Link to the study - European Parliament - Europa

Policy Department D: Budgetary Affairs
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During decommissioning the so accumulated raw wastes have to be treated, packaged and later
disposed. Depending from the material several treatment methods are applicable:
Drying (for liquid or wet waste);
Compaction or super-compaction (for resins, filters, metal scrap or other materials);
Cutting (for metals);
Cementation (for metals);
Incineration (for combustible wastes).
For a brief overview on widely applied treatment methods (see WNA 2013). Treatment goals are:
volume reduction, limiting chemical gas generation, reducing microbial activity associated with gas
generation, immobilization (avoiding of losses of contaminated liquids or release of contaminated
dust particles) and inner-package corrosion prevention (e.g. drying).
Those technical methods are simple and robust. However, incompatibilities between the waste and a
potential matrix have to be avoided, e.g. cementation of evaporation wastes, resins or incineration
ashes due to chemical reactions of concrete with these materials.
Characteristics of plasma technology
A very special technology, rather expensive and very rarely applied is to heat the wastes in a plasma
oven to extremely high temperatures of several 1 000 C, so that carbon and organics are destroyed
and released as CO2. Metals are molten to yield metal and slag. The method was applied for
combustible conventional wastes, e.g. at Karlsruhe/Germany ('Thermoselect/Sinerga') with a typically
high energy input (electricity), high specific operating costs and technical difficulties, so that the
operation of the mentioned facility has been stopped by the operator. A facility for treating
operational LLW nuclear wastes at Würenlingen/Switzerland required enormous technical backfitting
to achieve the designed throughput. A pilot plant in the nuclear research center in Mol/Belgium was
operated in the 1980ies without positive results.
With nuclear wastes the high temperature of the plasma oven evaporates a considerable number of
radionuclides that are common constituents in operational wastes, such as Tritium (H-3, mainly as
tritiated water), Cesium-137 and Carbon-14. To limit doses received in the vicinity of the facility the
off-gas has to be cooled down and filtered (e.g. for Cesium-137). C-14 cannot be filtered without
enormous additional efforts (as it requires the removal of the complete carbon dioxide from the
discharged gas stream and its later disposal as radioactive waste) and so generating large quantities
of secondary wastes. Emitted C-14 dominates the doses in the vicinity of such plants by far and, due
to its long half-life time and its high mobility, circulates in the environment ('carbon cycle') and causes
high collective doses. The condensate from the off-gas cooling stage concentrates all evaporated
tritiated water and can have considerably higher concentrations (requiring additional treatment of
the condensate if it exceeds release criteria) (Nachtrodt 2013).
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