IR 05000320/1978012

IE Insp Rept 50-320/78-12 on 780306 & 15.Noncompliance Noted:Welding Performed W/O Approved Welding Procedure & Cutting of Rebar Not Approved by Engineering Dept

ML19220B452
Person / Time
Site:	Three Mile Island
Issue date:	03/29/1978
From:	Gallina C, Mcgaughy R, Narrow L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML19220B444	List: IR 05000320/1978012 ML19220B447
References
50-320-78-12, NUDOCS 7904260151
Download: ML19220B452 (8)

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U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT

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Region I Report No.

50-320/78-12 Docket No.

50 320 Category B

License No. DPR-73 Priority

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Licensee:

Petropolitan Edison Ccmoany P. O. Box 542 Readino, Pennsvivania 19603 Facility Name: Three Mile Island Nuclear Station, Unit 2 Investigation at: Bainbridge, Pennsylvania and Middletown, Pennsylvania I

1stigation conducted: March 6 and 15, 1978 4[b4s/

3/ 2 7 [7 A-Investigators:

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'L. Narrow, Reac* r Inspector

'date ' signed hwha 0, ad L 3 29 1g C. O. Gallina, Investigator cate signed

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G. A. Walton, Reactor Inspector date signed bN fih.R

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Aporoved by:

w cate signed R. W. McGaugny,$niEf, Projects Section Reactor Constructio'n' & Engineering Support Branch Inve5tication Sumary:

Invest 1 cation on February 28, March 6 and 15,1978 (Recort No. 50-320/78-12 Investigation of an allegation tnat recar nac ceen cut Areas investicatec:

witnout proper authorization and extensions had been welded to studs without This investigation involved 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> on site by two NRC approved procedures.

inspectors and one NRC investigator.

Results: The allegation was substantiated and one item of noncompliance was acentified.

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TABLE OF CONTENTS Page A.

Introduction

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Allegation

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Sunr.ary of Findings

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Details of Investigation 4-7 1.

Persons Ccntacted

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Allegation 4-7 3.

Exit Interview

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References

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INTRODUCTION A.

The purpose of this investigation was to determine the validity of an allegation that a structural steel anchorage had been modified without approved procedures.

ALLEGATION B.

The alleger stated that, in order to install a structural steel anchor in a vertical wall within the reactor building, he had been required to flame cut rebar in the wall and then to weld lengths of 3/4-inch threaded rod' to 1-1/4 inch threaded rod which were to be in-stalled in expansion anchors within the wall. The individual stated that we?iing was performed without an approved welding precedure and expressed the opinion that cutting of the rebar.had not been approved by engineering and neither QC nor engineering was informed of this work..The alleger stated that this was a single, isolated instance.

SUMMARY OF FINDINGS C.

The allegation was substantiated.

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Details 1-Persons Contacted General Public utilities Service Corporation

• T. R. Block, QA Auditor W. T. Gunn, Site Project Manager

• S. Levin, Project Engineer Nuclear Energy Services, Inc.

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• '_. Reynolds, level I Inspector

• C. W. Thompson, Level II Inspector

• denotes those present at exit interview.

2.

Allegation Allegation as Understood by NRC It was alleged that holes had been drilled into the <.oncrete until reinforcing steel (rebar) was encountered at a depth of'approximately 2 inches.

At thct point the alleger was instructed to cut the rebar by " air-arc" burning. Thereafter he was instructed tc weld 4-inch lengths of 3/4-inch diameter threaded rod to 4-inch lengths of 1 1/4-inch diameter threaded rod.

It was his understanding that about eight or ten of these rods would attach an anchor plate to the con-crete using expanding concrete anchors. The alleger tncught that this work had become necessary because an embedment had inadvertently been omitted.

No drawings or procedures were available for cutting the rebar or for welding the threaded rod.

The welding rod used for this work had been drawn for welding on temporary air and inert gas lines adjacent to this work.

The alleger stated that the work in question had been performed in June or July,1973., At that time he had objected to performance of the work without procedures.

Performance of the work in this fashion had been of concern to him since that time and he had. finally..d'ecided

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that the NRC should be informed.

The alleger knew of no other examples of improper work.

Stace and P.ethod of Investigation

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The investigation was undertaken to determine:

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the identity of the anchor plate;

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I the possibility of other similar installations;and,

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whether the work had been performed in accordance with

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g approved procedures and under QC control.

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The investigation consisted of:

discussions with the alleger and licensee personnel;

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review of applicable documentation including Deviation

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Reports (DRs) and Engineering Change Memos (ECMs); and, visual examination of structural anchors and attaching studs

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and ultrasonic examination (UT) of the studs.

