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INVESTIGATION OF LLW AND MLW CEMENT PRODUCTS RESULTING FROM REPROCESSING

Objective

THE PROPOSED LABORATORY INVESTIGATIONS INCLUDE EXPERIMENTS WITH REAL SAMPLES FROM THE WASTE TREATMENT FACILITY AT KFK AND EXPERIMENTS WITH SIMULATED SAMPLES CONTAINING PU, AM AND NP.
WITH THESE SAMPLES DETAILED INVESTIGATIONS WILL BE PERFORMED TO DESCRIBE THE LONG TERM ACTIVITY RELEASE IN THE CASE OF LEACHING. THE EXPERIMENTS WILL BE PERFORMED AT ROOM TEMPERATURE USING WATER AND SALT BRINE AS LEACHANTS. THE AIM OF THE INVESTIGATIONS IS TO DETERMINE THE THERMODYNAMICALLY DEFINED EQUILIBRIUM CONCENTRATIONS OF PU, AM AND NP IN THE SYSTEM WASTE FORM/BRINE AS WELL THE LEACHING KINETICS. THE INVESTIGATIONS ON THE REAL SAMPLES WILL BE PERFORMED IN ORDER TO VARIFY THE NUMEROUS RESULTS FROM EXPERIMENTS ON SIMULATED SAMPLES.
The waste form studies served to determine the activities released from low and intermediate level cemented waste forms via the water path (leaching). The work performed concentrated on the behaviour of the actinide elements.

The majority of the investigations were performed on a laboratory scale with tracered samples (uranium, americium, plutonium, neptunium). In addition, laboratory experiments were carried out with real cemented waste forms in order to examine whether the results obtained with tracered samples can be transferred to real waste forms. A limited number of experiments were performed with inactive and active (real) full scale samples (200 litres). These investigations were carried out to determine the influence of the cementation process on the waste form properties.
B.1. INVESTIGATION WITH REAL SAMPLES. DETERMINATION OF THE KINETICS OF THE ACTIVITY RELEASE. DETERMINATION OF THE EQUILIBRIUM CONCENTRATIONS FOR PU, AM, NP, IN THE SYSTEM WASTE FORM/BRINE.

B.2. INVESTIGATIONS WITH SIMULATED SAMPLES. DETERMINATION OF THE KINETICS OF THE RELEASE OF PU, AM AND NP IN SALT BRINES. DETERMINATION OF EFFECTIVE DIFFUSION COEFFICIENTS FOR THE RELEASE FROM INTACT AND CORRODED SAMPLES.
DETERMINATION OF THE EQUILIBRIUM CONCENTRATIONS FOR PU, AM AND NP IN THE SYSTEM WASTE FORM-SALT BRINE.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

Forschungszentrum Karlsruhe Technik und Umwelt GmbH
Address

76021 Karlsruhe
Germany