THE PURPOSE OF THIS PROGRAMME IS TO DETERMINE THE EFFECTS OF RADIATION ON THE PROPERTIES OF INTERMEDIATE LEVEL WASTE FORMS RELEVANT TO THEIR STORAGE AND DISPOSAL. IT HAS TWO OVERALL AIMS :
- TO PROVIDE IMMEDIATE DATA ON THE EFFECTS OF RADIATION ON IMPORTANT EUROPEAN ILW WASTE FORMS THROUGH ACCELERATED LABORATORY TESTS;
- TO DEVELOP AN UNDERSTANDING OF THE DEGRADATION PROCESSES SO THAT LONG-TERM, LOW DOSE RATE EFFECTS CAN BE PREDICTED WITH CONFIDENCE FROM SHORT-TERM, HIGH DOSE RATE EFEXPERIMENTS.
THE PROGRAMME WILL INCLUDE CEMENTED INORGANIC WASTE FORMS; ORGANIC MATRIX WASTE FORMS; AND CEMENT WASTE FORMS WITH A SUBSTANCIAL ORGANIC COMPONENT. IRRADIATION WILL BE CARRIED OUT BY EXTERNAL GAMMA SOURCES; BY THE INCORPORATION OF ALPHA EMITTERS. , SUCH AS 238 PU; AND, IF APPROPRIATE, BY MATRIX MATERIALS, SIMULATED WASTE FORMS AND REAL WASTE FORMS.
SPECIFIC TECHNICAL DATA WHICH WILL BE GENERATED WILL INCLUDE INFORMATION ON THE EFFECTS ON : MECHANICAL INTEGRITY; DIMENSIONAL STABILITY; GAS EVOLUTION; RADIONUCLIDE RELEASE, AND MICROSTRUCTURE. OTHER INFORMATION WHICH WILL BE GENERATED WILL INCLUDE MODELS AND PREDICTIVE METHODOLOGY FOR THE ASSESSMENT OF LONG-TERM BEHAVIOUR.
The study of the effects of radiation on the storage and disposal properties of intermediate level waste forms included cement waste forms containing a substantial component of organic waste. Irradiations were carried out using external gamma sources incorporating alpha emitters, such as plutonium-238. The irradiated materials also included matrix materials, simulated waste forms and real waste forms.
Irradiation of different types of conditioned ion exchangers produced a range of effects varying from total disintegration to only small changes in dimension.
Immobilised fuel hull residues remained in good physical condition with no measurable change up to a self radiation dose of 4 MGy.
B1. SELECTION AND PROCUREMENT OF SPECIMENS.
B2. GAMMA-DAMAGE EXPERIMENTS. MEASURE GAS EVOLUTION AND ABSORPTION. PROVIDE SPECIMENS FOR B4.
B3. ALPHA-DAMAGE EXPERIMENTS. MEASURE GAS EVOLUTION AND ABSORPTION. PROVIDE SPECIMENS FOR B4.
B4. ASSESS RADIATION DAMAGE. MONITOR DIMENSIONAL STABILITY, MECHANICAL INTEGRITY, MICROSTRUCTURAL CHANGES, LEACH RATES.
B5. IRRADIATION IN VENTED CONTAINERS.
B6. BASIC MECHANISMS. DEVELOP THEORETICAL MODELS. MEASURE ANY ADDITIONAL NECESSARY MATERIAL PROPERTIES.
B7. CONCLUSIONS AND FEEDBACK.