Information Notice 1992-69, Water Leakage from Yard Area Through Conduits into Buildings

Water Leakage from Yard Area Through Conduits into Buildings

ML031200336
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, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	09/22/1992
Revision:	0
From:	Rossi C E Office of Nuclear Reactor Regulation
To:
References
IN-92-069, NUDOCS 9209160134
Download: ML031200336 (7)

UNITED STATES= NUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR REACTOR REGULATIONWASHINGTON, D.C. 20555September 22, 1992NRC INFORMATION NOTICE 92-69: WATER LEAKAGE FROM YARD AREA THROUGHCONDUITS INTO BUILDINGS

Addressees

All holders of operating licenses or construction permits for nuclear powerreactors.

Purpose

The U.S. Nuclear Regulatory Commission is issuing this information notice toalert addressees to problems resulting from large amounts of water leakinginto the reactor building through electrical conduits. It is expected thatrecipients will review the information for applicability to their facilitiesand consider actions, as appropriate, to avoid similar problems. However,suggestions contained in this information notice are not NRC requirements;therefore, no specific action or written response is required.

Description of Circumstances

On November 19, 1991, following a thunderstorm, the licensee for the GrandGulf Nuclear Station observed a significant amount of rain water entering theauxiliary building through electrical conduits. Most of the leakage was fromaround one condulet cover plate; a number of other condulet cover plates weredripping water. The conduits originated in a large manhole located in theadjacent yard area through which the licensee had routed many electric cablesby way of an underground conduit. The licensee found that the sump pump inthis manhole was not operating, probably because of heavy rainfall on thecircuit box, which tripped the circuit breaker for the pump. Water thencollected in the manhole and flowed through the conduits which Were routedinto the auxiliary building. These conduits were to have internal seals nearthe wall of the auxiliary building and upstream of the leaking condulet coverplates. The licensee found that some seals were below or downstream of thecondulet cover plates. Water that leaked from the conduits collected on thefloor, ran through a doorway into the division I switchgear room, and passedthrough floor drains to the radwaste collection tank. About 30,000 gallons ofwater collected in these tanks. Water marks indicated the maximum water levelon the floor was about 1 inch. No safety systems were affected.On December 22, 1991, a 36-inch fiberglass auxiliary circulating water linefailed at the Perry Nuclear Power Plant. The failure was in a non-isolablesection located in a yard area above grade just before the line enters theheater bay building. An estimated 2.9 million gallons of water was pumped outof the break. A small percentage of this amount entered the auxiliary9209160134 A IN 92-69September 22, 1992 building, the heater bay, the service water pump house, and the emergencyservice water (ESW) pump house. Two electrical manholes had previously leakedduring rains and were not designed to be leak tight against standing water.Conduits in these manholes formed a direct path into the buildings where thecables enter. In particular, water entered the ESW pump house through aseries of conduits and ran down a cable into a compartment of a motor controlcenter (MCC), causing a short circuit in a space heater transformer. This MCCalso contained safety-related equipment, which was not damaged.DiscussionIn both instances, large quantities of water entered buildings and areaswithin the buildings that contain safety-related equipment. The leak paththrough yard manholes and connecting electrical conduits was not explicitlyconsidered in the safety analysis. At Grand Gulf, although seals installed inmanholes and conduits were not required to be leak tight against water intru-sion, the licensee found them to be deficient with respect to a designdrawing. These conduits were sealed. The licensee for Perry also sealed theconduits. The licensees did not inspect seals or perform tests that woulddetect the absence or deterioration of installed seals.This information notice requires no specific action or written response. Ifyoui-ave any questions about the in'formation in this n-oti'-e,-pleasecontact ~-the technical contact listed below or the appropriate Office of NuclearReactor Regulation (NRR) project manager.Charles E. Rossi, Director ; rDivision of Operational Events AssessmentOffice of Nuclear Reactor RegulationTechnical contact: J. Carter, NRR(301) 504-1153

Attachment:

