To comply with Finnish nuclear regulation, Westinghouse and Siemens supplied equipment and engineering expertise.

This unorthodox mix of Western and Soviet enterprise led to the project developers being given the nickname "Eastinghouse".

[5] Fortum Power and Heat Oy applied to build a third reactor unit, to produce up to 1,000 MWth of district heating supply and from 800-1,600 MW of electrical generation, which the Finnish government declined on 21 April 2010.

[7] In 2014 Rolls-Royce took over the modernisation of safety-related systems for both units from an AREVA-Siemens consortium and the project was completed in 2018.

As part of the modernization works, turbine side upgrades will result in an extra 38 MW combined.