Event Notification Report for December 07, 2018

INOPERABLE CONTROL ROOM ENVELOPE

"Braidwood Station was performing Control Room Envelope Testing. During testing the Station identified a failed acceptance criteria. The Control Room Envelope is a single train system and could constitute a Loss of Safety Function. If a single train system is inoperable per Technical Specifications (TS), it is Reportable as a Loss of Safety Function per 10 CFR 50.72(b)(3)(v) regardless of the system's continued ability to meet the accident analysis requirements.

"Both Units remain Mode 1, 100% power."

The licensee will be notifying the NRC Resident Inspector.

The acceptance criteria that failed was to maintain the control room pressure above the miscellaneous electrical equipment room pressure.

The station has realigned ventilation to normal, and has entered TS Limited Condition for Operation (LCO) 3.7.10 condition B, which requires the station to restore to operable the control room envelope within 90 days or shutdown the plant.

The station has also initiated contingency actions to verify SCBA (self contained breathing apparatus) are available and control room personnel are qualified to use SCBA.

* * * RETRACTION ON 12/20/18 AT 1714 EST FROM ANTHONY SIEBERT TO JEFFREY WHITED * * *

"On Wednesday, December 19, 2018, Braidwood Station concluded that the ENS notification 53784 could be retracted. It has been determined that the issue was not with the Control Room Envelope structure. Troubleshooting identified that the Unit 1 Upper Cable Spreading Room Area Supply Flow Control (OVC035Y) damper which supplies the Train A control room ventilation equipment room with air flow was not opening enough to supply the required flow. The subject duct work is shared by both A-train and B-train, and the flow through OVC035Y is controlled by a two-position actuator. The damper is less open when A-train is in operation (actuator energized) and more open when B-train is in operation (actuator de-energized). The only adjustments performed were to the actuator energized stroke limits which only affect the A train and thus a single train failure which could affect the safety function of both trains did not exist.

"Further calculations of unfiltered air inleakage into the Control Room Envelope (CRE) under a slightly negative differential pressure condition resulted in a calculated in leakage to the CRE of less than the maximum allowable unfiltered air inleakage for a radiological event of 436 scfm. The unfiltered air inleakage into the CRE assumed in the licensing basis analyses of Design Basis Accident consequences was never exceeded. Thus, TS Surveillance Requirement 3.7.10.4 continued to be met and entry into TS 3.7.10 Condition B was not required.

"The licensee has notified the NRC Resident Inspector."

Notified the R3DO (Stone).

AGREEMENT STATE REPORT - POTENTIAL OVEREXPOSURE

The following information was received from the State of Louisiana via email:

"[On 12/7/2018, the licensee's RSO reported to the Louisiana Department of Environmental Quality (LDEQ)] that his personnel monitoring provider had informed him of excessive exposures to a Nuclear Medicine Technologist's (NMT) monitors. The monitors had received a whole-body exposure of 6,358 mRem and an extremity exposure 29,245 mRem. The monitoring period was 9/20/20018 to 10/19/2018.

"[The RSO's] in-house investigation revealed he had a 'Reportable NMED Event'. The event occurred under the Ochsner Clinic Foundation Broad Scope Medical License (OCFBS), LA-0002-L01. The event involves two monitors, a whole-body and an extremity monitor. The monitoring company could not determine the type of exposure using their normal exposure filters.

"The RSO for this licensee did his own investigation after he was notified of the exposures on 12/5/2018. The RSO interviewed the NMT, reviewed area survey records, and did a bioassay of the NMT. The isotopes in use at the facility are Tc-99, Lu-177, and a Ga-68 generator. The NMT attaches both monitors together for storage after their use. The NMT did admit to not being in gloves at all times when handling radioactive isotopes. The RSO called in the possible NMED event [to the LDEQ] when he finished his investigation on 12/7/2018.

"This incident is being reported as a (potential) real or threatened excessive exposure NMED Event on 12/10/2018. The actual exposure determination will be up-dated when LDEQ concludes its investigation.

"LDEQ considers this incident still open and subject to investigation and corrective action implementation."

Event Report ID No.: LA-180020