SALT-OCCLUDED ZEOLITES AS AN IMMOBILIZATION MATRIX FOR CHLORIDE WASTESALT

The pyrometallurgical processing of spent fuel from the integral fast reactor (IFR), an advanced reactor under development at Argonne Nation al Laboratory, will generate a chloride salt waste containing the alka li-metal, alka-line-earth, and some of the rare-earth fission products . Salt-occluded zeolite A, formed by equilibrating simulated molten wa ste salt and zeolite A, has been investigated as an immobilization mat rix for this salt waste. In this concept, the chloride waste salt is l oaded into the zeolite cavities, and cesium and strontium from the sal t are preferentially sorbed by the zeolite. Experiments showed that th e salt-occluded zeolite powders are leach resistant and radiation stab le. The conclusion is that the salt-occluded zeolite is a promising im mobilization matrix for the IFR waste salt.