warrant consideration of alternatives for South Texas Units 1 and 2. i e J l 3 1 f i i 1 i l South Texas DES 30 Appendix F
F.7 -Bibliography American Cancer Society, " Cancer Facts and Figures," 1981. , Argonne National Laboratory, " Accident Mitigation: ' Methods for Isolating
-. Contaminated Groundwater," September 1982.
-- , " Accident Mitigation: Slurry Wall Barriers," May 1982.
Battelle Columbus Laboratory, Report BMI-2104, "Radionuclide. Release Under
- Specific LWR Accident Conditions," July 1984.
Brookhaven National . Laboratory, Technical Report A-3804, " Estimates of Steam Spike and Pressurization Loads for a Subatmospheric Containment," July 1985 l (in preparation). Comptroller General of the U.S., EMD-81-106, " Report to the Congress," Office
, of the Comptroller General, A~ugust 26, 1981.' . Houston Lighting & Power Company. " South Texas Units 1 & 2, Final Safety j Analysis Report," July 1978.~ ;
i Land, ~C. E. , " Estimating Cancer Risks From Low Doses of Ionizing Radiation,'.' l Science, 209, 1197, 12. September 1980. l Lawrence Livermore Laboratory, " Preliminary Report on Retardation Factors and
; Radionuclide Migration, August 1977.
Meyer, J. F., and W. T. Pratt, direct testimony concerning Commission
, Question 1, Indian Point Hearings, Docket Numbers 50-247 and 50-286, 1983.
Millstone Point Co., " Millstone-3 Final Safety Analysis Report," May 1984. National-Academy of Sciences / National Research Council, Advisory Committee on the Biological Effects.of Ionizing Radiations (BEIR I), "The Effects on Population of Exposure to Low Levels of Ionizing Radiation," November 1972. - -- , BEIR III, "The Effects on Population of Exposure to Low Levels of Ionizing i Radiation: 1980," July 1980. i . National'Reasearch Council, Committee on Nuclear Alternative Energy Systems (CONAES), " Energy in Transition 1985-2010," Final Report, 1979. i
- Oak Ridge National Laboratory, Nuclear Safety Information Center, " Description ;
L of Selected Accidents That Have Occurred at Nuclear Reactor Facilities,"
- April 1980.
Pacific Northwest Laboratory, Report PNL-4664, " Estimating the Economic Costs i of Radiation-Induced Health Effects," November 1983. I Parsons, P. , " Underground Movement of Radioactive Wastes at Chalk River," in i Proc 2nd Conference on Groundwater Disposal of Radioactive Wastes, Chalk River, Canada, J. Morgan, D. Jamison, and J. Stevenson, Eds., Atomic Energy j Commission (Canada), TID-7628, 1962. South Texas. DES 31 Appendix F
Power Authority of New York, " Indian Point Unit 3, Final Safety Analysis Report," December 1970. President's Commission on the Accident at Three Mile Island, Final Report, October 1979. Thompson, T. J., and J. G. Beckerley, The Technology of Nuclear Reactor Safety, Vol. 1, The MIT Press, Cambridge, Massachusttts, 1964. United Kingdom National Radiological Protection Board, "An Assessment of the Radiological Impact of the Windscale Reactor Fire," October 1957. U.S. Nuclear Regulatory Commission, Memorandum from W. C. Lyon to B. W. Sheron,
" Observations From Trip to the South Texas Project in Regard to Severe Accidents," August 5, 1985. -- , " Nuclear Power Plant Accident Considerations Under the National Environ-mental Policy Act of 1969," Statement of Interim Policy, 45 FR 40101-40104, June 13, 1980. -- , NUREG-75/014, " Reactor Safety Study--An Assessment," October 1975. -- , NUREG-0340, " Overview of the Reactor Safety Study Consequences Model,"
October 1977.
-- , NUREG-0440, " Liquid Pathway Generic Study," February 1978. -- , NUREG-0558, " Population Dose and Health Impact of the Accident at the Three Mile Island Nuclear Station," May 1979. -- , NUREG-0651, " Evaluation of Steam Generator Tube Rupture Accidents,"
March 1980.
-- , NUREG-0654, (Rev. 1), " Criteria for Preparation and Evaluation of Radiological Emergency Response Plans and Preparedness in Support of Nuclear Power Plants," November 1980. -- , NUREG-0660 (Vol.1), "NRC Action Plan Developed as a Result of the THI-2 Accident," May 1980. -- , NUREG-0737, " Clarification of TMI Action Plan Requirements," November 1980. -- , NUREG-0769, " Final Environmental Statement Related to the Operation of Enrico Fermi Atomic Power Plant, Unit No. 2," March 1982. -- , NUREG-0773, "The Development of Severe Reactor Accident Source Terms:
1957-1981," November 1982.
-- , NUREG-0850 (Vol.1), " Preliminary Assessment of Core Melt Accidents at the Zion and Indian Point Nuclear Power Plants and Strategies for Mitigating Their Effects," November 1981. -- , NUREG-0956, " Reassessment of the Technical Bases for Estimating Source Terms," Draf t Report for Comment, July 1985.
South Texas DES 32 Appendix F
-- ,.NUREG/CR-0400, " Risk Assessment Review Group Report to the U.S. Nuclear Regulatory Commission," September 1978. -- , NUREG/CR-1250, "Three Mile Island--A Report to the Commissioners and the Public," Vol.1, January 1980. -- , NUREG/CR-1596, "The Consequences From Liquid Pathways After a Reactor Meltdown Accident," June 1981. -- , NUREG/CR-2300, "PRA Procedures Guide," January, 1983. -- , NUREG/CR-2591, " Estimating the Potential Industrial Impacts of a Nuclear Reactor Accident: Methodology and Case Studies," April 1982. -- , NUREG/CR-3300 (Vol. 2), " Review and Evaluation of the Zion Probabilistic Safety Study: Containment and Site Consequence Analysis," July 1983. -- , NUREG/CR-4143, " Review and Evaluation of the Millstone Unit 3 Probabilistic Safety Study: Containment Failure Modes, Radiological Source-Terms and Off-Site Consequences," July 1985. -- ,' NUREG/CR-4197, " Safety Goal Sensitivity Studies," 1985. -- , WASH-1400, See NUREG-75/014.
Virginia Electric & Power Co., "Surry Units 1 & 2 Final Safety Analysis Report," December 1969. 33 Appendix F South Texas DES
i GASEOUS EFFLUENT NUCLEAR POWER PLANT E x- EF U T 4, t a:. r! git \ 9
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A N 4 Figure F.1 Radiation pathways to man South Texas DES 34 Appendix F
WE ATHER D ATA i i CELE ASE CATEGORIES- ATMOSPHERIC " D'SPERSf0N
~
% HEALTH EFFECTS CLOUD DEPLETION 4
, PROPERTY DAM AGE
, POPULATION _
r
~
OROUND " CONTAMINATION i EVACUATION Figure F.2 Schematic outline of consequence model i South Texas DES 35 Appendix F
_. - . . _ . _ . _ _ _ _ . . . . . _ _ _ . _ . _ _ _ __ _ _ . _ _.___ ._ r_.__. . . _ . ._ 4 i Distribution of Individual Doso impacts-i E c (1 of 2) E 16 18 i ~ 10' 16 18 16 1d 1d 8 10-*10 z. _ u .i_ u.u u _ _ _ t .. . o o .
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$ X = Individual Dose Impacts .
Figure F.3a Probability distribution of individual dose impacts [see Section F.5(7) !
for a discussion of uncertainties in risk estimates] ;
L r I } i
Distribution of Individual Dcse impacts T (2 o'f 2) , b 10' 16 10' 16 18 10' 18 18 ' 10'10 10-
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; p Figure F.3b Probability distribe, tion of individual cose impacts [see Section F.5(7)
{ , for a discussion of ungertainties in risk estimates] i l i
Distribution cf Early Fataliths C 10' 16 18 18 16 18 16 18 y 10d....n..
. . ....n . ...... ......n . ....n. . ... n. . . . . . . ......t -
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.t: -
Note: This figure is based on 1980 source terms; [
~6 - the 1985 results showed no early fatalities -
i 2
'o La.
. for the probabilities shown. -
' *mo 10-' : 10-' ta _ - g : :
, x - -
b 10 10 '
\
, u : : l a : : x -
. 5
* ~
! .O
- .8 10-' = -
10 f ! e- :
\__ 5 -
. m 10'" ' ' ' ' " " ' ' ' ' " " ' ' ' ' " " ' ' ' ' " " 10'" i 18 10' 18 10' - 16 16 16 16 1d
$e X = Early Fatalities i E.
;;- Figure F.4 _ Probability distributions of population exposures [see Section F.5(7)
, for a discussion of uncertainties in risk estimates] [50 mi = 60 km) 1 i
i
= - - - -
- Distribution of Population Exposures C
S-
;;* 10' 10' 16 10' 10' 18 16 1d 1d' E 10 g . ..... . . . .. . . . . . . . . . . . . . . . i i i i i i i . . . . . . . i . . . i . i; 10-'
g _ , w - 10-' = a 10-' , x 3 _g :
^ [
i E 10-5 N- ~~ " " ' ' ' N
- N -
10
-5 fc i
5 \,D 5 x : 0u 10 '
=
',N
',' = 10-'
e
=
. '\ :
=
- a. - '
1 g 10-' , a 10-' w x 3
'4.s s =
- I : r. :
b CL 10 ' = i *; e 10 *
= -
4, 3O 10 * =
=
8 :-
=
10-' a - s o - - Entire pop - 1980 source d i 10-in 10-io I Within 50 mi. - 1980 source .
. i
- ~~
- 3 Entfre ho6- 198h souree---- _.
E
- Within
""'" 5 mi.
' ''p~~ ~ ~' ~- ' 19
"" '@5
~ ~s
"'o
" ' "u' 'rce 10-i, 10 ,, ' ' ' ' ' ' ' ' ' ' ' ' " ' '
I
& 10' 10' 10' 10' 10' 10' 10' 1d* 1d' i X = Total Person-rem Whole Body h Figure F.5 Probability distributions of early fatalities with supportive medical treatment
[see Section F.5(7) for a discussion of uncertainties in risk estimates] 1
d
'e Distribution of fotolities - 50 miles C
9 (1 of 2) 5'
- 1d 16 18 10' 18 18 18 1d 10-*18 r ....on . ... ". .. .u" i'""> > >"" ' ' ' ' " " ' ' ' ' " " ' ' ' ' " " 10-'
. o N E
~
X A 10-, fN jg5 s _ i
=. g 5
~
g **4 \
= - .:, s -
5
-- 10-e s
' ?'. , s
= 10
o :
- =
! u : . c.,h', : ! e -
.s E 10-' .' 6 i s 10 o = -
o : i : a o I. ~
>- 10-' -
= Y.. t 2 16s i .
u 5 'a 1 u - c - e - c \ - o i. x 1o-' 1
= ; ;
=
10-'
= : .
