Vattenfall prepares for shutdown of Ringhals units

Vattenfall is preparing for the decommissioning of units 1 and 2 of the Ringhals nuclear power plant in Sweden. The company - which owns a majority stake in the plant - announced its intention in late April to close the two units by 2020.

Vattenfall is preparing for the decommissioning of units 1 and 2 of the Ringhals nuclear power plant in Sweden. The company - which owns a majority stake in the plant - announced its intention in late April to close the two units by 2020.

Ringhals units 1 and 2 (Image: Vattenfall)

Vattenfall - which owns a 70.4% stake in the Ringhals plant - said in April that it had informed co-owner EOn (holder of the remaining 29.6%) of its decision to close the units between 2018 and 2020, earlier than previously planned. The company said that the final decision to decommission the reactors early has yet to be made by the board of directors of the Ringhals plant and requires the agreement of EOn.

Immediately after informing EOn of its decision, Vattenfall initiated the STURE (Safe and Secure Phaseout of Reactors 1 and 2) project to pave the way for decommissioning the units. The project will coordinate all aspects of the preparations for the shutdown of the reactors.

STURE project leader Lars Björnkvist said, "It's not just a matter of shutting the reactors down. Doing it in the best and most efficient way requires a great deal of planning and documentation."

There are four main areas to the STURE project: staffing and culture, plant, financial optimization and permits.

Björnkvist said, "We must make sure we have the skills to operate the plants until the day they are shut down." He added, "We have to keep track of the skills that will be required in the units concerned, but also of how we stand generally at Ringhals in terms of the skills that are needed and the number of people retiring, etc."

While units Ringhals units 1 and 2 are set to close, units 3 and 4 will continue operating. Safety culture must be maintained in all phases of operation at the plant, Björnkvist stressed.

He also said that before the units can be shut down, an environmental impact assessment must be carried out. Planning permission will also be required for various temporary buildings.

STURE will also investigate the most cost-effective way of shutting down the reactors. "We'll consider all aspects, including the investments required and fuel management, in order to establish when and in what order the reactors should be decommissioned. Doing things in the most efficient way can save a fair amount of money," Björnkvist said.

While Ringhals AB is responsible for operating the plant on behalf of its owners, Vattenfall will be responsible for its decommissioning. Once the units enter shutdown mode, Vattenfall's decommissioning organization takes over.

"Clearly we'll work together and synchronize any action we take, and we'll collaborate over resources, in particular," Björnkvist noted.

Ringhals unit 1 is an 878 MWe boiling water reactor (BWR) which started operating in 1976 and had been due to be closed in 2026, while unit 2 is an 807 MWe pressurized water reactor (PWR) that began operation in 1975 and scheduled to shut down in 2025. Ringhals 3 and 4 are larger PWRs that started up in the early 1980s.

Researched and written
by World Nuclear News