ML19225A488
| ML19225A488 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 06/06/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Millen C PUBLIC SERVICE CO. OF COLORADO |
| References | |
| NUDOCS 7907190408 | |
| Download: ML19225A488 (1) | |
Text
CEt4TPAL FILES PDR:HQ ancoq(o, UNITED ST ATES e
8
^n NUCLEAR REGULATORY COMMISSION 3.jh) c,.
IISIC REGION IV S 'f 611 RYAN PL AZA oRIVE, SUITE 1000 N-Q g
d ARLING ton, TE XAS 76012
\\ '.N+. '..
June 6, 1979 Docket No.
50-267 Public Ser W.e Company of Colorado ATTN:
Mr. C. K. Millen Senior Vice President I'. O. Box 840 Denver, Colorado 80201 Gentlemen:
.aires action by you with Enclosed is supplement IE Bulletin 79-01A.
It r-regard to power reactor facilities with an operating license except for the 11 SEP plants which are listed in Enclosure 3.
This Bulletin is also being sent for information to the 11 SEP p ants 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.
Should you have questions regarding this Bulletin or the actions required of you, please contact this office.
Sincerely, Karl V. Seyfr Director
- nclosures
1.
List of IE Bulletins Issued in the Last 12 Months
- 3. ' List of SEP Plants (11) cc:
D. W. Warembourg, Nuclear Production Manager Fort St. Vrain Nuclear Station P. O. Box 368 Platteville, Colorado 80651 L. Brey, Manager, Quality Assurance 9
7907100408 aon EU 165
UNITED STtTES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND EhTORCEMENT WASHINGTON, D.C.
20;'5 IE Bulletin No.79-01A Date:
June 6, 1979 Page 1 of 3 SUPPLEMENT NO.79-01A 'IO 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 solenoid valve in question is Catalogue W. HT-8331A45, manufactured by the Automatic Switch Company (ASCO) of Florham Paric, New Jersey. This pilot valve is used to pilot control the pneumatic valve ectuators which are installed on the containme.nt 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 maxiaum 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 ss lenoid pilot valve inoperable which would cause the associated butterfly valve to malfunction.
Further investigation at ASCO by the.v2C 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 have no plastic parts, utilize ethylene propylene or viton elastomers and have a continuously energized operating life of fear years, under normal ambient conditions up to 140 degrees F.
According to the manu-facturer, at the end of this period, the coil, manual operator (optional fea-ture) and all resilient parts must be replaced. These preventive maintqn y
instructions are specified in the installation and instrerb-are provided to the purchaser wit'. each ru.aa #
DUPLICATE _ DOCUMENT-g i
Thefinalitemsofconcernidentifieddurjapplication of Class "A," "B," or "F," so j Entire document Previously cater accident environment.
In this regard, AS'linto system ANO A
aon
,6i No of pages:
'r t. U l0 J
.3 y@l b* I
_