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Evaluation of a 4$pi$ neutron counter for the nondestructive analysis of uranium-234 in uranium hexafluoride

Description: A neutron counter has been evaluated for the nondestructive analysis of $sup 234$U in uranium hexafluoride. The instrument was designed by Los Alamos Scientific Laboratory for the Nuclear Safeguards Program. The method assumes that the only source of neutrons is from $sup 19$F($alpha$, n)$sup 22$Na reaction from $sup 238$U, $sup 235$U, and $sup 234$U, the yield from $sup 234$U being the most abundant. This evaluation shows that the mean of the difference between the 4 $pi$ neutron counting method and mass spectrometry is 0.0002 wt percent uranium- 234 +- 0.00015 at the 95 percent confidence level. However, the presence of $sup 232$U produces significant errors in the system. If the neutron technique is to be used for samples containing $sup 232$U in equilibrium with its daughters, the 2.61-MeV gamma peak of $sup 208$Tl must be measured and used to correct for the $sup 232$U. It has been postulated that the neutron counter might also be used to relate the $sup 234$U content of a sample to the $sup 235$U, thus estimating the $sup 235$U concentration. This evaluation notes, however, that in a variety of uranium feeds and enriched product, the $sup 234$U/$sup 235$U ratio varies too widely to enable a valid $sup 235$U determination.
Date: February 1, 1976
Creator: Mullins, W. T.
Partner: UNT Libraries Government Documents Department

Diffusion of Radioactive Gases Through Power Reactor Graphite

Description: Results of a study concerned with the problem of retarding the diffusion of fission products through unclad graphite fuel elements are presented. The pertinent parameters are pointed out, and their relations with the properties of graphite and gas coolants are considered. The effects of parameter variation on the concentration in the reactor primary system and the fission-product diffusion rate into the primary system are also examined. (J.R.D.)
Date: April 1, 1959
Creator: Weissberg, H. L. & Berman, A. S.
Partner: UNT Libraries Government Documents Department

A Fixed Filter Paper Alpha Air Monitor

Description: An instrument has been developed for the detection of uranium dust in the atmosphere. The principle feature of this device is its ability to indicate a gross release of alpha radiation within a few minutes of its occurrence. The unit will sound an alarm when either the indicated level or the rate of increase exceeds preset values above normal background variations. (auth)
Date: March 23, 1964
Creator: Seaborn, B. G.
Partner: UNT Libraries Government Documents Department