ML20010G237
| ML20010G237 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 07/23/1981 |
| From: | Oprea G HOUSTON LIGHTING & POWER CO. |
| To: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| Shared Package | |
| ML20010G229 | List: |
| References | |
| ST-HL-AE-705, NUDOCS 8109150468 | |
| Download: ML20010G237 (22) | |
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The Light comPuy i e.,,em 1.,x,,mx & i.e.<,
s i:o.isexiroo iiee,,emzi<x,,,ooi ivi3>228 22ii July 23, 1981 ST-HL-AE-705 SFN:
V-0100 Mr. Karl Seyfrit Director, Region IV Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76012
Dear Mr. Seyfrit:
South Texas Project Units 1 & 2 Docket Nos. STN 50-498, STN 50-499 Revisions to Final Welding Report On May 1, 1981, HL&P submitted to your office the " Final Report of the Review of Safety-Related Welding at South Texas Project Electric Generating Station." During preparation sessions for the ASLB Hearing, the Task Force who had prepared the May 1 report came to the belief that certain revisions should be made that address previous findings in a more direct manner. The revisions explicitly state the problems discovered with five (5) welding procedures that had been written concerning welding of impact tested base material.
Note that these welding procedures have not been used during the restart activities covered under the previous Work Plans nor under the current Work Plan approved by your office July 10, 1981.
I Please insert the attached revised pages into your copies of report.
Very truly yours,
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Exec ive Nce President JGW/amj Attachment 8109150468 810821 DR ADOCK 05000 d
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O ilouston Lighting & Power Company ct:
J. H. Goldberg July 23, 1981 J. G. Dewease ST-HL-AE-705 D. G. Barker SFN:
V-0100 C. G. Robertson Page 2 Howard Pyle R. L. Waldrop H. R. Dean D. R. Beet'1 J. D. Parsons J. W. Williams J. W. Briskin J. E. Geiger STP RMS H. S. Phillips (NRC)
J. O. Read (Read-Poland,Inc.)
M. D. Schwarz (Baker & Botts)
R. Gordon Gooch (Baker & Botts)
J. R. Newman (Lowenstein, Newman, Reis, & Axelrad)
Director, Office of Inspection & Enforcement Nuclear Regulatory Commission Washington, D. C. 20555 R. L. Range /G. W. Muench Charles Bechhoefer, Esquire Central Power & Light Company Chairman, Atomic Safety & Licensing Board P. O. Box 2121 U. S. Nuclear Regulatory Commission Corpus Christi, Texas 78403 Washington, D. C.
20555 R. L. Hancock/T. H. Muehlenbeck Dr. James C. Lamb, III City of Austin 313 Woodhaven Road P. O. Box 1088 Chapel Hill, North Carolina 27514 Austin, Texas 78767 J. B. Poston/A. vonRosenberg Mr. Ernest E. Hill City Public Service Board Lawrence Livermore Laboratory P. O. Box 1771 University of California San Antonio, Texas 78296 P. O. Box 808, L-123
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Livermore, California 94550 Brian E. Berwick, Esquire William S. Jordan, III Assistant Attorney for the State of Texas Harmon & Weiss l
P. O. Box 12548 1725 1 Street, N. W.
Capitol Station Suite 506 Austin, Texas 78711 Washington, D. C.
20006 Lanny Sinkin Citizens for Equitable Utilities, Inc.
Citizens Concerned About Nuclear Power c/o Ms. Peggy Buchorn 5106' Casa Oro Route 1, Box 1684 San Antonio, Texas 78233 Brazoria, Texas 77422 Jay Gutierrez, Esquire Hearing Attorney Office of the Executive Legal Director U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Revision Date 7-22-81
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Revisions to Review of Safety-Related Welding at South Texas Project Electric Generating Station, April 1981
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Revisions were made to the following pages of the final report,
" Review of Safety-Related Welding at South Texas Project Electric Generating Station".
The revisions are provided in the attached pages.
1.
Page vi, paragraph one 2.
Page vii, paragraphs two and three 3.
Pages 2-39, through 2-41 revised in entirety 4.
Page 3-19, Section 3.4.3, paragraph one 5.
Page 3-20, Section 3.4.4, paragraph two 6.
Page 3-20, Section 3.4.5, paragraph one 7.
