ML20141F057

Provides Suppl 1 to Inservice Insp Program Relief Request I2R-22 from ASME Section XI Requirements,As Requested by NRC During 970528 Telcon

ML20141F057
Person / Time
Site:	Wolf Creek
Issue date:	06/24/1997
From:	Muench R WOLF CREEK NUCLEAR OPERATING CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
ET-97-0063, ET-97-63, NUDOCS 9707010333
Download: ML20141F057 (3)

Text

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W$LF CREEK NUCLEAR OPERATING CORPORATION Richard A. Muench Vice President Engineering June 24, 1997 ET 97-0063

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U.'S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station Pl-137 Washington, D. C. 20555 l

l Reference Letter ET 97-0040, dated April 24, 1997, from R. A. Muench, WCNOC, to USNRC l

Subject:

Docket No. 50-482: Supplement 1 to Inservice Inspection Program Relief Request I2R-22 I

Gentlemen: I The Reference transmitted Wolf Creek Nuclear Operating Corporation's (WCNOC)

Inservice - Inspection Program Relief Request I2R-22, which requested relief from ASME Section XI requirements for the Wolf Creek Generating Station Inservice Inspection (ISI) Program in accordance with the provisions of 1 10 CFR 50. 55a (g) (5) (iii) .  !

On May 28, 1997, WCNOC personnel participated in a telephone conversation with I NRC personnel concerning Relief Request I2R-22. During the telephone conversation, NRC personnel requested additional information to facilitate ,

their review of the Reference. The attachment to this letter provides l Supplement 1 to I2R-22, which contains the information requested by the NRC  ;

during the May 28, 1997, telephone conversation, l If you should have any questions regarding this submittal, please contact me at (316) 364-8831, extension 4034, or Mr. Richard D. Flannigan at extension 4500.

Very truly yours, 9707010333 970624

' PDR ADOCK 05000482 Richa d A. Muench G PDR l

RAM /jad l

Attachmt l

cc: W. D. Johnson (NRC), w/a E. W. Trschoff(NRC), w/a J. F. hingwald (NRC), w/a J. C. Stone (NRC), w/a f

' (,) .L U v'nn98 i P.O. Box 411/ Burlington, KS 66839 / Phone: (316) 364-8831 An Equal Opportunity Employer M F HCVET

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• l Attachment to ET 97-0063 i

,,- Page 1 of 2 l Relief Request I2R-22 Supplement 1 l Second Interval Inservice Inspection Program Relief Request I2R-22 was submitted to request the use of ASME Section XI paragraph IWA-5244, " Buried i Components" in the 1995 Edition with 1995 Addenda as an alternative to the j same paragraph in the 1989 Edition. Wolf Creek Nuclear Operating Corporation l (WCNOC) is committed to the 1989 Edition. As part of the basis for relief, i two examples were presented to demonstrate the need and acceptability of the requested alternative. The remaining buried components at Wolf Creek Generating Station (WCGS) are testable in accordance with the 1989 Edition; however, the request to use the 1995 Edition with 1995 Addenda was not intended to be limited to the examples provided. The intent is to maintain a program that is committed to the same Edition and Addenda for all buried component examinations. This will allow for a consistent approach for all buried component examinations rather than permitting one set of examinations to be performed under one set of requirements and another group to be performed to different requirements. The testing methodologies for those configurations not requiring the use of the 1995 Edition with the 1995 Addenda do not change when updating from the 1989 Edition. Thus, for application at WCGS, the use of the 1995 addenda for all buried component examinations fully l meet the requirements of the 1989 Edition. l Following the initial submittal, additional information was requested regarding how WCNOC plans to apply the 1995 Edition with 1995 Addenda IWA-5244 requirements for the examples provided. Included below is additional information for each of the two examples.

1) For the underground supply piping of the Essential Service Water (ESW)

System, WCGS intends to perform a pressure test in accordance with the isolable system provisions, subparagraph IWA-524 4 (b) (1) . A rate of pressure loss from the test volume would be quantified by the measurement of a mass loss out of identified boundary valves and compared with the rate of makeup to the system. The acceptable difference in system makeup, minus identified boundary leakage, is based on the maximum losses allowable from i the Ultimate Heat Sink (UHS) for 30 day shutdown (the UHS is the safety related source of suction for the ESW System and contains a volume of water to provide shutdown cooling for a minimum of 30 days). The allowable loss I from the UHS can vary depending on sedimentation levels; however, the I minimum volume (maximum sedimentation) for the UHS currently provides for j an allowable leak rate of 140 gpm. I l

I Information regarding leak location methods was also requested. Paragraph IWA-5244 contains provisions for buried components where a VT-2 visual examination cannot be performed. It is important to note that the method of leak location is not prescribed by the Code for the buried components and is therefore left up to the owner for determination. ASME Section XI only requires corrective measures, i.e., locating and repairing / replacing the pipe, when the owner specified acceptance criteria has been exceeded. If the acceptance criteria is exceeded, various methods could be used to locate leakage sources. In addition to the pressure test, the subject portions of ESW piping are typically under a static pressure from the non-safety related Service Water System; therefore, leakage exceeding the 140 gpm described above would become noticeable above ground over time and may provide a general location for the leak. Also there are a few locations where portions of the piping are accessible through removal of a spool

piece in an underground vault. Removal of the spool piece would provide l access for visual examination of the inside diameter. This is one logical means of locating the leakage from the piping, other methods such as l excavation may also be used.

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( Attachment to ET 97-0063

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l Page 2 of 2

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2. ,The b.yried components in the Emergency Fuel Oil Transfer System include the supply piping (transfer pump discharge) from the buried storage tank and the- recirculation / overflow piping which provides a gravity drain back to the storage tank. The transfer pump is submerged within the tank and

( therefore, flow is not measurable at that end of the pipe; however, flow l can be measured by in-plant equipment as the piping exits'the ground and i enters the Emergency Diesel Generator Building. This flow rate represents l the total flow to the Emergency Diesel Engine. Fuel oil that is not consumed by the engine returns back to the storage tank. The current j Inservice Testing Program at WCGS requires this pump to be tested on a l quarterly frequency. The nonisolable provisions of subparagraph IWA-5244 (b) (2) would be satisfied by 'the Inservice Testing of the transfer pump, which would identify if flow in the buried components was impaired.

l Again, while these are the two cases at WCGS where the testing methodology of the 1995 Edition with 1995 Addenda would allow for a more meaningful examination, the use of the 1995 Edition and Addenda for the entire buried component population is requested since the program for the balance of the systems will meet the requirements of the 1989 Edition.

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