ML18033B394

Safety Evaluation of Employee Concerns Re Welding

ML18033B394
Person / Time
Site:	Browns Ferry
Issue date:	05/31/1990
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML18033B375	List: ML18033B374 ML18033B376 ML18033B377 ML18033B378 ML18033B379 ML18033B381 ML18033B382 ML18033B384 ML18033B385 ML18033B387 ML18033B388 ML18033B389 ML18033B390 ML18033B392 ML18033B394 ML18033B395 ML18033B396
References
NUDOCS 9006210273
Download: ML18033B394 (10)

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).- 3 WASHINGTON, D. C. 20555 SAFETY EVALUATION REPORT BY THE OFFICE OF NUCLEAR REACTOR REGULATION EMPLOYEE CONCERNS RELATED TO MELDING TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT UNITS 1 2 AND 3 DOCKET NOS.

50"259 50"260 AND 50"296 INTRODUCTION The issues addressed in this Safety Evaluation Report (SER) for the Browns Ferry Nuclear Plant (BFN) are programmatic in nature and refer to procedural and/or organizational problems in the welding program.

This report addresses 63 individual employee concerns which are addressed by TVA in the following 13 Melding Project (WP) Employee Concern Evaluation Reports (ECER):

WP-01-BFN WP-02-BFN WP-03-BFN WP-04-BFN WP-06-BFN WP-07-BFN'P-11-BFN WP-13-BFN WP-16-BFN WP-24-BFN WP-25-BFN WP-32-BFN WP-35-BFN Control of Melding Filler Material Inspection of Melds Through Carbo-Zinc Primer Melder gualification and Continuity Availability of Inspection Tools Inspector Training and Certification Melder Training and Experience Surface Grinding of Melds Adequacy of Welding Equipment Structural Steel Preweld Inspection Welder gualification Weld Repair Not Heeting ASME Code Requirements Structural Support Welds Meld Inspection Procedures Most of the concerns were originally raised at the Watts Bar Nuclear Plant (WBN).

Of the 63 concerns considered applicable to BFN, 7 were specific to

BFN, 3 were specific to Bellefonte (BLN), 3 were specific to Sequoyah (SgN),

and 1 was non plant specific.

TVA determined that the remaining concerns considered were possibly generic, and therefore, applicable to BFN.

TVA established the Welding Project to formulate a program for each nuclear plant site to address the employee concerns related to TVA welding program.

For the Browns Ferry site, the TVA Welding Project is divided into two phases.

Phas. I is a review of the procedures, design output documents, and quality indicators (e.g.,

non-conformance reports, audit findings, NRC reports, etc.)

to determine if there are any problem indicators.

The Phase I Report was forwarded by a TVA letter dated February 6, 1987.

The WP Employee Concern Evaluation Reports evaluated the welding related employee concerns with a common issue(s) and were written on the basis of the Phase I 9006210273 PDR ADQCI(

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'a' la 5'lf1 CS Phase II included review of specific weld records (welder qualification, filler

material, inspector qualifications, etc.)

and a physical reinspection of specific weld populations whose samples were selected on an engineering and logic basis.

The Phase II Report was forwarded by a TVA letter dated March 7, 1988.

EVALUATION The NRC staff with Brookhaven National Laboratory (BNL) personnel as consultants has monitored the TVA WP Phase I 8 II efforts through inspections.

The same consultants have reviewed the 13 ECERs and prepared the attached Technical Evaluation Report (TER) entitled, "Browns Ferry Welding Related Employee Concerns Evaluation," MT-4001-1 dated Decembe~

1989.

The pertinent NRC inspections are addressed in the TER.

The staff has reviewed the TER and concurs in their bases and findings.

The staff believes.that there are five essential elements which must be func-tioning for a welding program to be viable.

BNL placed each of the individual employee concerns into one of these essential element categories.

A miscel-laneous category was established to cover those concerns which are not normally related to a welding program.