3 : H - o - 1 S 1 0-'" Excl. thyroid - 1980 source - 10- 3 ct Thyr _ojd_ook_- _1980 sgurce
;_Exc_l. th roid - 19_83_sou_rc_e___
\ E T'h.yrpi,,pp.ly.. ,.]9,8,p..spyr,ce,,, , ,,,n, , ,,,n, , ,,,nm ,,,,nn ,,,,""
10'" 10-"
> 10' 10' 16 16 10' .
16 18 18 18 Em X = Latent Ccacer Fatalities b
' Figure F.6a Probability distributions of cancer fatalities [see Section F.5(7) for
} a discussion of uncertainties.in risk estimates] i i
T y Distribution of Fatalities - entire pop. 9 (2 of 2) i - 10 1d 18 18 10' 18 18 16
. . o n, 1d10 "
....n ..no ..on. . .i.on ,
10 ' -
....no . ...nn . ...nu i .
3 - I x _ A - '--
- 10-'
10-' [ j ] g ' -' , . , 35 - o - N . 10-* N 10-* - N b 5 .', - o - :s - c -
. s, -
0 -
.'.s O
-7
.'. = 10-7
. _ 10 ; .
E
~ 0 5 .'.s
.s -
x _ i .,. - u - 5 10-' \ - 10-* a
=
= s, \ =
x : . g -
.o -
10-' i Exci. thyroid - 1980 source 10"
\ !
ct _ Jhy_ro_id_g g!g _ _1_9_80,sg_u_rc_e_ _ . -
- Excl. th_yroid - 19_85 source _. .
Th ' "" ' "" ' "" ' "" ' "" 10-,. 10-,o "'"'"yroid '"" gnty"""198p"
- "" source 10' 16 16 10' 18 1d 10' 18 !'
i 10* X = Latent Concer Fatalities a a T
, Figure F.6b Probability distributions of cancer fatalities [see Section F.5(7) for a discussion of uncertainties in risk estimate] l l
8' Distribution of Mitigation Measures Cost C 9 K' 10' 18 10' 10' -18 18 10' 1d' i 5 10-'10' ,,,,m , , , , , , , , , , , ,,,,, ,,,t,,, , , , , , , , , , , , , , , , , , , , , , , , , , , , ,,,,3 10-o E E 4 m, v
#' 10-*
10-* - 5 A' - 5
-w,, -
x - 3 ', 1 10-* =
= ~ 10-'
m 3 , 'N : o - ' : o - r 10-' 1
> 10-' =
5 i : , s L - . g i- - N -
\
E. 10-* s ,h s
= 10-*
. x : 5
= : '. -
3 - ', : 4
.8 10-* = '
10-' o u
=
. e
- 1 : :
10 ' s-
=
=
10 i
- 21980 source term -
10-u
-- 1985
" ' ""'"soifree term "
10-"
# 10' 10' 10' 10' 10' 10* 10' 10' 1d' ] X = Total Cost in 1980 Dollars x
Figure F.7 Probability d'stribution of mitigation measures cost [see Section F.5(7) for a discussion af uncertainties in risk estimates]
19 C 9 Risk of Dose vs. Distance tO i x i 3 2.0 4.0 6.0 8.0 10.0 l c, 10-* 0.0 _ .10-* G : 1980 source term -
. . _19_ _8_5_ _s_o_u_r_c_e_ _t_e_r_m_ _ ._
y -
% s, N '
10"
- i. TO.s ;
's :
g o .
'N' .
\ \ e . r w - N o " . . O *, g g .
~~
O '~~. S a ~~.. - 10' TO :
.c __._--
5 ~ 10-' 10-* 0.0 2.0 4.0 6.0 8.0 10.0
, Distance in miles B
E e X
, Figure F.8 Individual risk of dose as function of distance [see Section F5(7) for a discussion of uncertainties in risk estimates] [to convert mi to km, multiply by 1.6093]
/ /
/ ~
/a g I l
\g
@e. %w-ht eay s. citys ....'.'.' ,'ifD7 .....
j ~- s:'o..e. _- 4..~"",,.- i 3 > /7 1 E el 1 i ! i Midfield r.,gfor"",.,aar w #'*? f,e) aj ef t g /
/y. ['
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.} ,
{ iElmaton [ g p ;3,i E.V . i i ,. ,4. . : s\e ,. w : f > y e s - ., v . y ;/, / i t-r;.) WNW"b id e [K [.g,c,,,)c;~t.Ql?i -j
- 7. s / 3 N,' O - ,
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\ //'l I -
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q 09 ,/' ,SW \ k-,ammiumese - Maranorda 9 [e, g if I 9 o j 10 mi / 7 f'CratlLagf G,
; -x y'*pi SE g gggggg3 gy j'
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~
MAT AGORDA B AY % PENINSUL A
~j o-'
s* ,~
/ , _ __ ! [ t
[M[ hcalIe h % 1 /
'/ ,. / -e
,u 4
a--name 1980 source term s v- .-
,#'! c0 1985 source term
.~\'
C+ $. g ,
]
r Q' / (,n g-
.,,r }
Figure F.9 Isopleths of risk of latent fatality per reactor year to an ! individual [to convert mi to km, multiply by 1.6093) South Texas DES 44 Appendix F
/- .
\ ;,/
8;
- q. 3
/ >
\
. ,- +
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+
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blessing * *
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w~ nk lfl Cptr p p "! l........i.. ai 9,y\i.L vysg.. - s g n.e. / w . u se,,j. o.;. ,- i 4 l Collek. ,. g Jg I fb;
- :.: 4 g\ - A/$ ff( /
j
< /
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f' . '~- s . ]' I [ h?'GQf 10sW
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, 1
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. /
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' S I ,/
f ,
) ,, =f. a { t . ! . i m i
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g', -" " N s V
/? r L ,, k ,
- ll w\ j -f ,
y r
} ,i (l l [,l M a l A fi U H ills I' t Id !"' ' UI I
/-f , [,' j .
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+
(,- G,h, ' / , u .! sf / . ,,, s ,- . i
#$ <ll f' fvlii r!"
j - w C! ' 8'8 mmB - 1980 source term l ,. k . gtj.\ t ' O3 1985 source term
, s' O
Ap i . i 4
; Figure F.10 Isopleths of risk of early fatality pei .2 actor year to an individual [to convert mi to km, multiply by 1.6093]
South Texas DES 45 Appendix f j 1
, . . . . - , , . - . - - - - - - . - . - , - - - . - . - - _- _.-n-- - - - - - - - - - - - .. . - - - - , - - -
10 : - LEGEND: I
~
_ a Plant-specific PRA e RSS methodology, NUREG4713 -
-{ Average of surrogate plants -
10-2 __
~
_= 2 m m - 10-3 :- E : * * -
$ ,- m *a g e . , -
g . b - W E d * [= 10 5 = .
- 5
$ -+ .- = . .
r 1a' -- * -
~
I
~
~ ~
- O -
10~8 r --
- e 2 2
~ ~
- Note: The South Tense Plant estimate le beoed on 1980 source ~
terme (Case 2h The 1985 resulte showed no eerfy fatality
, for the probabHatles shown. .
ig 7 I I I II I III I I I I I I II I I I I I I I I I I I I I ll. * * *
- jl.l1111lll1ll . 11
=
et se Q llllalilldilliidl!!ill!d,l!il Figure F.11 Estimated early fatality risk (persons) with supportive medical treatment from severe reactor accidents for several nuclear power plants either operating or receiving consideration for issuance of license to operate [see footnotes following figure F.19] South Texas DES 46 Appendix F
EpOg a. -l5b8T.t S F o i g j 1 1 1 1 1 u g 0 0 '.", 0 0 t u s
' 4 2 4 0 h r T
e _ _ _ : ::- - - - - ~=- .
. ~ :E -
=T - - - _ - ~_
e F ~ x . I 1 . . a s D 1 2 h'**lI q j- l I I i i 4 e E oosE _ ! I e S ppes eevt rrei
] '} - !
I l I e e* aarm 2 l I ttea ~ ei nre t ' l I I s a. ged =iI " 1 [ a 1 I e socl
- I .
erta e ot rre . I fe n ocat 1 I
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tner egno 3g I
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ufni l i= I . v Sa N eSn Dt : l rout r ercy f I
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oh t e f o i c 1srs . I }8 a I
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cwp I . u ol r r og R o P
- eee . ja I
- ga.y A rr . t
- o fp o s .il I e N U ln . c , 'lm I . pl R las a in) " n EG
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p n r . I . 7
- seo .
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F r _ _ _ I : =- _ _ - E- _ _ _ :E - - .
-_ : =- - - - ~
lll
S F EgOyag=$gowgwg o i 1 1 1 u t g u 0 4 0 4 w w 0 4 1
.0 1
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. - ~ ::= - :E - - - - :-r - - ~ ~0_
e F. j -l Ei ' x
= +
a 1 l5iI j ' s 3 D {h~ 1 I . 1 s E tefE e S oirs _{ l-~ ,1 1 a tot 1 e ohmi A 1 e p e m ersa 1 8 m, r et aove =iI " 8
' m tp e d eer 1 e rel ] I= '
e a a [trt . '
- siee enan .I '
egct t , fooc aJ ' _ orra $2 ' e o n _ trac nece ' , occr tei 2] ' , eidf 4 svea .1~ ' e 8 int fnta .1 air ' ogsl l i lcft =1 ' , oooy wnr ,5 3 ' , is nisi r '
. + euLEG gdes evk ,i ! $ ' . ARPE Fre iar( ,
v Sa N e SnD l i! ' r gtap a t : uil e e g m s-ro r .r ' e ep e enns 3 21}:
- ohc t
uo I f o i _ Ffcn s d if
. ols I . u o c 1re) r l 9 a, .. j~ ' e r og R oP
]ir s e Ai ' . ga, y A spx t uoc .u9Nm '
- e N awl ,
p U neu ,sj " ' . a ER l crd n A e i t G p pn .i l ' e s - p o lg 0 e fa I~ ' . T 1 n nt 3 d lth i, ' i isy - - x c e r o - - - : == __ _~:_- _-_ = = - _ _- 7 - - _ - : _= - - 2 C= F n i s e ,d l! l ; 'I
lo - E ..a n -n -- d d d Ob ab o n -
- r :
~ -
10~3 .. g g : o e : o o g - o _ o -- ti o m $ 104 =- , ,
' ' d '
=~
5 -- o 5
- a. -
o m - - o o g - o o g "' o to-a -- o o -
- .. -- o -
J- -- in 4 .- ._
- o ..
-- C o o o o -
o , , 10 4 ' ' ' ' ' ' ' ' ' ' ' ' ' I I I I I ll* ll* l b 5 ie s
"E 2
I" 5 j t
. j I ll 3 j
] ] . .t f f 5 1 a333.1.1sl_5>r$,a2433iIu5is . .
j j l h n n - Note: This figure is based on 1980 source term for South Texas; the 1985 results showed no early fatalities for the probabilities shown. Figure F.14 Estimated early fatality risk (persons) with supportive medical treatment from severe reactor accidents for several nuclear power plants either operating or receiving consideration for issuance of license to operate. Bars are drawn to illustrate effect of uncer-tainty range discussed in text [see footnotes following Figure F.19] South Texas DES 49 Appendix F
. . ~ . _ . - . _- _ - . -. _.. _ _ _ - -__--__ _ - .___._~ . . -
1.0 d i d i
=
~ ~
l I 10 - l
- . 2 .. ,, _--
C um 4 .
