ML20199L672

Insp Rept 99900912/98-01 on 980106-08.No Violation or Deviations Noted.Major Areas Inspected:Assessed Specific Attributes & Implementation of 10CFR50,App B & QA Program as Applied to Procurement Mod

ML20199L672
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Issue date:	02/05/1998
From:	NRC (Affiliation Not Assigned)
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ML20199L669	List: ML20199L666 ML20199L672
References
REF-QA-99900912 NUDOCS 9802100003
Download: ML20199L672 (13)

Text

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U.S. NUCLEAR REGULATORY COMMISSION i i i

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OFFICE OF NUCLEAR REACTOR REGULATION i

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2 Report No: 99900912/98-01 Organization: National Technical Systems, Inc.

i Acton, Massachusetts 4-  ;

Contact:

Christine Briggs , Vice President l Director of Quality j S08/263-2933 '

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Nuclear Activity

Provides commercial grade dedication and equipment qualification services and dedicated equipment for the commercial ,

nuclear power industry.

Dates: January 6 8,1998 i

4 Inspectors: Stephen D. Alexander, Reactor Engineer i

' Gregory C. Cwalina, Senior Operations Engineer Bill H. Rogers, Reactor Engineer l

i. Approved by: Robert A. Gramm, Chief Quality Assurance and Safety Assessment Section Quality Assurance, Vendor inspection and Maintenance Branch - '

Division of Reactor Controls and Human Factors i I

4 Enclosure P

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4 9902100003 900205 PDR GA999 EECNATTS <

99900912 PDR .

I ., . . . _ , , , . . . , , _ -... - _ . . , _ _ . . . . _ _ . _ . . . . . - . . . . . . . . _ . _ . . . . _ . , . . _ . , . _ , - . - . . . _ _ , _ . . . _ _ . . , ,

1 INSPECDON

SUMMARY

National Technical Systems (NTS), Inc., provices engineering and test services to industry and govemment. With a quality assurance (QA) program intended to meet the requirements of 10 CFR Part 50, Appendix B, NTS's Acton, Massachusetts, division has been a major supplier of basic components (both hardware and services) to the commercial nuclear power industry. In recent years NTS has been pi!marily involved in the procurement and dedication of commercial grade items for safety related 9pplications, including environmental and/or seismic qualification testing and analysis as rer',wred.

On June 9-12,1997, the NRC conducted an inspection at Pacific Gas & Electric Company's (PG&E's) Diablo Canyon Power Plant (DCPP) to review activities related to the procurement, modification, installation and testing of 4 kV circuit breakers of 350-megavolt ampere (MVA) interrupting capacity to re place most of the plant's original GE Mogne-Blast breakers of 250 MVA capacity (NRC Inspection Report No. 50 275,323/97201). NTS, Acion, was PG&E's prime contractor for the project. The replacement breakers are specially converted Type OGR SF, Gas Floupac Series, Rotary Arc,4.16 kV circuit breakers; rated at 1200 and 2000 A, continuous, with a 41 kA current interrupting rating, manufactured by the Yaskawa Electric Company, LTD. (Yaskawa) of Tokyo, Japan. The inspectors found that Yaskawa had made some modifications to the breaker's operating mechanism to facilitate the conversion, and that '

these modifications had been made subsequent to design verification testing of the original breaker done in accordance with applicable U.S. Industry stanoards (specifically, American IJational Standards Institute (ANSI) standards) to which PG&E had committed for DCPP. The inspectors also found tha' NTS had collaborated with a commercial switchgear services vendor, Power Distribution Services, Inc. (PDS), to accomplish the conversions, with NTS providing engineering support and nuclear QA coverage. NTS had the design and production testing performed on the complete conversion units prescribed by the applicable breaker conversion standard, to test the hardware added to the Yaskawa breaker, but took credit for some of the original design tests (in particular, the interrupting capacity tests) performed by Yaskawa. This was allowed by the conversion standard, provided engineering analyses could establish that the modifications by Yaskawa and PDS would not invalidate any design tests for which credit was being taken.

