The nuclide Cs-137 is a fission product commonly used for measurement of uranium burnup in irradiated uranium fuel by the fission product to uranium ratio method. In the application of this method, the largest single error introduced in the measurement of burnup is the uncertainty in the half-life of Cs-137. Because of the uncertainty in this value and its importance in nuclear fuel burnup analysis, a reinvestigation was undertaken to obtain a more accurate value using the mass spectrometric method.

Test work was completed on development of a stripping method for the amine extraction (Amex) process which produces a concentrated uranyl nitrate solution for shipment to the refinery. This procedure offers potential cost savings by simplifying the overall mill-refinery flowsheet. The process involves treatment of the amine extract with calcium nitrate solution to convert the uranium in the solvent to a nitrate complex, stripping the uranium with water or dilute nitric acid, and recovery of nitrate from the solvent for recycle by contact with a lime slurry.

The development of swaging and vibratory compaction process for fabrication of clad UO2 fuel rods is described. The cost is less than 50% of that for an equivalent core fabricated from pellets. The irradiation testing of vibratory filled and swaged UO2 rods is reported for burn-ups from 2,000 to 12,000 Mwd/t UO2; the results indicate that the rods are capable of excellent performance power reactors.

"The quantum theory problem of constructing explicitly a local Lorentz invariant model field theory which has an asymptotic particle interpretation and gives rise to an S matrix different from unity is discussed. It is proved that if a local covariant field H(x) has a complete current, the S matrix associated with this field is identically equal to unity. Results show that in order to get an interaction, the current is not allowed to have a terminating expansion in terms of a free field. The absence of a finite connection between a free field and an interacting field tended to confirm the belief that in local quantum field theories with particle interpretation the requirement of the existence of scattering forces in the physical states are such that it is not pos sible to identify them with a linear space spanned by ""free'' particle states."

Abstract: A cyclic stress analysis of the SM-1 primary system was carried out. Problems encountered in the fabrication of PM-2A Core II and SM-lA Core II are described, and the results of an examination of damaged SM-lA Core I stationary fuel elements reported. A preliminary study of the radiation damage to SM-1 reactor vessel was made and the possibility of annealing the vessel discussed. Performance analyses are presented for five cores: SM-1 Core, SM-1 Core 1 rearranged and spiked, SM-1 Core II with special components, PM-2A Core 1, and SM- 1A Core 1. Preliminary critical experiments were made with SM-2 elements in a SM- 1 core configuration and nuclear and thermal analyses of the use of SM-2 elements in SM-1, SM-1A, and PM-2A completed. A throttling steam calorimeter was selected for measuring moisture carry-over on the PM-2A steam generator. Test procedures for evaluating the shielding of the SM-1, SM-lA, and PM-2A plants are summarized. Radiochemical and chemical analyses of SM-1 coolant and crud are summarized, and methods of activity control discussed. Preliminary results of studies of the properties of reactor pressure vessels under irradiation and no irradiation conditions are summarized briefly.

(p,xp) reactions are those nuclear reactions induced by high energy protons in which both the mans and the charge of the target nucleus are reduced by x-1 units. The most common type of these reactions to be expected in the 100 to 400 Mev region involves the exclusive emission of protons as a results of the interactions. The specific (p,xp) reactions investigated in this study were those where 2 is less than or equal to x where x is less than or equal to 5.