Information Notice 1997-10, Liner Plate Corrosion in Concrete Containments

Liner Plate Corrosion in Concrete Containments

ML031050365
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:	03/13/1997
Revision:	0
From:	Martin T T Office of Nuclear Reactor Regulation
To:
References
IN-97-010, NUDOCS 9703140144
Download: ML031050365 (12)

K> March 13, 1997NRC INFORMATION NOTICE 97-10: LINER PLATE CORROSION IN CONCRETECONTAINMENTS

Addressees

All holders of operating licenses or construction permits for power reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to alertaddressees to occurrences'of corrosion in the liner plates of reinforced and pre-stressedconcrete containmnents, and to detrimental effects such corrosion could have on containmentreliability and availability under design-basis and beyond-design-basis events. It is expectedthat recipients will review this information for applicability to their facilities and consideractions, as appropriate. However, suggestions contained in this information notice are notNRC requirements; therefore, no specific action or written response is required.BackgroundCriterion 16 of the General Design Criteria of 10 CFR Part 50 requires that the reactorcontainment and associated systems shall be provided to establish an essentially leaktightbarrier against the uncontrolled release of radioactivity to the environment. To meet thisleak-tightness requirement, the inside surfaces of concrete containments are lined with thinmetallic plates, generally between 6.2 mm (1/4 in.) and 9.5 mm (3/8 in.) thick. The linerplates are attached to the concrete by means of stud anchors or structural rolled shapes orboth.The design process assumes that the liner plates do not carry loads. However, the normalloads, such as from concrete shrinkage, creep and thermal changes, imposed on theconcrete containment structure are transferred to the liner plates through the anchoragesystem. Internal pressure and temperature loads are directly applied to the liner plate. Thus,under design-basis conditions, the liner plate could experience significant strains.Section III,Division 2 of the American Society of Mechanical Engineers (ASME) Boiler and PressureVessel Code (also called American Concrete Institute Standard 359), "Code for ConcreteReactor Vessels and Containments," allows liner tensile strains up to 0.004 cm/cm (inchfinch)of material for normal operating stresses, and up to 0.01 cm/cm (inch/inch) for stressesresulting from the postulated environmental and accident conditions. American Society forTesting and Materials (ASTM) Standard A516 (or equivalent) steel is typically used in theP6E r4-E 0oTICE97-01/ 970313 Iok 'IFI.IllIEiliIEEP ' ' I C IN 97-10March 13, 1997 construction of containments. The minimum ultimate tensile strain of the liner material is0.2 cm/cm (inch/inch). Thus, there is a minimum safety factor of 20 above the theoreticallycalculated liner strains.Any corrosion (metal thinning) of the liner plate could change the failure threshold of the linerplate under a challenging environmental or accident condition. Thinning changes thegeometry of the liner plate, creating different transitions and strain concentration conditions.This may reduce the design margin of safety against postulated accident and environmentalloads.

