ML20203N332
| ML20203N332 | |
| Person / Time | |
|---|---|
| Issue date: | 04/29/1986 |
| From: | Merschoff E, Naidu K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| Shared Package | |
| ML20203N323 | List: |
| References | |
| REF-QA-99901043 99901043-85-01, 99901043-85-1, NUDOCS 8605050295 | |
| Download: ML20203N332 (10) | |
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ORGANIZATION: WESTINGHOUSE ELECTRIC CORPORATION PITTSBURGH, FENNSYLVANIA PEPORT INSPECTION INSPECTION NO.- 99901043/85-01 DATE: 11/10-14: 01/13-16 DN-SITE H0lmS- oE CORRESPONDENCE ADDRESS: Westinghouse Electric Corporation Nuclear Services Integration Division ATTN: T. Christopher, General Manager Monroeville Pittsburgh, Pennsylvania 15230 ORGANIZATIONAL CONTACT: M. A. Marlyn TELEPHONE NUMBER: 412-374-7504 NUCLEAR INDUSTRY ACTIVITY: Refurbishment of 480 volt circuit breakers used as Reactor Trip Breakers including installation of Undervoltage Trip Attachments.
ASSIGNED INSPECTOR: 6 7 K.' R. Naidu, Reactive Inspection Section (RIS) Date OTHER INSPECTOR (S): J. B. Jacobson, vember 10-16,1985)
APPROVED BY: .
MM!Mr E. W. Merschoff, C , RIS, Vendor Program Branch Date INSPECTION BASES AND SCOPE:
A. BASES: 10 CFR Part 21, Appendix B to 10 CFR 50.
B. SCOPE: Witness tests (11/10-14/85) of UnderVoltage Trip Attachments (UVTAs) which. failed at D.C. Cook 2, review the manufacturing history and ouality assurance records of the replacement UVTAs, obtain additional information on broken spring latches observed at Watts Bar and the mal-functioned UVTAs reported at Kewaunee on June 8, 1984 and November 7, 1985.
PLANT SITE APPLICABILITY: D.C. Cook Units 1 and 2 (50-315; 50-316),
Kewaunee (50-305), Watts Bar (50-390; 50-391).
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ORGANIZATION: WESTINGHOUSE ELECTRIC COPP0 RATION PITTSBURGH, PENNSYLVANIA REPORT INSPECTION NO.- 99901043/85-01 RESULTS: PAGE 2 of 10 A. Violations No violations were identified during this inspection.
B. Nonconformances No nonconformances were identified during this inspection.
C. Unresolved Items No unresolved items were identified during this inspection.
D. Status of Previous Inspection Findings The items of noncompliance discussed below were identified when the manufacturing operations were located at East Pittsburgh and are discussed in Inspection Reports 99900330/83-01 and 83-02. Since then, the activities for the manufacture of switchgear components and accessories for nuclear power plant applications have been transferred to the Seco Road facility (Docket No. 99901043). Documentation on actions taken by Westinghouse could not be retrieved readily. Westinghouse agreed to consolidate the information in an auditable form for the following items. This information will be reviewed during a subsequent inspection.
- 1. (0 pen) Violation (83-01): The violation. identified that a current copy of 10 CFR Part 21 was not posted. This violation remains open pending review of measures established to prevent recurrence.
- 2. (0 pen) Nonconformance (83-01, Item A): The nonconformance identified that from the available inspection records it could not be established that 21 replacement UVTAs received 100 percent quality control checks. This item remains open pending verification that adequate measures have been established to prevent recurrence.
- 3. (0 pen) Nonconformance (83-01, Item B): The shop order information issued for replacement UVTAs did not identify the applicable drawing revisions to be used for the required 100 percent inspection of
" critical items." Changes were verified to be documented in Shop Order 02.YN202 on August 8, 1983. This nonconformance remains open pending verification that adequate measures have been established to prevent recurrence.
- 4. (0 pen) Nonconformance (83-01, Item C): The nonconformance identified that Certificates of Conformance were on file for only five replace-ment UVTAs of the eight that have been shipped on Purchase Order No. 54X470254 to the McGuire site.
