What has been the operating experience of the four ABWRs that have been in operation in Japan? It should be noted that performance is affected by Japanese utility operating strategies.

Compared with utilities elsewhere, they have had longer shutdowns for maintenance and refuelling, and shorter periods between refuelling outages. The UK has been taking a different approach, aiming to minimise periods when reactors are not generating. It will be for Horizon to decide whether to follow UK or Japanese precedent on that operating regime.