NRC Findings Discussions with the' alleger indicated that the probable location of the anchor plate in question was on the outer face of the southwest quadrant of the secondary shield wall at approximately Elevation 320. Observation of anchors in this area identified three anchor plates which supported the structural supporst for Core Flood Tank CF-T-1B a ' which were attached to the concrete with 3/4-inch studs:

oc Elevation 329'-10" and two at Elevation 315'-9".

On the basis of the information available, it appeared that it might be possible to identify the plate in question by two means.

First, a plate allegedly was installed using studs where plans originally specified an embedment. Second, ultrasonic examination of the studs should indicate the. presence of welds.

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DR No.125 showed the required embedment at Elevation 329'-10" as not installed. This DR was dispositioned by installation of a plate using expansion anchors in accordance with ECM No.1165.

The disposition was verified June 26, 1973. UT examination of the studs attaching this plate to the wall was performed by

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Nuclear Energy Services, Inc. and revealed no indication of welds.

It was concluded that this was not the plate in question. There were rm other examples nearby where a plate with studs had been installed instead of an embedment.

At NRC request, the alleger acccmpanied NRC inspectors to the site.

He selected the two anchor plates at Elevation 315'-9" as suspect

' but could not identify which anchor he had worked on.

Each of these anchors were attached by six 3/4-inch diameter scuds.

Both of these plates appeared to be installed ir accordance with plans, in that embedments had not been specifiec.

UT examination of the twelve studs was performed by Nuclear Energy Services to determine their length and whether the bolts had extensions welded to them. The tests were witnessed by the NRC inspector.

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The instrument used was a Sperry, Model UJ ccupied to a 5 PFZ The personnel performing the examination were quali-transducer.

fied in accordance with SNT-TC-1 A to Level II and I.

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Calibration was performed on a 4-inch bolt, threaded on the surface to simulate actual conditions. The first back reflection was set to approximately 90 percent full screen height.

The east support plate showed studs with lengths of 5, 4-3/4, No additional signals 4-1/2, 5-3/4, 4-1/2 and 5-5/8 inches.

throughout the stud lengths were shown which might indicate the presence of welds.

Examinations of studs in the west support plate showed the folicwing signals:

Stud Lenoth_

First Signal Second Signal 1.

5-1/2 inches 4 inches 4-3/4 inches 2.

6-1/4 inches (No intermediate reflections.

20% back reflection - front surface not square)

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4-3/4 inches 3-1/4 inches

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5-5/8 inches 4 inches 4-3/4 inches 5.

5-1/2 inches 4 inches 4-3/4 inches 6.

4-3/4 inches 3 inches 3-3/4 inches inccmpletely fused welds at These signals are indicative of the first signals and reflections frcm welds nct blended smoothly The at the outside surface of the studs at the second signals.

results of the examination also indicate that it is highly prob-able that installation of studs of the lengths shown and usirg expansion ancnors for 1-1/4 inch studs would have required cutting Examination of documentation by the NRC inspector of rebar.

failed to identify any engineering change or QC records.cf instal-lation of this anchor plate other than as shown on B&R Drawing No. 4205, Revisien 5.

Failure to install the anchor plate in accordance with Drawing No. 4205 and welding of the studs without an approved welding procedura all without engineering approval and/or QC acceptance is considered to be in noncompliance with 10 CFR 50, Appendix B, (

Criterion V (78-12-01).

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It appears probable that rebar has been cut in the vall behind this anchor plate, although evidence to substantiate this fully,

was not obtained. This is considered to be an unresolved item pending either evaluation of the effect of flame cut rebar on the structural integrity of the wall, or evidence that the rebar has not been cut (78-12-02).

During discussions with the alleger and in response to questions by the NRC inspector the alleger stated that he was not aware of any other areas where installed rebar may have been cut or of other similar instrllations of anchor plates.

UT examination of the other two anchor plates referred to above supported the.allegor's statement.

Conclusions

The allegation was substantiated.

UT examination of the studs for the west support plate (Elev. 315'-9")

for core flood tank CF-T-1B provides indications which are considered

to identify welded jointfin five of the six studs.

The size and length of the studs makes it highly probable that cutting of rebar would have been required.

Documentation evidencing engineering and/or QC control of this work could not be identified.

No indications were identified of additional improper installations of this type.

Corrective Action

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The licensee is investigating the possible effect of the rebar being cut on the structural integrity of the secondary shield wall as well as the adequacy of the installed anchor plate for its design loading.

3. ' Exit Interview

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The inspector met with licensee representatives (denoted in Paragraph 1) at the conclusion of the investigation on March 15, 1978.

The inspector sur:carized the scope and findings of the investigation.

The licensee representative discussed corrective action under consideration.

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References

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B&R Orawing No. 4154, Revision 6 B&R Drawing No. 4E05, Revision 5

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ECM No. 1165 I'Rs Nos.101 to 200 O

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