Gas sphase chemical reactions of fission products using the gas jet technique

摘要

The Gas Jet Facility at the Ford Nuclear Reactor was used to study the yields of volatile selenium and bromine fission products of ~(235)U using a semi-automatic batch solvent extraction technique. A carrier gas mixture of ethylene and pre-purified nitrogen was used to sweep the fission products from the target to the chemistry area for analysis. The resulting gamma-ray spectra of the heptane and water phases consisted of the nuclides of interest (~(84)Se, ~(85)Se, ~(86)Se and ~(86)Br, ~(87)Br, ~(88)Br), activation products, and neutron reactions iwth the Ge in the detectors. Calculated activities of the nuclides of interest indicated that selenium fractions in the heptane phase remained the same. These selenium values were used to resolve the bromine nuclide fractions, viz., directly from fission and from the beta-decay of selenium. The fractions of the three directly-formed bromine nuclides of interest in the aqueous phase was calculated to be 0.97 +- 0.04.