ML20028G897
| ML20028G897 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 08/27/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20028G890 | List: |
| References | |
| NUDOCS 9009050372 | |
| Download: ML20028G897 (3) | |
Text
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UNITE 3 STATES '
NUCLEAR REGULATORY COMMISSION l
5 W ASHINGTON, D. C. 30666
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.163 TO FACILITY OPERATING LICENSF NO. NPF-1 PORTLAND GENERAL ELECTRIC COMPANY THE CITY OF EUGENE. OREGON PACIFIC POWER AND LIGHT COMPANY TROJAN NUCLEAR PLANT D_0 Crit NO. 50-344
1.0 INTRODUCTION
By letter dated August 12, 1988, as clarified by letter of August 16, 1988, the Portland General Electric Company (PGE) submitted License Change Application (LCA) 169 to the Trojan Technical Specifications (TS). The roposed TS changes are intended to insure Emergency Core Cooling System p(ECCS) check valve integrity by revising the surveillance requirements of Table 3.4.6-1, which is associated with the TS Section 3/4.4.6.2 and relates to leakage from the reactor coolant system pressure isolation valves. The changed Technical Specifications will require that when leakage tests are performed using a test differential pressure lower than t
the functional maximum, observed leakage rates will be adjusted from the actual test differential pressure in a prescribed manner.
The changes proposed by the August 12 and 16, 1988, submitta'1s were encompassed within the notice 19,1988(53FR40999)publishedintheFederalRegist October 2.0 DISCUSSION Reactor Coolant System (RCS) pressure is isolated from the Safety Injection System (SIS) by two in-series check valves for each RCS loop (A-D). When failure of one valve in a pair could go undetected due to system configuration, >eriodic testing is required to verify valve integrity and reduce t1e overall risk of an intersystem Loss-of-Coolant
' Accident (LOCA). Test requirements are specified in Trojan Technical Specification Surveillance Requirement 4.4.6.2.2 and Periodic Operating Test (POT) 2-4, "ECCS Pressure Boundary and Accumulator Check Valve Leakage Inservice Test."
3.; EVALUATION The licensee states that the postulated failure condition for these in-service check valves is that the lowest leakage valve is presumed to fail and that the highest leakage valve is exposed to its maximum differential pressure. Thus the pressure difference to which either of l-9009050372 900827 PDR ADOCK 05000344 P
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. j these in-series check valves can be exposed may be substantially than the differential pressure used for the surveillance testing. greater At higher differential pressures, the leakage rates can be expected to be higher.
Therefore, while leakage rates measured using appropriate test differential pressures may be within the TS Table 3.4.6-1 limits, leakage through the same leakage path with actual (higher) differential pressures can be higher and might exceed the limits imposed by the Technical I
Specifications.
Since the flow rate through a fixed flow resistance is proportional to the square root of the pressure difference across the resistance, multiplying the measured leakage flow rate by the square root of the ratio of the function maximum pressure difference to the test differential pressure gives a more realistic estimate of the expected flow rate than the measured flow rate itself.
We, therefore, conclude that the licensee's proposed change to the Trojan Technical Specification is acceptable.
t 4.0 CONTACT WITH STATE OFFICIAL j
The NRC staff has notified the Oregon Department of Energy of the proposed t
issuance of this amendment along with the proposed determination of no significant hazards consideration. No comments were received.
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5.0 ENVIRONMENTAL CONSIDERATION
This amendment involves a change a requirement with res)ect to in the t
installation or use of a facility component located wit 11n the restricted area as defined in 10 CFR Part 20. The staff has determined that the amendment involves no significant increase in the amounts, and no signifi-cant change in the types, of any effluents that may be released offsite, r
I and that there is no significant increase in individual or cumulative occupational radiation exsosure. The Commission has previously published a proposed finding that t1e amendment involves no significant hazards consideration and there has been no public comment on such finding.
Accordingly, the amendment meets the eligibility criteria for categorical exclusionsetforthin10CFR51.22(c)(9).
Pursuant to 10 CFR 51.22(b),
no environmental impact statement or environmental assess-ment need be prepared in ccnnection with the issuance of the amendment.
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6.0 CONCLUSION
We have concluded, based on the considerations discussed above that (1) there is reasonable assurance that the health and safet ofthepub1Icwillnotbe endangered by operation in the proposed manner, (y) such activities will be 2
u conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
PRINCIPAL CONTRIBUTOR:
J. Bradfute Dated: August 27, 1990
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