Accumulation of trans-uranic elements and its application to 238Pu production in Japan

If transuranic elements are separated in fuel reprocessing, the separated elements are able to be directly the raw material for 238Pu production. Though the calculation of the demand for transuranic elements is difficult, the quantity required to produce cardiac pacemakers necessary in Japan is only 0.1% of the annual discharge in A.D.2000 of 237Np, a starting material for the production of 238Pu. Therefore, it is desirable to develop the way to utilize them safely and in large amounts. When 238Pu is used for cardiac pacemakers, it is required to minimize the leakage dose, and it is necessary to minimize the amount of mixing 236Pu and to remove light impurities by refining. Also in recovering 237Np and 241Am, specific facilities are required for radiation protection because of the works under high radiation level condition and the handling of long half-life α emitting substances. It is concluded from the above description, that progress in this field will not be resulted unless the steady practice of the plans based on long-range perspectives is performed. (Wakatsuki, Y.)