ML19294A574
| ML19294A574 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 12/19/1978 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Dewitt R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| NUDOCS 7812280056 | |
| Download: ML19294A574 (1) | |
Text
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UNITED STATES f
, t NUC L E A R REGULA10RY COMMISSION fI A'
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G LE N E L L Y N, ILLifeOf S 60137
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Docket No. 50-155 Consumers Power Company ATTN:
Mr. R. B. DeWitt Manager of Nuclear Plant Operations 212 West Michigan Avenue Jackson, MI 49201 Gentlemen:
The enclosed IE Bulletin No. 78-14 is forwarded to you for action.
A written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely, kW4 James G. Keppler Director
Enclosures:
1.
List of IE Bulletins Issued in 1978 cc w/encls:
Mr. C. J. Hartman, Plant Superintendent Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR NSIC TIC Ronald Callen, Michigan Public
' Service Commission Anthony Roisman, Esq.,
Attorney 781228crog
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U.S. NUCLEAR REGUIATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT REGION III Dece:ber 19, 1975 IE Bulletin No. 75-14 DEIERIORATION OF EL*NA-N COMPONENTS IN ASCO SOLENDIDS Description of Circumstances:
Tellowing a reactor scra: at the Monticelle Nuclear Fever Statier or July 27, 1975, one control rod was deterrined to have a slow scra insertion ti=e.
Vnile r:easuring the average control red scra insertier tires (as required by Technical Specifications), the same control red failed te scrat.
Subsequent investf ation revea2ed that a Euna-N disc E
in the scra: pilot valve solenoid core asse:bly had fractured. Stall pieces of the Buna-N =aterial vedged between the core asser.bly and the valve pilot body. This prevented proper =ovecent of the cere asse:bly (plunger), and thus prevented the valve fro: properly venting control air fro: the scra: valves. A sirilar event occurred durinE scrat testing on June 5, 1975. On both occasions the control rud failed te scra during control rod surveillance testing. In these instances, had a scra occurred during nor=al operation of the reactor, the affected rods would have inserted by action of the backup scrat solenedd valves.
The reactor was p; aced in cold shutdown on July 25, 1975. All of the scra pilot se:encid valves and scra: backup valves were disasseriled and inspected.
Six additional fractured Bana-N discs were found, all in scra pilot se2enoid valves. Northern States Fever Co pany replaced the plunger Buna-N discs in all 2l.2 scrat pilot valves and the 2 backup scra: valves.
In addition to the Montice31o failures, siri]ar events were recent1;;
reported fro: the Eig Rock Point and Pilgrit facilities. At Eig Rock Point, two failures were experienced in October while at PdI rit one E
failure was found in July and two in Dece:ber. All of these failures were encountered during surveillance testing.
General EJectric had previously issued Service Infor atien Letters, SIL 126 (March 31, 1975) and SIL 128 Kevisien 1 (January 3C,1976),
addressing the deterioration through natural aging of Buna-N co:penents im CTG ser _
gNws-A,, m&, %ggg, _.., ma int enance pr ogra: be in scrat pf20t valv
~. tuna-N discs DUPLICATE DOCUMENT Entire document previously entered into syste1 under:
-71/22402.30 ANO No. of a es:
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