ML20078L263
| ML20078L263 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 02/01/1995 |
| From: | Rinaldi F Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20078L266 | List: |
| References | |
| NUDOCS 9502100255 | |
| Download: ML20078L263 (6) | |
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4 7590-01 UNITED STATES NUCLEAR REGULATORY COMISSION PHILADELPHIA ELECTRIC COMPANY DOCKET NOS. 50-352 AND 50-353 LIMERICK GENERATING STATION. UNITS 1 AND 2 ENVIRONNENTAL ASSESSMENT AND FINDING OF NO SIGNIFICANT IMPACT The U.S. Nuclear Regulatory Commission (the Commission) is considering two actions:
(1) issuance of an exemption from the requirements of 10 CFR 50, Appendix J, and (2) an amendment to Facility Operating License Nos. NPF-39 and NPF-85, issued to Philadelphia Electric Company (the licensee), for operatiog oftheLimerickGeneratingStation(LGS), Units 1and2,locatedinMontgomehy County, Pennsylvania.
ENVIRONMENTAL ASSESSMENT Identification of the Proposed Action:
The proposed action would grant 1) an exemption from 10 CFR Part 50, Appendix J, Sections II.H.4, III.C.2, and III.C.3, and 2) an amendment to change the Technical Specifications (TS) for the Limerick Generating Station (LGS), Units 1 and 2, in conjunction with the removal of the main steam isolation valva (MSIV) leakage control system (LCS) and the proposed use of an alternate leakage pathway.
10 CFR Part 50, Appendix J, Sections II.H.4 and III.C.2 require leak rate testing of MSIVs at the calculated peak containment pressure related to the design basis accident, and Section III.C.3 requires that the measured MSIV leak rates be included in the combined local leak rate test results. The proposed deletion of the MSIV LCS and proposed use of an alternate leakage pathway affects the description of an existing exemption (NUREG-0991, and its 9502100255 950201 PDR ADOCK 05000352 P
FDR
. Supplement 3), which allows the leak rate testing of the MSIVs at a reduced pressure and allows exclusion of the measured MSIV leakage from the combined local leak rate test results.
The proposed TS amendment would permit an increase in the allowable MSIV leakage rate from 11.5 standard cubic feet per hour (scfh) to 100 scfh for any one MSIV and a combined maximum pathway leakage rate of 200 scfh for all four main steam lines, and would delete TS requirements for the currently installed MSIV LCS, because the proposed system removal makes the TS inapplicable.
The proposed action for the TS amendments is in accordance with the licensee's application for amendment dated January 14, 1994, as supplemented, by letters dated August 1, October 25, December 13, and December 22, 1994; and the proposed action for the exemption is in accordance with a letter dated December 22, 1994.
The Need for the Proposed Action:
The proposed exemption is similar to the current exemption from 10 CFR Part 50, Appendix J, Sections II.H.4 and III.C.2. The exemption is needed since the design of the MSIVs is such that testing in the reverse direction tends to unseat the valve and would result in a meaningless test. The total observed MSIV leak rate resulting from a leakage test where two MSIVs on one steam line are tested utilizing a reduced pressure (22 psig) will continue to be assigned to the penetration. The proposed exemption is also similar to the current exemption from 10 CFR Part 50, Appendix J, Section III.C.3. The licensee proposes that the MSIV leakage rate will continue to be accounted for separately in the radiological site analysis in accordance with the existing 4
_3-exemption. However, the existing exemption from 10 CFR Part 50, Appendix J, Section III.C.3 will not be applicable when the MSIV LCS is replaced with an Alternate Treatment Path (ATP) (main steam lines and condenser).
