ML20128E323

Environ Assessment & Finding of No Significant Impact Re Consideration of Issuance of Amends to Licenses DPR-80 & DPR-82.Amends Extend License Expiration Dates

ML20128E323
Person / Time
Site:	Diablo Canyon
Issue date:	02/03/1993
From:	Quay T Office of Nuclear Reactor Regulation
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ML20128E327	List: ML20128E323
References
NUDOCS 9302100380
Download: ML20128E323 (16)

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7590-01 UNITED STATES NUCLEAR REGULATORY COMMISSION PACIFIC GAS AND ELECTRIC COMPM1 DOCKET NOS. 50-275 AND 50-323 DIABLO CANYON NUCLEAR POWER PLANT. UNITS 1 AND 2 RQTICE OF ISSUANCE OF ENVIRONMENTAL AS_SESSMENT AND FINDING OF NO SIGNIFICANT IMPACT The U.S. Nuclear Regulatory Commission (the Comission or the NRC) is considering issuance of an amendment to Facility Operating License Nos.

DPR-80 and DPR-82, issued to Pacific Gas and Electric Company (PG&E, the licensee), for operation of the Diablo Canyon Power Plant (DCPP), Units 1 and 2, located in San Luis Obispo County, California.

ENVIRONMENTAL ASSESSMENT Identification of Proposed Action Diablo Canyon Power Plant, Units 1 and 2 are currently licensed for operation for 40 years commencing with the issuance of the construction permits. The operating licenses expire on April 23, 2008, for Unit 1 and on December 9, 2010, for Unit 2.

By letter dated July 9,1992, the licensee requested that the DCPP operating license expiration dates be extended to September 22, 2021, for Unit 1, and to April 26, 2025, for Unit 2 or 40 years after the date of the issuance of the " low-power" operating.

licenses.

The Need for the Proposed Action The proposed change to the license would allow the licensee to operate DCPP, Units 1 and 2, for 40 years from the date of the issuance of the operating licenses, thus recapturing the construction period. This 1

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extension would also permit the plant to operate for the: full 40-year -

-design-basis lifetime, consistent with previously stated Commission policy (Memorandum dated August 16,-1982, from'W1111am'J. Dircks. Executive e

Director for Operations, to the Commissioners) and as evidenced by the issuance for over 50 similar extensions to other licensees, y

Environmental Imoacts of the Proposed Action The Commission has completed its evaluation of the proposed revision i

and concludes that the extension of Diablo Canyon's Operating License Nos.

DPR-80 and DPR-82 will not create any new or unreviewed environmental.

L impacts.

This change does not involve any physical-modifications, and there are no new or unreviewed environmental impacts that were not considered as part of the Final Environmental Statement (FES) dated May 1973, relating to operation of the DCPP, Units 1 and 2.

Evaluations for the FES considered a 40-year operating life.

The considerations involved in completing the Commission's evaluation l.

for the proposed amendment are discussed below.

1.

Radioloaical Impacts of the Hvoothetj_ cal Desian Basis Accident The offsite_ exposure from releases during postulated accidents has been previously evaluated in.the DCPP Final Safety Analysis Report- (FSAR) 1 Update.

The results are acceptable'when_ compared with'the criteria ~ defined-in 10 CFR 100. This type of evaluation is a function of four parameters:.

(1) the. types of accidents postulated, (2) the radioactivity release calculated for'each accident, (3)~the assumed meteorologisal; conditions, and (4) the. population ' distribution versus distance from the plant.. LThe staff has concluded that neither the types of accidents nor the calculated 1

radioactivity releases will change through the proposed 40-year operating 1-i

-3 license terms.

Furthermore, the site meteorology as defined in the FSAR Update is essentially constant and consideration herein is therefore unwarranted.

