ML20085M954
| ML20085M954 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 06/19/1995 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20085M952 | List: |
| References | |
| NUDOCS 9506290418 | |
| Download: ML20085M954 (3) | |
Text
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,.,,4 UNITED STATES p*
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NUCLEAR REGULATORY COMMISSION f
WASHINGTON, D.C. 20066 4001
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION g
RELATED TO AMENDMENT NOS. 207 AND 209 TO FACILITY OPERATING 4
LICENSE NOS. DPR-44 and DPR-56 PECO ENERGY COMPANY PUBLIC SERVICE ELECTRIC AND GAS COMPAM DELMARVA POWER AND LIGHT COMPANY ATLANTIC CITY ELECTRIC COMPANY PEACH BOTTOM ATOMIC POWER STATION. UNIT NOS. 2 AND 3 DOCKET NOS. 50-277 AND 50-278
1.0 INTRODUCTION
By letter dated March 22, 1995, PECOEnergyCompany(thelicensee) submitted $a request for changes to the Peach Bottom Atomic Power Station, Unit Nos. 2 and 3, Technical Specifications (TS). The requested changes would reduce the local leak rate test (LLRT) hold time specified in the TS Tables 3.7.2 through 3.7.4 from one hour to 20 minutes.
2.0 EVALUATION Section 4.7 of the existing Peach Bottom TS specifies the requirements for Primary Containment, including equipment operability and surveillance requirements. TS 4.7.A.2.f states:
Local leak rate tests (LLRT's) shall be performed on the primary containment testable penetrations and isolation valves in accordance with Tables 3.7.2, 3.7.3 & 3.7.4 at a pressure of 49.1 psig (except for the main steam isolation valves, see below) per 10 CFR 50 Appendix J requirements.
Tables 3.7.2f.3.7.3 and 3.7.4 list individually all of the primary containment i
testable penetrations and testable isolation valves.
Footnotes for these tables provide? additional detail on the testing requirements for these penetrations.- Note 1 (pl88 of the TS) states that the minimum test duration for all valves and penetrations listed is one hour.
In the March 22, 1995 application, the licensee proposed to revise the footnote to read:
Minimum test hold time duration for all valves and penetrations listed is 20 minutes after stabilization.
9506290418 950619 PDR ADOCK 05000277 P
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t Local leak rate tests are typically conducted by isolating the affected component and exposing the component to a test source of pressure. The test pressure is applied to the component and component leakage is determined either by pressure decay methods or flow rate methods.
For pressure decay methods, the test pressure source is isolated from the component after initial pressurization and the rate at which pressure decays is measured over a period of time (referred to as the hold time). The rate of pressure decay is used to determine the leakage rate of the component.
In the second method, the component remains connected to a test source for the duration of the test.
Flow into the component is assumed to compensate for component leakage.
During the hold time, the actual flow rate into the component is measured with flow measuring instrumentation which thus allows direct quantification of the leak rate.
Both test methods allow a period of time after initial pressurization prior to commencement of the hold time to allow for stabilization.
This period allows for transient dynamic and temperature effects to stabilize, thus allowing the measurements obtained during the hold time to be representative of the leak tightness of the component.
The licensee stated that, based on a review of previous Peach Bottom LLRT test data, it concluded that no significant changes in leakage rates occur during' the one hour hold time after leakage stabilization is achieved.
Therefore, PECO concluded that decreasing the hold time from one hour to 20 minutes does not adversely affect the results of the LLRT.
The licensee noted that decreasing the LLRT hold time will decrease the occupational dose received by the individuals performing the test.
Appendix J to 10 CFR 50 specifies primary containment leak testing requirements for water cooled reactors. Appendix J does not specify local leak rate test methodologies to a level of detail that addresses hold times and stabilization.
liowever, Section 6.4.3 of ANSI /ANS 56.8-1994, " Containment System Leakage Testing Requirements," states:
Pressure decay tests should have a test duration of not less than 15 minutes after stable conditions have been attained. A flow makeup test should be used if a pressure decay test cannot be performed for at leasO15 minutes.
No minimum test duration shall be required for a make-up: flow test; however, test data shall be obtained during stable conditions.
The staff reviewed the licensee's proposed changes. The staff has previously reviewed the LLRT guidance in Section 6.4.3 of ANSI /ANS 56.8-1994 and finds this guidance acceptable.
The staff concludes that the proposed changes are more conservative than the guidance in Section 6.4.3 of ANSI /ANS-56.8-1994.
Thus the staff finds that the proposed changes to the Peach Bottom TS will not
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adversely affect the results of LLRTs at Peach Bottom and are therefore, acceptable.
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3.0 STATE CONSULTATION
In accordance with the Comission's regulations, the Pennsylvania State official was notif,ied of the proposed issuance of the amendments. The State official had no coments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as. defined in 10 CFR Part 20.
The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure.
The Comission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public coment on such finding (60 FR 24913). Accordingly, the amendments 7
meet the eligibility criteria for categorical exclusion set forth in 10 CFR i 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
5.0 CONCLUSION
The Comission has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Comission's regulations, and (3) the issuance of the amendments will not be inimical to the comon defense and security or to the health and safety of the public.
Principal Contributor:
J. Shea Date: June 19, 1995 k,.