ML20069H185

Interim Deficiency Rept 82-09 Re Small Bore/Instrumentation Piping Support Design Calculations.Initially Reported on 820902.Review of All Calculations to Determine Extent of Errors Underway.Next Rept Due in 90 Days

ML20069H185
Person / Time
Site:	Clinton
Issue date:	10/01/1982
From:	Hall D ILLINOIS POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
10CFR-050.55E, 10CFR-50.55E, 1605-L, U-0555, U-555, NUDOCS 8210190416
Download: ML20069H185 (3)

Text

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/LLIN0/8 POWEP 00MPANY j U-0555 CLINTON POWER STATION P.O. BOX 678, CLINTON, ILLINOIS 61727 October 1, 1982

. Mr. James G. Keppler Regional Administrator, Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Dear Mr. Keppler:

Potential Deficiency 82-09 10 CFR 50.55(e)

Small Bore / Instrumentation Piping Support Design Calculations 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 concerning discrepancies identified by Illinois Power in a sample of emall bore /

instrumentation piping support design calculations performed by Sargent & Lundy (CPS Architect-Engineer). Our investigation into this matter continues, and this letter represents an interim report per 10 CFR 50.55(e).

STATEMENT OF POTENTIALLY REPORTABLE DEFICIENCY An independent review by Illinois Power Nuclear Station Engineering Department (NSED) personnel of Sargent & Lundy (S&L) calculations for small bore / instrumentation piping supports, identified errors in the calculations. Resolution of the errors could result in changes to pipe supports released for construction, or require the installation of additional supports. An evaluation is being performed to determine the magnitude and significance of these errors, their impact on installed hardware, and the potential for adverse impact on the safety of operations of Clinton Power Station.

INVESTIGATION RESULTS/ BACKGROUND During August, 1982, Illinois Power NSED personnel reviewed a sample of twelve (12) small bore piping support calculations performed by S&L's on-site small bore piping design group. The calculations are performed to determine small bore pipe hanger loads, spans between hangers, and flexibility for thermal growth. In the course of'the review, NSED personnel discovered 8210190416 B21001 N

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errors' in more. than half of the calculations. The type of errors identified included mathematical errors, errors in the transposition

- of measurements from . design drawings for use in calculations, and

., errors in the . selection of appropriate design input and rules provided in.small bore pipe hanger design procedures. As a result of these findings S&L performed a review of an additional thirty (30) calculations. This? review found more - errors,. several of which were in the non-conservative direction. Although S&L's design procedures contain a degree of conservatism which . can accommodate the type of errors identified, the-potential for significant errors in this case could not be discounted. A review of all completed small bore hanger calculations is presently being performed by S&L to determine the magnitude of this problem and the. significance of the errors.

, CORRECTIVE ACTION (INTERIM)

Although investigation of this potentially reportable deficiency is still on-going, several actions have been, or are being taken to prevent further errors in small bore piping support calculations:

1. Small bore support calculation procedures were reviewed by l Sargent & Lundy for simplifications and other modifications that could be made to prevent recurrences of the errors g found in the calculations. This review resulted in several changes to the procedures to clarify the design process.

9 Sargent & Lundy personnel involved in the preparation and review of small bore piping support calculations will be i retrained in the various procedural requirements which control the work.

3. A checklist has been developed to specifically note the.

items that calculation reviewers are responsible .for checking. The ' applicable. Project Instruction for the design of small bore pipe supports (PI-CP-036) will be j revised to incorporate the use of this' checklist.

4.. -S&L Quality Assurance Division has performed an internal.QA audit to evaluate _ the adequacy of procedures, procedure implementation, and personnel training related to .small bore' piping support design calculations.

5.. S&L- Proj ect' Management Division is performing a re review -

of small bore piping support calculations to determine the ,

extent . and nature of ' errors in the calculations and to

,. assess the adequacy;of existing design documents.

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-6. Those supports which . have been identified ' as having .a

.pctential for hardware l changes have been put on " hold"'via

an Engineering Change ~ Notice.;

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-J.G.-Kepplcr October 1, 1982 NRC Page 3 of 3 7.- S&L.has imposed a hold on the release of design drawings for new small bore piping supports. This hold will remain in effect ~ until Illinois Power Quality Assurance and NSED have verified that adequate corrective action has been taken to resolve the identified problems and to prevent recurrence, and that all nonconformances ident!fied by the

~S&L QA audit have been resolved.

SAFETY IMPLIpA2 IONS / SIGNIFICANCE A re-review of all small bore piping support calculations to determine the extent-and nature of the errors is presently on-going.

'When the results of this re-review are complete, the identified errors will'be closely analyzed to determine impact on plant hardware and significance on plant _ safety. The results will also be analyzed for trends which will aid in identifying root causes and evaluating the need for additional corrective action. It is anticipated that approximately - ninety (90) days will be necessary to complete an investigation, to determine reportability, and to le our final.

report on the potential deficiency.

We trust that this interim letter provides you sufficient

. background information to perform a general assessment of this potential reportable deficiency and overall approach to resolution of

.the problem.

i V truly yours, D. . Hall Vice President cc: H.H. Livermore, NRC Resident Inspector Director, Office of I&E, Washington, D.C. 20013 Illinois Departmcat of-Nuclear Safety Director-Quality Assurance' f

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