ML20059D803
| ML20059D803 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 08/31/1990 |
| From: | Cross J PORTLAND GENERAL ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-88-008, IEB-88-8, NUDOCS 9009070191 | |
| Download: ML20059D803 (3) | |
Text
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NUMM James E. Cross Vice President, Nuclear i
i August 31, 1990 Trojan Nuclear Plant Docket 50-344 1,1 cense NPF-1 U.S. Nuclear Regulatory Commission
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Attn Document Control Desk Washington DC 20555
Dear Sirs:
f Nuclear Regulatory Commission Bulletin (WRCB) 88-08, j
" Thermal Stresses in Pining Connected to Reactor Coolant Systems" Dy letter dated 0:tober 4, 1988. Tortland General Electric Company (PCE) responded to NRCB 88-08.
By letter dated September 27, 1989, PCE provided an update on the actions being taken in response to the Bulletin. The attachment to thio letter provides current status of implementation of our program to provide continuing assurance that adverce temperature distributions are not occurring in unisolabic piping connected to the Reactor Coolant System.
Sincerely,
[
Attaciunent c:
Mr. John B. Martin Regional Administrator, Region V U.S. Nuclear Regulatory Commission Mr. David Stewart-Smith State of Oregon Department of Energy
(
Mr. R C. Barr NRC Resident Inspector Trojan Nuclear Plant 9009070191 900831 gDR ADOCK 05000344 PDC
'f 121 SW Salmon St. Portland, OR 97204
/
)
503/464 8897
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Trojan Nuclear plant Document Control Desk Docket 50-344 August 31, 1990
' License NPF-1 Attachment page 1 of 2 PORTLAND GENERAL ELECTRIC COMPANY (pCE) UPDATE ON ACTIONS FOR NUCLEAR REGULATORY COMMISSION BULLETIN (NRCB) 88-08,
" THERMAL STRESSES IN PIPING CONNECTED-TO REACTOR 700LANT SYSTEMS" By letter dated October 4, 1988, pCE responded to NRCB 88-08.
The response reported identification of pipin6 lines connocted to the Reactor
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Coolant System (RCS) which may have the potential for thermal stratification or eyeling, partial completion of nondestructive examinations of critical piping locations, and intentions for performins additional analysis of thermal monitoring data.
By letter dated September 27, 1989, PGE provided an update on the actions j
being taken in response to the Bulletin.
The update reported completion of the nondestructive examinations, with no cracks found.
It also ret ~ctad that analysis of initial thermal monitoring dato indicated there was leaka ? Into the high-head safety injection 'ines and that a bypass u
line around the boron injection tank (BIT) was capped to eliminate One of the potent'~*
Sakage paths into the header.
Subsequent efforts to provide ass::
ice that adverse temperature distributions are not occur ing ars summarized below.
Analysis of thermal monitoring data taken on the high-head safety injection lines indicates that additional leakage into the header was occurring past two RCS first-off check velves, 8900A and 8900D, and was possibly occurring past the BIT isolation valves, M08801A and M08801D.
Inspection of these four valves during the 1990 Refueling Outage revealed that degradation existed which may have resulted in the leak 6ge past the valves. Maintenance was performed to correct unacceptable degradation.
The impact on piping integrity of thet", transients observed on these lines was shown through analysis to b.
neeptable.
Analysis of thermal monitoring data taken on the RCS normal and alternate charging lines indicates that unacceptable leakage through valves associated with these lines is not occurring.
Thermal' transients observed on these lines are consistent with the design transients and are not attributed to valve leakage.
Analysis of thermal monitoring data Laken on the pressurizer auxiliary spray line indicates that unacceptable leakage through valves associated with this line is not occurring.
Until a permanent program is impicmented to provide continuing assurance that adverse temperature distributions are not occurring in unisolable piping connected to the RCS, PCE will continue with an interim approach of obtaining thermal monitoring data twice per operating cycle and taking appropriate corrective actions based on analysis of the data.
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_ 1 hrojan Etclear Plant Document Control Desk-Docket 50-344
' August 31, 1990 i
License NPF-1 Attachment i
Page 2 of 2
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J developing a permanent program, PGE la participating in interutility j
programs to identify long-term solutions to +h. problams identified in
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Status of our long-term solution will be provided by March 31,'1993.
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