ML19330B570

Confirms Verbal Notification Re Tech Spec 1.3 Violation. Rated Thermal Power Exceeded 2,700 Mwt for Three to Four Days.Caused by Undetected Leak in Steam Generator Blowdown Recovery Heat Exchanger.Investigation Continues

ML19330B570
Person / Time
Site:	Calvert Cliffs
Issue date:	08/04/1980
From:	Russell L BALTIMORE GAS & ELECTRIC CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
NUDOCS 8008050050
Download: ML19330B570 (1)

Text

_- . . _. _ _ _ __ _ -______ _ ____________ _

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TO: Mr. B. H. Grier Director .

Region I, U.S.N.R.C.

FRCH: L. B. Russell, Plant Superintendent .

Calvert Cliffs Nuclear Power Plant ,

!

SUBJECT:

Docket Nos. 50-317/50-318; Violation of Technical Specification 1.3 LER Nos. 80-35 (U-1), 80-34 (U-2)  ;

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This is to confinn our verbal notification to Mr. W. Troskoski and Mr.

E. McCabe, of your offica, as required by Technical Specification 6.9.1.8 (Prompt Notification with written follow-up) of a violation of Technical .

Specification 1.3 exceeding rated themal pcwer for both Units 1 and 2.

The event and cause descriptions are as folicws.

• On July 27, 1980, it was confirmed that both Units 1 and 2 had exceeded rated thermal power of 2700 MWth when the unics were operating at 1005 power for approximately three to four days as a result of an undetected '

leak in a steam generator blowdown recovery heat exchanger resulting in an erroneous input to the core calorimetric calculation. On July 26,1980, Unit one's all steam generator blowdown recovery heat excnanger was dis-covered to nave an approximately 200 gpa leak and on July 27 Unit two's s21 steam generator blowdown recovery heat exchanger was discovered to '

have an approximately 75 gpa leak frcan the unit's ccodensata system to the

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respective steam generator blowdcwn recovery system. Steam generator blowdown ficw rate is a parameter used in tne calculation for core calorimetric power. The erroneously high steam generator blcwdcwn flow

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rate c used an error in the nonconservative direction of approximately 24 IWth for Unit 1 and 8 Mith for Unit 2 whicn allcwed the Operator's to -

oxceed rated thermal power of 2700 MWth. After the steam generator ,

blowdown recovery heat exchangers were confinned to have failed tubes, the defective heat exchangers were immediately isolated and placed out of service. Unit l*s #11 staam ganarator blowdown recovery heat excnanger 4

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was placed out of servica at 1530 on 7/26, and Unit 2's #21 steam generator blowdown recovery heat exchanger was placed out of service at 1315 on 7/27 After the respective heat exchangers were placed out of servica the blowdown flow indicator was verified to be in calibration and correct blowdown flow was entered into the computar calorimetric calculation.

An investigation as to when the leaks began is continuing and a more accurate estimate as to their inspection, as well as a description of the correctivo action will be contained in the follow-up report. l 135Eum L. B. Russell @(o .

Plant Superintendent 'i -

1 Calvert Cliffs Nuclear Power Plant LBR/SMD/bjt l mg m T Y

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