ML19284A700
| ML19284A700 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 03/07/1979 |
| From: | Gerstner W ILLINOIS POWER CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| U-0090, U-90, NUDOCS 7903150217 | |
| Download: ML19284A700 (4) | |
Text
i U-0099 lil/NGIS PUlVER CUA1PANY Lt4 79(93 07).9
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March 7, 1979 Mr. James G. 1;eppler Director, Region III Office of Inspection and Enforcement U.
S.
Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Dear Mr. Keppler:
Clinton Power Station Unit 1 Docket No. 50-461 Construction Pernit CPPR-137 On February 1, 1979, Illinois Power Company verbally notified Mr.
T. Vandel, NRC Region III, of a potential reportable deficiency per 10CFR50. 55 (e) (1) (iii).
We have since conducted an investigation as summarized in the attached report and all defective welds have been repaired.
Because of the high cost of detailed engineering analysis, it has not been determined that the welding defects were serious enough to classify them as reportable.
We have been advised by S&L that--
in their j udgment, if such an analysis were made--there is no reason to believe that a hazardous condition would have been found to exist.
Since all welds have been repaired, the results of such an analysis uoulc be academic and we do not propose to pursue the matter further.
'?e trust that the information provided in the attached report is sufficient for your analysis and evaluation of the deficiency and the corrective action.
Additional details obtained during the inves-tigation are available in our files.
Sincerely, T'
s W
C.
Gerstner Executive ' lice President J UG : GEW.j ?
cc:
Director, Office o f I&E, s'RC,
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C.
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790315 0 A / 7 5
s Attachment to U-0090 Ll4-79(03-07)-9 Page 1 of 3 Report on Constructic.- Deficienc; Clinton Petter Static-Jni: 1 Dry ell Wall P l a : cw o r'<
(per 10CFR50.53(-
(3,,
peficiency - (per 10CFR50. 55 (e) (1) (it:
As the result of a QA audit of radicgraphic records for the Clinton Power Station Unit "I lower drr: ell call platework field welds, seventeen (17) areas tha: vers presicusly accepted were identified that did not acet AS::E code requirements.
These linear indications and slab inclusicas vere scattered randomly throughout the field welds and totaled less than thirteen inches in length.
Sargent and Lundy, the cesigner, reviewed the indi-cations and concluded that three (3) cf the areas did not require repair and that an exhaustive engineering analysis of the remain-ing fourteen (14) indications would be recuired to determine their impact on the structural integrity of the drywell wall.
- However, it was estimated that the cost of an engineering analysis might vell exceed the repair costs and, therefore, a management decision was made to forego the analysis and proceed with the repairs.
The chronology of events leading up tc notifying the NRC on 2/1/79 that a potential reportable deficienc:. (10CFR50.55e) was being investigated relative to the lower cry': ell wall platework is as follows.
During Baldwin Associates' QA Audit I-ll2, " Mechanical Fabrication /
Installaticn" (performed 1/16-19/79), a randomly selected sample of radiographs were reviewed.
These radiographs were selected from completed Icuer drywell wall platercri traveler packets.
The radio-graphs were reviewed for the audit :ecn by Ealdwin Associates' Technical Services Senior NDE Engineer a Level II interpreter.
During the review, five (5) indications were founc which were opined to be outside the acceptance limits as defined in the specified ASFI code (Section III, NB-5000 of the 197-Edition with Summer '75 addenda).
When these indications were found, two Baldwin Associates' Level III interpreters were consulted and they agreed that the indi-cations did not meet code requirements, In an effort to determine if this was an isolated case, a second' random selection of radiographs was re. ewec.
This group of radio-graphs contained one additional unacceptable indication.
Based on these findings, a decision ras made to reciev all radio-graphs associated with the drywell n11 traveler nackets, over si:cteen hundred (1600) shots including repairs.
This review was performed by two (2) Level II and t
'2) Lecel III interpreters
4 Attachment to U-0090 Ll4-79 (03-07)-9 Page 2 of 3 during the veck of 1/22-26/79.
A t tal of seventeen (17) un-acceptable indicationn were found ir :.:el.c (12) telds as a result of the total effort, On 1/29/79 a Level III interpreter of :he architect-engineer, Sargent and Lundy, reviewed the radi graphs of concern and con-curred with the findings of Balduin A5 cciates' interpreters.
Nonconformance Report No. 1810, dated 1/3C/79 was initialed and submitted to Sargent and Lundy for di.sposi:icning.
In a letter dated 2/6/79 Sargent and Lundy reported that three (3) of the indications were acceptable for "use-as-is", but that the remain-ing fourteen (14) should be repaired.
Subsequently, in a letter dated 2/20/79 Sargent and Lundy provided their basis for accept-ance of the three areas not repaired.
An inspection team from NRC RO III visited the CPS site 2/6-9/79.
During this visit, team member Carl Erb reviewed the radiographs, the nonconformance report disposition, and the proposed repair procedure.
Mr. Erb was also of the opinica that the indications were unacceptable and commented on the intended repair procedure, which was revised to incorporate his recommendation.
Corrective Action Repair work started on 2/12/79.
In each case, the defect (s) was (were) found, removed, and the re-welds satisfactorily made.
All repairs were completed by 3/2/79.
Ir addition to the direct re-pairs, other corrective action being :aken co assure continued compliance to regulatory requiremen:t incluces:
1.
Bald *.:in Associates will continue its on-going audit pro-gram in a sequence which involves work being installed during its time frame pricr to ecmpletion.
2.
NDE Level III personnel will provide timely audits of radiographs submitted for final record.
3.
NDE Level II personnel will be trained in the detection of defects uncovered as a result of an audit and instruc-tion uill be provided to ch: in ~1evel III assistance in the interpretation on questionable radiographs.
Attachment to U-0090 a
Ll4-79 (0 3-07)-9 Pas;e 3 of 3 Safety Imulications
't h e corrective act Lon:, for the def.'icienc~
=nure no unsafe itu tallation exists,
Because a detailm: en Sneering analysis wa, not performed the significance c f n':.; de fi ciency to the safety of the plant has not been quantified The total length of the unacceptable welds amounted to less than one-tenth of one percent (40.1%) of the field welds.
ybe repairs required for the 14 areas have not been extenstze.
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