ML20092L254

Final Deficiency Rept 55-82-09 Re Small Bore/Instrumentation Piping & Conduit Support Design Calculations.Initially Reported on 820902.Sargent & Lundy Procedures for Small Bore/Instrumentation Support Design Corrected & Clarified

ML20092L254
Person / Time
Site:	Clinton
Issue date:	06/15/1984
From:	Hall D ILLINOIS POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
1605-L, 55-82-09, 55-82-9, U-10143, NUDOCS 8406290300
Download: ML20092L254 (6)

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1605-L ILLINDIS POWER COMPANY y U-10143 CLINTON POWER STATION. P.O. BOX 678. CLINTON. ILLINOIS 61727 June 15, 1984 Docket No. 50-461 Mr. James G. Keppler Regional Administrator Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Subject:

Potential 10CFR50.55(e) Deficiency 55-82-09 Small Bore / Instrumentation Piping, and Conduit Suprort Design Calculations

Dear Mr. Keppler:

On September 2, 1982, Illinois Power notified Mr. P. Pelke, NRC Region III (Ref: IP memorandum Y-13910, 1605-L, dated September 2, 1982) of a potentially reportable deficiency con-cerning discrepancies identified by Illinois Power in a sample of small borc/ instrumentation piping support design calculations performed by Sargent & Lundy (CPS Architect-Engineer). This initial notification was followed by six interim reports (Ref:

IP letter, D. P. Hall to J. G. Keppler, U-0555, dated October 1, 1982; IP letter, D. P. Hall to J. G. Keppler, U-10014, dated December 21, 1982; IP letter, D. P. Hall to J. G. Keppler, U-10040, dated March 28, 1983; IP letter, D. P. Hall to J. G.

Keppler, U-10071, dated July 6, 1983; IP letter, D. P. Hall to J.

G. Keppler, U-10099, 1605-L, dated September 30, 1983; and IP letter, D. P. Hall to J. G. Keppler, U-10117, dated January 12, 1984). Illinois Power's investigation of the above matter is complete and has determined that the issue does not represent a reaortable deficiency under 10CFR50.55(c). This letter is submitted as a final report, regarding this potentially reportable deficiency.

Statement of Potentially Reportable Deficiency (Withdrawn)

A review by Illinois Power Nuclear Station Engineering Department (NSED) of calculations performed by Sargent & Lundy (S&L) for small bore / instrumentation piping supports and elec-trical conduit supports identified errors in the calculations.

Resolution of the errors has resulted in physical changes to some piping supports to bring the affected piping subsystems into compliance with the ASME Code. No physical changes to conduit supports were necessary.

8406290300 840615 PDR ADOCK 05000461 8 PDR }

c JUN 251984

i Mr. Jam:s G. Keppler Page 2 Background / Investigation Results Small Bore / Instrumentation Piping Supports During August, 1982, IP NSED reviewed a sample of twelve (12) small bore piping support calculations performed by S&L.

The calculations are performed to determine small bore pipe support loads, spans between supports, and flexibility for thermal growth. In the course of the review, NSED discovered errors in the calculations. As a result of these findings, S&L performed a review of an additional thirty (30) calculations.

This review found similar errors, of which several were in the non-conservative direction. Accordingly, an examination of the issue was started.

A hold was placed by S&L on the release of small bore piping support' design documents until corrective action was implemented.

S&L performed a review of the 324 safety-related small bore /

instrumentation pipe support calculations performed to date and identified 159 calculations which contained non-conservative discrepancies to the requiremente of the S&L small piping procedure. To evaluate error significance, these piping designs were further evaluated by S&L using computer analysis or detailed hand calculations, and the results showed that 134 calculations were in compliance with the ASME Code. However, these calculations are being revised to conform with the rules of the . .

small piping procedure in order to ensure that standard design parameters are used throughout the plant. As a result, there will be some hardware changes. The remaining twenty-five (25) calculations were found to be out of compliance with both the small piping procedure and the ASME Code. Calculation revisions are being made, and have resulted in hardware changes to bring the affected subsystems into compliance with the procedure and the ASME Code.

