[en] The testing of cemented waste specimens containing sodium nitrate and sodium sulphate has been carried out over a period of two and a half years. One set of samples is kept under environmental conditions which simulate the anticipated storage conditions and a second series is stored under water. Additional results are reported here from the long-term stability testing of these simulated cemented wastes. Some applications of the method developed for measuring the apparent viscosity of cement pastes are described. Some preliminary information is given on the assessment of cement-waste mixing equipment. (U.K.)