Thus, population size and distribution is the only time-dependent parameter. The population size and distribution in the vicinity-of the plant have been reviewed several times since the construction permit was issued. The California Department of Finance projections indicated that a compound average growth rate of 2.15 percent is expected for the 50-mile radius around Diablo Canyon through the year 2025. There is no expected change in land usage during the 11 cense terms that would affect offsite dose calculations. The population projections are presented in l

Figure 1, " Summary of Population Projections for the Diablo Canyon i

Vicinity," taken from the licensee's July 9,1992 letter.

j The changes projected for the population distribution through 2025 l

l will not significantly impact any accident analysis previously calculated, Furthermore, the current exclusion area boundary, low Population Zone (LPZ), and nearest population center distance will continue to meet the requirements of 10 CFR 100.11(a) for the proposed 40-year license terms.

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Accordingly, we conclude that the proposed license amendment will not significantly change previous conclusions on the potential environmental effects of offsite releases from postulated accidents.

The Commission stated in its proposed no significant hazards consideration (57 FR-32575) dated July 22, 1992, that the requested change in expiration dates is consistent with current NRC policy and the l

originally engineered design life of the plant, i.e., 40 years of operation. Due to design conservatism, maintenance and surveillance programs, inspection programs and the Plant Technical Specifications, the l

-4 proposed additional thirteen and fifteen years of operation for DCPP Units 1 and 2 will have no significant impact on safety. That is, regardless of the age of the facility, the above mentioned programs and Technical Specifications ensure that components, systems and structures will be refurbished or replaced to maintain their requisite safety function over 40

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years of operation.

2.

83dioloaical Impacts of Annual Releases

a. Onsite Doses The DCPP occupational (onsite) exposure trend and magnitude as compared with the industry's averagt. pressurized water reactor (PWR) site, based on 3-year average annual aposures in terms of person-rem per reactor unit, is shown in Figure 2. "Diablo Canyon vs. INP0 Industry Goal Average Annual Occupational Exposure," taken from the licensee's July 9,1992 letter.

The data in Figure 2 indicate that the licensee has implemented a successful program under 10 CFR 50, Appendix I "As low as Reasonably Achievable" (ALARA) guidelines.

Figure 2 also shows the projected occupational exposure averages per unit through the year 2000. Given the licensee's continued implementation of its ALARA program and DCPP's historical occupational exposure, we conclude that the occupational exposures used in Figure 2 serve as a realistic estimate through the proposed 40-year period of operation. These projected exposures are significantly less than the 450 person-rem per year per unit values estimated in the FES Addendum'for Diablo Canyon. Occupational exposures l

resulting from the proposed 40-year operating license terms will remain well within the limits of 10 CFR 20.

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Offsite Doses Appendix ! guidelines on ALARA were briefly discussed above in regard to onsite doses; these guidelines also apply to releases that could cause offsite doses.

In addition, routine releases to the environment are governed by 10 CFR 20.l(c), which 5 ates that such releases should be as low as reasonably achievable. Appendix ! is more explicit in that it establishes radioactive design / dose objectives for liquid and gaseous offsite releases including iodine / particulate radionuclides.

Figure 3,

" Comparison of Offsite Appendix I Radiation Exposure Limits and Actual Data," provides a comparison of Appendix I limits with consolidated plant operating data.

This figure is derived from the licensee's letter of July 9, 1992.

A review of the values in Figure 3 indicates that the actual performance of the plant to control and limit liquid and gaseous radioactive releases has been well within the Appendix I limits.

Based on the continued operation of the plant's existing Waste Processing System, we cunclude that the anticipated offsite doses during the period covered by the proposed license amendment would remain a fraction of 10 CFR 50, Appendix I limits. The projected exposures are also well within the offsite exposures estimated by the NRC in the Diablo Canyon's FES.

Furthermore, the plant's contribution to the local population dose within a 50-mile _ radius is expected to remain insignificant in comparison to that from background radiation.

The DCPP Radiological Environmental Monitoring Program was established prior to the start of plant operation to determine preoperational background levels. The Radiological Environmental Monitoring Program is designed to validate the adequacy of safeguards t

inherent in plant design and the effectiveness of dose calculations, based on plant emission data and appropriate meteorological and aquatic dispersion models.

Emphasis is placed on control at the source, with follow-up and confirmation by environmental surveillance. This is accomplished by continuously measuring radiation levels and airborne radioactivity levels and periodically measuring amounts of radioactivity in samples at various locations surrounding the plant. To ensure that the program continues to include environmental. sample locations most likely to detect plant-related radioactivity, a land-use census is conducted annually.