.im.
4 > t > 10 2 _ E : i '
, , , , I h 2 ~
e - o o o - E - 1 0 <> , , , ,t l i
$ - d ' t '
o o E 10'3 E 3
< >2 i '
t i
~
t , g - oi - 4 0 - 2 - g 4 d " io :- --
- ~
1 1 t i l 1 O
~
, ,~ ~ ~
~
4 10 _ = =2 1: Ceee 1 (19eMI - 4
, 2: Case 2 (1980)
I ' i l 33 4 I I i i I i i I i i i I it i 1 iI I l I I I I I a I IUll } } l J l e, } ll Figure F.15 Estimated latent thyroid cancer fatality risk (persons) from severe reactor accidents for several nuclear power plants either operating or receiving consideration for issuance of license to operate. Bars are drawn to illustrate effect of uncertainty range discussed in text [see footnotes following Figure F.19]
- l l South Texas DES 50 Appendix F
10 - _
~- -
.. .=
= ..
l 1.0 ;; :: 2 -- = em .. . 17 C" ""= l s :
~
$ [ < i n - -
I e - <> _ O " b <, 5 o a 10 2 7 j j2 , , ,, __ E ~ 1 i < i <> 1 '
=
- 4 i < > < i C o o g o g -
k 10-3 l-" . = l
.. 2 t
== -
4 2 -- 10 7 :: 3
.=
= .. ..
=
~ *
-- ==
~
- 1: Case 1 (1951 2: Cese 2 (1990) ,
3,.s, I I i iI I I I i e I I i iit iI i I I I I I I l ] e 2 o i y s
} l} I hh :
Figure F.16 Estimated latent thyroid cancer fatality risk (persons) from severe i reactor accidents for several nuclear power plants either operating
; or receiving consideration for issuance of license to operate, j Bars are drawn to illustrate effect of uncertainty range discussed in text [see footnotes following Figure F.19]
South Texas DES 51 Appendix F i I
e , 4 10 _
.. =
~
10 4 :- - l : .. E
~
, , [
10 4
=- _
- e : , , =
4 g - o o g - o _- a - o o - G o - E 4 10 =- - a = = g - < >
~
m - t 5 m a - . E ~' 8 - 10 .. -
~_ .
Sg 4 .. .. l ! f f
.,,7 I I P 1 I 11 lj l} lj ij l
1 I i l 1 A } i i ! Figure F.17 Estimated early fatality risk with supportive medical treatment I (persons) from severe reactor accidents for nuclear power plants I having plant specific PRAs, showing estimated range of uncertain-ties (see footnotes following Figure F.19] South Texas DES 52 Appendix F
I l 10
- =
- _ _ l
- 1.o =- ,. -= -
_ .. =_ o d o - . io - o - m : o % ,
~
$ 2 4 , -
g - g _ j 5 o a iga - w : :
- a. .
m - g _ t w 2 =- _
=
d -- - to .. l 3p i l 1 1 1 I ,, I ,, il I<, 11 l I i - 1 1 1 l l 8 Figure F.18 Estimated latent cancer fatality risk, excluding thyroid (persons) from severe reactor accidents for nuclear power plants having plant-specific PRAs, showing estimated range of uncertainties [see footnotes following Figure F.19] 1 South lexas DES 53 Appendix F
i. A. 1.0 n,,
= ,, ;
, ' \ ': .. -
\-
10 r ' 7 , I : _. o , k ? _ o - d > ( > 4 :- 10 oo :
=
,a _ =_
, _ o -
g - - c - o - o g _ _ E 108 =- '
=
m :: : E
~
y _
= _ _
t 10' =- --
=
_= _=
~~
4 10 =- -- 3,4 1 1 1 1 1 11 11 ll. l1 11 I 1 3 .1 2 } } Figure F.19 Estimated latent thyroid cancer fatality risk (persons) from severe reactor accidents for nuclear power plants having plant-specific PRAs, showing estimated range of uncertainties [see footnotes following this figure] South Texas DES 54 Appendix F
- ~ - - .- - .. .-
'l Notes for Figures F.11 through F.19 See Section F.5(7) for discussion of uncertainties. l Except for Indian Point, Zion, Limerick, Braidwood, Hope Creek, NMP2, and WNP-3, risk analyses for other plants in these figures are based on WASH-1400 (NUREG-75/014) generic source terms and probabilities for severe accidents and do not include external event analyses. For South Texas Units 1 and 2, the dominant accident sequence probabilities were assumed to remain at the RSS values, but the containment response characteristics and the radiological source terms were based upon the methodology of NUREG-0956. The staff and the applicants extensively reviewed Indian Point 2 and 3, Zion, Limerick and Mill-stone 3, including externally initiated accidents. The staff briefly reviewed Braidwood, Hope Creek, NNR,'and WNP-3 to determine plant-specific release cate-gory probabilities considering internal events only. On the basis of these reviews, the staff concludes that any or all of the values could be underesti-mates or overestimates of the true risks.
a Excluding severe earthquakes and turricanes. ii With evacuation within 10 mi (16 km) and relocation from 10-25 mi (16-40 km). i i South Texas DES 55 Appendix F
. _ . . .-.m _ _ __ _- ., - .- - - - -
Table F.1 Activity of radionuclides in each South Texas Unit 1 or 2 reactor core at 3800 MWt Radioactive inventory 1 Group /radionuclide in millions of curies Half-life (days) A. N0BLE GASES Krypton-85 0.66 3,950 Krypton-85m 29 0.183 Krypton-87 55 0.0528 Krypton-88 81 0.117 Xenon-133- 201 5.28 ! Xenon-135 41 0.384 B. 10 DINES
-Iodine-131 101 8.05 Iodine-132 138 0.0958 Iodine-133 201 0.875 Iodine-134 223 0.0366 Iodine-135 181 0.280 C. ALKALI METALS Rubidium-86 0.032 18.7 Cesium-134 8.9 750 Cesium-136 3.6 13.0 Cesium-137 5.5 11,000 D. TELLURIUM-ANTIMONY Tellurium-127 7. 0 0.391 Tellurium-127m 1. 2 109 Tellurium-129 37 0.048 Tellurium-129m 6.3 34.0 Tellurium-131m 14.9 1.25 Tellurium-132 138 3.25 Antimony-127 7.3 3.88 Antimony-129 40 0.179 E. ALKALINE EARTHS Strontium-89 107 52.1 Strontium-90 4.4 11,030 Strontium-91 127 0.403
- Barium-140 192 12.8 F. COBALT AND NOBLE METALS Cobalt-58 0.93 71.0 Cobalt-60 0.34 1,920 Molybdenum-99 192 2.8 Technetium-99m 170 0.25 Ruthenium-103 127 39.5 ,
Ruthenium-105 85 0.185 Ruthenium-106 30 366 Rhodium-105 59 1.50 i South Texas DES 56 Appendix F 1
Table F.1 (Continued) Radioactive inventory Group /radionuclide in millions of curies Half-life (days) G. RARE EARTHS, REFRACTORY OXIDES AND TRANSURANICS Yttrium-90 4.5 2.67 Yttrium-91 138 59.0 Zirconium-95 181 65.2 Zirconium-97 181 0.71 Niobium-95 181 35.0 Lanthanum-140 192 1.67 Cerium-141 181 32.3 Cerium-143 149 1.38 Cerium-144 101 284 Praseodynium-143 149 13.7 Neodymium-147 71 11.1. Neptunium-239 1914 2.35 Plutonium-238 0.067 32,500 Plutonium-239 0.025 8.9 x 106 Plutonium-240 0.025 2.4 x 106 Plutonium-241 4.0 5,350 Americium-241 0.0021 1.5 x 105 Curium-242 0.59 163 Curium-244 0.03 6,630 South Texas DES 57 Appendix F
Table F.2 Approximate 2-hour radiation doses from
-design-basis accidents at exclusion area boundary
- using realistic assumptions Dose (rem) at 1430 meters **
Design-basis accident Thyroid Whole body Infrequent accident: Steam generator tube <0.0001 0.0027 rupture *** 4 Fuel-handling accident 0.0091 0.0007. Limiting faults: Control rod ejection 0.24 0.0021 Large-break LOCA 2.4 0.022
- Values taken from the applicant's. operating license environmental report Table 7.1-12.
f ** Plant exclusion area boundary distance.
***See NUREG-0651 for descriptions of three steam generator.
tube rupture accidents that have occurred in the United States. 4 l South-Texas DES' 58 Appendix F l l l
m o Table F.3a Summary of atmospheric releases in hypothetical accident sequences: 1985 source term (Case 1)
$ Probabil-g ity per Time of b Release C Warningd Release Energy of Fraction of core inventory released x reacgor release duration time elevation release f
g 81n year (hr) (hr) (hr) (m) (108 8tu/hr) Xe-Kr l' Cs-Rb Te-Sb 8a-Sr Ru La9 rn 1 4.1x10 s 2. 5 10 0.5 10 2 1.0 7.5x10 2 5.6108 5.5x10 8 1.0x10 8 1.3x10.s 2,7,10 4 M 2 2.4x10 7 1.5 1 0.5 10 2 1.0 7.5x10 8 5.8x10 8 4.2x10 8 5.1x10 8 1.3x10 8 1.4x10 5 3 3.1x10 7 2.5 3 0.5 10 11 1. 0 5.1x10 3 1.1x10
- 1.1x10 8 3.2x10 8 1.1x10 8 9.4x10
- 4 3.1x10 7 2.5 1 0.5 10 0.7 1.0 5.0x10 3 ,:, g,go. s 2.5x10
- 6.8x10 4 2.6x10
- 1.3x10 8 5 2.7x10 7 12 10 2 10 2 1.0 3.9x10 1 3.8x10 8 2.0x10 1 8.6x10 2 1.2x10 2 1.7x10 4' 6 6.6x10.s 2 10 0 10 2 1.0~ 2.7x10 8 1.3x10 8 1.2x10 8 6.2x10 8 1.6x10.s 2.6x10 4 7 6.8x10.s 1 10 0 10 0 1. 0 5.3x10 8 2.tix10
- 1.8x10 4 1.8x10
- 2.7x10.s 5.8x10 7 8 2.7x10 8 8 1 6 10 0.7 1. 0 - 5.0x10 8 <1.10 8 1.5x10 s 1.2x10.s 4.3x10
- 2.1x10
- 9 6.6x10 8 12 1 10 10 1.1 1. 0 7.8x10 s 3,9,19.* 8.5x10 8 1.8x10 8 3.3x10.s 8.1x10 5 10 7.5x10 7 2. 5 10 0.5 10 0.2 1. 0 6.9x10 3 1.1x10.a 1.3x10 8 5.8x10 8 1.7110
- 2.4x10 6 11 3x10 8 1 2 0.8 0 3.4 1.0 8.4x10 8 7.3x10 8 2.5x10 2 2.2x10 8 4.5x10 8 1.1x10 8 12 1x10.a 1 2 0.8 0 3.4 1. 0 4.1x10 1 4.0x10 8 1.2x10 1 1.3x10 1 2.7x10 8 6.4x10 8 13 3x10 7 24 1 22 0 0 1. 0 0 0 0 0 0 0 14 8.5x10.s 24 1 22 10 0 3x10 8 1.5x10 4 0 0 0 0 0 15 2x10.s . . ,
.h h h h h h h
, "Unsmoothed values are used. ,
e b Time interval between start of hypothetical accident (shutdown) and release of radioactive material to the atmosphere.
