Results of the examinations of corrosion specimens exposed in the HRT are presented. Specimens examined included (1) core screen samples, (2) core specimen array No. 1, (3) blanket specimen array No. 2, (4) core solution line specimen arrays No. 103 and 103A, (5) blanket solution line specimen array No. 203. Complete information is still not available on all the specimens removed from the reactor, however, those data which have been accumulated are presented. These include corrosion rates, computed from specimen weight-changes, and results of chemical analyses of scales removed from the specimens or specimen holders. Also included in the report is a summary of the HRT operating schedule during exposure of the specimen and of the status of examinations for those specimens removed from the reactor prior to run 20.

Further calculations have been made to determine the desired radial fuel distribution in the HFIR and in the forthcoming HFIR critical experiment. In the process the design of the core was changed to include a 1-cm-thick annular space of water between the two nearly equally thick fuel annuli, a metal-to-water ratio in the fuel annuli of 1.0 (0.050 in. thick plates and coolant channels ) was specified, and the active length of the core was increased from 18 to 20 in. Results of the calculations indicated that the largest ratio of maximum meat thickness to minimum meat thickness occurred in the inner fuel annulus and was equal to 3.6, while the maximum fuel concentration occurred in the outer fuel annulus and was equivalent to about 0.7 g of U-235/cm^3 of meat. The total U-235 loading for this core was 8.01 kg, which results in a core lifetime of about 14 days.

A total of 104 thermal cycles between 250°F and 1350°F were imposed on a 3 1/2-in. and a 4-in. freeze flange to determine their susceptibility to thermal fatigue. The flange clamping arrangement was modified and various gaskets were used during the cycling in an effort to reduce the gas leakage problem.

The method of dispersion relations has in recent years found a wide application for the study of elementary particle reactions. Most of the work, however, deals with reactions of the type [formula], while the theory of those with more than two particles in the final state is still in a very preliminary stage. One reason for this is that even with only three particles in the final state the theory is already much more complicated. Nevertheless, a further development of the theory seemed to us very desirable. The theory at present is being developed on various levels simultaneously. Generally speaking, the aim of this paper is to put the theory in a form as closely as possible analogous to Mandelstam's formulation of the theory of reactions of type [formula]. In the later sections we specialize on reactions [formula], but as much as possible the formulation is in more general terms.

Quarterly report describing the progress and development of improved zirconium alloys for service in superheated water and steam. This report covers the period between October 1 to December 31, 1960 and was conducted by the United States and the European Atomic Energy Community (EURATOM).

From summary: This report describes the 10-watt Sr-90 thermoelectric generator, the dc-to-dc converter, batteries and the method of installation in the light buoy.