ML17252A246

Letter Submitting Reportable Occurrence Number 050-249/1976-23 in Accordance with Technical Specifications, Section 6.6.B

ML17252A246
Person / Time
Site:	Dresden
Issue date:	11/04/1976
From:	Stephenson B Commonwealth Edison Co
To:	James Keppler NRC/RGN-III
References
BBS Ltr. #76-775
Download: ML17252A246 (3)

Text

.**. Comrnonv.h Edison

• Dresde,1 Nuclear Power Station R.R. #i Morris, Illinois 60450 Telephone 815/942-2920 BBS Ltr. #76-775 November 4, 1976 Mr. James Keppler, Regional Director Directorate of Operations

-.Region III U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137 Enclosed please find Reportable Occurrence report number 50-249/1976-23.

This report is being submitted to your office in accordance with the Dresden Nuclear Station Techriical Section 6.6.B. A n n . : . *1Y) _/) .. * -I-. .. . B. Stephensori

• tation Superintendent. . Dresden Nuclear Power Station BBS :jo Enclosure cc: Director of Inspection

& *Enforcement . Direct'or of Management Information

& Program Control File/NRC

. LICENSEE EVd\JT REPOR. *. -. . * .. ' CONTROL BLOCK: I ' I *.1 1. I I (PLEASE PRll'JT ALL REQUIRED INFORMATION)

' 1 6 .* '*. LICENSEE * < NAME .@El I I I L. ID IR I s 13 I 7 8 9 ' 14 CATEGORY REPORT TYPE. LICENSE NUMBER 10101-10101010101-10101 15 25 REPORT SOURCE OOCl\ET NUM6ER

• LICENSE TYPE 1!1111111111 26 ' 30 EVENT TYPE 10131 '31 ' 32' EVENT* DATE REPORT DATE lof1 I coN1 I I I 7 8 57 58' llJ 59 LLl 60 61 68 11 IOIOl?l71(,l

.*II II 1014171(, L 69 74 75 80 EVENT DESCRIPTION . (filg].lD!JRtAJ.G-REFUELING-OUTAGE LDC.AL l.t:Ak-:-RATE TESTING; *LPC/ PRtrnARV I 7* 8' 9 . ' 80. lol31 ltSO.L..ATION'.

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• TYPE DESCRIPTION lo Io JO I : .

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• A)ff' 7 8 9 10 80 PUBLICITY l:illl 7 8 ADDITIONAL FACTOfiS (1JUJ /v*>0' 7 89 80 EEi 7 89 BC NAME: __ R;._A_/i_V_])_o_'-_*

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PHONE: £xT. d...G 5

, . . ... .. ,. '* .. ;; . . ; ** EVENT DESCRIPTION (Continued) the as-found leakage of 61.0 SCFH was attributed entirely to leakage through check valve 1501-25B.

A second leak test using valves 1501-26B, i501-22B, and 1001-SB as boundaries yielded a leakage rate of 4.2 SCFH: Since .the second test volume included the volume of the previous test, total through-leakage for the penetration was well under the Tech Spec limit. A similar valve on Unit-2 failed 16cal testing in early 1975. (50-249/1976-23)

CAUSE DESCRIPTION. (Continued)

The valve was disassembled, the seat was lapped, and the packing and _Flexitallic gasket were replaced.

Leak-rate testing of the reassembled valve was satisfactory.

In 1975, a test/drain line was installed on this penetration which permitted leak-rate testing of check valve 3-1501-25B for the first time since unit oper-ation began. Since this valve has performed*

satisfactorily over a period of . several years, testing of this vaLve on an approximately annual basis should permit timely identification of a recurring problem.

• Valve 3-15.0l-25B is a 16-inch tilting disc check valve, manufactured by.Atwood and Morrill Company, Inc.