05000333/LER-2001-004
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3332001004R00 - NRC Website | |
FACILITY NAME (1) DOCKET (2) LER NUMBER (6) PAGE (3) James A. FitzPatrick Nuclear Power Plant 01 � 004 � 00 EDS Codes [ ]
EVENT DESCRIPTION
On March 19, 2001 at 0400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br />, reactor operators entered a 7 day Limiting Condition for Operation (LCO) per Technical Specifications (T.S.) Section 3.9.F.2 for scheduled maintenance on Low Pressure Coolant Injection (LPCI) motor operated valve (MOV) Independent Power Supply (IPS) Inverter 71INV-3B [EF].
Subsequently, On March 19, 2001 at 1100 hours0.0127 days <br />0.306 hours <br />0.00182 weeks <br />4.1855e-4 months <br />, operators entered a 14 day LCO per T.S. Section 3.9.B.3 for the removal of one of two Emergency Diesel Generator subsystems [EK] for scheduled inspection and surveillance testing. On March 20, 2001, at 1430 hours0.0166 days <br />0.397 hours <br />0.00236 weeks <br />5.44115e-4 months <br />, it was determined that the plant configuration of having both 71INV-3B and an EDG subsystem inoperable in the same safety division did not meet the design basis Loss-of-Coolant Accident (LOCA) analysis assumptions. Reactor operators entered T.S. Section 3.0.E LCO Action Statement requiring the plant to be placed in Cold Shutdown within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. On March 21, 2001 at 0054 hours6.25e-4 days <br />0.015 hours <br />8.928571e-5 weeks <br />2.0547e-5 months <br />, 71INV-3B was returned to an operable status and the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> LCO condition was exited. At the time, the reactor mode switch was in the RUN position with the plant operating at approximately 100 percent power.
T.S. Section 3.0.E states, in part, "When a system, subsystem, train, component or device is determined to be inoperable solely because its emergency power source is inoperable, or solely because its normal power source is inoperable, it may be considered OPERABLE for the purpose of satisfying the requirements of its applicable Limiting Condition for Operation, provided: (1) its corresponding normal or emergency power source is OPERABLE; and (2) all of its redundant system(s), subsystem(s), train(s), component(s) and devices are OPERABLE, or likewise satisfy the requirements of this specification....".
Initially, on March 19, 2001, reactor operators declared LPCI MOV IPS Inverter 71INV-3B and one EDG subsystem inoperable, but did not declare the B LPCI subsystem inoperable, based on the following conclusions for meeting T.S. Section 3.0.E:
1. The normal power source for the LPCI MOV bus associated with the LPCI MOV IPS is the 115 KV offsite power supply when the inverter is out of service and the MOV bus is powered from the alternate source.
2. The emergency power source for the LPCI MOV bus is the LPCI IPS.
3. The normal and emergency power source for the LPCI pumps are the 115 KV offsite power supply and the EDG subsystems.
4. When the affected LPCI MOV bus is energized from either its normal or emergency power source as described in 1 and 2 above, the motor operated valves associated with the LPCI MOV bus remain operable.
5. The LPCI pumps are operable when powered from either the normal (115 KV) or emergency power (EDG) source.
U.S. NUCLEAR REGULATORY COMMISSION 004 00 01 James A. FitzPatrick Nuclear Power Plant EVENT DESCRIPTION (cont.) However, following a plant configuration review on March 20, 2001, it was concluded that, given a postulated Loss-of Coolant Accident/Loss-of-Offsite Power (LOCA/LOOP), this configuration could result in a single Core Spray System [BM] pump available for low pressure emergency core cooling for some accident scenarios involving certain pipe break locations. This condition is not consistent with the assumptions in the LOCA analysis.
CAUSE OF EVENT
The cause for this event was inadequate guidance within the current T.S. and T.S. Bases for operator actions when placing a LPCI MOV Independent Power Supply in an inoperable condition. [Cause Code D] Current T.S. Section 3.9.F.2.c (Action Statement) requires an inoperable independent power supply be isolated from its associated LPCI MOV bus, and this bus be manually switched to its alternate power source. T.S.
should further require that any inoperable IPS subsystem make the associated LPCI subsystem inoperable.
EVENT ANALYSIS
This report is being submitted in accordance with 10 CFR 50.73(a)(2)(i)(B), "Any operation or condition which was prohibited by the plant's Technical Specifications...".
The LPCI MOV IPS System provides an independent power source for the operation of three motor operated valves in each of the two redundant Residual Heat Removal System — Low Pressure Coolant Injection [BO] loops and two motor operated valves in each of the two Reactor Water Recirculation System [AD] loops. The power supply system includes two separate and independent uninterruptable power supplies, each consisting of a rectifier/charger, a battery, an inverter, and associated MOV bus. If a LPCI auto-initiation signal occurs, the LPCI MOV IPS is disconnected from the AC emergency power system and both MOV IPSs supply power to the MOV buses through the inverters. In the event that the IPS is not available, the LPCI MOV bus can remain energized by an alternate power source.
The safety significance of having both the LPCI MOV IPS Inverter 71INV-3B and the EDG subsystem inoperable concurrently was determined to be low. This conclusion was based on:
1. The short duration of the event (37 hours4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br /> and 54 minutes); 2. The operability of the EDG subsystem in the opposite safety division to provide emergency power to its associated ECCS loads (A General Electric evaluation of representative BWR/4 plant concluded that one core spray pump will provide adequate core cooling to preclude exceeding peak cladding temperature for a design basis recirculation line break); and U.S. NUCLEAR REGULATORY COMMISSION 004 01 99 James A. FitzPatrick Nuclear Power Plant EVENT ANALYSIS (cont.) 3. The fact that, during the event, one emergency diesel generator within the inoperable EDG subsystem remained capable of supporting certain loads (i.e. one core spray pump and one residual heat removal pump) to the 10600 bus.
EXTENT OF CONDITION
The lack of Technical Specifications guidance, as addressed in the Cause of Event section of the LER, has been addressed and will be corrected with JAF's conversion from current T.S. to the Improved Technical Specifications. ITS implementation team reviews identified no similar T.S. LCO discrepancies.
CORRECTIVE ACTION
1. Operations management has communicated the details of this event to Senior Reactor Operators.
2. FitzPatrick has submitted a T.S. amendment application for conversion from current technical specifications to the Improved Technical Specifications (ITS) consistent with Improved Standard Technical Specifications (NUREG-1433, Revision 1). ITS and associated ITS Bases provide detailed guidance for operability considerations when dealing with LPCI Independent Power Supply subsystems and components, and on dealing with simultaneous system inoperabilities. ITS implementation is scheduled for the second quarter 2002.
3. A T.S. Interpretation has been generated to provide clarification to T.S. Section 3.9.F, LPCI MOV Independent Power Supplies.
ADDITIONAL INFORMATION
A. Previous Similar Events: � NONE B. Failed components: NONE C. Applicability to NEI 99-02, Rev. 0, "Regulatory Assessment Performance Indicator guideline.
This event is not reportable as a Safety System Functional Failure in accordance with NEI guidance.