Page 3-21, Section 3.4.6, paragraph two 8.
Page 3-22, Section 3.5.3, paragraph one 9.
Page 3-24, Section 3.5.4, paragraph one G
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Revision 1
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C'nstruction procedures, and weld documentation for ASME piping o
were reviewed and found to be substantially in compliance with the Code, although a number of minor noncompliances were
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disclosed.~ With the exception of five welding procedure specifications (WPS), all WPSs were found to be substantially in compliance with the Code, although a number of minor f
i discrepancies were found.
These five WPSs were not properly
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written or c"alified to ensure compliance with the Code j
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requirements for welding impact tested base material.
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All weld filler materials for both safety-related piping and l
f structural welding were found to have been purchased from project-approved vendors and were traceable to the purchase documents and a Certified Material Test Report (CMTR).
A review of the CMTR's disclosed that the materials complied with the Code.
There was one instance of a minor noncompliance with an NRC Regulatory Guide regarding delta ferrite measurement.
A potentially significant noncompliance was disclosed in the radiographic evaluation of a number of welder qualification 1
tests.
Placement of the penetrameter on the film-side rather than the source-side could have resulted in a decrease in the ability to detect small discontinuities to a level below that required by the Code.
Other than this, the qualification of ASME welders was in compliance with the Code.
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Reexamination by VT and PT of twelve of the 26 accessible Essential Cooling Water System welds revealed only arc strikes, veld spa.tter and four liquid penetrant indications.
The PT
-y indications are believed to be nonrelevant.
The Code requires that nonrelevant indications be removed so that they do not mask relevant indications.
I Safety-related Structural Welds l
A random sample of 79 welds were visually reexamined and were found to contain a significant number of noncompliances with the l
American Welding Society's Dl.1, " Structural Welding Code".
These noncompliances ranged from weld spatter to undersize welds.
No cracks were found.
The construction procedures were found to contain a number of minor noncompliances and three that were considered significant enough to question the adequacy of some of the inspections.
Two noncompliances pertained to the frequency of inspection, and the other pertained to additional inspection requirements applicable if cracks were discovered during visual examination.
E AWS welding procedure specifications were found to be substantially in compliance with the Code, although a number of minor noncompliances were disclosed.
Two potentially significant noncompliances were also discovered regarding heat-affected zone o
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cooling rates but these were judged unlikely to have any effect on the integrity of the welds.
t The stru t ral weld documentation was found to be deficient because in many instances it was not possible to trace an inspection report back to the weld for which it was written.
The review of welder qualifications revealed that ASKE radio-graphic acceptance criteria had been used to evaluate some AWS welder qualification tests.
Both codes have similar, but not I
identical acceptance criteria.
This noncompliance was judged to l
have no effect on the weld quality.
I It was not possible to verify through documentation that the structural welders were qualified for ecch weld that they made because the documentation system did not require that each welder be identified.
However, a system was established which required that three individuals, the weld supervisor, the QC inspector and the weld technician who issued filler material verify welder qualification.
Review of the PSAR and FSAR revealed inconsistencies in the specified edition of AWS Dl.1 for structural welding.
Other similar inceasistencies were disclosed when the Engineering Specifications were compared with the implementing construction procedure.
However, these inconsistencies were not judged to l
have affected the quality of the welding.
viii Revision 1
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Fourteen audit reports were reviewed, but from the records it was not possible to determine their thoroughness.
It was disclosed thatwritInauditplanshadnotbeenusedaswasrequired.
Nonconformance Reports, Corrective Action Reports and Field Requests for Engineering Action were reviewed, but not in sufficient detail to provide meaningful results.
As a result of the Task Force findings, HL&P and Brown and Root have undertaken a comprehensive reexamination and repair program.
All accessible ASME Section III pipe and pipe hanger welds will be reexamined by the original nondestructive examination method, visual, liquid penetrant or both.
All deficiencies identified in this reexamination will be repaired.
In addition, all radiographic discrepancies identified by the Task Force will also be repaired and brought into Code compliance.
The Essential Cooling Water System (ECW) will be unearthed and all welds will be reradiographed except those welds which had previously been entirely radiographed and accepted by the Task Force.
All of the ECW system welds will also be reexamined visually and by liquid penetrant.
