Skip to comments.Japan: TEPCO to directly pour water to No.3 reactor fuel (MOX fuel)
Posted on 08/23/2011 10:38:00 PM PDT by TigerLikesRooster
TEPCO to directly pour water to No.3 reactor fuel
Tokyo Electric Power Company will try a new process to cool down the No.3 reactor at the Fukushima Daiichi nuclear power plant by injecting water directly onto the facility's fuel starting on Friday.
The utility has been pouring 7 tons of water from outside the No.3 reactor every hour.
But this process has been producing a massive amount of high-level radioactive water.
TEPCO said on Monday that injecting cooling water through pipes situated above the fuel would be a more efficient operation.
The utility hopes this new process will reduce the amount of radioactive water produced.
The operator says it will check the effectiveness of the new system by monitoring the temperature levels.
Wednesday, August 24, 2011 07:04 +0900 (JST)
Between 1 a.m. and 3 a.m. on March 21, the pressure within the pressure vessel of the No. 3 reactor core increased sharply to about 110 atmospheres, likely caused by an explosion within the pressure vessel due to a lack of cooling of the fuel. That was probably the start of the second meltdown, Tanabe said.
The French core cooling water radioisotope removal system has proved inadequate because of entrained radioactive particulate loading, I hear. The French system appears to be a straightforward high temperature ion exchange resin system.
One could add a depth filtration step to remove particulates. Borosilicate glass fiber filling comes to mind.
One problem with filtration and ion exchange is that regeneration of resin releases the trapped radioisotopes into the environment so the filter and ion exchange components must be replaced after one use and treated as, in the Fukushima case, high level radwaste. A very expensive proposition.
A distillation process would be more practical in terms of cost but I don’t believe such a system is available in the practical sense at this time. There is a lot of radwaste in the Fukushima reactor systems, in the order of
exabecquerels (one followed by 18 zeros nuclear decays per second).
I see posts from folks much more qualified than I on your Fukushima posts. Perhaps they would care to enlarge on my comments (which I consider uninformed).
“The temperature of the reactor core of unit 3 of the damaged Fukushima Daiichi plant is expected to drop significantly with the commissioning of a more efficient cooling system, according to Tokyo Electric Power Company (Tepco)... “
“The central government on Aug. 25 lifted a ban on shipment of beef cattle from Fukushima, Iwate and Tochigi prefectures. “
“Shipments of early-harvested rice start in Fukushima Prefecture”
Daini plant restart preparation advances:
“ Investigation of reactor containment vessel of unit 4 and inside
At 10:15 am on 29th August, in order to investigate soundness of
reactor containment vessel of unit 4 and inside facilities, we have
opened airlock for site workers (hatch to enter into the primary
containment vessel), and we started investigation.
We are planning the same investigation of Unit 1 to 3.”