ML19246B974
| ML19246B974 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 06/06/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Bryan J UNION ELECTRIC CO. |
| References | |
| NUDOCS 7907190295 | |
| Download: ML19246B974 (1) | |
Text
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-PDR' pa meC UNITED STATES f
NUCLEAR REGULATORY COMMISSION
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REGloN 111
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E GLEN ELLYN, ILLINol$ 50137 S,, e...a JUN 6 1979 Docket No. 50-483 Docket No. 50-486 Union Electric Company ATTN:
Mr. John K. Bryan Vice President - Nuclear P. O. Box 149 St. Louis, MO 63166 Gentlemen:
Enclosed is supplement IE Bulletin No.79-01A.
It requires action by you with regard to power reactor facilities with an operating license except for the 11 SEP plants wbith 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 facilities or the 11 SEP plants.
Snould you have questions regarding this Bulletin or the actions required of you, please contact this office.
Sincerely,
\\
A (-
M James G. Keppler
- j. Director
Enclosure:
IE Bulletin No.79-01A rc w/ encl:
Mr. W. H. Weber, Manager, NSIC Nuclear Construction TIC Central Files Region I & IV Director, NRR/DPM "s.
K. Drey Director, !GR/DCR Hon. C. J. Frass, Chairman PDR Missouri Public Service Local PDR Commission 07.1@g g 343 2/8
U.S. NUCLEAR REGULATORY COMMISSION 0FFICE OF INSPECTION AND ENFORCEMENT
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REGION III June 6, 1979 IE Bulletin No. 79-OlA SUPPLEMEhi No.79-01A TO IE BUI.LETIN 79 ENVIRONMIh'IAL QUALIFICATION OF CLASS 1E EQUIPMEhT (DEFICIENCIES IN THE ENVIRONMENTAL QUALIFICATION OF ASCO SOLENOID VALVES)
Description of Circumstances:
Recently, a noncompliance report under 10 CFR Part 21 was receivel by the NRC from the Henry Pratt Ccmpany, manufacturer of butterfly valves which are installed in the irimary 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 repor: discusses the use of an unqualified solenoid valve for c 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 Co=pany (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 :nade of acetal plastic material.
The acetal disc holder asse=bly and bottom plug in the pilot valve assembly are stated by ASCO a have a u ximum service 11:1t of 400,000 Rad integrated dosage and 200 degrees F te=perature. According to ASCO, exposure of these acetal plastic parts to specified =aximu= 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 se vice limit of 7,000,000 Rad integrated dosage and ISO 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 ethylane propylene or viton elastomers and have a continuously energized operatit.g life of four years, under nor=al anbient conditions up to 140 degrees F.
According to the manu-facturer, at tLe end of this period, the cail, manual operator (optional tea-ture) and all r'esilient parts must be replaced. These preventive msintenance instructions are specified in the installation and instruction bulletins which are provided to the purchaser with each shipment of solenoid valves.
The final ite=s of concern identified during this investigation deals,vich A 1 application of Class "A",
"B", or "F", solencic' cod e: 'M eca^#
1l accident environment.
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