Christian Lattaud and Yves Hery
Atomic Energy Commission

The purpose of this facility is to reduce the a activity level of the radwastes below the current acceptance standards set by ANDRA for its radwaste surface-disposal sites.

TRIRAD is an assembly of 16 glove-boxes set in two cubicles. The first cubicle (TRI) houses the portion dedicated to sorting and selection of radwastes, depending on their physico-chemical nature and a-contamination level. The second cubicle (RAD) houses the automatic decontamination system involving radwaste soaking in a cavitating solvent bath. Provision is made for additional decontamination, if need be, by high-pressure solvent spraying (250 bars).

Six g spectrometers ensure the measurements required for determining the decontamination factors, and real-time follow-up of the quantities of actinides present throughout the facility.

The results of a 5-year operation are shown in the diagram below.

• 88% of the radwastes generated are suitable for disposal to the radwaste surface-disposal sites of ANDRA;
• 4.3% of the radwastes generated are sent to interim storage at Cadarache Centre ;
• 6% of the incinerable radwastes will be processed in the a incinerator at VALDUC Centre.
• 1.7% only of the radwastes generated in TRIRAD are stored at VALDUC Centre, pending processing.

The average decontamination factor is 10 for the RAD cubicle with an average swell coefficient of 1.42 (radwaste output volume/radwaste input volume).

TRIRAD facility therefor meets its initial objective of processing an old stock of a -waste drums (approx. 1,200 drums of 200 litres).

The major problem encountered is the corrosion of the distillation and evaporation vat due to the degradation of solvent, at the level of the electrical heating elements. The heating is now obtained by means of a water exchanger at 60°C.

Taking account of investment ($2 millions) and working expenses ($250.000 per year), TRIRAD is a very effective and economical facility to reduce the volume of wastes sent to deep-geologic waste disposal site (estimated cost: $85.000/m³).

The radwastes, which cannot be evacuated to the ANDRA radwaste disposal sites nor be incinerated represent about 6% ot the product volume. The systematic utilization of high-pressure solvent spraying on this kind of radwastes ought to improve the efficiency of decontamination, and makes it possible to evacuate them to the ANDRA radwaste disposal sites.

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