[ RadSafe ] NHK Report on Initial Removal of Fuel Rods from Fukushima Reactor #4 Cooling Pool

Mon Nov 25 10:59:04 CST 2013

I am not sure that it is reasonable to assume that the fuel in pools 1-3
melted.  I think it is safe to assume there was massive damage, what
with explosions, falling building bits, and no cooling, but depending on
how old the fuel was, it may not have been able to produce enough heat
to cause the cladding to break down.  In which case recovering those
fuel elements will be something of a technical challenge, and leaving
them where they are will complicate any activity on top of those
reactors, but the chances of that particular part of the situation
getting catastrophically worse seems small (at least compared to some of
the more readily available catastrophes they have available.  

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Roger Helbig
Sent: Friday, November 22, 2013 4:51 PM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] NHK Report on Initial Removal of Fuel Rods from
Fukushima Reactor #4 Cooling Pool

Thanks, Mike.  The #4 Pool was full because the reactor was shut down
Nov 30, 2010.  The others had very few elements in them so never made
the woe is me doom circuit.  I am sure that reports of the meltdown
include the numbers of fuel rods in each.

Roger Helbig

On Fri, Nov 22, 2013 at 9:25 AM, Brennan, Mike  (DOH)
<Mike.Brennan at doh.wa.gov> wrote:
> You are correct that the unused fuel does not need cooling.  I suspect

> there are a couple of reasons they are moving it to the storage pool:
>
> 1.  Practice.  These are low risk items, so getting a couple of 
> transfers under their belts where even if things go wrong they can't 
> really go horribly wrong is a good idea.
> 2.  Having been in the spent fuel pool it is possible that they are 
> contaminated.  If cladding on some of the actual spent fuel was 
> breached there is a possibility the unused fuel has surface 
> contamination.  Yes, it could be removed, but where and when would YOU

> want to do the survey and decon: on top of blown apart nuclear reactor

> building, beside a spent fuel pool, with winter coming on, or
practically anywhere else?
> 3.  Even though the fuel is unused, do you really see anyone letting 
> it into their reactor without close examination (and maybe even not
then)?
> So it has to go somewhere, and the paperwork is probably easier just 
> to move it with the spent fuel.
>
> As to how long spent fuel needs to cool before it can go into dry 
> cask; it depends on a number of factors.  Three years sounds a little 
> short to me, but I could be wrong.  I suspect that a lot of the fuel 
> in the pool can, should, and will wind up in dry cask, but I think 
> that is something to deal with after it is no longer up on a
compromised building.
>
> Something that I have wondered about is the state of the fuel pools on

> reactors 1-3.  I don't recall having heard anything about them.
>
> -----Original Message-----
> From: radsafe-bounces at health.phys.iit.edu
> [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Roger Helbig
> Sent: Friday, November 22, 2013 3:39 AM
> To: RADSAFE
> Subject: [ RadSafe ] NHK Report on Initial Removal of Fuel Rods from 
> Fukushima Reactor #4 Cooling Pool
>
> I am a bit confused on why fuel rods that have never been in the 
> reactor need to be stored in a cooling pool.  I also thought that 
> spent fuel rods that are nearing three years into the fission product 
> decay cycle would no longer need to be stored in a cooling pool, but 
> could be placed in more secure dry cask storage.
>
> Here is NHK report - that I found after watching another partial 
> report filtered through MOXNews linked to Christina MacPherson's 
> Nuclear-News's blog - the partial report crashed - perhaps due to my 
> own DSL modem failure (does anyone have a recommendation for a really
good DSL modem?
> - my Motorola one constantly overheats and I keep it cool with Blue 
> Ice
> block)
>
> Roger Helbig
>
> http://www3.nhk.or.jp/nhkworld/english/news/20131121_36.html
>
> "Cask" containing fuel moved into safer pool
>
> The operator of the Fukushima Daiichi power plant says it has removed 
> the first batch of nuclear fuel from the reactor 4 building to a safer

> storage pool.
>
> Footage released by Tokyo Electric Power Company on Thursday shows 
> workers lowering a steel cask containing 22 unused fuel assemblies 
> from the 5th floor of the reactor building. Engineers used a huge 
> crane to lower the cask, 5.5 meters long and two meters across, onto a

> trailer on the ground.
>
> The container was transferred slowly to a separate pool in a building
> 100 meters away, and lowered into water to store the fuel more safely.
>
> TEPCO plans to begin on Friday plucking the fuel assemblies out of the

> cask and placing them in storage racks inside the pool. The utility 
> says it will review the process before starting a second round of fuel

> transfer.
>
> Thursday's transfer involved unused fuel units. The reactor's storage 
> pool has 1,511 fuel assemblies left, including 1,331 highly 
> radioactive spent fuel assemblies.
>
> TEPCO says the building housing the separate pool can withstand an 
> earthquake as strong as the March 2011 disaster that badly damaged the

> plant.
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