The proposed ution regarding the TS amendment will reduce the need for repairs of the MSIVs, resolve concerns associated with the current LCS l
performance capability at high MSIV leakage rates, and provide an effective j
method for dealing with a potential MSIV leakage during a postulated loss-of-coolant accident (LOCA). Many boiling water reactors (BWRs) have difficulty meeting their MSIV leakage rate limits. Extensive repair, rework, and retesting efforts have negative effects on the outage costs and schedules, as well as significant impact on the licensee's as low as is reasonably achievable (ALARA) radiological exposure programs. The alternatives proposed by the licensee to deal with MSIV leakage make use of components (main steam lines and condenser) that are expected to remain intact and serviceable i
following a design basis LOCA.
Environmental Imoacts of the Pronosed Action:
The Commission has completed its evaluation of the proposed actions related to the granting of an exemption from 10 CFR Part 50, Appendix J, Sections II.H.4, III.C.2, and III.C.3, and for the TS changes proposed by the l
licensee, and concludes that the proposed actions will not increase the 1
probability or consequences of accidents, no changes are being made in the types of any effluents that may be released offsite, and there is no significant increase in the allowable individual or cumulative occupational radiation exposure.
0 Regarding the exemption, the MSIV leakage, along with the containment leakage is used to calculate the maximum radiological consequences of a design basis accident. Section 15.6.5 of the LGS Updated Final Safety Analysis Report (UFSAR) identifies that standard and conservative assumptions have been used to calculate the offsite and control room doses, including the doses due to MSIV leakage, which could potentially result from a postulated LOCA.
Further, the control room and offsite doses resulting from a postulated LOCA have recently been recalculated using currently accepted assumptions and methods. These analyses have demonstrated that the total leakage rate of 200 scfh results in dose exposures for the control room and offsite that remain -
t within the requirements of 10 CFR Part 100 for offsite doses and 10 CFR Part 50, Appendix A, for the control room doses.
Regarding the TS change, deletion of the MSIV LCS will reduce the overall occupational dose exposures and reduce the generation of low level radioactive waste due to the elimination of maintenance and surveillance activities associated with the system. The dose exposure associated with deleting the system will satisfy the ALARA requirements, and will be less than the dose which would result from maintenance and surveillance activities associated with the present system, if utilized for the remainder of the plant life. Thus,'iradiological releases will not differ significantly from those determined previously, and the proposed amendment does not otherwise affect l
facility radiological effluent or occupational exposures.
Therefore, there will not be a significant increase in the types and j
amounts of any effluent that maybe released offsite and, as such, the proposed l
amendment does not alter any initial conditions assumed for the design basis l
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- accidents previously evaluated and the alternate system is capable of mitigating the design basis accidents.
Furthermore, the proposed exemption will not result in a significant increase to the LOCA doses previously evaluated against offsite and main control room dose limits contained in 10 CFR Part 100 and 10 CFR Part 50, Appendix A, General Design Criteria 19.
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 environmental impacts associated with ther proposed actions.
Alternatives to the Proposed Action:
Since the Commission has concluded there is no measurable environmental 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 staff considered denial of the proposed actions. Denial of the application would result in no change in current environmental impacts.
The environmental impacts cf the proposed action and the alterative action are similar.
Alternative Use of Resources:
This action does not involve the use of any resources not previously considered in the Final Environmental Statement for the LGS, Units 1 and 2.
i
- Aaencies and* Persons Consulted:
In accordance with its stated policy, the staff consulted with the Pennsylvania State official regarding the environmental impact of the proposed actions. The State official had no comments.
FINDING OF NO SIGNIFICANT INPACT Based upon the environmental assessment, the Commission concludes that the proposed actions 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 actions.
For further details with respect to the proposed actions, see the j
licensee's letter dated January 14, 1994,
'pplemented by letters dated August 1, October 25, December 13, and December 22,1994 (two submittals),
which are 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 Pottstown Public Library, 500 High Street, Pottstown, PA 19464.
Dated at Rockville, Maryland, this 1st day of February 1995.
FOR THE NUCLEAR REGULATORY C0PtilSSION L &/C
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Frank Rinaldi, Acting Director Project Directorate I-2 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation
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