Major work required at Rokkasho for new regulations

Tuesday, 17 November 2015

Completion of Japan's Rokkasho reprocessing plant and mixed-oxide (MOX) fuel factory have been postponed by around two years as work continues to comply with new safety requirements.

An announcement from Japan Nuclear Fuels Ltd (JNFL) today explained that Rokkasho would be complete in mid-2018 rather than early 2016, while the MOX plant will be complete in mid-2019 instead of late 2017.

Together the facilities will store used nuclear fuel from Japanese nuclear power plants before separating it into one stream of waste for disposal and another stream of uranium and plutonium that would be recycled in new MOX fuel assemblies. This work has previously been carried out for Japanese power companies at similar facilities in France and the UK.

JNFL said the reprocessing plant needs a new emergency response centre twice as large as the one that was completed around the time of the Fukushima accident in 2011. Furthermore the new building will need to be anchored to the bedrock. Similarly, an existing water storage tank built before the new regulations came in must be retrofitted with anchors to secure it to the bedrock. In addition, a large amount of piping must be upgraded to higher seismic standards. All this work will take another 2.5 years for the reprocessing plant and 3.5 years for the MOX plant, JNFL said, based on the current rate of progress in agreeing changes with regulators.

Among other things, post-Fukushima regulations mean Rokkasho must be ready to withstand the effects of earthquakes five times bigger (magnitude 9.0 instead of magnitude 8.3) and oceanic earthquakes 1.5 times bigger (magnitude 7.4 instead of 7.2).

Nuclear power plants are also going through the process of satisfying regulators that they meet the new more stringent requirements. The first reactor, Sendai 1, restarted in August and is producing electricity. Another 25 units are in the regulatory queue.

Researched and written
by World Nuclear News