These program essential element categories are as follows:

, Welding Procedures Welder qualification/Training Welding Inspection Weld Design and Configuration Filler Material Control Miscellaneous There is one concern, BFN-85-019-001, which at the time of issuance of the BNL TER was not closed by TVA. It is being monitored by TVA's Corrective Action Tracking Document 50132-BFN-1.

The issue of this concern is that the adequacy of welds in supports and hangers is questionable.

The concern was substantiated in that the Phase II reinspection of structural supports at BFN revealed a

number of deficiencies in the welds.

The deficiencies were significant to the degree that some of the supports were not suitable for service, i.e., that rework and repair or modification was necessary to make the supports suitable for service.

In order to demonstrate that the welds in supports and hangers are suitable for

service, TYA determined in WP-32-BFN that additional weld evaluations of structural components needed to be performed.

Another result of the Phase II reinspection was that many structures, although adequate for service, demonstrated that TVA's implementation of the gA/gC program in the area of welding was ineffective.

The basis of this finding is as follows:

a significant number of deficient welds, or percentage of weld lengths inspected, had been found requiring engineering calculations to demon-strate their suitability for service, and that these calculations had not been performed during construction.

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~ The effectiveness of TVA's process for gC inspector training and qualification/

certification during plant construction and after operation was questionable in the area of visual inspection of welds.

The weld deficiencies discussed above should have been detected and corrective actions taken.

The weld deficiencies and other engineering problems found (loss of configura-tion control, unrecorded

loads, seismic design, etc.) lead TVA to an extensive and intensive seismic design program involving inspections,

redesign, repair and modifications of welded supports at Brown Ferry.

While the title of the program refers to "seismic design", the issues which are addressed encompass structural response to all loadings (pressure, temperature, dead and live loads, as well as seismic loads), structural integrity (presence and tightness of fasteners,

size, presence and location of welds),

and configuration.

0 To determine the adequacy of the various structural systems as built, TVA walkdown inspections of these systems recorded structural design information such as spans,

size, presence and configuration of members, presence and condition of mechanical fastening.

The seismic design program for the support systems initiated corrective actions to identify and address many deficiencies in these support systems, including weldment deficiencies.

For all but cable tray supports and electrical conduit supports, the size, presence and location of welds were determined and evaluated by calculations.

In response to NRC's questions about TVA not measuring all of the weld attributes for the two support'system seismic programs, TVA in a letter dated January 19, 1989 addressed this issue.

The staff has been monitoring this issue through inspections of the TVA s seismic design program.

The inspections which reviewed TVA's corrective actions for addressing the lack of weld data for these support systems are documented in the following NRC inspection reports.

(1)

Inspection Report 50-260/89-36 dated September 21, l989 (Small bore piping and instrument tubing)

(2)

Inspection report 50-260/89-42 dated February 26, 1990 (Seismic Design, para 3. 1(5) Cable tray supports)

These reports also address the other support system seismic design issues, including the weld information from the walkdown inspections.

Repairs or modifications were made as necessary to meet design requirements.

Inspection Reports 50-259/86-34, 50-260/86-34, 50-296/86-34 dated November 20, 1986 address torus modifications and associated weldment problems.

The staff finds the establishment of the seismic design program should address the presence of weld deficiencies in structural supports effectively, and closes employee concern BFN-85"019-001.

The staff concludes that TVA's seismic design program upon being adequately implemented, will demonstrate that the hardware and weldments in supports as constructed are suitable for service.

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CONCLUSION Based on the staff review of the attached TER concerning welding related employee concerns at BFN Unit 2, the staff concludes that TVA had adequately addressed these employee

concerns, and that their conclusions and corrective actions are acceptable.

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MT-4001-1 BROWNS FERRY WELDING RELATED EMPLOYEE CONCERN EVALUATIONS M. H.

SCHUSTER C. 3.

CZAQKOWSKI DECEMBER 1989

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