ML20101K947
| ML20101K947 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 03/26/1996 |
| From: | Capra R NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20101K950 | List: |
| References | |
| NUDOCS 9604030156 | |
| Download: ML20101K947 (6) | |
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o 7590-01 UNITED STATES NUCLEAR REGULATORY COMMISSION COPMONWEALTH EDISON COMPANY DOCKET NOS. 50-373 AND 50-374 LASALLE COUNTY STATION. UNITS 1 AND 2 ENVIRONMENTAL ASSESSMENT AND FINDING OF NO SIGNIFICANT IMPACT The U. S. Nuclear Regulatory Commission (the Commission) is considering issuance of an exemption from the requirements of Appendix J to 10 CFR Part 50 for Facility Operating License Nos. NPF-Il and NPF-18, issued to Commonwealth Edison Company (Comed, the licensee), for operation of the LaSalle County Station, Units 1 and 2, located in LaSalle County, Illinois.
ENVIRONMENTAL ASSESSMENT Identification of Proposed Action:
Section III.A.5(b) of Appendix J to 10 CFR Part 50 contains acceptance criteria for the maximum allowable measured leakage rates from a plant's primary reactor containment structure for Type A leakage tests at both a reduced pressure and at a peak pressure.
Section III.C.3 of 10 CFR Part 50, Appendix J, contains acceptance criteria for the combined leakage rate for: (1) all primary reactor containment penetrations as defined in Section II.G which are subject to Type B tests; and (2) all containment isolation valves as defined in Section II.H which are subject to Type C tests.
The exemption request will replace a portion of a prior exemption granted in NUREG-0519, " Safety Evaluation Report Related to the Operation of 9604030156 960326 PDR ADOCK 05000373 P
PDR j
LaSalle County Station Units 1 and 2," (SER) dated March 1981, as modified by Supplement No. 6 to that SER, dated November 1983.
7he exemption request will raise the maximum allowable TS value of the main steamline isolation valve (MSIV) leakage rate through all four of the main steamliries to 400 standard l
cubic feet per hour (scfh) from the present value of 100 scfh, This exemption requast was submitted by Comed in its letter dated August 28, 1995, in conjunction with its request for license amendments for Units 1 and 2.
These j
amendment requests propose to delete the present MSIV leakage control system (LCS) and replace this system with an alternate leakage treatment (ALT) path t
for leakage past the MSIVs in the event of a design basis accident loss-of-l coolant (DBA-LOCA).
4 The Need for the Proposed Action:
The proposed exemption would allow the licensee to continue to perform the Type A, B and C tests in the same manner required by 10 CFR Part 50, Appendix J, without penalizing the performance of these primary reactor containment leakage tests by including the proposed increase in the TS l
allowable leakage past the MSIVs.
Specifically, the exemption granted in NUREG-0519 and its supplement cited above, excluded the MSIV leakage from the Type A, B and C tests and the present exemption will also continue to do so but at a higher allowable MSIV leakage rate.
Environmental Imoacts of the Proposed Action:
The radiological consequences of a potential release of fission products e
i through the ALT path would be still subject to the radiation exposure f
guidelines at the site boundary as contained in 10 CFR Part 100 and also subject to the control room dose guidelines in General Design Criteria (GDC) 1 4
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19 of Appendix A to 10 CFR Part 50.
In addition, the licensee has demonstrated that the ALT path would remain structurally sound in the event of the design basis earthquake. Accordingly, granting of the requested exemption will still satisfy the requirement of limiting radiation exposures to acceptable limits in the event of a DBA-LOCA.
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Specifically, both the MSIV leakage and the primary containment leakage, is used to calculate the maximum radiological consequences of a postulated DBA-LOCA as shown in Table 15.2 of NUREG-0519.
(Table 15.1 of Supplement I
No. 6 to NUREG-0519 replaced this earlier table.) Conservative assumptions were used in the staff's reevaluation of the offsite and control room doses, including the doses due to the increased TS allowable MSIV leakage, which could result from a postulated DBA-LOCA.
