Some deficiencies in analyzing leachates and reporting results

Determination of the leachability of elements from various waste forms for long-term retention of radioactive wastes requires chemical analysis of both the leachate and waste form for the various elements or radionuclides of interest. Neither the precision of the leaching procedure nor the accuracy of the results can be determined unambiguously if gross uncertainties exist in either the analytical methods used or the way in which the results are reported and/or interpreted. Perhaps the most important consideration is to demonstrate beforehand that all participating laboratories can obtain the same analytical result within some stated uncertainty when the same concentration is known to be present, i.e., by analysis of a single homogeneous solution. Special precautions must be taken to ensure that all material leached from the waste form is recovered from the leaching container and that all refractory particles are dissolved completely before analysis is begun. Problems involved in interlaboratory comparisons are also discussed