Reliance Power said boiler light up has been achieved for its fifth 660 MW unit at the 3,960-MW Sasan power plant in Madhya Pradesh. Boiler light up is a critical milestone of boiler commissioning activities for a unit. The first four of the six 660 MW units of the project are operational and the last unit is in the advanced stage of construction, RPower said. The Sasan project is an integrated power plant and coal mining project. Coal production has already commenced from the 20-million-tonne Moher and Moher-Amlohri coal mines associated with the power project.