Post-Fukushima upgrades at Krško in Slovenia (www.nek.si) are being implemented in accordance with the requirements of the national regulator and the plant owners. The first phase, including a passive containment vent filtering system and hydrogen recombiners, a new emergency diesel generator, and a protected store of mobile emergency equipment, is already completed. The next phase in 2014-2018 will cover the emergency control room, a new technical support centre, reconstruction of an operation support centre, alternate cooling features for removing decay heat and on-site flood protection.
Generally speaking, radiation protection coverage is based on area monitors, airborne contamination monitors (installed or transportable) and routine or non-routine surveys performed by RP technicians.
The normal and post-accident (post-TMI) plant radiation and effluent monitoring system is relatively new. It was supplied by Merlin Gerin Provence (Mirion) and Sentry during an earlier upgrade, mainly based on the requirements of NRC RG 1.97. These monitors require an external power supply.
There are 11 normal area monitors (Mirion) in the nuclear island, three of them related to waste processing and storage. These monitors have local alarms as well as a main control room display and alarm modules. Their locations were defined by the Westinghouse plant design. After TMI, the monitoring system’s post-accident and normal-range channels were upgraded according to US regulations.