Information Notice 1986-50, Inadequate Testing to Detect Failures of Safety-Related Pneumatic Components or Systems

Inadequate Testing to Detect Failures of Safety-Related Pneumatic Components or Systems

ML031220684
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, 05000000, Zimmer, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant, Skagit, Marble Hill
Issue date:	06/18/1986
From:	Jordan E L NRC/IE
To:
References
IN-86-050, NUDOCS 8606160044
Download: ML031220684 (4)

ORIGINAL SSINS No.: 6835IN 86-50UNITED STATES.NUCLEAR REGULATORY COMMISSIONOFFICE OF INSPECTION AND ENFORCEMENTWASHINGTON,,D.C. 20555June 18, 1986IE INFORMATION NOTICE NO. 86-50: INADEQUATE TESTING TO-DETECT FAILURES OFSAFETY-RELATED PNEUMATIC COMPONENTS ORSYSTEMS

Addressees

All nuclear power reactor facilities holding an operating license (OL) or aconstruction permit (CP).

Purpose

This notice is being provided to alert recipients to a potentially significantproblem pertaining to inadequate testing practice relating to air operatedvalves. The NRC expects that recipients will review this notice for applica-bility to their facilities. However, suggestions contained in this notice donot constitute NRC requirements; therefore, no specific action or writtenresponse is required.Past Related Correspondence:IE Information Notice No. 82-25, "Failures of Hiller Actuators UponGradual Loss of Air Pressure," July 20, 1982IE Information Notice No. 85-35,- '.Failure of Air Check Valves to Seat,"April 30, 1985IE Information Notice No. 85-84, "Inadequate Inservice Testing of MainSteam Isolation Valves," October 30, 1985IE Information Notice No. 85-94, 'Potential for Loss of Minimum FlowPaths Leading to ECCS Pump Damage During a LOCA," December 13, 1985

Description of Circumstances

The NRC has reported previously on instances where safety-related equipmentfailed to operate as intended when non-safety-related pneumatic systems wereunavailable (IE INs 82-25 and 85-35). In these situations, main steam isola-tion valves and containment isolation valves failed to operate properly whencontrol air pressure decreased slowly rather than rapidly as would be expectedfor an air line break. In the case of IN 85-35, the fault was exposed by aloss of offsite power test, and in the case of IN 82-25, the fault was exposedby a preoperational test designed .to simulate a slow air leak. In both cases,8606160044 IN 86-50June 18, 1986 the components in question--an accumulator isolation check valve (IN 85-35) andpneumatic selector valves (IN 82-25)--were not tested adequately. Severalrecent events have indicated continuing problems of similar nature. Theseevents are discussed below.On February 13, 1986, the licensee at Turkey Point Unit 3 first reported to thtNRC a concern that the component cooling water (CCW) system might fail to meetits functional requirements for a design-basis accident. One part of theconcern involved the CCW heat exchanger outlet control valve. This valveregulates flow of intake cooling water (ICW) to this heat exchanger. Loss ofcontrol air, coincident with a loss of offsite power, a valid engineeredsafeguards features (ESF) actuation signal, and a loss of an emergency dieselgenerator (EDG) would cause this valve to fail closed. If this happened, theCCW heat exchanger would not receive sufficient flow of ICW. This situationwas discovered during a design review of the ICW system. Earlier disclosuremight have been possible if ICW operation had been considered or tested withnon-safety-related control air secured, coincident with loss of electricalpower.On January 7, 1986, the licensee at Robinson Unit 2 reported a concern with theair-operated valves in the safety injection (SI) pump minimum-flow recircula-tion line from the pump discharge to the refueling water storage tank (RWST).This concern evolved from review of IN 85-94. Two such valves had been insert-ed in series in this line and had been designed to fail closed on loss ofnon-safety-related air or loss of electrical power to the valves. The purposeof the valves is to protect the RWST (outside containment) from highly radioac-tive reactor coolant during the long-term circulation phase of accident recov-ery. In the event of SI initiation under small-break loss-of-coolant-accidentconditions concurrent with closure of either of these valves, the SI pumpswould be operating with no flow until reactor pressure decreased below theirshutoff head. This would damage the SI pumps after only a short time. Thelicensee's remedy was to put mechanical blocks on the air operators so thevalves would fail as-is (open). Again, if SI operation had been considered ortested with non-safety-related control air secured, the fault might have beendisclosed earlier.On December 9, 1985, the licensee at Catawba Unit 2 reported finding that oneof the two valve closure springs was missing on one of the pressurizerpower-operated relief valves (PORVs). Thus, with loss of air the valve wouldnot have closed against system pressure. The other two PORVs had their normalcomplement of springs. The valve with the missing spring had been foundsatisfactory in preoperational tests. During the preoperational loss of airtest, the valve closed because system pressure was not present; during the hotfunctional test, the valve closed because actuator air pressure was present.This is clearly a case in which a fail safe valve was tested without allactuator power secured (IN 85-84).

IN 86-50June 18, 1986 No specific action or written response is required by this information notice.If you have any questions about this matter, please contact the RegionalAdministrator of the appropriate regional office or this office.;d~waA tJordan, DirectorDivisi of Emergency Preparednessand E gineering Response-~ Office of Inspection and Enforcement

Technical Contact:

Vern Hodge, IE(301) 492-7275

Attachment:

List of Recently Issued IE Information Notices Attachment 1IN 86-50June 18, 1986LIST OF RECENTLY ISSUEDIE INFORMATION NOTICESInformation Date ofNotice No. Subject Issue Issued to86-4986-4886-47Age/Environment InducedElectrical Cable FailuesInadequate Testing Of BoronSolution Concentration In TheStandby Liquid Control SystemFeedwater Transient WithPartial Failure Of TheReactor Scram SystemImproper Cleaning And Decon-tamination Of RespiratoryProtection EquipmentPotential Falsification OfTest Reports On FlangesManufactured By Golden GateForge And Flange, Inc.6/16/866/13/866/9/866/12/866/10/8686-4686-4586-44All power reactorfacilities holdingan OL or CPAll BWR facilitiesholding an OL or CPAll BWRs and PWRsfacilities holdingan OL or CPAll power reactorfacilities holdingan OL or CP andfuel fabricationfacilitiesAll power reactorfacilities holdingan OL or CP andresearch and testfacilitiesAll power reactorfacilities holdingan OL or CP andresearch and testreactorsAll power reactorfacilities holdingan OL or CPAll power rectorfacilities holdingan OL or CPAll byproductmaterial licenseesFailure To Follow Procedures 6/10/86When Working In High RadiationAreas86-43Problems With Silver ZeoliteSampling Of Airborne Radio-iodine86-42Improper MaintenanceRadiation MonitoringOfSystems6/10/866/9/866/9/8686-41Evaluation Of QuestionableExposure Readings Of LicenseePersonnel DosimetersOL = Operating LicenseCP = Construction Permit