All deficiencies identified in this reexamination will be repaired.
2.11 ASME welds which are now inaccessible because of subsequent construction activities will be analyzed for acceptability.
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All ac'cessible safety-related structural steel welds will be visually reexamined and repaired.
All of the reexaminations and repairs will be perforr.ed by requalified and recertified
.q inspectors'.and welders.
Welds which are now inaccessible for reexamination and repair because of subsequen', construction l
activities will be analyzed for acceptability.
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Revision 1
2.'6 REVIEW OF ASME WELDING PROCEDURE SPECIFICATIONS 2.6.1 Scope
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The scope of this task was to review all current and past revi-sions to the ASME Section III welding procedure specifications (WPS) for compliance with the Code.
2.6.2
,.4e thod Tine ASME WPSs were reviewed for compliance with the requirements of ASME Section III. 1974 Edition with Addenda through Winter 1975, and the latest edition of ASME Section IX, " Welding and Brazing Qualification" in effect at the time of first issue of the WPS.
2.6.3 Results Current and past revisions of the WPSs were reviewed and all but five were found to provide the ussential information, when used in conjunction with the MECP-4, " Field Fabrication and Welding of Piping Systems and Components Supports - Nuclear Systems", to make welds in accordance with the Code.
However, many WPSc and Procedure Qualification Records (PQR) were found not to be in full compliance with the Code because of the omission of some of the detailed information required to be stated or recorded.
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general, these procedures lacked sufficient attention to the detailed Code requirements.
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_. g The five_WPSs which were not found to meet the requirements of the Code are listed below.
An explanation of these major discrepancies and certain of the minor discrepancies is provided in the discussion.
l WPS Discrepancy I
i 2017 Rev. O Not qualified for the spacified materials or processes is used on impact tested base materials.
- Also, there is insufficient information on the WPS to ensure compliance with I
the Code-required limitation on the maximum heat input for impact tested base material.
2018 Revs. 0,1,2,3 Insufficient information on the WPS 2025 Rev. O, 2032 Rev. O to ensure compliance with the Code-required limitation on the maximum heat input for impact tested base material.
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2036 Revs. 0,1 Not qualified for the combination of processes if used on impact tested base material.
Also there is insufficient information on the WPS to ensure compliance with the Code required limitations on the maximum heat input for impact tested base material.
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2.6.4 Discussion An expla. nation of the major deficiencies is provided below:
-g Maximum Heat Input When a WPS is qualified for use on impact l
tested base materials, the Code requires that the heat input used in production welding be limited to the maximum heat input used in qualification of the WPS.
For the four WPSs in question -
2017, 2018, 2025, and 2036 - the information required to calculate maximum heat input was recorded on the PQR, but was not properly stated on the WPS.
It is therefore possible that the l
maximum heat input qualified may have been exceeded during production welding.
If this did occur, it is possible that the impact properties of the case metal heat-affected zone or weld metal may have been degraded.
WPS 2017 Rev. O The Code requires that base material be qualified by P-number and Group number when the WPS is used on impact tegted base material.
This WPS specified P-No. 1, Group 1 and 2 base materials but the qualification was performed only on Group 1 materials.
Also the WPS is for a daal-process weld, that is both gas tungsten arc (GTAW) and shielded metal arc (SMAW) processes would be used to make the weld.
The impact tests were made only on a coupon welded with the SMAW process.
The WPS is therefore uhqualified for making welds with the combination of u
processes in base materials which require impact testing.
It is lO 2-41 Revision 1
only qualified for the combination of processes in the listed materials for thickness between 0.063 in, and 0.560 in. which do not require impact testing.
g Since the'WPS was unqualified for impact tested material, it is possible that the weld metal and heat-affected zone impact properties of welds made in accordance with to this procedure may have been degraded.
WPS 2036 Rev. 0,1 This WPS has the same deficiencies as WPS 2017, except that the materials used in the qualification were l
Correct.
WPS 2032 Rev. O The oscillation frequency and dwell time were not stated on the WPS, and the minimum travel speed stated on the WPS was less than that qualified on the PQR.
Both of these deficiencies could have adversely affected the weld metal and l
base metal heat affected zone impact properties.
