IR 05000271/1985033

Insp Rept 50-271/85-33 on 851021-25.No Violations Noted. Major Areas Inspected:Preparations for Recirculation Piping Replacement,Including Work Instruction Packages,Welding & Welder Qualification & Training

ML20137L356
Person / Time
Site:	Vermont Yankee
Issue date:	11/21/1985
From:	Gray E, Wiggins J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML20137L349	List: IR 05000271/1985033 ML20137L343
References
50-271-85-33, NUDOCS 8512030424
Download: ML20137L356 (6)

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U.S. NUCLEAR REGULATORY COMMISSION

REGION I

Report N /85-33 Docket No. 50-271 License No. DPR-28 Licensee: Vermont Yankee Nuclear Power Corporation RD 5, Box 169 Ferry Road Brattleboro, Vermont 05301 Facility Name: Vermont Yankee Nuclear Power Station Inspection At: Vernon, Vermont Inspection Conducted: October 21-25, 1985

1. 8 Inspector: 1 o E. H. Gray, Lead React p gineer 'date Approved by: V/ #Y J. T. Wiggins, Chief, h //[t///f date Materials and Processes Section Inspection Summary:

Inspection on October 21-25,1985 (Report No. 50-271/85-33)

Areas Inspected: Routine, unannounced inspection of preparations for recirculation piping replacement including work instruction packages, welding, welder qualification and training, weld procedure review, observation of installation mockups and replacement of the regenerative heat exchanger. The inspection included 34 hours3.935185e-4 days <br />0.00944 hours <br />5.621693e-5 weeks <br />1.2937e-5 months <br /> on-site and 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> in the Region offic Results: No violations were identifie %h PDB O

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DETAILS 1.0 Persons Contacted Vermont Yankee Nuclear Power Corporation (VY) and Yankee Atomic Electric Company (YAEC).

G. Cappuccio, Engineer (Regenerative Heat Exchanger)

W. Finnel, Maintenance Foreman J. Gianfrancesco, Construction Supervisor R. Martin, QA Supervisor

• W. Murphy, Vice President and Manager of Operations

• J. Pelletier, Plant Manager D. Reid, Operations Superintendent A. Small, Construction Engineer K. Willens, Weld Engineer

• W. Wittmer, Recirculation Pipe Replacement Project Manager Morrison and Knudsen (M&K)

C. Chen, Project Weld Engineer W. Hawley, Welder Qualification Supervisor B. Jacobs, Lead Weld Engineer W. Robison, Radiographer

• Present at exit meeting on October 25, 1985.

2.0 Recirculation Pipe Replacement 2.1 Overview The Vermont Yankee Plant is replacing the reactor recirculation piping and residual heat removal (RHR) piping with nuclear grade type 316L stainless steel during the present outage. This inspection was conducted prior to removal of piping during welder qualification, preparation of work instructions and training of crafts on mockups for machining, welding, rigging and material handlin The fabrication and installation of the piping is to the ASME Code Section III,1980 Edition through Summer 1982 with welder and welding qualifications to the ASME Code,Section I The inspector conducted an on-site review of the preliminary activities directed toward replacing the recirculation piping. The specific areas sampled were:

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Installation procedure and documentation

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Site work instructions for removal and installation of suction and discharge piping, loop "A"

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Weld Procedures

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Welding training and qualification

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Weld ' equipment

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Weld wire issue and control

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QC Inspection of work in progress

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Mockups

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Radiography (RT) of welder qualification tests

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QA involvement in the pipe replacement program

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Control of pipe component lengths to minimize weld shrinkage effects on pipe system stresse Observations made in the above areas resulted in the inspectors conclusion that the licensee and the contractor have a program that anticipates many of the problems and pitfalls inherent in a major pipe replacement progra No violations were identifie .2 Procedure Reviewed Portions of the following recirculation piping program procedures or instructions were reviewe .4 Reactor Recirculation Decontamination AP696 Recirc Project Interface Procedure N-8-8-AB Stainless Steel GTAW Machine Welding I&T EDCR-85-1 Installation and Test Procedure EDCCR-85-1, Control of Recirc and RHR System Replacement SQP- Preparation, Control and Issue of Controlled Work Packages Work Package #1221 Install Recirc Suction Discharge Piping Loop "A" Work Package #1211 Remove Recirculation Suction Pipe Loop "A" FWP Field Weld Procedure-Control of Welding FWP Welder Qualification The work packages which were not fully approved at the time of this review had several areas of concern to the inspector including:

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Step 1240 of #1221 referenced note 9 which should be note This was a general conditio The spool sketches show dimensions which are theoretical final assembled dimensions from drawing 10P 122-863 but are not identified as suc The weld data card did not provide for a QC inspection hold point for ISI surface preparation prior to final R The weld joint preparation sketches, for example for Weld A-D-11, provide for inspection of remaining pipe wall thickness after counterbore but does not specify the required dimensio .

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In the area of welder qualification, positive identification of welders being tested while on a visitors badge, was not recorded by the weld test technicia .

