Induced radionuclides in astronauts Final report, 15 Jun. 1967 - 1 Sep. 1968

Experimental determination of cosmic radiation effects on tissue equivalent materials and human

Cosmic ray induced radioactivity in astronauts as a measure of radiation dose /a/

Cosmic ray induced radioactivity in astronauts as measure of radiation dosag

In situ quantitative determination of transuranic elements in areas of high-level gamma radiation

A technique is described for passive neutron monitoring of transuranic elements. The method provides quantitative determinations of transuranic element concentrations in a variety of field situations where no other measurement method is possible. The technique can measure concentrations of transuranic oxides as low as 8 nCi/cm/sup 3/ and is capable of operating in gamma radiation fields up to megarads per hour. Information on chemical and isotopic composition can also be obtained from the data. Several successful applications of the technique are discussed

Environmental sampling and analysis as a safeguards tool

Environmental sampling and radionuclide analysis of the resulting material can be utilized as a supplemental approach in safeguarding practices and particularly for detection of undeclared nuclear activities. The production of nuclear weapons could be pursued by uranium enrichment processes to produce highly enriched U-235 or by nuclear reactor operations followed by chemical separations to produce Pu-239. The application of either of these processes results in the production of signature materials, some of which will be released to the environs. Results from the operations of the Hanford production facilities are discussed and indicate the type of signatures that may be expected from plutonium production facilities. These include noble gas emissions from the reactors and chemical separations processes, the production of radionuclides in reactor cooling water followed by their subsequent release to the Columbia River, and the release of mildly contaminated process water from the chemical processing facilities. These signature materials are carried by both gaseous and liqid effluents and enter various compartments of the environment. The types of signature materials which are most likely to be accumulated are discussed, together with examples of the quantities which have been released during past separations. There are numerous processes by which natural uranium may be enriched to produce highly enriched U-235. The most definitive signature of such processes is always a modification in uranium isotope ratios, and materials showing either enriched or depleted uranium in gaseous and liquid effluents provide the best indication that uramium enrichment processes are taking place. Therefore, techniques for sampling and analysis of airborne, waterborne, or deposited uranium in environmental matrices provide a means of detecting uranium enrichment which may lead to proliferation products

Instrument for determining the transuranic element content of chopped leached fuel hulls and other materials

An instrument has been designed, constructed, and evaluated for the identification and quantitative determination of transuranic elements by detection of neutrons emitted from their (..cap alpha.., n) and spontaneous fission reactions. Although optimized for batch evaluation of chopped leached nuclear fuel cladding hulls, the principle can be adapted to continuous feed operations. Unique electronic circuitry permits the sorting of neutron emissions depending on their origin which can be directly related to the isotopic composition of very small amounts of transuranic activities present in extreme gamma radiation fields. Efficiencies, sensitivities, and detection limits are discussed