ML20076K556

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

ML20076K556
Person / Time
Site:	Clinton
Issue date:	07/06/1983
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, 82-09, 82-9, U-10071, NUDOCS 8307180009
Download: ML20076K556 (7)

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rLLINDIR POWER 00MPANY 16 05-L j)CF U-10071 CLINTON POWER STATION P.O. BOX 678. CLINTON. ILLINOIS 61727 July 6, 1983 Docket Number 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 82-09

'10 CFR50. 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 three interim reports (Ref:

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

G. Keppler, U-10040, 1605-L, dated March 28, 1983). Illinois Power's investigation of the above matter' continues, and 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 Deficienc",

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 could result :ba ' changes' to the supports, )

or require the' installation of additional supports. An evalua- {

tion is being performed to determine the magnitude and -

significance of these errors, the potential for errors in other areas.of design performed by'similar methods, the impact on

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~,. 1.fMr. J. G. Keppler - JulyL6, 1983 NRC installed ~ hardware, the potential for adverse impact on the

- safetyc of operations of Clinton Power Station (CPS), and reportability- as a deficiency in final design under 10CFR50.55(e).

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'7erformed to determine small bore pipe support loads, spans 3etween supports, and flexibility for thermal-growth. In the cou'rse 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 has performed a review of the 324 safety-related small bore / instrumentation pipe calculations performed to date and identified ~134 calculations which contain non-conservative discrepancies 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 calculations, and the results showed 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 plan t , and will result in some hardware changes. Further, .

twenty-iive (25) calculations of small bore / instrumentation piping.were found to be out-of compliance with both the small 11 ping procedure and the ASME Code. Calculation revisions are 2eing made, and will1 result in hardware changes to bring the affected subsystems into compliance with the procedure and the '

ASME. Code. An S&L analysis of these 25-calculations has been

. performed, which showed that none of the discrepancies would adversely affect the safety of operation of. CPS.

A1special surveillance was performed by Illinois Power QA

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L and NSED which' verified that'the corrective actions ~taken-by S&L i were adequate.to prevent recurrence of'the types of errors i detected in'the calculations. 1As a result, IP authorized S&L to L Llift?the hold on release of design documents.for small L

Lbore/ instrumentation piping supports. l L NSED is; continuing its review of1the technical adequacy of L S&L's' work in ~ the : area of small bore / instrumentation piping

design as follows:'

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- Mr. J.T G, Keppler - July 6, 1983

~NRC

1. 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 improvement or clarification.

In addition,~ a potential problem was identified with S&L's span and load. tables for piping runs between the containment and the auxiliary building. The extent and impact, if any, of these problems is still under evaluation.

2.- NSED has implemented a program of on-going reviews of selected new small bore piping calculations performed i by S&L during each month. Results thus far have indicated that the new calculations are adequate.

3. NSED is tracking the resolution and status of problems

resultiag from the calculation discrepancies. This action will continue until all calculations requiring l

revision have been completed and drawings are revised.

Hardware changes will also be tracked by Illinois Power.

i 4. NSED will perform a review of S&L's justification and supporting calculations with~ regard to impact on plant safety.for those subsystems which did not meet ASME l Code allowables. In addition, an analysis as to the safety significance of these subsystems will be per-formed'by NSED.

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5. NSED 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 identitied minor problems 'with the legibility of the calculations. As a result, all 324 calculations will be revised.

Conduit Supports 1 .

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

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II. Calculation discrepancy, support-considered suitable......... 41 III~. Calculation discrepancy, support not considered suitable...... 3 IV. Calculation discrepancy, supporttsuitability indeterminate... 13 L

. ' Total calculations reviewed................................. 125 l L,~

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Mr. J. G. K:pplar July 6, 1983 NRC 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, Illinois Power QA, and NSED.

IPQA and NSED surveillances of the issue found that S&L's conduit support procedures did not always provide standard methods for preparing and reviewing the calculations, therefore, reliance was placed on individual interpretation and engineering judgement to perform the tasks. Additionally, calculations for conduit supports were not always prepared and reviewed properly, due to insufficient attention to detail by the preparers and reviewers. S&L QA also performed an audit of conduit support calculation activities. This audit 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 surveillance and the S&L audit identified a total of sixteen (16) errors in the calculations that resulted in support loads exceeding the limits of the standard design tables. Further evaluation of these errors by S&L and NSED found that the supports were adequate.

