ML20079H097

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

ML20079H097
Person / Time
Site:	Clinton
Issue date:	01/12/1984
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-10117, NUDOCS 8401230322
Download: ML20079H097 (7)

Text

.

me ILLIN0/8 POWER 00MPANY f_ y CLINTON POWIR STATION. P.O. BOX 678. CLINTON. ILLINOls 61727 January 12, 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 Deficiency 55-82-09 10CFR50.55(e)

Small Bore / Instrumentation Piping, and Conduit Support 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 bore / instrumentation piping support design calculations performed by Sargent & Lundy (CPS Architect-Engineer). This initial notification was followed by five interim reports (Ref:

IP letter, D. P. Hall to J. G. Keppler, U-0555, 1605-L, dated October 1, 1982, IP letter, D. P. Hall to J. G. Keppler, U-10014, 1605-L, dated December 21, 1982, IP letter, D. P. Hall to J. G.

Keppler, U-10040, 1605-L, dated March 28, 1983, IP letter, D. P.

Hall to J. G. Keppler, U-10071, 1605-L, dated July 6, 1983, and IP letter, D. P. Hall to J. G. Keppler, U-10099, 1605-L, dated September 30, 1983). Illinois Power's investigation of tae above matter continues. This letter is submitted as an interim report, in accordance with 10CFR50.55(e)(3), to keep you informed of our progress.

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

Resolution of the errors have resulted in physical changes to some piping supports. No physical changes to conduit supports were necessary. The evaluation continues, to determine reportability of the issue as a deficiency in final design under 10CFR50.55(c).

e401230322 84o112 1 0 PDR ADOCK 05000461 '

S PDR JAN 16 B84

7 L

Mr. Jcmes G. K:ppler Page 2 January 12, 1984 Background / Investigation Results Small Bore / Instrumentation Piping Supports l l

During August, 1982, IP NSED reviewed a sample of twelve l (12) small bore piping support calculations performed by S&L.

The calculations are performed to determine small bore pipe I 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 imnlemented.

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

instrumentation pipe calculations performed to date and iden-tified 159 calculations which contain non-conservative discrep- 1 I

ancies to the requirements 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 calcu-

.lations, 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 i were found to be out of compliance with both the small piping l procedure and the ASME Code. Calculation revisions are being I made, and have resulted in hardware changes to bring the affected l subsystems into compliance with the procedure and the ASME Code, l An S&L analysis of these 25 calculations showed that none of the i discrepancies would have adversely affected the safety of I operation of CPS. l 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.

NSED 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 calculations  !

associated with these problems have been revised, and resulted in I I

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 (

acceptable.

i Mr. Jcm:s G. Keppler Page 3 January 12, 1984 NSED also has. performed a review of selected small bore /

instrumentation piping 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.

NSED is continuing its review of the technical adequacy of S&L's work in the area of small bore / instrumentation piping design. NSED has begun a review of S&L's justification and revised calculations with regard to impact on plant safety for those twenty-five (25) subsystems which did not meet ASME Code allowables. An analysis as to the safety significance of these subsystems will also be performed.

Conduit Supports As a result of calculation errors identified with small bore piping eupports, NSED performed a review of a sample of E&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 followsr I. Calculation conservative, support suitable................... 68 II. Calculation discrepancy, support considered suitable. . . . . . . . . 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 shoaed that, although discrepancies exist, the supports are adequate as designed.

However, a hold was impoced by S&L on December 13, 1982 on conduit support celculation 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.

Mr. James G. K ppler Page 4 January 12, 1984 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 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.

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 of 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.

IP is continuing its review of the technical adequacy of past S&L work in the area of conduit support design. S&L pre-pared a plan for reviewing conduit support calculations performed orior to December 13, 1982. This plan was reviewed and approved by Illinois Power QA and HSED. S&L has implemented the plan and a report documenting the review was issued. This report showed that although some discrepancies in calculation existed, the supports are adequate as designed. NSED is evaluating the results of this review for adequacy.