List of Recently Issued NRC Information Notices K-IAttachmentIN 92-69September 22, 1992Page 1 of ILIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to91-29,Supp. 192-6892-67Deficiencies IdentifiedDuring Electrical Dis-tribution System Func-tional InspectionsPotentially SubstandardSlip-On, Welding Neck,and Blind FlangesDeficiency in DesignModifications to Ad-dress Failures ofHiller Actuators UponA Gradual Loss ofAir Pressure09/14/9209/10/9209/10/92All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.92-66--Access-Denied to NRCInspectors at Five StarProducts, Inc. andConstruction ProductsResearch, Fairfield,Connecticut09/01/92All holders-of-OLs or CPsfor nuclear power reactorsand all recipients ofNUREG-0040, "Licensee, Con-tractor and Vendor Inspec-tion Status Report" (WhiteBook).92-6592-6492-63Safety System ProblemsCaused by ModificationsThat Were Not AdequatelyReviewed and TestedNozzle Ring Settingson Low Pressure Water-Relief ValvesCracked Insulators inASL Dry Type TransformersManufactured by Westing-,house Electric CorporationEmergency ResponseInformation Require-ments for RadioactiveMaterial Shipments09/03/9208/28/9208/26/9208/24/92All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.All U.S. Nuclear RegulatoryCommission licensees.92-62OL = Operating LicenseCP = Construction Permit IN 92-69September 22, 1992 building, the heater bay, the service water pump house, and the emergencyservice water (ESW) pump house. Two electrical manholes had previously leakedduring rains and were not designed to be leak tight against standing water.Conduits in these manholes formed a direct path into the buildings where thecables enter. In particular, water entered the ESW pump house through aseries of conduits and ran down a cable into a compartment of a motor controlcenter (MCC), causing a short circuit in a space heater transformer. This MCCalso contained safety-related equipment, which was not damaged.DiscussionIn both instances, large quantities of water entered buildings and areaswithin the buildings that contain safety-related equipment. The leak paththrough yard manholes and connecting electrical conduits was not explicitlyconsidered in the safety analysis. At Grand Gulf, although seals installed inmanholes and conduits were not required to be leak tight against water intru-sion, the licensee found them to be deficient with respect to a designdrawing. These conduits were sealed. The licensee for Perry also sealed theconduits. The licensees did not inspect seals or perform tests that woulddetect the absence or deterioration of installed seals.This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactthe technical contact listed below or the appropriate Office of NuclearReactor Regulation (NRR) project manager.Orig /s] 'd by CItirmesChar es .Ro si, irectorDivision of Operational Events AssessmentOffice of Nuclear Reactor RegulationTechnical contact: J. Carter, NRR(301) 504-1153

Attachment:

List of Recently Issued NRC Information Notices*SEE PREVIOUS CONCURRENCESOFC OEAB:DOEA ADM:RPB SC/OEAB:DOEA PD3-3:ADR3NAME JCarter* JMain* RDennig* JHall*DATE 07/01/92 07/06/92 07/13/92 07/09/92OFC PD4-1:ADR4-5 C/OEAB:DOEA C/OGCB:DOEA D/DOEA ANAME PO'Connor* AChaffee* GHMarcus* CRossiDATE 07/09/92 07/13/92 09/15/92 09/ 3/92OFFICIAL RECORD COPYDOCUMENT NAME: 92-69.IN 111IN 92-XXSeptember xx, 1992 Conduits in these manholes formed a direct path into the buildings where thecables enter. In particular, water entered the ESW pump house through aseries of conduits and ran down a cable into a compartment of a motor controlcenter (MCC), causing a short circuit in a space heater transformer. This MCCalso contained safety-related equipment, which was not damaged. Correctiveactions included sealing conduits to preclude future leakage.DiscussionIn both instances, large quantities of water entered buildings and areaswithin the buildings that contain safety-related equipment. The leak paththrough yard manholes and connecting electrical conduits was not explicitlyconsidered in the safety analysis. At Grand Gulf, although seals installed inmanholes and conduits were not required to be leak tight against water intru-sion, the licensee found them to be deficient with respect to a designdrawing. These conduits were sealed. The licensee for Perry also sealed theconduits. The licensees did not inspect seals or perform tests that woulddetect the absence or deterioration of installed seals.This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactthe technical contacts listed below or the appropriate Office of NuclearReactor Regulation (NRR) project manager.Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor RegulationTechnical contact: J. Carter, NRR(301) 504-1153

