Current state of development of radioactivity standards

The range of radioactivity standards (according to UVVVR Catalogue of Standards) comprises 60 different radionuclides and is completed or changed as required by the needs of the national economy. The basic type is the ER Standard, the aqueous solution of a suitable chemical form of the radionuclide. Newly introduced standards called type EFS, are produced containing the radionuclides 57Co, 139Ce, 203Hg, 85Sr, 137Cs, 54Mn, 60Co, 88Y, 133Ba, 152Eu, 56Co. Other standards being introduced include carrier-free standard solutions of radionuclides, alpha, beta, X and gamma standard foils, standards of the gaseous forms of 3H, 85Kr, 131I, 133Xe, a set of large-area standards with 90(Sr+Y) and large-area standards of beta series radionuclides of high metrological value. (H.S.)