ORGANIZATION: WESTINGHOUSE ELECTRIC CORPORATION PITTSBURGH, PENNSYLVANIA REPORT INSPECTION NO.- 99901043/85-01 RESULTS: PAGE 3 of 10 This nonconformance remains open pending verification that Certificates of Compliance for the remaining three are available.
E. Inspection Findings and Other Comments
- 1. Review of UVTA Failures The inspector reviewed the status of the reported failures of UVTAs. UVTAs actuate to trip 480 volt circuit breakers used as Reactor Trip Breakers (RTBs).
- a. Background Information on UVTA Failures As a result of the February 22 and 25,1983, anticipated transients without scram (ATWS) events which took place at the Salem nuclear power plant, the NRC issued Bulletin 83-01 and formed a task fcrce to assess the generic implications of these events. During these ATWS events, the VVTAs on Westinghouse type 08-50 RTBs malfunctioned and caused the breakers to fail to open. On March 11, 1983, Southern California Edison reported that three RTBs at San Onofre Unit 2 and one of Unit 3 failed to open during testing of the UVTAs. These RTBs were manufac-tured by General Electric Company. As a result, the NRC issued Bulletin 83-04.
The actions of the task force resulted in the issuance of NUREG 1000 titled " Generic Implications of the ATWS Events at the Salem Nuclear Power Plant" and Generic Letter 83-28, delineating procedural and plant changes required.. Findings in NUREG-1000 were based, in part, on assurances that improved maintenance of the circuit breakers would improve the reliability of the VVTAs to an acceptable level for the short term, after which the longer term corrective actions would be implemented.
The longer term corrective ^ actions which were directed by NRC Generic Letter 83-28, had two major aspects related to the RTB/UVTAs: (1) the installation of a plant modification that provides for the automatic activation of the shunt trip coil of the RTB for any automatic reactor trip signal, and (2) relia-bility improvements in the RTB/UVTA based upon UVTA life testing by the vendor. The life test formed the basis for a UVTA replacement interval of 1250 cycles and a lubrication interval of 200 cycles. Westinghouse issued a purchase order to their East Pittsburgh facility to manufacture 187 replacement UVTAs intended to replace the existing ones.
ORGANIZATION: WESTINGHOUSE ELECTRIC CORPORATION PITTSBURGH, PENNSYLVANIA l t
REPORT INSPECTION No.- 99901043/85-01 RESULTS: PAGE 4 of 10 The recent failures at D.C. Cook Unit 2 involved RTBs that were refurbished by Westinghouse in July 1985 at the Assembly and Test (A&T) facility located at Seco Road, Monroeville. The refurbishment included the installation of new UVTAs. The Unit 2 RTB "A" that failed on October 29, 1985 experienced approximately 75 operations subsequent to the refurbishment.
The Unit 2 RTB "B" that failed the margin force test on November 3, 1985 experienced approximately 30 operations subsequent to the refurbishment. In this short time, both UVTAs suffered a loss of their trip output force.
- b. UVTAs supplied to Kewaunee Westinghouse supplied to Kewaunee nuclear power plant (Kewaunee)'
four UVTAs with serial numbers 02Y-N213 - 8, 9,10 and 11 with ,
operating coils rated for 48 volts DC along with Quality Release ~
(QR) 70517 dated April 16, 1984. Kewaunee held these UVTAs in storage until June 1984 when they were assembled on RTBs and tested.
The UVTA with serial number 02Y-N213-9 malfunctioned. The UVTA isas returned to Westinghouse. Examination of this UVTA concluded that some of the parts on the UVTA had been replaced. Westinghouse notified the NRC in a letter NS-EPR-2928 dated June 8,1984 that they performed an evaluation in response to the component malfunction, and determined that some of the components in the UVTA had excessive wear and therefore could not have been supplied by them.
