ML20235U708
| ML20235U708 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 09/30/1987 |
| From: | Mcdonald R ALABAMA POWER CO. |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| CIVP-A-108, CIVP-S-022, CIVP-S-22, NUDOCS 8710140211 | |
| Download: ML20235U708 (7) | |
Text
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J (;,1 4-c Alabima Power Company; h;*~
600 North 10th Strert Post Office Box 2641 -
Birmingham, Alabama 352914400 Telephone 205 250-1835 m
87 00T 5 A10159 h
in"ifga%en,
' Alabama Power the Southem electnic System
-10CFR50.49 L.
i September 30,11987 e
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! Docket' Nos.'50-348 50-364-y Dr. J. ' N. Grace U. S. Nuclear' Regulatory. Commission Region' II, ' Suite 3100 :
'101 Marietta Street N. W.
Atlanta, GA 30303 1
D ar Dr. -Grace:
Joseph M. Farley Nuclear Plant - Units 1 and 2-Environmental Qualification Meeting of September 24, 1987 A meeting was held on September 24, 1987_at the NRC Offices in Bethesda, Maryland to discuss the deviation from design of certain. cable splices used at Farley Nuclear. Plant on environmentally qualified equipment and the-potential. safety: significance associated with the use of these splices.
This 1etter~ provides a discussion of the splice issues as presented at the meeting; including the basis 'for Alabama PowerL Company's decision to
! continue operating both units of Farley. Nuclear Plant, future actions for ensuring that affected splices are restored to_ full compliance with design, and the status of testing on-the subject splices.
When a significant issue occurs at Farley Nuclear Plant Alabama Power Company's first concern is to establish confidence in the safety of the plant, then.to rapidly and methodically establish plans and resources to
. resolve the issue, and then to implement the resolution on a schedule that is accelerated to the extent-consistent with overall safety. With regard (to the splice issue, Alabama Power Company has acted rapidly,
- conservatively and within what we believe to be the requirements of the regulations. Alabama Power Company plans to continue to vigorously pursue
- environmental qualification (EQ) issues.
In concert with this approach, Alabama Power Company made the following commitments to the NRC at the
~ September 24, 1987 meeting:
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Dr. J. N. Grace September 30, 1987 U. S. Nuclear Regulatory Commission Page 2 1.
Alabama Power Company will not start-up Unit 2 from its projected 52-day refueling outage starting on October 3,1987 without assurance that Alabama Power Company has resolved all operating issues on EQ matters (i.e., EQ issues which affect operability) for Unit 2 with the NRC.
2.
Alabama Power Company will keep the NRC advised of any emerging operating EQ issues found in either Unit 1 or 2 not addressed in the September 24, 1987 meeting.
3.
Alabama Power Company will not start-up Unit 1 from the Spring 1988 refueling outage without reaffirming assurance that Alabama Power Company has resolved all operating EQ issues involving Unit 1.
4.
Alabama Power Company will take appropriate action if an operating issue emerges at any time on Unit 1 or Unit 2.
In December 1984, a safety evaluation was issued by the NRC concluding that Alabama Power Company's EQ program for Farley Nuclear Plant was in compliance with 10CFR50.49.
In 1986 and 1987, an INP0 evaluation and Alabama Power Company Quality Assurance audits respectively identified several findings related to the EQ program. These findings were expeditiously resolved.
In May 1987, a Vendor Information and Procurement inspection was conducted by the NRC with concerns identified on the EQ file documentation and the use of commercial grade parts in EQ systems. The above findings provided an indication that other issues potentially existed in the established EQ program at Farley Nuclear Plant.
Based on the indications discussed above, an extensive review of the Farley Nuclear Plant EQ program was initiated by Alabama Power Company in June 1987. This review included a re-review of test reports to ensure that the data to support qualification is available, a review of test reports and technical manuals to ensure that maintenance requirements for EQ equipment are specified in maintenance procedures and practices, a review of past corrective maintenance to ensure that the environmental qualification of equipment is being preserved, and a review of EQ problems experienced at other nuclear plants for relevance to Farley Nuclear Plant.
Based on the review of an NRC EQ Audit Report on another nuclear facility and discussions with various maintenance and construction personnel, Alabama Power Company determined on July 16, 1987 taat cable splices configured in a V formation (V-splices), which is a deviation from the design, potentially existed on ASCo solenoid valves as the cable connection mechanism rather than in-line taped splices or Raychem configurations. A JC0 was prepared and the V-splice on solenoid valves which were accessible were replaced with Raychem splices that were in accordance with the design.
In conjunction with establishing the plan associated with ASCo solenoid valves, it was determined that the V-splice issue might be applicable to other categories of equipment. Concurrently, consideration
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l Dr. J. N. Grace September 30, 1987 U. S. Nuclear Regulatory Commission Page 3 l
of the available information relating to V-splices led Alabama Power Company to conclude that the splices in question would perform their intended function. Upon review of the situation, Alabama Power Company determined the following two approaches could be taken with this potential issue:
1.
