IR 05000275/1998017
| ML16342A641 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 01/06/1999 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML16342A640 | List: |
| References | |
| 50-275-98-17, 50-323-98-17, NUDOCS 9901130045 | |
| Download: ML16342A641 (26) | |
Text
ENCLOSURE U.S. NUCLEAR REGULATORYCOMMISSION
REGION IV
Docket Nos.:
License Nos.:
Report No.:
Licensee:
Facility:
Location:
Dates:
Inspectors:
50-275; 50-323 DPR-80; DPR-82 50-275/98-17; 50-323/98-1 7 Pacific Gas and Electric Company Diablo Canyon Nuclear Power Plant, Units 1 and 2 7 ~A miles NW of Avila Beach Avila Beach, California November 2-5 and December 7-11, 1998 L. E. Ellershaw, Senior Reactor Inspector, Engineering and Maintenance Branch Approved By:
C. A. Clark, Reactor Inspector, Engineering and Maintenance Branch Dr. Dale A. Powers, Chief, Engineering and Maintenance Branch Division of Reactor Safety Attachment:
Supplemental Information 990ii30045 990iQb PDR ADQCK 05000275
V
-2-EXECUTIVE
SUMMARY
Diablo Canyon Nuclear Power Plant, Units 1 and 2
NRC Inspection Report 50-275/98-17; 50-323/98-17 Maintenance The licensee's welding program and welding inspection procedures appropriately addressed inspection and monitoring requirements specified in ASME Code Sections III and IX, ANSI/ANS Codes B31.1 and B31.7, and Structural Welding Code AWS D.1-1.
The procedures provided clear guidance with respect to inspections, frequencies, and responsibilities (Section M3.1).
Welding material control requirements were being properly implemented by the weld room attendant who had a good understanding of the bases for those requirements (Section M3.2).
The inspectors concluded that record reviews indicated that licensee personnel were properly identifying, correcting, and documenting discrepant weld conditions, with subsequent notification being made to appropriate management (Section M7.1).
=REPORT
DETAILS=
'umma of Plant Status Unit 1 operated at 100 percent power, while Unit.2 varied between 50 percent and 100 percent power during the inspection period.
II. Maintenance
,. M3 Maintenance Procedures and Documentation M3.1 Weldin and Weldin Ins ection Procedures 55050 Ins ection Sco e
The scope of this inspection was to evaluate the licensee's welding and welding inspection program, which included the following implementing procedures:
~
"Nuclear Welding Control Manual," Revision 37 Procedure WI-1, "Visual Inspection of Welds," Revisions 5 and 6 Procedure WI-2, "Qualification and Certification of Welding inspectors,"
Revisions 3 and 4 Procedure GWS-ASME, "ASME General Welding Standard" Revisions 4 and 5 Procedure MA3.DC1, 'Weld Planning and Inspection," Revisions 3 and 4 Procedure GWS-AWS, "AWS Structural Steel General Welding Standard,"
Revision 4 Procedure QCP10.2, "Inspection Activities," Revisions 13 and 14 The inspectors did not observe any in-process welding during this inspection.
b.
Observations and Findin s At Diablo Canyon Nuclear Power Plant, inspection of quality or safety related welds is performed by inspectors from the nuclear quality services (NQS) organization.
Nonsafety-related welds may or may not be inspected.
This is left up to the discretion of the applicable welding engineer.
The various welding codes recognize that levels of inspection effort are commensurate with the quality level of the item being welded. The inspectors reviewed and discussed with NQS personnel the organizational structure and composition of NQS. The inspectors determined that significant changes to the structure and composition of NQS occurred twice in the past year.
Until April2, 1998,
the NQS inspectors (also commonly referred to as quality control inspectors), including welding inspectors, were part of the NQS maintenance/modifications inspections and monitoring group. On April 2, 1998, the NQS maintenance assessment group was combined with the NQS maintenance/modifications inspection and monitoring group.
The maintenance assessment supervisor was selected as the supervisor for the combined group and the new group was named the maintenance assessment and inspection group. On July 15, 1998, the maintenance assessment and inspection supervisor was subsequently selected for another position and a new supervisor was selected for the group.
In addition, the licensee recently initiated an "Asset Team" concept for performance of work. The July 15, 1998, NQS organizational chart designated the inspectors that would represent NQS on the asset teams.
The inspectors reviewed and evaluated welding inspection and monitoring requirements for certain parameters such as inspection of cleanliness and fit up, and monitoring of temperature and electrical characteristics.
