ML20247J259
| ML20247J259 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 05/23/1989 |
| From: | Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20247J257 | List: |
| References | |
| 50-341-89-03, 50-341-89-3, EA-89-006, EA-89-6, NUDOCS 8906010083 | |
| Download: ML20247J259 (2) | |
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- NOTICE OF VIOLATION-Detroit Edison Company Docket No. 50-341 Fermi 2 Nuclear Power Station License No. NPF-43 EA 89-006 During an NRC inspection conducted on January 5-6, 13-14, and 25, 1989, violations of NRC requirements were identified. In accordance with the
" General Statement of Policy and Procedure for NRC Enforcement Actions,"
10 CFR Part 2, Appendix C, 53 Fed. Reg. 40019 (October 13,1988),the !
violations are listed below:
A. 10 CFR Part 50, Appendix B, Criterion XVI, requires that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective materials and equipment, and nonconformances are promptly identified and corrected.
Contrary to the above, on at least four occasions between December 23, 1986 and February 23, 1988, the licensee was notified of conditions adverse to quality and failed to correct such conditions in a timely manner. Specifically, the licensee was informed of the need to incorporate the manufacturer's recommendations for lubrication, maintenance, and maintenance intervals for all AK type circuit breakers.
However, the licensee failed to include such information in preventive maintenance procedures on the GE Type AKF-2-25 field breaker until November 1988 even though the maintenance was scheduled to be performed during this period.
B. 10 CFR Part 50, Appendix B, Criterion V, requires that activities affecting quality shall be prescribed by documented instructions, procedures, or drawings of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings.
MI-M037, " Recirculation Pump Generator Field Breater (GE TYPE AKF) General '
Maintenance," Revision 1 contained the licensee's approved instructions and checklist for " General Cleaning, Inspection, and Lubrication."
Contrary to the above, on March 16, 1986, when preventive maintenance was performed on the B recirculation pump motor-generator field breaker, the actual performance of such preventive maintenance was inadequate because lubricant was not added in the cam follower slot of the breaker as required by Procedure MI-M037. Revision 1.
These violations have been categorized in the aggregate as a Severity Level III problem (Supplements).
8906010083 690523 PDR ADOCK 05000341 O FDC
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.e l-Notice of Violation 2
- Pursuant to the provisions of 10 CFR 2.201, Detroit Edison Company is hereby required to submit a written statement or explanation to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, D.C. 20555, with a copy-to the Regional Administ'rator, Region III, U.S. Nuclear Regulatory Commission, 799 Roosevelt Road, Glen Ellyn, Illinois 60137, and a copy to the NRC Resident Inspector at Fermi 2 within 30 days of the date of the letter transmitting this Notice. This reply should be clearly marked as a " Reply to a Notice of Violation" and should include for each violation: (1) the reason for the violation if admitted; (2) the corrective actions that have been taken and the results achieved; (3) the corrective actions that will be taken to avoid further violations; and (4) the date when full compliance will be achieved. Where good cause is shown, consideration will be given to extending the response time. .If an adequate reply is not received within the time specified in' this Notice, an Order may be issued to show cause why the license-should not be modified, suspended, or revoked or why such other action as may be proper should not be taken.
FOR THE NUCLEAR REGULATORY COMMISSION W
A. Bert Davis Regiona1' Administrator Glen Ellyn, Illinois Dated this y Pa} day of May 1989
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o U.S. NUCLEAR REGULATORY COMMISSION REGION III ReportNo.50-341/89003(DRS)
License No. NPF-43 Docket No. 50-341 Licensee: The Detroit Edison Company 6400 North Dixie Highway Newport,-MI 48166 Facility Name: Fermi 2 Nuclear Power Station Inspection At: Fermi Site, Newport, Michigan Inspection Conducted: January 5-6, 13-14 and 25, 1989 N I Inspectors: .Date Ro A.7estberg
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ohn H. Neisler 7
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/ p' Date Approved.By: )Mh. 2-l'8T Date Ronald N. Gardner, Chief Plant Systems Section Inspection Summary 5-6, 13-14 and 25, 1989 (Re) ort No. 50-341/89003(DRS)},
Inspection on JanuarySpectal safety team inspection ),v two regionallnspectors Area.; Inspected:
and one Headquarter's inspector of onsite followup of events at operating reactor (93702).
