ML20064D672
| ML20064D672 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 12/30/1982 |
| From: | Dixon O SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8301040718 | |
| Download: ML20064D672 (3) | |
Text
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SOUTH CAROLINA ELECTRIC & GAS COMPANY POST OFFICE 764 COLUMaiA. SOUTH CAROUNA 29218
- o. W. DixO N,JR.
VICE PRESIDENT December 30, 1982 uuCot.. o,Enarion.
Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission i
Washington, D.C.
20555
Subject:
Virgil C. Summer Nuclear Station i
Docket No. 50/395 l
Operating License No. NPF-12 Independent Seismic Design Verification
Dear Mr. Denton:
In March of 1982, South Carolina Electric and Gas Company (SCE&G) was requested to perform an Independent Seismic Design Verification of a portion of the Virgil C.
Summer Nuclear Station required for safe shutdown of the facility.
Accordingly, in letters to the NRC dated April 8, 1982, and April 12, 1982, SCE&G proposed and implemented an Independent Design Verification of the Turbine Driven portion of the Emergency Feedwater System.
This program consisted of three l
phases; (1) a design control audit, (2) a field walkdown to l
confirm the as built configuration, and (3) an independent confirmatory stress analysis and evaluation.
Stone and Webster Engineering Corporation (SWEC) was contracted to perform this verification effort.
SWEC completed this effort and submitted the final report to the NRC on October 15, 1982.
This letter satisfies License Condition 2.C(6) as a final report to the NRC delineating the final resolution of the actions taken to satisfy the recommendations of the Independent Design Verification conducted by SWEC.
The design control audit portion of the SWEC review determined that although implementation of the design control program was adequate, the application of damping factors to pipe stress analyses required clarification to preclude future misunderstanding.
SCE&G responded in our letter to the NRC dated November 1, 1982, that clarification of damping factor l
information would be included in the next revision of " Piping l
l Engineering Section-Nuclear Criteria for Piping Stress Analysis and Pipe Support Design" to preclude the possibility of a future misunderstanding of damping factor information.
This next i
revision is now scheduled for January 18, 1983.
So l
o 8301040718 821230 PDR ADOCK 05000395 P
7 PDR
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i I
Mr. Harold R.
Denton December 30, 1982 Page #2 SWEC also recommended that a procedure be formalized which governs the preparation and distribution of an index for project specifications.
Our response letter to SWEC dated October 15, 1982, stated that although it was not audited by SWEC, GAI Design Control Procedure DCP 3.20 was utilized for this purpose.
SWEC made a recommendation in the design control audit that the extent of incomplete documentation in the analytical packages be determined.
SCE&G's letter to the NRC dated November 1, 1982, stated that our audit program had previously identified this problem as informalities, or inconsistencies, in documentation.
As discussed in our October 12, 1982, and November 1, 1982 letters, SCE&G and Gilbert Associates, Inc.,
(GAI) are in the process of reviewing these analytical packages.
To date, none of these inconsistencies have been found to be safety significant.
Based on our current schedule, reviews of the analytical packages and the determination of the extent of the inconsistences will be finished by January 1, 1983.
It is expected that final clean-up of the documentation will be completed by March 31, 1983.
The field walkdown portion of the design verification effort performed by SWEC resulted in three areas of concern:
(1) gap requirements on box supports, (2) skewed support directions, and (3) clearance requirements of penetration P-IB-I-041.
Gap requirements on box supports and misidentification of skewed support directions resulted in reviews by SCE&G.
These reviews have been completed and were discussed in our responses to SWEC.
A separate penetration review program was undertaken for safety related piping to ensure proper clearances and all discrepancies found were corrected.
As discussed in our letter of October 12, 1982, to SWEC, the clearance requirement of penetration P-IB-I-041 was addressed by this program and accepted.
As a result of the independent confirmatory stress analysis, SWEC made several recommendations in their final report.
SCE&G submitted two letters to SWEC dated October 12, 1982, and October 15, 1982, in response to those recommendations.
These two letters were included as attachments to the final SWEC report submitted the NRC.
SWEC recommended reviews by SCE&G of computer analyzed problems for the correct application of Seismic Response Spectra, Seismic Anchor Movements and Jet Impingement.
As discussed in our responses to S%EC noted above, these reviews were performed and completed satisfactorily.
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.I Mr. Harold R.
Denton December 30, 1982 Page #3 Based on the results of the Independent Design Verification Program, the recommendations made by SWEC, and the follow-up actions taken by SCE&G, SWEC concluded in their final report l
that "the piping seismic design of the Virgil C.
Summer Nuclear Station meets the desiga criteria and is adequate to withstand the specified seismic events."
SCE&G concurs in that conclusion.
If you require additional information, please advise.
Ver tru y your w
O.
W.
Dixon, Jr.
NEC:OWD:lkh cc:
V.
C.
Summer G.
H.
Fischer H.
N.
Cyrus T.
C.
Nichols, Jr.
O.
W.
Dixon, Jr.
M.
B.
Whitaker, Jr.
J.
P.
O'Reilly H.
T.
Babb l
D.
A.
Nau man C.
L. Ligon (NSRC)
W.
A.
Williams, Jr.
R.
B.
Clary O.
S.
Bradham A.
R.
Koon M.
N.
Browne G.
J.
Braddick i
J.
L.
Skolds J.
B.
Knotts, Jr.
B.
A.
Bursey NPCF File i
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