ML19262A632

Final Deficiency Rept Re 781213 Concrete Void Beneath Equipment Batch Reactor Bldg.Void Repaired on 790709 by Placing Grant Between New Concrete & Liner

ML19262A632
Person / Time
Site:	Wolf Creek
Issue date:	09/25/1979
From:	KANSAS GAS & ELECTRIC CO.
To:
Shared Package
ML19262A631	List: ML19262A630 ML19262A632
References
NUDOCS 7912070175
Download: ML19262A632 (4)

Text

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REPORT OF CONCRETE VOID, This final report is mado pursuant to 10CFR50.55(e) regarding a concrete void under the equipment hatch in the Wolf Creek Reactor Building.

(a) DESCRIPTION OF THE DEFICIENCY On December 13, 1978, when the forms for the sixth ring pour of the Wolf Creek Reactor Building were raised, a void beneath the equipment hatch was revealed.

The void the equipment hatch extended about 2 feet downward from the bottom of centerline. The width of the void was approximately six feet and the depth extended through the thickness of the wall, which is approximately eight feet.

(b) IDENTIFICATION OF THE FIRM CONSTRUCTING THE PACILITY Concrete placement for all Power Block Buildings at Wolf Creek is performed by Daniel International.

(c) ANALYSIS OF SAFETY IMPLICATIONS 9

it Because of the dimensions and location of the void described above, is impossible that the void could remain unseen and thus remain unre-paired until the structure would go into service. However, if it is postu-lated that the void remained undetected, it would have most probably been detected at the time of tendon tensioning (which occurs prior to operation) because of axcessive deformations as a result of tendon load. Repair of the void will meet all design requirements and no adverse effect to the health and safety of the public will result because of this void. .

(d) A DESCRIPTION OF THE CORRECTIVE ItCTION, ORGANIZATION RESPONSIBLE FOR THE isCTION, AND MEASURES TO PREVENT RECURRENCE The void was documented on Daniel Nonconformance Report 1SN0719C and forwarded to the Architect / Engineer, Bechtel Power Corporation, for evalaation and disposition. Before proceeding with the repair work, details of the repair were approved by the Architect / Engineer and sent to NRC Region Il personnel for review and concurrence.

A5 ' by 8' section of the equipment hatch liner was removed to facilitate the removal of unsound concrete and the placemen't of new concrete. Some localized areas which were near the void but underneath the remaining equipment hatch liner alse became suspect. A second nonconformance report NCR ISUO853C was initiated to document the possible existence of additional voids. Obse vation holes were drilled but, upon inspection,'no such voids were found and this non-conformance report was closed. On May 31, 1979, concrete was placed into the void area and later the cutout section of the hatch liner war welded back into position. -

On July 9, in accordance with the approved repair disposition, grout was placed between the new concrete and the liner utilizing two 7" dieneter stand-pipes to provide a head pressure. The grout.was agitated until it flowed from each of eleven 3/4" vent holes. None of the observation, standpipe, or vent holes were located in the part of the liner which will serve as the

" pressure boundary" for the containment buildin,, . After the grout was set, the standpipes were removed and fill plates welded into the standpipe holes.

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Nonconformance Report ISN0719C was closed on July 25 af ter completion of the above repair, which was performed by Daniel International. The ability of the Reactor Building to perform its designed function has not ocen, adversely affected by the void and subsequent repair.

To prevent recurrence of similar deficiencies, a Daniel ad hoc committee was formed to address the points that were described in Mr K V Seyfrit's letter to Mr G L Koester, dated December 19, 1978. A total of 10 recommendations were subsequently developed to provide improved control of future concrete placements.

These ten recommendations nave been been implemented as follows:

RECOMMENDATION 1 Implement a formal program for training responsible personnel in project procedural requirenents.

IMPLEMENTATION 1 The Daniel Wolf Creek department managers have developed and implemented an upgraded program for the training of project personnel in the requirement of the procedures applicable to their jobs. This program encompasses concrete placement activities as well as all other activities affecting quality.

RECOMMENDATION 2 Provide additional training in concrete placement and consolidation require-ments to applicable construction and quality control personnel to assure their knowledge for placing and consolidation of concrete.

IMPLEMENTATION 2 All const ruction supervision involved in concrete activities were trained in Daniel Procedure WP-IV-lO6 (Concrete Pre-placement, Placement, and Post-placement) .

Gang-box sessions were held for the additional training of con-crete craft labor.

RECOMMENDATION 3 Assign a Technical Superintendent-Concrete for the project to direct con-struction personnel in preplanning their work.

