IR 05000327/1986009
| ML20154R004 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 03/13/1986 |
| From: | Blake J, Cortland P, Crowley B, Danni Smith NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20154R003 | List: |
| References | |
| 50-327-86-09, 50-327-86-9, 50-328-86-09, 50-328-86-9, NUDOCS 8603240205 | |
| Download: ML20154R004 (18) | |
Text
pA h UNITED STATES
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NUCLEAR REGULATORY COMMISSION
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Report Nos.: 50-327/86-09 and 50-328/86-09 Licensee: Tennessee Valley Authority 6N38 A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Docket Nos.: 50-327 and 50-328 License Nos.: DPR-77 and DPR-79 Facility Name: Sequoyah 1 and 2 Inspection Conducted: January 21-24 and 28-30, 1986 Inspectors: N. M [Ad
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3hJhd B. R. Crowley cr F
Date Signed R. A' 6tevlu A,
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D. E. Smith
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Date Signed b k.
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3Y)3 Wl:>
P. Cortland
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Da'te Signed
Accompanying n
J. 31 A lake, January 23 and 4, 1986 j
Approve by si nm-J //3
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J.' Biake, Tection Chief ptepgned Engineering Branch Division of Reactor Safety SUMMARY Scope:
This special, announced inspection involved 119 inspector-hours on site to evaluate TVA's welding review program for Sequoyah.
The areas reviewed /
observed included Bechtel audit activities, TVA reinspection activities,
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qualification of Bechtel and TVA audit and inspection personnel, assessment of the TVA phase 1 plan and review of the APtech study.
Results: No violations or deviations were identified.
8603240205 860319 DR ADOCK 050
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REPORT DETAILS 1.
Persons Contacted Licensee Employees
- P. R. Wallace, Plant Manager
- L. E. Martin, Project Manager - Staff of Deputy Manager, Nuclear Power
- J. W. Coan, Project Manager - Welding Project
- R. W. Olson, Sequoyah Modifications Manager
- S. P. Stagnolia, Construction Programs Project Engineer - Welding
- G. J. Pitzl, Operations Programs Project Engineer - Welding Project R. M. Jessee, Engineering Programs Project Engineer - Welding Project H. S. Beckner, Audit Cooridnator - Welding Project M. E. McCrary, Section Manager - QC NDE Training Section J. H. Fox, Supervisor, Welding and Materials Section - Operations D. H. Mickler, Coordinator
- R. Bentley, NDE Engineer
- T. T. Gilbert, ISI Unit Supervisor Other licensee employees contacted included QC inspection personnel, engineers, construct personnel, health physics personnel, security office members, and office personnel.
Other Organization
- A. M. Vuksan, Audit Team Leader, Bechtel Corporation
- D. R. Cady, NDE Level III Examiner, Bechtel Corporation M. J. Dutru, NDE Level III Examiner, Bechtel Corporation NRC Resident Inspectors
- K. Jenison, Senior Resident Inspector
- L. Watson, Resident Inspector
- Attended e.it interview 2.
Exit Int & w The inspection scope and findings were summarized on January 24 and 30, 1986, with those persons indicated in paragraph 1 above.
The inspector described the areas inspected and discussed in detail the inspection findings. No dissenting comments were received from the licensee.
Inspector Followup Item 327, 328/86-09-01, Applicable Codes for NDE of Pipe Welds - paragraph 5.b.(2).
i Inspector Followup Item 327, 328/86-09-02, Revision of MT Procedure to Provide for Calibration of MT Yoke - paragraph 5.b.(2).
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Inspector Followup Item 327, 328/86-09-03, Clarification of Terms " Adequate for Service" and " Meets All Requirements" Relative to TVA Welding Program -
paragraph 5.d.
Inspector Followup Item 327/86-09-04, PT Inspection of Weld 1AFDF-92C -
paragraph 5.b.(3)(c).
The licensee did not identify as proprietary any of the materials provided to or reviewed by the inspector during this inspection.
3.
Licensee Action on Previous Enforcement Matters This subject was not addressed in the inspection.
4.
Unicsclved Items Unresolved items were not identified during the inspection.
5.