Changes in milk sampling locations may be required following the census based on relative potential doses or dose commitments and the availability of samples. Continued environmental monitoring and surveillance under this program ensures early detection of any increase in exposures over the proposed 40-year operating license terms.

The volume of solid low level radioactive waste generated at DCPP has historically been among the lowest in the nuclear power industry.

In addition, the licensee has committed to further reduce the amount generated in future years.

We conclude that the releases from DCPP, both onsite and offsite, have remained within the bounds of the FES and have complied with the applicable portions of 10 CFR Parts 20 and 50, as discussed above. As a consequence, we would expect releases during the proposed license extension period to remain within these bounds.

3.

Environmental imoact of the Uranium Fuel Cycle Each Diablo Canyon reactor contains 193 fuel assemblies.

The assemblies consist of fuel rods in a 17 x 17 array. About 39 to 46 percent I

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of the fuel assemblies are replaced every refueling. Since issuance of the-operating licenses,:PG&E has adopted several fuel design changes and' improved fuel management schemes. These changes have_significantly improved uranium utilization.

The fuel parameters meet 10 CFR 51.52(a)(2), except for fuel enrichment, which may be as much as 0.5 weight-percent higher in the_DCPP:

fuel rods. The environmental effects of extended fuel burnup and higher initial enrichment are addressed by the NRC in a " Notice of-Environmental Assessment and Finding of No Significant Impact" published in the Federal Reaister on February 29, 1988 (53 FR 6040).

This notice stated that.the-NRC's environmental ' assessment of extended fuel burnup and higher enrichment fuel is-complete, and that the environmental impacts summarized-in Tables S-3 of 10 CFR 51.51 and S-4 of-10 CFR 51.52 bound the-corresponding impacts for burnup levels up to:60 gigawatt-days / metric-_ ton uranium and enrichments up to 5 weight percent U-235.

. c In the Diablo Canyon FES, it was assumed for purposes of estimating-the amount of uranium required that the p1 ant would operate for 40: years 3

with an 80 percent capacity factor._ It was further. assumed that the units-t would be refueled on approximately-'an annualLbasis.- Since lhe~Diablo-Canyon units are refueled.approximately every-18 months and improvements in' uranium utilization have been made, the total amount of uranium required for the proposed 40-year operating license terms-isiexpected to be less than the amount projected in the FES.

The environmental impacts,. both: radiological and nonradiological, attributable to-the transportation of fuel and wastelto and fr)m plant' sites, with_ respect to normal conditions of transport and possible k-

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accidents in transport, have been assessed in several generic environmental impact statements. The assessments represent the contribution of such transportation to annual environmental costs including dose per reactor year to exposed transportation workers and to the general public. These annual environmental costs, which are displayed in Table S-4 of 10 CFR 51.52, would not be changed by the extended period of operation.

Based on the above, we conclude that there are no significant changes in the environmental impact related to the uranium fuel cycle due to the proposed extended operation of DCPP.

4.

Nonradioloaical Impacts The major nonradiological impact of the plant on the environment is the operation of the plant's cooling water system. The DCPP cooling water system is a once-through system discharging directly into Diablo Cove of the Pacific Ocean. The potential ecological effects of the cooling water system are:

(1) those resulting from elevated water temperatures in portions of Diablo Cove, (2) entrainment of organisms in the cooling water system, (3) impingement of organisms on the intake traveling screens, and (4) scouring effects of the discharge in the intertidal zone at the point of discharge.

These effects have been extensively studied and the study results were considered in issuance of the Natiorai Fulluti:;n Discharge Elimination System (NPDES) Permit and renewals. The NPDES Permit is conditional upon the discharge complying with provisions of Division 7 of the California Water Code and of the Clean Water Act (as amended or as supplemented by implementing guidelines and regulations) and with any more stringent

effluent limi_tations necessary to implement water quality control plans, to protect beneficial uses, and to prevent nuisance.

