ML19225A478
| ML19225A478 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 06/06/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Eric Turner HOUSTON LIGHTING & POWER CO. |
| References | |
| NUDOCS 7907190395 | |
| Download: ML19225A478 (1) | |
Text
7 E. C R R E C(,g
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Io, UNITE D STATES y y 3,. cg[ ^g NUCLEAR REGULATORY COMMISSION S yyV/.. #
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REGION IV k .h[o t4 611 RYAN PLAZA DRIVE, SUITE 1000 AR LINGToN, T E X AS 7G012
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June 6, 1979 In Reply Refer To:
RIV Docket Nos. 50-498/IE Bulletin No.79-01A 50-499/IE Bulletin No.79-01A Houston Lighting & Power Company ATTN:
Mr. E. A. Turner, Vice President Power Plant Construction and T2chnical Services Post Office Box 1700 Houston, Texas 77001 Gentlemen:
Enclosed is supp' ament IE Bulletin 79-01A.
It requires action by you with regard to power reactor facilities with an operating license except for the 11 SC? plants which are listed in Enclosure 3.
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 f acilities or the 11 SEP plants.
Should you have questions regarding this Bulletin or the actions required of you, please contact this office.
Sincerely, f
k A'
Karl V.
eyfrif Director
Enclosures:
1.
List of IE Bulletins Issued in the Last 12 Months 3.
List of SEP Plants (11) 4
/GO 147 7mm som
UNITED STATES NUCLEAR REGULATORY COMMISSION-0FFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Bulletin No.79-01A Date: June 6, 1979 Page 1 of 3 SUPPLEMENT NO.79-01A TO IE BULLETIN 79 ENVIRONMENTAL QUALIFICATION OF CLASS 1E EQUIPMENT (DEFICIENCIES IN THE ENVIRONMENTAL 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 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 soleroid 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 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 solenoid operated pilot valves (ASCO Catalogue No. NP-1) which havu 'o plastic parts, utilize ethylene propylene or viton elastomers and have a continuously energized operating life of four years, under normal ambient conditions up to 140 degrees F.
According to the manu-facturer, at the end of this period, tb77e^#1 -9enal nnerator_(optional _fea-2" ture) and all resilient parts must be i jDUPLICATE DOCUMENT
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instructions are specified in the insti are provided to the purchaser with eacl; nt.
The final items of concern identified ;p re document previously entered ystem under:
applicationofClass"A,""B,"or"F,"l;
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accident environment.
In this regard,[,
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