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

4.2 UNTREATED WASTE CHARACTERIZATION
4.9
The quantities and composition of the wastes generated at each step in the post-fission
LWR fuel cycle have been studied in detail. Quantities used in this Statement are based
upon actual practice for processes that have been demonstrated and upon technical judgments
for processes that have not yet been commercially demonstrated. The untreated initial
wastes, termed primary wastes, are identified, described, and classified as the first step
in defining the environmental impact of radioactive waste treatment. Additional details are
presented in DOE/ET-0028 (Section 3.3).
The primary wastes are processed to form treated wastes suitable for disposal. It is
anticipated that essentially all commercial wastes (on a Curie basis) or a large fraction
(on a volume basis) will receive treatment. Treated wastes are of two types: 1) gaseous
wastes that have been treated to reduce their activity levels so they can be released to the
environment without harm to man, and 2) wastes that have been converted to a stable form
suitable for disposal so that their radioactivity will remain confined and out of contact
with man's environment.
Secondary wastes are generated in the treatment of primary wastes and in the subsequent
handling of treated wastes. Secondary wastes are generated not only from initial waste pro-
cessing, but also from the storage, transportation, and isolation steps. In most cases, the
amount of secondary wastes is small in comparison to the amount of primary wastes; neverthe-
less, an assessment of the environmental impacts is not complete without including the
effects of the secondary wastes. Treated secondary wastes are included with the treated
primary wastes in Section 4.3.7.
Decommissioning wastes result from the operations employed to decommission retired
nuclear fuel cycle facilities. These wastes must also be included in a complete analysis
of the impacts of nuclear waste treatment; characterization of such wastes is presented in
Section 4.6.
Many methods of classifying radioactive wastes are in use, based on the kind of radio-
activity contained, the amount of radioactivity contained, the untreated physical form, the
treated physical form, etc. In this Statement, wastes have been classified into categories
based.on their treatment requirement; i.e., all wastes requiring a similar treatment are
included in the same category. The categories and a brief generic description of each are
given in Table 4.2.1. The first three waste categories are specific to certain fuel cycles.
Spent fuel as a waste is specific only to the once-through cycle, and high-level liquid
waste and fuel residue are specific only to the reprocessing cycle. The last four waste
categories listed in Table 4.2.1 are generated in almost every facility in which radioactive
materials are processed, treated, or handled. Thus, both primary and secondary wastes of
these categories are found throughout the LWR fuel cycles.
Radioactive wastes are also generally classified according to their content of transu-
ranic (TRU) radionuclides (i.e., radionuclides with atomic number greater than 92). Because
of the long half-lives and high radiotoxicity of some TRU nuclides, TRU wastes are