ML20037C726
| ML20037C726 | |
| Person / Time | |
|---|---|
| Site: | Humboldt Bay, Diablo Canyon |
| Issue date: | 01/16/1981 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Crane P PACIFIC GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8102190835 | |
| Download: ML20037C726 (1) | |
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g UNITED STATES 8 %,Q[ *( j NUCLEAR REGULATORY COMMISSION 5 cp *
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SUITE 202. WALNUT CREEK PLAZA
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WALNUT CREE K. CALIFORNtA 94596 January 16, 1981 N
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Docket Nos. 50-133, 50-275, 50-323 E
JAN 2.31981 m {t Pacific Gas and Electric Comoany v.s. m m e u w P. O. Box 7442 p'/
San Francisco, California 94106 Attention:
Mr. Philip A. Crane, Jr.
A Assistant General Counsel Gentlemen:
This Information Notice is provided as an early notification of a possibly significant matter.
It is expected that recipients will review the information for possible applicability to their facilities.
No specific action or response is requested at this time.
If furtner 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 NRC Regional Office.
Sincerely, R
bl -
R. H. Engelken Director
Enclosures:
1.
IE Information Motice 2.
Recently Istued IE Information Motices cc w/ enclosures:
J. D. Shiffer W. Raymond, PG&E R. C. Thornberry, Plant Manager E. Weeks, PG&E, Humboldt Bay E. B. Langley, Jr., PG&E 8102190 755 g
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 INFOR1ATION NOTICE NO. 81-01: POSSIBLE FAILURES OF GENERAL ELECTRIC TYPE HFA RELAYS Puroose:
The intent of this Information Notice is to alert licensees and holders of construction permits of a potentially generic proDiem 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).
Descriotion of Circumstances:
The defective coil spools are fabricated of either black or clear Lexan, a polycarbonate material that is susceptible to surface cracking when exposed to hydrocarbons.
The concern here is that such surface cracks could ultimately deteriorate to such a degree that relay actuation would be blocked by the resultant oebris, thereby innibiting a required safety function.
Indications of the above mencioned cracks were recently detected on the HFA relays used to sequence the emergency ;oads 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 CE type HFA relays highlights two salient points:
(1) HFA relays have had a long history of failures (e.g., GE has issued several Service Infornation 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 Motice No. 80-13 for additional details.)
The above information identifies means whereby the integrity of a major safety-related system can be jeopardized or compromised by the blocking of relay actuation. Accordingly, this Information Motice 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 or required pending the outcome of the NRC staff evaluation.
If you have any cuestion regarding this matter, please contact the director of the appropriate NRC Regional Office.
IU 81-01 January 16, 1981 RECENTLY ISSUED IE INFORMATION NOTICES Information Date of Notice No.
Subj ect Issue Issued to 80-45 Potential Failure of 12/17/80 All PWR facilities SWR Backup Manual Scram with an OL or CP Ccpability 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
'later Level Monitor for facilities with OL the Scram Discharge 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
'!alve in the Decay Heat facilities with an OL 7er. oval System at Davis-cr CP Cesse Unit No.1 80-40 Excessive Nitrogen Supply 11/10/80 All' power reactor Pressure Actuates Safety-facilities with Relief Valve Operation to 0L or CP Cause Peactor Depressur-ization 80-39 Malfunctions of Solenoid 10/31/80 All light water reactor Valves Manufactured By facilities with Valcor Engineering Corporation OLs or cps 80-38 Cracking in Charging Pump 10/30/80 All PWR facilities Casing Cladding with an OL or CP 80-37 Containment Cooler Leaks 10/24/30 All power reactor and Reactor Cavi ty facilities with Flooding at Indian Point OLs or cps Unit 2 OL = Operating Licenses CP = Construction Permits