nuclear-news

TEPCO admitted Sunday it had dismissed earlier signs of water loss as within a margin of error and waited until a spike in radiation levels around the tanks was detected. Critics suspect cash-strapped TEPCO built poorly designed underground pits instead of safer and more manageable steel tanks to save money. TEPCO has also been criticized for delaying replacement of makeshift equipment, raising questions about whether the plant is really under control.

The underground tanks, several times the size of an Olympic swimming pool and similar to an industrial waste dump, are dug directly into the ground and protected by double-layer polyethylene linings inside an outermost clay-based lining, with a felt padding between each layer. Officials suspect there were ruptures in the linings due to the weight of the water.

Contaminated water at the plant, which suffered multiple meltdowns after the 2011 disaster, has escaped into the sea several times during the crisis. Experts suspect a continuous leak into the ocean through an underground water system, citing high levels of contamination in fish caught in waters just off the plant.

The contaminated water in the tanks is part of more than 270,000 tons of water used to cool melted fuel at the plant’s reactors damaged in the disaster. So much water has been used that TEPCO is struggling to find storage space. The water is also kept in hundreds of steel tanks.

NRA commissioner Toyoshi Fuketa told reporters Monday that the water leak poses a more immediate threat to the plant’s water management than to the environment. He questioned TEPCO’s risk evaluation in the tanks’ design process, but acknowledged that regulators have to allow TEPCO to use the remaining underground tanks for now.

“Although we need more long-term plans, we have to tackle the most immediate problem first. TEPCO’s decommissioning process is a tightrope situation to begin with,” he said. http://www.thestar.com/news/world/2013/04/08/japan_nuclear_safety_plans_too_lax_for_crowded_quakeprone_nation_say_nuclear_experts.html