ML20083K409

Final Deficiency Rept 82-12 Re Binding of Sway Strut/Snubber Piping Component Supports.Initially Reported on 821021. Installed Supports Not Having Required Clearances Will Be Reworked to Provide Necessary Freedom of Action

ML20083K409
Person / Time
Site:	Clinton
Issue date:	04/04/1984
From:	Hall D ILLINOIS POWER CO.
To:	Kepper J, James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
82-12, U-10136, NUDOCS 8404160163
Download: ML20083K409 (4)

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_ 1605-L ILLINDIS POWER 00MPANY U-10136 CLINTON POwl1 S'ATION, P.O. BOX 678. CLIN 1 JN, ILLINOIS 61727 April 4, 1984 Decket No. 50-461 Mr. James G. Keppler Regional Administrator Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Subject:

10CFR50. 55 (e) Deficiency 82-12 Binding of Sway Strut / Snubber Piping Component Supports

Dear Mr. Keppler:

On October 21, 1982, Illinois Power notified Mr. H. Vescott, NRC Region.III, (Ref: IP memorandum Y-13998, 1605-L, dated October 21, 1982) of a putentially reportable deficiency per

'10CFR50.55(e) concerning the fabrication of sway strut type pipe supports. The location _of welds on the eyelet of the sway strut interferes with the retaining bracket (clevis) such that the required motion _of the sway strut may not be achieved. This initial notification was followed by five (5); interim reports

- ( Re f : - IP letter U-10011, D. P. Hall to J. G. Keppler dated November 20,~1982,-1605-Li IP letter U-10032, D. P. Hall to J. G.

Keppler dated February 18,11983, 1605-L IP letter U-10058, D. P.

Hall _to J. G. Yeppler dated May 31, 1983: IP letter U-10089, D.

P.-Hall:to J. G. Keppler dated September 8, 1983; and IP letter U-10112, D. P. Hall to J. G. Keppler dated December 22, 1983).  :

Our investigation into this mattershas determined that this issue represents a reportable deficiency,under the provisions of 10CFR50.55(e). This letter represents a final report in accordance~with 10CFR50.55(e)(3).

Statement of Reportable' Deficiency.

The welded male rod extension piece used in sway strut and snubber , piping -supports supplied by Basic Engineers .(BE) binds in the'pipt clamp and rear bracket, limiting the designed range of motion.J'The 31nding could cause. extra loads on the weld ~ attach--

ing the. rear bracket (clevis) to the structure.. This additional-load could result in overstress of the weld, and potentially, failure of the weld.

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J. C. Koppler April 4, 1984 NRC Background /Investigatiou Results During inspection activities of piping support installation by Baldwin Associates (IP Contractor), a sway strut type pipe support was found where metal to metal contact existed between the male rod extension piece and the pipe clamp This condition does not conform wiuh Baldwin Associates Procedure BAP 3.2.5 (Piping Compcnent Supports), which requires the piece to pivot ir all directions without binding. A Deviation Report (DR-3382) was initiated to document this occurrence. Further investigation determined that these male rod extension pieces had also been used on sway strut type supports to connect to the rear bracket i

(clevis), and therefore binding could also occur at this location. This concern was confirmed by a randon inspection of installed sway strut supports which identified several interferences. Additionally, some mechanical snubbers utilize similar male rod extension pieces and could be subject to binding.

The problem was further investigated by the piping support supplier, Basic Engineers. Their investigation found that the interferences were due tc accumulative fabrication tolerances provided on BE's data sheets for these types of supports.

Investigation by Baldwin Associates determined that, in soma casec, overwelding c.f the eyelet to the threadr.3 rod of the male rod extension piece, as well as overwelding of the rear bracket also contributed to the interferences.