Resulu: Two apparent violations Wre identHied. (Foilure to take timely.
corrective actions and ineffective corre::tive action, Paragraph 2b(5); and failure to follow procedures, P4ragraph 25(5)).
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DETAILS
- 1. Persons Contacted Detroit Edison Company (DECO)
R. Sylvia, Senior Vice President, Nuclear Operations
- W. Orser, Vice President, Operatinns S. Catola, Vice President, Nuclear Engineering and Services D. Gipson, Plant Manager F. Svetkovich, Assistant to Plant Manager
- T. Riley, Supervisor, Compliance A. Settles, Tech Supervisor
- D. Odland, Superintendent, Maintenance and Modifications P. Fessler, Director, Plant Safety
- R. Stafford, Director, Nuclear Quality Assurance and Plant Safety C. Cranston, Director, Nuclear Engineering L. Goodman, Director, Nuclear Licensing R. McKeon, Superintendent of Operations P. Anthony, Compliance Engineer C. Cassise, General Foreman, Maintenance
- J. Beard, Consultant U.S. Nuclear Regulatory Comission (NRC_)_
- A. Bert Davis, Regional Administrator, Region III
- E. G. Greenman, Director, Division of Reactor Projects
- H. J. Miller, Director, Division of Reactor Safety
- W. D. Shafer, Acting Deputy Director, Division of Reactor Safety
- R. C. Knop, Branch Chief, Division of Reactor Projects
- J. Stang, NRR ,
- T. Quay, NRR !
- B. Stapleton, Enforcement Specialist W. Rogers, fenior Resident Inspector S. Stasek, Resident Inspector
- Indichtes those attending the canagement/ exit raeeting in Region III offices on January 25, 1989.
- 2. Review of Recirculation Pump B Motor-Generator Field Breaker Failure Initiating Event Summary On January 4, 1989, at 2:50 a.m. (EST) during a normal unit shutdown with the reactor in Mode 3, a failure of the B Reactor Recirculation (RR) pump field breaker (ATWS trip breaker) occurred following a manual shutdown of the pump. RR pump B was tripped as part of routine preparation to place the Residual Heat Removal (RHR) system into the shutdown cooling mode of l
operation. Following the trip of RR pump B from the control room a fire was identified in the field breaker electrical panel local to the motorThe generator set. The fire was subsequently extinguished by operators.
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4 indicating lights in the control room for field breaker trip coils TC1 A work and TC2 indicated the field breaker had not tripped as required.
request was initiated and leads to the trip coils were lifted. Visual observation of the breaker revealed discoloration of both trip coils. ;
i In response to the event, two Regional inspectors and one Headquarter's inspector were dispatched to the site. In addition, Region III issued a Confirmatory Action Letter (CAL) which required the licensee to l quarantine the breaker, determine why the breaker would not open, and review the maintenance modification, procurement and operating history as potential contributors to the root cause of the failure.
The purpose of this report is to document the NRC staff's review of this event.
- a. Documents Reviewed (1) General Electric (GE) Maintenance Instructions (a) No. GEI-50299, " Power Circuit Breakers Types AK-2."
(b) No. gel-93863A, "AK Power Circuit Breakers Types AKF-2-25 and AKF-2A-25."
(2) GE Nuclear Services Information Letter (SIL) No. 448,
" Maintenance and Lubricants for GE Type AK Circuit Breakers."
(3) NRC IE Information Notice No. 87-12. " Potential Problems with Metal Clad Circuit Breakers, General Electric Type AKF-2-25."
