ML18017B107

Final Deficiency Rept Re Omission of Reinforcing Steel in Reactor Auxiliary Bldg 2 South,Exterior,Shear Wall.Caused by Human Error.Holes Drilled & Bars Grouted Into Previously Placed Concrete.Special Tests Conducted to Validate Repairs

ML18017B107
Person / Time
Site:	Harris
Issue date:	06/04/1980
From:	CAROLINA POWER & LIGHT CO.
To:
Shared Package
ML18017B106	List: ML18017B105 ML18017B107
References
NUDOCS 8006160075
Download: ML18017B107 (9)

Text

SHEARON HARRIS NUCLEAR POWER PLANT~UNIT NO.2 OMISSION OF.VERTICAL REINFORCING STEEL IN REACTOR AUXILIARY BUILDING NUMBER 2 SOUTH, EXTERIOR, SHEAR WALL.Final Report June 4, l980 Reportable Under lOCFR50.55(e)

Prepared by: Carolina Power&Light Company soo6>6o g+~

SUBJECT:

10CFR50.55(e)

Repor table Item Shearon Harris Nuclear Power Plant (SHNPP)Omission of Reinfovcing Steel in Unit No.2 Reactor Auxiliary Building South Shear Wall ITEM: Unit No.2 Reactor Auxiliary Building South, Exterior, Shear Wall SUPPLIED BY: Constructed on site NATURE OF DEFECT: A section of the Unit No.2 Reactor Auxiliary Building South Shear Wall on each side of column F 47 was poured z (concrete placed)with alternate Reinforcing Bars missing on each face in the upper 4'-6" section of the 10'-6" high placement to elevation 201.0.'.A total of 52 bars were missing.DATE PROBLEM WAS CONFIRMED TO EXIST: October 19, 1979 PROBLEM REPORTED: Reported to NRC Region II as"Potentially Reportable" on October 29, 1979 and as"Reportable" on October 30, 1979.SCOPE OF PROBLEM: This Rebav omission was attributable to human error and all investigations into civcumstances surrounding the omission are discussed in detail in the References.

All references are available for review on site and most have been pre-viously transmitted to NRC Region II.SAFETY IMPLICATIONS:

In the unlikely event that this Rebar omission had gone undetected, the reinfovcing steel on the South Face could have been stressed to 95.5 KIPS/square inch and the Novth Face could have been stvessed to 73.4 KIPS/square inch as compared to the design allowable yield stress of 54.KIPS/square inch if the.most severe design basis conditions required to be assumed weve evev encountered.

Calculations are available for review in the New York office of Ebasco Services, Incorporated.

Since the ultimate stress for Gvade 60 Reinforcing Steel is 90 KIPS/square inch and actual user test data for No.11 Bars used on this project are typically 103 to 110 KIPS/square inch, the actual consequences of the most severe design basis conditions assumed would be cracking of the wall in this localized area.REASON(S)PROBLEM WAS REPORTABLE:

The basis for considering this item re-portable is the amount of evaluation, testing and repair work requived to restore the desired safety margin to this localized portion of the structure.

CORRECTIVE ACTIONS: The structure was repaired in accordance with PW-C-983, Rev.1 which required holes to be drilled and bars grouted into previously placed concrete.Special tests were conducted to validate this repair method.Details of these physical repairs as well as administrative and procedural corrective actions are contained in the References.

All References are available for review on site and most have been previously transmitted to NRC Region II.

REFERENCES/CHRONOLOGY 10/19/79 DR 359 DR359 issued identifying 52 bars omitted from RAB No.2 south shear wall.This DR was closed 3/26/80.10/29/79 DDR 311 DDR issued on DR359 to provide vehicle to document evaluation.

CAR completed 4/18/80.10/29/79 Telecon CP&L notified NRC (Bradley)of'Potentially reportable" item-52 bars omitted in RAB No.2 shear wall.10/29/79 10/29/79 10/29/79 10/30/79 DDR 313 Telecon CP&L Letter NRC Letter DDR issued on'CB exteri'or wall vertical bars omitted-CAR completed 4/17/80.Mr.Murphy (NRC)called Mr.McDuffie (CPEL)obtaining concurrence to stop concrete place-ments until investigation and evaluation is completed.

Mr.Smith (CPEL)to Mr.Parsons (CPGL)stopping concrete placements.

Mr.O'Reilly (NRC)to Mr.Jones (CPEL)confirm-ing 10/29/79 telecon between Mr.Murphy and Mr.McDuffie.10/30/79 10/30/79 Telecon Mgmt.Audit CPEL notified NRC (Bradley)that 52 bars omitted from RAB No.2 shear wall was reportable.

CPRL management (Mr.Howe, Mr.Smith and Mr.Chiangi)conducted indepth audit to determine conditions surrounding rebar omission at two locations.

10/30/79 Field Audit, 10/30/79 Field Analysis 10/30/79 Telecon 10/31/79 Meeting CP8L initiated audit of previously placed concrete dowels and documents (DR's, PN's and DDR's).Manpower ratios analyzed to ensure craft-foremen-general foremen-superintendent ratios were acceptable.

Mr.Chiangi (CPEcL to Mr.Bradley (NRC)CPEL (Mr.Howe, Mr.Smith, biz.Lucas)met with NRC in Atlanta to explain details of rebar omissions.