Attachment:

List of Recently Issued NRC Information Notices*SEE PREVIOUS CONCURRENCESOFC JOEAB:DOEA ADM:RPB SC/OEAB:DOEA PD3-3:ADR3NAME lJCarter* JMain* RDennig* JHall*07/01/92 07/06/92 07/13/92 07/09/92OFC PD4-1:ADR4-5 C/OEAB:DOEA C/OGCB:DOEA D/DOEANAME PO'Connor* AChaffee* u CI CRossillDATE 07/09/92 07/13/92 1 //5/92 / /92OFFICIAL RECORD COPYDOCUMENT NAME: C:\WTRLEAK.R1 (ATB)

IN 92-XXJuly xx, 1992 Conduits in these manholes formed a direct path into the buildings where thecables enter. In particular, water entered the ESW pump house through aseries of conduits and ran down a cable into a compartment of a motor controlcenter (MCC), causing a short circuit in a space heater transformer. This MCCalso contained safety-related equipment, which was not damaged. Correctiveactions included sealing conduits to preclude future leakage.DiscussionIn both instances, large quantities of water entered buildings and areaswithin the buildings that contain safety-related equipment. The leak paththrough yard manholes and connecting electrical conduits was not explicitlyconsidered in the safety analysis. The licensees apparently did not inspectall seals installed during construction. Any seals installed in manholes andconduits were not required to be leak tight against water intrusion. Thelicensees do not routinely inspect seals and do not perform any tests thatwould detect the absence or deterioration of installed seals.This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactthe technical contacts listed below or the appropriate Office of NuclearReactor Regulation (NRR) project manager.Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor RegulationTechnical contact:J. Carter, NRR(301) 504-1153

Attachment:

List of Recently Issued NRC Information Notices*SEE PREVIOUS CONCURRENCESOFC OEAB:DOEA ADM:RPB SC/OEAL DOEA PD3-3:ADR3NAME JCarter* JMain* JHall*[DATE I 07/01/92 07/06/92 1 I/1 92 07/09/92OFC PD4-1:ADR4-5 .ifC/OGCB:DOEA ifD/DOEANAME PO'Connor* af V 6e4 CBerlinger l CRossiD 07/09/92 1 / I92 / /92 [ / /92OFIIA ECR OP OCMN NM: :WRLA (TBOFFICIAL RECORD COPYDOCUMENT NAME: C:\WTRLEAK(ATB)

IN 92-XXJune xx, 1992 entered the (ESW) pump house through a series of conduits and ran down a cableinto a compartment of a motor control center (MCC), causing a space heatertransformer to short. This MCC also contained safety related equipment which,however, was not damaged. Corrective actions included sealing conduits topreclude future leakage.DiscussionIn both instances large quantities of water entered buildings and areas withinthe buildings that contain safety related equipment. The leak path, ie., viayard manholes and connecting electrical conduits, was not explicitly consid-ered in the safety analysis. Inspection of seals installed during construc-tion does not appear to have been comprehensive. Any seals installed inmanholes and conduits were not required to be leak tight against water intru-sion. The seals are not routinely inspected nor is any testing done thatwould detect the absence or deterioration of installed seals.This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactthe technical contacts listed below or the appropriate Office of NuclearReactor Regulation (NRR) project manager.Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor RegulationTechnical contact:J. Carter, NRR(301) 504-1153

Attachment:

List of Recently Issued NRC Information NoticesOFC jf _EA ADM:RPB SC/OEAB:DOEA PD3-3:ADR3NAME art JMain 9T RDennig JHallDATE /1/92 7/G /92 / /92 7/7/92OFC PD4-1:ADR4-5 C/OEAB:DOEA C/OGCB:DOEA D/DOEANAME PO'Connor ¶ AChaffee CBerlinger CRossiDATE 2 /c9/92 / /92 I/ /92 / /92OFFICIAL RECORD COPYDOCUMENT NAME: C:\WTRLEAK(ATB)