Investing in Forsmark’s future

Work has been underway since June on the installation of independent core cooling for the three boiling water reactors at Forsmark, Sweden. The project is scheduled for completion by December 2020 and is being implemented such that
power production is not impaired.

The safety upgrade is required by the regulator, the Swedish Radiation Safety Authority, to enable continued power plant operation after 2020.

The decision to invest in the upgrade followed announcement that the nuclear capacity tax was to be phased out. The safety enhancement will be implemented in parallel with a programme of cost and efficiency improvements, with the goal of increasing competitiveness in the power market.

“Following this upgrade, the reactors will be able to generate electricity into the 2040s”, says Torbjörn Wahlborg, head of Vattenfall Generation and chairman of Forsmarks Kraftgrupp AB.

As part of the independent core cooling project, Sulzer will supply six diesel driven GSG barrel-type pump packages. These will supply coolant to the reactor vessels in an emergency and will not require any external power.

The GSG cooling water pumps will be produced by the Sulzer factory in Bruchsal, Germany. It is one of the few pump factories in the world that is equipped to simulate a “full string test” — including simulation of the plant’s system curve before the pumps are installed. The pumps, including the driving diesel engines, will be qualified for seismic resistance.

The need for independent core cooling has been on the Swedish regulator’s agenda for some years. The issue received increased attention after an event at Forsmark 1 on 25 July 2006 (loss of 400 kV supply followed by failure to connect of two out of four emergency diesel power supply systems), and became increasingly urgent after the Fukushima Daiichi accident in March 2011.

A corresponding decision to upgrade the Ringhals 3 and 4 pressurised water reactors is expected at the beginning of next year.