Storage tanks for radiactive water too" flimsy"

December 26, 2012

Flimsy waste tanks cause new delay in Fukushima plant decontamination

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201212260032

THE ASAHI SHIMBUN

Tanks designed to hold radioactive filtrate at the Fukushima No. 1 nuclear plant are proving too fragile to be used, and the operator has announced a further delay in starting up machinery that cleans contaminated water.

Multinuclide removal equipment was originally slated to begin operation at the plant in September. But on Dec. 25, Tokyo Electric Power Co. said vessels that receive the machinery's radioactive discharge were failing drop tests and could not be relied upon.

Officials said reinforcing the tanks and testing them anew will take some time, so they are unable to predict when the equipment may finally come online.

The vessels are hoisted and lowered as they are filled and replaced by empty containers. In the event of an accident, they need to be strong enough to withstand a fall without releasing their radioactive contents.

TEPCO confirmed that the vessels could sustain a fall from a height of 6 meters in an upright position. But tests found the tanks were breaking and spilling their contents when dropped on from a height of only 3 meters in an upside-down position.

The findings were presented to a joint council on the mid- to long-term decommissioning of nuclear reactors, a body comprising government representatives and TEPCO officials.

The council decided that TEPCO should reinforce the vessel design and then hold more tests. TEPCO hopes to be ready to perform the tests in January.

Part of the multinuclide removal equipment to be installed at the Fukushima No. 1 nuclear plant. (Asahi Shimbun file photo)

TEPCO sees delay in new water treatment facility at Fukushima plant

http://mainichi.jp/english/english/newsselect/news/20121226p2g00m0dm022000c.html

TOKYO (Kyodo) -- Tokyo Electric Power Co. is seeing a delay in starting operation of a new water treatment facility that can remove more radioactive substances than the one currently being used at the crippled Fukushima Daiichi nuclear power plant, government officials said Tuesday.

The facility was expected to be introduced by the end of September as part of the utility's efforts to deal with a massive amount of contaminated water created as a result of continuing water injection into the damaged reactors.

But the utility still needs to check the strength of containers it plans to use to store radioactive waste generated through the water treatment process, the officials said following a meeting between the government and TEPCO to confirm progress toward decommissioning the reactors.

The utility plans to reinforce the containers so they can withstand the impact of possible accidents, such as a fall from a crane in transporting them. The officials did not elaborate on when they expect operation of the facility to actually start.

The current water processing facility has mainly worked to reduce the density of cesium, but the new facility can reduce that of about 60 types of radioactive substances such as strontium, the officials said.

Strontium tends to accumulate in bones and is feared to cause bone cancer and leukemia.

The water, after being cleaned, is recycled as a coolant for the three reactors which were crippled amid the nuclear crisis, triggered by the March 2011 massive earthquake and tsunami.