' Total time during which the major portion of the radioactive material is released to the atmosphere.
d Time interval between recognition of impending release (decision to initiate public protective measures) and the release of radioactive mate' rial to the atmosphere.
' Organic fodine is combined with elemental iodhes in the calculations. Any error is negligible since the release fraction is relatively small for all large release categories.
#I ncludes Ru, Rh, Co, Mo, and Tc.
9 Includes Y, La, Zr, Mb, Ce, Pr, Nd, Np, Pu, Am, and Ca. h Wgligible Note: Source terms are described in detail in Appendix G of this environmental statement. t3 T.S fD CL Er n
m . ._ , _ _ m Tabla F.3b Summary of (tmospheric relacs:s in hypottatical accident sIquencts- 1980 sourco t:rs (Cts 2 2)' S-y Probabil-Fraction of core inventory released ity per d g Accident reacgor Time b DurationC- Warning d Energy f x sequence year (hr) (hr). (hr) (108 8tu/hr) Xe-Kr l' Cs-Rb Te-Sb Ba-Sr Ru La9 i su PWR-1 1x10 7 2.5 0.5 1.0 20 & 520 0.9 0.7 0.4 0.4 - 0.05 0.4 3x10.s' m V 1x10 7 2. 0 3.0 1. 0 : 1 1.0 0.64 0.82 0.41 0.1 0.04 0.0006
- TNL8'8 3x10.s 4.5 0.5 1.0 170 1. 0 0.31 0.39 0.14 0.04 0.02 0.002 PWR-2 Negligible 2. 5. 0.5 1.0 170 0.9 0.7 0. 5 0.3 0.06 0.02 4x10 8 PWR-3 3x10 7 5.0 1.5 2.0 6 0.8 0.2 0.2 0.3 0.02 0.01 3x10.s 52C-8 2x10.e 31.0 3.0 1.5 1 1.0 0.05 0.33 0.19 0. t,4 0.02 0.003 l PWR-4 Negligible 2.0 3.0 *2.0 1- 0. 6 0.09 .0.04 0.01 5x10 8 3x10.s 4,10.e PWR-5 5x10- 2.0 4.0 1.0 0.1~ 0.3 0.03 9x10 8 5x10 8- 1x10 8 6x10 4 - 7x10 5 PWR-6 6x10 7 12.0 10.0 1. 0 n/a 0.3 8x10 4 8x10 4 1x10 8 9x10 5 - 7x10.s 1x10.s PWR-7 3x10 5 10.0 10.0 1.0. n/a 6x10 8 2x10 5 1x10 5 2x10.s 1x10.s 1x10 8 2x10 7 PWR-8 4x10 5 0.5 0.5 n/a n/a 2x10 8 1x10
- 5x10 4 1x10.e 1x10.s 0 0 PWR-9 4x10 4 0.5 0.5 n/a n/a 3x10.s 1x10 7 6x10 7 1x10 8 1x10 88 0 0 l
'Unsmoothed values are used.
b Time interval between start of hypothetical accident (shutdown) and release of radioactive material to the atmosphere. ! C Total time during which the major portion of the radioactive material is released to the atmosphere. d Time interval between recognition of impending release (decision to initiate public protective measures) and the release of radioactive material. g to the atmosphere.
' Organic iodine is combined with elemental fodines in the calculations. Any error is negligible since the release fraction is relatively small for all.large release categories.
#1 ncludes Ru, Rh, Co, No, and Tc.
9 Includes Y, La, Zr, Nb, Ce, Pr, Nd, Np, Pu, Am, and Ca. ! . Note: Source terms are described in detail in' Appendix G of this environmental statement. i i t 4 i V (D C1 s-i t
e 5-
- r Table F.4a Summary of~ environmental impacts and probabilities: 1985 source term (Case 1)
E Population ' Fatal Persons Persons exposure in latent Cost.of offsite Probability exposed exposed millions of cancers mitigating of. impact.per to over .to over Early person-rem' (80.km/ actions (millions reactor year 200 rem 25 rem fatalities (80 km/ total) total) of 1980 dollars) 1x10 4 0 0 0 0/0 0/0 0 1x10 5 0 0 0 2/3 100/120 2 5x10 8 0 190 0 5/10 280/490 13 1x10 8 0 1,900 0 10/49 630/2500 190 1x10 7 70 16,500 0 19/160 1400/7300 1500 1x10 8 480 45,000 0 39/290 2100/17000 5700 Related figure F.3 F.3 F. 5 F.4 F. 6 F.7 E i a ir n
.T ' Table F.4b Summary of. environmental impacts and probabilities: 1980' source term (Case'2)
E
=r a Population Fatal @ Persons Persons exposure Latent Cost of offsite $ Probability ' exposed exposed millions of cancers mitigating .
a of impact per to over to over Early . person-rem,. 80 km/ actions (millions G reactor year 200 rem 25 rem fatalities 80 km/ total total of 1980 dollars) 1x10 4 0 0 0 0,006/0.007. 0/0 0.0 1x10 5 0' 0 0 0.9/0.2 60/100 1. 5 5x10 8 0 0 0 2/3 70/200 17.0 i 1x10 8 0 2,600 0 4/68 290/3,500 650 1x10 7 170 18,000 0- 17/190 960/7,600 3,800 g 1x10 8 2,100 140,000 18 28/280- 2,000/12,000 7,600 Related figure F. 3 F. 3 F.5 F. 4 F.6 F.7 E a G-n l
Table F.5 Average values of environmental risks due to accident per reactor year Average value 1- 1980 1985 Environmental risk (Case 2) (Case 1)- Population exposure: Person-rem within 80 km 38 59
- Total ~ person-rem 250 200 Early fatalities 7x10 7 5x10 9 :
Latent cancer fatalities: , All organs excluding-thyroid 0.01 0.009 Thyroid only 0.0008 0.0004
- Cost of protective actions
- and decontamination 2600 980
*1980 dollars.
1 4 't i 4 South Texas DES 63 Appendix F
cn o c
~
Er Table F.6a Regional economic impacts en output and employment: 1980 source term
--4
() Direct losses n,
- Loss in employ- Expected loss Accident Wind Nonagri- Agricul- Indirect Total ment, annualized in output per cs Loss sequence direction cultural -tural losses losses number of jobs reactor year rn
'O Maximum V NNE 9,322* 280* 1,178* 10,780* 418t 11" l
S2 C-6 NNE 402* 124* 64* 590* 29t 1* PWR-6 All 0* 0* 0* 0* Of 0* Minimum V ESE 2* 0* 0* 2* Ot 0* S2C-6 ESE 0* 0* 0* 0* Of 0* PWR-6 All 0* 0* 0* 0* Ot 0* Risk /r y V- All 53** 17** 8** 78** <1tt - 52C-6 All 6** 9'* 2** 17+* <199 . PWR-6 All 0** 0** 0** 0** Ott - Total risk /r y All All 1,844** 748** 311** 2,903** <0.2tt -
- Millions of 1983 dollars.
an **1980 dollars. tThousands of jobs. ftNumber of jobs. suie. All accident sequences have essentially zero regional econoinic impacts in five wind directions. Source: Bureau of Economic Analysis, U.S. Department of Commerce, with assumptions supplied by the U.S. Nuclear Regulatory Commission. i t b V V (D 3 x n
m o C e9
=r Table F.6b Regional economic impacts on output and employment: 1985 source tein release sequences --4 to X Direct losses $ Loss in employ- Expected less Accident Wind Nonagri- Agricul- Indirect Total ment, annualized in output per h$ Loss sequence direction cultural tural ' losses losses number of jobs reactor year m
Maximum 12 NNE 402* 124* 64* 590*. 29t <1* 2 NNE 73* 116* 23* 212* 12t 1* 6 NNW 0" .68* 10* 78* 5t 1* Minimum All All O 0* 0* 0* Of 0* Risk /r y 12 All 59** 88** 17** 164** Ott - 2 All 1** 8** 1** 10** Ott - 6 All 0** 0** 0** 0** Ott - Total risk /r y All All 83** 358** 49** 490** Ott -
- Millions of 1980 dollars.
**1980 dollars, bn tThousands of jobs.
f tNumber of jobs. Note: All accident sequences have essentially zero regional economic impacts in five wind directions. Source: Bureau of Economic Analysis, U.S. Department of Commerce, with assumptions supplied by the U.S. Nuclear Regulatory Commission, 3= V V (D 3 b. u T
T Table F,7a Conditional mean values of societal consequences from individual release categories: E 1980 source term
- r a
. Release category 3 Consequences category PWR-1 V TMLB'6 PWR-3 S 2C-6 PWR-5 PWR-6 PWR-7 PWR-8 PWR-9 Early fatalities with supportive 8(-1)* 0 0 0 0 0 0 0 0 0 medical treatment (persons)
Early injuries (persons) 5(1) 9(-5) 3(-2) 0 0 0 0 0 0 0 Delayed cancer fatalities,- 2(3) 3(3) 2(3) 2(3) 2(3) 3(3) 1(2) 4(0) 6(1) 2(-1) including thyroid (persons) Total person rem 3(7) 5(7)- 3(7) 3(7) 4(7) 5(7) 2(6) 6(4) 1(6) 3(3) Cost of offsite mitigation 9(8)- 1(9) 7(8) 3(8) 6(8) 2(9) 2(6) 8(5) 7(5). 1(2) measures (1980. dollars) Land area for long-term 2(8) 3(8) 1(8) 7(7) 1(8) 3(8) 7(4) 0 7(4) 0 interdiction (m2 )
*8(-1) = 8x10 1 = 0.8 Note: Release categories are described in Appendix G of this environmental statement.
i ! kI la ~ n 4 x rt e - _ - . - - _ _ _ _ _ - - _ . - - - _ . - . _
Table F.7b Conditional mean values of societal consequences from individual release categories: 1985 source tere e Release category t vi Consequences category 1 2 3 4 ~5- 6 7 8 9 10 11 12 13 14 S M Early fatalities with supportive' 0 0 0 0 0 0 0 0 0 0 0 0. 0 0 medical treatment (persons) Early injuries (persons) 0 7(-2)* O 4(-3) 0 0 0 0 0 0 4(-5) 1(-2) 0 0 Delayed cancer fatalities, 2(3) 1(3) 5(2) 2(1). 3(3) 1(3) 5(1) 5(0) 3(2) 2(2) 2(3) 3(3) 1(0) 9(-2) including thyroid (persons) Total person-rea 3(7) 2(7) 1(7) 4(5) 5(7) 2(7) 9(5) 6(4) 6(6) 4(6) 3(7) 4(7) 2(4) 7(2) Cost of offsite mitigation 9(7) 9(7) 9(6) 7(5) 6(8) 3(7) 5(5) 6(5) 6(6) 3(6) 1(8). 7(8) 3(5) 3(5) measures (1980 dollars) Land area for long-tern 2(7) 2(7) 2(4) 0 1(8) 4(6) 0 0 7(4) 2(5) 3(7) 2(8) 0- 0 interdiction (m2 )
*7(-2) = 7 x 10 2 = 0.07 Note: Release categories are described in Appendix G of this environmental statement.
