IR 05000352/1990004
| ML20006B829 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 01/26/1990 |
| From: | Anderson C, Roy Mathew NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20006B821 | List: |
| References | |
| 50-352-90-04, 50-352-90-4, NUDOCS 9002050389 | |
| Download: ML20006B829 (5) | |
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U.S. NUCLEAR REGULATORY COMMISSION
REGION I
i Report No..
50-352/90-04 g
Docket No.
50-352 License No.
NPF-39 l-Licensee:
Philadelphia Electric Company 2301 Market Street Philadelphia, Pennsylvania 19101 Fasility Name:
Limerick Generating Station, Unit 1 Inspection At:
Philadelphia Electric Engineering Offices, Wayne, Pennsylvania Inspection Conducted: January 5-17, 1990 Inspector: -
O' b /k Ocbew
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G o
R.' K. Mathew, Reactor Engineer, Plant Systems date Section, EB, DRS b
/ #6 fo Approved by:
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C. Jt Anderson, Chief, Plant Systems Section, date Engineering Branch, DRS Inspection Summary:
Inspection on January 5-17. 1990 (Inspection Report No.
50-352/90-04)
Areas Inspected: Special, cnnounced inspection to review potential violations identified during inspection 50-352/89-12 dated July 28, 1989 regarding the Appendix R safe shutdown capability of the plant in the event of a fire.
Results: Two of the safe shutdown deficiencies previously discussed in inspection report 50-352/89-12 were determined to be potential violations.
These items include:
1) Four examples of possible failure of RCIC for safe shutdown _ using method R (Remote Shutdown Method) in the event of a fire, and 2) Possible failure of RWCU valve controls causing loss of reactor coolant inventory in the event of a fire.
l lDR0020503s9 900126 q
ADOC 05000352 PDC d
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DETAILS 1.0 Persons Contacted i
1.1 Philadelphia Electric Company (PECO)
E. Boscola, Test Engineer, Fire Protection i
N. Fioravante, Project Engineer
J. Halt, Engineer, NED R. Krich, Licensing Head A. Marie, Branch Head, Reliability and Risk Assessment D. B. Neff, Licensing Engineer B. Scholz, Manager, Engineering Specialties i
G. Stewart, Engineer, Supervisory, Licensing i
- V. Warren, Engineer, Site
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1.2 U.S. Nuclear Regulatory Commission C. Anderson, Chief, Plant Systems Section
- S. Pu11ani, Senior Operations Engineer
- Denotes those not present at the exit meeting (via telephone).
2.0 Background
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During August 27-31, 1984 and Jan. 23-27, 1989, the Nuclear Regulatory Commission (NRC) performed inspections to assess the licensee's Appendix R
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safe shutdown capability in the event of a fire.
Sruequently, the licensee
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identified several fire protection deficiencies.
loese were reported in con-
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struction deficiency reports (CDR's) and Licensee Event Reports (LER's).
These
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deficiencies were identified by the licensee as a result of a reanalysis and reevaluation of the safe shutdown program and Appendix R lessons learned from their Peach Bottom Station review. A management meeting was held at the licensee's Limerick facility on January 23, 1989 at the licensee's request to
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discuss several fire protection / safe shutdown deficiencies and their self assessment program to address these issues. The results of the assessment were
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discussed in a subsequent meeting with the NRC on March 15, 1989. The NRC reviewed the licensee's follow up actions during an inspection 89-12, dated July 28,1989. As a result of this inspection, the NRC concluded that even though these issues are technically resolved, they constitute potential viola-tion issues and would be subjected to further review by the NRC.
3.0 Purpose and Inspection Methodology
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An inspection was conducted on January 5-17, 1990 to review and determine if Appendix R safe shutdown items previously discussed in inspection report 89-12 constituted potential violations.
The inspector noted that 18 (section 3.1 items a-k of report 89-12) issues were previously identified as potential violations.
It was determined that two of these items were previously issued violations.
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During the inspection, the inspector examined the licensee's Fire Protection Evaluation Report (FPER), FSAR, mERs88-031, 89-02, 89-12,89-023 and 89-03 9, previous NRC reports 88-20, 89-12 and 89-06 and the licensee's corrective actions for the subject deficiencies.
The following section describes the applicable requirements and the associated deficiencies identified by the licensee and determined by the inspector to be potential violations of NRC requirements.
4.0 Review of Potential Violations Related to Safe Shutdown Capability Required by Appendix R Limerick Generating Station Operating License NPF-39, Condition 2.C(3)a requires that the licensee niaintain, in effect, all provisions of the approved fire protection program described in the FPER.
The FPER discusses the fire protec-tion program as it relates to nuclear safety and addresses conformance to CMEB 9.5.1 and Appendix R.
The licenseo's safe shutdown analysis provided in the FPER, states that systems needed for hot shutdown and cold shutdown are redundant and that all of the redundar.t systems needed for safe shutdown should be kept free of fire damage.
The FPER describes five safe shutdown methods designated as methods A,B,C,0 and R.
For a fire in any fire area, at least one of the methods will be available.
For a fire in the control complex, metnod R (the remote shutdown method) will be used.
