ML20055G998

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Responds to NRC Re Generic Implications & Resolution of Control Element Assembly Failure at Plant on 900607.New Control Element Assemblies Ordered.Addl Response Will Be Submitted at Least 60 Days Prior to Restart
ML20055G998
Person / Time
Site: Calvert Cliffs  Constellation icon.png
Issue date: 07/20/1990
From: Creel G
BALTIMORE GAS & ELECTRIC CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
TAC-66457, NUDOCS 9007250033
Download: ML20055G998 (2)


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  • A B ALTIMORE
  • OAS AND ELECTRIC CHARLES CENTER
  • P.O. BOX 1475
  • BALTIMORE, MARYLAND 21203-1475 OtoRoc C CRtcL Vect PatstotNi Nvettam rNERGY (300 #40 446B '

July 20,1990 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION: Document Control Desk

SUBJECT:

Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 Response to Request for Additional Irformation Regarding Control Element Assembly (CEA)- Failure at Mai.ag yankee (TAC 66457)

REFERENCE:

(a) Letter from Mr. R. A. Ca:n (NRC) to. Mr. G. C. Creel (BG&E),

dated July 6 1990, Generic . Implications and Resolution of CEA Failure at 1. aine'.~ Yankee : for. _Calvert Cliffs, Unit Nos. 1 - and 2, TAC 66457 4

Gentlemen:

i On June 7, 1990, while . conducting' functional testing $f the' control element assemblies (CEA)at Maine Yankee, it - was discovered that one CEA could not be fully inserted into the core. Subsequent investigation concluded ' that it is most likely that-irradiation assisted stress corrosion' cracking led to' CEA failure. The failure 3

mechanism is only applicable to the older Combustion Engineering CEA - (14 x 14) design.

Calvert Cliffs Unit I has no old (14 - x 14) design CEAs installed and there are no plans to use them . in the future. Thus, the problem is not applicable : to Unit -1.

Calvert Cliffs Unit 2 currently has 68 CEAs of the 14 x 14 design installed.

l' Reference (a) notes that Baltimore Gas and . Electric (BG&E) Company intends to implement an Action Program to address the. continued use of the CEAs currently j installed in Unit 2. Additionally, Reference -(a) requests additional information

!- regarding the' Action Program.

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9007250033 900720 fDR ADOCK 05000317 i PDC  !

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Document Control Desk

, Jb,1y 20,1990

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.The current plans for Unit 2 are to eventually replace all 68 CEAs. New C';W have  !

been ordered from the vendor and may be received as ently as the end of Oct:,?.,,. 199.).

Should the vendor delivery schedule not support the Unit 2 restart and should analysis support safe continued use of the old CEAs, we will respond to the Reference (a) questions at least 60 days prior to the scheduled Unit 2 restart.

It is our understanding that delaying our response to - the questions is acceptable to the NRC Staff given that Unit 2 is currently in a refueling outage, and that there is a r;ssibility that the old style CEAs may not be reused. Unit 2's restart is ,

currently scheduled for late 1990. i Should you have any further questions regarding this matter, we will be pleased to discuss them with you.

Very truly yours, M+

G. C. Creel ice President - Nuclear Energy GCC/JMO/ dim cc: D. A. Brune, Esquire J. E. Silberg, Esquire R. A.Capra, NRC D. G. Mcdonald, Jr., NRC T. T. Martin, NRC L. E. Nicholson, NRC R. I. McLean, DNR i

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