Description of Circumstances

Inspections of containment liners have shown various degrees of corrosion.* In January 1993, an NRC inspector pointed out corrosion of the drywell liner at Unit 2of the Brunswick plant. The liner was corroded at various spots at the junction of thebase floor and the liner. A subsequent examination of Unit I showed similarcorrosion.* During the NRC staffs structural assessment review in June 1992, the staff notedpeeled coating and spots of liner corrosion at Trojan (not operating) and at BeaverValley Unit 1.* Before integrated leak rate testing of the containment at Salem Unit 2 in 1993, thelicensee's staff noted minor corrosion of the containment liner.* During the NRC staff's structural assessment review in April 1992, discoloration of thevertical portion of the containment liner was observed at an insulation joint atRobinson Unit 2.DiscussionOf the five occurrences cited above, four (Trojan and Beaver Valley Unit 1, Salem Unit 2, andRobinson Unit 2) were found to be benign from the standpoint of safety. However, thelicensees were sensitized to the conditions for future monitoring and repairs, as appropriate.Corrosion of the liner plate at Brunswick Units 1 and 2 was significant from the standpoint ofsafety. The sealing material along the circumference at the junction of the drywell.wall andthe bottom floor had significantly degraded from the water accumulation at the junction. Theliner plate was found to have pitted significantly (as much as 50 percent of the originalthickness) at various locations along the circumference. Before the restart of the twoBrunswick units, the licensee cleaned the joint areas, repaired the pitted liner plate areas,and resealed the entire gap at the junction with dense silicone elastomer. The repair of thepitted areas consisted of (1) welding the pitted areas, (2) examining the repaired areas inaccordance with the ASME Section III, Division 2, and (3) recoating the repaired area v)IN 97-10March 13, 1997 Corrosion of a liner plate can occur at a number of places where the metal can be exposedto moisture, or where moisture can condense (behind insulation) or accumulate. Potentiallocations for liner plate corrosion are (1) the junction of the containment cylinder andintermediate floors and basemat concrete (PWRs and Mark IlIl BWRs), (2) the junction of thedrywell and the base or intermediate concrete floors (Mark I, Mark II concrete containments),(3) adjacent to crane girder rails and supports attached to the liner plate (concretecontainments), (4) water-soaked areas where carbon steel liner plate is used (Mark II andMark Ill containments), and (5) behind insulation and ice-condenser baskets.An amendment to 10 CFR 50.55a became effective September 9, 1996. This amendment,by endorsing the use of Subsections IWE and IWL of Section Xl of the ASME Boiler andPressure Vessel Code, provides detailed requirements for inservice inspection of containmentstructures. Inspection (which includes examination, evaluation, repair, and replacement) ofconcrete containment liner plate in accordance with the 10 CFR 50.55a requirementsinvolves consideration of the potential corrosion areas.This information notice requires no specific action or written response. If you have anyquestions about information in this notice, please contact one of the technical contacts listedbelow or the appropriate NRR project manager.Thomas T. Martin, DirectoDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical Contacts: Hans Ashar, NRR(301) 415-2851E-mail: hga@nrc~govR. A. Benedict, NRR(301) 415-1157E-mail: rabl@nrc.gov

Attachment:

List of Recently Issued NRC Information NoticesAd 74aI F4 u K2AttachmentIN 97-10March 13, 1997 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to97-09Inadequate Main SteamSafety Valve (MSSV)Setpoints and Perform-ance Issues Associatedwith Long MSSV InletPiping03/12/97All holders of OLsor CPs for nuclearpower reactors97-08Potential Failuresfor General ElectricMagne-Blast CircuitBreaker SubcomponentsProblems IdentifiedDuring Generic Letter89-10 CloseoutInspections03/12/9703/06/97All holders of OLsor CPs for nuclearpower reactorsAll holders of OLsor CPs for nuclearpower reactors97-0797-0691-85,Rev. 197-05Weaknesses in Plant-Specific EmergencyOperating Proceduresfor Refilling theSecondary Side of DryOnce-Through SteamGeneratorsPotential Failures ofThermostatic ControlValves or DieselGenerator JacketCooling WaterOffsite NotificationCapabilities03/04/9702/27/9702/27/97All holders of OLsor CPs for nuclearpower reactors withwith once-throughsteam generatorsAll holders of OLsor CPs for nuclearpower reactorsAll holders of OLsor CPs for nuclearpower reactors andtest and researchreactorsOL = Operating LicenseCP = Construction Permit IN 97-10March 13, 1997 Corrosion of a liner plate can occur at a number of places where the metal can be exposedto moisture, or where moisture can condense (behind insulation) or accumulate. Potentiallocations for liner plate corrosion are (1) the junction of the containment cylinder andintermediate floors and basemat concrete (PWRs and Mark Ill BWRs), (2) the junction of thedrywell and the base or intermediate concrete floors (Mark I, Mark II concrete containments),(3) adjacent to crane girder rails and supports attached to the liner plate (concretecontainments), (4) water-soaked areas where carbon steel liner plate is used (Mark II andMark Ill containments), and (5) behind insulation and ice-condenser baskets.An amendment to 10 CFR 50.55a became effective September 9, 1996. This amendment,by endorsing the use of Subsections IWE and IWL of Section Xl of the ASME Boiler andPressure Vessel Code, provides detailed requirements for inservice inspection of containmentstructures. Inspection (which includes examination, evaluation, repair, and replacement) ofconcrete containment liner plate in accordance with the 10 CFR 50.55a requirementsinvolves consideration of the potential corrosion areas.This information notice requires no specific action or written response. If you have anyquestions about information in this notice, please contact one of the technical contacts listedbelow or the appropriate NRR project manager.original signed by M.M. SlossonThomas T. Martin, DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical Contacts: Hans Ashar, NRR(301) 415-2851E-mail: hga@nrc.govR. A. Benedict, NRR(301) 415-1157E-mail: rabl@nrc.gov

