ML20151E445
| ML20151E445 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 03/25/1988 |
| From: | Tucker H DUKE POWER CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8804150241 | |
| Download: ML20151E445 (4) | |
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DUKE POWER GOMPANY P.O. Box 33180 CHARLOTTE, N.C. 28242 HAL B. TUCKER Tztzenows (7o4) 373-4531 March 25, 1988 U.S. Nuclear, Regulatory Commission f
- Document Control Desk Washington, D.C.
20555
Subject:
McGuire Nuclear Station Docket No. 50-369 and 50-370 Request for Relief from ASME Code Section XI Requirement Determined to be Impractical - Revision Gentlemen:
My letter of February 9,1987 (as revised via my letter dated February 16, 1987) submitted a request for relief (pursuant to 10CFR 50.55a(g) (5) (iii)) from ASME Code Section XI Hydrostatic Testing requirements for portions of modifications on the (Unit 1 and 2) nuclear service water (RN) system.
In telecons between NRC Staff reviewers and Duke Power Company, certain additional information was requested regarding Sections III (Basis For Requesting Relief) and IV (Alternate Testing) to support NRC review of the proposed relief request. This information involves the burden of isolating the affected portions of the RN sys-tem and the adequacy of proposed alternate testing.
Please -find attached the requested information.
Should there be any questions concerning this matter or if additional information is required, please advise.
Very truly yours,
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4'l sf Hal B. Tucker PBN/80/j gc Attachment
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8804150241 080325 PDR ADOCK 05000369 P
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- Document Control Desk March 25, 1988-Page 2 xc:
Dr. J. Nelson Grace, Regional Administrator U.S. Nuclear Regulatory Commaission Region II 101.Marietta St., NW, Suite 2900 Atlanta, Georgia 30323 Mr. B.R. Crowley-
' U.S. Nuclear Regulatory Connaission Region II 101 Marietta St., NP, Suite 2900 Atlanta, Georgia 30323 i
Mr. Darl Hood Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Connaission Washington, D.C.
20555 Mr. W.T. Orders NRC Resident Inspector McGuire Nuclear Station a
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ATTACHMENT 1 Duke Power Company McGuire Nuclear Station Additional Information for Sections III and IV December 17, 1986 Request for Relief from Hydrostatic Testing The following information should be included in the af fected sections of the subject relief request:
Section III - Basis for Requesting Relief C.
The modifications listed in Section A of this request will be installed during a refueling outage.
During the refueling outages, there are cer-tain periods of time each train of RN can be drained.
RN System cools the ND (Residual Heat Removal System) and the KF System (Spent Fuel Pool Cooling System) both of which are needed for the majority of the outage.
Based on a typical outage schedule, the RN supply and discharge header for either A or B Train can be drained and avcilable for work for about 10 days on Unit 2 and 6 days on Unit 1.
Unit 1 is more restricted due to the fact that the VC/YC (Control Area Ventilation System / Chilled Water System) Chillers discharge to Unit 1 discharge header only; thus when Unit I discharge header is drained, it makes VC/YC inoperable which plac-es Unit 2 in a seven-day technical specification operability constraint (per T.S. 3.7.6).
These time periods allow barely enough time to accom-plish the actual physical labor involved in implementing the modifica-tions to the RN System.
Attempting a hydro on the entire RN supply and discharge header would involve significant planning, manpower and equip-ment (high capacity, high head pump). A hydro on this large of a section of piping would add days to the outage schedule even if the pump was staged ahead of time.
Most of the t ime needed would be comprised of valve alignments to fill and vent the system.
Since isolation valves on the system are 36" butterfly valves, at hydro pressure they will likely leak by.
Even with a high capacity hydro pump there is still a good possibility of failure due to leakage past valves. To repair the 36" BIF butterfly valves would be a major undertaking since the valves are welded into place rather than flanged.
Section IV - Alternative Testing Alternative Methods of NDE for all welds listed in Section A will comply with Station Directive 3.3.4.
(See Attachment 1A) l The alternative methods specified in Station Directive 3.3.4 involve an addi-l tional MT or PT weld examination and an inservice leak inspection to be done l
to replace hydrostatic testing.
Ihe alternate testing is viewed as good as l
hydro testing for detecting veld defects to ensure safe and consistent oper-ational reliability of the system without any undue risk to the health and i
safety of the public, based on the following:
The RN System is a low temperature low pressure (135 psig design pres-sure) system.
Hydro pressure on the system would be 110% of design pres-sure or approximately 150 psig.
The additional Mr or PT examination requirement compensates for the difference in hydro pressure and inser-vice leak inspection pressure (80-90 psig).
The possibility of discov-ering additional veld defects by pressurizing to 150 psig are low to j
none.
- s, ATTACHMENT 1A
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STATION DIRECTIVE 3.3.4
. ENCLOSURE 1
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APPROVALT~). /71hDATE /0[/ f/F7 ALTERNATE METHODS OF NDE ORIG. ISSUE [6/24/81
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REVISION 2
Socket Welds futt Welds Class A PT Root
- PT-Root
- PT-Root
- RT-Final PT-Final PT-Final Class C PT-Final PT-Root
- FOR GREATER THAN 4" NPS ONLY-r PT-Final
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A MT maybe substituted for any of the above PT's.
In addition to these NDE Methods, an inservice leak test shall be performed, by Procedure MP/0/A/7650/76, if the system normally v
sees fluids. Each weld will also be hydrostatically tested during scheduled 10 year inservice inspections.
- If exemption to hydro'is requested after final welding, root pass inspection may be deleted.
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