ML19225A497
| ML19225A497 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 06/06/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Crane P PACIFIC GAS & ELECTRIC CO. |
| References | |
| NUDOCS 7907190423 | |
| Download: ML19225A497 (1) | |
Text
lQ fa Recoq'o UNITED STATES
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['y tf' [j NUCLEAR REGULATORY COMMISSION C
REGION V re, J.p m,,ir// c D -
Ff 1990 N. CALIFORNI A BOULEV ARD s ' f5 U
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SUITE 202. V/ALNUT CREEK PLAZA t
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V/ALNUT CR E EK, CALIFORNIA 94596 June 6,1979 Docket flos. 50-275 50-323 Pacific Gas and Electric Company 77 Beale Street San Francisco, California 94106 Attention: Mr. Philip A. Crane, Jr.
Assistant General Counsel Gentlemen:
Enclosed is supplement IE Bulletin 79-01A.
It requires action by you with regard to power reactor facilities with an operating license except for the 11 SEP plants which are listed in Enclosure 2.
This Bulletin is also being sent for information to the 11 SEP plants and all power reactor facilities with a construction permit.
tio action or written response is required for construction permit facilities or the 11 SEP plants.
Should you have questions regarding this Bulletin or the actions required of you, please contact this office.
Sinu. ely,
/
V l Engelken/ g {ll y
.H Director *
Enclosure:
IE Bulletin flo. 79-OlA cc w/ enclosure:
W. A. Raymond, PG&E J. D. Worthington, PGSE R. Ramsay, PG&E, Diablo Canyon
(
S/d 7n0739 cab 3
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF IflSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 June 6, 1979 IE Bulletin No.79-01A SUPPLEMENT NO.79-01A TO IE BULLETIN 79 ENVIRONMENTAL QUALIFICATION OF CLASS 1E EQUIPMENT (DEFICIENCIES IN THE E!4VIRONMENTAL QUALIFICATION OF ASCO SOLEN 0ID VALVES)
Description of Circumstances:
Recently, a noncompliance report under 10 CFR Part 21 was received by the NRC from the Henry Pratt Company, manufacturer of butterfly valves which are installed in the prim:ry containment at the Three Mile Island Unit 2 Nuclear Station. These butter.'ly valves are used for purge and exhaust purposes and are required to operate during accident conditions.
The report discusses the use of an unqualified solenoid valve for a safety-related valve function which requires operation under accident conditions.
The solenoid valve in question is Catalogue No. HT-8331A45, manufactured by the Automatic Switch Company (ASCO) of Florham Park, New Jersey. This pilot valve is used to pilot control the pneumatic valve actuators which are installed on the containment ventila-tion butterfly valves at this facility.
The deficiency in these solenoid valves identified in the Part 21 Report concerns the parts made of acetal plastic material.
The acetal disc holder assembly and bottom plug in the pilot valve assembly are stated by ASCO to have a maximum service limit of 400,000 Rad integrated dcsage and 200 degrees F temperature. According to ASCO, exposure of these acetal plastic parts to specified maximum environmental conditions may render the solenoid pilot valve inoperable which would cause the associated butterfly valve to malfunction.
Further investigation at ASCO by the NRC staff has revealed that the valve seals in most ASCO solenoid valves contain Buna "it" elastomer material, which reportedly has a maximum service limit of 7,000,000 Rad integrated dosage and 180 degrees F temperature. The investigation further revealed that ASCO has available a line of qualified solenoid operated pilot valves (ASCO Catalogue No. NP-1) which have no plastic parts, utilize ethylene prcpylene or viton elastomers and have a continuously energized' operating life of four years, under normal embient conditions up to 140 degrees F.
According to the manu-facturer, at the end of t.his period, the coil, manual operator (optional fea-ture) and all resilient parts must be rephrpd.
These preventive maintenance instructions are specified in the install Hns which yDUPLICATE R CUMENT
~
are provided to the purchaser with each s i
Entire document previous 1y The final items of concern identified dui into system under:
ntered application of Class "A", "B", or "F" so-accident environment.
In this regard, A ANO_) f 0 }020( l No. Of pages. 420 211 t ~ [ ~~-%--%. ,}}