TOKYO - Japan's Nuclear Regulation Authority (NRA) blasted Tokyo Electric Power Co. Wednesday for its inappropriate handling of fuel rods at its Kashiwazaki-Kariwa plant in Niigata Prefecture which caused some of the highly volatile rods to be damaged.
The NRA said that workers at the plant had tried forcibly to jam the rods into fuel assemblies when they wouldn't fit, leaving some 26 fuel assemblies with "abnormalities."
NRA Chairman Shunichi Tanaka stated that the safety culture at TEPCO has "serious problems," adding that the fuel handling problems could only be seen from inside the utility.
The nuclear regulator added that some of the rods were actually found to be touching each other in the assemblies and that the NRA was not made aware of the problem until 2012.
Initially the NRA considered the danger to be a Level 1 accident on a scale of 8, but on further investigation downgraded its assessment of the danger from being an "anomaly."
By comparison the March 2011 tsunami-triggered multiple meltdowns at the accident-prone utility's Fukushima Daiichi plant were judged to be a Level 7 accident, according to the NRA's judgments.
The NRA found that workers at the plant had been mishandling the fuel rods and the assemblies at least until 1998, when procedures were changed.
On Tuesday, TEPCO said of its stricken Daiichi nuclear power plant in Fukushima prefecture that cooling operations were stopped at its No. 4 reactor unit's spent fuel pool, due to workers damaging an electrical cable.
TEPCO said that workers damaged the cable while they were drilling near electrical equipment, causing an alert and the shut down of cooling operations at the No. 4 spent fuel pool, as well as the halting of an ongoing operation to remove hundreds of spent nuclear fuel rods from the pool.
The operator of the plant also said Tuesday a fire was triggered by the damage to the cable, although workers were able to extinguish this, the utility said.
Though the Japanese government on Jan. 15 announced injecting 4 trillion yen (38.3 billion U.S. dollars) in additional state backing to help the ailing utility deal with a string of mishaps at its facilities as it works towards decommissioning its stricken, yet volatile reactors, the problems continue, much to the consternation of Tanaka.
On Feb. 13. samples of water TEPCO tested contained radioactive cesium at records not seen at the Fukushima plant since the 2011 disaster.
The operator said there was a new leak at the site of a well located just 50 meters from the adjacent Pacific Ocean and confirmed that the levels of cesium found in its groundwater samples were as high as 54,000 becquerels per liter of cesium 137, and 22,000 becquerels per liter of cesium 134.
The levels of cesium detected were 600 times higher than the government regulation for contaminated wastewater allowed to be released into the ocean, with the samples testing 30,000 times higher for cesium 137, compared to samples taken just a week earlier.
As the utility was rebuked by domestic and international nuclear regulators and the wider international community for once again falsely measuring radiation levels, Tanaka lambasted TEPCO.
"Something like this cannot happen. This data is what becomes the basis of various decisions, so they must do their utmost to avoid mistakes in measuring radiation," Tanaka told a news conference, after the latest gaffe came to light.
TEPCO, despite its ongoing safety problems as highlighted by Tanaka Wednesday, plans to re-start the Kashiwazaki-Kariwa plant, its biggest nuclear facility, this summer, much to the dismay and concern of the local and international community who believe more stringent tests need to be conducted.
As for the stricken Fukushima complex, the beleaguered utility is still eyeing dumping radioactive water into the Pacific Ocean as it fails to contain it in makeshift storage tanks -- the source of a number of previous radioactive leaks.
Nuclear experts believe that the overall decommissioning of the earthquake and tsunami battered plant in Japan's northeast is expected to take around 40 years, with the removal of all nuclear fuel from the No. 4 reactor building being completed by the end of this year.
TEPCO has stated, however, that it had only successfully removed around 9 percent of more than 1,500 unused and spent fuel assemblies in the wrecked reactor building's storage pool.