Monticello Nuclear Generating plant is making a voluntary report with regard to the
Technical Support Center (
TSC) not meeting design criteria Subsection 8.2-1.f of Supplement 1 to
NUREG-0737. This specifies that the
TSC will be provided with radiological protection necessary to assure that the radiation exposure to any person working in the
TSC would not exceed 5
REM whole body (or its equivalent part of the body) for the duration of the accident.
During review of the calculations associated with an on-going Alternative Source Term project, plant staff identified the potential for a radiation shine path to exist from the reactor building to the TSC during a DBA [Design Basis Accident] - Loss of Coolant Accident [LOCA], that could result in radiation levels reaching a point dictating evacuation of the TSC under existing emergency plan procedures.
As required by NUREG-0696 and confirmed by the plant staff, existing procedural guidance directs personnel to evacuate to the back-up TSC (located in the EOF) if the TSC cannot be occupied continuously.
The NRC resident has been informed of this discovery.'
The licensee is continuing their assessment and will determine the appropriate corrective actions.