(4) Deviation Event Reports (a) No. 88-0290, "NRC Concern on MG Set Field Breaker Failures."
(b) No. 89-0026, " Failure of Rx Recirc MG Set b Field Breaker Trip Coils."
(5) 14aintenance Instruction No. MI-M037, " Recirculation Pump Generator Field Breaker General Maintenance," Revision 1.
(6) MI-M037, " Recirculation Pump Field Breaker (GE Type AKF)
General Maintenance," Revision 3.
(7) Work Request No. B622871022.
(8) Drawing No. 61721-2104-3/4, " Internal Wiring Diagram M-G Set r Control Panel B31-P002A/28," Revision I. i (9) Drawing No. 61721-2105-16, " Schematic Diagram Reactor Recirc M-G Set A and B Gen Field Breaker Trip Circuits," Revision F.
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(10) Procedure No.- FMD-RA1, " Interfacing With. Regulatory ' Agencies-
-and Industry Organizations," Revision 0.
(11) Procedure No. FIP-CA1-01, " Deviation and Corrective Action -
Reporting," Revision 2.
(12) Procedure No. FMD.MA1, " Maintenance," Revision O.
(13) Procedure No. NPP-12.000.017, " Preventive Maintenance Program,"
Revision 10.
f (14)' Field Modification Request (FMR) No. 4110 for' Recirculation Pump Trip Portion of ATWS Utilizing Field Breaker Trip dated May 1983.
(15) Receiving Inspection Report (RIR) No. 719-6 for MG Set Electrical Equipment Cubicles dated July 16,-1973.
(16) Field Material Requisition No. 27123 for Breaker Trip Coils for B31-P002A and B dated November 7, 1983.
(17) NRC Generic Letter No. 85-06, " Quality Assurance for ATWS Equipment That'is Not Safety-Related," dated April 16, 1985.
(18) Confirmatory Action Letter No. CAL-RIII-89-01 related to failure of B Reactor Recirculation Pump Field Breaker dated January 5.-1989.
(19) Letter B. Ralph Sylvia to A. Bert Davis, " Interim Response to CAL-RIII-89-01," dated January 10, 1989.
'(20) Memorandum for J. M. Taylor, Director of Office of Inspection and Enforcement from J. E. Murley, Regional. Administrator, RI,
" Reliability of Nonsafety-Related Breakers During An ATWS,"
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dated January 20, 1937.
' b .- Inspection ReGuits (1) Background On Feb; wry 21, 1980, the NRC issued an Order requiring the installation of a recirculation pump trip (RPT) by December 31,19E0, to provide a diverse means of making the reactor subcritical in the event of an anticipated transient without scram (ATWS). Fermi 2 complied with the order by installing the required RPT during initial construction in May of 1983.
i The-Fermi 2 RPT stops the recirculation pump flow by opening the Motor-Generator (MG) set generator field breaker' associated l with each pump. The field breaker was modified to include a 4
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second shunt trip assembly which acts with the existing shunt trip to provide a two-out-of-two shunt trip for the ATWS function.
The MG field breaker used at Fenni 2 is a GE type AKF-2-25 power circuit breaker. The AKF-2-25 is a special type of AK-2 breaker, designed to switch shunt field circuits of synchronous generators and motors. It is a three pole air circuit breaker with the center pole position modified to serve as a field discharge switch through a resistor. The center pole is J operated by a compound linkage which connects fhe field j discharge resistor before the other two poles open. This allows the AKF-2-25 breaker to open the excitation circuit r i
The without shunt tripinducing coil (excessive voltage in the field winding.STC) the original STC are not rated for continuous duty and will overheat and fail if subjected to full voltage for more than a few seconds. Therefore, if the closing linkage or the armature binds or jams, the STC will overheat and failure will result.
