Japan’s Nuclear Regulation Authority (NRA) says it will suspend screening for restarts of reactors 6 and 7 at Tokyo Electric Power Co’s Kashiwazaki-kariwa NPP in Niigata Prefecture. NRA said Tepco must supply more data for a new method of assessing quake resistance of facilities and buildings. The two units have boiling-water reactors (BWRs), like those of the damaged Fukushima Daiichi plant. The screening had focused on measures to prevent serious accidents, as NRA had judged that the two units were of a new design and posed fewer safety risks. The screening was in the final stage, and had progressed further than for any other BWRs. However, NRA says that while the screening is suspended, it will resume screening of other BWRs, noting that assessing the quake resistance of units 6 and 7 may take another six months. Earlier in March, Tepco reported problems at Kashiwazaki-Kariwa unit 5 when a control rod in the offline reactor moved unexpectedly. Tepco officials said an alarm indicated that one of the reactor’s 185 control rods moved out of its normal position while workers were manipulating valves related to the control rods as part of regular inspections The rod reportedly returned to its normal position after about a minute.
