On 05/09/2013 11:28, GB wrote:
On 04/09/2013 21:08, The Natural Philosopher wrote:

You mean from this particular spill? Do you have figures for how many
of their experienced staff have had to stop work because of radiation
limits? Or are you saying it's just 2 since the original problems
started? If so, I must express my surprise.



As far as I know only two workers have been laid off because they had
reached teh 100mSV limit.

http://en.wikipedia.org/wiki/Fukushima_50

"Over 30 workers are radiated beyond 100 mSv by 23 April 2011."



Since the actual accident they wear suits when in higher level radiation
zones. Why would they not? They have also used robots.

I think they are only wearing paper overalls and particulate masks. The
idea is to protect against ingesting/breathing in radioactive particle.

Pretty much anything protects against beta radiation when it is outside
the body. The beta radiation risk is from radioactive particles inside.
That's why plutonium is so serious, IIRC.

Beta radiation is high energy electrons and can penetrate a few mm of
metal, paper overalls offers no protect from them.

Alpha particles are high energy helium nuclei and are stopped by much
thinner things.

Both may have associated gamma radiation which needs lead or a lot of
mass to stop.

The most dangerous, because its hard to stop, is probably neutrons but
they are a fission product and stop when the control rods are inserted.


The suits won't protect against gamma radiation and they provide no
effective defence against alpha radiation. (This is all me dredging this
info up from my school/university days, 40 years ago, so please excuse
any hopefully minor inaccuracies.)

No minor ones. ;-)



The main reason for not wanting to work on the site is that they don't
seem to be managing the place terribly well.