Information Notice 1990-19, Potential Loss of Effective Volume for Containment Recirculation Spray at PWR Facilities

Potential Loss of Effective Volume for Containment Recirculation Spray at PWR Facilities

ML031130259
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, 03000306, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	03/14/1990
From:	Rossi C E Office of Nuclear Reactor Regulation
To:
References
IN-90-019, NUDOCS 9003080213
Download: ML031130259 (8)

IUNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR REACTOR REGULATIONWASHINGTON, D.C. 20555March 14, 1990NRC INFORMATION NOTICE NO. 90-19: POTENTIAL LOSS OF EFFECTIVE VOLUME FORCONTAINMENT RECIRCULATION SPRAY ATPWR FACILITIES

Addressees

All holders of operating licenses or construction permits for pressurized water1 reactors (PWRs).

Purpose

This information notice is intended to alert addressees to the possible loss ofeffective volume for containment recirculation spray caused by the entrapmentof water in the refueling canal of PWRs. It is expected that recipients willreview the information for applicability to their facilities and consideractions, as appropriate, to avoid similar problems. However, suggestionscontained in this information notice do not constitute NRC requirements;therefore, no specific action or written response is required. This infor-mation notice resolves and completes action on Generic Safety Issue 95,*Loss of Effective Volume for Containment Recirculation Spray."

Description of Circumstances

In 1983, the NRC staff resident inspector at H. B. Robinson Unit 2 questionedthe licensee's practice of leaving the refueling canal drain valve in theclosed position during plant operation. The specific concern was that ifthe refueling canal drain valve tina PWR dry containment Is closed duringplant operation and the plant experiences a loss-of-coolant accident (LOCA),that fraction of the containment spray which falls into the refueling canalwould be prevented from returning to the containment emergency sump. Eventu-ally the entire volume of the refueling canal could be filled with water,preventing that amount of water from being available for the post-LOCA re-circulation mode for containment and reactor cooling.A subsequent investigation by the H. B. Robinson licensee revealed thatWestinghouse had intended the refueling canal drain valve to be open duringoperation. However, operation with the valve closed was found to havenegligible safety significance because the maximum volume of water thatcould be entrapped in the refueling canal was small relative to the largevolume of water available from the refueling water storage tank. Never-theless, the licensee decided to operate the plant with the valve openand revise plant procedures accordingly.9003080213 b

ICIN 90-19March 14, 1990 The staff reviewed the licensee's response and corrective action (operationwith the drain valve open) and found them acceptable. Further, the staffconsidered the potential generic implications of this issue. Of particularconcern was whether there are large spaces that might entrap the recirculationwater and whether this water can be adequately drained to the containment sump.The staff addresses this concern in the design review under Standard ReviewPlan (SRP) Section 6.2.2, 'Containment Heat Removal System." However, thereare PWR plants that were not reviewed under SRP Section 6.2.2 to determine ifthe entrapment of containment recirculation water could occur. There are 27PWR plants licensed before SRP Section 6.2.2 was issued. Other PWR plants werereviewed under SRP Section 6.2.2, but plant procedures may not have been ex-plicitly evaluated for this safety matter.Safety Significance:The principal concern is the potential for the entrapment of containment spraywater in operating PWRs. The concern arises because if a sufficient volume ofspray water is prevented from returning to the containment emergency sump,adequate flow in the containment spray recirculation and emergency core coolantrecirculation mode may not be provided. Insufficient flow to the sump canresult in inadequate net positive suction head to the containment spray andlow pressure safety injection pumps. Subsequently, proper post-LOCA contain-ment cooling and reactor core cooling can be disabled.In the NRC staff's evaluation of Generic Safety Issue 95, the staff concludedthat the safety significance of this issue depends primarily upon whether en-trapment of an unacceptable volume of containment spray water could occur duringthe recirculation phase. Licensees may wish to review the adequacy of theirprocedures for ensuring proper water drainage to the containment emergency sump.Requiring that the refueling canal drain valves be open while the reactor isoperating or other comparable provisions may be appropriate. In this con-nection, we note that the current plant technical specifications for PWRswith ice-condenser containments include operability and surveillance require-ments for the refueling canal drain valve during power operation.This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contact thetechnical contact listed below or the appropriate NRR project manager.Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor Regulation

