ML20151K662

Submits Addl Info Re Analyses Required by IE Bulletin 79-14, Seismic Analysis for As-Built Safety-Related Piping Sys. Errors in Weight & Center of Gravity for Small Bore Copes- Vulcan Valves Discussed

ML20151K662
Person / Time
Site:	Prairie Island
Issue date:	07/21/1988
From:	Larson C NORTHERN STATES POWER CO.
To:	Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
IEB-79-14, NUDOCS 8808030240
Download: ML20151K662 (7)

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.' OuD Northem States Power Company 414 N(o net Mall Minneapohs, Minnesota 55401 Telephone (612) 330 5500 July 21, 1988 NRC IE Bulletin 79-14 Mr A Bert Davis, Administrator Region III U S Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137 PRAIRIE ISIAND NUCLEAR GENERATING PIANT DOCKET NOS. 50 282 LICENSE NOS. DPR-42 50-306 DPR-60 Additional Response to IE Bulletin 79-14 i Seismic Analysis for As-Built Safety Related Piping Systems l

Reference:

(a) NRC Region III Inspection Report 50-282/306/88009(DRS) dated June 30, 1988 The purpose of this letter is to provide additional information re-lated to analyses required by NRC IE Bulletin 79 14, "Scismic Analysis for As-Built Safety Related Piping Systems." This information is related to the recent discovery of errors in the weight and center of gravity specified for small bore Copes-Vulcan valves installed at the Prairie Island Nuclear Generating Plant. Background information related to this issue is contained in Reference (a).

During a review of work originally performed to meet the requirements of NRC IE Bulletin 79-14, discrepancies were found in the weights and centers of gravity specified in drawing revisions issued by Copes-Vulcan for three valve models supplied to the Prairie Island plant.

Later revisions of the detailed drawings ("L" drawings) for these valves specified increased weights and centers of gravity than those specified on the cutline ("S" drawings) used in the original calcula-tions.

The "S" drawings have typically shown both the valve weight and center of gravity, while the "L" drawings have typically shown just the valve weight. These valves were supplied to Prairie Island by the Westing-house Electric Corporation. See the attached table for a complete listing of Copes.u ulcan valves used at the plant.

In investigating this matter with Westinghouse and Copes Vulcan, we have Icarned that the revised "L" drawings contain accurate informa-tion, even though this information conflicts with the original "S" (b \

drawing data.

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A Bert Davis Nodhem States Power Company July 21, 1988 Page 2 Because the original piping analysis was based on the lower weights and centers of gravity for these valves, Northern States Power Company has requested the Prairie Island architect-engineer (Fluor Daniel) to perform an evaluction of all small bore Copes Vulcan valves used in safety related applications in the plant. Evaluations completed at this time by Fluor Daniel include the three worst cases and provide justification for continued plant operation until all analyses can be completed. The Fluor Daniel analyses envelope all analytical cases for Copes-Vulcan valves using conservative valve weights and centers of gravity.

Of the 15 models of Copes Vulcan small bore valves in use at Prairie Island, and potentially affected by this problem, only one type is in use at other Westinghouse designed plants. This valve model (ID Nn.

IIA 56RE) was supplied to both the Prairie Island and Surry plants.

Westinghouse reports that Virginia Power Corporation requested them to recalculate the center of gravity and weight for this valve, therefore the correct values are being used at Surry for this valve model.

An additional valve model (ID No. 3IA58RGP), is within the Westing-house piping analysis scope. Westinghouse has determined that an appropriate valve weight and center of gravity was used in piping analyses that included this valve model.

Based on this information, it appears that incorrect valve weights and centers of gravity for these particular valve models is currently a problem only at Prairie Island.

Correct valve weights and centers of gravity have now been confirmed by Westinghouse (Attachment 1). Fluor Daniel is now completing analy-ses of the remaining potentially affected piping systems. We antici-pate completion of these analyses prior to the Unit No. 1 outage later this summer. During the outage, any modifications required to restore original conservative design margins will be completed in Unit 1.

Similar modifications, if required, will be completed in Unit 2 during the next refueling outage early next year.

Please contact us if you have any questions related to this issue or if you require ditional information.

C E Lars n Vice Pre de dNuclearGeneration c: J A Gavula, NRC Region III Sr Resident Inspector, NRC NRR Sr Project Manager, NRC G Charnoff Attachments

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,. Atthchment (1)

A Bart Divis July'21.-1988 Westinghouse # of NSP Valve ID Size L Print Rev. # S Print Rev. # Valves See Note 1 3/4-IA58-RE 3/4l L-137857* 2 S-129989 6 2 3

3/4-IA58-RE 3/4 L-140209* 2 S-129989 6 8 1-RA42-DD 1 L-137820 2 S-133149 6 2 1-RA36-RDS 1 L-137914 3 S 133149 6 2 1-IA38-RES 1 L-138930 3 S-133150 9 2 1-IA56-RE' 1 L-137918* 2 S-133150 9 4 1-IA56-RES 1 L-137919 2 S-133150 9 4 1-RA58-RD 1 L-140975 2 S-133149 6 2

.1-IA58-RE 1 L-137968 2 S-133150 9 6

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2-IA58-DG 2 L-143864 0 S-130032 9 4-2-IA56-RE 2 L-138023 2 S-133269 3 2 2-IA58-RG 2 L-144157 0 S-130032 9 6 2-IA58-RE 2 L-138049 7 S-133269 3 4 2-2RA42-RD 2 L-141003 A S-133151 7 3 3-IA58-RGP 2 L-143844 1 S-131642 5 4

• These "L" drawings have since been revised to indicate a change in center of gravity and/or weight. The associated "S" drawing does not reflect any change in center of gravity or weight.

