ML18219C197

Response to IE Circular No. 76-06 & Provide Description of Program for Assuring Continued Integrity of Safety-Related Piping System, as Requested

ML18219C197
Person / Time
Site:	Cook
Issue date:	12/29/1976
From:	Tillinghast J American Electric Power Service Corp
To:	James Keppler NRC/RGN-III
References
IEC-76-006
Download: ML18219C197 (6)

Text

0 0 AMERlCAN ELECTRIC POWER Service Corporation 2 Broadtottp, iVno York, X Y. 10004 (212) 422.4800 ZOHII TILIJKCiIIhST Vice Chairman Enginrrring anci Conttncation December 29, 1976 Donald C. Cook Nucl'ear Plant Unit No. 1 Docket No. 50-315 DPR No. 58 Nr. Z. G. Eeppler, Regional Directox U.S. Nuclear Regulatory Commission Office of Xnspeccion and, Enforcement Region XXX 799 Roosevelt Road Glen Ellyn, Illinois 60137

Dear Nr. Kepplex:

This letter is in response to your letter of November 26, 1976, which was received on Novemoer 29, 1976, and, which transmitted to us XE Cixcular No. 76-06 entitled; "Stxess Corrosion Cxacks in Stagnant, Low Pressure Stainless Piping Containing Boric Acid Solution at*PNR's." You requested that we pxovide a description of our program for assuring continued integrity of safety-related piping systems which are not frequently flushed, or which contain non-flowing liquids, and for'exforming hydro tatic testing in accordance with AS1~tE Code Section XX Rules for ceri ain active systems. You also suggested that we consider volumetric examination of certain circumferential pipe welds by non-destructive techniques which are generally in accordance with Appendix X of Section ZX'.

You requested a repori= describing our program and a schedule fox these inspections within 30 days after receipt of your letter, with a summary report of the examination 60 days after completion of the inspections'.

Jfg 3 ]gy7 Our Katiott,'8200tIt Year ~g976.. Our Company's70th Fear

0 > 'e Mr . O'. G . Eeppl ember 29, 1976 Since we received your letter, we have been working on a program which (a) defines those portions of safety-related piping systems which come under the criter'a,of not being frecp-ently flushed, or containing non-flowing liquids, (b) con-siders hydrostatic testing for safety-related piping, (c) attempts to define the appropriate non-destructive examination techni'ques, and (d) develops a schedule for the inspections which can be

.made at the Donald C. Cook Nuclear Plant Unit l.

With regard to the concern about piping systems "not frecpxently flushed, " the Residual Heat Removal system at the Cook. Nuclear Plant has been in service. six times s'ince startup in January, 1975.

Relative to the incidents that occurred on specific piping systems at other nuclear units as noted in Circular 76-06, in the course of our review, we noted that the high pressure safety injection piping from the charging pumps is flushed regularly up to the containment isolation valves. Between the isolation valves and the reactor coolant loop, the piping has bean Slushed six times since startup in January, 1975. The suction piping on the safety injection pumps is flushed every month as required by our technical specifications.

On December 23, 1976 we took Unit 1 out, of service for its first refueling outage. Many of the people wno are involved in defining and implementing the program outlined in XE Circular 76-06 have been occupied with preparing for the outage and are, now participating in it. We expect the Unit outage to last about 8 weeks. While we have gotten a good start in defining the major piping systems coming under the "not frequently flushed" category, we need more time to have this reviewed at American Electric Power Service Corporation, by the plant staff, and possibly by outside in-ser~ce inspection contractors. We therefore request an extension "of the date for pxoviding the information requested 3.n items 1 and 2 of your letter to April 15, 1977.

Xn the. interim we will continue the surveillance xequimements of the Donald C. Cook Nuclear Plant Technical Spem.<ications regarding leak detection and operability of cafe~-related equipment together with our'xesponse to FSAR Ques'~on 6-6 rega'rding in-service inspection of other fluid sys'tems.

I

M' Mr. J. G. Eeppler 3 December 29, 1976 We appreciate your informing us of the several incident's of through-wall cracking which occurred in other nuclear power plants. Let me assure you that we are aware of those incidents and intend to ta'ke the appropriate measures to make sure that we have-'a program for inspection, detection, and correction of those problems should they

'ccur at the Donald C. Cook Nuclear Plant.

Very truly yours, Js

• 1g i Vic6 Chairma ngineering and Co truction JT 'mam cc: Gerald Charnoff R.C. Callen P.W. Steketee R. Walsh R.J. Vollen R.S. Hunter R.W. Jurgensen Bridgman Dr. Ernst Volgenau, Director Office of Inspection and .Enforcement