An April 28,19B8 study of the cooling water intake structure was submitted to the California Regional Water Quality. Control Board, which concluded the facilities at DCPP reflect the best technology available (BTA). Further, the Monitoring and Reporting Program requires PG&E to continue ecological studies as approved by the Executive Officer to evaluate changes in distribution und abundance of marine plants and animals within the vicinity of the discharge. These operational _ studies have indicated that the effects of the discharge are consistent with the preoperational studies and modelling predictions; i.e., that the-discharge would not significantly affect the marine 'cology in the vicinity of.DCPP.

The Board and Department of Fish and Game have found the observed-changes (mainly in relative abundance of f.pecies) to be acceptable, o

L Additional discht.rge and thermal effects are not anticipated based-on.

operational data collected since 1984.- Accordingly,-the basis for the-Board's order is expected to remain-valid when the NPDES Permit is renewed in 1995 and thereafter.

Other nonradiological impacts of the proposed license extension.

involve the' following factors:-

a. Short-Tern Use Versus Long-Term Productivity L

The ?ifetime capacity factor for DCPP~ through'its first 7 years of-commercial operation is about 77 percent.

The plant has maintained an excellent safety record during this_ period and recent NRC Systematic-Assest. ment of Licensee Performance:(SALP): reports have found the performance of licensed activities to be very gcod and in some cases to be y

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superior. The licensee has achieved a high level of safety performance and recently met NRC criteria for recognition of its good-performance. The staff expects that a good level of performance will continue during the remaining license period and during the requested extension period,

b. Irreversible and Irretrievable Comitment of Resources The FES stated in its discussion of this factor, in regard to the initial plant construction as well as 40 years of projected operation, that the resource consumption is justified in view of the electrical energy to be produced by the plant. The NRC has not determined the need for ary significant resource commitments necessary as a result of the proposed lice.:e extension.

c. Histv.ic Preservation PG&E continues to manage and protect the historic properties at DCPP in consultation with the California State Historic Preservation Office and the local Native American comunities. As a result of this aggressive management, the Commission concludes, as it did in a letter to PG&E dated June 25, 1984, that operation of DCPP throughout the 40-year operating license terms will not adversely affect any known historic sites.

5. Plant Modifications Several environmental-related plant modifications have been made since issuance of the FES and Addendum. Those that involve an unreviewed safety question or require a change to the Technical Specifications are submitted'to the NRC for prior review and approval. This review includes a determination of the environmental effects of the proposed change. As provided by our regulations, other changes may be implemented without prior NRC approval. The licensee must first perform a safety evaluation for any

such change, subject to NRC inspection and audit.

The licensee also submits on a refueling outage basis, a sumary of such changes to the NRC for its review.

The update of the FSAR also includes a description of such changes and a summary of the safety evaluation. The staff reviews the FSAR updates to verify that the changes did not require prior NRC review and approval.

In general, these changes further reduce the environmental impacts associated with DCPP operation.

Some of the modifications include:

wastewater holding and treatment system, hazardous waste storage, oil spill prevention, expanded sewage treatment, chlorination system modifications and makeup water treatment. Most of these plant design modifications and changes have had a direct positive impact on the environment; for example, chemical discharges have decreased and spill prevention has improved.

Additional plant modifications and changes may be implemented during the proposed 40-year operating license terms. Based on past experience, future changes are not expected to have any adverse impact on the environment.

6. Conclusion on Environmental Imoacts In summary, the effects of changing the expiration date for the Unit 1 Operating License from April 23, 2008, to September 22, 2021, and the expiration date for the Unit 2 Operating License from December 9, 2010, to April 26, 2025, are bounded by the assessment in the original FES.

In addition, based on the above, the Commission concludes that there are no significant environmental impacts associated with the proposed amendment.

Alternative to the Procosed Action Since the Commission concluded that there are no significant environmental effects that would result from the proposed action, any

q alternatives with equal or greater environmental impacts need not be i

evaluated.

However, the principal alternative would be to deny the H

requested amendment.

If the plant is not operated beyond 2008.- it is likely that it would be necessary to construct new baseload capacity.