The FPER requires that in the unlikely event that the control room becomes uninhabitable or if there is a fire in the cable spreading room or the auxiliary equipment room the plant can be shutdown from the remote shutdown panel. The FPER Section 3.2.1, Items 25 and 26 states, that during the post j
fire shutdown, the reactor coolant system process variables shall be maintained within those predicted for normal loss of ac power.
The shutdown capabilities provided for a specific fire area shall be able to achieve and maintain sub-critical reactivity conditions in the reactor to maintain reactor coolant inventory and achieve and maintain hot shutdown.
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Two potential violations of NRC requirements were identified during this inspection.
These potential violations are discussed below.
For each item, the applicable item number where this issue was previously discussed in inspection 89-12 section 3.1 is identified. The first potential violation consists of four examples of possible failures of the Reactor Core Isolation
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l Cooling (RCIC). The RCIC system is the only reactor coolant make up syctem specified in the FPER to maintain reactor water level for safe shutdown spe-cified for shutdown method R when there is a fire in the control complex.
Even though RCIC failure also affects shutdown method A, this method is not specified for a control room fire.
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4.1 Potential Violation Related to RCIC Unavailability During Safe Shutdown
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(Item a.1) Item number in Inspection Report 89-12, Section 3.1 where this issue was previously discussed.
The licensee identified that a fire in the control complex could damage the RCIC speed control and indicating circuits if damage occurs to the RCIC pump discharge line flow instrumentation before an operator can manually operate the transfer switches at the Remote Shutdown Panel (RSP).
Damage may occur such that the control of the RCIC from the RSP would be lost so that a hot shutdown cannot be achieved or maintained due to the lack
of isolation of control circuits.
This instrumentation is shown on
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Table A-22 of the approved FPER as the required instrument to achieve
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safe shutdown using method R.
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2.
(Item b.1) The licensee identified tne unavailability of the RCIC
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system due to insufficient protection of control and power cables in the control and reactor building enclosure for the RCIC inboard steam supply isolation valve (HV-49-1F007). The control and power cables for this valve are powered by Division III AC power. This power is described in Table A-22 of the FPER as the available power required for safe shutdowr using method R.
Fire damage to control cables for t
the RCIC inboard steam supply isolation valve (HV-49-1F007) could
close the valve.
Furthermore, damage to the power cables could t
prevent the valve from reopening rendering the RCIC system inoperable.
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(Item b.2) The licensee identified that a fire in the control complex could damage the HPCI control cables resulting in spurious actuation of HPCI, overfilling the reactor vessel and causing the water to carry over into the RCIC steam supply line rendering RCIC inoper-able. The HPCI system is required for shutdown method B.
The control cables for the HPCI system were not protected from fire areas for
shutdown methods other than method B.
No provision for isolating the HPCI system from the remote shutdown panel was provided.
This condi-
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tion affecting the RCIC system was not analyzed and hence safe shutdown could not be achieved using method R as described in the FPER.
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(Item c.1) The licensee identified that a fire in the control complex coula damage the control cabhs for the Feedwater header "B" inboard containment isolation valve (HV-41-1-F011B).
RCIC flow is discharged into the reactor vessel through the B loop of the Feedwater system.
Inadvertent closure of the valve due to control cable damage could isolate the fluw path for RCIC injection into the vessel render-ing the RCIC system unavailable for safe shutd,wn as described in the FPER.
The deficiencies described above identified by the licensee and verified by the inspector are a potential violation of the licensee's license condition 2.c.3,a (50-352/90-04-01).
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4.2 Potential Violation Related to Uncontrolled Blowdown of the Reactor Vessel A second potential violation regarding uncontrolled blowdown of the reactor vessel as a result of fire damage to the reactor water clean up (RWCU) system was identified by the licensee.
(Item e.2) The licensee identified that a fire in the control complex and reactor enclosure could damage the cables for RWCU valves HVC44-1F031, HVC44-1F033 and HVC44-1F034 or HVC44-1F035. This could result in the spurious opening of these valves and would create a blow down path from the reactor vessel to either the condenser or to the equipment drain tank.
This flow path could result in the loss of reactor coolant inventory beyond the make up cap-ability of the RCIC system causing an unanalyzed safu shutdown condition and safe shutdown of the plant could not have been assured.
This is a violation of the licensee's license condition 2.c.3.a (50-352/90-04-02).
The above deficiencies existed since the October 26, 1984 issuance of the Low Power Operating License, However, the licensee stated that they had shutdown methods available in addition to the methods described in the FPER to bring the plant to a shutdown condition. These are described in the licensee's alternate shutdown procedures and transient response implementation plan (TRIP)
procedures. The inspector noted that tne licensee's corrective actions for the above items are complete except for the RWCU valve spurious opening problem.
For this deficiency, the licensee has established roving fire watches for the affected areas and a modification is presently scheduled to be completed prior to startup from the third refueling outage.
The NRC review of the licensee's corrective actions were previously discussed in inspection report 89-12, 5.0 Exit Interview The inspector met with licensee management representatives (see Section 1.0 for attendees) at the conclusion of the inspection on January 17, 1990.
The inspector confirmed with the licensee that the report will not contain any proprietary information. The licensee agreed that the inspection report may be placed in the Public Document Room without prior licensee review for proprietary information (10 CFR 2.790). At no time during this inspection was written material provided to the licensee by the inspectors.
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