The operator of the Fukushima Daiichi nuclear power plant says it has become difficult to conduct another robot survey inside the containment vessel of one of the crippled reactors by March.
Tokyo Electric Power Company, or TEPCO, made the announcement on Thursday regarding the No.1 reactor, which experienced a meltdown due to the 2011 earthquake and tsunami. The utility says it will announce later when it will begin the survey.
TEPCO says the delay became necessary after workers faced setbacks during preparation for the survey.
The company says that when they were using high-pressure water to bore a hole in a door of the containment vessel, radioactive material that had piled up inside flew off.
TEPCO says the problem prompted a review of the procedure for the work, and no hole has been created yet.
TEPCO sent robot probes into the containment vessels of the No.2 and No.3 reactors and confirmed the existence of debris that is believed to contain molten nuclear fuel. The two reactors also experienced a meltdown.