Westinghouse further stated that they examined their quality assurance records associated with the production of the UVTA and determined that the UVTA fully conformed to the inspection criteria when it was examined prior to placement in a sealed carton and shipped to Kewaunee. Westinghouse stated that the defective UVTA had been reworked utilizing used and outdated parts without their knowledge.
- c. UVTA Failure at D.C. Cook On October 29, 1985, the reactor trip breaker (RTB) associated with Train "A" reactor protection system failed to trip the D.C. Cook Unit 2 nuclear power plant due to the malfunctioning of the UVTA.
The serial number of the UVTA is 02Y-N212-88. The RTB associated with Train "B" functioned properly and tripped the plant. However, on November 3,1985, the same RTB failed to pass the UVTA force margin test. (The RTBs are 480 volt DB-50 type circuit breakers which were manufactured by Westinghouse in the late 1960s and refurbished by Westinghouse in July,1985.) The serial number of
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0RGANIZATION: WESTINGHOUSE ELECTRIC CORPORATION PITTSBURGH, PENNSYLVANIA REPORT INSPECTION NO.- 99901043/85-01 RESULTS: PAGE 5 of 10 this UVTA is 02Y-N212-66. These UVTAs which are rated for 125 volts DC operation were removed from their respective RTBs and sent to the Assembly and Test Facility of Westinghouse located at Seco Road facility in Monroeville for further tests and evaluation. During November 11-15, 1985, these two UVTAs along with another UVTA taken from storage were subjected to extensive tests. Representatives of American Electric Power Company (AEP) participated in the test program. Representatives of the NRC observed the tests. The NRC inspectors observed a weld bead on the leading edge of the UVTA which failed (serial number 02YN 212-88) which restricted the free movement of the trip lever spring. Additional tests conducted by Westinghouse confirmed this as a probable cause. Westinghouse issued a Maintenance Advisory letter NS-NRC-85-3084 dated November 21, 1985, to all users of DB-50 type circuit breakers as RTBs, describing the D.C. Cook Unit 2 event and advising users to visually inspect the UVTAs for anomalies such as weld beads or notches or grooves in.
the leading edges of the UVTA base that would prevent the successful tripping of the RTBs. Westinghouse representatives informed the NRC inspector during this inspection that the tests on the UVTAs were complete and that they sent a draft of the evaluation report to AEP.
- d. UVTA Failure at Kewaunee On November 7, 1985, Kewaunee performed tests on DB-50 type RTBs as required by NRC Bulletin 85-02, which was. issued following the RTB failure experienced at D.C. Cook Unit 2, to establish the satisfactory functioning of the UVTAs for those plants which had not installed the automatic shunt trip. Two of the five RTBs (one spare) failed the 20 ounce margin test prescribed in the Bulletin. The UVTAs were lubricated after discussions with NRC personnel and the RTBs tested satisfactory. These UVTAs have coils rated for 48 volts DC.
- 2. Review of 50.55(e) Report On July 26, 1985, Tennessee ValTey Authority reported a Construction Deficiency (50.55(e)) to the NRC. The report stated that mainte-nance personnel at the Watts Bar nuclear power plant observed broken spring release latches on 480 volt DS-416 and DS-206 type circuit breakers manufactured by Westinghouse. The device is a metal piece which releases the charging spring permitting the circuit breaker to close. Upon receipt of an electrical signal to close the circuit breaker, a solenoid device is energized. A flapper device on the solenoid hits the spring release device, which in turn releases the charging spring. Twenty five spring latches out of a
't ORGANIZATION: WESTINGHOUSE ELECTRIC CORPORATION PITTSBURGH, PENNSYLVANIA REPORT INSPECTION NO.- 99001043/85-01 RESULTS: PAGE 6 of 10 total of 80,000 units manufactured were reported to have been broken between 1972 and 1984. Westinghouse traced the failures to the manufacturing periods of early 1975, April 1976 and early 1978, and attributed the failures to incorrect heat treatment of the device.
Westinghouse issued a Technical Bulletin NSID-TB-85-17 on August 14, 1985 and recommended the following corrective actions.