Sequoyah Welding Program Evaluation Due to a number of specific and general allegations / concerns relative to the adequacy of TVA's welding program, TVA determined that additional reviews were needed to determine the adequacy of the TVA welding program and..TVA welds.
A Welding Project was formed within the Office of Engineering to resolve current welding issues and determine actions to be taken to ensure that future welding activities are in accordance with TVA commitments.
In the NRR public meeting on TVA Welding Issues on January 7, - 1986, TVA outlined their plan to resolve all welding issues.
Included was an action plan for each site consisting of the following:
PHASE I Review TVA commitments to NRC
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Verify that written program reflects commitments
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Assemble quality indicators of " Welding Concerns" by type and plant Trend and evaluate effect of " Quality Indicators" on
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programs
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Issue adequacy statement regarding written programs to implement / control welding PHASE II
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Perform welding program implementation audit Construction Program Implementation Operations Program Implementation
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Evaluate need for additional reinspections
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Impleraent any additional reinspections and deficiency resolutions (both individual and generic cases)
Welding project will issue final reports, each plant j
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TVA made the decision to reinspect a sample of welds at the Sequoyah site.
On January 17, 1986, TVA. submitted their " Welding Program Description" and Welding Related Activities Action Plans for Sequoyah, Units 1 and 2 and Watts Bar Unit 1.
During the period January 21-24, 1986, a NRC team consisting of B. R. Crowley (Region II), D.
E. Smith (NRR), and P. Cort. land (I&E)
performed an on-site review / observation of audit and reinspection activities of TVA and their contractor (Bechtel Corporation) as detailed in the paragraphs below.
A followup inspection was performed on January 28-30, 1986 by B. R. Crowley (Region II).
a.
Bechtel Audit Activities To satisfy phase II of the TVA action plan, TVA hired Bcchtel to perform an independent welding program implementation audit.
The inspectors reviewed Bechtel's audit program as described below.
The review included review of objectives, organization, internal procedures and policies, responsibilities, sampling methodology, and populations sampled.
(1) Documents Review
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"TVA Program Description" submitted to NRC on January 17, 1986.
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" Welding Project Program Description - Audit Work Plan" submitted to NRC on January 17, 1986 Bechtel " Audit Plan for Sequoyah Nuclear Power Plant"
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Bechtel Quality Audit Checklist "TVA 01-N0", Revision 0, dated January 13, 1986
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Bechtel Quality Audit Checklist "TVA 01-0C", dated January 13, 1986
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Item 17 in the Bechtel package, Reactor Cooling Pump Plat-form, including Maintenance Request MR AS45951 Welding Procedure Specification GT-88-0-1
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Procedure Qualification Record PQR-GT 88-0-1 EP 3.13 Engineering Document
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(2) Organization The Bechtel audit was performed at the direction and under the general management of the TVA Welding Project Manager.
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Bechtel audit team consisted of four auditors and one lead auditor. TVA personnel assisted as necessary.
(3) Sample Selection and Size TVA specified the minimum number of items to be examined for the two TVA organization to be audited (Office of Nuclear Operations and Office of Construction) and the systems / structures to be audited.
Bechtel selected the specific systems / structures to be audited.
The guidelines on selection included the stipulation that the items to be audited be safety-related in order to have meaningful records. This criteria usually meant that class 1 or 2 systems were required.
In addition, " employee concerns" were
. considered in the selection process.
Bechtel reviewed all
" employee concerns" related to welding and considered them significant if the concerns would potentially affect the safety-related portion of the plant and enough information was provided to perform the audit (Bechtel intends to examined all welding-related " employee concerns" whether significant or not).
One or more packages were selected from each major system with -
emphasis on the Main Steam Loops.
Seventeen packages were
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selected, each included one or more weld joints and all of the joints in the package were reviewed (see Table 2 of Bechtel's Audit Plan for Sequoyah Nuclear Power Plant).
In addition, five welds from the TVA reinspection program (see paragraph b. below)
were added to the audit plan. A random selection was attained by having different team members select one of the eligible welds that appeared on the layout for the specific system. Each of the five team members had several areas to review in all of the packages; no one member reviewed an entire package.
The items selected for audit covered the entire time span of construction and operations.