The various welding codes addressed cleanliness requirements to some extent (e.g.,'urfaces for welding shall be clean and free from paint, oil, rust, scale, or other materials which may be detrimental to welding). Cleanliness inspection, however, was not similarly addressed in such definitive fashion.
The ASME Code addressed visual examination (other than nondestructive examination)being performed to verify compliance with cleanliness requirements, and that it may be performed by.the persons who perform or supervise the work. The ASME Code also stated that visual examination was required for tack welds that were to be incorporated into the final weld.
The ANSI/ANS B31.1 and B31.7 Codes state that visual examinations consist of observation of whatever portions of a component or weld are exposed to such observation, either before, during, or after manufacture, fabrication, assembly, or test.
Structural Welding Code AWS D.1-1 states that inspections and tests shall be performed, as necessary, prior to assembly, during assembly, during welding, and after welding to ensure that materials and workmanship meet the requirements of contract documents.
It further states that the inspector, at suitable intervals, shall observe joint preparation, assembly practice, welding techniques, and performance of each welder to make certain that the applicable requirements of the Code are met.
While the various welding Codes do not specifically address monitoring, it is implicitby the need to assure compliance with essential variables.
Structural Welding Code AWS D.1-1 requires inspection, as necessary, and inspection at suitable intervals, to make certain that applicable requirements are met. Where essential variables are involved, then it was incumbent upon the responsible organization to verify compliance.
The ASME Code specifically requires compliance with essential variables, with failure to do so making requalification of the welding procedure specifications mandatory.
The inspectors determined, based on review of welding procedure specifications (4 AWS and 17 ASME), the AWS and ASME General Welding Standards, and Procedure Wl-1 that the only welding-associated monitoring activities required of welders dealt with preheat and interpass temperatures, and heat input. The tools used for monitoring these parameters were thermocouples, temperature indicating crayons, or contact pyrometers.
Typically, welders use temperature indicating crayons.
Allother verification/inspection activity associated with welding was required to be performed by certified inspection personnel.
In fact, one of the specified inspection verification activities was to verify that the welder had the necessary temperature measuring tools for monitoring the above parameters.
Much of the welding Code discussion is based on the fact that welding is to be conducted by qualified welders, and that qualified welders would have been trained sufficiently to have an understanding of the need for cleanliness requirements and the impact of not having clean surfaces.
I The following procedures were established by the licensee to identify and implement the above welding code requirements.
Procedure WI-1, Revision 6, paragraph 2.0, provided clear and concise guidance with respect to welding inspection in terms of frequency, type and extent, and documentation.
Procedure WI-1, paragraph 6.4 required weld joints to be properly prepared and cleaned in accordance with the applicable General Welding Standard.
It further provided guidance with respect to when the weld joint preparation and cleanliness inspection could occur. For example, inspection of weld joint preparation and cleanliness can be performed either prior to assembly or after tack welding at the time of fitup inspection.
The paragraph included cleanliness inspection and acceptance guidance for single-sided butt welds, structural components, and socket joints, all of which met the current requirements of either the ASME or AWS Codes.
In addition, the paragraph allowed the weld inspector to require that a joint be disassembled for further inspection if there was reason to believe that the weld joint was not properly prepared and cleaned.
Paragraph 6.6 required verification that tack welds were removed, or that they were sound and properly prepared for incorporation into the final weld. It also included provisions for verification that the engagement of socket welds was in
'accordance with the ASME General Welding Standard.
Procedure GWS-AWS, Paragraph 2.5, stated that the weld preparation and base material surfaces for a distance of 1-inch from the weld preparation shall be cleaned and kept free of oil, grease, dirt, scale, and other foreign materials.
Paragraph 4.4 stated that tack welds shall be made in full compliance with this welding standard and, if not removed, their stopping and starting ends shall be properly prepared by grinding or other suitable means for satisfactory incorporation into the final weld. Tack welds becoming part of the finished weld shall be visually examined, and defective tack welds removed.
~
Procedure GWS-ASME, paragraph 2.2, stated that the weld preparation and base material surfaces shall be cleaned and kept free of oil, grease, dirt, scale, and other foreign materials for a distance of 1 inch from the weld preparation for ferrous materials and 2 inches for nonferrous materials.
At areas where elemental sulfur contamination can occur, the weld preparation and all areas within 3 inches of the weld shall be cleaned using acetone.