Yaskawa cerWied that none of the breakcr modifications would impact the results of the testing. NTS reviewed and evaluated the Yaskawa modifications and also concluded that the changes would not invalidate the results of the breaker tests. NTS also evaluated the PDS conversion modifications and concluded that either they also did not invalidate the design tests or were covered by the additional design and production testing prescribed by the conversion standard. In addition, PG&E had performed its own evaluations with the same conclusion.

However, based upon the informatior, available at Diablo Oanyon, the inspectors could not independently reach the same conclusion during the June 1997 NRC inspection. Therefore, the inspectors identified the need to review the NTS evaluations and other pertinent information during on inspection at NTS's Acton, Massachusetts, facility.

During this inspection of NTS, the inspectors assessed specific attributes and implementation of the NTS 10 CFR Part 50, Appendix B, QA program, specifically as it applied to the procurement modification / conversion and dedication of the replacement 4 kV breakers for DCPP.

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The inspection bases were as follows:

• Appendix B," Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," to Part 50 of Title 10 of the Code of Federa/ Regulations (10 CFR Part 50),

• 10 CFR Part 21,

• Reporting of Defects and Noncompliance."

During this inspection, the inspectors found no instance in which NTS failed to meet NRC requirements. The inspectors found that NTS's commercial-grade dedication of the Yaskawa modular assemblies, the conversion hardware and final conversion units was acceptable. The inspectors also found that the evaluations by NTS and PG&E of Yaskawa design changes and PDS conversion hardware were adequate to support takin0 credit for the Yaskawa ANSI interrupting capacity test.

2 STATUS OF PREVIOUS INSPECTION FINDINGS The NRC last performed an inspection of NTS in July 1993 (NRC Inspection Report No.

99900912/93 01). During that inspection, the NRC identified one violation, one nonconformance, one unresolved item and three open items. Resolution of those items is discussed below.

2.1 Molation 99900912/93-01-01 (Closeil)

Contrary to the requirements of 10 CFR 21.21(a), NTS procedures, adopted pursuant to the regulation, would not, as written, ensure that deviations or failures to comply would be properly evaluated. The procedure also lacked certain provisions required by the July 1991 revision of the regulation. In addition, the posted notice prescribed by the procedures lacked certain information required oy 10 CFR 21.6(b).

NTS provided a responses to Violation 99900912/93 0101 in a letter to the NRC dated December 23,1993, which stated that Quality Assurance Procedure (QAP) 1,

" Reporting Requirements Per 10CFR21," had been revised and that the NTS 10 CFR Part 21 posting had been corrected to meet the requirements of 10 CFR Part 21. The NRC inspectors reviewed Revision 4 of QAP 1, dated February 16,1996, and determined that it required employees to notify their supervisor of conditions which did not meet technical procurement specifications (deviations) and required NTS to evaluate identified deviations or notify the customer within the applicable periods of time as specified its 10 CFR Part 21. The inspectors observed the current NTS 10 CFR Part 21 posting and determined that the posting met the requirements of 10 CFR 21.6. The inspectors concluded that NT3's corrective actions had been adeqv.e and that the requirements of 10 CFR Part 21 regarding procedures and posting were being met.

2.2 Mq0conformance 99900912/93-01-02 (Closed)

Contrary to the requirements of Criteria Ill, V and Vil of Appendix B to 10 CFR Part 50, NTS prepared proceduras for dedication testing of K!6ckner-Moeller (K-M) molded-case 3

circuit breakers for the North Anna Power Station did not property incorporate design requirements because they did not specify a minimum duration for the full-load hold-in ,

test, and there was evidence that the test was conducted for an inappropriate time. "

NTS provided a response to Nonconformance 99900912/93 0102 in its December 1993 letter to the NRC which stated that WTS had performed a prompt evaluation of the safey significance of the issue and had concluded that there were no immediate safety concerns since the licensees' actual plant loads were less than 40% of the main breaker rated current. However, to provide for the potential occurrence that plant loads could be changed, NTS reported that it had conducted a commercial grade survey of K M and verified that K M had performed adequate testing to verify the full load capacity of the dedicated breakers. The inspectors concluded that NTS's corrective actions were adequate.

