Tepco To Install Autocatalytic Recombiners At Kashiwazaki Kariwa

Tokyo Electric Power Company (Tepco) is to begin the installation of passive autocatalytic recombiners (PARs) in reactor buildings at two of the seven units at its Kashiwazaki Kariwa nuclear power plant.

The Japan Atomic Industrial Forum (JAIF) said Tepco would install the PARs at units 1 and 7, and that work is expected to be completed by the end of June 2013. Tepco plans to install 50 PARs at Unit 1 and 56 at Unit 7, JAIF said. The work is being carried out to counter the possible effects of core damage of the kind that happened at Tepco’s Fukushima-Daiichi nuclear plant in March 2011.

Following the earthquake and tsunami that struck the Fukushima-Daiichi plant, explosions occurred at units 1, 3 and 4. The explosions were “presumably caused” by hydrogen released from core damage, a Japanese government-appointed investigative committee said.

PARs are safety devices which work constantly to oxidize traces of hydrogen into water catalytically. They are not dependent on external power or operator intervention. Only two of Japan’s 50 commercial nuclear reactors – Ohi-3 and Ohi-4 – have restarted commercial operation following the Fukushima-Daiichi accident. The other 48 are still undergoing comprehensive safety assessments and back-fitting.

Areva said last year that it had won a contract to provide all 23 of Japan’s pressurised water reactors with PARs. Areva says it has installed the recombiners in more than 140 nuclear plants worldwide. No Japanese facilities currently have the equipment.