05000456/LER-2012-003
| Telephone Number (Include Area Code) | |
| Event date: | 06-03-2012 |
|---|---|
| Report date: | 02-18-2013 |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v)(C), Loss of Safety Function - Release of Radioactive Material 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4562012003R01 - NRC Website | |
CONTINUATION SHEET
U.S. NUCLEAR REGULATORY COMMISSION YEAtf4 1-1:=L R NE)j 2012 - - 01
A. Plant Operating Conditions Before the Event:
kJARRATIVE Event Date: June 3, 2012 Unit: 1 MODE: 1 Reactor Power: 99 percent Unit 1 Reactor Coolant System [AB]: Normal operating temperature and pressure No structures, systems or components were inoperable at the start of this event that contributed to the event.
Pertinent Containment Ventilation (VQ) VA Isolation Instrumentation:
Containment ventilation isolation instrumentation closes the containment isolation valves in the minipurge and normal purge systems. The action isolates the containment atmosphere from the environment to minimize releases of radioactivity in the event of an accident. Two radiation monitoring channels (1/2RE-AR011 and 1/2R E-AR012) provide input to the containment ventilation isolation. Each of the purge systems has inner and outer containment isolation valves in its supply and exhaust ducts. A high radiation signal from 1/2RE-AR011 initiates Train A containment isolation valves, which closes the inner containment isolation valves. A high radiation signal from 1/2RE-AR012 initiates Train B containment isolation valves, which closes the outer containment isolation valves.
The associated monitors for the 1/2RE-4R011 and 1/2RE-AR012 are the fuel handling incident area radiation [IL] monitors 1/2AR011J and 1/2AR012J. To maintain these radiation monitors operable, the radiation monitor setpoint must be within 10 mR/hr of containment background radiation levels. The basis for maintaining the alarm setpoint within 10 mR/hr is to initiate a containment isolation signal with a small rise in containment radiation level.
Description of Event:
On May 30, 2012, setpoint adjustments on 1AR011J and 1AR012J were performed. On May 31, 2012, 1AR011J was receiving alert alarms, and on June 1, 2012, setpoints were again adjusted on the 1AR011J and 1AR012J monitors.
On June 3, 2012 at 1200. Operations declared lAR011J Inoperable due to the detector drifting high. The required compensatory actions of Technical Requirements Manual (TRM) 3.3.p, "Radiation Monitoring Instrumentation, and Technical Specification (TS) 3.3.6, "Containment Ventilation Isolation Instrumentation" were implemented.
Additionally, because the detector would not be repaired four hours, TS 3.6.3, "Containment Isolation Valves," Condition A was entered. TS 3.6.3 Condition A is for one or more penetration flow paths with one containment isolation valve inoperable. The Required Action is to isolate the affected penetration flow path within four hours.
On June 3, 2012, at 1230, during a review of 1AR011J and 1AR012J performance, Operations determined that the setpoint for 1AR012J was not set in accordance with TAM 3.3.p and TS 3.3.6 requirements. The setpoint had previously been set incorrectly on June 1, 2012. 1AR012J was declared Inoperable, and compensatory actions were implemented. Additionally, with the setpoints for both 1AR011J and 1ARO12J exceeded, TS 3.6.3 Condition B was applicable. TS 3.6.3 Condition B is for one or more penetration flow paths with two containment isolation valves inoperable. The Required Action is to isolate the affected penetration flow path within one hour.
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