On 08/09/2016 11:40, The Natural Philosopher wrote:
On 08/09/16 10:19, Tim Watts wrote:
On 08/09/16 10:12, dennis@home wrote:
On 07/09/2016 09:47, The Natural Philosopher wrote:

The whole point of storing spent fuel rods in ponds is because fission
is going on.

Rubbish.
The stuff is stored in ponds while decay is going on.
If fission was going on the rods would never decay to the point where
they were safe to process.

While a few meters of water is enough to stop the decay radiation it
isn't going to stop the neutrons from killing the workers.

I suggest you look at the difference between decay and fission before
harry points it out.



TNP is quite correct - it's spontaneous fission:

https://en.wikipedia.org/wiki/Spontaneous_fission

Oh was that dennis? Wrong about everything as usual.

"Neutron radiation consists of a free neutron, usually emitted as a
result of spontaneous or induced nuclear fission. Able to travel
hundreds or even thousands of meters in air, they are however able to be
effectively stopped if blocked by a hydrogen-rich material, such as
concrete or water."

https://www.mirion.com/introduction-...ing-radiation/



The specific shield for neutrons is of course water, and a few meters is
precisely enough to stop them.

But in doing so it emits a ~2 MeV gamma ray which is pretty hard to stop.

Its somewhat more energetic than the gamma rays emitted by the decay
process.