A justification for continued operation (JCO) could be developed based on previous test data concerning V-splices, which could envelope V-splice configurations in the plant, or 2.
Having evaluated the capability of the subject splices to perform their intended function, a more conservative methodology (i.e., a methodology involving the development of JCOs, the inspection of splices, and replacements as necessary to restore to the approved design) could be adopted and applied to problems discovered in each category of equipment.
The more conservative JC0 methodology was adopted as the general approach for the V-splice issue. The categories of equipment to which the V-splice issue would potentially be applicable were defined and prioritized to serve as a corrective action plan extending beyond the solenoid valve actions already initiated.
The technical justifications for Alabama Power Company's decision that the taped V-splices in question would perform their intended function were based on (1) qualification test data, (2) protection afforded to preclude exposure of the splices to direct spray, (3) the use of materials which are qualified for in-line splice configurations, and (4) engineering judgement.
With regard to the qualification test data, an evaluation was performed considering Wyle Report 17859-02P (Qualification Test Program for Commonwealth Edison Company's PWRs). This test report provides qualification information on V-shaped splices using T95 insulation tape and
- 35 jacketing material that were subject to moisture incursion since the crotch of the V was not filled with any insulating material. The test specimens were subjected to an accelerated thermal aging equal to 40 years plant life, radiation exposure of 200 MRads gamma, and a design basis accident profile with a peak of approximately 360 F and 58 psig.
Alabama Power Company believed that the splices would not be directly exposed to spray because the splices are contained inside termination boxes, conduits, or other enclosures.
Since moisture incursion into the taped V-splice under postulated accident environments was a potential concern, Alabama Power Company considered the shielding of the splice from direct spray to be a significant factor. Additionally, the materials used by Alabama Power Company for the V-splices were expected to be qualified materials.
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Dr. J. N. Grace Page 4 September 30, 1987 U. S. Nuclear Regulatory Commission 1
Small amounts of leakage currents could be postulated to occur as a result of. the V-splice configuration. Since these splices were not expected to be installed on instrument circuits where leakage currents could significantly affect the function of the circuit, it was concluded through engineering
. Judgement that small leakage currents were not significant with respect to equipment operability.
Based upon these technical justifications and engineering judgement, Alabama Power Company believed the V-splices would perfonn their intended function when exposed to the relevant environment.
Accordingly, Alabama Power Company has never declared equipment inoperable due to the V-splice configuration. Therefore, Alabama Power Company believed, and continues to believe, that the continued operation of Units 1 and 2 of Farley Nuclear Plant is safe, is acceptable, and does not represent a potential risk to the health and' safety of the public or Farley Nuclear Plant employees.
On July 24, 1987, an evaluation was initiated on certain motor operated valve (MOV) motor-lead splices that were potentially installed in the V
-configuration. A JC0 was developed for these MOVs utilizing the following groupings: 1) MOVs outside containments or the main steam valve rooms; 2)
MOVs inside containments or the main steam valve rooms, with no post accident operation; 3) MOVs inside containments or the main steam valve rooms, with short-term post accident operation; and 4) MOVs inside containments or the main steam valve rooms, with long-term post accident operation. For the fourth group of MOVs, Alabama Power Company decided the actual' configuration of each of these valves had to be determined and either replaced with a configuration in accordance with the design or a further JC0 developed based on past test reports.
All of the valves in the fourth group were placed 'in a configuration in accordance with the design by July 31, 1987..In total, 40 of 60 MOV motor-lead splices have been replaced. on Unit 1, 26 of 74 MOV motor-lead splices have been replaced on Unit 2, and replacements on accessible MOVs are continuing even though JC0s may not require near-term replacements.
On August 4,1987, an evaluation was initiated on ten fan motors inside containment on each unit that potentially contained splices which were a deviation from the design. A JC0 was initiated and, at the same time, action was initiated to inspect each fan motor and correct any splice configurations identified to be a deviation from the design. The decision to inspect and make necessary replacements was considered a more conservative measure than waiting for the development of a JCO. Upon commencement of the inspection, Alabama Power Company decided that the work could be completed prior to the completion of the JC0 and efforts on the JC0 development were stopped. Multiple inspection / replacement teams were utilized on each shift to expedite the schedule and to minimize personnel radiation exposure and heat stress. Additionally, only one component was taken out of service at a time to minimize the collective number of safety l
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g Dr.'d. N. Grace September 30, 1987 U. S. Nuclear Regulatory Commission Page 6 systems out of service at a time. All ten fan motors on each unit were placed in a configuration in accordance with the design during the period from August 7,1987 to. August 22, 1987.
On September 15, 1987, an evaluation was^ initiated on 4160V motor terminations that potentially contained splices which were a deviation from j
the design. The. scope of this potential deviation from design involved the l
charging pumps, RHR pumps, and containment spray pumps on each unit.
