ML19206A533
| ML19206A533 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 12/19/1977 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| Shared Package | |
| ML19206A530 | List: |
| References | |
| IEB-77-07, IEB-77-7, NUDOCS 7904200109 | |
| Download: ML19206A533 (3) | |
Text
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IE Bulletin No. 77-07 Cate: Decemcer 19, ig77 page 2 of 3 reduced the insulation resistance between adjacent conductors.
To prevent further degradation frca moisture buildup within the per.etration assemblies, the licensee re-established a dry nitrogen pressure of 24 PSIG in the penetrations.
Subsequently the licensee recceted that a second event of a similar nature cccurred on October la, 1977.
In this instance tha saacle isc-lation valve for the pressurizer surge line failed to close on command.
Investigation into this event indicated that electrical shcrts between conductors due to a moisture accumulation arcblem were the probable cause for valve miscceration. 7he shorted wires were disconnected and the valve was de-energi:ed in the closed position.
In discussions en the issue with the licensee and tne electrical pene-tration vendce, General Electric Company, NRC staff determined that maintenance of nitrogen pressure is essential to the integrity of both high ar.d low voltage penetration assemblies. The General Electric Company specifies in its penetration assembly maintenance and cceration manual that a 15 pSIG dry nitrogen pressure should be maintained en icw voltage units while 30 PSIG snculd be maintained on high voltage units.
.ution To Be Taken 3y Applicants Of all Pcwer Reactor Facilities With a Construction Permit:
Containment Electrical penetrations - For safety related systems 1.0 Co ycu have containment electrical ;enetrations that are of the G.
E. Series 1CO, er are otherwise similar in that they decend upcn an epoxy sealant and a dry nitrogen cressure envircement to ensure that the electrical and pressure characteristics are maintained se as to ensure the functional capability as recuired by the plant's safety analytis report; namely, (1) to ensure adequate functioning of electrical safety-related ecuipment and (2) to ensure contain-ment leak tightness? if ycu do use ;enetrations of this ty;e at your facility describe the manufacturer and model number of these units.
l.1 If you do not have penetration assemblies of the type (s) referenced in Item 1.0 above, describe the type (s) of penetrations e.g.,
manufacturer and mcdel number new in use er planned for use in safety systems at your facility.
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~J 7904200/07
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IE Sulletin Mc. 77-07 Cate: December 19, 1977 Page 3 of 3 1.2 Oc the transition connector pins imbedded in the epoxy as discussed in Item 1.0 above, have an insulation jacket?
2.0 For those penetrations referenced in Item 1 abcve, has the manu-facturer's prescribed nitrogen pressure been maintained at all times during shipping, storage, and installation?
3.0 Is there a need, as determined by either the vendce or ycurself, to maintain penetrations :ressuri:ed during normal operation, to assure functionability during a LOCA.
3.1 What measures have ycu taken to ensure that penetrations of this type will perform their design function under LOCA conditions?
(design reviews, analyses, ce tests)?
3.2 Are the measures that provide this assurance adequate to satisfy the Ccemission's regulations (GCC 4, Appendix A to Part 50; CA Criteria, Appendix 3 :: Part 50)?
4.0 Previde your response to Items 1.0 thecugh 3.2 above in writing within 30 days. Responses shculd be submitted to the Director of the acpropriate NRC Regional Office. A copy of your response shculd be forwarded to the, U. S. Nuclear Regulatory Ccemission, Office of Ins:ection and Enforcement, Divisien of Reacter Ccnstruction Inspection, Washington, D. C.
20555.
Approved by GAO, 313C225 (RC072); clearance exoires 7-31-80.
Acproval was given under a blanket clearance specifically fer identified generic problems.
L3 e' *
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IE Sulletin No. 77-07 December 19, 1977 LIST!?tG OF IE SULLETINS ISSUED IN 1977 Sulletin Subject n te Issued Issued To a
No.
77-06 Potential Problems with 11/22/77 All Power Peactor Containment Electrical Facilities with an Penetration Assemblies Operating License (OL)77-05A Supplement 77-05A to 11/15/77 All Pcwer Reactor IE Sulletin No. 77 Facilities with an Electrical Ccnnecter Operating License (CL}
Assemolies or Construction Permit (CP) 77-05 Electrical Connector 11/2/77 All Power Reacter Assemblies Facilities with an Operating License (CL) or Construction Pernit (CP) 77-04 Calcuirtional Error 11/4/77 All PWR Pcwer Affecting the Design Reacter Facilities Performance of a System with an Operating for Controlling PH cf Ljcense (OL) er Centainment Sumo Water Construction Permit Following a LOCA (CP) 77-02 On-Line Testing of 9/12/77 All W Pcwer Reacter the 1 Solid State FaciTities with an Protection System Operating License (OL) er Construction Permit (CP) 77-02 Pctantial Failure 9/12/77 All Holders of Mechanism in Certain Oceratina Licenses 1 AR Relays with La ch (OL) er Construction Attachments Permits (CP) 77-01 Pneumatic Time 4/29/77 All Heiders of Delay Relay Set Operating Licenses Point Orift (OL) er Ccnstruction Permits (CP) r* - 4 G7 gj e'
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