The welds selected corresponded with the welding fabrication effort in that a high proportion of the welds (about 40%) were fabricated during the -period of maximum construction effort.
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Records reviewed far exceeded that required in the Bechtel Audit Plan.
An increased sample of the following records was included in the audit:
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NDE Examiner Certification Records Welding Qualification Records
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Welding Material Qualification Records
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Welding Procedures and Support PQRs
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NCRs For audit of Nonconformance Reports (NCRs), the auditors randomly picked 20 welding related.NCRs out of approximately 200.
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(4) Audit Elements The key elements of the Bechtel audit were specified as follows:
Implementation of technical and welding program requirements
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Adequacy of design output documents Initial welder or welding operator qualifications
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Maintenance of welder or welding operator qualifications
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Renewal of welder or welding operator qualifications Initial welding inspection personnel qualifications
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Maintenance of welding inspection personnel qualifications
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Renewal of welding inspac. tion personnel qualifications
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Use of appropriate welding procedures
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Use of appropriate inspection procedures
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Use of appropriately trained and qualified personnel
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In-process control of welding
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Documentation of the above activities
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Nonconformances and corrective actions Training programs adequacy
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Additional areas of concern as determined by a review of employee concerns (5) General Observations
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The NRC inspectors made the following observations:
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Bechtel is competent to perform an audit of the TVA QA system in the areas.of welding.
Audit personnel had many years of experience and the level of experience was appropriate for the task and met or exceeded the audit work plan require-ments.
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Although the audit is programmed, to determine applicability by engineering judgement, the random selection and extensive numbers of records reviewed should provide part of the basis for resolving some of the major welding issues.
Bechtel was reviewing the documents related to a specific
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package to verify that the documents specified were present.
The documents reviewed included qualification and certifica-tion records of the welders.and inspectors identified in the packages.
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Bechtel was not determining if the documents were administra-tively correct and technically suitable for the application.
This was by design as TVA stated in note 1 on page 4 of the
Welding Project Program Description - Audit Work Plan, "The technical or engineering adequacy of the design output documents is not to be -researched; their adequacy is to be u
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4 checked in the. sense of completeness of'information for the.
organization or individual who must use the document to continue - forward with the program."
TVA and Bechtel indicated that the-idea' was to perform an implementation audit to insure that where the program required a document,
'l the document was present and complete but the adequacy of the document was not to be researched.
Bechtel was not performing any type double-check of their own
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work and stated that their people were competent and-the j
nature of the work did not: require double-checking. Further.
investigation, revealed that a sort of double-check was being
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performed, although not being documented.
During the NRC
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inspection, Bechtel decided - to institute a syste:n of docu-j mented double-checks.
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The training program audit was in -terms of the training
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i requirements of the time as stated in TVA documents and not
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j the adequacy ~ of the training.
For VT examiners, a 32 question test was given and test papers were available.for the examiners audited. As documentation of the general level of skill, for the examiners whose records were audited, all except one was qualified for MT/PT.
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TVA Reinspection Programu.
- The final Sequoyah reinspect' ion plan, as implemented at the site,'is included as Attachment 2 to Enclosure 2 to.the TVA submittal to the NRC dated January 17, 1986, and is identified as "Sequoyah Reinspection of t
Selected Welds - Reinspection Plan", R1, January 16, 1986.
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i In accordance with the Reinspection Plan, the ' applicable codes are as
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follows:
Structural Steel and Support Welds - NCIG-01, " Visual ~ Weld
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Acceptance Criteria for Structural Welding-at -Nuclear Power Plants"
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Piping Welds - USAS B31.1 (1967-~ Edition) or USAS B31.7 (1969
- Edition with 1970 Addenda) as applicable The team reviewed / examined / observed the following relative 'to the reinspection. activities:
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(1) Plan Review
The reinspection plan was reviewed. - In general, the' plan required physical - reinspection (NDE including visual) of approximately'100 -
welds in each of the following~ categories or groups:.-
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4 Group 1 Selected piping and attachment welds in-Class 3 and ANSI L
B31.1' systems (ERCW, CCW, and AFW) at various elevations i
in the auxiliary building.
The sample will include carbon and stainless steel lines.
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Group 2 - Welds of supports for piping (relative to above lines).