Paragraph 4.5 stated that tack welds shall be made in full compliance with this welding standard and, if not removed, their stopping and starting ends shall be properly prepared by grinding or other suitable means for satisfactory incorporation into the final'eld.
Tack welds becoming part of the finished weld shall be visually examined.
c. Conclusions
The program/procedures review revealed that the requirements of ASME Code Sections illand IX, ANSl/ANS Codes B31.1 and B31.7, and Structural Welding Code AWS D.1-1 (pertaining to inspection and monitoring) were appropriately addressed.
The licensee's procedures provided cfear guidance with respect to inspections, frequencies, and responsibilities.
M3.2 Wefdin Material Stora e 55050 The inspection scope was to evaluate the licensee's welding material storage facilities and to verify that welding material was appropriately stored and controlled.
b.
Observations and Findin s The inspectors reviewed implementing Procedure FMC-1, "FillerMetal Storage and Handling," Revision 2, and verified that the weld room attendant maintained a current copy.
The inspectors toured the welding material storage and issue room. Allholding ovens were appropriately identified and maintained at the proper temperature range.
The inspectors verified that the weld rods inside each oven corresponded to the weld rod identification noted on the ovens, and that the material was traceable to the applicable certified material test reports. A rebake oven was being used for returned weld rod that had exceeded the specified issue time limits. Controls had been established to limitthe number of rebakes, and the oven temperature had been set in accordance with ASME Code requirements.
The weld room attendant had a good understanding of welding material storage and handling requirements.
c. Conclusions
Welding material control requirements were being properly implemented by the weld room attendant who had a good understanding of the bases for those requirements.
M7 Quality Assurance in Maintenance Activities M7.1 Wefdin Trend Anal sis 55050 a.
Ins ection Sco e
The inspectors reviewed and evaluated the methodology used by the licensee for documenting and correcting welds that were identified as being discrepant.
This included a review of the following procedures.
Procedure OM7.ID10, "Quality Trend Analysis Program," Revision 6 Procedure OM7.ID1, "Problem Identification and Resolution-Action Requests,"
Revision 9 b;
Observations and Findin s Procedure OM7.ID10 governed the use of event trending records (ETRs). The procedure defined an ETR as a document that was used to capture data about a
~
condition, event, or issue.
It was required for all quality problems (identified on an action request) and was recommended for certain nonquality problems and certain nonproblems (the reason being that nonquality problems or nonproblems could help identify precursors to more significant quality problem events).
The procedure. also required that the'data be analyzed to identify and evaluate quality performance trends, and to report these trends to management.
Paragraph 2.2 referenced Appendix 7.2 in Procedure OM7.ID1 for guidance on when an ETR should be created for nonquality problems and for events which do not have to be documented on an action request.
Appendix 7.2 specifically identified the following condition in which an ETR should be generated:
rejectable work identified and corrected before final NQS acceptance of the work, provided the disposition of the condition is documented in the inspection or assessment report, or process control sheet, as applicable.
During the week of November 2, 1998, the inspectors requested an electronic listing showing all welding-related ETRs issued since March 1997. The listing provided by licensee personnel identified 173 welding-related ETRs. The inspectors reviewed the electronic descriptions and identified 36 ETRs that appeared to be related specifically to discrepant welds. The inspectors then reviewed the 36 ETRs and determined that 26 actually dealt with rejectabte weld conditions.
Allof the ETRs stated that "No Action Request" was required in accordance with Procedure OM7.ID1." This determination was in accordance with Procedure OM7.ID1 that stated an action request was not required if the rejectable condition was identified and corrected before final NQS acceptance of the weld, and if the disposition of the condition was documented.
The inspectors reviewed the applicable work order packages associated with the sampled ETRs and determined that, with the exception of two, each work order either referenced the applicable ETR'or had a notation that brieflyaddressed the reason for the ETR and the actions taken to resolve it. Licensee personnel informed the inspectors that a scheduled NQS self-assessment was in-process, and that the subject of condition dispositions not being documented in the applicable work order packages would be added to the self-assessment scope.
During the week of December 7, 1998, licensee personnel informed the inspectors that the NQS self-assessment identified an additional 18 ETRs, which addressed rejectable conditions in which the information had not been captured in the work order package documentation.
