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

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zirconium fire. In this accident, 2 kg of irradiated zirconium are available for combus-
tion. The 70-yr accumulated dose to a maximum-exposed individual was estimated to be
1 x 10 -9 rem.
Failed equipment will be disassembled at both the MOX-FFP and the FRP. It is antici-
pated that during this operation equipment could tip over or be dropped by an overhead
crane. The primary hazard from these accidents is to plant workers. No offsite releases
will occur.
Combustible waste treatment technologies involve either packaging with no treatment,
or controlled air incineration followed by ash immobilization. Generally, the minimum
treatment processes did not have potential for other than minor accidents. Both minor and
moderate accidents were identified for controlled air incinerators. No credible severe
accidents were identified for the treatment of combustible wastes.
Minor accidents involving combustible wastes include minor ruptures in waste bags,
small fires and waste package spills. The consequences of the largest release from a minor
accident are a 70-yr accumulated dose to a maximum-exposed individual of 2 x 10 -4 rem.
Moderate accidents in the incineration operation include explosions and large fires.
The largest 70-yr accumulated dose from a moderate accident is 8 x 10 -5 rem to the maximum-
exposed individual.
Eight accidents were identified for the immobilization of wet wastes using the bitumen
process: six minor and two moderate. Similar accidents are also plausible for the cementa-
tion process.
Minor accidents that do not generate areosols were considered to have no release of
material beyond the processing cell area. Spillage of the treated waste product would be
contained in the cell. A bitumen fire will result in the largest minor accident release.
The impact of releases from this accident would be negligible.
The accident with the largest release, classified as a moderate accident, was a filter
failure concurrent with a bitumen fire. This accident is expected to occur about once every
300 years and result in a 70-yr accumulated dose to the maximum-exposed individual of
5 x 10 -7 rem.
There are two types of radioactive components in gaseous effluent streams. The first
is radioactive gases and volatilized radionuclides. These components are captured either
by adsorption beds or by cryogenic processing of the gas stream. The second is radioactive
particulates entrained in the gas flow. These particulates are captured by the use of
highly efficient filtration systems. Gas effluent air processing systems at the FRP may use
all of these processes. However, at the MOX-FFP, filtration is the only process employed
since particulates are the only significant materials in the off-gas effluent.
Minor and moderate accidents were identified for the treatment of gaseous waste streams.
No credible severe accidents could be identified. Minor accidents include plugged beds and
filters, minor leakage through processing equipment and failure of active system components