The staff's analyses demonstrate that the proposed leakage rate of 400 scfh past all the MSIVs results in potential dose exposures to the public which remain within the guideline exposure limits in 10 CFR Part 100. These analyses also demonstrate that the potential doses to the control room personnel meet the requirements in GDC 19 of Appendix A to 10 CFR Part 50.
With respect to the proposed deletion of the MSIV-LCS, this action will reduce the overall occupational radiation dose exposures and reduce the 9eneration of low level radioactive waste due to the elimination of maintenance and surveillance activities asssciated with the present LCS. The dose exposure associated with deleting the LCS will satisfy the as low as reasonably achievable (ALARA) requirements in 10 CFR Part 20 and will be less than the radiation doses which would result from maintenance and surveillance activities associated with the present leakage control system if it were
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_4 continued to be used for the remainder of the station's life. Accordingly, the potential releases will not differ significantly from those determined previously, and the proposed amendments do not otherwise affect facility radiological effluent or occupational exposures.
Therefore, there will not be a significant increase in the types and amounts of any effluent that may be released offsite and, as such, the proposed amendments do not alter any initial conditions assumed for the DBAs previously evaluated. Finally, the proposed ALT path is capable of mitigating the radiological consequences of these postulated DBAs.
Furthermore, the proposed exemption will not result in a significant increase to the LOCA doses previously evaluated against the offsite dose guideline values contained in 10 CFR Part 100 and in the limits in GDC 19 of Appendix A to 10 CFR Part 50.
With regard to potential nonradiological impacts, the proposed actions involve features located entirely within the restricted area as defined in 10 CFR Part 20. They do not affect nonradiological plant effluents and have no other environmental impact. Accordingly, the Commission concludes that there are no significant nonradiological impacts associated with the proposed actions.
The Commission concludes that:
(1) the proposed actions will not increase the probability or consequences of accidents; (2) no changes are being made in the types of effluents which may be released offsite; and (3) there is no significant increase in the allowable individual cumulative occupational radiation exposure nor in radiation exposure of the public.
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Alternatives to the Proposed Action:
l Since the Commission has concluded there is no measurable environmental j
impact associated with the proposed actions, any alternatives with equal or greater environmental impact need not be evaluated. As an alternative to the proposed actions, the Commission considered denial of the proposed actions.
Denial of the application would result in no change in current environmental impacts.
Alternative Use of Resources:
]
This action does not involve the use of any resources not previously 1
considered in the Final Environmental Statement for the LaSalle County Station 4
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dated November 1978.
Accordingly, the impacts of the proposed action and the alterative action are timilar.
Aaencies and Persons Consulted:
In accordance with its stated policy, on February 21, 1996, the NRC staff consulted with the Illinois State Official, Mr. Frank Niziolek, Head, j
Reactor Safety Section, Division of Engineering, Illinois Department of Nuclear Safety; regarding the environmental impact of the proposed action.
The State official had no comments.
FINDING OF NO SIGNIFICANT IMPACT Based upon the environmental assessment, the Commission concludes that the proposed action will not have a significant effect on the quality of the human environment. Accordingly, the Commission has determined not to prepare an environmental impact statement for the proposed exemptior.
For further details with respect to the proposed action, see the request for exemption dated August 28, 1995, which is available for public inspection at the Commission's Public Document Room, The Gelman Building, 2120 L Street, NW., Washington, DC, and at the local public document room, located at the Jacobs Memorial Library, Illinois Valley Community College, Oglesby, Illinois 61348.
Dated at Rockville, Maryland, this 26th day of March 1996.
FOR THE NUCLEAR REGULATORY COMMISSION l
0-i Robert A. Capra, Pro ect Director Project Directorate III-2 Division of Reactor Projects III/IV Office of Nuclear Reactor Regulation i
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