ML20037C724
| ML20037C724 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 01/16/1981 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| References | |
| NUDOCS 8102190827 | |
| Download: ML20037C724 (1) | |
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION 2
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January 16,1981 ' Ifn. 9,,,@Ro
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Docket No. 50-312 Sacramento Municipal Utility District P. O. Box 15830 Sacramento, California 95813 Attention:
Mr. John J. Mattimce Assistant General Manager Gentlemen:
This Information ilotice is provided as an early notification of a possibly significant matter.
It is expected that recipients will review the information for possible apolicability to their facilities.
No specific action or response is requested at this time.
If further NRC evaluations so indicate, an IE Circular or Bulletin will be issued to recommend or request specific licensee actions.
If you have questions regarding this matter, please contact the Director of the appropriate flRC ?.egional-Of.~ ice.
Sincerely, as yd C.'_
/t. wsh R. H. Engelken Director
Enclosures:
1.
IE Information Notice 2.
Recently Issued IE Information ?!otices cc w/ enclosures.
R. J. Rodriguez, SMLJ
'L. G. Schwieger, SMUD ision1903AT Q
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l SSINS No.: 6835 Accession No.:
8011040254 IN 81-01 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D. C.
20555 January 16, 1981 IE INFORi1ATION f,0TICE NO. 81-01: POSSIBLE FAILURES OF GENERAL ELECTRIC TYPE HFA RELAYS
Purpose:
The intent of this Information Notice is to alert licensees and holders of construction oermits of a potentially generic problem involving defective coil spools used in General Electric (GE) type HFA relays.
Such defective relays were recently found at Turkey Point Unit 4 (Docket No. 50-250).
Description of Circumstances:
The defective coil spools are fabricated of either black or clear Lexan, a polycarbonate materiai that is susceptible to surface cracking when exposed to hydrocarbons. The concern nere is that such surf ace cracks could ultimately deteriorate to sucn a degree that relay actuation would be blocked by the resultant debris, thereoy inhibiting a required safety function.
Indications of the aoove mentioned cracks were recently detected on the HFA relays used to sequence the emergency loads on the diesel generators at Turkey Point Unit 4 upon a loss-of-coolant accident coincident with a loss of offsite power. Af ter detecting the cracks, the spare coils in the storeroom were in-spected and, although these coils are new units, one was found to be cracked.
The possible failures of GE type HFA relays highl bjhts two salient points:
(1) HFA relays have had a long history of failures (e.g., GE has issued several Service Information Letters (SIL) addressing these relays, the oldest one of which dates back to 1973, and it is anticipated that GE will issue a new SIL in the near future addressing this new concern); (2) the cracking phenomena seems to be similar to that experienced on the cam followers used on GE type SBM switches (e.g., these cam followers are fabricated of Lexan, and after their exposure to hydrocarbons during fabrication or during maintenance severe cracking resulted.
See IE Information Notice No. 80-13 for additional details.)
The above information identifies means whereby the integrity of a najor safety-related system can be jeop;rdized or compromised by the blocking of relay actuation.
Accordingly, tht3 Information Notice is provided as an early notification of a possibly significant matter that is still under review by the NRC staff.
Recipients should, therefore, review the information for possible applicability to their facilities.
Although no specific action or response is requested at this time, further licensee actions may be requested cr required pencing the outcome of the NRC staff evaluation.
If you have any question regarding this matter, please contact the director of the appropriate NRC Regional Office.
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Ill 81-01 January 16, 1981 RECENTLY ISSUED IE INFORMATION NOTICES Information Date of flotice flo.
Subject Issue Issued to 80-45 Potential Failure of 12/17/80 All PWR facilities BWP Backup Manual Scram with an OL or CP Capability 80-44 Actuation of ECCS in the 12/16/80 All PWR facilities Recirculation Mode While with an OL or CP in Hot Shutdown 80-43 Failures of the Continuous 12/5/80 All power reactor Water Level Monitor for facilities with OL the Scram Discharoe Volume or CP at Dresden Unit No. 2 80-42 Effect of Radiation on 11/24/80 All power reactor Hydraulic Snubber Fluid facilities with OL or CP 80-41 Failure of Swing Check 11/10/80 All power reactor lalve in the Decay Heat facilities with an OL
'?omoval System at Davis-or CP mese Unit No. 1 80-40
{xcessive Mitrogen Suoply 11/10/80 All power reactor Dressure Actuates Safety-facilities with "elief Valve Operation to OL or CP Cause deactor Depressur-ization 80-39
- alfur:tions of Solenoid 10/31/80 All light water reactor Valves Manufactured By facilities with
'!alcor Engineering Corporatica OLs or cps 80-38 Cracking in Charging Pump 10/30/80 All PWR facilities Casino Cladding with an OL or CP 80-37 Containment Cooler Leaks 10/24/80 All power reactor and Eeactor Cavity facilities with loading at Indian Pcint OLs or cps U n i t