N i a
>T n
APPENDIX G ACCIDENT RELEASE CATEGORY DESCRIPTION The consequence analysis of accidents at the South Texas plant is based on in-formation generated from the U.S. Nuclear Regulatory Commission's 1985 Accident Source Term Program Office (ASTP0) study (NUREG-0956) on new source term and on.a 1980 understanding of fission product release (NUREG-0773) referred to as rebaselined reactor safety study (1980) source terms. Both are discussed below. G.1 Rebaselined Reactor Safety Study (1980) Source Terms The first step toward assessing the consequences of severe reactor accidents at the South Texas plant was.to assume the Surry plant (as defined in the Reactor Safety Study (RSS) (NUREG-75/014, formerly WASH-1400), but rebaselined (NUREG-0773) with improved methods relative to the original WASH-1400 method-ology) to be located at the South Texas Project site. The source terms c M.u-lated in the RSS and rebaselined study were then used with site-specific a'.. to calculate offsite risk. The only changes that were made to the rebaselined source terms were the frequency of the containment bypass sequence and the reactor power level to reflect the South Texas conditions. Table G.1 presents the rebaselined accident characteristics for Surry. The symbols for the release sequences are defined in Table G.2 and the release categories are defined in Table G.3. Table G.1 shows that the release frequencies are largely identical (except for event V) to those given in the RSS-rebaselined study (NUREG-0773). However, for the South Texas plant, the residual heat removal (RHR) system is located inside containment and thus the interfacing system loss-of-coolant accident (LOCA) sequences associated with the RHR system are. eliminated by design. The overall release frequency of sequences leading to containment bypass must, therefore, be significantly lower than figures for the Surry plant. The figure 10 7 per reactor year reflects an order of magnitude reduction over the RSS value. In order to recognize the marked differences between the event V (low pressure sequence, long-release duration, low-release energy, high source term) and the TMLB'S (high pressure sequence, low-release duration, high-release energy, lower source term), the PWR-2 release category has been partitioned and spe-cific release categories have been assigned to these two important sequences. Furthermore, a specific release category is now assigned to the $ C-6 2 sequence to reflect-the fact that 5 2 C-6 was the dominant contributor to the original RSS PWR-3 release frequency. From a comparison of the S C-6 2 and PWR-3 source terms in Table G.1, it is apparent that enough differences exist to warrant the separation. A short description of each of the release categories (taken from Appendix VI of NUREG-75/014 is repeated below to help characterize the physical processes South Texas DES 1 Appendix G
l associated with the postulated containment failure mechanisms. More-detailed analyses and descriptions of these accidents and associated processes are given in appendices V, VII, and VIII of NUREG-75/014. PWR-1 This release category is characterized by a core meltdown followed by a steam explosion resulting from contact of molten fuel with the residual water in the reactor vessel. It is assumed that the steam explosion would rupture the upper portion of the reactor vessel and breach the containment barrier, with the re-sult that a substantial amount of radioactivity might be released from the con-tainment in a puff over a period of about 10 minutes. If the containment is at an elevated pressure at the time of the steam explosion, the containment will fail because of a very high sensible energy release. With a low containment pressure, as would be the case if the containment safety features are available, a lower sensible energy release would still occur because of the steam generated by the steam explosion itself. The sweeping action of gases generated following reactor vessel melt-through and during containment vessel melt-through would continue, but at a relatively lower rate. The total release was estimated to contain approximately 70% of the iodines and 40% of the alkali metals present in the core at the time of release.* This category also includes certain poten-tial accident sequences that would involve the occurrence of core melting and a steam explosion after containment rupture because of overpressure. In these sequences, the rate of energy release at the time of the steam explosion would be somewhat lower, although still relatively high. PRW-2 This category is representative of accident sequences in which containment failure' takes place relatively soon .after core melting, implying failure of core-cooling systems concurrent with the failure of containment spray and heat-removal systems. The cantainment barrier would fail as a result of overpressure caused either by excessive steam generation or hydrogen burning, causing a sub-stantial fraction of the containment atmosphere to be released in a puff over a period of about 30 minutes. Because of the sweeping action of gases generated by containment melt-through, some release of radioactive material would continue, but at a relatively lower rate-thereafter. The total release would contain approximately 70% of the iodines and 50% of the alkali metals present in the core at the time of release. The high temperature and pressure within contain-ment at the time the containment failed would result in a relatively high release rate of sensible energy from the containment. This category is also intended to cover core melting sequences that may be initiated by system ruptures located outside containment. In such sequences, the core is predicted to melt and the releases to bypass essentially the containment and containment mitigating systems. PWR-3 This category involves an overpressure failure of the containment because the containment heat removal system fails; in turn, that system interacts with and fails core-cooling systems. Containment failure would occur before core melting
*The release fractions of all the chemical species are listed in Table G.I.
The release fractions of iodine and alkali metals are indicated here to illustrate the variations in release with release category. South Texas DES 2 Appendix G
commences. Core melting would then cause radioactive materials to be released through a ruptured containment barrier. It is estimated that approximately 20% of the iodines'and 20% of the alkali metals present in.the core at the time of release subsequently would be released to the atmosphere. Most of the release could occur over a period of-about 1-1/2 hours. The driving forces for the release of radioactive materials from containment would be the subsequert melt-down processes and the sweeping action of gases generated by the reaction of the molten fuel with concrete. Since these gases initially would be heated by contact with the melted material, the rate of sensible energy release to the atmosphere would be moderately high. PWR-4 This category involves failure of the core-cooling system and the containment spray system after a loss-of-coolant accident (LOCA), together with a concurrent failure of the containment system to properly isolate. This would result in an l estimated release of almost 9% of the iodines and 4% of the alkali metals present in the core at the time of release. Most of the release would occur continuously over a period of 2 to 3 hours. Because of the restricted leak rate and extended period of release, a relatively low rate of release of sensible energy would be associated with this category. l 'PWR-5 1 This category involves failure of the core-cooling systems and containment iso-lation. It is similar to PWR release category 4, except that the containment spray system would operate to reduce the quantity of airborne radioactive ma-l terial available for leakage and to suppress containment temperature and pres-sure, thus reducing the driving force for leakage. The containment barrier would have a large leakage rate because of a concurrent failure of the contain-l ment system to isolate, and most of the radioactive material would be released j continuously over a period of several hours. Approximately 3% of the iodines l and 0.9% of the alkali metals present in the core are estimated to be released ! in this category of accidents. Because of the operation of the containment heat removal systems, the energy release rate would be low. PWR-6 This category involves a core meltdown because of failure in the core cooling systems after a LOCA or transient initiating event. The containment sprays are not available for mitigating the radioactive material released into the contain-ment, but the containment barrier is predicted to retain its integrity until the molten core proceeded to melt through the concrete containment base mat. The containment pressure would remain relatively high, but below the estimated fail-ure pressure. The radioactive materials would thus be released into the ground, some leakage to the atmosphere would occur upward through the ground, and most of the atmospheric release would be noble gases. The radioactive materials would i 1 leak directly to the atmosphere at a low rate before pressure was relieved after containment vessel melt-through. It was also assumed that this direct leakage occurred at a volumetric rate of ~1%/ day. Most of the release wculd occur ccn-tinuously over a period of about 10 hours. The release would include approxi-mately 0.08% of the iodines and alkali metals present in the core at the time of release. Because leakage from containment to the atmosphere would be low and gases escaping through the ground would be cooled by contact with the soil, the energy release rate would be very low. South Texas DES 3 Appendix G
PWR-7 This category is similar to PWR release category 6, except that containment sprays would operate to reduce the containment temperature and pressure as well as the amount of airborne radioactivity. The release would involve 0.002% of the iodines and 0.001% of the alkali metals present in the core at the time of release. Most of the release would occur over a period of 10 hours. As in PWR release category 6, the energy release rate would be very low. PWR-8 This category approximates a PWR design-basis accident (large pipe break), ex-cept that the containment would fail to isolate properly on demand. The other engineered safeguards are assumed to function properly. The core would not melt. The. release would involve approximately 0.01% of the iodines and 0.05% of the alkali-metals. Most of the release would occur in the half-hour period during which containment pressure would be above ambient pressure. Because con-tainment sprays would operate and the core would not melt, the energy release rate would also be low. PWR-9 This category approximates a PWR design-basis accident (large pipe break) in which only the activity initially contained within the gap between the fuel pel-let and cladding would be released into the containment. It is assumed that the minimum required engineered safeguards would function satisfactorily to re-move heat from the core and containment. As in PWR-8 the core would not melt; the release would occur over a 30-minute time period; and the energy release rate would be very low. G.2 1985 Source Terms The RSS-based source terms were described in Section G.I. .These source terms are generally believed to be conservative and, as such, the perceived risk esti-mates are expected to be higher than is really the case. In order to obtain a better perspective of the risk profile associated with the South Texas Project, a second approach was also considered. In this approach, the frequencies of the dominant accident sequences were as-sumed to remain at the RSS values, but the containment response characteristics were assumed to follow the Severe Accident Risk Reduction Program (SARRP) re-sults (NUREG-0956); the radiological source terms were obtained from the recent NRC-sponsored source term. study, BMI-2104, (Battelle, 1984). The only complete and published information on these studies (NUREG-0956) relates to the Surry plant. Consequently, the Surry source terms were again assumed to be applicable l to South Texas. However, the frequency of the containment bypass sequence was again reduced to reflect the South Texas RHR location, and the reactor power level was also adjusted accordingly. Table G.4 presents the containment matrix and the consequence bin assignments l for Surry. The source term consequence bins are summarized in Table G.5 and their respective frequencies are given in Table G.6. South Texas DES 4 Appendix G
