ML19345C923
| ML19345C923 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 11/10/1980 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| References | |
| NUDOCS 8012080621 | |
| Download: ML19345C923 (1) | |
Text
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k UNITED STATES NUCLEAR REGULATORY COMMISSION
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REGION V o, ',
1990 N. CAUFORNIA BOULEVARD V
SulTE 202, WALNUT CREEK PLAZA WALNUT CREEK, CAUFORNIA 94596 November 10, 1980
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o Docket ilo. 50-312
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P. O. Box 15830 4"
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Attention: Mr. John J. Mattimoe Assistant General Manager Gentlemen:
This Information Notice is provided as an early notification of a possibly significant matter.
It is expected that recipients will re/iew the information for possible applicability to their facilities. I4o specific action or response is requested at this time.
If furtner liRC evaluations so indicate, an IE Circular or Bulletin will be issued to recommend or request specific licensee actions.
If you have questions regarding this aatter, please contact the Director of the appropriate T4RC Regicnal Office.
Sincerely,
. /
(R. H. En/
gelken Director
Enclosures:
1.
IE Information Notice No. 80-41 2.
Recently issued IE Information ilotices cc w/ enclosures:
R. J. Rodriguez, SMUD L. G. Scnwieger, SMUD
'80120R0
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SSINS No.: 6835 Accession No.:
8008220260 UNITED STATES IN 80-41 NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT b
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WASHINGTON, D.C.
20555 V'g o
November 10, 1980 IE Information Notice No. 80-41:
FAILURE OF SWING CHECK VALVE IN THE DECAY HEAT REMOVAL SYSTEM AT DAVIS-BESSE UNIT NO. 1 Descriotion of Circumstances:
On October 9,1980 the resident inscector at the Davis-Besse facility was infomed that the licensee had perforned leak rate tests and identified exces-sive leakage tnrough Decay Heat Removal System check valve CF-30. Valve CF-30 is the' inboard one of two in-series check valves that is used to isolate the reactor coolant system from the low pressure decay heat removal system. On further investigation the licensee found that the valve disc and arm had separated from the valve body and was lodged just under the valve cover plate.
The two 2 5/8 x 5/8 inch bolts and locking mechanism for the bolts that holds the arm to the valve body were missing and have not been located. The CF-30 valve is a 14-inch swing check valve manufactured by Velan Valve Corporation.
The cause of the failure has not been identified.
The test that was in progress when the failure was identified was being con-ducted in response to a letter from Carrell G. Eisenhut, Office of Nuclear Reactor Regulations to all Light Water Reactor Licensees, LWR Primary Coolant System Pressure Isolation Valves, February 23, 1980.
This IE Information Notice is provided as an early notification of a possibly significant matter that is still under review by the NRC staff.
It is expected that recipients will review the information for possible applicability ta their facilities. No specific action or response is requested at this time.
If NRC evaluations so indicate, further licensee actions may be requested or required.
No written response to this IE Infomation Notice is required. If you have any questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
4F IN 80-41 November 10, 1980 RECENTLY ISSUED IE INF0PSATION NOTICES Information Oate of Notice No.
Subject Issue Issued to 80-40 Failure Of Swing Check 11/10/80 All power facilities Valve In The Decay Heat with and OL or CP Removal System At Davis-Besse Unit No.1 80-39 Malfunctions Of Solenoid 10/31/80 All light water reactor
'lalves "anufactured By facilities holding Valcor Engineering Corocration power reactor OLs or cps 80-38' Cracking In Charging Pumo 10/30/80 All PWR facilities Casing Cladding with an OL or CP 80-37 Containment cooler leaks 10/24/80 All nuclear power and reae cr cavity facilities holding flooding at Indian Point power reactor OLs Unit 2 or cps 80-36 Failure of Steam 10/10/80 All nuclear pcwer Generator Supper '. Bolting reactor facilities holding power reactor Ols or cps 80-35 Leaking and dislodged 10/10/80 All categories G and Iodine-124 implant seeds G1 medical licensees 80-34 Boron dilution of reactcr 9/26/80 All pressurized water coolant during steam reactor facilities generator decontamination holding power reactor OLs 80-33 Determination of teletherapy 9/15/80 All teletherapy timer accuracy (G3) licensees 80-32 Clarification of certain 8/12/80 All NRC and agreement requirements for Exclu-state licensees sive-use shipments of radioactive materials 80-31 Maloceration of Gould-8/27/80 All light water reactor Brown Boveri Type 480 facilities holding OLs volt type (-600S and or cps
.<-000 6005 circuit breakers
- Operating Licenses or Construction Permits