Attachment:

List of Recently Issued NRC Information Notices*SEE PREVIOUS CONCURRENCEDOCUMENT NAME: 97-10.IN Tech Editor has reviewed and concurred on 11/14/96To receive a copy of this document, Indicate In the box: "C" u Copy without enclosures "E" w Copy with enclosures "N'

• No copyOFFICE ECGG/PECB E C:ECGB l C:PECB D:DRPMNAME HAshar* GBagchi* AEChaffee* 1Martin iRABenedict* <nDATE 11/13/96 11/14/96 01/16/97 03/ 97OFFICIAL RECORD COPY IN 97-xxJanuary, 1997 Corrosion of a liner plate can occur at a number of places where the metal can be exposedto moisture, or where moisture can condense (behind insulation) or accumulate. Potentiallocations for liner plate corrosion are (1) the junction of the containment cylinder andintermediate floors and basemat concrete (PWRs and Mark IlIl BWRs), (2) the junction of thedrywell and the base or intermediate concrete floors (Mark I, Mark II concrete containments),(3) adjacent to crane girder rails and supports attached to the liner plate (concretecontainments), (4) water-soaked areas where carbon steel liner plate is used (Mark II andMark IlIl containments), and (5) behind insulation and ice-condenser baskets.An amendment to 10 CFR 50.55a became effective September 9, 1996. This amendment,by endorsing the use of Subsections IWE and IWL of Section Xl of the ASME Boiler andPressure Vessel Code, provides detailed requirements for inservice inspection of containmentstructures. Inspection (which includes examination, evaluation, repair, and replacement) ofconcrete containment liner plate in accordance with the 10 CFR 50.55a requirementsinvolves consideration of the potential corrosion areas.This information notice requires no specific action or written response. If you have anyquestions about information in this notice, please contact one of the technical contacts listedbelow or the appropriate NRR project manager.Thomas T. Martin, DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical Contacts: Hans Ashar, NRR(301) 415-2851E-mail: hga@nrc.govR. A. Benedict, NRR(301) 415-1157E-mail: rabl@nrc.gov

Attachment:

List of Recently Issued NRC Information Notices*SEE PREVIOUS CONCURRENCEDOCUMENT NAME: G:\RABILINERJIN.REVTo receive a copy of thls document, Indicate In the box: "C's Copy wbhout enclosures "E Copy wkh enclosue "N" -No copyOFFICE ECGG/PECB I E C:ECGB IC:PECB I D:DRPM IIIIIIlIIIlNAME HAshar* GBagchi* AEChafffe MartinLNRABenedict* IW __DATE 11/13/96 11/14/96 jffWm i 2/3 /86q? -12/ /96OFFICIAL RECORD COPY I14/ 1 lhIN