(2) Removal and Inspection of Field Circuit Breaker The failed circuit breaker was a GE type AKF-2-25, i S/N 224A3518-735-2. The breaker had failed in a partially ,
tripped position. When the inspectors arrived, the breaker was still in its cubicle and in the partial tripped position.
The inspectors observed the removal of the breaker from its cubicle and participated in the breaker inspection in the electrical maintenance shop.
The licensee had arranged for two GE service representatives to assist in the breaker removal and inspection. The GE tervice representatives tripped the breaker and licensee electricians removed it from the cubicle. The breaker was rioved to the electric maintenance area for visual inspection.
Visual inspection revealed that the inboard shunt trip coil was burned and the outboard coil possibly damaged from heat generated by the burned coil. The eccentric bushing (GEI-93863. Figure 2, Item 12) appeared to be out of position.
It was not determined whether the eccentri.: bushing caused the 1 breaker to fail or whether the breaker failure caused the !
j eccentric bushing to slip out of position. The center pole
' contacts showed some evidence of arcing or wear indicating that these contacts may not have been properly aligned or adjusted. !
The breaker's bearings had a small amount of lubricant in each l bearing; however, no lubricant was visible on the cam followers I or other sliding surfaces as required by GE Service Information i Letter 448. Af ter inspection, the circuit brea'ar was crated for shipment to GE's Atlanta facility for root cause analysis, repair and refurbishment.
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. n .- y (3) Failure' of Replacement Circuit Breaker The licensee, subsequent to the initiating event, procured two replacement AKF-2-25 circuit breakers from'other nuclear facilities. These breakers were urgraded in the GE facility.
before delivery to Fermi 2. Both breakers were inspected and bench-tested before being installed.in their respective cubicles.
When the B circuit breaker was-functionally tested in the cubicle, the breaker, failed to close on the initial attempts. '
Investigation of_ the failure. revealed that' the trip handie' had been left in the up position mechanically preventing the breaker
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closure'. The trip handle was placed in the proper racked-in position and another attempt was made to close the breaker. . ,
T After the second failure to close, the licensee discovered a' blown fuse in the closing. circuit. The fuse was replaced and-two n: ore attempts to close the breaker were unsuccessful. The-breaker was removed from the cubicle to the electric maintenance u
area where, after consultations with GE, the front escutcheon plate was removed. Upon removal of. the front plate, it was discovered that the left closing spring was detached. The licensee was informed by GE that attempting to close-the breaker
.with the trip handle in the up position could cause detachment of. the closing spring. After inspection by the.NRC inspector, the breaker was sent to the GE Atlanta facility for repair.
The licensee replaced both recirculation pump moter-generator field breakers. Each AKF-2-25 breaker had been refurbished and r the required modifications and/or maintenance perfonned by GE. .
The breakers were bench tested by Fermi electrical personnel j and installed in.their respective cubic!es. After installation each breaker was cycled 14 times, recirculation pumps were started, and the breakers were tripped under load to verify the operability .!
1 of the ATWS trip function of the breakers.
1 (4) Review of Preventive Maintenance (PM) ;
Subsequent to the January 4,1989, event, it was detennined that PM had been perfonned in March of 1988'on the initial treaker that failed and that no PH had been performed o1 the A Train breaker to dete. ThL inspectcm. reviewed the
'. applicable documentation and interviewed key licensee personnel relathe to PM on the MG field breakers.
This produced the folloxing chronology:
(a) The MG field breakers were delivered to the site and receipt inspected in 1973. They were included as part of the MG electric cubicles.
(b) As a result of th 1983 failure of a similar breaker at the Pilgrim Plant (Significant Event Report (SER) No. 28-83),
PM task No. MM 1000, " Inspect, test, and lubricate the MG 6
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.a set field breakers," once every two refueling outages ;
f' L was incorporated into the PM program on June 20,.1984.