NOTES: 1. Revision numbers lis'ted are the latest revisions at NSP.

2. Letter from Copes Vulcan to Barry Dickerson, FD, indicating a possible discrepancy of weight and center of gravity.  !

3. Same valve and operator as L-140209 but on different drawing L-137857. -

4. Per phone conversation with Copes Vulcan representative verifies that PI print has incorrect center of gravity.

5. These valve analyses have correct center of gravity and weight

, per phone conversation with Westinghouse representative, Lonnie Benson, on 6/24/88. Documented on letter to NSP from Westing- <

house on 6/28/88 and again per phone conversation with Lonnie ,

Benson on 7/1/88, i

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Attechment (2) fm c kq a'A Bart Davis 4 July 21, 1988 g40 L 4 h0k n nso 1988 8 amsrsus Westinghouse Power Systems s/ce7 8"'

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• Mr. J. E. Goldsmith NSP-88-176 Prairie Island Nuclear Generating Station Northern States Power Company July 8, 1988 1717 Wakonade Drive East Welch, MN 55089 Ref: 1) NSP ltr. TS-88 096, 6/21/88, Goldsmith to Benson

2) H ltr. NSP-80-23, 4/30/80, Northern States Power Company Prairie Island Nuclear Generating Station Prairie Island Valve Weiahts and Centers of Gravity

Dear Mr. Goldsmith:

Westinghouse has contacted Copes-Vulcan and obtained correct weights and centers of gravity for the valves listed in reference 1. Corrected weights and centers of gravity are provided in the attachment to this letter. Please note in most cases the weights and centers of gravity are different from those shown on the "L" and "S" drawings on file at Prairie Island and Westinghouse.

Based on Westinghouse's review, it has been determined that none of the valves identified in your letter were utilized in any Westinghouse piping analyses with the exception of Valve I.D. 3IA58RGP.

On Valve I.D. 3IA58RGP, Westinghouse previously requested a corrected weight and center of gravity from Copes Vulcan, so it could verify its piping analysis per action identified in Reference 2 to the NRC. This was completed and Westinghouse has reverified the correct weight (341 lb.) and C.G. (21.8 in.)

was utilized in the Prairie Island analysis. Subsequent to this review, NSP purchased replacement Copes Vulcan valves and the system was again rechecked per NSP request and verified acceptable. In this case, it was reconciled that the new weight (350 lb) and C.G. (22.7 in.) had a negligible effect on the system analysis.

Regarding the "S" and "L" drawings and revision levels, Copes Vulcan has i indicated that the "S" drawings are typical for a family of valve ID's, whereas the "L" drawings are specific to each ID. Therefore, the "L" drawing should be used for valve information. Based on this transmittal, it is recommended that NSP update the "L" drawings indicated in the attachment to reflect the corrected weights and centers of gravity.

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NSP-88-176 Mr. J. E. Goldsmith July 8, 1988 Concerning your question on whether this is a 10CFR21 issue, based on Westinghouse piping analysis scope review (Reference 2), it was concluded valve weight and center of gravity changes did not create any safety concerns. .It is understood that NSP has Fluor Daniel assisting in review of B0P piping analysis scope in response to IE Bulletin 79-14. Therefore, determination of whether there are any 10CFR21 issues related to BOP piping analysis would be dependent on their evaluation.

Should you have any questions concerning this subject, please let me know.

Very truly yours, v ^^?

L. R. Benson, Manager Prairie Island Project U.S. Nuclear Projects

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f-i NSP-88-176 Mr. J. E. Goldsmith July 8, 1988 i

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Attachment to NSP-88-176 COPES-VULCAN VALVE WEIGHT AND CENTER OF GRAVITY Valve I.D. Drawina Corrected Weiaht and C. G.'

Weight (ib.) C.G. (in.)

3/4IA58RE(1)(3) L-137857 240 19-1/4 3/41A58RE (1)(3) L-140209 240 19-1/4 1RA42DD(1) L-137820 116 14-13/16 1RA36RDS (1) L-137914 120 14-1/8 11A38RES (1) L-138930 206 18-13/16 IIA 56RE (2) L-137918 184 20-1/2 11A56RES (1) L-137919 184 20-1/2 1RA58RD (1) L-140975 141 12-3/4 IIA 58RE (1) L-137968 225 19-3/8 2IA580G (1) L-143864 291 20-5/8 2IA56RE (1) L-138023 228 19.7 2IA58RG (1) L-144157 334 21-7/8 2IA58RE(1) L-138049 264 17-7/16 2RA42RD (1) L-141003 140 13-9/16 31A58RGP(4) L-143844 341 21.83 .

(1) Review indicates valve only supplied to Prairie Island by Westinghouse (2) Review indicates valve only supplied to Prairie Island and Surry by Westinghouse (3) Different drawing due to Cy of valve (4) Yalve in Westinghouse piping analysis scope

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