2.3 Unresolved item 99900912/93-0103 (Clgjid)

Out of tolerance tripping of certain K M overload' relays during NTS testing was attributed to age. The inspectors were not able to determine during the July 1993 inspection what the basis was for the K M revised trip time tolerances, nor what other installations might be affected by relays with similar age / shelf-life-shifted performance characteristics.

NTS provided a response to Unresolved item 99900912/93-0103 in its December 1993 lotter which stated that NTS had contacted K M, Commonwealth Edison Company (Comed) and its architect-engineer firm, Sargent & Lundy (S&L), to assist in resolving the issue. The S&L response letter to NTS, dated June 27,1994, stated the trip time curves used by NTS during the testing had been obtained from incorrect revisions of the drawings and were not applicable to the relays which had been tested. S&L stated that 3 when it had compared +.he relay test data to the correct trip time curves, it determined that most relays had met the required specification. S&L identified several relays which had not met specification and recommended that they not be used, it also identified several relays which were to be returned to S&L for adjustment. 3&L determined the relay test results which had been previously identified by NTS as early tripping should be considered acceptable (other than those test results which S&L had identified as not meeting specification) and that there was no indication of any age-related failure mechanism. The Comed letter to NTS, dated June 27,1994, concurred with the S&L conclusions. The inspectors concluded that NTS had established an acceptable basis for the acceptance of the previously identified trip-time characteristics of the K M relays and had taken adequate corrective action to resolve the apparent anomaly.

2.4 Open item 99900912/93-01-04 (Closed)

NTS had properly reported performance anomalies of Z4-100/K-NA overload relays which wore identified by NTS during environmental qualification testing to K M and to NTS's customers. However, there was insufficient laformation to determine how or if NTS, K-M, or affected customers had evaluated any effects these anom61ies might have on existing installations in harsh environment, Class 1E applications. '

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NTS provided a response to Open item 99900912/93-014 in its December 1993 letter to the NRC which stated that NTS had contacted Comed and S&L to assist in resolving the Ics;3. The S&L letter to NTS, dated May 5,1994, stated that S&L had evaluated the testing occurrenca during which a Z4-100/K NA overload relay tripped at 135'F while raneping down from she posk temperature of 170'F. The unexpected tripping did not 7

occur when the test was repeated for the relay which had previously tripped nor did it occur dwing the testing of tr.e other relays. S&L reported it had performed an kva! cation and analysis ud concluded that the unexpected tripping had been a random occurrence that did not affect the use of the relay type in the intended application. The Comed le' tar to NTS, dated Nay 16,1994, concurred with the S&L conclusions. The inspectorF ranW F.ai >1TS had established an accrotable basis for the acceptance of the qualifit,ation :/1he K-M telays and had taken adequate corective action to resolve the identified snomaly.

2.5 Qgenitem 99900912/93-0105 (Closedi NTS haa not evaluated the impact of environmental qualification test failures of Continental silicone rubber insulated electrical cable on installations, if any, of this cable in C10s *E, harsh environment applications, but it had reported the failt es to its only customer for the tests, Spectrum Technologies. There was insufficient information for the inspectors to determ.no whether Spectrum or Continental had performed such an evaluation either.

Spectrum had provided an evaluation of the test failures in a letter to the NRC dated March 28,1994. The letter stated that Spectrum had contracted NTS to perform the qualification tests in oroer to support a Northem States Power Company (NSPC) order to Spectrum for qualification and dedication of certain Continental electrical cable.

Spectrum had purchased commercial grace cable from Continental and provLied samples to NTS for aging and qualification testing. When the cable failed the qualification tests, Spectrum discontinued further qualification or dedication of this particu:ar cable type, returned the cable to Continental and advised NSPC of the results.

NSPC revised its purchase order to substitute Rochbestos cable (previously qualified by Rockbestos) which Spectrum purchased from Rockbestos on the basis of a successful 10 CFR Part 50, Appendix B, audit. In addition, the Spectrum letter emphasized that the Continental cable was never considered qualified rior dedicated and was not delivered to the customer. The inspectors concluded that NTS had taken adequate action in notifying Spectrum of the identified anomaly and that Spectrum hcd correctly concluded that the cable had failed qualification and had properly notified the potential end user.