Even i

considering significant changes in the economics of the alternatives for producing an equivalent electrical power capacity, operation of DCP'P during the requested extension period would only require incremental yearly costs.

These costs would be substantially less than the installation of new electrical generating capacity. Moreover, the overall cost per year of the facility would decrease since the large initial capital outlay would be averaged over a greater number of years.

In summary, the cost-benefit advantage of DCPP compared to alternative electrical power generating.

capacity improves with the extended plant lifetime.

Alternative Use of Resources This action does not involve the use of resources not previously.

considered in the Final Environmental Statement related to operation of Diablo Canyon, dated May 1973.

Aaencies and Persons Consulted

-The Notice of Consideration of Issuance of Anendment and Opportunity for Hearing in connection with this action was published in the Federal-Reaister on July 22, 1992 (57 FR 32575).

In accordance with 10 CFR 2.714 (b), the San Luis Obispo Mothers for Peace, on August 21, 1992, filed:a-4 petition for-leave to intervene.and requested a hearing; the action _has resulted in contacts between the staff and the Mothers for Peace.

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ElllDING Of NO SlfiNIFICANT IMiAll The conclusions of the May 1973 Final Environmental Statement (fES) remain valid and operation of the plant has demonstrated that its impact on the environment has been within the bounds predicted by the FES for 40 years v operation.

Based on its review of the proposed license amendment relative to the requirements set forth in 10 CFR 51, the Comission concludet that there are no significant radiological or nonradiological impacts associated with the propmed action and that the issuance of the proposed license amendment will not have a significant effect on the quality of the human environment. Therefore, pursuant to 10 CFR 51.31, an environmental impact statement need not be prepared for the proposed license amenciment.

For furthee details with respect to this action, see the licensee's e.pplication for amendment dated July 9,1992, which is available for public inspection at the Commission's Public Document Room, Gelman Building, 2120 L Street, NW., Washington, D.C. 20555 and at the local public document room at California Polytechnic State University, Robert C. Kennedy Library, Government Documents and Maps Department, San Luis Obispo, California 93407.

Dated at Rockville, Maryland this 3rd day of February 1993.

FOR THE NUCLEAR REGULATORY COMMISSION 26kk. %)

Theodore R. Quay, Director Project Directorate V Division of Reactor Project III/IV/V Office of Nuclear Reactor Regulation 1

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Fir.URE 1 Sumary o,' Population Projections for the Diablo Canyon Vicinity Area Original FSAR Revised FSAR (miles)

(1974)

(1985)

Current Current 2010 2010 2010 2025 0 - 6*

29 26 100 100 6 - 10 18,992 36,126 36,403 46,480 0 - 10 19.021 36,152 36,503 46,580 10 -50 500,130 438,035 r55,108 730,566 0 - 50 527,151 474,187 591,611 777,146

• Reflect > Low Population Zor,e

15 FIGURE 2 Olablo Canyon vs. INPO Industry Goal Average Annual Occupational Exposure Total Dose Refueling (oerson-rem oer rettiar_ unit)

Year Outages DCPP 3-Yr Average INP0 3-Yr Average Goal 1985 1

151 288 1987 1

168 288 1988 2

253 288 1989 1

275 288 1990 1

269 288 1991 2

214 288 1992*

1 199 288 1993*

1 195 288 1994*

2 218 288 1995*

1 202 185 1996*

1 188 185 1997*

2 150 185 1998*

1 150 185 1999*

1 150 185 2000*

2 150 185

• Projected, based on:

18-month fuel cycle operation 3.5 person-rem per non-outage month 1993 based on 80% of 1992 due to dose rate differences between units 50 person-rem savings per outage due to RTD bypass elimination in 1994 1

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FIGURE 3 Comparison of Offsite Apaendix ! Radiation Exposure Limits anc Actual Data DCPP 5-Year Percent of Parameter Appendix 1 Haximum Appendix !

Dose Limits Individual Dose Dose Limit (mrem)

(mrem)

Liquids 53 0.031 1.04 Gases 510 0.212 2.16 lodines and

$15 0.027 0.18 Particulates

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