Do Japanese authorities need to cool before dismantle

[cloa513]

I am thinking why not use mobile cranes to slowly prepare to remove fuel rods (vision from UAV or distant helicopters or balloons) (cutting using fibre lasers) and then remove and contain fuel rods. They already have a concrete truck reaching 44 metres to deliver water and the world longest reach crane is 100 m so the lengths to reach are within current technology. Most of crane's actions are mechanical so radiation is not a big issue and operator would be out of line of sight.

Is it just linear thinking on the nuclear authorities/industry or is absolutely necessary to get cooling to work permanently before considering dismantling?

 

[Astronuc]

Yes - for assemblies or collection of fuel rods. They are waiting to place the assemblies and collection of rods in more secure containment. The heat generation and radioactivity must be allowed to decay in order for current systems to be used for storage.

The other concern is decontamination of the water used to cool the spent fuel and fuel in the reactor. The radionuclides will have to be filtered and collected, and packaged securely for final disposal.

 

[cloa513]

Thank you for your reply. No reason that accessing the top of the plant should in any way (except sometimes less direct water flows for short periods) affect their other activities whether it be water management or cooling systems. The fuel rods may be very hot but for high temperature steels e.g. 1000 C is no big deal for short periods (specialty steels) and steel may be affected by the radiation but hardly likely over short periods. The fuel rods only need to put and contained in short term steel vessels long enough for more permanent vessels to made available.

 

[Astronuc]

Actually AREVA has a plan to process the radioactive water.

From AREVA's website - AREVA to set up a water decontamination process for the Fukushima site
http://www.areva.com/EN/news-8856/a...amination-process-for-the-fukushima-site.html

They need to decontaminate the cores and SFP to the extent possible, then the remove whatever fuel is intact, then remove the debris, then disassemble the primary systems, then disassemble the containment and secondary sides.