Event Notification Report for August 07, 2023

TROXLER MOISTURE DENSITY GAUGE INADVERTENTLY BUMPED BY TRUCK

The following summary information was provided by the licensee via telephone:

On 7/31/2023 at about 0730 MDT, employees of the City of Great Falls were standardizing a Troxler moisture density gauge (contained 9 millicuries of cesium-137 and 44 millicuries of americium-241) with the gauge on an asphalt lot and the source in its cage; as per standard practice. A loader truck inadvertently hit the gauge but was halted before it ran over the gauge. Some plastic on the gauge was damaged. The licensee halted operations and restricted access. Subsequently, radiation levels of 0.294 millirem per hour at 1 foot and 0.004 millirem per hour at 4 feet were measured, which were essentially background levels. No overexposure or other personnel injury were reported.

FAILED FITNESS FOR DUTY TEST

The following information was provided by the licensee via email:

A licensed employee had a confirmed positive for alcohol during a random fitness-for-duty test. The employee's access to the plant has been terminated.

The NRC Senior Resident Inspector was notified.

INITIAL PART 21 REPORT - DEFECT WITH EATON/CUTLER HAMMER SIZE 4 AND 5 FREEDOM SERIES CONTACTORS

The following information was provided by Paragon Energy Solutions, LLC via email:

"Pursuant to 10CFR 21.21(d)(3)(i), Paragon Energy Solutions, LLC is providing this initial notification of a potential defect with Eaton/Cutler Hammer size 4 and 5 freedom series contactors that have been modified to include either a special coil and/or to improve the securing of shading coils. These contactors may have been supplied integral to a motor control center (MCC) cubicle or as spare parts. This condition, if left uncorrected, could potentially cause a substantial safety hazard.

"Paragon completed an initial evaluation of a failure of a size 4 freedom series contactor (PN: NLI-CN15NN3A-T16-MOD-M) supplied to Perry Nuclear Power Plant. The reported failure occurred 26 days following installation into its associated MCC Cubicle. Perry identified the screws holding the contact bar to the push bars had fallen out and were laying in the bottom of the molded base. This allowed the movable contact bar to sit on the stationary contacts and significantly degrade due to arcing and then fail in the energized position. This condition could prevent the contactor from performing its safety function to either energize or de-energize the attached load.

"The loose hardware is most likely a workmanship error since the contactor must be disassembled to complete the special coil and RTV modifications to the shading coils. In the fully re-assembled condition, inspection of this hardware for tightness is not possible."

Affected plants: North Anna, Turkey Point, Harris, and Perry.

MANUAL REACTOR TRIP

The following information was provided by the licensee via email:

"At 1320 [EDT] on 08/04/2023, with the Unit 3 in Mode 1 at 100 percent power, the reactor was manually tripped due to lowering level in the 3C steam generator. The trip was uncomplicated with all systems responding normally post-trip.

"Decay heat is being removed via the auxiliary feed water system and the atmospheric steam dumps.

"Unit 4 is not affected.

"This event is being reported pursuant to 10 CFR 50.72(b)(2)(iv)(B), and 10 CFR 50.72(b)(3)(iv)(A). The NRC Resident Inspector has been notified."

The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:

The cause of lowering level in the 3C steam generator was unknown at the time of the notification and will be investigated by the licensee.

AUTOMATIC REACTOR TRIP

The following information was provided by the licensee via phone and email:

"At 1746 EDT on 08/04/2023, with Unit 2 in Mode 1 at 100 percent power, the reactor automatically tripped due to number 2 steam generator low low level. The trip was not complex, with all systems responding normally post-trip.

"Operations responded and stabilized the plant. Decay heat is being removed by using the auxiliary feedwater and steam dump systems. Unit 1 is not affected.

"Due to the reactor protection system actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). The expected actuation of the auxiliary feedwater system (an engineered safety feature) is being reported as an eight-hour report under 10 CFR 50.72 (b)(3)(iv)(A).

"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.

"All control rods are fully inserted. The cause of the number 2 steam generator low low level is being investigated."