Re: Do CANDU reactors produce (net) nuclear waste?

On Apr 28, 9:20 am, "Giuseppe" <g...@xxxxxxxxxx> wrote:
"Alex Terrell" <alexterr...@xxxxxxxxx> ha scritto nel messaggionews:1177765474.341114.73660@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

I was looking up the CANDU reactor design.

There's a description at:http://en.wikipedia.org/wiki/CANDU

An interesting piece states:
"Recyling of LWR fuel does not necessarily need to involve a
reprocessing step. Fuel cycle tests have also included the DUPIC fuel
cycle, or direct use of spent PWR fuel in CANDU, where used fuel from
a pressurized water reactor is packaged into a CANDU fuel bundle with
only physical reprocessing (cut into pieces) but no chemical
reprocessing. Again, where light-water reactors require the reactivity

I don' understand how it's possible to recycle Lwr fuel rods with no
reprocessing,at least separation of uranium from neutron "poisons" fission
products; if criticality is still possible,it's however a great loss in
terms of energy "wasted"



associated with enriched fuel, the DUPIC fuel cycle is possible in a
CANDU reactor due to the neutron economy which allows for the low
reactivity of natural uranium and used enriched fuel."

In short, it seems that "waste" from a normal reactor can be used as
fuel for a CANDU reactor. What waste though does a CANDU reactor
produce?

Depending on what you mean by 'repreocessing'. Some CANDUs can be
'simply' engineered to take the LWR/PWR fuel rods by 'repackaging' the
pellets into the larger size rodes for the CANDUs.

If a CANDU reactor's waste is no worse than waste from a normal
reactor, then such a reactor would generate power without adding to
the waste problem.

Correct. About 25-30 tonnes of spent fuel or three cubic metres per
year of vitrified waste for a typical large nuclear reactor (1000 MWe,
light water type). This can be effectively and economically isolated
*in any event*. The CANDUs in the Advanced models are having their
cores 'shrunk', literally, by 30 to 50% from normal CANDUS with the
SAME power output but with a similiar shrinkage of high level
"wastes". Other CANDUs modifed can eat THIS waste with almost nothing
left.

David



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Relevant Pages

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