NQS personnel initiated Action Request AO472547 on December 4, 1998, to document the failure to record or reference ETR conditions in the applicable work orders. The due date for completion of the evaluation and associated corrective actions was established as the end of February 1999. Licensee personnel verified and were able to demonstrate to the inspectors that, in each case, the rejectable condition.
that caused the ETR to be initiated in the first place had been corrected, and that this appeared to be only a documentation issue.
As such, the inspectors determined that the documentation issue had no safety impact. This failure constitutes a violation of minor significance and is not subject to formal enforcement action.
Paragraph 5.7 in Procedure OM7.ID10 required NQS to perform periodic and systematic reviews and evaluations of ETR data to identify trends adverse to quality and repetitive occurrences of undesirable events.
The procedure provided sufficient guidance to accomplish that task. The procedure further required the results of the evaluations to be incorporated into a quality performance assessment report. Paragraph 5.9 required NQS to provide a copy of the quality performance assessment report (at least three times a year) to the following: senior vice president and general manager, nuclear power generation; nuclear safety oversight committee; plant staff review committee, and the management of the affected organizations.
The inspectors reviewed one NQS evaluation report pertaining specifically to maintenance inspection and monitoring, dated March 26, 1998. This report analyzed data acquired from ETRs and action requests during Refueling Outage 2R8 (February and March 1998). The inspectors observed that evaluations had been performed on ETRs that addressed rejected welds. The evaluations determined that these were isolated instances and that no trends were identified from the inspection process that would impact the quality of safety-related work. The inspectors also reviewed a quarterly ETR data analysis report, "3Q98 ETR Data Analysis," that was very comprehensive, and addressed ETRs pertaining to maintenance and operations activities.
In addition, the inspectors reviewed seven quality performance assessment
'eports (four from 1997 and three from 1998) and determined that weld reject information had been properly identified and evaluated.
No adverse trends were identified by the licensee's evaluation process.
The inspectors determined that discrepant welds had been identified on ETRs.
It is important to remember that inspection is considered in-process until the time that the welding inspector performs and accepts the final inspection.
Therefore, if a weld has a discrepant condition identified prior to final inspection acceptance, rework is allowed to make the weld acceptable.
Rework, as defined by ANSI N45.2.10-1 973, is the process by which a nonconforming item is made to conform to a prior specified requirement by completion, remachining, reassembling or other corrective means.
This is opposed to repair, which is defined as the process of restoring a nonconforming characteristic to a condition such that the capability of an item to function reliably and safely is unimpaired.
Conclusions The inspectors concluded that licensee personnel were properly identifying, correcting, and documenting discrepant weld conditions, with subsequent notification being made to appropriate management.
uali of Weldin Related Work Orders 55050
~Sca e
To determine the quality of the licensee's overall planning and scheduling of welding activities, the inspectors evaluated the initiation and implementation of welding related work orders.
The inspectors reviewed the following applicable procedures:
MA3.DC1, 'Weld Planning and Inspection," Revision 4 AD7.ID1, "Use of PIMS Work Order Module," Revision 2 AD7.DC8, "Work Control," Revision 0 and Observations and Findin s During review of the electronic listing of ETRs, the inspectors noted that several pertained to the overall quality of work orders.
It appeared that the problems typically revolved around the need to revise work order information such as inspection planning.
During review of the above procedures, the inspectors learned that Procedure AD7.ID1 was designed to protect the work order activity description following entry of NQS review and date in the quality control plan review field. This protection was designed to prevent any subsequent and unauthorized changes to the work order.
If additional work order processing was required, NQS had to electronically "unlock" the work order by deleting the NQS reviewer's name and date from the quality control plan review field. Following any changes, the work order had to be returned to NQS for review and subsequent electronic "lockup." The inspectors learned that ETRs were generated each time a work order was electronically unlocked, regardless of the reason.
This appeared to have been an overly conservative approach that caused generation of a large number of ETRs. Nearly all changes were caused by creation of work orders as much as 12 weeks in advance of the actual work to be performed.
This practice did not allow routine changes to work orders (i.e., revisions to procedures, materials, schedule, etc.) without "unlocking" the work order and initiation of an ETR.
Since ETRs were being analyzed and trended, it became apparent to licensee personnel that they were being penalized by the large number of ETRs issued as a result of their trying to preclude unauthorized changes to work orders.
Procedure ADT.ID1 was rescinded and replaced by Procedure ADT.DC8, which defers NQS review and signoff until just prior to the work order being issued for implementation.
This allowed controlled changes to be made to work orders without requiring NQS review and approval following each change.