The following description of the accident bin assignments is taken from NUREG-0956, Appendix D. Bin 1. This bin is used for sequences with high reactor coolant system pressure during meltdown and involving early containment failure in which sprays are postulated to either not operate or fail at the time of containment failure. The basis for the analysis is a BMI-2104 (Battelle, 1984) calculation, the sta-tion blackout sequence with overpressure failure of the containment (TML8'6). In this sequence, the sprays do not operate and, therefore, the use of this bin for sequences in which sprays operate up to the time of the containment failure (for instance, ATWS) may be an overestimate of the release fractions for those sequences. However, much of the releases from the fuel are retained within the reactor coolant system until vessel failure for these high pressure sequences, and would not be subjected to the sprays anyway. This bin is also used for the no-spray. case for the Reactor Safety ~ Study early containment failure because of an in-vessel steam explosion (a failure mode). A recent evaluation shows that the enhanced ruthenium release assumed in the Reactor Safety Study during a steam explosion is not likely to occur. On the basis of that work, separate source term bins were not required for steam explosion failures. Bin 2. This bin is analogous to Bin 1 except that sprays are assumed to con-tinue to operate following contair.nent failure. Fission product-release frac-tions were developed for the bin .isino the TMLB'6 results for the early in-vessel release period, and results from the small-break LOCA sequence with con-tainment failure due to hydrogen burning (52 Dy) for the delayed release of the fission products during core-concrete attack because that release is strongly influenced by the presence of water from the sprays. In calculating the wash-ing out of fission products by the containment sprays, a single drop size was used. Since the spray heads actually produce a spectrum of drop sizes and drops tend to grow by agglomeration as they fall, an average value must be assumed. A best-estimate drop size of 400 microns was used, although evaluations for the' Quantitative Uncertainty for the Source Term (QUEST) Program indicated that the average drop size could range between 300 and 1200 microns. Bin 3. This bin is another early containment failure bin, but for sequences where the reactor coolant system is at moderate or low pressure during the core melting period. As a result, the amount of retention of radionuclides in the reactor coolant system is reduced. This bin is used to represent sequences in which the containment spray fails at the time of containment failure. The S2 Dy analysis from BMI-2104 (Battelle, 1984) was used to characterize the bin. This bin is also used for those steam explosion failure cases where sprays are postulated to operate until the time that an explosion was postulated to have occured. Bin 4. This bin is comparable to Bin 3 except that the spray system is postu-lated to operate after containment failure. An S2 Dy analysis with continued spray operation was used as the basis for fission product-release estimates for the bin. Bin 5. This bin is only used to represent sequences in which containment failure would precede core melt; i.e., those sequences where containment heat removal is lost. A large LOCA with failure to isolate (ABp) without auxiliary building retention was used to approximate the early phase of the accident. 5 Appendix G South Texas DES
l Since there are many hours of delay before core meltdown, it was felt that the
~
core-concrete release of the less volatile materials as analyzed for the TMLB'6 i g sequence would be most repre.sentative. Bin 6. This bin is only used'to represent the isolation failure cases in which
- sprays are not operating. A TMLB's sequence, which was used to characterize
- the bin, was available. In the sequence analyzed, the postulated location of the failure would lead to a direct release to_the environment. This bin is F used for failures leading directly to the environment as well as those leading to the auxiliary building. No calculation was available for est'.1ating reten-tion in the auxiliary building, and the Reactor Safety Study . .1ot consieer '
any such retention. Bin 7. This bin is used to represent all failure-to-isolate cases with sprays
~
operating. An S2 08 case is used to characterize the bin. The effect of the sprays in reducing the airborne concentrations of aerosols is so great that it dominates the other characteristics of the accident sequence. Bin 8. This bin represents late failure cases caused by hydrogen burns. A TLMB'y case with delayed operation of containment sprays was used to character-ize this bin. This characterization may have larger release fractions than would be the case for other. sequences in which the spray system operates through-out the entire accident. The effect is not expected to be great, however, because of the delayed nature of the' failure. Bin 9. This bin is used to represent a variety of delayed failures: late over-a pressurization without containment heat removal, hydrogen burns resulting from ! deinerting by steam condensation on structures, deinerting hydrogen burns in which the spray system is turned on late and fails at the time the containment fails, and hydrogen burns in which the spray system fails as the result of con-tainment failure. The TMLB'6 case (with release to the atmosphere rather than the ground) that was used to characterize this bin is most representative of the late overpressurization cases without heat removal. Although most of these cases (TMLB' is the exception) have sprays operating early in the accident, the in-vessel release is not particularly important because of the extended time to containment failure. _The containment behavior during core-concrete attack is comparable to that of the TMLB' scenarios for these other cases. Bin 10. In the scenarios represented by this bin, the containment leakage increases with pressure at a rate sufficient to prevent overpressure rupture but not to depressurize the containment. A case of this type, TMLB' leak, has been performed with the BMI-2104 (Battelle, 1984) codes. In most of the sce-narios represented by the bin, sprays would have operated early in the accident i and the bin may have a large in-vessel release contribution to the source term. The ex-vessel release, however, is much more important for this type of scenario with delayed containment failure. ! Bin 11. This bin is only used to represent the event V sequence in which the failure location in the safeguards building occurs below the level of water l discharged from the refueling water storage tank. In this case, separate treat-ment was not available for all the Reactor Safety Study chemical element groups; i only the release fractions for the volatile radionuclides were explicitly tracked s and reported in Volume V of BMI-2104 (Battelle, 1984). Release fractions for the other chemical element groups were inferred from the NAUA code calculation i South Texas DES 6 Appendix G
. _ - - . _ - . = . _ - - _ . -_. -.- -_ - -
R by assuming that all the less volatile fission products are transported with the same attenuation as the gross aerosol (a good approximation). Bin 12. This bin is only used to represent the event V sequence in~which the failure location in the safeguards building occurs.above water. The release
' fractions for the volatile radionuclides for this scenario are provided in Volume V of BMI-2104 (Battelle, 1984). The rest of the groups were inferred from the BMI-2104 results in the same manner as for Bin 11.
Bin 13. Melt-through cases in which the containment is at high pressure at the time of basemat failure are assumed to be characterized by 100% release of noble gases over a 1-hour period beginning 24 hours after accident initiat' >n. There would be some releases of other radionuclides to the ground below the basemat, but the many feet of ground and water above the failure location would provide for effective removal. Because of the very long time to release and the long warning time, the duration of release is unimportant in the consequence calculations. Bin 14. This bin represents the melt-through cases in which the conta'inment is at low pressure at the time of the failure. .Because of the Surry design, water from outside the containment would be forced into the containment raising the pressure to about 20 psi, a pressure that would continue for an extended time. The releases are based on estimates of the noble gases and volatile forms of iodine that would be expected to be released through containment leakage over an extended time at a design rate. Bin 15. This bin represents the cases in which there is neither containment failure nor no core melt. The releases are considered negligible. G.3 Bibliography ! Battelle Columbus Laboratory, BMI-2104, "Radionuclide Release Under Specific LWR Accident Conditions," July 1984. Brookhaven National Laboratory, Technical Report A-3804, " Estimates of Steam. Spike and Pressurization Loads for a Subatmospheric Containment," July 1985 (in preparation). l Houston Lighting & Power Company, " South Texas Units 1 & 2, Final Safety Analysis Report," July 1978. Meyer, J. F. , and W. T. Pratt, direct testimony concerning Commission Question 1, Indian Point Hearings, Docket No. 50-247 and 50-286, 1983. Millstone Point Co., " Millstone-3 Final Safety Analysis Report," May 1984. l Power Authority of New York, " Indian Point Unit 3, Final Safety Analysis Report," December 1970. U.S. Nuclear Regulatory Commission, Memorandum from W. C. Lyon to B. W. Sheron, l
" Observations From Trip to the South Texas Project in Regard to Severe Accidents," ;
i August 5, 1985. i South Texas DES 7 Appendix G 4
..m.-.- - _ - ,. - ----,,. m _. , - - _ . - . , - . - - - - . , , , , , . , - - , - , . _ , -,,---_y.-..m .~ - -, . .--
I l G.3 Bibliography (Continued)
-- , NUREG-75/014, " Reactor. Safety Study," October 1975. -- , NUREG-0773, "The Development of Severe Reactor Accident. Source Term:
1957-1981," November 1982.
-- , NUREG-0850 (Vol. 1), " Preliminary Assessment of Core Melt Accidents at
- the Zion and Indian Point Nuclear Power Plants and Strategies for Mitigating Their Effects," November 1981.
-- , NUREG-0956, " Reassessment of the Technical Bases for Estimating Source
! Terms," Draft Report for Comment, July 1985.
-- , NUREG/CR-3300 (Vol. 2), " Review and Evaluation of the Zion Probabilistic Safety Study: Containment and Site. Consequence Analysis," July 1983.
4
-- , NUREG/CR-4143, " Review and Evaluation of the Millstone Unit 3 Probabilistic Safety Study: Containment Failure Modes, Radiological Source-Terms and Off-Site Consequences," July-1985.
) -- , WASH-1400, See NUREG-75/014. Virginia Electric & Power Co. , "Surry Units 1 & 2 Final Safety Analysis Report," December 1969. r j South Texas DES 8 Appendix G -
-_- -. - .- .. . _ . _ - _ _ - - - ~ . . .
I C . , r,* -Table G.1 Reactor Safety Study rebaselined PWR accident release categories Y Fraction of core inventory released j x Probability / TimD of Ouration C d Warning Wrg
$ reactor release of release time of release l Accident f a sequence year' (hr) (hr) (hr) (10s 8tu/hr) Xe-Kr l' - Cs-Rb Te-Sb Ba-Sr - -Ru La8 Y 1x10 7 2.5 0.5 1.0 20 & 520 0.9 0.7 0.4 0.4 0.05 0.4 3x10 8 j PWR-1 V 1x10 7 2.0 3.0 1.0 1 1.0 0.64 0.82 0.41 0.1 0.04 0.0006 a
TNLB'8 3x10.s 4.5 0.5 1. 0 170 1. 0 0.31 0.39 0.14 0.04' O.02 0.002 PWR-2 Neg 2.5 0.5 1.0 170 0.9 0.7 0.5 0.3 0.06 0.02 4x10 8 PWR-3 3x10 7 5.0 1.5 2.0 6 0.8 0.2 0.2 0.3 0.02 0.01 3x10 8 31.0 3.0 1.5 1.0 0.05 0.33 0.19 0.04 0.02 0.003 ) 52C-6 2x10 8 1 Neg 2.0 3.0 2.0 1 0.6 0.09 0.04. 0.01. 5x10 8 3x10.s 4x10 8 j PWR-4 - PWR-5 5x10.s 2. 0 4.0 1. 0 - 0.1 0.3 0.03 9x10 8 5x10 8 1x10 8 6x10 4' 7x10 8 l PWR-6 6x10 7 12.0 10.0 1.0 n/a 0.3 8x10
- 8x10 8 1x10 8 9x10 5 7x10.s 1xio s PWR-7 3x10.s 10.0 10.0 1. 0 n/a 6x10 8 2x10 8 1x10.s 2x10 s 1,10 s 1x10.e 2x10 7 PWR-8 4x10.s 0.5 0.5 n/a n/a 2x10 s 1x10
- 5x10
- 1x10 8 1x10 8 0 0
- PWR-9 4x10
- 0.5 0.5 n/a n/a 3x10.a 1x10 7 - 6x10 7 1x10 8 1x10 88 0 0 l
i j 'Unsmoothed values are used. ! bTime interval between start of hypothetical accident (shutdown) and release of radioactive material to the atmosphere. c Total time during which the major portion of the radioactive material is released to the atmosphere, dTime interval between recognition of impending release (decision to initiate public protective measures) and the release of radioactive material to the atmosphere.
