RE: DU from recycling?

["Stokes, James" <StokesJ@ttnus.com>]

 relative to the subject of Pu in Du:

Depleted uranium that was used as "target" material for Pu production
purposes, would not go back through the GDP once it was generated.  After
the PUREX process had recovered what Pu it could, the DU was in the form of
UO3.  That was the converted to UF4, then reduced to U-metal in a reduction
furnace, extruded as metal, and reformed into new target material.  There
would be trace quantities of Pu that would carry over in that process.

-----Original Message-----
From: Rodney Bauman
To: Multiple recipients of list
Sent: 1/31/01 10:14 AM
Subject: RE: DU from recycling?


Ruth and RadSafers:

"Recycled" uranium was also processed through the Oak Ridge GDP (i.e.,
the
K-25 site).  In fact, the very first shipment of "recycled" UO3 from
Hanford
in March of 1952 was shipped to K-25.

Franz: Yes the legacy uranium website, established to disseminate info
relevant to the recycled uranium issue, is currently inoperable.  Most
reports generated by the recycled uranium mass balance project are still
on
hold and may never be issued.  I can't help you there.

Much of the plutonium did not survive the fluorination process (i.e.,
UF4 to
UF6).  The plutonium (and some neptunium) concentrated in the ash
by-product
from the fluorination towers.  However, some of the transuranics did get
transferred with the UF6 into the transfer cylinders.  Upon cylinder
discharge into the cascades, the transuranics present quickly plated out
onto the internal surfaces of the transfer cylinders, feed piping and
diffusion barriers of the feed stages.

How did small quantities of transuranics make it into the depleted
stockpile?  Good question.  There may have been minute quantities that
made
it all the way through the gaseous diffusion process, however it is more
likely the result of cross-contamination activities, such as reusing
transfer cylinders for receiving/storing depleted UF6.

BTW, U-236 is going to physically act just like it is - uranium.
Although
it tended to concentrate more in the product (i.e., enriched) stream, a
smaller portion was extracted with the depleted stream.

Rodney Bauman, CHP, RRPT
rbauman@wssrap.com

-----Original Message-----
From: ruth_weiner [mailto:ruth_weiner@email.msn.com]
Sent: Tuesday, January 30, 2001 9:11 PM
To: Multiple recipients of list
Subject: Re: DU from recycling?


In partial response:  Some of the uranium that was enriched in the U.S.
enrichment facilities at Paducah and Portsmouth came from the plutonium
production reactors, so there are isotopes other than U-234, U-235, and
U-238 in the depeleted fraction from the enrichment plants when they
handled
that uranium.

On the question of plutonium hexafluoride: since the conversion to then
hexafluoride is done under highly oxidizing conditions, it seems to me
that
you would get stable Pu(VI);  it has certainly been produced in the LANL
and
LLNL laboratories (in lab quantities}.  Pu(V) is quite stable, and it
seems
to me the pentafluoride would also survive the fluoridation process.

Ruth Weiner
ruth_weiner@msn.com
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