10/31/79 11/1/79 Training CP&L Letter Training sessions conducted on 10/31/79 and 11/1/79 for all site engineers and inspectors to emphasize responsibility of reporting significant nonconforming conditions to super-vision and management.

Mr.Jones (CP&L)to Mr.O'Reilly (NRC)providing"Investigations and Corrective Actions Following Omissions of Rebar at Two Locations".

,11/2/79 11/2/79 CP&L Letter Telecon Mr.Jones (CP&L)to Mr.O'Reilly (NRC)providing"Additional Information

-Investigation and Corrective Actions Following Omissions of Rebar at Two L'ocations".,Mr.Lucas (CP&L)to Messrs.Bradley, Murphy, Lenahan and Conlon (NRC)to discuss fix for RAB No.2 shear wall and CB No.1 exterior wall.ll/2/79 ll/5/79 11/5/79 11/6/79 PN-C-984, Rev.1 CP&L Letter CP&L Letter NRC Letter PW-C-984, Rev.1 issued for CB No.1 exterior wall-implementation completed on 12/3/79.HS-6765 from Hr.Parsons (CP&L)to Mr.Goodman (Daniel)"Quality Accountability of Daniel Personnel".'S-6764 from Mr.Lucas (CP&L)to Mr.Parsons (CP&L)-Documenting Telecon of ll/2/79 with NRC and Related Plan of Action.Mr.O'Reilly (NRC)to Mr.Jones (CP&L)"Confirmation of Concurrence to Place Concrete in Areas Other Than CB No.1 Exterior Mall and RAB No.2 South Shear Hall".11/6/79 11/8/79 11/9/79 11/9/79 CP&L Letter Ebasco Letter CP&L Letter Daniel Letter MS-6771 documenting"Information Session With Construction Inspectors, Area Engineers and Lead Discipline Engineers"-conducted on 10/29/79.EBC-09569"Ebasco Site Visit on 10/30/79".

HS-6781 from Mr.Lucas (CP&L)to Hr.Parsons (CP&L)"Inter in Report-Field Audit of Dowels Partially Embedded in Concrete".

DC-2243 from Mr.Goodman (Daniel)to Mr.Parsons (CP&L)"Daniel Quality Commitment"-documents job wide quality re-emphasis sessions with entire field supervisory organization held 10/31/79 and ll/1/79.

~~

~~~~al 11/9/79 11/12/79 11/14/79 Telecon CP&L Letter NRC Letter Mr.Lucas (CP&L)to Mr.Bryant (NRC)requesting concurrence for test bar in-stallation in RAB No.2 south shear wall.MS-6788 from Mr.Lucas (CP&L)to Mr.Seyler and Hr.Simpson (CP&L)"Investigation of Rebar Omission".

Mr.O'Reilly (NRC)to Mr.Jcnes (CP&L)providing confirmation of concurrence for test bar installation in RAB No.2 south shear wall.11/14/79 11/15/79 11/26/79 11/27/79 Telecon NRC Letter Ebasco Letter Pour Card Mr.Lucas (CP&L)to Mr.'onlon (NRC)-'equested release for CB No.1 exterior wall'concrete placement.

Mr.O'Reilly (NRC)to Mr.Jones (CP&L)releasing concrete placements on CB No.1 exterior wall per ll/14/79 telecon.EB-C-09666"Containment hall Safety Evaluation Report for PM-C-984, Rev.1".Pour Card 2RAGP212001-A and associated inspection reports documents installation (grouting) of test bars in RAB No.2 south shear wall.ll/28/79 12/5/79 CP&L Letter CP&L Letter QA-1386 documents telecon to NRC declaring missing CB No.1 exterior wall missing bars as"not repor table".Mr.Chiangi (CP&L)to Hr.O'Reilly (NRC)"Interim Report on RAB No.2 South Shear (lail.12/28/79 1/8/80 2/13/79 2/14/80 Technical Report PN-983, Rev.1 CP&L Letter CP&L Letter"Reactor Auxiliary Building Unit No.2 Reinforcing Bar Pullout Test"-required by PN-C-983.RAB No.2 South Shear Mall Dowels-closed/implemented 4/1/80.Hr, HcDuffie (CP&L)to Mr.O'Reilly (NRC)submitted technical report"Engineering Evaluation and Repairs for Reactor Auxiliary Building No.2 South Shear Mall"-PN-C-983, Rev.1 Hr.Jones (CP&L)to Mr.O'Reilly (NRC)"Engineering Evaluation and Repairs for Reactor Auxiliary Building No.2 South Shear Hall and Containment No.1 Exterior Hall".

~Ea.~~

0 V w 2/18/80 2/29/80 3/7/80 3/12/80 CP5L Letter CPEL Let,ter Pour Card Pour Card Mr.Jones (CPhL)to Mr.O'Reilly (HRC)submitted results of RAB No.2 pull test of grouted bars and requested concurrence of repair method.Mr.Chiangi (CP&L)to Hr.O'Reilly (NRC)notified NRC of revised date for completing corrective action on RAB No.2.2RAGP212001 pour card for grouting RAB No.2 dowels.2RAGP212002 pour card for grouting RAB No.2 dowels.