' 'IN 96-xxNovember xx, 1996 the entire gap at the junction with dense silicone elastomer. The repair ofthe pitted areas consisted of (1) welding the pitted areas, (2) examining therepaired areas in accordance with the ASME Section III, Division 2, and(3) recoating the repaired areas.Corrosion of a liner plate can occur at a number of places where the metal canbe exposed to moisture, or where moisture can condense (behind insulation) oraccumulate. Potential locations for liner plate corrosion are (1) thejunction of the containment cylinder and intermediate floors and basematconcrete (PWRs and Mark III BWRs), (2) the junction of the drywell and thebase or intermediate concrete floors (Mark I, Mark II concrete containments),(3) adjacent to crane girder rails and supports attached to the liner plate(concrete containments), (4) water-soaked areas where carbon steel liner plateis used (Mark II and Mark III containments), and (5) behind insulation andice-condenser baskets.An Amendment to 10 CFR 50.55a that became effective on September 9. 1996,endorses the use of Subsections IWE and IWL of Section XI of the ASME Boilerand Pressure Vessel Code, with a few additional requirements, for inserviceinspection of containment structures. Inspection (which includes examination,evaluation, repair, and replacement) of concrete containment liner plate inaccordance with the 10 CFR 50.55a requirements involves consideration of thepotential corrosion areas.This information notice requires no specific action or written response. Ifyou have any questions about information in this notice. please contact one ofthe technical contacts listed below or the appropriate NRR project manager.Thomas T. Martin, DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical Contacts: Hans Ashar, NRR R.A. Benedict, NRR(301) 415-2851 (301) 415-1157E-mail: hga@nrc.gov E-mail: rabl@nrc.gov

Attachment:

List of Recently Issued NRC Information Notices*SEE PREVIOUS CONCURRENCEDOCUMENT NAME: G:\RAB1\LINERIN.REVTo receive a copy of this document, Indicate In the box: "Cab -Copy without enclosures "E' -Copy with enclosures "N" -No copyOFFICE ECGG/PECB I E C:CECGB C:PECB D:DRPMNAME HAshar* GBagchi* AEChaffee TTMartinRABenedi ct*DATE 11/13/96 11/14/96 12/ /96 iB 12/ /96 12/ /96OFFICIAL RECORD COPY IN 96-xxNovember xx, 1996 the junction. The liner plate was found to have pitted significantly (as muchas 50 percent of the original thickness) at various locations along thecircumference. Before the restart of the two Brunswick units, the licenseecleaned the joint areas, repaired the pitted liner plate areas, and resealedthe entire gap at the junction with dense silicone elastomer. The repair ofthe pitted areas consisted of (1) welding the pitted areas, (2) examining therepaired areas in accordance with the ASME Section III, Division 2. and (3)recoating the repaired areas.Corrosion of a liner plate can occur at a number of places where the metal canbe exposed to moisture, or where moisture can condense (behind insulation) oraccumulate. Potential locations for liner plate corrosion are (1) thejunction of the containment cylinder and intermediate floors and basematconcrete (PWRs and Mark III BWRs), (2) the junction of the drywell and thebase or intermediate concrete floors (Mark I, Mark II concrete containments),(3) adjacent to crane girder rails and supports attached to the liner plate(concrete containments), (4) water-soaked areas where carbon steel liner plateis used (Mark II and Mark III containments). and (5) behind insulation andice-condenser baskets.An Amendment to 10 CFR 50.55a that became effective on September 9. 1996,endorses the use of Subsections IWE and IWL of Section XI of the ASME Boilerand Pressure Vessel Code, with a few additional requirements, for inserviceinspection of containment structures. Inspection (which includes examination,evaluation, repair, and replacement) of concrete containment liner plate inaccordance with the 10 CFR 50.55a requirements involves consideration of thepotential corrosion areas.This information notice requires no specific action or written response. Ifyou have any questions about information in this notice, please contact one ofthe technical contacts listed below or the appropriate NRR project manager.Thomas T. Martin, DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical Contacts: Hans Ashar, NRR R.A. Benedict, NRR(301) 415-2851 (301) 415-1157E-mail: hga@nrc.gov E-mail: rabl@nrc.gov

Attachment:

