After the middle of May, the 5th unit of the Kozloduy NPP will be refueled with American Westinghouse nuclear fuel

After the middle of May, the 5th unit of the Kozloduy NPP is expected to be loaded with American nuclear fuel from the American company Westinghouse. "Plannedly, on May 4th we start reducing the power and on May 5th we expect to exit the system operator's parallel, and on May 7th scheduled repairs begin" (on the 5th power unit). This was said by Valentin Nikolov, the executive director of Kozloduy NPP, at a briefing at the Nuclear Regulatory Agency (NRA). "This day is very important for the diversification of Bulgaria," he pointed out.

Previously, NRA Executive Director Tsanko Bachiiski gave details on the process of licensing the American nuclear fuel. As is known, the nuclear regulator issued on April 22, 2024 permission for a phased transition to a new RWFA type nuclear fuel produced by Westinghouse.

"The licensing process lasted 9 months and was completed in full accordance with our internal program that we had developed in advance. Three things contributed to the timely completion of the review. Firstly, this is the fourth review we are doing of switching from one type of fuel to another, ie. we have sufficient experience and knowledge to make such a transition without undue delay. Second, we had very strong support from experienced experts from external organizations who helped us on topics important to the licensing process, and third, we were able to establish very good communication with Kozloduy NPP. We organized several meetings to present our observations and requests. As a result, new revisions were issued for 40 documents in order to complete the review as we had planned," said NRA Executive Director Tsanko Bachiiski.

"The review will begin in May with the loading of 43 cartridges in the active zone of the 5th unit of the Kozloduy NPP and will last for 4 years. During these 4 years, we will control the conditions we have set in the permit," he specified. After the current stage, there are two more active zone reloads.

With the transition of the 5th unit of the Kozloduy NPP to American nuclear fuel, the process of diversification has already really started, said the executive director of the nuclear power plant, Valentin Nikolov. He reminded that the process itself started back in 2019 with the signing of a contract with "Wessinghaus", it went through several important stages to reach the present moment. "Thanks to communications, thanks to the specialists who worked on this process, everything is now on time. During the entire period, we were the ones who also exercised control over the production process of assembling the nuclear fuel," said Nikolov. He reminded that despite the contract with Westinghouse for them to assemble it, there are two other companies - one engaged in the supply of uranium and the other in the enrichment to get to the process of full preparation for loading.

The fuel is currently stored under the conditions set by the NRA.

"You see how the geopolitical situation forced Bulgaria to look for other sources (of fuel for the NPP, for example). If we had not started in 2019 with the diversification, at some point the headquarters, given any sanctions or logistical problems, could have reached the point where we were looking for sources in emergency situations. We have a stock of fuel, but this case is indicative of how and how important diversification (of fuel) is for our nuclear power plant," said Nikolov.

The executive director of the Kozloduy NPP also gave details on the process of refueling the 6th unit with fuel of the French company Framatom, specifying that for the 6th unit fuel is provided until 2029. From this point of view, the complete diversification of the plant will be a reality by 2030.

However, at the moment, at Framatom's request, the fuel supply contract is being reviewed. The reason is that according to the contract with the French company, the fabrication of the fuel was supposed to be done in Linden, Germany, but since "a public consultation is required there on this matter, it caused them (Framatom) to delay and they requested a transfer from Framatom's German office to the French office. This is delaying the fuel deliveries a bit, but we are in the process of negotiations and there are things that need to be clarified in order to sign the contract again.

It is being specified when the French fuel should also arrive. In principle, this was supposed to be in 2025, but it may be delayed a bit. It won't be a problem for the plant because, as I said, we have fuel until 2029," said Nikolov. He clarified also that Kozloduy NPP is exploring the possibility of licensing American nuclear fuel to Westinghouse and for Unit 6 as security for a future point.

"When it will start, when it will end is another matter, but there are also such conversations going on." We had announced this anyway. A meeting was held with the NRA so that it could chart the path for this process. So we are looking for options to choose from, so that we don't stay with one supplier," Nikolov said.

The executive director of the nuclear power plant, in response to a question, specified that since the beginning of the war in Ukraine, there has been no removal of spent nuclear fuel and it is stored in designated areas on the site. At the same time, he pointed out that the nuclear fuel storage strategy aimed at this process is being delayed. Talks are also underway with EDF and Framatom about reprocessing.

Krasimir Kamenov, head of the "Nuclear Fuel" department at the Kozloduy NPP, for his part, reminded that the stages of diversification are listed in a special program that has been coordinated with the EU Supply Agency. He also gave details on the overall diversification process, the selection of the current cartridge type in December 2020, which was arrived at after relevant analyses. As Kamenov explained, the transfer of work to the 5th unit with Westinghouse RWFA type fuel also means an improvement in energy production and a reduction in the volume of fuel used. Cartridges, for example, instead of the current ones with Russian fuel 48 in number are fewer (43). Kamenov also reported details of the overall follow-up of the preparation of the fuel by the Bulgarian team of experts at the American company's plant in Sweden.

Both Valentin Nikolov, Krasimir Kamenov, and Tsanko Bachiyski, in response to a question about the concerns that are often associated with the failures years ago with American fuel at the Temelin NPP, explained that since 2010, significant improvements have been made to the cartridges themselves, of the structure itself. Seven units in Ukraine already operate with American nuclear fuel, they noted. "We have no worries. Our blocks are not experimental,” said the executive director of NRA.