U-600465, Part 21 Rept (21-85-06) Re Potential Failure of Sway Strut & Snubber Pipe Clamps Supplied by Basic Engineers.Caused by Loose Clamp Bolts.Revised Clamp Load Capacity Data Sheets & Installation Instructions Encl

Part 21 Rept (21-85-06) Re Potential Failure of Sway Strut & Snubber Pipe Clamps Supplied by Basic Engineers.Caused by Loose Clamp Bolts.Revised Clamp Load Capacity Data Sheets & Installation Instructions Encl

ML20155A235
Person / Time
Site:	Clinton
Issue date:	03/31/1986
From:	Hall D ILLINOIS POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
REF-PT21-86, REF-PT21-86-094-000, REF-PT21-86-213-000 (21-85-06), (21-85-6), 21-85-6, 4-600465, PT21-86-094-000, PT21-86-213, PT21-86-213-000, PT21-86-94, U-600465, NUDOCS 8604080337
Download: ML20155A235 (4)

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D .1yt.d 3 U-600465

- L16-86 ( 03 -31 )-L 1A.120 ILLINDIS POWER COMPANY IP CLINTCN PCMR STAf t0N. P.O. B01678. CLINTON. ILLINOIS 61727 March 31, 1986 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:

10CFR Part 21 Defect - Failure of Sway Strut and Snubber Pipe Clamps at Clinton Power Station (21-85-06)

Dear Mr. Keppler:

In Illinois Power Company's (IP) Letter U-600208, dated August 12, 1985, you were notified that IP was conducting an evaluation of a potential 10CFR Part 21 defect in certain sway strut and antibber pipe clamps supplied by Basic Engineers for use at the Clinton Power Station (CPS).

Based on that evaluation, IP has concluded that had this defect gone undetected, it would have resulted in inadequate support of various safety-related piping systems in the faulted condition. This could have affected the integrity of those systems and is judged to be a reportable defect under the provisions of 10CFR21. Therefore, IP is providing the following information in accordance with the requirements of 10CFR Part 21:

(i) D. P. Hall, Vice President of Illinois Power Company, by means of this report, hereby informs the Commission of a 10CFR21 defect.

(ii) The components involved ir. the reportable defect evaluation are sway strut and snubber pipe clamps in sizes 3/4" and 1".

(iii) The clamps were supplied to CPS by Basic Engineers, a division of National Valve and Manufacturing Company.

(iv) Basic Engineers became aware of certcin conditions in their 3/4" and 1" clamps which could cause the clamps to slip circumferential1y around the pipe when a compressive load equal to the faulted rated load was applied to the clamp at an angle of 5' from the clamp centerline. Tightening the clamp bolts tight enough to prevent rotation results in stretched bcits and probable failure. Testing and evaluation programs at Basic Engineers failed to detect the conditions pre-sented here prior to supplying the product to CPS.

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l PDR ADOCK 05000461 1986 i A PDR j 1

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. L16-86 (03 -31 )-L 1A.120 (v) On June 10, 1985, National Valve notified Baldwin Associates (EA) (general contractor for CPS) and BA notified the Manager of Quality Assurance, Illinois Power, on June 13, 1985.

(vi) BA identified a total of 188 pipe hangers which were originally designed with the clamps manufactured by Basic Engineers. Fifty-nine of these were either voided or revised to other design configurations.

Sargent and Lundy (S&L) determined that 129 hangers were installed using 'cha subject clamps. Eleven of these were reworked under FECN No. 11996 and FECN 12040. The balance (118) were reworked under FECN 12559. The number and system location of the defective clamps are given in Attachment "A".

(vii) The corrective action which has been taken is as follows:

(a) Basic Engineers has revised the clamp load capacity data sheets and installation instructions to provide new torque values.

(b) Basic Engineers has changed the material require-ments to use higher strength nuts and bolts with hardened washers to prevent stretching the bolts.

(c) S&L performed a computer sort to identify all pip'e support types S, R & X for pipe sized 3/4" and l at the CPS. BA used this sort to establish a list of all affected safety related small bore hangers.

(d) All affected hangers have been identified and change documents have been issued to identify this condition in the M09-1003N & 1004N drawings.

(e) The affected supports were re-worked per Field Engineerlag Change Notices issued by S&L (FECN 11996, FECN 12040 and FECN 12559). The work was '

completed in February, 1986.

(viii) Not applicable to Clinton Power Station.

Our evaluation of this reportable defect is available for your review at our offices. I trust that this letter provides sufficient information for your review and analysis of the problem and solution.

Sincerely yours,

, /

. . Hall k Vice President RLC/ckc

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' L16-86 (03 -31 )-L 1A.120 I

. cc: USNRC Residenc Office

'? Illinois Department of Nuclear Safety D(rector of Inspection and Enforcement.(3 copies)

INPO Records Center Nat iottal Valve c.nd Manufacturing Company f

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i 10CFR21 (21-85-06) n Page 1 of 1 ATTACRMENT A M-1AB03072X M-1RB12513S M-IRE 20049X M-lIS01074S M-lRB21616S M-1RE42021X M-IIS01075S M-1RB21505S M-JRH73001X M-lIS08024X M-1RB21596S M-1RH73002S M-]MS10201S M-1HB21597S M-IRH82002S M-1MS10301S M-1RB21598S M-1RH82003X M-1MS10401S M-lR.B21599S M-1R121006S M-1MS10501S M-1RB21609S M-1RT19003X M-1MS10602S M-1RB216118 M-1RT280073 M-lMS38072S M-1RB21614S M-1RT46001S M-1MS38073X M-IRB22555S M-lSX03018X M-1MS38093S M-1RB24565S M-ISX04017X t M-1MS38094S M-1RB24567S M,1SX48007X M-1MS38095S M-lRB24568S M-1SX49006X

'M-1MS38096S M-1RB24569S M-1TX16049S M-1MS4600ls M-1RB24575S M-1RB2162SS M-1MG48003S M-lRB31514S M-1RB23542S M-lMS48005S M-1RB31529S M-1RB24580S M-1MS49002R M-1RB31597S M-1RB14553S M-1MS49003S M-lRB33510R M-1RB14554S M-1MG49004R M-1RB33516S M-1RR09006S M-U'34 9 005S M-1RB34507R M-1RR10006S

, .Mv1Ha50001S M-1RB34511R M-1RR29022S M-lMS50bO2R M-1RB34515X M-1RR29026S M-1MS87009S M-1RE16002X M-1LP08028X M-1RA03017X M-lRE16004X M-1HP09001R M-1RA03020X M-1RE16032X M-1RE16001X M-1RB11534S M-lRE16039X M-1RE16013X M-lRB11535S M-1RE20011X M-1RE16014G M-1RBil537S M-1RE20020X M-1RE16030S M-1RB11539S M-lRE20041X M-1RE16037S

-M-1RE16050X M-lRE16059X M-lRE20038X M-TRE420428 M-1RE42043S M-1RR05001R M-1RR07001R M-lRT28096S M-1SC01016R M-1SC01017R M-ISX68015R M-1TD19001X M-1TD19006X M-1TD19011X M-lTD20001X M-lTD20005X M-lTD20010X M-1TD28001X M-1TD28002R M-lTD31001R M-1TD31002R

.M-1TD44001X M-1TD44002X M-1TD44010X M-lTD44013X M-1TD4!001X M-1TD45002X M*1TD45011X M-lTD45014X M-1RE16012S M-RES01921R M-WZS00804X M-WZS00831X (9ES00630X) ESS00630X M-1RA03002R (3ES00634X) ESS00634X

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