USED completed a review of S&L's calculations that support and validate the S&L small bore piping procedure. This review identified several areas of the procedure that require improve-ment or clarification. In addition, a problem was identified with S&L's span and load tables for piping runs between the containment and the auxiliary building. The calculatiors associated with these problems have been revised, and resulted in one (1) support change. The small bore piping procedure was also revised for clarification and to correct the span and load tables. The revised procedure was reviewed by NSED and found acceptabic.

NSED also has performed a review of selected small bore /

instrumentation piping support calculations performed under the original program that S&L assessed as technically adequate.

Results from this review identified minor problems with the legibility of the calculations. As a result, all 324 calculations are being revised to improve the quality of the records.

Mr. Jcm:s G. Keppler Page 3 A special surveillance was performed by IPQA and NSED which verified that the corrective actions taken by S&L were adequate to prevent recurrence of the types of errors detected in the calculations. As a result, IP authorized S&L to lift the hold on release of design documents for small bore / instrumentation piping supports.

Conduit Supports As a result of calculation errors identified with small bore piping supports, NSED performed a review of a sample of S&L's conduit support calculations. This review included a review of one-hundred-twenty-five (125) electrical conduit support calcula-tions, comprised of twenty-five (25) selected from each of five (5) seismic category I buildings. The results of this review are tabulated as follows:

I. Calculation conservative, support suitable................... 68 II. Calculation discrepancy, support considered suitabic......... 41 III. Calculation discrepancy, support not considered suitable...... 3 IV. Calculation discrepancy, support suitability indeterminate... 13 Total calculations reviewed................................. 125 An evaluation of the discrepancies identified in categories II, III, and IV was completed by S&L and showed that, although discrepancies exist, the supports are adequate as designed.

However, a hold was imposed by S&L on December 13, 1982 on conduit support calculation activities until corrective action was taken and verified to be acceptable by S&L QA, IPQA, and NSED.

S&L QA performed an audit of conduit support calculation activities and identified errors of the same type as those identified by IP NSED in thirty-six (36) of forty-three (43) calculations reviewed. The results of both the IP NSED surveil-lance and the S&L audit identified a total of sixteen (16) errors in the calculations that resulted in support loads exceeding the limits of S&L's standard design tables. Further evaluation of these errors by S&L and NSED found that the supports were ade-quate as designed.

An additional concern was raised during the S&L assessment of the identified calculation errors. It was found that certain base assumptions used in conduit support design were not clearly shown on design drawings or in the electrical installation specification, K-2999. As this information was not provided to Baldwin Associates (CPS Contractor), an inspection of the related hardware attributes to verify conformance with the design assumptions was not made. An Engineering Change Notice (ECN 3360) was issued and incorporated into design documents to

Mr. James G. Keppler

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l provide technical requirements to assure that conduit support installation agrees with conduit design calculations. A reinspection of installed conduit is being performed to assure that the as-built hardware is in agreement with the new design requirements.

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IP QA and NSED surveillances have been performed to verify adequacy of corrective action taken by S&L. These surveillances showed that the corrective action taken by S&L was adequate to prevent recurrence or.the types of errors detected in the calcu-lations. As a result, Illinois -Power QA authorized S&L to release the hold on conduit support calculations.

A review of the t'echnical adequacy of past S&L work in the

l. area of conduit support' design was performed. S&L prepared a plan for reviewing conduit support calculations performed prior to December 13, 1982. This plan was reviewed and approved by Illinois Power QA and NSED. S&L,has implemented the plan and a

-iscued- This report showed l

report documenting that although the review was.l'n conduit support calculations some discrepancies' l existed, the sup) orts are adecuare as designed. NSED evaluated tbn results of ttis review anc, concurred with this, assessment.

Generic detions.

