ML19351G187
| ML19351G187 | |
| Person / Time | |
|---|---|
| Site: | Shoreham File:Long Island Lighting Company icon.png |
| Issue date: | 01/14/1981 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Pollock M LONG ISLAND LIGHTING CO. |
| Shared Package | |
| ML19351G181 | List: |
| References | |
| NUDOCS 8102230241 | |
| Download: ML19351G187 (1) | |
Text
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%.....,&,4 KING OF PRUSSIA, PENNSYLVANtA 19406 Docket No. 50-322 January 14, 1981 Long Island Lighting Company ATTN:
Mr. M. S. Pollock Vice President - Nuclear 175 East.0ld Country Road Hicksville, New York 11801 Gentlemen:
The enclosed IE Bulletin No. 80-25 " Operating Problems with Target Rock Safety-Relief Valves at BWRs," is forwarded to you for action.
A written response is required.
In order to assist the NRC in evaluating the value/ impact of each Bulletin en licensees, it would be helpful if you would provide an estimate of the manpcwer expended in conduct of the review and preparation of the report (s) required by the Bulletin.
Please estimate separately the manpower associated with corrective actions following identification of problems through the Bulletin.
If you desire additional information regarding this matter, please contact this office.
Sincerely, Bo[yceH.Grier 2
//
Director
Enclosures:
1.
List of Recently Issued IE Bulletins CONTACT:
D. L. Caphton (215-337-5266) cc w/encis:
J. P. Novarro, Prcject Manager Edward M. Barrett, Esquire Edward J. Walsh, Esquire T. F. Gerecke, Manager, Engineering QA Department 9
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SSIN,5 No.: 6820 ccession 8012170482 IEB'80-25 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 December 19, 1980 IE Bulletin No. 80-25: OPERATING PROBLEMS WITH TARGET ROCK SAFETY-RELIEF W'.VES AT BWRs Description of Circumstances:
Five events.have occurred over a three-month period involving two types of malfunctions of the Target Rock (TR) safety-relief (S/R) valves at Boston Edison Company's Pilgrim Nuclear Power Station Unit 1.
On two occasions (July 25 and August 1, 1980), the "D" S/R valve failed to open in response to manual demand.
This same "D" valve failed to reclose in response to manual control actions on October 1, 1980.
On October 7 =ad 31, 1980, the "A" S/R valve opened spuriously while the reactor was operating at power and did not reclose in response to repeated attempts until the reactor was shut down and the reactor coolant system depressurized.
The first three events represented failures of the S/R valve, whereas the last two events resulted from failures of the nitrogen supply system pressure regulation.
The S/R valves at Pilgrim are two-staae, pilot-operated, dual purpose valves designed by Target Rock Corporation ir accordance with GE criteria for service applicatica in the GE BWR main steam system.
The two-stage S/R valve has been designed to replace the TR three-stage S/R valve that had a tendency to leak at the pilot valve and thereby keep the main disk from reseating.
The replacement of the three-stage valves at Pilgrim was accomplished during the refueling outage that was completed in May 1980.
The Pilgrim reactor has four of the two-stage S/R valves installed plus two spring-loaded safety valves.
When the "0" S/R valve failed to open on July 25, 1980, this event was determined to be caused by a failure of its solenoid actuator to function.
During
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fabrication, the excessive use of Loc-tite (i.e., a trademark adhesive for nuts and bolts) caused the solenoid plunger to adhere to the bonnet, thus preventing pneumatic pressure from entering the pneumatic operator.
When the second failure of the "D" valve to open on August 1, 1980 was investigated, no discrete cause was found.
The investigation involved the removal, disassembly, inspection and testing of only the top-works of the valve.
It did not in:.iude, however, a corresponding inspection and testing of the main-stage internals including the piston and guide.
The October 1, 1980 failure of the "D" valve to reclose was concluded to be caused by foreign material being lodged between piston and guide of the main stage of the valve. This conclusion was reached when scoring marks on the surfaces of the piston and guide were found, although no foreign material was recovered.
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6 IEB 80-25 December 19, 1980 Page 2 of 3 i
l The two remaining events of October 7 and 31, 1980 involved the "A" S/R valve i
that spuriously opened and depressurized the reactor coolant system.
These events represented failures of the pneumatic system when excessive pressure in the nitrogen supply system caused the "A" valve to open and then to stay i
open.
The events were addressed in IE Information Notice No. 80-40, " Excessive Nitrogen Supply Pressure Actuates Safety-Relief Valve Operation to Cause i
Reactor Depressurization," that was issued on November 7, 1980.
General Electric recently provided recommendations with regard to these two events caused by high pneumatic supply pressure.
