ML20127K859
| ML20127K859 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 01/21/1993 |
| From: | Wharton L Office of Nuclear Reactor Regulation |
| To: | Schnell D UNION ELECTRIC CO. |
| References | |
| REF-GTECI-070, REF-GTECI-094, REF-GTECI-NI, TASK-070, TASK-094, TASK-70, TASK-94, TASK-OR GL-90-06, GL-90-6, TAC-M82627, NUDOCS 9301260243 | |
| Download: ML20127K859 (4) | |
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UNITED STATES
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January 21, 1993 Docket No.
50-483 Mr. Donald F. Schnell Senior Vice President - Nuclear Union Electric Company Post Office Box 149 St. Louis,' Missouri 63166
Dear Mr. Schnell:
SUBJECT:
CALLAWAY NUCLEAR PLANT - STAFF REVIEW OF GENERIC LETTER 90-06
" RESOLUTION OF GENERIC ISSUE 70, ' POWER-OPERATED RELIEF VALVE AND BLOCK VALVE ~ RELIABILITY,' AND GENERIC ISSUE 94, ' ADDITIONAL LOW-TEMPERATURE OVERPRESSURE PROTECTION FOR LIGHT-WATER REACTORS,'
4 PURSUANT TO 10 CFR 50.54(f)" (TAC NO. M82627)
By letters dated December 18, 1990, and supplemented December 4 1991 and i
March 11, 1992, the Union Electric Company (the licensee) respon,ded to Generic Letter (GL) 90-06.
The generic letter represented the technical resolution of two generic issues and included plant backfits which were cost-Justified safety enhancements. Generic Issue 70. included upgrades in quality require-ments -inservice testing requirements, and modified technical specifications for all pressurized water facilities that incorporate Wwer-operated relieve valves (PORV) and block valves in their design. The li: tended purpose was to enhance the overall reliability of the PORVs and block valves so that they could better perform the safety functions identified in the generic letter.
Generic Issue 94 included modified technical specifications for all Westinghouse and Combustion Engineering facilities to reduce the allowed outage time for an inoperable low-temperature overpressure protection (LTOP) channel and thus reduce the probability of overpressurization events during i
shutdown conditions.
The staff has reviewed your submittal and finds that you have modified selected portions of the generic letter.
It is the staff's position that a regulatory analysis has been performed in accordance with 10 CFR 50.109(a)(3) and 50.109(c) which justifies the backfit.
Therefore, absent-any information that demonstrates that your facility is not bounded by the regulatory analysis that accompanied the generic letter, you are requested to resubmit a response -
that is in keeping with the intent of the generic letter.
The specif,ic areas of concern-are as follows.
9301260243 930121 PDR. ADOCK 05000483 l'
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Mr. Donald F. Schnell
-2 January 21, 1993
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The staff position requires the 18-month PORV stroke test to be performed during Mode 3 (HOT STANDBY) or Mode 4 (HOT SHUTDOWN) and in all cases prior to establishing conditions where the PORVs are used for low-temperature over-pressure protection.
Your submittal did not adequately meet this staff
)osition. The staff is not accepting Mode 5 (COLD SHUTDOWN) testing simply secause it is allowable by th? ASME Code or that the NRC-approved IST program includes Mode 5 for this particular test.
The requirement to perform stroke tests of the PORVs during Modes 3 or 4 is a new position for some licensees. The basis for this position lies in the uncertainty introduced by stroke testing the PORVs at lesser system temper ature conditions and then expecting them to perform adequately at operatin system conditions.
If this recommendation is not adopted, a sound technic 1 basis should be provided (e.g., that such testing cannot be performed without significant system modifications or that the intent of such testing is accom-plished by some other means). We note that one licensee has proposed the option to bench test the PORVs. This would be acceptable, provided the tests are performed at conditions simulating Mode 3 or 4 conditions or greater and provided the proper reinsta11ation of the PORVs and controls is verified.
In another case, the staff accepted an argument from a licensee that the physical distance between the PORV and the pressurizer maintained the same pressurizer temperature (and therefore pressure) in Modes 3, 4, or 5 such that there is no difference from the valve's perspective of testing in different Modes.
In this case, the PORVs would be primarily influenced by the ambient room conditions.
Additionally, the GL required that PORVs be stroke tested in all cases prior to establishing conditions where the PORVs are used for low-temperature over-pressure protection. This could be interpreted to mean that PORVs should be stroke tested during every shutdown and again during every startup. However, the inclusion of the PORVs in the IST program requires the valves be tested no more frequently than every 3 months (unless valve maintenance is performed) to demonstrate operability.
In summary, the staff maintains its position that the PORVs should be stroke tested during Modes 3 or 4 in order to verify the capability to function in an l
environment more representative of operating conditions.- In your revised-i response, discuss how PORY stroke testing provides assurances that-the PORVs will perform all necessary safety functions adequately at the required system operating conditions.
You are requested to respond within 60 days following receipt of this letter.
If you would like to further discuss these issues prior to your resubmittal, please feel free to contact me.
. J. C.
January 21, 1993 n,
r.' d F. Schnell [
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' ",..weion requested by ti.is letter is within the scope of the overall t
Nesh:c
,timated in Generic letter 90-06 for the resolution of GI 70 and
! 94, which was a maximum of 320 person-hours per licensee response.
This equest is covered by Office of Management and Budget Clearance Number J150-0011, which expires May 31, 1994.
l.
Sincerely, ORIGINAL SIGNED !!Y:
L. Raynard Wharton, Project Manager Project Directorate III-3 Division of Reactor Projects III/lV/V i
Office of Nuclear Reactor Regulation cc:
See next page DISTRIBUTION Docket File NRC & Local PDRs PDill-3 Reading JRoe JZwolinski JHannon PXreutzer LRWharton OGC ACRS (10)
PDill-3 Gray Region Ill, DRP 4
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OfflCIAL RECORD DOCUMENT NAME:
G:\\CALLAWAY\\ CAL 82627.GLT
1 I
Mr. D. F. Schnell Callaway Plant j
Union Electric Company Unit No. I f
i j
cc:
Cermak fletcher Associates Mr. Bart D. Withers i
18225 Flower Hill Way #A President and Chief Gaithersburg, Maryland 20879-5334 Executive Officer Wolf Creek Nuclear Operating Corporation l
Gerald Charnoff, Esq.
P.O. Box 411 Thomas A. Baxter, Esq.
Burlington, Kansas. 66839 l
Shaw, Pittman, Potts & Trowbridge j
2300 N. Street, N.W.
Mr. Dan I. Bolef, President i
Washington, D.C.
20037 Kay Drey, Representative
- Board of-Directors Coalition i
Mr. S. E. Sampson for the Environment l
Supervising Engineer, 6267 Delmar Boulevard j
Site Licensing University City, Missouri 65130 Union Electric company i
Post Office Box 620-j Fulton, Missouri 65251 l
U.S. Nuclear Regulatory Commission l
Resident inspectors Office RR#1 Steedman, Missouri. 65077 i
Mr. Alan C. Passwater, Manager Licensing and Fuels i
Union Electric Company-Post Office Box 149 l
St. Louis, Missouri 63166 i
i Manager - Electric Department Missouri Public Service Commission 301 W. High Post Office Box 360 Jefferson City, Missouri 65102 4
g Regional Administrator U.S. NRC, Region III i
799 Roosevelt Road
- Glen Ellyn. Illinois.60137 Mr. Ronald A. Kucera, Deputy Director 4
Department of Natural Resources l
P.O. Box 176 --
Jef ferson City,- Missouri 65102 4
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