Fukushima: day 98

Dear Colleagues:

98th day!

I. Recapping on the water purification system
TEPCO announced suspension of the “integrated test” which combines all of the four units in series last night. A water leakage occurred in one of the molecular sieve sorption towers manufactured by the US Kurion, Inc. http://www.kurion.com/ which generated an automatic trip signal of leakage. TEPCO disassembled the tower and found that its rupture disk was burst due to an inadvertent closure of the stop valve to the next tower. Relevant photos are released at
http://www.tepco.co.jp/en/news/110311/index-e.html
Please download Rupture disk of cesium adsorption Instruments' vessel (Kurion)
By fixing the problem, the system resumed test at around 4 PM. TEPCO started the commissioning at 8:00 PM by using the real highly contaminated water. The operation of this system was indispensable to achieve recycling the injected water and preventing further increase in the total volume of the highly contaminated water. The purified water is going to be stored in a tank yard also shown in Temporary storage tanks (for treated water at Intermediate-and-low-level Radioactive Water Treatment Facility) (1) (pictured on June 5, 2011) and Temporary storage tanks (for treated water at Intermediate-and-low-level Radioactive Water Treatment Facility) (2) (pictured on June 5, 2011)
A schematics of this molecular sieve sorption stage is presented in ( http://www.tepco.co.jp/nu/fukushima-np/images/handouts_110617_03-j.pdf , in Japanese) English translation of the caption is from the left, the first stage is for removal of oil impregnate and technetium ( Surfactant Modified Zeolite ), the second stage is for removal of cesium ( herschelite / chabazite), followed with removal of iodine ( Ag impregnated herschelite ) as arranged in http://www.tepco.co.jp/nu/fukushima-np/images/handouts_110617_04-j.pdf

II. Recapping on removing contamination from 1F2 reactor building
It is amazing to find that all of Cs-134, Cs-137 and I-131 concentration in the air sampling from 1F2 sharply decreased since yesterday as shown in http://www.tepco.co.jp/nu/fukushima-np/images/handouts_110617_01-j.pdf
NISA gave a go sign to open the truck entrance door to the reactor building. TEPCO will try to get agreement with the local government for this operation.

III. Status of the "Roadmap towards Restoration from the Accident at Fukushima Daiichi Nuclear Power Station"
Details are posted in:
http://www.tepco.co.jp/en/press/corp-com/release/11061702-e.html

The new “Issue” 9, Radiation Control and Medical Care was added to improve environment for workers. Also, TEPCO is targeted to achieve stable cooling within a month to stop increase in the volume of the highly contaminated water.

Let me stop here today.

Genn Saji