ML19225A493
| ML19225A493 | |
| Person / Time | |
|---|---|
| Site: | Humboldt Bay |
| 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 7907190417 | |
| Download: ML19225A493 (1) | |
Text
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qh UNITED STATES
[lL E \\*) 7. cg[ 'g NUCLEAR REGULATORY COMMISSION I
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""Y.//. I REGION V
$ $d 1990 N. CAL'FORNI A BOULEVARD
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o SUITE 202, WALNUT CREEK PLAZ A WALNUT CHEEK, CALIFORNI A 94596 June 6,1979 Docket No. 50-133 Pacific Gas and Electric Company 77 Beale Street San Francisco, California 94106 Attention: f tr. Philip A. Crane, Jr.
Assistant General Counsei Gentlemen:
Enclosed is supplement IE Bulletin 79-Ol A.
It requires action by you with regard to po'. 'r 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.
No action or written response is required for construction permit facilitier or the 11 SEP plants.
Should you have questions regarding this Bulletin or the actions required of you, please contact this office.
Sincerely,
~
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. 11.- ngelken -/
Director t
Enclosuee:
IE Bulletin No.79-01A cc w/ enclosure:
W. Barr, PG&E W. A. Raymond, PG&E E. Weeks, PG&r Humboldt Bay
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UNITED STATES NUCLEAR P,EGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHIf1GTON, D.C.
20555 June 6, 1979 IE Bulletin No.79-01A SUPPLEMEllT NO.79-01A TO IE BULLETIN 79 ENVIRONMENTAL QUALIFICATION OF CLASS 1E EQUIPMENT (DEFICIENCIES IN THE ENVIRONMENTAL QUALIFICATION OF ASCO SOLEHOID 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 tne primary containment at the Three Mile Island Unit 2 Nuclear Station. These butterfly 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 val' a 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 dosage 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 "N" 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 solencia operated pilot valves (ASCO Catalogue No. NP-1) which have no plastic parts, utilize ethylene propylene or viton elastomers and have a continuously energized
- operating life of four years, under normal embient condition'; up to 140 degrees F.
According to the manu-facturer, at the end of this period, the wil, manual operator (optional fea-ture) and all resilient parts must be replaced. These preventive maintenance instructions are specified in the installation and instruction bulletins which are provided to the purchaser with o$rMme'aR*p*hc m n c4 DUPLICATE DOCUMENT The final items of concern identif1 g application of Class "A",
"B',', or "j! Entire document previously entered accident environment.
In this rega. 2 into system under:
A N O 3 'l U ? D R O l 7 5 42.0 i$ 3 J
No. of pages:
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