ML20043G374

Confirms That Util Reinstated Commitment to Enhanced Leak Rate Monitoring Program on Facility,Per NRC Bulletin 88-002

ML20043G374
Person / Time
Site:	Mcguire
Issue date:	06/11/1990
From:	Tucker H DUKE POWER CO.
To:	Ebneter S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
IEB-88-002, IEB-88-2, TAC-76654, NUDOCS 9006200206
Download: ML20043G374 (2)

Text

1 il I DukeIburr Comity H,u it hw  !

. l'O ELu 33l% nce hesident l Charlotte, N C 262 Nudrar I roduction 1 GN)3734531 DUKL ' POWER I

June 11, 1990 I Hr. S. D. Ebneter, Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta St., NW, Suite 2900 Atlanta, Georgia 30329

Subject:

McGuire Nuclear Station Unit 2 NRC Bulletin No. 88-02 i Rapidly Propagating Fatigue Cracks in Steam Generator Tubes ,

Reassessment of S/G Tube, Fatigue Evaluations Analysis (TAC 76654)

Mr. D. B. Matthews's (NRC/0NRR) letter of February 27, 1989 transmitted the NRC's Safety Evaluation Report (SER) with respect to the McGuire Nuclear Station Unit 2 NRC Bulletin 88-02 (" Rapidly Propagating Fatigue Cracks in Steam Generator Tubes") response. The purpose of that bulletin was to request that Westinghouse designed nuclear power reactors with steam  :

generators having carbon steel support plates (e.g., McGuire Units 1 and 2)  !

implement actions specified therein to minimize the potential for a steam generator tube rupture event caused by a rapidly propagating fatigue crack ,

such as occurred at North Anna Unit 1 on July 15, 1987. The NRC's review '

found that our actions for McGuire Unit 2 fully resolved the issues identified in the bulletin and were acceptable (this finding was subject to ,

adoption of additional administrative controls as described in the I conclusions of the SER). This acceptance also included the option to terminate our commitment to the Enhanced Leak Rate Monitoring Program (described in our June 10 and October 6, 1988 submittals) for Unit 2, and requested we review the Leak Rate Monitoring procedures to ensure the continued offectiveness of these procedures for the timely detection, monitoring, and trending of rapidly increasing Icak rates. [A similar safety evaluation was issued for McGuire Unit 1 via Mr. Matthew's November 3, 1989 letter].

Ilowever Mr. D. S. Hood's (NRC/0NRR) May 8, 1990 letter discusses a pattern of deficiencies discovered by the NRC in the Bulletin 88-02 steam generator tube fatigue evaluations analysis performed by Westinghouse for various PWR licensees, which appear to be generic to analyses completed before November 1988 (which includes McGuire Unit 2's - ref. our August 15 and October 6, 1988 submittals). These deficiencies can Icad to non-conservative 9006200206 PDR 900611 O

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U. S. Nuclear,R:gultttry Commicalen June 11, 1990 Page 2 conclusions as to which tubes are acceptable for continued service, and accordingly Westinghouse plans to reassess these analysis and forward results to plant owners. Until the current uncertainties regarding the adequacy of McGuire Unit 2's response are resolved, the NRC has requested that we reinstate our commitment to the Enhanced Leak Rate Monitoring Program discussed in Item C.1 of the Bulletin, and submit the Westinghouse reassessment for NRC review / approval once its received.

Accordingly, this letter is to confirm that we have reinstated our commitment to the Enhanced Leak Rate Monitoring Program on McGuire Unit 2 (actually we never terminated our program even though it was allowed by the February 27th SER). Duke Power Company discussions with Westinghouse indicate-that the McGuire Unit 2 reassessment hasn't started yet, and is not scheduled to be completed until September 1990. Once Duke has received the Westinghouse reassessment and have completed our internal review of the document, it will be forwarded'to the NRC (the date of submittal is dependent upon when the reassessment is received by Duke, but is expected to be no later than by the end of October 1990).

As McGuire Unit 1 is a Category 4 plant with respect.to the analyses (ref.

the March 27, 1990 Westinghouse letter enclosed with the May 8th D. S. Ilood letter) no further actions need be taken for that unit. These matters have been discussed with Mr. D. S. Ilood in a telecon on June 7,1990. Should

. there be any questions concerning this matter or if additional information is needed, please contact Mr. P. B. Nardoci at (704) 373-7432.

Very truly yours, ,,

d( -

1' Ital B. Tucker PBN/205/lcs xc U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 ,

Mr. Darl S. Hood Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washingt on, D.C. 20555 Mr. P. K. VanDoorn NRC Resident Inspector McGuire Nuclear Station Mr. E. Shoemaker. Esq., Office of the General NRC j R. A. Wiesemann, Mgr. Regulatory & Legislative Affairs, Westinghouse Electric Corporation P.O. Box 355 Pittsburgh, PA 15230 J i