Unit 6 of the Kozloduy nuclear plant will not load American fuel made by Westinghouse when it shuts down for refuelling in October. The reason is simple: the licence for the fuel is still being processed and just won't be ready in time, Elizabeth Tsvetanova, deputy head of Bulgaria's Nuclear Regulatory Agency, told reporters.

She said the agency got a request in April to licence six nuclear fuel assemblies made in Sweden. Staff have already checked the initial paperwork but asked for more information.

"We asked for more details on the monitoring programme for the assemblies during the time they'll be in use. We've now got that programme and are going through the documents. We'll probably bring in a consultant for part of this review," Tsvetanova said.

For now, unit 6 still runs on Russian nuclear fuel. Unit 5 already has Westinghouse fuel assemblies loaded, and the full switch to American fuel there should be finished by spring 2027.

Elizabeth Tsvetanova spoke to reporters at a seminar on keeping nuclear plants safe when the Danube river runs extremely low.