(a) Advise the responsible personnel that the breaker may be closed manually using the operator on the front panel of the breaker if the electrical closing does not occur on demand.
(b) For applications other than Westinghouse designed reactor trip function, the user should evaluate the situation to determine if this condition could affect safety.
(c) Inspect the latch levers during normal scheduled maintenance / ,
inspection of the DS type circuit breakers.
Corrective action taken to preclude repetition was to increase the radii on the curved surface of the device and lower the minimum acceptable Rockwell hardness limit.
- 3. Review of the Purchase Order for Replacement UVTAs The Nuclear Systems Integration Division.(NSID) of Westinghouse issued purchase order RPS 10177 dated December 29, 1983 to Westinghouse Electric Supply Company (WESCo) for the supply of 187 UVTAs. WESCo reissued the order as purchase order RPS 20054 dated January 9,1984 to Westinghouse East Pittsburgh, where the UVTAs were manufactured. The following information related to the items listed in the above purchase order, quantity for each item, Quality Release (QR) number, and the date of release:
- a. UVTAs with 48 volts DC coils drawing #23A9019G-75 Quality Item Release Date Number Quantity Number Released 1 20 N-69172 3/5/84 1A 20 N-70516 3/16/84 IB 20 N-71209 5/4/84 N-70537 1C 20 N-70520 5/4/84 ID 10 N-70538 5/4/84 l
's ORGANIZATION: WESTINGHOUSE ELECTRIC CORPORATION PITTSBURGH, PENNSYLVANIA REPORT INSPECTION NO.- 99901043/85-01 RESULTS: PAGE 7 of 10 ;
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- b. UVTAs with 125 volts DC coil drawing 23A9019G-61 Quality Item Release Date Number Quantity Number Released 2 20 N-69189 3/5/84 N-69174 3/28/84 2A 20 N-71210 4/16/84 2B 20 N-70539 5/23/84 2C 20 N-70540 5/23/84 2D 17 N-70541 5/23/84
- c. Document Submittal Forms (DSFs) were used as vehicles to review and approve procedures and drawings. Change order 001 dated February 1,1984 to Purchase Order RPS 10177 conveyed the ap-proval of DSF E-9719 which in turn approved the design document review for UVTA, critical drawing list and Order Handling Proce-dure NQD-377-01 Revision 1.
- d. Change order 002 dated March 5, 1984 released seven UVTAs for DB-50 circuit breakers. Two were shipped to Virginia Electric Power Company (Surry 1), four to Carolina Power and Light Company (Robinson-2) and one was put in storage.
- e. Change Order 003 dated April 9, 1985 was issued to approve DSFs E-1027 and E-6230 which approved procedure NQD-377 Revision 2. The following changes were incorporated in this revision:
(1) A typographical error was corrected. Item 18 (latch) on the " Critical Parts" (CP) list was corrected from 309C010H01 to 309C010H02.
(2) Item la was added to the CP list to distinguish between the VVTAs with 48 volts and 125 volts DC coils.
(3) The drawing part numbers for the UVTAs with 48 volt and 125 volt DC coils were added to provide clarity.
- f. NSID QA personnel from Monroeville inspected the batches of UVTAs as they were being completed at the East Pittsburgh facility and witnessed the testing of the devices at random.
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ORGANIZATION: WESTINGHOUSE ELECTRIC CORPORATION PITTSBURGH, PENNSYLVANIA REPORT INSPECTION NO.- 99901043/85-01 RESULTS: PAGE 8 of 10
- 4. Review of the UVTA Quality Assurance Records
- a. One hundred and eighty-seven UVTAs were manufactured at the Westinghouse East Pittsburgh facility in various batches of 20, 10 and 7. The Quality Assurance records which consist of the quality control checklists including electrical tests are available at the Assembly and Test (A&T) facility located at Seco Road, Monroeville. The records indicate that whenever a batch of UVTAs were manufactured the appropriate quantity of the critical components were retrieved from storage and inspected. A single quality control instruction (QCI) 37 lists twenty components considered critical for the assembly of the UVTAs, the drawing number for the items and the quantity. A signoff on the checklist indicates that 100% of the items were inspected and determined acceptable. On completion of the assembly, functional tests were performed including a dielectric test. Items not identified as critical components are listed on QCI-157. Records indicate that NSID QA personnel went to the East Pittsburgh facility to inspect the final UVTA assemblies and selectively witness the dielectric tests. A quality release (QR) was issued to document the serial numbers of the UVTAs accepted. The UVTAs were then packed in individual boxes for shipment.