Group 3 - Welds of cable tray supports and conduit supports in the Auxiliary Building.
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Group 4 - Structurally significant welds on miscellaneous struc-tural steel in the Auxiliary Building.
Group 5 - HVAC support welds in the Auxiliary Building.
In addition, butt welds were visually examined for a portion of spiral welded pipe used as ductwork (Group 6).
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For structural steel and support welds, the plan specified that the principle attributes to be addressed were the presence, size,
length and location of welds.
In addition, structurally signi-ficant weld discontinuities detected through coatings were to be-
reported.
The generic type of filler metal, austenitic (non-magnetic) or ferritic (magnetic), was reported..
For piping welds, the NDE inspection was to be that required by
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the construction code of record.
Visual inspection was-to be applied to all welds and the. generic type of filler material was to be checked.
(2) Procedure Review The inspectors reviewed the following NDE procedures being used to
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inspect the welds listed in paragraphs (3), (4), and (5) below.
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N-MT-1, R4, " Magnetic Particle Examination of Nuclear Power Plant Components"
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N-VT-6, R0, " Visual Examination of Structural' Welds Using the i
Criteria of NCIG-01" N-PT-1, R6, " Liquid Penetrant Examination Using the Color
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Contrast Solvent Removable Method"
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N-VT-3, R4, " Visual ' Examination. of Weld ' Ends, Fitups, and Dimensional Examinations of Weld Joints"
The procedures.were not reviewed. to make a. detailed comparison with code.-requirements, but.- to verify that in general, the-procedures comply with requirements and were adequate. to perform the required inspections.
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During review of the procedures, the inspectors r ated that procedures N-MT-1 and N-PT-1 were written to ASME Boiler and Pressure Vessel Code, Sections III and XI.
Hovtver, the
" criteria" paragraph, page 5 of.the R1,1/16/86 et ition of the
"Sequoyah Reinspection of Selected Weld - Reinsp ection Plan" specifies that, " Pipe welds will be reinspected to the B31.1 (1967 Edition) or B31.7 (1969 Edition with 1970 Addenda) code of record using the visual and nondestructive examination methods (other than volumetric) and acceptance criteria." TVA agreed to evaluate this apparent conflict and insure that the codes specified in the inspection plan were being met.
Pending review of TVA's evalua-tion, this matter is identified as Inspector Followup Item 327, 328/86-09-01, Applicabic Codes for NDE of Pipe Welds.
In addition, the inspectors noted that procedure N-MT-1 did not
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provide details for checking calibration of the NT Yoke.
During observation of MT inspection (see paragraph (3)(a) below), the inspectors noted that the yoke was being calibrating even in the absence of procedure requirements.
At the conclusion of the NRC inspection, TVA was in the process of revising procedure N-MT-1 to provide details for checking calibration or the MT Yoke.
Pending review of the revised procedure, Inspector Followup Item 327, 328/86-09-02, Revision of MT Procedure to Provide for Calibration of MT Yoke, is identified.
(3) Observation of In-Process Inspections (Piping)
(a)
In-process magnetic particle (MT) inspection of the following welds was observed and compared with applicable procedure (N-MT-1,R4):
Weld Size System Class 1-AFDF-33 8"
0ER-1995E 24" Emergency Rawcooling
Water (b)
In-process visual (VT) inspection of the following welds was observed and compared with applicable procedure (N-VT-3, R4):
Weld Size System Class CBT-1WP 3"
Chemical Batch Tank TVA-G-CBT-2WP 3"
Chemical Batch Tank TVA-G CBT-3WP 3"
Chemical Batch Tank TVA-G (c) In-process liquid penetrant (PT) inspection of the following welds was observed and compared with applicable procedure (N-PT-1,R6):
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Weld Size System Class 2AFDF-25AA 4"
2AFDF-25BB 4"
10C-1979 2"
Component Cooling
1CC-1980 2"
Component Cooling
1CC-1981 2"
Component Cooling
1CC-2091 2"
Component Cooling
1CC-2092 2"
Component Cooling
1C0-2147 2"
Component Cooling
1CC-2148 2"
Component Cooling
1AFDF-92A 4"
1AFDF-928 4"
1AFDF-92D 6"
1AFDF-92E 6"
Vendor certification records for the foll(xing penetrant materials used to inspect the above welds were reviewed:
Material Type Batch Nos.
