PLUTONIUM (Plutonium) — radionuclide with sequence number 94, belongs to actinides of transuranic group. 15 isotopes P. with mass number from 232 to 246, the majority of which are and - radiators, are known. In the nuclear equipment and power the greatest practical application has 239 Pu which is received in I the turf the reactor (see. nuclear reactors ). 239 Pu — an alpha emitter with half-life 2,44*10 4 years — has also soft x-ray emission and weak gamma radiation. The item constitutes danger at hit in an organism in the inhalation way, and also through skin (especially at its damage) and went. - kish. path. Acute action of P. is followed by damage of a bone tissue, aplastic changes of the hemopoietic bodies and a hemorrhagic syndrome; the remote effects of influence are the pneumosclerosis, osteosarcomas. Bodies of preferential accumulation of P.: lungs — for insoluble compounds, a bone — for soluble. Admissible concentration 239 Pu in air of workrooms 9,0*10 - 16 curie/l, in free air 3,0*10 - 17 curie/l, in water 2,2*10 - 9 curie/l. Admissible contents in lungs 0,008; in bones 0,02 mkkyur. For assessment of maintenance of P. in an organism use direct measurement of its x-ray emission (see. Dosimetry of ionizing radiation ), and also the indirect method based on analysis findings of excrement.
P.'s removal from an organism accelerates under influence Pentacinum (see). For deactivation of skin paste 116, the drug «Protection» and Dekontamin solution are used.
See also Actinoids .
Bibliography: Biological effect of external and internal sources of radiation, under the editorship of Yu. I. Moskalyov and V. S. Kalistra-tova, page 241, M., 1972; Acute management at acute radiation vozdeyst' viya, under the editorship of L. A. Ilyin, M., 1976; Standards of radiation safety (NRB — 76), M., 1978; The Remote effects of radiation injuries, under the editorship of Yu. I. Moskalyov, page 295, M., 1971; Cohen B. L. Plutonium toxicity, an evalu-tion indicates it is relatively harmless, Nucl. Engin. int., v. 21, No. 250, p. 35, 1976; V o e 1 z G. L. What we have learned about plutonium from human data, Hlth Phys., v. 29, p. 551, 1975.
G. M. Parkhomenko.