Technical Contact:

Chang-Yang Li, NRR(301) 492-0875Attachment: List of Recently Issued NRC Information Notices

.,, I iAttachmentIN 90-19March 14, 1990 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date otNotice No. Subject -Issuance Issued-to90-1890-17Potential Problems withCrosby Safety Relief ValvesUsed on Diesel GeneratorAir Start Receiver TanksWeight and Center ofGravity Discrepanciesfor Copes-Vulcan Valves3/9/903/8/90All holders of OLsor CPs for nuclearpower reactors.All holders of OLsor CPs for nuclearpower reactors.89-59, ..Supp. 2Suppliers of PotentiallyMisrepresented Fasteners3/7/90All holders of OLsor CPs for nuclearpower reactors.90-16 Compliance with NewDecommissioning Rule90-15 Reciprocity: Notificationof Agreement State RadiationControl Directors Be oreBeginning Work in AgreementStates90-14 Accidental Disposal ofRadioactive Materials90-13 Importance of Review andAnalysis of SafeguardsEvent Logs90-12^ Monitoring or Interruptionof Plant Communications90-11 Maintenance DeficiencyAssociated with Solenoid-Operated Valves90-10 Primary Water StressCorrosion Cracking (PWSCC)of Inconel 6003/7/903/7/903/6/903/5/902/28/902/28/902/23/90All materials licensees.All holders of NRCmaterials licenses _._which authorize useof radioactivematerial at temporary,Job sites.All U.S. NRC byproductmaterial licensees.All holders of OLsor CPs for nuclearpower reactors.All holders of OLsor CPs for nuclearpower reactors.All holders of OLsor CPs for nuclearpower reactors.All holders of OLsor CPs for PWRs.OL = Operating LicenseCP = Construction Permit

~ IN 90-19March 14, 1990 The staff reviewed the licensee's response and corrective action (operationwith the drain valve open) and found them acceptable. Further, the staffconsidered the potential generic implications of this issue. Of particularconcern was whether there are large spaces that might entrap the recirculationwater and whether this water can be adequately drained to the containment sump.The staff addresses this concern in the design review under Standard ReviewPlan (SRP) Section 6.2.2, *Containment Heat Removal System." However, thereare PWR plants that were not reviewed under SRP Section 6.2.2 to determine ifthe entrapment of containment recirculation water could occur. There are 27PWR plants licensed before SRP Section 6.2.2 was issued. Other PWR plants werereviewed under SRP Section 6.2.2, but plant procedures may not have been ex-plicitly evaluated for this safety matter.Safety Significance

The principal concern is the potential for the entrapment of containment spraywater in operating PWRs. The concern arises because if a sufficient volume ofspray water is prevented from returning to the containment emergency sump,adequate flow in the containment spray recirculation and emergency core coolantrecirculation mode may not be provided. Insufficient flow to the sump canresult in inadequate net positive suction head to the containment spray andlow pressure safety injection pumps. Subsequently, proper post-LOCA contain-ment cooling and reactor core cooling can be disabled.In the NRC staff's evaluation of Generic Safety Issue 95, the staff concludedthat the safety significance of this issue depends primarily upon whether en-trapment of an unacceptable volume of containment spray water could occur duringthe recirculation phase. Licensees may wish to review the adequacy of theirprocedures for ensuring proper water drainage to the containment emergency sump.Requiring that the refueling canal drain valves be open while the reactor isoperating or other comparable provisions may be appropriate. In this con-nection, we note that the current plant technical specifications for PWRswith ice-condenser containments include operability and surveillance require-ments for the refueling canal drain valve during power operation.This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contact thetechnical contact listed below or the appropriate NRR project manager.Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor Regulation

Technical Contact:

Chang-Yang Li, NRR(301) 492-0875 $ % \Attachment: List of Recently Issued NRC Information NoticesW:2 0-t_ -6Document Name: INFO NOTICE -KADAMBI, LI*SEE PREVIOUS CONCURRENCES h W -*OGCB:DOEA:NRR *SPLB:DST:NRR *RPB:ADM *C/OGCB:DOEA:NRR *D/DET:NRRl NPKadambi CYLi TechEd H ?3CBerlinger AThadani,^02/26/90 03/07/90 03/02/90 03/7/90 03/7/90 03/4 /90IIkv3 (* V

IN 90-XXMarch xx, 1990 The staff reviewed the licensee's response and corrective action (operationwith the drain valve open) and found them acceptable. Further, the staffconsidered the potential generic implications of this issue. Of particularconcern was whether there are large spaces that might entrap the recirculationwater and whether this water can be adequately drained to the containmentsump. The staff addresses this concern in the design review under StandardReview Plan (SRP) Section 6.2.2, Containment Heat Removal System." However,there are PWR plants that were not reviewed under SRP Section 6.2.2 to determineif the entrapment of containment recirculation water could occur. There are 27PWR plants licensed before SRP Section 6.2.2 was Issued. Other PWR plants werereviewed under SRP Section 6.2.2, but plant procedures may not have been ex-plicitly evaluated for this safety matter.Safety Significance:The principal concern is the potential for the entrapment of containment spraywater in operating PWRs. The concern arises because if a sufficient volume ofspray water is prevented from returning to the containment emergency sump,adequate flow in the containment spray recirculation and emergency core coolantrecirculation mode may not be provided. Insufficient flow to the sump canresult in inadequate net positive suction head to the containment spray and lowpressure safety injection pumps. Subsequently, proper post-LOCA containmentcooling and reactor core cooling can be disabled.In the NRC staff's evaluation of Generic Safety Issue 95, the staff concludedthat the safety significance of this issue depends primarily upon whetherentrapment of an unacceptable volume of containment spray water could occurduring the recirculation phase. In order to resolve this potential safetyproblem, licensees may wish to incorporate procedures to ensure proper waterdrainage to the containment emergency sump, such as requiring that the refuel-ing canal drain valves be open while the reactor is operating or consider othercomparable provisions. In this connection, we note that the current planttechnical specifications for PWRs with ice-condenser containments includeoperability and surveillance requirements for the refueling canal drain valveduring power operation.This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contact thetechnical contact listed below or the appropriate NRR project manager.Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor Regulation

Technical Contact:

Chang-Yang Li, NRR(301) 492-0875Attachment: List of Recently Issued NRC Information NoticesDocument Name: INFO NOTICE -KADAMBI, LI Jel\"SEE PREVIOUS CONCURRENCES I*OGCB:DOEA:NRR *SPLB:DST:NRR *RPB:ADM X /OGCB:DOEA:NRR D/D'T:NRR D/DOEA:NRR,gNPKadambi CYLi TechEd CHBerlinger AThadani CERossi02/26/90 03/07/90 03/02/90 03/7/90 0317 /90 03/ /90

