Belgian outages rescheduled for concrete checks

18 June 2018

Belgium's nuclear power plant operator Electrabel has revised the timetable for scheduled maintenance outages at three of its reactors to check for degradation of concrete in the ceilings of buildings housing back-up safety-related equipment. The extended outages will cost the company some EUR250 million (USD290 million).

Tihange plant - 460 (Electrabel)
The Tihange plant (Image: Electrabel)

During a planned outage at Doel unit 3, which began in October, Electrabel discovered the concrete ceiling of a building adjacent to the reactor building required repair. This building contains "second level security systems, which are only used if there is a problem with the first level systems". The ceiling of the Doel 3 building - in rooms housing the outlet nozzles of the steam exhaust valves - is being repaired and the reactor is scheduled to restart on 1 August.

"Analyses have shown that in these installations, located in the non-nuclear part of the plant, the state of the concrete could be weakened as a result of hot and humid conditions," Electrabel's parent company Engie said. "Since the safety requirements foresee that the bunker buildings need to withstand an external event, the operator of the plant must be able to demonstrate that this resistance is ensured at all times."

In consultation with Belgium's Federal Agency for Nuclear Control (FANC), Electrabel has decided to revise the timetable for planned outages at Doel 4 and Tihange units 2 and 3 to inspect the ceilings of such buildings at those units.

At Tihange 3, a maintenance outage currently under way will be extended "by a few months" to September, FANC said. In April, Electrabel discovered a similar deterioration in the concrete of the ceiling of the rooms housing the outlet nozzles of the steam exhaust valves. It was concluded that this deterioration was caused by the release of steam during a specific test of one of the valves. Repairs to that ceiling are also under way.

FANC said inspections at Tihange 2 and Doel 4 will be made as soon as possible. The planned outage of Doel 4 will be brought forward from November to August, while the outage planned to start at Tihange 2 in August will be extended until the end of October.

"These dates have been set based on the information known today and could be adjusted depending on the results of the inspections and the work progress," Engie said.

"These revisions represent the equivalent of more than seven additional cumulative non-operating months in 2018 for an equivalent second generation unit (with a capacity of about 1 GWe), with no impact on 2019. The impact of these revisions is a shortfall of around EUR250 million in group EBITDA [earnings before interest, taxes, depreciation, and amortisation] and the group's share of net recurring income."

"At the latest, the first half financial results publication on 27 July, the Group will be able to clarify and comment in more detail the financial impact resulting from these measures," Engie said.

Researched and written
by World Nuclear News