The M&K weld engineer agreed to have identification verification of the welder noted on the welder qualification record for those welders being tested prior to issuance'of a site photo badge. Previously qualified welders have.been issued photo badges and have demonstrated proficiency in welding during subsequent test and mockup activit Adequate consideration and revisions were made by the licensee in response to the above observation No violations were identifie .3 Water Soluble Purge Paper In review of welding procedures and work instructions the planned use of water soluble paper as argon gas purge barriers for gas tungsten arc root pass pipe welding was noted. The water soluble paper separates in water into individual fibers approximately 1/4 inch in length and 5 microns in diameter which are reported to convert to carbon dioxide with time above 400 F. The Information Notice 85-13, consequences of using soluble dams, indicated a significant problem had occurred during the Monticello Plant recirculation pipe outage where paper fibers clogged the control rod drive mechanism (CRDM)

moveable inner filter resulting in reduced reactor scram speed. In discussion with VY engineering on the use of soluble purge paper during the VY outage the inspector was advised that the VY CRDM filters are the fixed type that would not reduce scram speed if clogge An M&K Laboratory report on the solubility of purge dam paper as a function of the paper to weld distance was reviewed. A written evaluation of the use or possible results of using soluble purge DAM material at VY was not available, leaving the following question ) Will fibers cause a problem with the CRDM filters or any other reactor coolant system component?

2) Does laboratory test data demonstrate that fibers decompose to CO 2 gas above 400 f, and at what rate?

3) During reactor system flow prior to heat-up above 400 F, where will fibers accumulate?

4) Is flushing of piping where soluble purge dams have been used a necessary procedure to reduce the number of fibers left in the system?

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The use of soluble purge dam paper is an unresolved item pending the VY written evaluation. (271/85-33-01)

2.4 QA Involvement in the Piping Replacement Projects Procedures SQP-5.2 (Work Packages) and AP6965.1 (Project Interfaces)

define responsibilities of the Project Quality Manager of the contractor and the Yankee Project Team Quality Assurance (PTQA) to assure the requirements of 10 CFD 50, Appendix B are met during piping replacement activities. The work packages are reviewed by M&K QA prior to release for review by the VY project team. The Yankee PTQA reviews each work package and defines VY hold point While M&K selects and performs required QC production inspections and is responsible for the ASME Code Section III Quality Assurance, the VY PTQA is responsible for project QA overview as achieved by surveillances, inspections and VY hold point In review of the QA involvement in the piping replacement program, discussions with QA team members and examination of QA records, no violations were identifie .0 Independent Evaluation The regenerative heat exchanger removes heat from the reactor water cleanup system stream as the water flows from the reactor coolant system into the nonregenerative heat exchangers and the filter demineralizer The design conditions of the regenerative heat exchanger on both the tube and shell sides are 1450 psig pressure and 575 F temperature and therefore, this heat exchanger normally does not experience tube surface boiling or significant pressure differential between the shell and tube side The inspector reviewed the VY FSAR Part 4.9 and drawing E7665 Rev 2 of the replacement regenerative heat exchanger constructed of type 316L stainless steel tubes and a stainless steel shell. The 162 tubes are 3/8 inch outside diameter with 18 BWG (0.048 inch) wall thickness. The tubes are bent with two 90 bends separated by several inches of straight tube to make a 180

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tur The VY Operational Quality Assurance (0QA) audit number 85-44, a vendor surveillance of the heat exchanger manufacturer, identified that solution treating of the tube bends had not been performed as required by the purchase order specification. The referenced ASTM Specification, SA 688 for welded austenitic stainless steel feedwater heater tubes identifies annealing (solution treatment) of U-Bends to be an optional requiremen The inspector reviewed the NCR 85-39 and results of the evaluation by the licensee to determine if tube bend solution treating is required for satisfactory regenerative heat exchanger service. The evaluation included materials engineering review by the licensee, Stone and Webster and a consultant. The conclusion reached was that the best option would be to

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install the new regenerative heat exchanger without solution treating the tube bends. As these tubes do not experience boiling, and therefore chloride concentration, have nearly equal internal and external pressure and are not part of the primary reactor coolant pressure boundary, and heat exchanger replacement at this time should result in an overall reduction of personnel radiation exposure. Based on these factors the NRC inspector could not disagree with the licensee's conclusio In summary, VY 0QA identified the omission of a design specified heat treatment on the new regenerative heat exchanger. This condition was entered into the non conformance system, evaluated by engineering, including consultants and found to not be likely to cause a service proble Should tube rupture or leaking occur, the result would be a slight bypass of water within the hear exchanger affecting thermal efficiency but not safet No violations were identifie .0 Unresolved Items Unresolved items are matters which more information is required in order to determine if they are violations or deviations. An unresolved item is discussed paragraph .0 Exit Interview An exit interview was held on October 25, 1985, with members of the licensee's staff as denoted in Paragraph 1 and the NRC Senior Resident Inspector. The inspector discussed the scope and findings of the inspec-tion. At no time during this inspection was written material provided to the licensee by the inspector.