[ RadSafe ] Subduction Zones and Nuclear Waste

[George Stanford]

Joe:

      Here are some thoughts for your consideration.

      If the "nuclear waste" consists of used fuel
from thermal reactors, deep-sea disposal is indeed
a bad idea -- not because of the radioactivity,
but because only 5% of the fuel's energy (or much
less, in the case of HWRs) has been used, and it
would be expensive to try to retrieve it.  Much
better to put it in retrievable storage in Yucca
Mountain, so that its uranium and fissile material
(plutonium) will be available for when fast
reactors are to be started up (eventually doing
away with uranium mining for centuries, and with
milling, and enrichment of uranium forever).

      But it's a different kettle of fish if the
waste consists largely of unwanted fission
products (many of which have commercial value).
I'm not qualified to say whether you're right or
wrong about the subduction angle, but I'll point
out that it doesn't matter – for two reasons.
First, the waste, packaged in suitable containers,
can be dropped where it will bury itself in the
silt, where it will sit undisturbed for many
millennia, constituting less of an insult to the
biosphere than just about any other human activity
you care to name.

      Suppose, however, the waste were to start to
dissolve in the sea water almost immediately
(which it wouldn't).  Remember that the oceans are
already appreciably radioactive (K-40, mainly).
If you do the calculation, you find that, with
reasonable dispersal of the waste canisters, the
increment to the oceans' radioactivity would be
utterly inconsequential.

      Why is this not taken seriously?  Because
it's so cheap that there's no money to be made
from it, so there's no lobby for it.  The
opposition comes from an unholy alliance of
uninformed environmentalists and interests that
want to be paid for researching and developing
various expensive methods of land disposal.

      -- George Stanford
         Reactor physicist, retired.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

At 07:42 PM 10/21/2010, JPreisig at aol.com wrote (in
part):
Howdy Radsafe:

    One poster to radsafe or more keeps suggesting
we  put nuclear waste into subduction zones for
disposal (in the ocean) and the subduction/
convection cycle will carry the nuclear
waste down into the Earth and keep it there.  I
doubt that this would work.  The surface areas at
the entrance ways to subduction zones are usually
covered by layers of sediment (accretionary
wedges???) which would keep the waste from being
subducted.  The nuclear waste would just sit there
on top of the sediment layers without ever moving
downward.  Duh...

      Let's keep the nuclear waste up here on the
surface of the Earth, with no need to put nuclear
waste in the ocean.  Nuclear waste in the ocean
was an idea for the 1950's -- not very viable
today. I don't mind opening up Yucca Mountain at
all.  So what will happen in the November 2010
election -- eh, boys and girls.  If that
republican woman upsets Reid in Nevada, will the
Nuclear Waste trucks be headed to Yucca
Mountain??? . . .

     Regards,
    Joseph R. (Joe) Preisig, Ph.D.
    (not Joseph O. Preisig,
     formerly of RCA Princeton,
     Hightstown and Somerville, NJ  USA)