- b. The inspector reviewed QR D-70538 Revision 0 dated May 4, 1984.
The QR stated that for Purchase Order RPS 10177, ten UVTAs with serial numbers 02YN212-82 through and including 91 were released for storage at WESCO in Monroeville. The QR listed the attributes which were inspected and determined acceptable, such as, visual inspection, cleanliness, operating electrical test record, performance test record, packaging, Certificate of Conformance, Certificate of Quality and Certificate of Critical Components.
- c. QR D-70538 Revision 1 dated March 22, 1985 indicated that UVTAs serial number 02YN212-82, 83, 84 and 85 were released for installation to Tennessee Valley Authority circuit breakers.
The intent of the revision was to document that six UVTAs were left in storage at that specific time.
- d. QR D-70538 Revision 2 dated July 29, 1985 indicates that six UVTAs in stock were released to A&T facility.
- e. Trip Report NPQA-84-147 dated May 7, 1984 documents the final surveillance performed on a batch of thirty-one UVTAs. 100%
inspection was performed on the following attributes:
ORGANIZATION: WESTINGHOUSE ELECTRIC CORPORATION PITTSBURGH, PENNSYLVANIA REPORT INSPECTION NO.- 99901043/85-01 RESULTS: PAGE 9 of 10 (1) All tru-arc retaining clips (2) Captive pin design ("c" ring)
(3) Machine finish of trip latch (4) Tack welding (5) Surface finish (6) Serial number (7) Witnessing test per Operating Procedure 920071 revision B on four UVTAs with serial numbers 0YN212-61, 75, 84 and 91.
The test results were acceptable. The serial numbers of the thirty-one were 02YN212-61 through 91.
- 5. Review of the D.C. Cook Refurbishment Records The RTBs from D.C. Cook Units 1 and 2 were refurbished at the A&T facility. This refurbishment consisted of inspecting the RTBs, documenting the initial findings, replacing unacceptable parts, replacing UVTAs, and documenting the results of final inspections.
A shop traveller was used to document the inspections. Procedure CGG-02-1985-1 Revision I was used to perform the inspections. Review of the records indicate that all RTBs were in acceptable operating condition before shipment.
F. Persons Contacted Westinohouse Electric Corporation Nuclear Services Integration Divison'(NSID) l Replacement Components Service (RCS)
J. Epstein, Manager Equipment Qualification Group J. Jelovich, Manager A. K. Deb, Engineer i C. Geiss, Engineer
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ORGANIZATION: WESTINGHOUSE ELECTRIC CORPORATION PITTSBURGH, PENNSYLVANIA REPORT INSPECTION N0.- 99901043/85-01 RESULTS: PAGE 10 of 10 Assembly & Test Facility (Seco Road)
- J. Hill, Manager R. Folino, Quality Assurance
- G. Krauter, Manufacturing Engineer
- P. Kushner, Quality Control Inspector
- A. Macrae, Manufacturing Engineer Quality Assurance Department J. Evans, Manager, QA NSID RCS Group F. B. Hyland, Manager B. F. Barnett, Quality Engineer T. Whalen, Quality Engineer Standards and Audits S. Cunningham, Manager Nuclear Products Division P. McManus, Manager Audits & Systems M. A. Marylyn, Manager S. Long, Senior Quality Assurance Engineer Nuclear Safety Department E. Figenbaum, Engineer
- Denotes those persons who did not attend the exit interview on January 16, 1986 at the conclusion of the inspection.
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