Event Notification Report for November 28, 2012

60-DAY OPTIONAL TELEPHONIC NOTIFICATION OF INVALID SYSTEM ACTUATION

"This telephone notification is being made for an invalid actuation under 10 CFR 50.73(a)(2)(iv)(A) following the reporting guidance of 10 CFR 50.73(a)(1) and is not considered a Licensee Event Report.

"With Unit 2 at Cold Shutdown (about 105?F and depressurized), an invalid actuation of the Unit 2 'A' train of the High High Consequence Limiting Safeguards (Hi-Hi CLS) system occurred at 2305 [EST] during reinstallation of fuses in preparation for return to service testing. The fuses were pulled to implement a design modification to replace existing relays with a new design. The 'A' train of the High High CLS actuated as soon as the fuses were installed. Plant systems and components responding to the Hi-Hi CLS 'A' train signals started and functioned successfully as designed with the exception of those systems and components procedurally rendered inoperable due to the RCS being below 350?F and 450 psig. Shutdown cooling was not lost due to safety injection leads being tagged out.

"The signal could not be reset from the Main Control Room due to system design in this configuration requiring manual local manipulations to address affected components. The relays on both trains were replaced with the original design and the fuses reinstalled. The affected systems were restored to their pre-event configuration.

"Specific trains and systems that actuated as a result of the "A" train of Hi-Hi CLS signal are described below:
-- Component Cooling from the A Reactor Coolant Pump isolated.
-- Containment Spray realigned and gravity flowed the Refueling Water Storage Tank and Caustic Addition Tank to the Containment Sump. The level did not reach the point where any components in the containment basement were affected.
-- Service Water flowed to the A and C Recirculation Spray Heat Exchangers.
-- Containment Instrument Air isolated.
-- Emergency Diesel Generator (EDG) No.2 started but did not load since its associated Emergency Bus remained energized by offsite power. The EDG was stopped and returned to automatic.

"A root cause evaluation is in progress."

The licensee notified the NRC Resident Inspector

NOTIFICATION OF UNUSUAL EVENT DUE TO TOXIC GAS IN RADWASTE CONTROL ROOM

"Entered an Unusual Event [under Emergency Action Level] MU1, toxic gas, carbon monoxide (CO), detected in the Radwaste Control Room. Levels rose to 34 ppm and the Radwaste Control Room was evacuated prior to reaching the First Energy exposure limit of 35 ppm. The source of the CO has not been determined. There is no radiation release from this event."

There were no personnel injuries and offsite assistance was not requested. There was no effect on plant operations. The licensee has notified state and local authorities and the NRC Resident Inspector.

Notified DHS SWO, FEMA, DHS NICC and NuclearSSA via email.

* * * UPDATE AT 1504 EST ON 11/28/12 FROM MARIKIO BLOUNT TO HUFFMAN * * *

" [At 1452 EST, the licensee] terminated the Unusual Event for MU1, due to toxic gas - carbon monoxide, detected in the Radwaste Control Room. The source of the carbon monoxide readings was determined to be from a leaking acetylene bottle. The acetylene bottle has been removed from the building. Carbon monoxide readings have returned to normal."

The licensee noted that the acetylene is detected as carbon monoxide by the toxic gas monitoring devices.

The licensee has notified State and local authorities and the NRC Resident Inspector.

Notified R3DO (Stone), NRR (EO) Lubinski) , IRD (Marshall), DHS SWO, FEMA, DHS NICC and NuclearSSA via email.