ML20028C923

Interim Deficiency Rept Re IE Circular 81-05, Sway Strut/ Snubber End Bushings. Initially Reported on 821202.No Bushing Disengagement Should Occur.Strut Rework Will Be Completed Prior to Sys Turnover.Next Rept Expected 830320

ML20028C923
Person / Time
Site:	Columbia
Issue date:	12/30/1982
From:	Matlock R WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
REF-SSINS-6830 10CFR-050.55E, 10CFR-50.55E, G2-82-1025, GO2-82-1025, NUDOCS 8301140314
Download: ML20028C923 (4)

Text

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Washington Public Power Supply System U81 s l P.O. Box 968 3000GeorgeWashingtonWay Richland, Washington 99352 (509 Q5000 I Docket No. 50-397-- /)P 1 AEC Q.

December 30, 1982 G02-82-1025 lb* l l

Mr. R. H. Engalken Regional Administrator U.S. Nuclear Regulatory Commission Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 94596

Subject:

NUCLEAR PROJECT NO. 2 10CFR50.55(e) REPORTABLE CONDITION #219, IE CIRCULAR 81-05 SWAY STRUT / SNUBBER END BUSHINGS

References:

1. IE Circular 81-05

2. Telecon L.C. Floyd (Supply System) to J. Elin (USNRC),

dated December 2, 1982, same subject.

In accordance with the provisions of 10CFR50.55(e), your office was informed by telephone of the above subject reportable condition on December 2, 1982. Attachment A provides the Project's interim report.

We will continue to provide your office with quarterly updates on this subject. The next report will be submitted on or before March 20, 1983.

If there are any questions concerning this matter, please contact Roger Johnson, WNP-2 Project QA Manager, (509) 377-2501, extension 2712.

kRProgramabb Director, WNP-2 LCF/kd Attachments: 1. Interim Report

2. Figure 1 cc: W.S. Chin, BPA - Site A. Forrest, Burns and Roe - HAPO N.D. Lewis, NRC J. Plunkett, NUS Corp.

A. Toth, NRC Resident Inspector-(917Q)

Document Control Desk, NRC '

WNP-2 Files _

8301140314 821230 b

{DRADOCK 05000397

, PDR P

ATTACHMENT A WASHINGTON PUBLIC POWER SUPPLY SYSTEM NUCLEAR PROJECT NO. 2 DOCKET NO. 50-397 LICENSE NO. CPPR-93 IE CIRCULAR 81-05 SWAY STRUT / SNUBBER END BUSHINGS 10CFR50.55(e) CONDITION #219 INTERIM REPORT DESCRIPTIDN OF DEFECT OR NONCOMPLIANCE NRC IE Circular 81-05 addresses potential problems due to loose bushings on strut and snubber paddles. During the Project's evaluation of the. Circular it was discovered that inadequate assembly, lack of proper inspection / instal-lation criteria and material substitution may have occurred during installation of struts and snubbers.

SAFETY IMPLICATION If, due to improper engagement, inadequate assembly or material substitution, a strut or snubber does not function as assumed in piping / support analysis, the piping pressure boundary could fail under overstressed dynamic loads.

Although no instances of total disengagement were found, the Project has deter-mined this condition to be reportable under the provisions of 10CFR50.55(e) due to the extensive evaluation and potential rework required to correct exist-ing installations.

APPROACH TO RESOLUTION The Architect Engineer (A/E) initially contacted each involved vendor, request-ing a recommended response / resolution to the problems identified in IE Circular 81-05. In addition, a field review of snubbers and sway struts with self align-ing end bashing was conducted to ascertain the extent of the problem at WNP-2.

The results are summarized below for both large bore and small bore pipe.

Snubbers More than 100 snubbers were reviewed, either as-installed or in the warehouse, and it was determined that no bushing disengagement had occurred. The vendor (Pacific Scientific) confirmed that per their bushing staking procedure, no bushing disengagement should occur and due to the clearance between the paddle and clamp or bracket, it was physically not possible to have total disengage-ment. The A/E performed a review of all clamps and brackets approved for use with Pacific Scientific snubbers and found the maximum disengagement was within the manufacturer's allowables. Further, WNP-2 has installation instructions from Pacific Scientific which helps ensure proper installation of the snubbers.

On this basis, no further action need be taken on IE Circular 81-05 with regard to snubbers on WNP-2.

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, i Attachment A Page Two APPROACH TO RESOLUTION (Continued)

Struts

.The A/E reviewed approximately 30 installed struts and found partial disengage-ment did exist, however, no total disengagement was discovered. The vendors involved have indicated that disengagement should not occur if proper staking and installation procedures are followed. However, the vendors stipulated a partial disengagement of up to 33 percent of the bearing surface is toler-able (some vendors indicated a greater disengagement is tolerable, however 33 percent encompasses all cases).

The A/E performed a drawing review to determine the possibility of total bush-ing disengagement. This effort was complicated as the Engineer allowea inter-changing of selected vendor parts during installation. It was discovered that based on possible clearances between the strut paddle and clamp / bracket, it was physically possible to have total disengagement with a limited number of combinations (9 of 500, see Figure 1 attached) of struts and clamps or brackets, if the staking process as performed by the manufacturers was inadequate.

STATUS OF RESOLUTION Snubbers - No further action by WNP-2.

Struts To eliminate any possibility of complete disengagement and limit partial dis-engagement of the sway strut assembly from its paddle end bushing, a Project Engineering Directive (PED) has been issued directing the Mechanical Contractor to inspect and rework, as necessary, all previously completed rigid sway strut installations. To-date, there are 623 strut assemblies to be inspected. In addition, the contract specifications (Contract 215) have been revised to i include inspection / installation requirements for future installations.

In regard to possible material substitutions, a review by site personnel of installed conditions identified no occurrences of substitution of material.

PROJECT COMPLETION OF CORRECTION ACTION All required rework will be completed prior to system turnover on a system by system basis. In those instances where systems have been turned over, required rework will be completed prior to system operational testing.

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FIGURE 1 MATRIX OF POSSIBLE STRUT, CLAMP & BRACKET COMINATIONS AT WNP-2 PP: Power Piping G: Grinnell N: NPSI STRUT BRACKET CLAMP PP PP* PP~ PP* PP PP*

Size Old N H5142 H5146 N .G* Old New 400 N G I l ,

I I 1 ll l l

,1 X l ,

I X 300 300 '

X l

1. 15 y [

y X

X

'l j X I

1. 20/25 X X X

1. 40 X X X L

If strut (X) is combined with clamp / bracket marked (X) total disengagement could occur.

• Bracket and clamp combinations will not result in total disengagement.

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