Determination of the radiochemical yield of fission-fragment [sup.99]Mo IN VVR-Ts

The parameters of the neutron flux in the experimental channels of VVR-Ts are determined. It is shown that to evaluate the [sup.99]Mo yield it is necessary to take account of, aside from the neutron flux, the dependence of the fission cross section of [sup.235]U on the temperature of the neutron gas. The blocking coefficient is calculated for an experimental uranium target. The computed radiochemical yield of [sup.99]Mo is compared with the experimentally measured value. It is shown that the average yield equals 0.75. A correlation is found between the neutron flux density, which is directly proportional to the power of the VVR-Ts nuclear reactor, at the target location and the radiochemical yield of [sup.99]Mo.