The loading operation for SM-1 Core II is described. Results of startup physics measurements (Test A-300 (Series) and fission product iodine monitoring in the primary coolant are given. The SM-1 Core II initial loading progressed satisfactorily, fulfilling the predictions of the zero power experiment performed at the Alco Criticality Facility. The initial cold clean five rod bank position was 6.53 in.; the initial hot, no xenon, five rod bank position was 9.62 in.; the initial hot, equilibrium xenon, five rod bank position was 11.41 in.; and the initial hot, peak xenon, five rod bank position was 12.14 in. Rods A and B were 19.00 in. in all four measurements. Stuck rod measurements indicated that an adequate shutdown margin was available with 20% of the rods fully withdrawn. All rod calibrations indicated a distinct shift and broadening of the peaks when compared with similar Core I calibrations. The temperature coefficient for Core II was 3.5 cents/ deg F at 440 deg F. Equilibrium xenon was worth approximately - 00 while peak xenon was worth - 43, both relative to the hot, no xenon core condition. During the period June 2, 1961 through September 30, 1961, the reactor operated at a total …

Gaseous waste handling systems are compared for direct and indirect boiling water and pressurized water reactors for PL-3 application. Areas that are common to the various concepts are not discussed since they do not enter into a comparison study. The major differences present are in the handling of active gases released to or held in the primary system coolant. These gases which could be present, their possibIe release from the system, and the necessary processing requirements are discussed in detail. Sufficient information is presented to enable one to analyze the methcds required to remove gaseous activity present in other size and type pressurized and boiIing water reactors. (auth)

Three types of frozen-seal valves'' were tested for possible use in the MSRE. The seal was melted by direct resistance heat, by induction heat, and by clamp-on Calrod heat. The frozen seal was made in a preformed restriction section of a standard piece of pipe by a cooling-gas jet stream directed at the restriction. All three valves performed satisfactorily through 100 test cycles. The Calrodheated valve was selected for MSRE use on the basis of simplicity of design and of operation. Two of the valves are successfully undergoing further tests on the MSRE Engineering Test Loop. (auth)

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