The number of ETRs initiated for work order changes was subsequently reduced significantly.
The inspectors did not identify any instances of welding related work orders exhibiting poor quality as a result of inadequate planning, preparation, or personnel not being cognizant of requirements.
C.
Conclusions The inspectors determined that licensee personnel created unnecessary work requirements for themselves by issuing large numbers of ETRs for activities that would otherwise have been considered normal and routine. Based on review of welding related work orders and ETRs, the inspectors concluded that the overall quality of the licensee's planning and scheduling of welding activities was good.
V. Mana ementMeetin s
X1
Exit Meeting Summary
The inspectors presented the inspection results to members of licensee management on December 10, 1998. The licensee personnel acknowledged the findings presented.
The onsite inspection continued, however, until December 11, 1998.
The irispectors asked the licensee personnel whether any materials examined during the inspection should be considered proprietary.
No proprietary information was identified.
ATTACHMENT
SUPPLEMENTAL INFORMATION
PARTIALLIST OF PERSONS CONTACTED
Licensee
- J. Anastasio, Engineer, Engineering Services
Engineer, Nuclear Safety Assessments
and Licensing
- G. Gurley, Engineer, Engineering Services
- N. Jahangir, Senior Engineer, Engineering Services
- H. Kamer, Auditor, Nuclear Quality Services
- S. Ketefsen, Supervisor, Nuclear Safety Assessments
and Licensing
- J. Portney, Senior Engineer, Engineering Services
- J. Prange, Asset Team Leader, Maintenance Support
- J. Sopp, Assistant to the Director, Maintenance Services
- D. Taggart, Director, Nuclear Quality Services
NRC
- D. Acker, Resident Inspector
INSPECTION PROCEDURES USED
Nuclear Welding General Inspection Procedure
DOCUMENTS REVIEWED
Procedures
Procedure WI-1, "Visual Inspection of Welds," Revisions 5 and 6
Procedure WI-2, "Qualification and Certification of Welding Inspectors," Revisions 3 and 4
Procedure GWS-ASME, "ASME General Welding Standard" Revisions 4 and 5
Procedure MA3.DC1, 'Weld Planning and Inspection," Revisions 3 and 4
Procedure GWS-AWS, "AWS Structural Steel General Welding Standard," Revision 4, dated
October 5, 1996
Procedure QCP10.2, "Inspection Activities," Revisions 13 and 14
Procedure FMC-1, "Filler Metal Storage and Handling," Revision 2
Procedure OM7.ID10, "Quality Trend Analysis Program," Revision 6
Procedure OM7.ID1, "Problem Identification and Resolution-Action Requests,"Revision
-2-
MA3.DC1, "Weld Planning and Inspection," Revision 4
AD7.ID1, "Use of PIMS Work Order Module," Revision 2
AD7.DC8, "Work Control," Revisions 0 and
Other Documents
Nuclear Welding Control Manual, Revisions 34 through 37
AO430549; April28, 1997
AO431 726, May 5, 1997
AO437820, June 20, 1997
AO442680, August 28, 1997
AO443408, September 9, 1997
AO444892, October 2, 1997
AO445679, October 14, 1997
AO446513, October 28, 1997
AO446650, October 29, 1997
AO450073, December 30, 1997
AO451162, January 16, 1998
AO451576, January 23, 1998
AO452231, February 3, 1998
AO452413, February 4, 1998
AO453059, February 12, 1998
AO454730, February 27, 1998
AO456224, March 10, 1998
AO456474, March 12, 1998
AO459878, April'15, 1998
AO462295, May 27, 1998
AO462704, June 4, 1998
AO464101, July 2, 1998
AO464459, July 8, 1998
AO466159, August 7, 1998
AO469978, October 15, 1998
Events Trend Anal sis
VOOO7888, May 5, 1997
VOOO8114, May 10, 1997
VOOO9525, August 20, 1997
VOOO9910, September
19, 1997
VOO10613, November 7, 1997
VOO11590, January 16, 1998
VOO11677, January 23, 1998
VOO13170, March 26, 1998
VOO14261, July 2, 1998
VOO14311, July 15, 1998
VOO1 4482, July 31, 1998
VOO1541 9, October 21, 1998
VOO15549, November 4, 1998
Work Orders
CO1 52667-03
CO155625-02
CO155716-01
CO157170-01
CO1 57757-01
CO157817-02
CO1 58507;01