The company carried out the work at Angra 1, a 657 MW pressurised water reactor plant owned by Eletrobrás Termonuclear (Eletronuclear).
MHI replaced the plant’s existing components with a new reactor vessel head and control rod drive mechanisms.
Angra 1 is about 130 kilometres west of Rio de Janeiro and began commercial operation in 1985.
Eletronuclear is a subsidiary of Centrais Eletricas Brasileiras, Brazil’s main electricity corporation, in which the government and Banco Central do Brasil, the country’s central bank, have a 60 per cent-plus stake.
Eletronuclear also owns and operates Angra 2 and is building Angra 3.