The Ministry of Economy, Trade and Industry decided Wednesday that the cost to nuclear plant operators of decommissioning reactors should be passed on to all electricity users in principle even after the electricity market is fully opened to newcomers in 2016.

The controversial scheme is aimed at making sure plant operators can recoup the massive expenses involved. Critics say the plan could undermine fair competition by compelling new entrants with no nuclear power generation to share the decommissioning burden.

The cost is expected to be included as part of the usage fee of power grids and will be charged by power transmission and distribution companies to be spun off from regional electric companies following the planned market opening.

METI is expected to revise a related ministerial ordinance by the end of March. But it will also consider whether to allow exceptions to the new scheme as some members of an expert panel oppose the system for favoring nuclear power.