ML18030A028

Final Deficiency Rept Re Unauthorized Welding of Pipe Hanger to Reactor Pressure Vessel,Initially Reported on 800201.All Necessary Rework Has Been Completed.Reactor Pressure Vessel Is in Acceptable State

ML18030A028
Person / Time
Site:	Susquehanna
Issue date:	01/22/1981
From:	Curtis N PENNSYLVANIA POWER & LIGHT CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
10CFR-050.55E, 10CFR-50.55E, ER-100450, PLA-609, NUDOCS 8101270425
Download: ML18030A028 (7)

Text

TWO NORTH NINTH STREET, ALLENTOWN, PA. 18101 PHONEr {215) 770 5151 NORMAN W. CURTIS Vice President-Enpineerinp 5 Construction-Nucteer 770.5381 january 22,, 1981 Mr. Boyce H. Grier Director, Region I U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 SUSQUEHANNA STEAM ELECTRXC STATION FINAL REPORT OF A DEFICIENCY RESULTING FROM THE UNAUTHORIZED WELDING OF AN ATTACHMENT TO THE UNIT Il RPV ER 100450 FILE 840-4/900-10 PLA-609

References:

PLA-496 dated 06/13/80 PLA-446 dated 02/01/80

Dear Mr. Grier:

This letter serves to provide the Commission with a final report of a deficiency relating to the unauthorized welding of a pipe hanger to the Unit Nl reactor pressure vessel. The deficiency was originally reported in PLA-446. The information contained herein is submitted in compliance to the provisions of 10CFR50.55(e).

The attachment to this letter contains a description of the problem, its probable cause and significance and the corrective action taken. Although the condition warranted a significant amount of evaluation to insure that the adecpxacy of the vessel was maintained, it was determined that measures recgxired for the removal of the attachment did not have a detrimental impact on the safety or integrity of the reactor vessel.

We trust the Commission will find the information forwarded by this letter to be satisfactory.

Very truly yours, N. W. Curtis Vice President-Engineering a Construction-Nuclear

Mr. Boyce H. Grier January 22, 1981 FLW:sab Attachments cc Mr. Victor Stello (15)

Director-Office of Inspection a Enforcement U. S. Nuclear Regul'atory Commission Washington, D.C. 20555 Mr. G. McDonald, Director (1)

Office of Management Information & Program Control U- S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. Robert M.. Gallo U. S. Nuclear Regulatory Commission P.O. Box 52 Shickshinny, PA 18655

Attachments to PLA-609 DESCFZPTION OF DISCREPANCY NCR-5241 was issued on 1/25/80 to identify a noncompliance to Specification M213, Revision 7, related to small pipe hanger installation. Hanger 19 on Hanger Iso Drawing SP-DCA-137-4H, Revision 0 was not installed in the orientation and location intended by the design engineer. Ztem 2 (4" x 10'"

x 6" plate) identified on Standard Detail SPA 804 was welded on the Reactor

'ressure Vessel (RPV) instead of being installed .on the Biological Shield liner plate.

CAUSES

l. The causes. contributing to this deviation were determined to be human error compounded, by the fact that the construction drawings were unclear. The installation orientation was misinterpreted by both the installers and the-responsible Field Engineer, resulting in improper mounting of the pipe support in a horizontal position rather thon vertical (see Figure 1.)

Th'is involved. welding the pipe support to the RPV'rather than attaching to the top of the Biological Shield as the designer intendedA it

2. Zt appears that the Small Pipe Hanger Engineer failed to perform the walk-down required by FP-P>>ll> Paras. 6.2.2 and 6.2.3 and he failed to perform a conscientious investigation regarding the concerns of the pipefitter foreman+

3. Construction management failed to post adequate notice of restrictions, i.e.. for work on or around the reactor vessel. Construction management had, however, met its commitment in response to NRC Inspection Report 50-387/79-01 and GE letter EAG-1039, dated 2/2/79, to alert its the need for caution, while working near or around the vessel.

supervision'o REMEDIAL ACTION In response to NCR-5241 and Bechtel letter M-1-1397 dated January 31, 1980, General Electric issued FDDR-KR1-193 'to cover removal of the hanger and attachment weld and;to remove the heat-affected material from the RPV surface.

Following completion of this portion of the work, as-built data of the vessel surface and wall thickness were forwarded to GE/NEBG for final dispositioning of the FDDR and NCR.

Thickness measurements by means of UT have been taken of the RPV wall where Hanger H19 had been attached by welding. They indicate an existing minimum wall thickness of approximately 6-7/16 inches (excluding cladding thickness) vs. a 'minimum specified wall thickness of 6-3/16 inches. This provided sufficient excess wall to permit removal of the weld and without need for a welL repair. Blending and NDE of the RPV surface heat-affected'one was all that was required for the final disposition of FDDR-KR1-193. .

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The Field initiated FCI-M-180 to describe this ASME Section ZI repair of the vessel surface and its approval by PP&L (including PP&L's ANI), GE/NEBG

'nd Bechtel was obtained by June 30> 1980. Completion of the initial works submittal of the as-built data, reissurance of FDDR-1QQ.-193, and reapproval of FCI-M-180 by all applicable parties was accomplished by July 7, 1980.

Also, completion of the repair, close>>out of NCR-5241 and submittal of final as-built data to GE/NEBG was accomplished by August 7, 1980.

ACTION TO PREVENT RECURRENCE Letter M-1-1414 dated February 11, 1980 recgxests permission from General Electric to paint, permanent signs on the RPV's stating:

REACTOR VESSEL DO NOT BURN OR WE%)

ON VESSEL Bechtel, with GE concurrence, put up the'se permanent signs on the exposed surface of Unit 1 and Unit 2 RPV above the reactor shield by March 7, 1980.

To prevent similar occurrences on other susceptible ecpxipment and components (including other NSSS items), Bechtel compiled a list of components and investigated aCceptable methods of posting similar precautionary notices on such components in, both Unit 1 and Unit 2. Also Bechtel verified that the posting of such notices was completed and included as a monitoring activity in .their storage and maintenance program.

To ensure that all craftsmen are made aware of the restrictions on arc

~ strikes, welding or grinding on completed equipment or components, the subject was reviewed with the applicable foremen and general foremen at a series of weekly safety meetings that were completed February 29, 1980. Also at the meetings, the instructor further stressed. the importance and necessity of continuing to obtain assistance and direction from Field Supervision and Field Engineering whenever there is the slightest doubt concerning work to be performed, and if the direction received did not seem proper, personnel should continue to pursue the matter.

A memo was sent to all Lead Field Engineers by the Project field Engineer on February 7, 1980, requiring training sessions to be held by each discipline.

Field Engineers were reminded of their responsibility to perform adequate investigation and research for all problems which confront them and they were advised of the need for accurate and explicit engineering instructions to prevent similar situations from occurring. The Field Engineer responsible for hangers on night shift. at the time this incident occurred has been replaced by a person more experienced in design and installation of pipe hangers.

In order to prevent: delays in notification of potentially reportable situations,

. a memo from the Project Field Engineer to the Lead Engineers reminded them of the requirement to notify the appropriate supervisors of any deficiency which may involve a reportable condition. 'This subject was also addressed in the discipline training sessions. Lead Quality Control Engineers were directed by Project Quality Control Engineer to immediately report any potentially reportable condition to him, and to instruct all their personnel with regards to the recpxirements for immediate notification. This subject was also addressed at. a Quality Control training session on NCRs held on February 8, 1980.

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CGNCLUSION As of the release of this report:, all necessary rework has been completed and the Unit l RPV is in an acceptable state as confirmed by the NSSS.

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