ČEZ faces problems at Czech Dukovany nuclear power plant

ČEZ is facing problems at the Dukovany nuclear power plant, with only Unit 4 operating since 17 September. The first three units are currently undergoing a reassessment of X-ray images of pipeline welds and repairs to poorly executed welds. The State Office for Nuclear Safety (SÚJB) reported this yesterday.

Units 2 and 3 of the Dukovany nuclear power plant were shut down on 17 September due to insufficient-quality X-ray images, which could not be used to demonstrate the condition of weld joints in the systems. The situation also affected Unit 1, where inspections were being carried out as part of a planned outage for fuel replacement that began at the end of August.

„ČEZ shut down the two units after consulting us. Had it not done so itself, we would have pushed for it,“ says Dana Drábová, chair of the State Office for Nuclear Safety.

According to plant director Miloš Štěpanovský, the review of the X-ray images was intended to provide assurance and a thorough assessment of the plant’s condition before submitting an application to extend the operation of the oldest, Unit 1, by another 10 years.

According to ČEZ’s original information, the forced outage was expected to last 2 to 3 weeks; it is now certain that it will be longer than estimated.

The plant’s most important parts are in order

Dukovany: The most serious problem concerns the feedwater piping of the steam generators.

Poor-quality X-ray images were identified mainly on piping used to measure process parameters in both the nuclear and non-nuclear parts of the plant. From a nuclear safety perspective, the most serious shortcomings are the poor-quality images and welds on the feedwater piping of the steam generators.

Despite the poorly executed images at Unit 4, ČEZ demonstrated the safety of its operation. The severity of the shortcomings is lower than at the other units.

ČEZ is currently informing the SÚJB about the progress of repeat X-ray inspections and repairs. Before the shut-down units are restarted, it will have to demonstrate that all shortcomings have been remedied.

Experts comment on ČEZ’s approach

„It is the result of long-neglected maintenance aimed at maximising profits. ČEZ should carry out inspections using its own employees. Outsourcing sensitive services such as technical inspections is a crime in the case of nuclear power plants,“ said former Temelín nuclear power plant director František Hezoučký.

ČEZ spokesperson Ladislav Kříž responded to this criticism:

„Inspection activities are carried out by plant employees. However, some activities are tied to outages, and it is common global practice for them to be carried out by suppliers for multiple operators, partly because they may have more experience.“

Drábová expressed dissatisfaction with ČEZ’s approach to the review of Unit 1 as part of its application to extend its operation. The necessary documents are reportedly being submitted late and in inadequate quality. According to Drábová, rather than being granted a licence, Unit 1 could be given a permit for one or two years, during which ČEZ would have to put everything in order.

„We take the criticism very seriously and are taking steps to remedy the situation. We believe that we have made enormous progress in recent months,“ Kříž said.