With the Nuclear Regulation Authority (NRA) planning to redefine the meaning of ‘active fault’, Tokyo Electric Power Co. (TEPCO), the same operator of the disaster-stricken Fukushima nuclear power plant, might lose another of its plants. The Kashiwazaki Kariwa nuclear power plant could be permanently closed should the NRA decide that an active fault is one that has moved anytime in the last 400,000 years. Currently, the year limit is set at 120,000 to 130,000.
A couple of faults, known as alpha and beta, run directly under TEPCO’s No. 1 reactor at the largest nuclear power plant. It insists that neither fault lines moved for 120,000 to 240,000 years. Geological experts are not convinced. TEPCO has since then conducted another study to determine the date of the fault line movements, and results are set to be released next month. In the mean time, an NRA official said, “The new guidelines will be put into effect in July, and then we will re-evaluate the safety of each of Japan’s nuclear plants.”
In the new guidelines, vents that can filter out radioactive gases must be installed, mobile back-up electrical generators are to be readied, and there should be a set of criteria for use in evacuating areas around the power plants. It will also be mandatory that back-up control rooms be placed far away from reactor buildings to reduce the risk of plant workers irradiated when an emergency occurs. In order to be protected from potential terrorist attacks, protective barriers will also be required.