Post-irradiation investigation techniques in metallurgical hot cells in the NRI

Metallographic methods are described used in the research of irradiated material as are mechanical tests (tensile strength measurements, bending measurements, hardness measurements, determination of transition temperature curves, etc.). Density represents an important criterion in the evaluation of radiation stability of uranium metal kernel of fuel elements. For density determination the elements are weighed in the air and in n-octanol. Roughness is measured by maximal height of unevenness by the imprint technique using the Schmalz microscope. The equipment of another 6 hot cells and 2 semi-hot cells with new instrumentation is recommended. (M.K.)