The task was never performed.
l (c) On December 23, 1986, GE issued Services Information Letter (SIL) No. 448 which gave the manufacturer's recommendations for lubrication, maintenance, and maintenance intervals for all AK type circuit breakers. ' In addition, a special grease, Molykote BR2, was recommended for the AKF type breakers for use in the cam follower slot. On February 13, 1987, the NRC issued IE Information Notice 87-12 which alerted the licerisee to previous failures of the AKF type breakers and repeated the recommendations of SIL No. 448.
On March 21, 1987, the Fermi Independent Safety Engineering Group (ISEG) issued a memorandum to include the review of notice 87-12 with SIL 448. As of March 1987, no PM had been performed on the MG set field breakers.
(d) On January 26, 1987, Maintenance Instruction No. MI-M037,
" Recirculation Pump. Generator Field Breaker General Maintenance," Revision 1, was approved for use. This instruction addressed the concerns of SER 83-28 (the Pilgrim Event); however, it did not address the recommendations of Notice 87-12 or SIL 448.
(e) In a memorandum dated September 24, 1987, the Director of the Division of Reactor Projects directed-the resident staff to determine (1) if Fermi 2 currently used GE AKF-2-25 field breakers in the recirculation pump trip circuits.
(2) whether the breakers had failed, and (3) what actions the licensee had taken in response to Information Notice 87-12.
The Fermi resident inspector documented the following in Inspection Report No. 50-341/88003: .
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This breaker type was used as the field breaker for the reactor recirculation pump MG set.
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-2. There had been no known failures of this breaker '
at /crmi 2, The licensee was incorporating the SIL recommendations
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referenced in the Information Notice during the month j of February (1938).
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The resident inspector intended to review the maintenance instruction once it was issued.
(f) During the inspection period of February 6, 1988 to March 31, 1988, the resident inspector continued to pursue the regional request dated September 24, 1987, 7
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~ dealing with preventive maintenance activities associated' with GE AKF-2-25 field breakers. The' inspector documented the following in Inspection Report No. 50-341/88006:-
- 1. The licensee had scheduled the breaker inspection at an "every other refueling outage" frequency instead of "every. refueling" as stated in the Information Notice.
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- 2. No'five year breaker' tear-down procedure or scheduling requirement existed.
- 3. The breaker inspections were scheduled for the current outage.
- 4. The discrepancy between the licensee and Information
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Notice, requirements was brought to the attention of
' maintenance personnel and DER 88-0290 was initiated on February 23, 1988.
In discussions with licensee personnel, the resident inspector also cautioned.the licensee to_ perform the PM in accordance with the manufacturer's recommendations.
(g) PM on the B field breaker was completed on March 16, 1988, using MI-M037, Revision 1, which did not contain the manufacturers recommendations for lubrication and maintenance intervals. Step No. 7.4.11. " General Cleaning, Inspection, and Lubrication," was marked as satisfactorily completed on the Maintenance Data Sheet; however, visual inspection of the breaker by the inspectors on January 5, 1989, indicated that there was no grease in the cam follower slot.
(h)~ MI-M037, " Recirculation Pump Cenerator Field Breaker (GE TYPE AKF) General Maintenance,"' Revision 3, which incorporated the SIL grease re commendations was approved for use on September 16, 1988.
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-(i) D? ring en inspection'of the ATWS mitigating systems in November of 1988, the inspector questioned the equivalency of Shell Dolium R grease to the Molykote BR2 grease' called out by the GE SIL. After the January 4, 1989, event it was apparent that Shell Dolium R was never used on the breaker. The licensee agreed to use the Molykote BR2 in the future.
(j) DER No. 88-0290 was closed on December 22, 1988.
Review of the DER by the inspectors indicated that the GE SIL recommendations had been incorporated into the PM program; however, the maintenance intervals were based 8
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on refueling outages instead of months; 'This item was
' discussed at-the January 25, 1989, management meeting and the licensee comitted to 12 months ~ or any convenient ~
outage long enough' to allow the PM to be completed.