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As a' result of errors found in small bore / instrumentation and conduit support calculations, Sargent & Lundy developed and completed a arogram of technical reviews and quality casurance audits in ot'icr areas of the Clinton design that used procedures j similar to the conduit suppoit Jind small, bore pipe support procedures to asoure adequacy of the calculations. T tese areas include:

a. HVAC suppori:s ,. '

b. Cabih. tray supports '

c. Large bore' pipe support auxiliary steel

d. Reitiforcement of branch connections in piping and Walded attachments to piping ,

j c. Pipe rupture restraints Expansion anchors '-

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The results of tho S&L To.chnlini Evaluation procern identified discrepanbies in the calculations supporting Clinton

, Power Station design in several of the abovo.arpas. Theno l discrepancies were evaluated by S61; and appropriate corrective l action is in progress to currect both the naceific errors and i generic problems. Several minor hardwaro changes were required as a result of the evaluation process.,

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. Mr. Jcmes G. Kcppler Pago 5 Corrective Action Corrective action measures have been established and are being taken by Illinois Power and Sargent & Lundy, as follows:

Small Borc/ Instrumentation Piping Supports

1. S&L procedures for small borc/ instrumentation support design were corrected, expanded, and clarified. These enhancements include instituting a checklist to bc  ;

used by the independent reviewer of calculations to ,

assure an adequate reviews locating analysts on site to review and concur with procedural interpretations:

and locating copics of piping system stress reports at the site for first-hand reference.

2. S&L personnel responsible for preparing and reviewing small borc/ instrumentation piping support calculations were given training in the requirements of the revised procedures.

3. Calculations which contain non-conservative errors or icgibility problems are being reconciled or revised.

This action was authorized by Illinois Power to begin on December 20, 1982, and is essentially complete.

Affected design documents and hardware are being '

revised and corrected as necessary to assure that affected piping subsystems ment the recuirements of the small piping procedure and the ASHE Coco.

4. Technical reviews by IP NSED are being performed on an on-going, sampling basis to monitor technical adequacy 1 of small bore piping support calculations performed by ,

S&L. '

l Conduit Supports

5. S&L has issued a Project Instruction, PI-CP-045,

" Electrical Conduit And Conduit Support Design" that i describes how conduit support design rules are to bo l applied.

6. S&L has issued Electrical Administrative Procedure 35

! that formalizes the training program required for l conduit and conduit support designers. This training

, was given to conduit and conduit support design '

l personnel.

! 7. IP NSED hac developed and impicmented a plan to perform on-going technical reviews of 10%, or a minimum of ono l (1) per building, of conduit support calculations j parformed by S&L during onch month, to monitor techni-cal adecuacy of the eniculations. This plan will be

' adj us tet no experience is gained with the quality of the new calculations.

. x I "'  %+ 'llr. James G.-Keppler Page 6- 1s s

GdnericActions

8. As a result of discrepancies noted during S&L's Technical Evaluation program, corrective actions to correct these specific discrepancies and their root' causes have been identified, and are being implem<ated.

9. Ill'inois-Power'NSED andsQA are_ expanding their techni-cal review / audit activities oi,S&L's design. To date, design reviews of cabletrayr,s,upport, large. bore piping, soil settlement',s and1' structural steel have been

. conducted, with others 1-scheduled for the future.

Safety Impl'ications/ Significance ,

SignificantresourcesahdSimewereexpended-inresolving this potentially reportable deficiency. However, these resources would have been engaged insthis activity in any event, and this issue provided specific direction to IPC design review efforts.

Hardware changes were mado to bring small bore /

-instrumentation piping subsystems affected by calculation errors into compliance.with the ASME Code. However, a review of calculation discrepancies.in the areas of~ electrical conduit

-supports, small bore / instrumentation piping supports, and in

-areas evaluated under the Technical Evaluation Program, has been performed by S&L and'has shown *that the errors,-if gone .

~

.- uncorrected, would not have impacted plant safety. Illinois Power NSED has evaluated this S&L review and has concurred with the finding. Therefore, this condition-is considered to be not reportable under the provisions of 10CFR50 55(e).

We trust that this final-letter providesusufficient.

'information for you to perform your assessment of this deficiency.

and of our overall approach to resolve the problem.

Sincerely yours.,

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. D. P. Hall Vice'?

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Director, Office of I&E, USNRC, Washington, D.C. 20555 Illinois Department of Nuclear Safety INPO Records Center s [_ .[ ,

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