Generic Actions 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 assurance audits in other arens of the Clinton design that used procedures similar to the conduit support and small bore pipe support procedures to assure adequacy of the calculations. These areas include:

a. HVAC supports

b. Cable tray supports

c. Large bore pipe support auxiliary steel I

d. Reinforcement of branca connections in piping and welded attachments to piping

c. Pipe whip restraints

f. Expansion anchors

a j ,1 T1  : Mr. Jamas G. Koppler .Page 5 January 12, 1984

.The results of the S&L Technical Evaluation identified discrepancies in the calculations supporting Clinton Power Station ~ design in several of~the above areas. These discrep-ancies were evaluated by S&L for1 root causes, and appropriate corrective action to correct both the specific errors and generic problems-have been identified. Most of the corrective actions have.been completed and the remainder are in progress. However, none of the discrepancies identified by the Technical. Evaluation i have resulted in a physical change to hardware. Illinois Power is presently evaluating the report for adequacy.

Corrective Action (Interim)

Corrective action measurea have been established and are

' being taken by Illinois Power and Sargent & Lundy, as follows:

Small Bore / Instrumentation Piping Supports 1.. S&L procedures for small bore / instrumentation support design were corrected, expanded, and clarified. These enhancements include: instituting a checklist to be 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 copies of piping system stress reports at the site for first-hand-reference.

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

3. Calculations wnich contain non-conservative errors or legibility problems will be reconciled or revised.

This action was authorized by Illinois Power to begin on December 20, 1982, and-is estimated to be completed by January 31, 1984. Affected-design documents and

-hardwarc will be revised and corrected as necessary.

4. NSED is tracking the resolution and status of problems

resulting from the calculation discrepancies. This action will continue until all calculations requiring revision have been completed and drawings are revised.

Hardware changes will also be tracked by Illinois Power.

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

-S&L.

N. - '. I- .

Mr. James G. Keppler Page 6 January 12, 1984 Conduit Supports

6. S&L has issued a Proj ect Instruction, PI-CP-045,

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

7. S&L has issued Electrical Administrative Procedure 35 that formalizes the training program required for conduit and conduit support designers. This training was given to conduit and conduit support design personnel.

8. IP NSED has developed and implemented a plan to perform on-going technical reviews of 10%, or a minimum of one (1) per building, of conduit support calculations performed by S&L during each month, to monitor techni-cal adequacy of the calculations. This plan will be adjusted as experience is gained with the quality of the new calculations.

Generic Actions j 9. As a result of discrepancies noted during S&L's Techni-i cal Evaluation program, corrective action to correct I these specific discrepancies and their root causes have been identified, and-are either complete or are being implemented by S&L. Illinois Power NSED and QA will perform an evaluation of S&L's corrective action on these issues to verify adequacy.

10. Illinois Power NSED and QA are expanding their techni-cal review / audit activities or S&L's design. To date, design reviews of cable tray support, large bore piping, soil settlement, and structural steel have been conducted, with others scheduled for the future.

Safety Implications / Significance A review of calculation discrepancies in the area of elec-trical conduit supports and small bore / instrumentation piping supports has been performed by S&L and has shown the errors do not impact plant safety. IP NSED is presently evaluating the results of the S&L analysis for technical adequacy. IP will also perform a review of the results of S&L's Technical Evaluation program for adequacy and significance, and the results will be

> analyzed for trends which will aid in evaluating the need for additional generic corrective action. An evaluation of this potential deficiency will be completed in approximately ninety (90) days.

> a lir. Jcm s G. Kcpplcr Page 7 January 12, 1984 I

We trust that this interim 1ctter provides sufficient information to perform a general assessment of this deficiency and adequately describes our overall approach to resolve the problem.

Sincerely yours,

. P. Hall Vice President REC / lag cc: NRC Resident Office Director, Office of I&E, USURC, Washington, D.C. 20555 Illinois Department of Nuclear Safety INPO Records Center

.- - _ _ _ _ _ _ _ _ _