ML19225A373
| ML19225A373 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 06/06/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Boyer V PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| References | |
| NUDOCS 7907190098 | |
| Download: ML19225A373 (1) | |
Text
p 'e::q YN
'o, UNITED STATES
'4
- /' i NUCLEAR REGULATORY COMMISSION 5 k kif,h j REGION i C, AMb 5
631 PARK AVENUE 0,
[
KING OF PRUSSIA PENNSYLVANI A 19.:06 1
+....
June 6, 1979 Docket Nos. 50-352 50-353 Philadelphia Electric Company ATTN: Mr. V. S. Boyer Vice President Engineering and Research 2301 Market Street Philadelphia, PA 19101 Gentlemen:
Enclosed is supplement IE Bulletin 79-01 A.
It requires action by you with regard to power reactor facility (ies) with an operating license except for the 11 SEP (Systematic Evaluation Program) 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 these two categories of facilities.
Should you have questions regarding this Bulletin or the actions required of you, please contact this office.
Sincerely, dA Boyce H. Grier
' Director
Enclosures:
1.
List of IE Bulletins Issued in Last T
.ve Months 3.
List of SEP Plants (11) 335 101 79071go gg
ENCLOSURE 1 UNITED STATES NUCLEAR REGULATORY COMMISSION 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 CLAS31E 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 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 ventilation butterfly valves at this facility.
The deficiency in these solenoid valves identified in the Part 21 Report concerns
'he 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 have no plastic parts, utilize ethylene propylene 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 manufacturer, at the end of this period, the coil, manual operator (optional feuture) and all resilient parts must be replaced. These preventive maintenance instructions are specified in the installation and instruction bulletins which are provided_tdDe nurchasar, Wh.--nubt -
of solenoid valves.
The final items of concern identifu, j DUPLICATE DOCUMENT
'~
application of Class "A", "B", or "F Entire document previously entered accident environment.
In this regar,into system under:
79 070A0/ 73 nNO
-o No. of Pages:___
[
i, p 3
,r 333 d.
, m._
ii LC"-