2.6 Open Item 99900912/93 01-06 (Closed)

During the July 1993 NRC inspection at NTS, the inspectors identified that, during NTS qualification testN of certain Static-O-Ring (SOR) pressure switches, one sample had developed a pressure leak during a high-energy line break (HELB) test, and another sample had suffered excessive leakage current during a dielectric withstand test. The inspectors found no documented evaluation by NTS or SOR of the root cause of the test failure or evaluation of the irapact, if any, on existing safety related applications.

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Following the NTS inspection, SOR provided the NRC its complete qualification report for the switches which had not been available at NTS. In the report, and with clarification provided during subsequent telephone conversations with the NRC, SOR reported that it had found that the ieakage path was provided by unsealed mounting bracket screws for the micro switch (switching element) mounted in the switch housing.

SOR had evidence that the screus had not been resealed after the micro switch was readjusted during factory calibration. Failure to reseal the screws allowec the switch diaphragm (seat) to be over pressurized during the test which caused it to leak. SOR stated that since other switches with the same type of housings did not suffer a similar test failure, the test failure was attributable to a random occurrence, not to an inherent weakness in the design. SOR's corrective action consisted of (1) resealing the micro switch mounting screw threads if the micro switch was readjusted during factory calibration, and (2) applying a primer to the micro switch bracket screws to improve the curing of the thread sealant in the stainless steel housings of the potentially affected switch models. SOR confirmed that applicable safety related pressure switches installed in plants were not compromised because the corrective measures had been instituted before production.

Regarding excessive leakage current in one sample: the inspector observed that the SOR pressure switch test specimens passed the dielectric withstand test at 1500 Vac for 1 minute, except for one sample that experienced about 2 milliamps (mA) of leakage current at 900 Vac. SOR could not find a root cause and believed that the 2 mA leakage current was a random anomaly and not indicative of a common failure mode.

SOR's basis was that the other specimens (1) passed the test at 1500 Vac, (2) had adequate insulation resistance at 500 Vde, and (3) had sufficient margin for service conditions because the switches were rated for 250 Vac and typically used in 120 Vac or 125 Vdc applications. The inspector determined that on the basis of information provided by SOR, and because leakage current from moisture intrusion would typically have been higher than 2 mA, the anomaly was satisfactorily addressed, 3 INSPECTION FINDINGS AND OTHER COMPENTS 3.1 10 CFR Part 21 Progtgm 5

a. Insoection ScQR2 The inspectors reviewed the effective NTS 10 CFR Part 21 implementing procedure required by 10 CFR 21.21(a), QAP 1, " Reporting Requirements Per 10CFR21," Revision 4, dated February 16,1996, and the posting required by 10 CFR 21.6. The purpose of the limited Part 21 review was to verify that NTS had implemented the corrective actions reportod and proposed in its response to the previous Notice of Violation (99900912/93-0101), had updated its Part 21 procedure to reflect the revision to the regulation that became effective in November 1995 (to the extent applicable to NTS scope of activities) and to confirm continued compliance with the requirements of 10 CFR 21.21(a) and 10 CFR 21.6.

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b. Observationtand Findinos The inspectors found that QAP 1 now appropriately required employees to notify their supervisors of conditions which do not meet technical procurement specifications (deviations) and required NTS to evaluate identified deviations or notify the customer of the deviations within the applicable periods of time as specified in 10 CFR Part 21. The inspectors observed that the current NTS posting required by 10 CFR 21.6. consisted of 10 CFR Part 21, Section 206 of the Energy Reorganization Act of 1974, and a notice stating the location of the NTS 10 CFR Part 21 implementing procedure and the name of the person (s) to whom the report should be made.

The inspectors determined that NTS had not performed any 10 CFR Part 21 evaluations since the 1993 NRC inspection.

c. Coaclusions Within the limited scope of th,3 review, the inspectors concluded that NTS had implemented appropriately revised procedures required by 10 CFR 21.21(a). Further, the posting required by 10 CFR 21.6 was constructively in compliance with the regulation.

