05000265/LER-2002-001
| Quad Cities Nuclear Power Station Unit 2 | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident |
| 2652002001R00 - NRC Website | |
FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6 PAGE (3) Quad Cities Nuclear Power Station Unit 2 05000265 (If more space is required, use additional copies of NRC Form 366A)(17)
PLANT AND SYSTEM IDENTIFICATION
General Electric - Boiling Water Reactor, 2957 Megawatts Thermal Rated Core Power Energy Industry Identification System (EIIS) codes are identified in the text as [XX].
EVENT IDENTIFICATION
High Pressure Coolant Injection System Uncoupled above 150 psig due to Misapplication of Technical Specifications
A. CONDITION PRIOR TO EVENT
Unit: 2 Event Date: March 4, 2002 Event Time: 1255 hours0.0145 days <br />0.349 hours <br />0.00208 weeks <br />4.775275e-4 months <br /> Reactor Mode: 2 Mode Name: Startup Power Level: 005% Startup (2) - Mode switch in Startup/Hot Standby position (or in Refuel position with all reactor vessel head closure bolts fully tensioned) with average reactor coolant temperature at any temperature.
B. DESCRIPTION OF EVENT
On March 4, 2002, at 0346 hours0.004 days <br />0.0961 hours <br />5.720899e-4 weeks <br />1.31653e-4 months <br />, Unit 2 entered Mode 2 for the startup from the 16th Unit 2 refueling outage (Q2R16). Overspeed testing on the High Pressure Coolant Injection (HPCI) [BJ] system was required due to work that had been conducted on the HPCI System. At 1145 hours0.0133 days <br />0.318 hours <br />0.00189 weeks <br />4.356725e-4 months <br /> preparations for the Unit 2 HPCI system turbine [TRB] overspeed test were started. At 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br /> Mechanical Maintenance workers started to uncouple the turbine for testing and by 1235 the turbine uncoupling was completed. The overspeed test was performed by approximately 1245 hours0.0144 days <br />0.346 hours <br />0.00206 weeks <br />4.737225e-4 months <br />, verifying that the HPCI turbine tripped in accordance with the acceptance criteria.
At that time, the Nuclear Shift Operator (NSO) initialed the reactor startup procedure to signify completion of the HPCI overspeed test. The reactor startup procedure was worded such that the reactor startup could continue and pressure could be raised above 150 psig after the HPCI overspeed test was performed, without mention of whether the HPCI turbine was coupled or not. Once the satisfactory results were received for the overspeed test, the NSO started raising pressure above 150 psig in accordance with the procedure.
At 1255, reactor pressure reached 150 psig and HPCI was declared inoperable. The NSO documented that Technical Specification (TS) 3.5.1, Condition F, which requires restoration of the HPCI system to operable status within 14 days, was entered.
TS 3.5.1 requires HPCI to be operable prior to exceeding 150 psig. The HPCI TS applicability is Modes 1, 2 & 3, with reactor steam dome pressure greater than 150 psig. The surveillance requirement for the low pressure HPCI test has a note that states that the surveillance is not required to be performed until 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after reactor steam pressure and flow are adequate to perform the test.
DOCKET NUMBER (2) LER NUMBER (6 FACILITY NAME (1) PAGE (3) (If more space is required, use additional copies of NRC Form 366A)(17) Raising pressure above 150 psig with HPCI uncoupled is incompatible with TS LCO 3.0.4 that states:
When an LCO is not met, entry into a MODE or other specified condition in the Applicability shall not be made except when the associated ACTIONS to be entered permit continued operation in the MODE or other specified condition in the Applicability for an unlimited period of time. This Specification shall not prevent changes in MODES or other specified conditions in the Applicability that are required to comply with ACTIONS or that are part of a shutdown of the unit.
In this case, the "other specified condition" was having reactor pressure above 150 psig. Entering this condition with HPCI not operable is not allowed by TS 3.0.4.
At 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />, reactor pressure was raised to 160 psig, where it remained until after 1520 hours0.0176 days <br />0.422 hours <br />0.00251 weeks <br />5.7836e-4 months <br />. At 1315 hours0.0152 days <br />0.365 hours <br />0.00217 weeks <br />5.003575e-4 months <br />, preparations for recoupling the HPCI turbine were started. By 1520 hours0.0176 days <br />0.422 hours <br />0.00251 weeks <br />5.7836e-4 months <br />, the HPCI turbine was recoupled and TS 3.0.4 was met.
On March 27, 2002, this event was discovered during a review of the operator logs associated with the startup process for Q2R16.
C. CAUSE OF EVENT
The root cause of this event was that licensed personnel misapplied TS 3.5.1 and did not consider TS 3.0.4 and its application.
As a contributing cause, the reactor startup procedural guidance was inadequate to ensure operable status of TS-required equipment when non-Mode conditions of applicability were entered.
D. SAFETY ANALYSIS
The safety significance of this event was minimal. Reactor pressure was held at about 160 psig until after HPCI was recoupled. Also, the low-pressure Emergency Core Cooling systems were available throughout this event, as were the Reactor Core Injection Cooling system and the Automatic Depressurization system.
E. CORRECTIVE ACTIONS
Corrective Actions to be Completed:
Training will be implemented on Technical Specification sections 1.0 (Use and Application) and 3.0 (LCO Applicability), including the lessons learned from this event, to reinforce that TS are always to be applied as written.
The reactor startup procedure will be revised to include guidance to verify and document operability prior to entry into non-Mode TS conditions of applicability.
FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6 PAGE (3) Quad Cities Nuclear Power Station Unit 2 05000265 (If more space is required, use additional copies of NRC Form 366A)(17)
F. PREVIOUS OCCURRENCES
No previous occurrences during the previous two years were identified involving a misapplication of TS by licensed personnel.
G. COMPONENT FAILURE DATA
There were no component failures associated with this event.