Management of Commercially Generated Radioactive Waste - U.S. ...

4.26
Some partitioning options may be useful for maximizing energy conservation in the fuel
cycle, facilitating the beneficial use (Rohrmann 1968) of selected fission products, and
improving nuclear safeguards (Campbell and Gift 1978; Pobereskin, Kok and Madia 1977). The
recovery of cesium, for example, has been examined for use in sterilizing sewage sludges
(Sivinski 1975; Reynolds, Hagengruber and Zuppero 1974); strontium might also be used as a
heat source (Dix 1975) in remote and inacccessible areas. Partitioned palladium, rhodium,
ruthenium and technetium could become mineral resources.
On the other hand, partitioning will invariably complicate waste management during the
operation of the fuel cycle, as compared with other existing methods of dealing with the
unpartitioned wastes (ERDA-76-43, Section 16.2). Several reasons for this are:
* Increased production of secondary wastes. Althought the chemistry associated with
the partitioning of radionuclides is quite diverse, all known options generate
significant quantities of secondary wastes that must be managed. These secondary
wastes may be treated by incineration, by compaction, by immobilization, or by
other methods, but invariably the waste volumes will be increased by the parti-
tioning, and waste management costs will also increase. Many partitioning options
will significantly increase the high-level waste volume because of the addition
of salting agents or other nonvolative species. Also, many chemical additives may
adversely affect high-level waste solidification and the long-term stability of
the waste form (e.g., glass devitrification).
* Increased transportation costs and requirements. Most partitioned waste fractions
can be transported safely only with extensive shielding. For many of the transmu-
tation cycles, the transmutable elements are recycled many times before a signifi-
cant'reduction in quantity is achieved. In the case of actinides some of the
transmuted products are strong neutron emitters and will constitute a handling
problem. %
* Increased costs due to partitioning and secondary waste treatment. All known par-
titioning options involve sophisticated chemical separation processes that must
be remotely maintained and operated. Significant capital investment and operating
costs will result if these chemical processes are implemented. The recovery of
selected waste constituents, like cesium and strontium, does not significantly
reduce the cost of managing the residual high-level waste.
* Increased potential for radiation exposure. Since partitioning will require
increased chemical operations, handling, transportatior -,d storage, the poten-
tial for increased occupational radiation exposure also exists. The potential for
accidental release of radioactive material (and general population exposure) will
also be increased. These factors must be quantified if partitioning is adopted.
* Increased thermal loading. Partitioned waste fractions with high heat generation
densities impose a higher thermal load on containment materials than does unparti-
tioned waste. A recent study (NAS 1978) has suggested that the permanent contain-
ment of cesium and strontium partitioned from wastes at Hanford will be difficult
because of the high heat densities involved.