3.2 Convenign and Deslan Verification of 4-kV Circuit Breakers

n. Insnection Scoce The inspectors assessed attributes and implementation of the NTS 10 CFR Part 50, Appendix B, QA program as it applied to the procurement modification / conversion and dedication of the reolacement 4 kV breakers for DCPP Specifically, the inspectors examined 1) NTS's evaluation of design changes made by Yaskawa subsequent to ANSI type testing,2) design documents for the complete conversion, and 3) NTS/PDS design and design verification activities.

The review included evaluating NTS activities with regard to oversight of manufacturer and PDS design, design verification, commercial quality controls and production testing.

In addition the inspectors reviewed NTS activities relating to the manufacturer's modifications to the original breaker, fabrication of adapting hardware by PDS, prototype testing and production of the final breaker assemblies,

b. Observations and Findinos NTS used a " modular assembly" conversion approach in accordance with standard C37.59-1991, *lEEE Standard Requirements for Conversion of Power Switchgear Equipment." of the American National Standards Institute (ANSI) and the Institute of Electrical and Electronic Engineers (IEEE). This approach comprised adapting a modular assembly, defined by the standard as the circuit breaker operating mechanism, the interrupting devices, interconnecting hardware and supporting frame, by fitting the modular assembly (supplied by Yaskawa)into a carriage with the assdciated equipment 7

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for electrical and mechanical interface with the existing (Magne-Blast) breaker cubicles.

This composite unit is what the standard calls the " complete conversion."

b.1 Yaskawa Desion Chanaes: During the review of the design documents relating to Yaskawa design changes, the inspectors noted that Yaskawa had made several changes to the modular assembly delsgn subsequent to the ANSI iype testing.

Based upon interviews of cognizant NT6 staff and examination of representative parts of a Yaskawa circuit breaker mechanism, the inspectors identified those modifications that had some potential for affecting breaker performance in the area for which original design testing had not been repeated and for which credit was being taken. The design changes of interest included (1) lengthening the trip levers, (2) replacing the original single stage Interrupter bottle gas pressure switch with a two stage unit (for sequential alarms on lowering SF6 pressure, (3) replacing the original trip and close coils with stronger ones, (4) replacement of certain stamped, machined and/or welded parts with investment castings. The inspectors found that the post design testing changes made by Yaskawa either would have no effect on interrupting capacity or were validated by the subsequent C37.59 design and production testing performed on the complete conversion as follows:

In order to accommodate the linkage used in the complete conversion for the rackout interlock which trips the breaker (ifit is not already open) when either beginning to disconnect the breaker frorn the bus in racking down or when beginning to rack the breaker up into the connect position, Yaskawa fabricated special trip levers, elongated by about 1 inch. The subsequent timing tests confirmed that this modification had no adverse effect on the tripping time.

With regard to the interrupter bottle gas pressure switches, h inspectors found that the original single stage or setpoint switches had been replaced by Yaskawa with two-stage or setpoint swirches. However, the new switcher nad lower contact ratings for continuous load current as well as load current interrupting. By review of the NTS/PDS and PG&E design drawings (circuit diagrams) and technical information for the loads controlled by the pressure switch (the largest of which was 'n time delay relay), the inspectors determined that the contact ratings of the replacement switches were adequate, in addition, the inspectors' independent assessment of the NTS failure modes and effects analysis for the pressure switches confirmed that the credible failure mode if the contacts were underrated would be possible welding of the contacts, in this case, the low gas pressure alarm (and possibly also the low-low-pressure alarm) would be actuated, allowing the breaker to interrupt at least one more time (even if SF6 pressure were actually as low as 1 atmosphere), but preventing recharging of the closing spring, thus preventing subsequent automatic or remote operations.

With regard to the trip and closing coils, the inspectors determined that Yaskawa had replaced the original 60-ohm coils with coils of 30 ohm DC resistance coils (thus drawing more current), but with sufficient tums to make the ampere-tums product greater than that of the original coils, thus allowing the coils to develop more magnetic force on the armature / plunger. The inspectors noted that this change vivould tend to 8

improve breaker performance, particularly timing, and thus not hvalidate previous testing.