In order to determine the scope of this problem on installed hardware, an inspection program was implemented at Clinton Power Station (CPS). This inspection progran utilized personnel employed by Basic Engineers on site to measure the clearances available er.d the critical dimensions for installed sway struta and snubbers. Using the actual dimensions for each installation, the availnble freedom of movement was calculated, acceptability of each support determined, and corrective action for each unacceptable support established.

The inspection and resultant analysis has' determined that approximately 1,100 installed pipe supports will require rework.

The rework generally will consist of an adjuctment to existing-support' hardware. In sore cases, however, replacement of existing support hardware will be necessary to obtain the required freedcm of movement. A complete listing of affected supports hns been developed and work documents are being' prepared to control the necessary rework and reinspection.

Investigation has also determined that supports could exist which appear bound in the cold condition, yet adequate-:learance mayLbe'available due to movement of the hanger resulting from

. thermal growth of the pipe. .Sargent E Luady (CPS Architect-

)- Engineer) design standnrda allow the pipe support joint to move withir. 2* without design compensation.' However, in caces where c

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J. G. Keppler April 4, 1984 NRC large thermal movements or short struts are involved, design compensations, such as offsetting the attachments to the pipe and ,

structure, may have been made to accommodate this movement such 1 that the support in its cold setting may appear bound. A list of I affected supports with offset attachments has been compiled by Basic Engineers using Sargent & Lundy design drawings; general inspection criteria for these supports have been developed. A limited number of supports (16) require greater clearance than provided in the general inspection criteria. These supports will be inspected to specific design requirements.

Corrective Action

1. Installed supports that do not have the required clearances will be reworked to provide the necessary freedom of movement. This rework will be initiated as follows:

a. For non-safety related supports requiring rework, Construction Work Requests (CWRs) or rework orders will be issued tu correct the hardware.

b. For safety related supports requiring rework, travelers er traveler supplements are being issued / reissued to the field to implement the required rework. The corrected hardware will also be reinspected to assure adequate clearance.

. To assure that future installations have adequate freedom of

-uovement, the following actions have been taken:

a. Baldwin Associctes stopped issuing welded male rod extension pieces (BE part Nou. 415-1 and 411-2) tu the field and fabrication shops until after an inspection of hanger parts had-been performed in each building's lay down area. Defective parts were tagged and segregated to prevent inadvertent use or installation,

b. Baldwin Associates Quality Assurance intensified its surveillance of' Basic Enginects' fabrication activities at BE's shops.

c. Quality Control Instruction QCl-300, Inspection of Piping Component Supports, was revised and issued to

' include' detailed instructions for making binding inspections for non-offset and offset supports.

Training was provided to Quality Control inspectors on this matter,

d. Basic Engineers has supplied Baldwin Associates Quality Control with feeler gauges to implement the binding enecks detailed in QCI-300. The gauges are calibrated in accordance with applicable procedures.

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J. G. K ppler April 4, 1984 NRC

e. Sargent & Lundy drawing M09-100]N was r< vised to clarify installation tolerances with regard to pipe supports.

Safety Implien.tions/ Significance It can be postulated that, had the deficiency gone uncorrected, the binding in the pipe support could cause extra stress in the weld attaching the support to the structure, potentially resulting in failure of the weld and support. A pipe support failure could result in piping stresses that exceed ASME Code allowables. On this basis, and due to the extensive rework required to assure that pipe supports acequately perform their intended function, this issue is considered to be reportable under the provisions of 10CFR50.55(c).

It is expected that an extended period of time will be required to fully complete all hardware-related ccrrective action identified in this report. However, tracking systems have been established to assure that rework is fully implemented and that documentary evidence of its completion is gcnerated and maintained. We trust that this final report provides sufficient information to perform a general assessment of this reportable deficiency and adequately describes our overall approcch to resolve the problem.

Sincerely yours, i

. . Hall Vice President RDW/ lag cc: Director, Office of IGE, U.S. NRC, Washington, DC 20555 Illinois Department of Nuclear Safety NRC Resident Office INPC Records Center 1

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