Sunday, January 5, 2014

Fukushima Nuclear Accident and Roadmap for Decommissioning

Kenji Tateiwa, TEPCO, nuclear power programs, Washington DC office

Worked at Fukushima Daini from 1996-2000 and lived in an area that is now uninhabitable.  Also worked on the advanced boiling water reactors of South Texas Project.
US nuclear industry had a team of 10 members in Tokyo for two years through INPO (Institute of Nuclear Power Operations).
Core meltdown in Unit 1
Have now identified the area of leakage in Unit 1
Spent fuel pools at Units 3 and 4
Biggest risk is the molten fuel in the cores, cooled by seawater which is leaking out and ground water is also flowing in.  No water is allowed to be dumped and all is stored on site. Thinking about building a frozen soil wall of about a mile to prevent groundwater inflow.
Seawater contamination only near the plants and offsite radiation has been reduced significantly.

Roadmap:  begin removal of spent fuel, removal of core melt - taking 10 years, decommissioning - taking 30-40 years
Integrated Management of Decommissioning Technologies - IRID established recently

He is extremely serious and committed and looks like he's hurting.  Somber.

Q:  How did TEPCO perform in informing the public?
Didn't hide anything but was perceived to have done so.  Hard to determine core melt although it is likely that three units have experienced it.  Experts never thought that the reactor building would have a hydrogen explosion.

Q:  Reform and breaking up the "nuclear village" with little regulation?
Nuclear safety reform plan from TEPCO issued 3/13 but plan is implemented by people and morale is now low.
Q:  Difficulties of decommissioning and what would it look like?
Cores may have melted to concrete floor outside pressure vessel, Unit 1 most severe.  Debris is mixture of materials from fuel and pressure vessel and needs to be cooled while being removed

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