Cleaner / Remover SKC-NF/ZC-7B 85E048, 83M066, and 85D017 Penetrant SKL-HF/S 830030
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Developer SKD-NF/ZP-98 850020 and 82L010 During observation of PT inspection of welds 1AFDF-92D and 92E, the team noted that weld 92C in the same line had been cleaned for PT but appeared to have an inadequate surface for PT inspection.
The weld had some minor surface preparation, but was generally in the as-welded condition and was very rough.
A later review of the inspection, documentation for the current reinspection revealed that the PT examiner had -
rejected the weld for linear indications caused by. inadequate surface preparation.
However, review of the original fabrication documentation from 1984 revealed that the weld had been PT inspected and passed.
In addition, tiie original fabrication documentation indicated the weld was welded using the GTA process.
The rough surface of the weld gives the appearance of a.SMA process _ weld. TVA was in the process of evaluating questions relative to this weld at the conclusion of the NRC inspection.
Pending review of TVA's resolution to this problem, Inspector Followup Item 327/86-09-04, PT Inspection of Weld 1AFAF-92C is identified.
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(4) Observation of In-process Inspections (Spiral Welded Air Ducts)
In field butt welds for spiral welded air ducts, TVA inspectors noted a number of circumferential butt welds that appeared to be welded less than 360 when viewed from outside the duct.
The areas that appeared not welded were a few inches in length next to the reactor building wall which were inaccessible when the ducts were installed.
TVA's construction personnel recalled that during construction when a portion of a weld was inaccessible, access was gained to the inside by either cutting a window in the duct or through a manway and the inaccessible portion welded from the inside.
The team observed the following four typical areas in the purge air system in the Unit 2 reactor building annulus that appecred to be welded Icss than 360*:
Area 1 330 Az
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687' Elev.
24" duct Area 2
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83 Az 702' Elev.
10" duct Area 3
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75 Az 702' Elev.
10" duct Area 4
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10 Az 705' Elev.
24" duct Evidence existed on the ducts, i.e., nearby welded closed windows, to indicate that access had been gained to the inside.
Later during the inspection, TVA cut inspection windows in the ducts near the four areas listed above to verify that areas that appeared to be unwelded were actually welded on the inside. The inspectors observed the welds inside the ducts in the four areas noted.
(5) Observation of In-process Inspection (Supports)
The inspectors observed in-process visual inspection of the following support welds:
Package 27 - HVAC Support, 47A920-28-1, 1A, 18 i
SM1-0-317-24-27 Sheets 1, 2, and 3 Elevation 734 (approxi-mately 34 welds)
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Package 28 - Conduit Support Elevation 734.(approximately 21 welds)
The TVA examiners carefully and thoroughly examined every weld for defects detectable through paint.
In case of doubt, as in the length of welding slag, the paint was removed by scrapping.
The examiners documented indications in writing and used sketches and photographs. The paint thickness was also measured. The examina-tion criteria used for structural welds was the Visual Weld Acceptance Criteria developed by the Nuclear Construction Issues Group (NCIG-01, Rev. 1).
The TVA inspection identified the following discrepancies with the weld for the supports listed above:
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One fillet wcld low by 1/16 in, for more than 25% of length.
One weld made in the overhead position between two pieces of
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square tubing connected at an angle did not have the required fillet weld.
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Two intermittent welds were 2 in. long on 6 in. centers, but the drawing specified 2 in long.on 4 in. centers.
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The intermittent welds mentioned above were staggered in their placement, but the drawing specified that the welds should be side by side.
The intermittent weld symbol on the drawing was incorrect as
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it required a full penetration weld at a flare-bevel connec-tion.
The edge of one weld had surface slag of an excessive length.
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(6) Review of' Inspection Records The inspectors reviewed a sample of NDE reports for the following welds:
Group 2 - Items 1, 5, 7, 8, 9, and 16
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Group 3 - Items 3 and 6 The records were reviewed for general content and completeness.