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The staff found this acceptable.
(k) On December 21, 1987, Procedure No. FMD MA1,." Maintenance,"
Revision 0, was approved for use. Section 3.0 of_the
- . procedure states that preventive maintenance events shall be reviewed against manufacturer's recommendations the next time the preventive maintenance events are scheduled-to be performed and beginning in February 1988. Any deviations from manufacturer's recommendations shall be evaluated and justification documented at that time.
(1) In Inspection Report No. 50-341/87028, dated October 16 -
1987, the licensee was cited for failure to implement or implement on. schedule the PM program for a significant .
. number of components. The response to.this violation by Deco revised Procedure No. 12.000.17 to require "A" priority PMs, that are not completed in the month they are scheduled, to be identified and evaluated. In a further response, DECO stated that the PM evaluation fonn requires the evaluator to document what the plant' reliability and-operability impacts would be and what the safety significance was if the PM activity was not performed. The form was to be approved by an SR0 with concurrence of the Superintendent-Maintenance and Modification ~and an engineer.
Inspection Report No. 50-341/88007, dated April 22, 1988, identified the fact that the justifications provided by engineering to maintenance did not provide an adequate technical evaluation for rescheduling PMs.
w q (5) Conclusions on PM Program Based on a review of the items described in the chronology, the inspectors reached the following conclusions:
(a) No documented PM was performed on the M5 field breakers between 1973 and March of 1988. The breakers may have had PM ouring Preop /Startup but this could not be substantiated. The breakers were cycled during the performance of the. ATWS divisional Logic Functional Surveillance tests which complies with one of the manufacturer's recommendations in SIL No. 448. However, the recommendation was to do the cycling between maintenance and inspection events. For the B breaker this occurred once when the logic function was performed in April 1988 following the B breaker PM in March of 1988. For the A j breaker, this sequence of cycling never occurred; however, the breaker was surveillance tested / cycled in May 1986, (
September 1987, and April 1988. l 9
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f (b) As early as 1984, the licensee recognized the need to perform PM on the MG field breakers to assure reliability; however, PM task No. MM 1000 was never performed.
j (c) GE SIL No. 448'and Information Notice 87-12 did not receive j the proper amount of attention required to ensure a prompt review and incorporation into the PM program, if required, until discrepancies between the licensee's program and the '
notice were concurrently identified by the senior resident inspector and licensee personnel on February 21, 1988 and DER No. 88-0290 was issued.
(d) The licensee performed PM to the old procedure on March 16, 1988, which did not contain the manufacturer's recommendations, after being cautioned by the senior resident to assure that the new procedure was used.
(e) The PM applied to the B breaker was inadequate in that the breaker was not lubricated as required by procedure No. MI-M037.
(f) The corrective actions for the violations cited in Inspection Reports No. 50-341/87028 and No. 50-88007 were not effectively applied to the PM program relative to the MG field breakers because the justification for rescheduling the A breaker PM was technically inadequate.
The justification for deferring the PM on the A breaker was inadequate because it did not address the breakers' ATWS function and did not assess the impact on plant operability and reliability and what the safety significance was if the PM was not perfonned, as required by procedure No. NPP-12.000.0127.
(g) The apparent failure mechanism of the breaker failure was mechaaical binding. The intermediate causes of failure were lack of/or inadequate preventive maintenance, and failute to follow proceda:es/persornel error. The root ccuse of failure was lack of timely corrective action relative to industry or Regulatory Agency identified conditions adverse to quality.
Failure to tcke timely corrective action to correct recognized conditions adverse to quality as evidenced by 2b(5),(a)(b) and (c) is an exaniple of apparent violation of 10 CFR 50, Appendix 8, l
Criterion XVI. (50-341/89003-01A). '
Failure to ensure that the corrective actions taken to correct the previously identified violations in Inspection Reports No. 50-341/87028 and 88007 were both prompt and effective l
L as evidenceed by 2b(5)(f) is a further example of an apparent violation of 10 CFR 50, Appendix B, Criterion XVI (50-341/89003-01B).
