Fiber-optic cables that allow the Japan Nuclear Energy Safety Organization to monitor the Monju prototype fast-breeder reactor appear to have been damaged in a landslide Sept. 16 caused by powerful Typhoon No. 18, officials said.
Fiber-optic cables that allow the Japan Nuclear Energy Safety Organization to monitor the Monju prototype fast-breeder reactor appear to have been damaged in a landslide Sept. 16 caused by powerful Typhoon No. 18, officials said.
The Monju plant, based in Tsuruga, Fukui Prefecture, was already suspended before the typhoon, which killed three people and left more than 120 injured across the nation, made landfall.
The system sends reactor temperatures and pressure readings, as well as data from monitoring posts, to the Japan Nuclear Energy Safety Organization around the clock.
The Nuclear Regulation Authority and the prime minister’s office use the information to deal with accidents or problems.
The NRA secretariat told the operator, Japan Atomic Energy Agency, to monitor the data and report any problems directly because it will take more than a week before the fiber-optic cables are repaired.
The system was suspended at 2:55 a.m., and the NRA secretariat was notified at 3:45 a.m., officials said.
Workers in charge of inspections and repairs were unable to enter the reactor compound until around 2:30 p.m. because landslide debris blocked a road to the site. No other damage was reported.
The Monju sodium-cooled fast-breeder reactor has been mostly suspended since a sodium leak in December 1995.
In May, the NRA suspended preparations to resume operations after the operator was found to have neglected the inspection of nearly 10,000 pieces of equipment at the facility.