' Organic fodine is combined with elemental iodines in the. calculations. Any error is neg11 bible since the release 1 fraction is relatively small for all large release categories.
l I Includes Ru, Rh, Co, Mo, and Tc. l , 9 Includes Y, La, Zr, Nb, Ce, Pr, Nd, Np, Pu, Am, and Ca. l 1 8 '
]
i i X O
- Table G.2 Key to RSS-PWR accident sequence symbols l Symbol Accident sequence A Intermediate to large LOCA 8 . Failure of electric power to ESFs B' Failure to recover either onsite or offsite electrical power within about 1 to 3 hours following an initiating transient which is'a loss of offsite ac power C Failure of the containment spray injection system-0 Failure of the emergency core cooling injection system F Failure of the containment spray recirculation system
'G Failure of the containment heat removal system H Failure of the emergency core cooling recirculation system ~
L Failure of the secondary system steam relief valves and the .; auxiliary feedwater system M Failure of the secondary system steam relief valves and the power conversion system Q Failure of the primary system safety relief valves to reclose after opening R Massive rupture of the reactor vessel Si Small LOCA with an equivalent diameter of about 2 to 6 inches 52 Small LOCA with an equivalent diameter of about 1/2 to 2 inches 53 Reactor coolant pump seal failure with loss of injection T Transient event V Low pressure injection system check valve failure a Containment rupture resulting from a reactor vessel steam explosion p Containment failure resulting from inadequate isolation of containment openings'and penetrations T Containment failure resulting from hydrogen burning 6 Containment failure resulting from overpressure c Contiainment vessel melt-through I South Texas DES 10 Appendix G
. . .- . . _ - - _ _ , . . .-. - . - . . . =. ... .
Table G.3 Key to RSS-PWR accident release categories
. Category Definition PWR Steam explosion-induced failure PWR-2 Early failure, no CHRS* and no sprays PWR-3 Intermediate failure, no CHRS* and no sprays PWR-4 Failure to isolate, no CHRS*
PWR-5 Failure to isolate, sprays operating PWR-6 Basemat penetration, no sprays 'l-PWR-7 Basemat penetration, sprays operating PWR-8 Failure to isolate, CHRS* and sprays operating . PWR-9 Containment intact CHRS = containment heat removal system. 1 i 4-l t d 4 South Texas DES 11 Appendix G j
i m O 5
- r Table G.4 Summary of containment matrix and consequence bin assignments
-4
(* Containment Containment Late l 5 failure failure overpressure i e from early from late failure of c2 Containment overpressure hydrogen burn containment m
- failure Containment Containment No
- l. Sequence precedes Spray Spray Spray ^ Spray Containment Containment basemat isolation Containment containment evaluated core melt fails operates falls operates rupture leak melt-through failure bypass failure TLMB' -
0.005* - 0.13 0.38 -0.20 0.02 0.09 0.002 - 0.18 1 9 8 9 10 14 6 15 l 503 0.004 0.04 0.005 0.05 0.15 0.02 0.16 0.002 - 0.58 1 2 9 8 9 10 13 7 15 l 50 - 0.001 0.01 0.006 0.06 0.15 0,02 0.28 0.002 - 0.48 3 4 9 8 9 10 13 7 15 AD - - - - - 0.17 0.02 0.30 0.002 - 0.51 1 9 10 13 7 15-l AF 1.0 - - - - -- - - - - t y 5 N V - - - - - - - - 0.75, 0.25 - 11**, 12***
*For eac5 sequence evaluated, the first row is the conditional probability of the containment failure given a core melt condition, and the second l row is the assigned bin.
** Assumes the break occurs under water.
*** Assumes the break does not occur under water.
l 1 M V V (D 3 CL a. X
u m o
,C y ,
Table G.5 Source term bins Y Time of Duration W rning Elevation Energy of Fraction of core inventory released reletse of release. t{w of release release .
.$ Bia - (hr) (hr) (f.r) (m) (ids 8tu/hr) Xe-Kr 'I Cs-Rb Te-Sb Ba-Sr Ru La o
m 1,3xio.s M 1 2.5 10 0.5 10 2 1. 0 7.5x10 8 5.8x10 8 5.5x10 8 1.0x10. 1.7x10
- 2 1.5 1 0. 5 10 2 1.0 7.5x10 2 5.8x10 2 4.2x10 2 5.1x10.s 1.3x10 8 1.4x10.s 3 2.5 3 0.5 10 11 1.0 5.1x10 8 1.1x10
- 1.1x10 8 3.2x10 2 1.1x10 8 9.4x10
- 4 2. 5 1 0.5 10 0.7 1.0 5.0x10 8 4.8x10.5 2.5x10
- 6.8x10
- 2.6x10 4 1.3x10 8 5 12 10 2 10 2 1.0 3.9x10 8 3.8x10 8 2.0x10 8 8.6x10 2 .1.2x10 2 '1,7xio.4 6 2 10 0 10 2 1.0 2.7x10 2 1.3x10 8 1.2x10 8 6.2x10 8 1.6x10 8 2.6x10
- 7 1 10 0 10 0 1.0 5.3x10 8 2.6x10
- 1.8x10 *- 1.8x10
- 2.7x10 5 5.8x10 7
{. I 8 8 1 6 10 0.7 1.0 5.0x10 8 <1x10.s 1.5x10 8 1.2x10 5 4.3x10
- 2.1x10 *
! 9 12 1 10 10 1.1. 1.0 7.8x10 8 3.9x10
- 8.5x10 2 - 1.8x10 2 3.3x10.s 8.1x10.s 10 2. 5 10 0.5 10 0.2 ' 1. 0 6.9x10 8 1.1x10 8 '1.3x10 2 5.$x108 1.7x10
- 2.4x10.s 11 1 2 0.8 0 3.4 1.0 8,4x10 2 7.3x10 8 2.5x10 2 2.2x10 2 4,5,10.s 1.1x10.s w 12 1 2 0.8 0 3.4 1.0 4.1x10 8 4.0x10 8 1.2x10 8- 1.3x10 8 2.7x10 8 6.4x10 s w 0 0 13 24 1 22 0 -
- 0. 1.0 0 0 0. 0 14 24 1 22 10 0' 3x10 2 1.5x10
- 0 0 0 0 0
* *
- a e a n j 15 i
i " Negligible. 1 d i > g ,, I 1 l O _ _ _ _ _ _ _ _ . , - m_ --3-. , . e 9 - 7ry.__ ___ , .m %
l Table G.6 Assignment of Reactor ; Safety Study fre- l quencies to NUREG-0956 source term bins and C-matrix (per reactor year) Bin Frequency / year 1 4.1x10 8 2 2.4x10 7 3 3.1x10 7 4 3.1x10 7
- 5 2.7x10 7 6 6.6x10 9 7 6.8x10 8 8 2.7x10 8 9 6.6x10 6 10 7.5x10 7 11 3x10 6 12 1x10 6
, 13 3x10 7
', ' , . , 14 8.5x10 6
, 15 2x10 5 South Texas DES 14 Appendix G
% 4 APPENDIX H CONSEQUENCE MODELING CONSIDERATIONS H.1 Evacuation Model ,,
o " Evacuation," used in the context of offsite emergency response in the event of substantial amount of radioactivity release to the atmosphere in a reactor accident, denotes an early and expeditious movement of people to avoid exposure to the passing radioactive cloud and/or to acute ground contamination in the wake of the cloud passage. It sndu?d be distinguished from " relocation" which denotes a postaccident response to reduce exposure from long-term ground contami-nation after the radioactive plume,has passed. The U.S. Nuclear Regulatory Commission's Reactor Safety Study! (RSS) (NUREG-75/014, formerly WASH-1400) con-sequence model contains provision for incorporating radiological consequence
'eductionbenefits'ofpublicl evacuation. A properly planned and expeditiously r
carried out public evacuation in the event of a very large release of fission products would reduce early and latent health effects associated with early exposure. The evacuation model originally used in the RSS consequence model is described in NUREG-75/014 as well as in NUREG-0340 and NUREG/CR-2300. The evacuation model which has been used herein is a modified version of the RSS model developed by Sandia National Laboratory (Sandia,1978) and is, to a certain extent, oriented to site emergency planning. The modified version is briefly outlined below. The model utilizes a circular area with a specified radius [the 16-km (10-mile) plume exposure pathway Emergency Planning Zone (EPZ)], assuming the reactor at the center. It is assumed that people living within portions of this area would evacuate if an accident should occur involving imminent or actual release of significant quantities of radioactivity to the atmosphere.
.Significant atmospheric releases of radioactivity would, in general, be preceded by from less than one to many hours of warning time (postulated as.the time in-terval between the awareness of impending core melt and the beginning of the release of radioactivity from the containment building). For the purpose of cal-culating radiological exposure, the model assumes that all people who live in a 4 fan shaped area (fanning out from the reactor), within the circular zone with 6"
the downwind direction as its median--that is, those people who would potentially be under the radioactive cloud that would develop following the release--would leave their residences after lapse of a specified amount of delay time
- and then evacuate. The delay time is reckoned from the beginning of the warning time and is recognized as the sum of the time required-(1) by the reactor oper-ators to notify the responsible authorities; (2) by the authorities to inter-
- pret the data and decide to evacuate; (3) by the authorities to direct the people to evacuate; and (4) by the residents to mobilize and get under way.
- Assumed to be of a constant value, I hour, that would be the same for all evacuees.
( South Texas DES 1 Appendix H l l .
The model assumes that each evacuee would move radially outward
- away from the reactor with an average effective speed ** (obtained by dividing the zone radius by the estimated average time taken to clear the zone after the delay time) over a fixed distance from the evacuee's starting point. This distance is selected to be 24 km (15 miles) (which is 8 km or 5 miles more than the i 16-km (10-mile) plume exposure pathway EPZ radius). After reaching the end of the travel distance, the evacuee is assumed to receive no further radiation exposure. I I
The model incorporates a finite length of the radioactive cloud in the downwind 1 direction that would be determined by the. product of the (1) duration over which the atmospheric release would take place and (2) average wind speed during the release. It is assumed that the front and the back of the cloud would move with an equal speed which would be the same as the prevailing' wind speed; therefore, its length would remain constant at its initial value. At any time after the release, the concentration of radioactivity is assumed to be uniform over the length of the cloud. If the delay time were less than the warning time, then all evacuees would have a head start; that-is, the cloud would be trailing behind the evacuees initially. On the other hand, if the delay time were more than the warning time, then depending on initial. locations of the evacuees, there are possibilities that (1) an evacuee will still have a head start, or (2) the cloud would be already overhead when an evacuee starts to leave, or (3) an evacuee would be initially trailing behind the cloud. However, this initial picture of cloud / people disposition would change as the evacuees travel, depending on the relative speed and positions between the cloud and people. The cloud and an evacuee might overtake one another one or more times before the evacuee would reach his/her destination. In the model, the radial position of an evacuating person, either stationary or in transit, is compared to the front and the back of the cloud as a function of time to determine a realistic period of exposure to airborne radionuclides. The model calculates the time periods during which people are exposed to radionuclides on the ground while they are stationary and while they are moving out. Because radionuclides would be deposited continually from the cloud as it passed a given location, a person who is under the cloud would be exposed to ground contamination less concentrated than if the cloud had completely passed. To account for this, at least in part, the revised model assumes that persons are: (1) exposed to the total ground contamination concentration that is calculated to exist after complete passage of the cloud, after they are completely passed by the cloud; (2) exposed to one-half the calculated concentration when anywhere under the cloud; and (3) not exposed when they are in front of the cloud. Dif-ferent values of the shielding protection factors for exposure from airborne
, radioactivity and ground contamination have been used.