(7)
Inspection Sample Distribution The inspectors reviewed the TVA inspection sample distribution for each category or group of welds as defined in paragraph 5.b.(1)
above. The following describes the distribution:
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No. of
Group Item Weld Type System Welds
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Pipe CBT
Pipe SEN
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Pipe EA 132
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Pipe AFD
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Pipe ERCW
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Group 1 Total 234 No. of Group Item Weld Type System Welds
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1 Pipe Support ERCW
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Pipe Support CC
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Pipe Support CC
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Pipe Support ERCW
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Pipe Support ERCW
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Pipe Support
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Pipe Support CC
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Pipe Support.
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Pipe Support CC
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Pipe Support-CVCS
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23 Pipe Support ERCW
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Pipe Support.
Aux. Boiler
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Pipe Support Aux. Boiler
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Pipe Support HVAC Chiller 43 Group 2. Total 459 No. of Group Item Weld Type System Welds
3 Conduit Support
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14 Cable Tray Support
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Group 3 Total 476
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No. of Group Item Weld Type System Welds
18 Pipe Rupture
Protection Barrier
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Structural Steel Deck-El 714
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Group 4 Total 122 i
No. of Group Item Weld Type System Welds
2 HVAC Support
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4 HVAC Support
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Group 5 Total 165 No. of Group Item Weld Type System Welds
30 Spiral Welded Duct
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Group 6 Total
~T5 The items within each group.iere rather evenly divided between Units 1 and 2.
In general, the items represented the entire time frame of construction and operations and as the major construction effort was in 1976-1978, the systems / structures reinspected reflected this.
As noted in the above table, the reinspection plan requirement to inspect 100 welds in each of the first five groups was well exceeded.
(8)
Inspection Results At the conclusion of the inspection, TVA had identified some problems with the welds they had inspected.
In general, the problems found with structural welds were slightly under-sized fillet welds.
In general, the problems found with piping welds were surface in nature.
At the conclusion of the inspection, TVA was still evaluating their inspection results to determine the significance of their. findings.
In addition, TVA found some welds in spiral welded air ducts that appeared to be welded less than 360 (see paragraph (4) above for a discussion of this problem).
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Review of Audit and-Inspection Personnel Qualifications
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(1) Bechtel Audit Personnel i
i Four auditors, one. lead auditor and a_NDE Level III examiner were responsible for performing the independent welding audit.
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inspectors reviewed the following records for these personnel:
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Auditors - Summary of Education and Experience History.
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- Letter Statement of Qualification as Auditors to
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ANSI /ASME'N45.2.23 and Regulatory Guide 1.146 Lead Auditor - Summary of Education and Experience History
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- Record of-Recertification as Audit Team
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Leader
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Level III Examiner - NDE Level III Certification Records-Including Eye Test and Summary of
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Education and Experience History
. Combined, the four auditors had 66 years of experience relative'to
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the area being audited. The auditor with the;1 east experience had i
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five years and the auditor with the most experience had 33 years experience.
The lead auditor had approximately 30-years of-
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related experience.
The level III examiner had 18 years NDE j
experience.
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Personal -interviews revealed that - audit personnel were very.
i knowledgeable in'the areas being audited.-
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_(2)- TVA Re-Inspection Personnel Qualifications
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For-the reinspection, TVA utilized four Certified Welding Inspec-j tors (CWIs) for structural welds and ten SNT-TC-1A level II hDE -
i examiners for pipe welds.
All inspectors ~ and examiners.were TVA
personnel.
In addition, Bechtel provided a CWI (for structural l
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welds) and a level III NDE examiner.(for pipe welds)Lto serve as independent overview personnel for this reinspection effort. -The
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NRC inspectors reviewed the following records for _the inspection
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personnel:
CWIs (four TVA and one' Bechtel) _
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AWS CWI Certification Records
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Evidence of VWAC (Visual Weld Acceptance Criteria)-
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TVA Level II Examiners (six examiners inspecting the pipe welds listed in paragraph b.(3) above)
Eye tests
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NDE Level II certification records including
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education and experience summary Bechtel NDE Level III Examiner Eye tests
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NDE Level II certification records including
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education and experience summary Records indicated that inspection personnel were very experienced in the NDE methods being used.
