ML19257C577
| ML19257C577 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 01/24/1980 |
| From: | KANSAS GAS & ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML19257C568 | List: |
| References | |
| NUDOCS 8001290425 | |
| Download: ML19257C577 (4) | |
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I!JTERI.M REPORT Ct1 CC:JCPETE BLOCK WALLS FOR WCLF CPEEK GENEPATII;G STATIC!!, U!!IT NO. 1 KA'ISAS GAS AND ELECTRIC COMPANY Wichi ta, Kansas 182f 328 Januar'f 24, 1980 s 00129 0 YcP 5
TABLE OF CCf;TE!JTS 1.0 Introducticn 2.0 Description of Deficiency 3.0 Chronology of Events 4.0 Analysis of Safety Implications 5.0 Caure and Corrective Action 5.0 conclusions 1827 329
1 of 2 1.0 INTRCDUCTICN In compl iance with Fegula tion 10CFR50. 55 (e), this Interim Report is being issued because of deficiencies found in the construction of certain concrete block walls erected in the control building of the Wolf Creek Generating Station.
2.0 CE3CRIPTICN OF DEFICIENCY Certain internal walls erected by Daniel International, the Constructor for the Wolf Creek Generating station, in the cc.ntrol building are designed to be constructed with precast masonary units (CMU) which contain reinforcing steel.
Block cells which contain reinforcing steel are grouted. Construction forces did include the reinforcing steel and grout required by the design drawings but failed to position the reinforcing outward toward the faceshell of the CMU as shown on the drawing details.
3.0 CHFCNOLCGY OF E"ENTS In the weeks prior to mid December, 1979, interior CNU walls were erected in the control building on elevations 2032', 2016',
2000' and 1984'.
The construction forces became aware cf the deficiency described above, documented the problem on Non-conformance Peport INN-1536-C and forwarded the report to the Architect Engineer (Bechtel) for evaluation and dispnsition on December 17, 19'3.
All block walls designed to withstand the design basis seismic event which had been erected were included on this NCR.
Bechtel has not yet completed their evaluation of the deficiency but their initial judgment rendered on January 10, 1980, is that a portion of the nonconforming walls are unacceptable.
4.0 ANALYSIS CF SAFETY IMPLICATICNS The nonconforming walls are located adjacent to safety related equipment.
Because of this proximity to safety related equipment the walls are designated seismic Category I and are designed to withstand the safe shutdown basis earthquake.
Failure to locate the reinforcing properly within the wall reduces the ability of the walls to withstand seismic forces.
The ability or inability of the specific walls in question to withstand seismic forces is being dete rmined analytically. The failure of these walls could damage adjacent safety related equipment such that safe shutdown capability would be impaired.
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2 of 2 5.0 CAUSE AND CORFECTIVE 7 CTION The nisplacement of the rebar within the CMU cells was due to lack of proper interpretation of drawing details, lack of understanding of the importance of the block walls and to incomplete inspection by Daniel field engineers. Pending im-plementaticn of new procedures all seismically designed block walls will receive increased surveillance by Daniel's CA Fersonnel, and Daniel supervision has instructed the field forces that walls shall not be grouted until a field engineer has insnected the wall and signed the grout placement card.
The new procedure being developed will establish a fo rmal inspection hold point when a wall, or part of a wall, is ready to be grouted. The inspection will include cell cleanliness, rebar size and rebar location within the coll.
The inspection record will be signed by the Engineer nakinc the increcticn and will be naintained as a record.
This procedure will be implemented by February 29, 1980.
6.0 CC"CLU5 IONS Final conclusions regarding this problem cannot he made until engineerina analysis is conpleted.
Final conclusions will he presented in the final report.
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