Ac. tion to be Taken by Utilities with BWR Plants with Operating Licenses or Near-Term Operating Licenses:
1.
If your facility has not yet installed or changed or is presently in the i
process of changing to the two-stage S/R valves, initiate appropriate
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quality control procedures to assure inspection of the solenoid actuators for excess Loc-tite prior to operation.
If the solenoid actuator manu-i factured by Target Rock Corporation is already installed in your facility, confirm its operability either by its operational performance (i.e., it has functioned as designed following an aging period of about 3 months in the higher temperature environment of power operating conditions) or by functional testing at full pressure during the next refueling shutdown of the facility.
Include in your report the results of all i
attempts to operate the two-stage S/R valve (s).
2.
In the event that a S/R valve, regardless of make or model (e.g., both two or three stage), fails to function as designed, excepting for pressure setpoint requirements, and the cause of the malfunction is not clearly i
i determined, understood, and therefore corrected, standard operating procedures shall require that the entire valve be removed from service, disassembled, inspected, adjusted, and pressure setpoint tested with l
steam for proper operation prior to returning the valve to service.
These overhaul requirements shall be at least equivalent to those applicable to periodic surveillance rehabilitation requirements.
Appropriate revisions to your operating procedures shall be made to include these requirements.
3.
A review of your S/R valve pneumatic supply systems shall be performed to determine the potential for and magnitude of an overpressure condition.
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The determined overpressure potential of the pneumatic supply shall be compared with the maximum operating pressure capabilities of the solenoid actuator valves serving the S/R valves, so as to determine whether supply pressure could result in valve malfunction.
Protective devices (such as relief valves) shall be installed in the proximity of the S/R valves and set to protect against supply pressure in excess of the operating pressure capabilities of the solenoid actuator device.
In addition, consideration should be given to modification or replacement to reduce the sensitivity of the solenoid actuator to pneumatic supply overpressure.
Further, the failure, either high or low, of the pneumatic supply system shall be annunciated to the control room operator.
The annunciated supply pressure should be measured at a location as close as practical to the S/R 4
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IEB 80-25 December 19, 1980 Page 3 of 3 valves and downstream of any check valve connecting two or more pneumatic sources. Appropriate operating procedures shall be provided to guide operator response to such an occurrence of high or low supply pressure.
4.
The results of your review in response to each of the three items above shall be provided within 90 days of the date of this bulletin.
The system upgrading identified in Item 3 shall be completed within 6 months of the time that you conclude a replacement or modification would be made and the necessary parts are available; this upgrading shall be reported when completed.
Provide written reports as required above, signed under oath or affirmation, under the provisions of Section 182a of the Atomic Energy Act of 1954.
Reports shall be submitted to the Director of the appropriate Regional Office and a copy forwarded to the Director, Office of I.ispection and Enforcement, NRC, Washington, D.C. 20555.
This request for information was approved by GA0 under a blanket clearance number R0072 which expires November 30, 1983.
Comments on burden and duplication should be directed to U. S. General Accounting Office, Regulatory Reports Review, Room 5106, 441 Eighth Street, N. W., Washington, D. C. 20548 l
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IE 8ulletin No. 80-25 December 19, 1980 RECENTLY ISSUED IE BULLETINS Bulletin Subject Date Issued Issued To No.
Supplement 4 Failure of Control Rods 12/18/80 All holders of a to 80-17 to Insert During a BWR power reactor Scram at a BWR OL or CP 80-24 Prevention of Damage Due 11/21/80 All holders of a to Water Leakage Inside power reactor OL Containment (October 17, or CP 1980 Indian Point 2 Event) 80-23 Failures of Solenoid 11/14/80 All holders of a Valves Manufactured by power reactor OL Valcor Engineering or CP Corporation 80-22 Automation Industries, 9/12/80 All holders of a Model 200-520-008 Sealed-radiography license Source Connectors 80-21 Valve Yokes Supplied by 11/6/80 All holders of a Malcolm Foundry Company, Inc.
power reactor OL or CP Revision 1 Boron Loss from 8/29/80 All holders to 79-26 BWR Control Blades of a BWR power reactor OL Revision 1 Failures of Mercury-8/15/80 All holders of a to 80-19 Wetted Matrix Relays in power reactor Reactor Protective OL or CP Systems of Operating Nuclear Power Plants Designed by Combustion Engineering 80-20 Failures of Westinghouse 7/31/80 All holders of a Type W-2 Spring Return to power reactor OL Neutral Control Switches or CP 80-19 Failures of Mercury-7/31/80 All holders of a Wetted Matrix Relays in power reactor OL Reactor Protective Systems or CP of Operating Nuclear Power Plants Designed by Combustion Engineering 9
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