An additional concern was raised during the S&L assesement 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) has been issued to revise K-2999, to incorporate the necessary design information required to assure that conduit support installation agrees with conduit design calculations. A reinspection of installed conduit is being performed as part of an Illinois Power Company Recovery Plan for Electrical Conduit, to assure that the as-built hardware is in agreement with the new design information.

An IP QA and NSED surveillance has been performed to verify adequacy of corrective action taken by S&L. This surveillance showed that the corrective action taken by S&L was adequate in all areas of conduit support calculations, with the exception of four (4) types of supports (JS type box supports, TCC, TH, and THB trapeze type conduit supports). These four types of supports were placed on hold by S&L pending the development of simplified design tables. Illinois Power QA authorized S&L to release the hold on conduit support calculations in all but the four problem areas identified above.

NSED is continuing its review of the technical adequacy of S&L work in the area of conduit support design as follows:

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l a RHr. J. ' G.- Keppler ' July 6, 1983 NRC-I

1. Illinois Power QA and NSED evaluated and accepted S&L's plans for reviewing-conduit support calculations performed prior to December 13, 1982. S&L has imple-mented the plan and a report documenting the review is being prepared. NSED will evaluate the results of this review for adequacy.

' 2. . NSED has evaluated calculations prepared by S&L as the

' basis for design tables contained in the conduit support design procedures. This eva uation found the calculations to be acceptable.

Corrective Action (Interim)

Corrective action measures 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 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. As a result of NSED's technical reviews, these procedures are being further revised, and will be reviewed for adequacy and impact on completed work.

2. Personnel responsible for preparing and reviewing small bore / instrumentation. piping support calculations were given training in the requirements of the revised-procedures. Further training will be given upon completion of procedural revisions identified in 1.

above.

3. Calculations which contain non-conservative errors 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 July'29, 1983.- Affected designidocuments and-hardware will be revised and' corrected'as necessary. Two-hundred-sixty-two'(262) of three-hundred-twenty-four (324)' calculations have been revised to date, u4 . Technical reviews by IP NSED'are being performed on an

~on-going;1 sampling' basis to monitor technical adequacy l

, of small bore -piping support calculations performed by S&L.

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• - Mr. Ji G. Keppler -6.- July 6, 1983 NRC Conduit Supports

5. A hold.on electrical conduit support design activities remains in effect for JS, TCC, TH, and THB type support calculations, until appropriate corrective actions are taken and found acceptable by S&L QA, IP QA, and NSED.

Corrective actions in progress include a revision to the conduit support design manual.

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 Department Administrative (

l 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 technical adequacy-of the calculations. This plan will be adjusted as experience is gained with the quality of the new calculations.

Generic Ac'tions

' 9. Sargent & Lundy has initiated a program of technical reviews and quality assurance audits in other areas of the Clinton-design that used procedures similar to the

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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

'd. . Potential interactions

e. Instrumentation setpoints

f. Reinfo~r cement of branch connections in piping and welded attachments to piping- ,

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g. Pipe ~ whip. restraints

-h. . Expansion anchors 1

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10. Illinois JPower NSED and',QA are expanding their techni-call review'/ audit . activities' of S&L's design. To date, ~~

reviews.of gable; tray support design and large b' ore piping ' des (gn havd byen conducted with others - scheduled -

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'A 'revie~wd(( calculation discrepancigs 'in the areaTof elic}- -

1 trical conduit'sdpports and sial-1J bgre/,instrupentation pfping - "

supports has been performed by1S6#~and. has Nhown the errors do not impact' plant. safety. IP NSEDMill' eva16 ate the results of the S&L analysis for tebtnic$ndependently,A s c1 adeque47 s

revi'ew'of pastAcalculations in the area. of 'el'ectrical condy,Q supports and small bore / instrumentation piping supportpis alsb on-going to' ,

deteimine the adequacy'of the desisa; 'hy iden'tifitd "

discrepancies will'be evaluated to-determine the impact on plant safety. e Thd results.will r ot cause also and be\ analyzed svaluatingfor th(trenda nped'for which Will N 5 -y aid in identifyin);'c@rredtive additional, generic o action. An evaluati k of this k J potential. ' deficiency

will be completed in approxiniat.a.ly ninety 1

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information to pirform a general assessment of this defic 19t Oy and adequatelysdescribes problem. W .

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