The Alco Products Criticality Facility, site location, and operating procedures are described in detail, including the handling of fissionable material and the operating procedures for the safe performance of critical experiments.

Abstract: The most adverse power distribution and power peaking factors have been developed for Type 3 replacement cores for SM-1, SM-1A, and PM-2A. Also included is the 37 element Type 3 core for SM-1, which is known as SM-1 Core III and is a prototype of a Type 3 core for PM-2A. The power distributions were compared with measured distributions obtained on type 3 fuel elements in SM-1, SM-1A and PM-2A core configurations. Using the measured data as a standard, correction factors were obtained and applied to the analytical predictions of the most adverse power distribution.

Preface; Subsequent to the analysis in the body of this report metallurgical developments indicated that it would not be feasible to build the APPR-1 Core II with the increased boron loading specified herein. At the time of the issuance of this report the Core II boron loading is to be the same as that for Core I. At the time of procurement of the core in the fall, if metallurgical developments warrant, the increased boron loading will be employed. The loading discussed in the body of the report and the first three appendices is that designed to meet the specifications outlined in the introduction. Appendix IV discusses changes in the loading to account for the various methods of employing boron.

Abstract: Hydrodynamic flow studies were conducted on a full scale model of the SM-2 reactor vessel and core. Test fluid was water at 200 psi and 200 degree F. Test facilities, model, and instrumentation design are discussed. Flow distribution in the stationary fuel elements, lattices, and control rods of the second pass was investigated. Pressure losses through the various core components were measured and are compared with calculated values. Observed over-all pressure drop was 71 feet of water at 200 degree F, 31% higher than predicted, part of which was due to presence of instrument leads. Element to element flow distribution varied approximately +-8% from pass average. Channel-to-channel stationary element flow distribution varied approximately +-10% from element average and control rod flow distribution varied from +-8.9% to +-6.4 and -11.6% depending upon rod locations. These variations exceed the original goals of a +-10% and +-12% combined deviation for stationary and control rod elements respectively, but are satisfactory in relation to thermal design. There was no indication of unsatisfactory structural performance of any components under hydrodynamic loadings up to 130% of design values. The test program was terminated after determining flow distribution in the reference core design, omitting any work on …