Westinghouse Electric has installed a fully passive containment filtered venting system (PCFVS) at the Nuklearna Elektrarna Krško nuclear power plant in Slovenia.

The upgrade to the nuclear plant will increase safety in the event of a severe nuclear accident.

The Slovenian Nuclear Safety Administration has made a compulsion of such upgrades following the March 2011 nuclear disaster at the Japanese Fukushima Daiichi power plant.

Installation of PCFVS was completed in 15 months, and the Krško plant is the first in Europe to set up a passive system for reducing the impact of a nuclear accident, Westinghouse said.

The venting system consists primarily of five aerosol filters inside containment, and an iodine filter inside the auxiliary building and various auxiliary components (such as valves and rupture disks) to ensure its fully passive operation during more than 72 hours.

Westinghouse said that the design and installation of the system allows the power plant to depend on a compact and modular dry metal fiber filter to capture the aerosols instead of using a large water tank.

This approach has allowed significant flexibility on where the filter can be installed, and at Krško, part of the filter was installed in the containment building.

"The upgrade to the nuclear plant will increase safety in the event of a severe nuclear accident."

The filters’ factory acceptance tests have positively surpassed levels required by regulatory authorities and by Krško.

PCFVS was installed for the components located inside auxiliary building, including the new plant stack anchored on the reactor building.

Installation of the equipment inside the reactor building, including closing of the containment penetration, did not impact the outage’s critical path.

Westinghouse vice-president and managing director southern Europe Javier González said that the customers clearly recognise the cost and technology advantage of its dry-filtered method of containment venting as the company is under contract for seven other units around the world.

"Since the design is modular, lead times can be much less than for other systems that require the construction of additional buildings," González said.