Personal interviews and observa-tion of inspections, revealed that inspection personnel were very knowledgeable in the NDE methods being applied.
d.
Review of the TVA Welding Project Program Description and Sequoyah
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Phase I Action Plan On January 23, 1986, the inspectors received a copy of the January 17,
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1986, TVA submittal relative to the TVA welding program.
The inspec-tors made a preliminary review of the following documents from the submittal:
Enclosure 1 - "TVA Welding Project Program Description"
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Enclosure 1, Attachment IA
" Welding Project - Phase I,
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Steps 1 and 2 - Nuclear Operations Work Plan" Enclosure 1, Attachment IB
" Welding Project - Phase I,
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Steps 1 and 2 - Office of Engineering Work Plan"
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Enclosure 1, Attachment IC
" Welding Project - Phase I, Steps 1 and 2 - Office of Construction Work Plan" Enclosure 2 - "TVA Action Plan - Welding Related Activities l
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SQN Units 1 and 2 Enclosure 2, Attachment I
" SON Determination of Service
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Suitability of Welds" In review of these documents, the inspectors noted that the terms
" adequate for service" and " meet all commitments" appear to be used interchangeable. The following are examples-
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Page 2, Enclosure 1
" Verify the weldmends made by TVA in the
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(6 lines from bottom)
field meet commitments and requirements or are adequate for service"
-- adequate to meet TVA commitments, Page 3, Enclosure 1
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code and regulatory requirements"
"Weldments - meet requirements or are Page 4, Enclosure 1
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adequate for service" Page 12, Enclosure 1 -
" Reinspection of TVA welds will be conducted to determine compliance with program commitments or suitability for service" Figure 2
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" Adequate to meet TVA Code and Regulatory requirements" The inspectors pointed out that these terms should not be used inter-changably but as two separate steps.
The first step should be to determine if commitments / requirements were met and the second step to determine adequacy for service.
TVA acknowledged the above comments.
Pending further review of the TVA submittals and inspection programs, this matter is identified as Inspector Followup Item 327, 328/86-09-03, Clarification of Terms " Adequate for Service" and " Meets All Require-ments" Relative to TVA Welding Program.
e.
Review of Aptech Study of Welding Quality Aptech Engineering Services reviewed the Sequoyah welding program to determine if the quality of welds at the plants were sufficient for their service.
At the time of the NRC inspection, the Aptech report had not been submitted to the NRC.
The inspectors made a preliminary review of the Aptech report (obtained at the site) and the accompanying TVA document.
The documents were identified as follows:
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AES 8511598AQ-1 Evaluation of Quality of Welds-at Sequoyah Nuclear Plant by Aptech Engineering Services, Inc., January 1986 Attachment 1 to Enclosure 2 to TVA's submittal dated January 17,
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1986 - SQN Determination of Service Suitability of Welds
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The Aptech Study involved three tasks _as follows:
The first task was to review the overall welding quality assurance
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program including a review of welding, construction, and inspec-i tion procedures, control of material and weld consumables, and qualification of welders and. inspectors.
In addition to the
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program review and as a check on implementation of the program, Aptech selected at random two welds for detailed examination of documentation supporting these welds.
In summary, Aptech found that the program contained the necessary checks and balances to ensure high quality welding.
The second task was to consider the preservice inspection (PSI)
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and inservice inspection (ISI) results as quality indicators and
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review these records and address the significance of the data on operational safety and derive conclusion regarding construction
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practices.
Aptech concluded that indication rates, based on ISI, provide greater confidence in the quality of the welds than the 95%
confidence /95% probability level common in the nuclear industry.
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The third task was to review the operational experience for indications of deficient weld quality as reflected in operation performance.
This review was based on a review of Licensee Event Reports (LERs).
Aptech concluded that no LERs have been generated which relate to poor welding.
Aptech noted the following:
that the quality of shop welds made by certified vendors has not
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been questioned and therefore, Aptech did not evaluate them.
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that TVA does not place requirements on the traceability of a heat number of a welding electrode to a particular joint.
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that in some cases, the acceptance criteria for welds was more lenient than the code of record, but technical justification existed for deviations.
Within the areas inspected, no violation or deviations were identified.
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