An explanation of the minor WPS deficiencies is provided below:
Oscillation Parameters for GTAW In the Edition and Addenda of the Code used to qualify the WPSs, there is a requirement to specify the oscillation width, frequency and dwell time for the GTAW process.
For all but one of the WPSs which did not provide this information, the WPSs were either not used on production 2-41a Revision 1
w'ldments, or the information was a non-essential variable.
The e
exception, WPS 2032, Rev. O, has been discussed previously.
Maximum Be Thickness The Code requires that if the bead thickness is > 0.5 in., the qualification is valid only for thicknesses up to 1.1 times the thickness of the qualification coupon, instead of the normal 2 times coupon thickness.
No statement appeared on a number of WPSs limiting weld pass thickness to j( 0.5 in.
This was not judged to be a significient deficiency because it is unlikely that this bead thickness was exceeded for the weld processes qualified.
Deletion of Consumable Insert One WPS was improperly qualified because a consumable insert was not used in one of the two qualification coupons.
This was not judged to be a significant deficiency becasue the WPS was used only for welder qualification and not for production welding.
All Position Qualification Most of the impact tested WPSs were qualified in the 6G pipe position.
The statement made on the WPS was that this qualified for all positions.
The Code states that only the 3G plate position, upward progression qualifies for all position welding.
This was not judged to be a significant d'eficiency because an official ASME Code interpretation by the ASME Main Committee, IX-78-64, April 4, 1978, allows the SG pipe position to qualify for all other positions.
After further 2-41b Revision 1
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l discussion with a member of the ASME Subcommittee On Welding (SCIX), it was concluded that the 6G position, which is similar to the SG position, would qualify for all positions.
To confirm
.. g this, an -official interpretation from the ASME Code Main Committee should be made.
Code Case Qualification Two WPSs were qualified in accordance with ASME Code Case N-71-7 which puts additional restrictions on welding procedure qualification requirements.
The WPSs did not j
meet all of these h3ditional requirements.
This was not judged to be a significant deficiency because a later revision to this Code Case eliminated these additional restrictions.
The WPSs met the requirement of the Code Case revision.
Peening Many of the WPSs lacked a statement on peening.
This was not judged to be a significant deficiency because it is a non-essential variable and the required statement was made in the piping construction procedure, MECP-4, which is used in conjunction with the WPS.
2.6.5 Conclusion Significant Code discrepancies were found in five WPSs which could have been used to weld impact tested base material.
A number of miner discrepancies were also found which were not believed to have any detrimental effect on the production welds, 2-41c
but indicate that more attention to the detailed Code requirements is required.
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-Recommendations The discrepancies in the WPSs should be corrected before they are used for future work.
WPSs written and qualified in the future should be carefully reviewed to ensure full Code compliance.
Additional qualification testing is recommended for those five WPSs with significant deficiencies in order to verify that any welds previously made with these procedures met the Code impact requirements in the weld metal and base metal heat affected Zone.
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3.4 REVIEW OF STRUCTURAL STEEL CONSTRUCTION PROCEDURES 3.4.1
. Scope l
Tne scope of this task was to review the structural steel l
construction procedures related to welding for compliance with the AWS Dl.1 " Structural Welding Code",1975 Edition.
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3.4.2 Method l
The following construction procedures have been reviewed:
PROCEDURE CODE OF RECORD A040KPCCP-15, Fabrication of AWS Dl.l(1975)
Miscellaneous and Structural Steel A040KPMECP-2, Fabrication and AWS Dl.l(1975)
Erection of Structural Steel to the Requirements of AWS Dl.1 A040KSWES-1, Stud Welding AWS D1.1(1975)
The original intent of the review was only to identify inconsis-tencies between the procedures and the applicable Code.
As the l
review continued, it was decided to include comments which, when 3-18 1
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incorporated into the procedures, would make the procedure more complete or more clear.
Therefore, not all of the comments included here represent inconsistencies with the Code.
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additione some of the Code comments are more significant than others.
Comments which were judged by the Review Team to represent inconsistencies with the Code if implemented as-written are identified by an asterisk.
These comments are addressed further in the discussion.
i 3.4.3 Results Appendix F contains the detailed comments on the construction procedures.
Of the comments made, th ee were considered c
significant.
In three of the earlier revisions to MECP-2, the frequency of visual examinations is specified to be at least twice per week.