IMPLEMENTATION 3 Daniel Procedures AP-II-02, WP-IV-106, and QCP-IV-106 have been revised to incorporate the position of the Technical Superinter. dent-Concrete, The person filling this position reports directly to the Cons _ruction Manager and is responsible for reviewing concrete pours prior to placement and pre-paring special instructions to aid concrete placement personnel.

RECOMMENDATION 4 QC management should conduct regularly scheduled meetings with their sub-ordinate supervision to discuss work forecasts and potential and real problem areas.

Also, QC maaagement should be required to participate in project planning meetings.

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. IMPLEMENTATION 4 The QC Manager holds weekly meetings with the Discipline QC Engineers to discuss forecasts, audit findings, trends, and other areas relating to their responsibilities. This information is passed on to supervisors by the Discipline QC Engineers during regularly scheduled meetins. Representativer from the QC department attend the project planning meetings, which are held each week.

RECC:"ZNDATION 5 Revise WP-IV-lO6 and QCP-IV-106 (Concrete Preplacement, Placement and Post-placement) to address preplanning and special written instructions for difficult concrete placement activities.

IMPLEMENTATION 5 WP-IV-106 was revised to include the details of preplanning and preparation of special written instructions by the Technical Superintendent-Concrete. QCP-IV-lO6 was revised to catablish lines of commun. ation between QC and the Technical Superintendent-Concrete.

RECO:O'ENDATICN 6 A Quality Assurance audit of on-going training of craf t personnel should to conducted in the near future.

IMPLE!SNTATION 6 Daniel QA performed an audit of the training of craft personnel on January 29, 1979. KGLE QA has since audited this training twice and found implementation of the program to be adequate.

RECO:CiENDATION 7 Additional special formal and informal training for craft personnel should be conducted and documented as specifi ed by the Technical Superintendent-Concrete.

IMPLEMENTATION 7 Gang-box training sessions are being conducted with the concrete placing /

and curing personnel by the Technical Superintendent-Concrete and the Concrete Superintendent. The persons who will make the placement use this session to view the difficult areas and ask any questions they may have regarding the place- '

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ment. These meetings are documented by the signatures of the re ponsible foremen on copies of the special instructions which require this type cf training.

RECO:0:ENDATION 8 s

The Project Manager and the Regional Manager, Power Group should neet

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with QC personnel te reaffirm their independence and authority.

IMPLEMENTATION 8 The Project Manager and the Regional Manager, Power Group, held a meeting with site Quality Control personnel on January 24, 1979 and re-affirmed the ,

independence and authority of the QC department. This meeting was documented and is part of the QC department personnel training record.

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RECO:OiENDATION 9 Add to the Daniel Quarterly Quality Assurance Committee Meeting Agenda an item to review the independence and authority of the QC department. This meeting is a joint meeting between KG&E and Daniel.

IMPLEMENTATION 9 The independence and auti.ority of QC has been discussed and confirmed by Daniel and KGEE Management at dhe Daniel QA Committee meetings of February 15, June 6, and September 12, 1979.

RECC i'ENDATION 10 Suhmit formal requests to the Architect / Engineer when required to facilitate placcment of concrete.

IMPLE GNTATION 10 Field Change Requests (FCR 's) or Construction Variance Requests (CVR 's) have been submitted to the Architect / Engineer when changes were needed to facilitate the placement of concrete. This is now a procedural requirement of WP-IV-106.

CONCLUSION The implementation of the committee's recommendations were verified through audits oy the Daniel and KG&E Quality Assurance Deparbments. After KG&E verification, Work Hold Agreement #03, which suspended all safety related concrete placement, except for repair of the void, was released on March 5, 1979. Concrete placement resumed in all buildings except the Reactor Building, which was placed on hold by Werk Hold Agreement #05 because of NRC questions regarding the strength of the Reactor Building basemat concrete. On March 8, 1979, Stop Work Order #04 was issued when it was determined that concrete crews had failed to exactly follow the placing instructions that had been provided by the Technical Superintendent-Concrete.

ment.

The Technical Superintendent-Concrete '.as not present during tne place-This Stop Work Order was released on March 22 after extensive retraining of craf t personnel and replacement of the Concrete Superintendent and Technical Superintendert-Concrete. On July 16, after resolution of the basemat issue, Work Hold Agreement #05 was released and concrete placement was resumed in the Reactor Building.

July.

An audit was performed by 2GSE QA on concrete placement activities during The audit determined that the quality program for the proper placement and consolidation of safety related concrete is adequate and is being effectively implemented. In addition, on-going surveillances are being made of individual concrete pours.

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