With regard to the originally machined, stamped and/or welded parts that Yaskawa had replaced with investment castings, the inspectors determined that the process and materials used, which had been reviewed by NTS during its commercial grade surveys of Yaskawa, produced parts that w" > ' strong and durable as those in the ANSI-tested version. In addition, the suit -, of the investment castings was further confirmed during post modification o, ,gn verification and production unit testing.

b.2 Conversion Hardware: The inspectors then reviewed the design documents for the complete conversion, interviewed cognizant NTS staff and examined representative parts of a Yaskawa circuit breaker mechanism. Design documents reviewed included Yaskawa and PDS/NTS drawings, failure modes and effects analyses, component technicalinformation, and testing procedures and records.

During the review of the design documents for the complete conversion, interviews of cognizant NTS staff and examination of representative parts of a Yaskawa circuit breaker mechanism, the inspectors identified the hardware added by NTS/PDS to form the complete conversion. Of particular interest was that which had some potential for affecting breaker performance in the area for which original design itsting had not been repeated and for which credit was behg taken. The added hardr 3 e ofinterest included (1) the trip and close riser linkages for the cubicle interloa ts, (2) the linkages and plunger assemblies that operate the stationary auxiliary switch (SAS' munted in the cubicle or cell and (3) 10-Ohm,0.62 Henry chokes (inductors) inst . series with the trip and spring-release coils,.

The inspector noted that the trip riser interlock linkage (of particular interest) acts to raise the trip lever instead of being raised by ti and then only during racking up or down, not during breaker opening. The inspector also examined the design and hardware and confirmed that the presence of the interlock linkages did not impede the motion of the trip lever when it is operated by the trip solenoid during a remote electric trip, whether automatic or inillated by an operator.

With regard to the SAS linkage and plunger driven by the mechanical position indication mechanism, which is driven by the main contact linkage, the inspector noted that during the breaker closing cycle, when the breaker mechanism drives the SAS plunger : pward, the plunger strikes the operating rod of the SAS in the cubicle and, in moving it upward to actuate the SAS, it causes the SAS reset spring to be compressed. This action stores energy that, when released, acts to help open the breaker. Thus, the inspector noted that when the trip mechanism initiates a tripping operation, the SAS is already pushing downward on the breaker mechanism-operated plunger, helping it open the breaker and overcoming any additionalinertia that was added by the small mass of the SAS plunger and associated linkage. Although driving the SAS plunger has the potential to retard the closing operation (but not interrupting capacity), post modification design verification and production unit testing established that this additional hardware did not have a noticeable effect on timing. '

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PDS installed approximately 0.25 Henry inductance chokes in ser'es with both the trip and spring release coils. This also added 10 ohms DC resistanco to the circuit. The intended effect of the chokes would be to limit inrush current or re', M its rise, thus slowing the breaker's response to spurious trip signals that might come from protective relays that seismic testing had indicated would chatter e'.cessively (i.e. > 2 msec contact bounce)in a severe earthquake. In addition, measure', had been taken to prevent the spurious signals, such that the chokes w?re technically no longer required. However, the chokes wou!d also limit the maximum steady state current available after about five inductance / resistance time constants (a few milliseconds). Test data in the NTS files indicated that with the chokes, the time required to open the breaker was approximately 59 milliseconds at 70 Vde, well below the 125 Vdc nominal control voltage at DCPP.

This is less than the 5 cycles (about 83.5 milliseconds) allowed by design specifications within which the breaker must be able to clear a fault, b.3 - Desian and Desian Verification The inspectors confirmed that NTS and PDS completed the design and production testing prescribed by C37.59 on the complete conversion units with satisfactoiy results. However, not all of the design verification tests prescribed in ANSI /IEEE design standard C37.09, " Test Procedure for AC High Voltage Circuit Breakers Rated on a Symmetrical Current Basis," were repeated. In particular, the short circuit interrupting test et full rated voltage was not repeated. Therefore, PG&E took credit for certain design verification testing conducted on the SF, breaker by "1skawa, the original breaker manufacturer. The NRC had confirmed through consultation with the ANSI /IEEE Switchgear Committee subcommittee responsible for the con *;ersion standard, C37.59, that it allowed this approach, i.e., not repeating certain design tests (in this case, the interrupting capacity test), as stated above, provided that it is established through engineering analysis that none of the changes to the modular assembly or hardware added to the modular assembly in order to create the complete conversion (done in this case by Yaskawa and PDS respectively) willinvalidate the original ANSI design testing