AWS Dl.1 requires visual examination of every weld.
i AWS Dl.1 also requires that when cracks are found by visual examination, the extent of cracking be determined by magnetic particle testing or other equally positive means and that the crack and sound metal for 2 inches beyond both ends of the crack be removed before welding.
These requirements were not addressed in MECP-2.
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WES-1, the stud welding procedure, did not adequately identify I
all the stud welds which must be bend tested.
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3.4.4
-Discussion The comments made in Appendix F which are identified with an asterisk represent inconsistencies with AWS Dl.1 (1975).
All of the Code inconsistencies did not, in the judgment of the Review Team, permit violations to the Code which could jeopardize the integrity of the welds made in accordance with the procedure.
There were, however, three inconsistencies which were judged to be significant.
These are discussed below.
A040KPMECP-2, Comment 3.
In three of the earlier revisions to this procedure, the frequency of final visual inspections was specified as at least twice per week.
This statement is clearly not in accordance with the Code, which requires that all of the welds be examined visually.
This inconsistency may have, in part, contributed to the poor quality of visual examination reported in Section 3.1.
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A040KPMECP-2, Comment 17.
The procedure did not specify the Code requirement that the extent of weld or base metal cracking be defined by some positive means like magnetic particle testing and that two inches of sound metal on either side of the crack be
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removed before welding.
The omission of these requirements in 3-20 fhwitaka 51 1
MECP-2 would not have caused a crack to go undetected since this requirement is applicable only after a crack has been detected.
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A0=CKSWES-1, Comments 5, 7, 9, 11, 14.
All of these comments are concerned with the proper identification of welds which must receive additional bend testing to insure they meet the soundness criteria.
In the judgment of the Review Team, failure to address some of the Code inspection requirements for stud welding could have resulted in some substandard welds being accepted.
3.4.5 Conclusion The review of the procedures has disclosed three violations to AWS Dl.1 which were judged significant enough to warrant an investigation into the acceptability for service of those welds inspected in accordance with the procedures.
The violations pertained to the frequency or extent of weld inspections and the additional inspection requirements if cracks are found.
None of the violations would have caused substandard welds to be made, but may have allowed substandard welds to have been accepted.
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3.4.6 Recommendations The three construction procedures should be revised to 6
incorporitE'the Task Force comments.
Future revisions to the procedure should be carefully reviewed by Brown and Root to ensure Code compliance.
It should be verified by Brown and Root that the welds made in accordance with the two noncomplying procedures received adequate examinations.
The recommendations to reexamine all accessible welds and to analyze the inaccessible welcs made in Section 3.1.6, if adopted, would provide such verification.
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l 3.5 REVIEW OF AWS WELDING PROCEDURE SPECIFICATIONS 3.5.1 Scope i
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The scope of this task was to review all current and past revi-sions to the AWS Dl.1 welding procedure specifications WPS for compliance with the Code.
3.5.2 Method l
The AWS D1.1 WPSs were reviewed for compliance with the requirements of AWS Dl.1 " Structural Welding Code", 1975 Edition.
3.5.3 Results Forty-two AWS welding procedure specifications were reviewed.
These included procedures which the Code considered prequalified, t
l that is, not requiring qualification testing, and those for which qualification testing was required.
Discrepancies with one or more of the Code details were found in many of the WPSs, indicating that adequate attention to the Code details was not given, particularly in the early revisions of the procedures.
In later revisions, the quality of the procedures improved.
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In several procedures, the amperage and voltage ranges were not shown for all electrode sizes.
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Iii'several prequalified procedures, the Code conditions for prequalification were not entirely met.
3.5.4 Discussion In writing a prequalified WPS or in writing and qualifying a WPS, a large amount of information is required to be specified and compliance with a number of detailed rules is required.
Most of the WPSs reviewed did not fully comply with all the Cose require-ments, indicating a iack of attention to detail or a lack of understanding of the Code requirements.
These discrepancies were judged not to have any significant effect on the integrity of the welds.
Two discrepancies (numbers 1 and 2) were identified which had the potential to increase the chance of cracking in the base metal.
Both of these requirements, preheat and weld size, were properly addressed in MECP-2, the construction procedure for structural steel which is required to be used in conjunction with the WPSs.
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