ML19305D596
| ML19305D596 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 03/31/1980 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Finfrock I JERSEY CENTRAL POWER & LIGHT CO. |
| References | |
| NUDOCS 8004150269 | |
| Download: ML19305D596 (1) | |
Text
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UNITED STATES a
8 NUCLEAR REGULATORY COMMISSION o
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REGION 1 0,%
g 631 PARK AVENUE KING OF PRUSSIA, PENNSYLVANIA 19406
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March 31, 1980 Docket No. 50-219 Jersey Central Power and Light Company ATTN:
Mr. Ivan R. Finfrock, Jr.
Vice President Madison Avenue at Punch Bowl Road Morristown, New Jersey 07960 Gentlemen:
The enclosed IE Information Notice No. 80-12, " Instrument Failure Causes Opening of PORV and Block Valve," is forwarded to you for information.
No written response is required.
If you desire additional information regarding l
this matter, please contact this office.
Sincerely, M
w f h VKW
/
Boyce H. Grier i
" Director
Enclosures:
1.
IE Information No. 80-12 2.
List of Recently Issued IE Information Notices CONTACT:
W. H. Baunack (215-337-5253) t cc w/encls:
J. T. Carroll, Station Superintendent t
1 80041502[pf
ENCLOSURE 1 SSINS No.:
6870 Accession No.:
UNITED STATES 8002280654 NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Information Notice No.: 80-12 Date:
March 31, 1980 Page 1 of 1 INSTRUMENT FAILURE CAUSES OPENING OF PORV AND BLOCK VALVE Description of Circumstances:
On August 13, 1979, during full, steady-state power operation at the Connecticut Yankee Haddam Neck Plant, the pressurizer power operated relief valve (PORV) and its isolation (block) valve opened as a result of failure of a light source in the sigma bistable of the pressurizer pressure controller.
The failure of the light source was equivalent in control system response to an overpressure condition in the pressurizer.
By system design both PORV and block valves are closed during normal operation and therefore both valves are required to open in response to an overpressure condition.
The opening of the PORV and block valve allowed the pressurizer pressure to drop from its normal value of 2000 psig to 1950 psig before the PORV and block valves could be closed.
The operator immediately overrode the open signal to the valves and closed the valves to stop depressurization.
The pressurizer pressure then immediately returned to normal.
The light source was subsequently replaced in the bistable and the pressure control system was returned to normal.
The licensee reported that failures of light sources in the bistable of this pressure controller and in other similar plant bistables had been experienced previously.
Also, subsequently on February 4, 1980, a spurious signal from the pressure controller caused both PORV and block valve to open.
In both events, the operator responded immediately and effectively to limit the conse-quences of the event to a relatively mild pressure transient on the reactor coolant system.
The licensee also indicated that it had changed out the type of bistable with a solid state design which does not depend on a light source and which is expected to be more reliable.
l 1
This infonnation is provided as notification of a possibly significant matter.
I It is expected that receipients will review the information for possible applicability to their facilities.
No specific action or response is requested at this time.
If you have questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
V ENCLOSURE 2 IE Information Notice No. 80-12 Date:
March 31, 1980 Page 1 of 1 RECENTLY ISSUED IE INFORMATION NOTICES Information Subject bate Issued to Notice No.
Issued 79-37 Cracking in Low Presssure 12/31/79 All Power Reactor Faci-Turbine Discs lities with an Operating License (OL) or Construc-tion Permit (CP) 80-01 Fuel Handling Events 1/4/80 All Power Reactor Faci-lities with an OL or CP 80-02 8X8R Water Rod Lower 1/25/80 All BWR Facilities with End Plug Wear an OL or CP 80-03 Main Turbine Electro-1/31/80 All Power Reactor Faci-hydraulic Control System lities with an OL or CP 80-04 BWR Fuel Exposure in Excess 2/4/80 All BWR Facilities with of Limits an OL or CP 80-05 Chloride Contamination of 2/8/80 All Power Reactor Faci-Safety Related Piping and lities with an OL or CP Components and applicants for a CP 80-06 Notification of Signif-2/27/80 All Power Reactor Faci-icant Events lities with an OL and applicant for OL 80-07 Pump Fatigue Cracking 2/29/80 All Power Reactor Faci-lities with an OL or CP 80-08 The States Company Sliding 3/7/80 All Power Reactor Faci-Link Electrical Terminal lities with an OL or CP Block 80-09 Possible Occupational Health 3/7/80 All Power Reactor Faci-t Hazard Associated with Closed lities with an OL or CP Cooling Systems for Operating Power Plants 80-10 Partial Loss of Non-Nuclear 3/7/80 All Power Reactor Faci-Instrument System Power Sup-lities with an OL or CP ply During Operation 80-11 Generic Problems With ASCO 3/14/80 All Power Reactor Facil-Valves in Nuclear Applica-ities with an OL or CP, tions including Fire Pro-Fuel Fabrication and tection Systems Processing Facilities l