List of Recently Issued NRC Information Notices*SEE PREVIOUS CONCURRENCEDOCUMENT NAME: G:\RAB1\LINERIN.REVTo recelve a copy of this document, Indicate In the box: "C" -Copy without enclosures "E" a Copy with enclosures "N" = No copyOFFICE ECGG/PECB I E C:ECGB C:PECB D:DRPM IINAME HAshar* GBagchi* AEChaffee TTMartinlRABenedict*w.F 4 Ski IN 96-xxNovember xx, 1996 circumference. Before the restart of the two Brunswick units, the licenseecleaned the joint areas, repaired the pitted liner plate areas, and resealedthe entire gap at the junction with dense silicone elastomer. The repair ofthe pitted areas consisted of (1) welding the pitted areas, (2) examining therepaired areas in accordance with the ASME Section III, Division 2, and (3)recoating the repaired areas.Corrosion of a liner plate can occur at a number of places where the metal canbe exposed to moisture, or where moisture can condense (behind insulation) oraccumulate. Potential locations for liner plate corrosion are (1) thejunction of the containment cylinder and intermediate floors and basematconcrete (PWRs and Mark III BWRs). (2) the junction of the drywell and thebase or intermediate concrete floors (Mark I. Mark II concrete containments),(3) adjacent to crane girder rails and supports attached to the liner plate(concrete containments). (4) water-soaked areas where carbon steel liner plateis used (Mark II and Mark III containments), and (5) behind insulation andice-condenser baskets.This information notice requires no specific action or written response. Ifyou have any questions about information in this notice, please contact one ofthe technical contacts listed below or the appropriate NRR project manager.Thomas T. Martin, DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical Contacts: Hans Ashar. NRR(301) 415-2851E-mail: hga@nrc.govR.A. Benedict, NRR(301) 415-1157E-mail: rabl@nrc.gov

Attachment:

List of Recently Issued NRC Information Notices*SEE PREVIOUS CONCURRENCEDOCUMENT NAME: G:\RAB1\LINER IN.REVTo receive a copy of this document, Indicate In the box: "C" = Copy without enclosures "E"

• Copy with enclosures "N"

• No copyOFFICE ECGG/PECB I E C:ECGB lC:PECB D:DRPMNAME HAshar* GBagchi* AEChaffee £ TTMartinRABenedict* fiFDATE 11/13/96 11/14/96 11/ /96 q5SV 11/ /96 11/ /96OFF ICI IN 96-xxNovember xx, 1996 circumference. Before the restart of the two Brunswick units, the licenseecleaned the joint areas, repaired the pitted liner plate areas, and resealedthe entire gap at the junction with dense silicone elastomer. The repair ofthe pitted areas consisted of (1) welding the pitted areas in accordancewith the ASME Section VIII, "Rules for Construction of Pressure Vessels",(2) examining the repaired areas in accordance with the ASME Section III,Division 2, and (3) recoating the repaired areas.Corrosion of a liner plate can occur at a number of places where the metal canbe exposed to moisture, or where moisture can condense (behind insulation) oraccumulate. Potential locations for liner plate corrosion are (1) thejunction of the containment cylinder and intermediate floors and basematconcrete (PWRs and Mark III BWRs), (2) the junction of the drywell and thebase or intermediate concrete floors (Mark I, Mark II concrete containments),(3) adjacent to crane girder rails and supports attached to the liner plate(concrete containments), (4) water-soaked areas where carbon steel liner plateis used (Mark II and Mark III containments), and (5) behind insulation andice-condenser baskets.This information notice requires no specific action or written response. Ifyou have any questions about information in this notice, please contact thetechnical contact listed below or the appropriate NRR project manager.Thomas T. Martin, DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical Contacts: Hans Ashar, NRR(301) 415-2851E-mail: hga@nrc.govR.A. Benedict, NRR(301) 415-1157E-mail: rabl@nrc.gov

Attachment:

List of Recently Issued NRC Information Notices*SEE PREVIOUS CONCURRENCEDOCUMENT NAME: G:\RAB1\LINER-IN.REVTo receive a copy of this document, Indicate In Ul box: 'C' Copy without enclosures "E" Copy with enclosures "N' No copyOFFICE CGG/PECB I E C: l C:PECB D:DRPMOF_ _C _ _ _ _ _ _ _ __g 1 I _ _ __ __ __ _NAME HAshar* gQ AEChaffee TTMartinRABenedict* /K IcDATE 11/13/96 , 11/ M996 611/ /96 11/ /96 11/ /96OFFICIAL RECORD COPY IN 96-xxNovember xx, 1996 circumference. Before the restart of the two Brunswick units, the licenseecleaned the joint areas, repaired the pitted liner plate areas, and resealedthe entire gap at the junction with dense silicone elastomer. The repair ofthe pitted areas consisted of (1) welding the pitted areas, (2) examining therepaired areas in accordance with the ASME Section III. Division 2, and (3)recoating the repaired areas.Corrosion of a liner plate can occur at a number of places where the metal canbe exposed to moisture, or where moisture can condense (behind insulation) oraccumulate. Potential locations for liner plate corrosion are (1) thejunction of the containment cylinder and intermediate floors and basematconcrete (PWRs and Mark III BWRs), (2) the junction of the drywell and thebase or intermediate concrete floors (Mark I. Mark II concrete containments),(3) adjacent to crane girder rails and supports attached to the liner plate(concrete containments), (4) water-soaked areas where carbon steel liner plateis used (Mark II and Mark III containments), and (5) behind insulation andice-condenser baskets.This information notice requires no specific action or written response. Ifyou have any questions about information in this notice, please contact thetechnical contact listed below or the appropriate NRR project manager.Thomas T. Martin. DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical Contacts: Hans Ashar, NRR(301) 415-2851E-mail: hga@nrc.govR.A. Benedict. NRR(301) 415-1157E-mail: rabl@nrc.gov

Attachment:

List of Recently Issued NRC Information Notices*SEE PREVIOUS CONCURRENCEDOCUMENT NAME: G:\RAB1\LINERIN.REVTo receive a copy of thIs document, Indicate In the box: SC" a Copy wihout enclosures "E' -Copy with enclosures "N" -No copy[OFFICE ECGG/PECB I E C: ECGB I :EC D:DRPM IINAME HAshar* GBagchi* AEChaffee TTMartinRABenedict*DATE 11/13/96 11/14/96 11/ /96 11/ /96 11/ /96OFFICIAL RECORD COPY IN 96-xxNovember xx, 1996 the pitted areas consisted of (1) welding the pitted areas in accordancewith the ASME Section VIII, "Rules for Construction of Pressure Vessels". (2examining the repaired areas in accordance with the ASME Section III. Divi on2. and (3) recoating the repaired areas.Corrosion of a liner plate can occur at a number of places where the etal canbe exposed to moisture, or where moisture can condense (behind ins ation) oraccumulate. Potential locations for liner plate corrosion are thejunction of the containment cylinder and intermediate floors a 5basematconcrete (PWRs and Mark III BWRs), (2) the junction of the dr ell and thebase or intermediate concrete floors (Mark I, Mark II concrete containments),(3) adjacent to crane girder rails and supports attached the liner plate(concrete containments), (4) water-soaked areas where ca -on steel liner plateis used (Mark II and Mark III containments), and (5) b nd insulation andice-condenser baskets.An Amendment to 10 CFR 50.55a that became effecti on September 9. 1996,endorses the use of Subsections IWE and IWL of ction XI of the ASME Boilerand Pressure Vessel Code, with a few additiona requirements, for inserviceinspection of containment structures. Inspe ion (which includes examination,evaluation, repair, and replacement) of co rete containment liner plate inaccordance with the 10 CFR 50.55a requir nts involves consideration of thepotential corrosion areas described abo .This information notice requires no ecific action or written response. Ifyou have any questions about inform ion in this notice, please contact thetechnical contact listed below or he appropriate NRR project manager.Thomas T. Martin, DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical Contacts: H s Ashar, NRR01) 415-2851E-mail: hga@nrc.govR.A. Benedict, NRR(301) 415-1157E-mail: rabl@nrc.govAttachment List of Recently Issued NRC Information NoticesDOCUMENT NAME: RAB1\LINERIN.REVTo receive a copy of Is document, Indicate In the box: "C" -Copy without enclosures "E" u Copy with enclosures "N"

• No copyOFFICE EC /PECB l C:ECGB T C:PECB D:DRPMNAME Uyshar a GBagchi AEChaffee TTMartin Il MABenedic Pta~er.lkDATE 11/ /96 11/ /96 11/ /96 11/ /96 11/ /96OFFICIAL RECORD COPY