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Failure to follow the procedures for deferring PMs, and perfonning the breaker PM as evidenced by 2.b(5)(e) and (f) is an apparent violation of 10 CFR 50, Appendix .B. Criterion V (50-341/89003-02).
4 (6) Safety Significance. !
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Under conditions indicative of an ATWS (failure of RPS, high reactor pressure, and low-low reactor level) the RPT and the Alternate Rod Insertion (ARI) are expected to occur automatically to reduce the pressure excursion and consequent steam flow to the suppression pool. Fermi 2 emergency operating procedures (EOPs) require manual run back and tripping of the RR pump if the RPT breaker fails to open. Tt.e operator can open the RR pump feed breaker from the control room or the feed breaker can also be tripped manually at the breaker's local panel.
If the RPT breaker fails to open, the plant loses one of its means to reduce the reactor power and the resulting steam flow to the suppression pool. There are other means to accomplish the same function. They may not all be relied on for the following reasons:
(a) Manual Reactor Scram - Since an ATWS presupposes that the RPS has failed, the manual scram cannot be depended upon.
(b) Backup Manual Reactor Scram - At Fenni 2, the use of the backup manual scram switches also cause a MSIV isolation which could cause a transient to get worse; therefore, they cannot be employed. Further, all Fenni operators are trained to never use the backup manual scram switches.
(c) Manual RR Pump Tr!p - As mentioned abcve, it is possible but loses time.
(d) ARI - This is an automatic system. If ARI fails to insert the rods automatically, there are no manual ARI initiation switches at Fermi 2. Further, the use of Rosemont trip units for both RPS and ARI has previously been determined to be unacceptable diversity by the NRC staff.
(e) Standby Liquid Control System (SLCS) - At Fenni 2 the E0Ps require the manual initiation of the SLCS before the suppression pool temperature reaches 110*F, if reactor power is above 3%. Based on existing GE studies, this would occur in about 170 seconds. However, if one RR pump fails to trip, the suppression pool would be heated at a faster rate because the reactor would be at a higher.1evel of power. A Region I study indicated that the suppression pool would reach 110 F in only 70 seconds under these conditions unless the operators take deliberate action to reduce reactor power. The time lag may be of significance 11
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- since the Diagnostic Evaluation Team report concluded that'
~t here was-a substantial ' difference _ in the ability.of the shift crews to effectively utilize the E0Ps during simulator scenarios. .
It appears that SLC injection would be required and in order to shut down the reactor _and keep it shut down, 10 CFR 50.62 requires that the SLCS have a minimum flow I capacity and boron content equivalent in control capacity to 86'ga11ons per minute of 13 weight percent pentaborate l solution. Fermi 2 does not currently meet this requirement { '
. and will not commit to perform the modification that will increase the boron concentration until nine months prior to startup following their second refueling outage.
There is no site spccific probabilistic Risk Assessment Study f (PRA) for Fermi 2; however, an independent estimate prepared by Region _I for a. typical BWR with one auto RPT. breaker per pump and assuming a mean RPT failure probability on demand of
.003 gave a core melt frequency between IE-7 and IE-8 per year.
They also assumed that given the higher failure probability
- rate for GE type AKF-2-25 breakers that the incremental core melt probability could increase by an order of magnitude for an event that is_ already considered a moderate risk to the plant.
Conclusion Because of the Backup Manual Scram switch anomoly, the lack of manual ARI initiation and trip unit diversity, the lower than 10 CFR 50.62 boron requirement and the unreliability of the GE AKF-2-25 MG field breaker, the Fermi ATWS design may not be effective in mitigating the consequences of an ATWS event at this time.