c. Conclusions The inspectors Jetermined that NTS activities with regard to evaluatbn of Yaskawa design changes, design and constreution of the complete conversion, and design verification of the complete conversion was adequate to assure that the replacement tweakers were capable of performing their intended safety function.

3.3 Redication of Yaskawa Modular Assemblies and PDS Conversion Hardwanit

a. insoection Scooe To evaluate the dedicat;on process, the inspectors first reviewed NTS Procedure No.

6043195N, Revision 3, August 3,1995, *Dedicction/ Acceptance Basis for Class 1E Retrofit Circuit Breakers 4kV,350 MVA for Diablo Canyon Power Plant Units 1 & 2, Pacific Gas & Electric Company." Because certain critical characteristics were accepted on the basis of commercial-grade surveys, the inspectors reviewed reports NTS/ CGS /94-015, "NTS Quality Department Commercial Grade Survet Report," ,

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Revision 2 (June 15,1995) and NTS/ CGS /94-015A, *NTS Quality Department Commercial Grade Follow-up Survey Report," Revision 1.1 (August 15,1995). In addition, the inspectors reviewed the NTS dispositions of the survey findings and also a repter,entative sample of Piece Part Verification Data St.eets.

b. Observation and Findinas b.1 CIincal Chaiacteristics of Yaskawa Modular Assemblies NTS Procedure No. 6043195N prescribed the dedication process and called for use of a variety of dedication methods, including special tests and inspections, commercial grade survey of the suppliers and source verification. NTS dedicateo the Yaskawa modular assemblies (purchased as commercial grade) by identifying and verifying the assembly's critical characteristics. NTS performed a failure modes and effects analysis (FMEA) on the critical compovnts of the Yaskawa circuit breakers in order to identify the critical characteristics net essary for the breakers to perform their intended safety function. NTS's evaluation determined that the Yaskawa circuit breaker contained 134 piece parts which have critical safety functions. Further review of the 134 parts identified 36 critical characteristics. NTS then identified ?" specific piece parts / assemblies which collectively encompassed all 36 cntical characteristics. NTS conducted a performance-based commercial grade survey of Yaskawa in order to evaluate quality and manufacturing controls for the 22 re-ts which covered all critical characteristics, in addition, the 22 parts were selectea k. ;over major components of the completed modular assembly, including the operating mechanism (8 items), primary circuit assembly (9 items) and control circuit items (5 items). The survey reports included Piece-Part Verification Data Sheets which listed the part evaluated and identified the critical characteristics, the Yaskawa work operating standard that controlled the manufacturing process for the characteristic, the method used to verify each characteristic, and acceptance criteria. The data sheet also included a remarks

< section which provided specific information regarding the survey tecm member's observations. The inspectors' review of the representative sample of the data sheets did not identify any concems.

The commercial grade survey reports documented the results of the two commercial grade surveys performed on June 20-24,1994 (94-015) and October 24-28,1994 (94-015A), respectively. The second survey was performed to complete some activities that NTS was not able to perform during the first survey and to follow-up on findings and open items identified during the first survey. The surveys assessed several Yaskawa design and manufacturing processes, such as design control, procurement control, material control, manufacturing and process controls, inspection and test control, and measuring and test equipment.

The inspectors noted that NTS identified several findings and open items during the initial survey. All of the findings and open items were closed satisfactorily during the second survey. The surveys identified the need to include specific requirements in the NTS purchase order to (1) assure Yaskawa informs NTS of any significant desigr' changes that could affect the breaker's form, fit, function, or materials', and (2) specify 11

NTS requirements designed to supplement Yaskawa standard quality practices, in s addition, NTS identified the need to perform some tests and inspections to supplement the control and verification of some critical characteristics performed by Yaskawa.

