ML19338E228
| ML19338E228 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 09/05/1980 |
| From: | Fiorelli G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Gerstner W ILLINOIS POWER CO. |
| References | |
| NUDOCS 8009250252 | |
| Download: ML19338E228 (1) | |
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L Docket No. 50-461 Docket No. 50-462 Illinois Pcver Company ATTN:
Mr. W. C. Gerstner Executive Vice President 500 South 27th Straet Decatur, IL 62525 Gentlemen:
Thank you for your letters dated July 28, 1980 and August 15, 1980, pursuant to 10 CFR 50.55(e) regarding RER heat exchanger lateral support provisions. Per telephone conversation with your staff on August 22, 1980, it is our understanding that additional stiffeners and supports will ba installed to meet the original design criteria. We will complete our review of this matter during a future inspection.
Your cooperation with us is appreciated.
Sincerely, C. Fiorelli, Chief Reactor Construction and Engineering Support Branch ec: Director, RCI/II Director, AEOD Chief, OEB/MPA IE Files cc w/lcra dtd 7/28/80 & 8/15/80:
Central Files FDR Local FDR ESIC Mr. Dean Hansell, Office of Assistant Attorney General Mr. Gary N. Wright, Chief Division of Nuclear Safety 8009250.252 3
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N%c Form J10A (R M) (5 76) NRCM 02040 U. S. GOVERNMENT PRINTING OFFICE: 1979-289-125
hb U-0166 Ll4-80(08-15)-9 ILLINDIS POWER COMPANY I*n 500 SOUTH 277H STREET DECATUR, ILLINOIS 62525 August 15, 1980 Mr. James G. Keppler Director, Region III office of Inspection and Enforcement U.S. Nuclear Regulatory Cormtission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Dear Mr. Keppler:
Clinton Power Station Unit 1 Docket 50-461 Construction Permit CPPR-137 This letter amplifies Illinois Power Company's letter of July 28, 1980, which reported a deficiency under the provisions of 10CFR50.55 (e), concerning RHR heat exchanger lateral support provisions.
The statement in paragraph two of the Corrective Action section, " Subsequently, the repairs were made,", was misleading and requires amplification to fully and accurately explain the actions that were taken, The engineering solution selected to correct this non-con-forming condition involved redesign of the' lateral support steel connection details, It did not require changc of the embeds which were undersize.
Therefore, the " repair" of the undersize embeds consisted of a design change to the support steel, At the time of the July 28, 1980 report, the design change of the attachments had been made, and the repair" of the undersize embed.s was complete.
However, it would have been more correct to have stated " Subsequently, redesign of the. attachments was completed."
The action to correct the reported w.de:cize e beds will con-form to the revised design of the lateral support system for the RHR Iteat exchangers. The undersize embeds will not be changed, ly, m
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L14-80(08-15)-9 Jam]s G. Kapplar Auguct 15, 1980 We trust that this amplifying information is satisf actory and will permit completion of your analysis and evaluation of the deficiency and corrective action.
Sincerely, L
. Koch Vice* President-Director, Office of I&E, NRC, Washington D.C.
cc:
H. H. Livermore, NRC Resident Inspector
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/LLINDIS POWER COMPANY W*
L14-80(07-28)-9 I 500 SOUTH 27TH STREE7. DECATUR. ILUNOIS 62525 July 28, 1980 Mr. James G. Keppler Director, Region III Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission 799 Roosevelt Road 11en Ellyn, Illinois 60137
Dear Mr. Keppler:
References:
(1) Illinois Power Company letter U-0148, 6/13/80, L. J. Koch to J. G. Keppler, NRC Region III:
" Extension of Time for 10CFR50.55(e) Final Report" (2) Telephone communication on 7/1/80, G. E. Wuller (IP) ahd H. M. Wescott, NRC Region III;
" Additional Extension Request for Final Report" Clinton Power Station Unit 1 Docket No. 50-461 Construction Permit No. CPPR-137 Illinois Power Company has determined that the referenced potential reportable deficiency is reportable as per 10CFR50.55(e) (iii).
We have conducted an investigation in this matter and herewith submit our final report concerning the RHR heat exchanger lateral support provisions.
Investigation of Incorrect Embed Plates for RHR Heat Exchaneer Lateral Support 1.
Statement of Reportable Deficiency Eight carbon steel plate embeds cast in the concrete structure surrounding the RHR heat exchangers were discovered to have plate thicknesses less than that indicated on the drawings and required by the design.
Two of these embeds were also mislocated.
2.
Investigation Results During installation of the lateral supports for the RHR heat exchangers located in the Auxiliary Building, it was discovered that two of the eight embed plates had been mislocated in elevation by half of a plate width (top edge of the plate had been set at the desired elevation instead of the center line of plate).
Nonconformance "eport (NCR) 2959 was written for AUS 41980 D
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U-0162 L14-80(07-28)-9 James G. Keppler July 28, 1980 Page 2 these mislocated embeds, cast into the 110 line wall, when connection of the lateral support steel could not be made.
Disposition of NCR 2959 required that the concrete above the two plates be chipped down to a depth of one inch.
New one-inch thick plates were to be bolted to the concrete wall and welded flush to the edge of the existing mislocated embed plates.
During the chipping operation, it was discovered that the exist-ing plates were only one-half inch thick, not one inch thick as expected.
At this point, it was realized that these two and the other six embed plates were of the wrong size.
NCR 3207 was written documenting this nonconformance.
Subsequent study of the drawings revealed that a moment resist-ing connection had been designed for the lateral support i
structural steel members rather than the customary framed beam connection (simple support).
It had been assumed by both the contractor's personnel performing the take-off and installing the plates, and the QA instructors checking the installation prior to the concrete pours, that standard framed beam connections were to be used at these eight locations.
Both failed to notice the note on the design drawing calling for non-standard embeds.
The QC inspectors also missed the details called out on the applicable inspection checklists.
3.
Corrective Action The General Electric Company was contacted to de*: ermine what the effect would be to have a less rigid lateral support system than specified for the RHR heat exchangers.
According to General Electric Company, considerable time wou*.d be required to determine the significance of this error.
Therefore, as a practical matter, we assume the deficiency to be significant i
enough to be reportable, rather than stand the cost of a detailed and time-consuming engineering analysis.
Illinois Power Company has directed that the rework restore the RHR lateral support system to the stiffness specified by the General Electric Company's established criteria.
Subsequently, the repairs were made.
To provide assurance that this embed installation / inspection
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error was an isolated occurrence, a population of non-standard embed plates was selected for reinspection.
Inspection
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results have confirmed that this was an isclated instance, i
To avoid recurrences of a similar nature, additional instruction j
has been provided to appropriate construction supervisory and r
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U-0162 Ll4-80(07-28)-9 James G. Keppler July 28, 1980 Page 3 QC inspection personnel.
The requirements for accuracy in adhering to design details and inspection criteria have been stressed.
We trust that the information provided in this final report is sufficient for your analysis and evaluation of the deficiency and the corrective action.
i Sincerely, L. J. Koch Vice President di Director, Office of I&E, NRC, Washington, D.C.
cc:
H. H. Livermore, NRC Resident Inspector
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