(7) Confirmatory, Action Letter (CAL-RIII-89,01)
Region III issued Confirmatory Action Letter (CAL-RIII-89-01) on January 5, 1989, to delineate those actions to be accomplished before startup of the Fermi 2 power plant. The specific actions included in the letter were:
- 1. Take those actions necessary to ensure that complete documentation of the "as found" condition of equipment being inspected is maintained.
-2.
Develop a step by step troubleshooting program to establish the root cause of the failure of the GE AKF-2-25 breaker to open. This program should include inspection of the breaker for incorrect parts, a review of past maintenance, modifications, procurement and operating history, and generic consideration of other AKF-2-25 or 12
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.A j similar breakers installed in the Fermi 2 plant. This program should be provided to the resident inspector's; office for review.
3,- Not disturb any components that offer a potential for
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being the root cause including power sources, switches,
.and solenoids which interface with the field breaker until such action.is authorized by NRC.
- 4. Except as dictated by plant safety, do not perform any troubleshooting activities until NRC inspectors are present to witness these activities.
-5.
Provide justification for use of Shell Dolium R grease
'(DECoStock'No. 895-0143) to lubricate the slot in the cam-link of the center pole of the AKF-2-25 breaker instead of-the MOLYK0TE BR2 grease which is a lubricant currently approved by GE.for use on the breaker.
- 6. ' GE SIL No. 448 and IE Infonnttion Notice 87-12, " Potential
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Problems with Metal Clad Circuit Breakers, General Electric Type AKF-2-25, recommend a' four point maintenance program to ensure proper operation of these breakers.. Relative to this program, demonstrate how your maintenance program implements the complete breaker overhaul and personnel qualification recommendations of these' documents, or provide justification'for not implementing these recommendations.
Submit to NRC Regiun III a formal report of your findings-
-7. and conclusions within 30 days of' receipt of this. letter.
The licensee's interim response of January 10. 1989, described their actions relative to the CAL- action items. The response was reviewed by Region III and the licensee's corrective actions-verified by the inspectors. The licensee's corrective actions were considered adequate to permit the restart of Fermi 2.
Region III' authorized the licensee to startup the plant on January 13, 1989. The licensee began a' routine plant start on January 13, 1989, and returned the plant to operating sutus.
- 3. Management Meeting On January 25, 1989, a management meeting was conducted in the Region III office between A. B. Davis and members of the NRC staff and W. S. Orser and members of the Deco staff. At this meeting, the MG set field breaker failure was. discussed relative to root cause, corrective actions and-programmatic considerations.
There were two major areas of disagreement between the NRC staff and the Deco staff as follows:
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- a. The NRC staff believed that the senior resident caused the Deviation l Report which evaluated the GE S!L and Information Notice 87-12 to be written while the Deco staff believed that they identified the problem and generated the DER.
This disagreement was settled during telephone conversations between the inspector, the Superintendent of Maintenance, and the senior resident on January 26 and 30 1989. Both parties now agree that although the senior resident acted as the catalyst, the problem was discovered concurrently through discussion held between DECO personnel reviewing the PM procedures for manufacturer's recommendations and the senior resident. As a result, DER No. 88-0290 was generated on February 21, 1988, which is the same day as the discussion took place.
- b. The DECO staff characterized the root cause of the breaker failure as personnel error which resulted in the breaker not getting lubricated. The NRC staff did not believe that this was the root cause but instead an intermediate cause of failure. They believed the root cause to be failure to take timely corrective action relative to previously identified problems adverse to quality.
There was been no discussion or changes in these opinions since the meeting.
- 4. Exit Interview The inspectors met with licensee representatives denoted in Paragraph I during the inspection and at a Management Meeting in the Region III office on January 25, 1989. The inspectors summarized the scope and results of the inspection and discussed the likely content of the inspection report. The licensee acknowledged the information and did not indicate that any of the information disclosed during the inspection could be considered proprietary in nature.
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