As a result of the review of NTS's disposition of the survey findings, the inspectors determined that the basis for accepting the Yaskawa's corrective actions was edequately documented. The inspectors had no concems regarding the commercial grade surveys of Yaskawa.

b.2 Fasteners The inspectors reviewed NTS activities related to the fasteners used in the Yaskawa modular assemblies and in the NTS/PDS complete conversion. The fasteners used in the complete conversion had been provided by NTS/PDS and had been specified as SAE Grade 5 (hex head cap screws). The inspectors reviewed Procedure No, 60431-95N 1466 FAS,

• Receipt inspectiori and Sampling Procedure for Safety Related Fasteners for the PG&E Retrofit Circuit Breakers," Revision 2, dated January 1,1996, which provided !nstructions to verify the acceptability of fasteners by including receipt inspection, thread dimensional verification, magnetic testing, hardness testing, and materials analysis of the safety related fasteners.

All fasteners used in the Yaskawa modular assembly had been purchased from a Japanese Industrial Standard (JIS) supplier. A JIS supplier is approved by the Japanese Ministry c' international Trade and Industry (MITI). Suppliers are approved based on their ability to provide a specific product in accordance with the applicable JIS Standard (the standards specify necessary quality and technical attributes of products and materials and their manufacture). A manufacturer or supplier is only approved after MITI investigates the supplier's quality assurance program and process control for compliance to the standard. Following approval, the supplier is permitted to place a JIS mark on the approved commodity. The JIS mark is not transferable across company or pmduct lines. The inspectors reviewed documentation available at NTS which described the JIS Marking System and the authorities, responsibilities and processes used by MITI. The fasteners provided in the Yaskawa modular assemblies had been supplied as original circuit breaker components and had been identified as "4T." The fasteners had been procured from a MITI approved JIS supplier, in addition, NTS had tested a representative 4T fastener, determined it to be equivalent to SAE Grade 2 and acceptable for the application.

In addition, during a telephone discussion with NTS and the NRC inspectors, PG&E indicated that PG&E had reviewed the existing breaker cubicle, duplicated the cubicle, installed the complete conversion using the provided NTS fasteners, and had performed a seismic test which qua:ified both the fasteners used in the modular assembly and those used in the complete conversion. PG&E had determined, as verified by testing, that the modular assembly and the complete conversion was capable of performing its safety function under the design commitments. The inspectors concluded that the NTS/PDS and PG&E had taken adequate action to verify the suitability of the fasteners used in the modular assemblies and the complete conversions.

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c. Conclusions The inspectors determined that the NTS commercial grade survey verified that Yaskewa's commercial quality program was documented and effectively implemented.

The surveys examined Yaskawa's controls and processes for individual components and specific critical characteristic and provided rasurance that the NTS identified critical characteristics were properly controlled.

3.4 EntraDce and Exit MottlDSA At the entrance meeting on January 6,1998, the NRC inspector discussed the scope of the inspection, outlined the areas to be inspected, and established interactions with NTS managentent and staff. In the exit meetings on January 8,1998, the inspectors discussed their findings and observations.

4 PARTIAL LIST OF PERSONNEL CONTACTED NIS Timothy J. Rotti, Division Manager Christine C. Briggs, QA Msnager Keith Pogarian, Project Engineer Daniel R. Cannon, Project Engineer National Quality Assurance. USA James E. Dozier, Regional Manager PG&E Mohsin Kahn, Principal Engineer ITEMS OPENED, CLOSED, AND DISCUSSED C101td 99900912/93-01-01 VIO Failure to meet 10 CFR 21.21(a) and 21.6 requirements 99900912/93-01 02 NON Failure to incorporato design requirements in dedication testing 99900912/93-01-03 URI Determine basis for revised trip time tolerances for K-M relays 99900912/93-01-04 OPEN Evaluate performance anomalies seen in K M relay testing 99900912/93-01-05 OPEN Determine impact electrical cable test failure 99900912/93-01-06 OPEN Determine impact of SOR pressure switch test failures 13

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