ML20129D130
| ML20129D130 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 07/09/1985 |
| From: | Carey J DUQUESNE LIGHT CO. |
| To: | Knighton G Office of Nuclear Reactor Regulation |
| References | |
| RTR-REGGD-01.026, RTR-REGGD-1.026 ZNRC-5-098, ZNRC-5-98, NUDOCS 8507160429 | |
| Download: ML20129D130 (2) | |
Text
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'Af 2NRC-5-098 (412) 787-5141 (412) 923-1960 Nuclear Construction Division Telecopy (412) 787-2629 Robinson Plaza, Bunding 2 Suite 210 Pittsburgh, PA 15205 July 9, 1985 United States Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:
Mr. George W. Knighton, Chief Licensing Branch 3 Of fice of Nuclear Reactor Regulation
SUBJECT:
Beaver Valley Power Station - Unit No. 2 Docket No. 50-412 Regulatory Guide 1.26 Backfit Issue
REFERENCE:
DLC letter no. 2NRC-5-056, dated March 27, 1985 Gentlemen:
In a recent meeting with Mr.
L.
S.
Rubenstein and his staf f, it was agreed that the Regulatory Guide (RG) 1.26 backfit issue would be acceptably reso lved if Duquesne Light Company (DLC) provided a reasonable discussion which explains why the piping provided as part of the emergency diesel generators is known to be functionally adequate for its purpose.
DLC agreed to addr es s the NRC's basic concern and has addres sed it in the following manner, wh ich should allow the NRC to conclude that diesel generator piping is safely designed.
As previously stated in the above reference, the diesel generator ve ndo r has stated that non-ASME piping on the BVPS-2 diesel generators is manufactured to the same standards and is of the same materials and schedules as similar diesels already accepted by the NRC.
A vendor document titled
" Description of St andard Engine PC-2 Piping" specifies pipe sizes, wall thicknesses and material types used on PC-2 engine models.
The architect /
engineer fo r BVPS-2 has used this document in evaluating piping used on a similar PC-2 engine for another project. To confirm that the vendor supplied diesel engine piping is conservatively designed, wall thicknes s, material, and system design pressure were used to calculate minimum wall thicknesses and maximum design pressure. When these calculated values were compared with actual values, safety factors ranging from 200% to 9,000% were found.
This type of cons e rvat ism is apparently typical of diesel generato r vendors in general as evidenced by the number of piping failures which occur.
The NRC Public Document Rocm has provided DLC with a list of diesel generator fail-ures fr un all licensee event reports.
None were attributable to piping failure.
8507160429 850709 PDR ADOCK 05000412 PDR A
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~Unitsd Stcteo Nuclear Riguletory Commission Mr. George W. Knighton, Chief Regulatory Guide 1.26 Backfit issue Page 2 Since it has been determined that the vendor piping description is directly applicable to BVPS-2, the evaluation and conclusions described above are also directly applicable. This provides DLC with adequate assurance of a funct ionally conservat ive piping design.
Since the St anda rd Review Plan recognizes that similarity to previously approved designs is an acceptable basis for acceptance by the staf f, we believe this discussion addresses your concern.
DUQUESNE LIGHT COMPANY By
/
J. / (/Carey Vit!e President GLB/wja Attachment cc:
Mr. H. Denton Mr. V. Nerses Mr. T. Novak Mr.'L. S. Rubenstein Mr. B. K. Singh Mr. G. Walton COMMONWEALTH OF PENNSYLVANIA )
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COUNTY OF BEAVER
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d day of
, /[ [ [, before me, On this e a
Notary Public in and for said CdemonGealth and County, personally appeared J.
J.
Carey, who being duly sworn, deposed and said that (1) he is Vice Pres ident of Duquesne Light, (2) he is duly authorized to execute and file the foregoing Submittal on behalf of said Company, and (3) the statements set forth in the Submittal are true and correct to the best of his knowledge.
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Notary Public SNEllA 5. IATIORE. NOTARY PUBUC SHIPPisGP9tf 80e0. B(AVER COUNTY BY C0BulS$105 EIPla(5 SEPT.16.1985 Womber. Penact vais Association of Notaries i
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