ML20084L148
| ML20084L148 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 05/04/1984 |
| From: | Hall D ILLINOIS POWER CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 55-84-03, 55-84-3, U-10151, NUDOCS 8405140359 | |
| Download: ML20084L148 (4) | |
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/LLINDIS POWER 00MPANY U-10151 CLINTON t ER STATION, P.O. BOX CLINTON, ILLINOIS 61,727 g
May 4, 1984-m a
b 4-Doc,ket No. 50-461 a, g s
Mr. Jahee G. Keppler i
Regional Administrator N
Region III;
U.S. Nuclear Regulatory Codblissior.
s 799 Roosevelt Road Glen Ellyn,, Illinois 60137
(
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Subject:
.Potentialk'1CFR50.55(e) Deficiency 55-84-03 Installatian of ConcLet e Expansion Anchors
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Dear Mr. Kepples.:
i On January 11, 1984, Illinok.sPower,Companynotified Mr. R. C. Knop, NRC Region III (ref:
IP memorandum Y-18981 dated January 11, 1984) of a potentially, reportable def,1cieticy, per 10CFR50.55(e) concerning the improper installation of concrete expansion anchor bolts at Clinton Power Stat'idn (CPS).
This initial notification was followed by one (1) interim report (ref:
IP letter U-10123, D. P. Hall to J. G.4Keppler dated February 14,
-1984).
Our investigation of this issus cogtinues,- and this
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letter represents an interim report in acccrdance with 10CFR50.55(e), to keep you informed of our progress.
Statement of Potentially Reportable Dbficiency Irregularities were identified in the methods of installing concrete expansion anchors (CEAs) at CPS.
These> irregularities include welded anchors, embedment depth, and foreign material in the anchor bolt holes.
An evaluation ofsthis issue is being performed to determine the extent of these problems, and their significance on' the safety of operations ap CPS.'
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l Investigation Results/Backgro'und During an Institute of Nuclear Power Operations (INPO) evaluation of CPS construction' activities in late November 1983, irregular-ities were identified in the installations of CEAs by the contractor, Baldwin Associates (BA).
Asia result of these irregularities, Illinois Power directed BA to cease the installation of CEAs until appropriate corrective action was h
8405140359 840504 h
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Mr. Janes G. Koppler May 4, 1984 established and implemented.
In early December, 1983, a concern was received by IP that a CEA installation aerformed by a particular craftsman on a pipe hanger assembly was improper.
Investigation of the installation found that three of four anchors were improperly installed.
Further investigation of all known, totaling forty-nine (49), CEA installations performed by t
the craftsman identified additional examples of improper installation.
Fifteen (15) Ncaconformance Reports (NCRs) have been written to document and obtain resolution of the identified hardware irregularities.
A reinspection plan has been established and implemented at CPS to further investigate the extent of the problem.
This plan initially includes a reinspection of a sample of completed safety related, seismic pipe support CEAs installed by BA prior to the departmental hold, to provide at least a 95% confidence level that less than 5% defects exist in the installations.
The a reinspection sample population is randomly chosen and population size is based on Military Standard 105.D.
Sample reinspections of other disciplines' CEA installations will also be performed as part of_the investigation of this issue in accordance with a plan i
being developed.
A method of reinspecting CEAs that does not require anchor plate removal was developed, qualified, and approved in April, 1984.
The reinspection program is designed to verify:
1.
Anchor _ length 2.
Anchor not welded to plate 3.
Anchor not bent 4.
Diameter of anchor hole not excessively large 5.
No foreign material in anchor hole 6.
Anchor will successfully carry design loads One randomly selected anchor per assembly in the sample population is being reinspected.
If the anchor fails, the remaining anchors are reinspected to support an engineering evaluation of the overall assembly.
As of May 2, 1984, one hundred eighty-six (186) of the total sample population of two l
hundred ninety (290) pipe support CEA assemblies have been reinspected, and resulted in the issuance of twenty (20)
Ncnconformance Reports.
Evaluation of these twenty (20) NCRs is presently underway and has indicated that some NCRs are due to conservatisms in the reinspection procedure and not due to l
deficient installations.
Completion of the pipe support reinspection is scheduled for May 25, 1984.
t Corrective Action (Interim)
Evaluation of the above issue identified several root causes resulting in the identified irregularities:
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Mr. Jam s G. Keppler May 4, 1984
- In-process Quality Control-(QC) inspections were not performed to identify CEA installation irregularities.
-The~following corrective actions have been taken to correct the
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identified causes of this issue and to prevent recurrence _of inadequate CEA installations:
1.
.Baldwin-Associates Procedure BAP 2.16 and Quality Control Instruction QCI-105 have been revised to incorporate several in-process QC inspections and QC hold points.
~2.
BA craftsmen and QC personnel involved in CEA installation are receiving. documented training in the requirements of the anchor bolt installation specification and applicable procedures.
3.
BA craftsmen are now being' qualified prior to being allowed to install CEAs.
Qualification is based upon receiving training to the requirements of CEA specification and procedures.
~4.
A departmental hold on CEA installation by BA was.placed in effect at CPS on November 29, 1983.
The hold was lifted on January 6, 1984, after the initiation of the corrective actions identified above.
5.-
A reinspection of all CEAs known to be installed by the suspect craftsman was-performed, and irregularities noted by the reinspection were documented on Nonconformance Reports (NCRs).
Resolution of-these NCRs will assure that the nonconforming installations meet design requirements.
.6.
A reinspection plan has been developed and is'being'imple-mented'to-determine'the extent of CEA installation irregularities, and to re-establish. confidence in past CEA work.
Safety-Implications / Significance
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The Architect / Engineer, Sargent & Lundy, has evaluated the fifteen (15) NCRs resulting from the investigation of the craftsman'.s installation, and determined that none of the conditions, if uncorrected,~would'have adversely impacted the safety of operations of CPS.
Only one (1)oof the twenty (20)
.NCRs written as a result of the sample reinspections of pipe supports has been evaluated to date, and it was also determined Lthat!no adverse impact on safety _resulted from the condition.
7 The remaining nineteen (19) NCRs, as'well as any additional NCRs written'as_a result.of this investigation, will be similarly evaluated.
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Mr. Jcm2s G. Keppler May 4, 1984 Illinois Power Company's investigation of this potentially reportable deficiency is continuing.
It is expected that approximately six (6) months will be necessary to complete the investigation and to file a final report on the issue.
Illinois Power Company intends to provide you an update on the investigation in approximately ninety (90) days.
We trust that this interim report provides you sufficient background information to perform a general assessment of this
_po entially reportable deficiency and adequately describes our t
approach to resolve this issue.
Sincerely yours, D. P. Ha l
Vice President r
RDW/ lag cc:
NRC Resident Office Director, Office of I&E, USNRC, Washington, DC 20555 Illinois. Department of Nuclear-Safety INPO Records Center i
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