Subsequently, the V-splice configuration was approved by design for applications not in a post accident steam environment. These pumps are not 1
in a post accident steam environment. Alabama Power Company. decided to j
destructively inspect each of these splices to determine if splice materials and dimensions were correct. The charging pump splice inspections on each unit are complete.
Due to the V-splice issue identified on solenoid valves, Alabama Power Company recognized the potential for a splice problem on the electrical connection to the. hydrogen recombiner heaters and scheduled an evaluation of this potential problem. The NRC expressed concern about this potential problem during the Region II inspection performed the week of September 14, 1987.
In response to the concern expressed by the NRC, Alabama Power Company elevated the priority of this potential problem and developed a JC0 for.the expected splice configuration. This JC0 was reviewed by the Plant Operating Review Committee and approved on September 18, 1987. The lA recombiner was inspected on the afternoon of September.18,1987 and j
confirmed to be in the expected configuration (i.e., one field wire bolted to.five heater leads and taped with Okonite T95 insulating tape.with Okonite #35 jacketing tape over the T95 tape). The NRC questioqed the September 18, 1987 JCO. A revised, more detailed, JC0 was subsequently prepared and provided to the NRC, which is still under review by the NRC.
Additionally, Westinghouse provided by letter dated September 22, 1987 the original' splice test configuration for the Farley Nuclear Plant hydrogen recombiners. The configuration used during the test was a taped splice similar to the as-found 1A configuration. Alabama Power Company is currently pursuing with Bechtel Eastern Power Company and Raychem Company a design that will resolve the concerns with this connection.
Alabama Power Company plans to continue to evaluate splices for EQ equipment and components as follows:
1.
600V f an motors outside containment.
2.
Instrumeni.ation inside and outside containment such as transmitters, level switches and radiation monitors.
3.
Containment electrical penetration terminations.
4 Any other equipment or components that could potentially De spliced or terminated as a deviation from design.
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Dr.LJ.: N. Grace September 30, 1987 j
.U. S. Nuclear Regulatory Commission Page 6 j
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As determined.necessary by these reviews : splices and ' terminations will be.
replaced consistent with the design. All: known ' work, inspections and '
walkdowns willibe completed with evaluations performed by the end of the ;
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.next refueling outage on each unit.
. In addition to the JCOs prepared and corrective actions taken,- Alabama j
' Power Company initiated an expedited test program of. V-splices.. At the -
time of the-Septemb'er. 24,1987..' meeting, the splices had successfully
. completed radiation exposure and thermal aging. test.s, and had successfully endured exposure to the peak temperature and pressure of the accident environment. 1Also at the time of the meeting, the splices were being
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- exposed -to a post-accident soak environment.- with the majority of the chemical
- spray exposure test-completed. No failures had been reported.
- Alabama Power Company ~ noted that testing was scheduled for completion on September:25,l1987.
. All qualification testing was successfully completed on September 25, 1987. 'The qualification test results were submitted to Alabama Power
- Company by letter from'Wyle. Corporation dated. September 28, 1987. The results of the. testing presented.in the letter states that all of. the test specimens demonstrated the capability. to conduct the specified currents at
'the specifiedfvoltages-throughout the test. The letter concluded that the test. specimens _ are qualified to the. intent of IEEE Standard 323-1983, "IEEE Standard for Qualifying Class 1E Equipment for Nuclear Power Generating Stations.":
At the September 24, 1987 meeting with the NRC, Alabama Power Company was requested to provide in this letter a discussion of walkdowns to be conducted. Walkdowns inside containment relative to the splice issue will be conducted during the next refueling outage on each -unit at Farley Nuclear Plant. The walkdowns will include a sample of components in representative equipment categories which are subject to the splice issue.
The. scope of these walkdowns will include instrumentation, penetrations, and any. Other categories of equipment determined by reviews to be subject to the splice issue. The Unit 2 walkdown will begin during the first full week of the outage and will be completed as soon as possible (currently estimated to be within two weeks from initiation). Alabama Power Company is developing a subset of the walkdown plan which will identify a smaller
.. sample of the equipment / components with field wiring connections in order to quickly identify significant issues. This subset of equipment is anticipated to be inspected in three to four days from the beginning of the walkdown.
Alabama Power Company will provide this detailed schedule of the Unit 2 walkdown to the NRC Region 11 Resident inspectors. Additionally, Alabama Power Company will continue to ensure that the Resident Inspectors are kept informed of our continuing EQ efforts and any further EQ issues that are identified.
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- Dr. J. N. Grace,.
September 30, 1987 U. S. ' Nuclear Regulatory Commission Page 7 If there are any questions, please' advise.
Respectfully submitted, ALABAMA POWE p?
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R. P. Mcdonald RPM /LCT: dst-T.S.7 cc: Mr. L. B. Long.
Mr. E. A. Reeves Mr. W. H. Bradford U. S. Nuclear Regulatory Commission
-ATTN: Document Control Desk Washington, DC 205S5 l
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