The manager of the Fukushima No. 1 nuclear plant admitted Thursday that some of the tanks built to store the radioactive water churned out each day are made with used parts but insisted their quality is fine for the purpose.
Earlier this week, it was reported that Tepco is using at least 20 tanks that were previously used at other construction sites, according to the daily Mainichi Shimbun.
Akira Ono, chief of the plant run by Tokyo Electric Power Co., said at a news conference that some of the flange-type tanks were built with used parts but insisted they were fit to hold tainted water.
Flange-type tanks are assembled with steel plates bolted together and sealed with waterproof packing at the seams. They are less water-tight than their welded counterparts.
Some of the tanks were built with used steel plates, but Tepco says it confirmed their soundness before reassembling the tanks at the meltdown-hit power plant.
Ono said the utility uses new parts to bind the old plates and to secure their seals, including the bolts and packing, and was confident this will not be an issue.
“As for flange-type tanks, I think it doesn’t really matter whether they are new or used,” as long as the plates themselves are healthy and the other parts are new, Ono said.
It is unclear how the high radiation or sustained exposure to sea water might be affecting the tanks.
Last August, about 300 tons of highly radioactive water leaked from a flange-type tank, but Ono said that tank had been built with all brand new parts, including the steel plates, and warned that even new tanks could leak.
There are more than 300 flange tanks dotting the subsidence-prone compound, and Tepco said it doesn’t know how many were built with used plates.
Because flange tanks are inherently leaky due to their many joints and seams, Tepco has been transferring tainted water to welded-type tanks when possible.