Results shown in Section F.5 of Appendix F of this environmental statement, for accidents involving significant release of radioactivity to the atmosphere, were
~
based upon the assumption that all people within the 16-km (10-mile) plume ex-posure pathway EPZ would evacuate according to the evacuation scenario described 1
*In the RSS consequence model, the radioactive cloud is assumed to travel radially outward only, spreading out as it moves away. ** Assumed to be a constant value, 5.4 miles (8.6 km) per hour that would be the same for all evacuees.
South. Texas DES 2 Appendix H
above. . Because sheltering can be a mitigative feature, it-is not expected that detailed inclusion of any facility near a specific plant site, where not all persons would be quickly evacuated, would significantly alter the conclusions. For the delay time before evacuation, a value of I hour was used. The staff believes that such'a value appropriately reflects the Commission's emergency. planning requirements. The applicant has provided estimates of the time re-
. quired to clear the 16-km (10-mile) zone.
From these estimates, the staff has conservatively estimated the effective evacuation. speed to be 2.4 meters per second (5.4 mph). It is realistic to expect that the authorities would aid and encourage evacuation at distances from the site where exposures above the threshold for causing early fatalities could be reached regardless of the EPZ distance. As an additional emergency measure for the South Texas site, it was also assumed that all people beyond the evacua_ tion distance who would be exposed to the contaminated ground would be relocated 12 hours after the plume had passed. A modification of the RSS consequence model was used,~which incorporates.the assumption that if the calculated ground dose to the total b'one marrow over a 7-day period were to exceed 200 rems, then this high dose rate would be' detected by actual field measurements following passage of the plume, and people from these regions would be relocated immediately. For this situation, the model limits the period of ground dose calculation to 12 hours; otherwise, the period of ground exposure is limited to 7 days for calculation of early dose. Fig-ure H.1 shows the early fatalities for a pessimisticJcase of no evacuation for 24 hours. The model has the same-provision for calculating the economic cost associated with implementation of evacuation as is in the original RSS model. For this purpose, the model assumes that for atmospheric releases of durations 3 hours or less, all people living within a circular area of 5-mile radius centered at
.the reactor plus all people within a 90 angular sector within the plume expo-sure pathway EPZ and centered on the downwind direction will be evacuated and temporarily relocated. However, if the duration of release would exceed 3 hours, the cost of evacuation is based on the assumption that all people within the entire plume exposure pathway EPZ would be evacuated and temporarily relocated.
For either of these situations, the cost of evacuation and relocation is assumed to be $225 (in 1980 dollars) per person which includes cost of food and tempo-rary sheltering for a period of 1 week. H. 2 Early Health Effects Model The medical advisors to the Reactor Safety Study (NUREG-75/014, Appendix IV, Section 9.2.2 and Appendix F) proposed three alternative dose-mortality rela-tionships that can be used to estimate the number of early fatalities in an exposed population. These alternatives characterize different degrees of post-exposure medical treatment from " minimal," to " supportive," to " heroic"; they.are more fully described in NUREG-0340. There is uncertainty associated with the mortality relationships (NUREG/CR-3185), and the availability and ef-fectiveness of different classes of medical treatment (Andrulis, 1982). Fig-
-ure H.2 shows the early fatalities for a pessimistic case of minimal medical treatment.
South Texas DES 3 Appendix H 8 .. .-. . . _ _ _ _ _ _ _ - - _ _ _ _ _ _ _ _ _
The calculated estimates of the early fatality risks presented in Section F.5(3) of Appendix F of this report used the dose-mortality relationship that is based upon the supportive treatment alternative. This implies the availability of medical care facilities and services that are designed for radiation victims exposed in excess of about 170 rem, the approximate level above which the medical advisors to the Reactor Safety Study recommended more than minimal medical care to reduce early fatality risks. At the extreme low probability end of the spectrum, the number of persons involved might exceed the capacity of facilities that provide the best such services, in which case the number of early fatalities may have been underestimated. However, this number may not have been greatly underestimated because hospitals now in the U.S. are likely to be able to supply considerably better care to radiation victims than the medical care upon which the assumed minimal medical treatment relationship is based. Furthermore, a major reactor accident at South Texas would certainly cause a mobilization of the best available medical services with a high national priority to save the lives of radiation victims. Therefore, the staff expects that the mortality risks would be less than those indicated by the RSS descrip-tion of minimal treatment (and much less, of course, for those who would be given the type of tre ument defined as " supportive"). For these reasons, the staff has concluded that the early fatality risk estimates are bounded by the range of uncertainties discussed in Section F.5(7)of Appendix F of this report. H.3 References Andrulis Research Corp., Task 5 letter report from Dr. D. A. Elliot, Andrulis Research Corp., to A. Chu, NRC Project Officer, on Technical Assistance Contract No. NRC-03-82-128, December 13, 1982. Sandia Laboratories, SAND 78-0092, "A Model of Public Evacuatica for Atmospheric Radiological Releases," June 1978. U.S. Nuclear Regulatory Commission, NUREG-75/014 (formerly WASH-1400), " Reactor Safety Study," October 1975.
-- , NUREG-0340, " Overview of the Reactor Safety Study Consequences Model,"
October 1977.
-- , NUREG/CR-2300, " Draft PRA Procedure Guide. A Guide to the Performance of Probabilistic Risk Assessments for Nuclear Power Plants," April 1982.
-- , NUREG/CR-3185, " Critical Review of the Reactor Safety Study Radiological Health Effects Model," March 1983.
South Texas DES 4 APpendix H !
?C-E 10 10' 16 18 16 16 18 10' 18 - # 10-3 = . . . . . . .....n . . . ..... . . ....n ......n . . . ..... .. . . ..... . . . . . ,
10 ' s : :
- i
- c. -
Q x e, A 10-* =', = 10-' m o :
= _
o , y 10-' '., g 10-' g x : u _ i i : 1
)
o i. w _
\ 10-*
I o 10 ' 3 k. g 7 i ' E m _
- 8. 10 ' g 10-'
3 : x o -
.O 1 0-10 o
1 0-10=- l i 5 L 5 1980 source term . 10 ,, 1985 source term " ' ' ' ' " " ' ' ' ' " ' ' ' ' ' ' " " ' ' ' ' " " ' ' ' ' " " ' ' ' ' " " 10-i,
.g 10 - - - " ~'-10 " "" " " 1'- " '- " ""16" 6 16 16 16 10' 18 i X = Early Fatalities 5
7
=
Figure H.1 Distribution of early fatalities- no evacuation for 24 hours
i i 10' 18 1d 10' 18 18 10' 1d G 10-,10 : ... .nn .. . .on . ....n. . . : . n.. . ...nu .. . . . .n. ......n . .
. . n, 10-g _-
\ o X :- - I m f i
= 10-' s, s : 10-'
e - 1
- := _ ', .
! M -
\s o
1A. x 's c 10-a , = 10_s o : N : w _ s, .
.o _
i x - i i , i e, '- 10-' - 10-' y 5 E I a : : I
- x -.
i :-_ -
- 4 -ia \ _se
.8 10
- : 10 i O :
, u - . a - i _ _1980 source term _ i 10-i,--1985 soyrce term " 10- ,, ,
- 10 10' 18 18 16 18 18 10' 1d m
> X = Early Fatalities u
e 1 o Q. u !' z Figure H.2 Distribution of early fatalities--minimal medical care i.
..y _ - e 4 vv-- _ _ _ _ . _
APPENDIX I HISTORIC AND ARCHE 0 LOGICAL SITES 1 i Appendix I South Texas DES
E Op
'o r.x a a a TEXAS HISTORICAL COMMISSION F.O.BO X 12276 AUSTIN. TEXAS 7878 I (582)475-3092 January 23, 1986 i
P.r. R.W. Lawhn, P.E. Division Manager Environmental Planning & Assessment The Light Company. Houston Lighting & Power P.O. Box 1700 Houston, Texas 77001 Re: South Texas Nuclear Project (NRC,C3,03,F1)
Dear Mr. Lawhn:
We are in receipt of an archeological report concerning the above-referenced under-taking. After reviewing the report, we concur with the author that the portions of site 41CD64 within the right of way are not eligible for the National Register of Historic Places. It is our opinion that site 41CD67 may potentially be eligible for the National Register. However, the right of way appears to be removed from the historic structures. We conclude that ongoing operations and maintenance activities will have no effect upon any properties listed or eligible for the National Register However, there remains the possibility that there may be subsurface sites in the area which may be eligible for inclusion within the National Register. If buried coitural remains are discovered in the course of operations or-ma4ntenance, work should cease in that area and federal regulations pertaining to emergency discovery situations should be followed. The federal agency involved in the project and the Department of Interior (202/343-4101) should be notified. Please also contact our office at 512/475-3057. Thank you for the opportunity to participate in the review process. Sincerely, Q r W LaVerne Herrington, Ph. Deputy State Historic Preservation NK/LH/lft Officer cc: Clell Bond Sde dtak C/Qcyfar .97d/oth 9tmivilkn South Texas DES 1 Appendix I
NAC FOmM 335 U 1L huCLEJ.A LE1ULATOR T COMuisseON i r troM1 NvMet R Mas sw ay Tsoc se var No , st eers a sA. 77a',"3E/- BIBLIOGRAPHIC DATA SHEET 7UREG-ll71
$EE INSTRUCTIONS T>eE REVERSE 2 Vif LE AN0 5v0TtTL JteAvtOLANi Draft Envi snmental Statement Related to Operation of the South Texas 'roject, Units 1 and 2
[ O Af t aff0a f CCW't&Tf D
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Office of Nuclear Reac r Regulation U.S. Nuclear Regulatory ommission Washington, DC 20555 10 SPONSORING ORGANal ATION N AWE AND WA LING ADL ' 55 (sac %de le Cope, 11a f vPt OF REPONT Same as 7. above g PE R:OO COvi#10 e#w4swe def**/ 12 SUPPLEMENT ARY NOTES Docket Nos. 50-498 and 50-499 o s.wTm ACT 1200 eone or 'essi { The information in this statement is th secon assessment of the environmental impact j associated with the construction and ope tio of the South Texas Project, Units 1 and j 2, located in Matagorda County, Texas. Th rst assessment was the Final Environ-mental Statement related to construction, i. ed in March 1975 prior to issuance of construction permits for South Texas. As o ecember 1985, South Texas Unit 1 was 92.3% complete and Unit 2 was 60,1% comple . The projected fuel load date for Unit 1 is June 1987. The present assessment is e rc uit of the NRC staff review of the activities associated with the proposed > ratio of the plant. l l 14 DOCurtNT ANALY5 5 - e stE VWORDS DESCR PTOa5 't av AiLA9'Lif v STATEVENT Unlimited r i
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