IN 90-XXMarch xx, 1990 The staff reviewed the licensee's response and corrective action (operationwith the drain valve open) and found them acceptable. Further, the staffconsidered the potential generic implications of this issue. Of particularconcern was whether there are large spaces that might entrap the recirculationwater and whether these spaces can be adequately drained to the containmentsump. The staff addresses this concern in the design review under StandardReview Plan (SRP) Section 6.2.2, "Containment Heat Removal System." Those PWRplants that were not reviewed under SRP Section 6.2.2 may need to be reviewedcarefully to determine if the entrapment of containment recirculation watercould occur. There are 27 PWR plants licensed before SRP Section 6.2.2 wasissued. Other PWR plants were reviewed under SRP Section 6.2.2, but plantprocedures may not have been explicitly evaluated for this safety matter.Safety Significance:The principal concern is the potential for the entrapment of containment spraywater in operating PWRs. The concern arises because if a sufficient volume ofspray water is prevented from returning to the containment emergency sump,adequate flow in the containment spray recirculation and emergency core coolantrecirculation mode may not be provided. Insufficient flow to the sump canresult in inadequate net positive suction head to the containment spray and lowpressure safety injection pumps. Subsequently proper post-LOCA containmentcooling and reactor core cooling can be disabled.In the NRC staff's evaluation of Generic Safety Issue 95, the staff concludedthat the safety significance of this issue depends primarily upon whetherentrapment of an unacceptable volume of containment spray water could occurduring the recirculation phase. In order to resolve this potential safetyproblem, licensees may wish to incorporate procedures to ensure proper waterdrainage to the containment emergency sump, such as requiring that the refuel-ing canal drain valves be open while the reactor is operating or consider othercomparable provisions. In this connection, we note that the current planttechnical specifications for PWRs with ice-condenser containments includeoperability and surveillance requirements for the refueling canal drain valveduring power operation.This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contact thetechnical contact listed below or the appropriate NRR project manager.Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor Regulation

Technical Contact:

Chang-Yang Li, NRR(301) 492-0875Attachment: List of Recently Issued NRC Information NoticesgfK Document Name: INFO NOTICE -KADAMBI, LI*SEE PREVIOUS CONCURRENCES*OGCB:DOEA:NRR SPLB: 51 NRR *RPB:ADM C/OGCB:DOEA:NRR D/DOEA:NRRNPKadambi CYLi* TechEd CHBerlinger CERossi02/26/90 03/7 /90 03/02/90 03/ /90 03/ /90

-IN 90-XXFebruary xx, 1990 The licensee's response and corrective action (operation with the drain valveopen) were reviewed and found acceptable by the staff. Further, the staffconsidered the potential generic implications of this issue. Of particularconcern was whether there are large volumes that might entrap the recirculationwater and whether these volumes can be adequately drained to the containmentsump. Because of the lack of specific guidance, those PWR plants that were notreviewed under SRP Section 6.2.2L "Containment Heat Removal System," may needto be reviewed carefully to determine if entrapment of containment recircula-tion water could occur. There are 27 PWR plants licensed before SRP Section6.2.2 was issued. Other PWR plants were reviewed under SRP Section 6.2.2 butplant procedures may not have been explicitly evaluated for this safety matter.Safety Significance:The principal concern is the potential for containment spray water entrapmentin operating PWRs. The concern arises because if a sufficient volume of spraywater is prevented from returning to the containment emergency sump, adequateflow in the containment spray recirculation and emergency core coolant recircu-lation mode may not be provided. This can result in inadequate net positivesuction head to the containment spray and low pressure safety injection pumpsand subsequent inability to provide proper post-LOCA containment and reactorcore cooling.In the NRC staff's evaluation of Generic Safety Issue 95 the staff concludedthat the safety significance of this issue depends primarily upon whetherentrapment of an unacceptable volume of containment spray water could occurduring the recirculation phase. In order to ameliorate this potential safetyproblem, licensees may wish to incorporate procedures to ensure proper waterdrainage to the containment emergency sump, such as requiring that the refuel-ing canal drain valve(s) be open while the reactor is operating or considerother comparable provisions. It is noted that the current plant technicalspecifications for PWRs with ice-condenser containments include operability andsurveillance requirements for the refueling canal drain valve during poweroperation.This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contact thetechnical contact listed below or the appropriate NRR project manager.Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor Regulation

Technical Contact:

Chang-Yang Li, NRR(301) 492-0875Attachment: List of Recently Issued NRC Information NoticesDocument Name: INFO NOTICE -KADAMBI, LIOGCB mOEA:NRR SPLB:DST:NRR R d4;6/OGCB:DOEA:NRR D/DOEA:NRRNPKadambi CYLi chEd CHBerlinger CERossi02/1.b/90 02/ /90 f2-/c2 /90 02/ /90 02/ /903