Preface: The intermediate heat exchanger is designed for operation in a nuclear power plant using liquid sodium as the primary and secondary coolant. Since the primary fluid coming from the reactor is radioactive, the purpose of the IHX is to transfer heat to a nonradioactive fluid which then goes to a steam generator. Because of this activity the until will be enclosed in a concrete pit and will not be accessible during periods of operation. Immediately after shut down it will be necessary to allow time for radioactive decay before the unit will be accessible to personnel. Because of inaccessibility and possible long periods allowed for decay time, it is imperative that the unit give trouble free operation. During periods of shut down, the internals should have easy access for inspection and repair if necessary so that down time is held to a minimum. The general arrangement of the heat exchanger described in this report presents a conventional design utilizing known materials and existing methods of fabrication. In further consideration of all concepts, designs and analyses developed during this period of the program, it is felt that this preliminary design will provide an intermediate sodium heat exchanger of lower cost …

Abstract: The caustic permanganate-rinse decontamination treatment was investigated. Loop and metallurgical studies were performed to determine optimum operating conditions as well as the metallurgical effects of the treatment. A treatment with 10 percent sodium hydroxide and 5 percent potassium permanganate solution followed by a rinse with a 5 percent ammonium citrate, 2 percent citric acid and 1/2 percent Versene solution was chosen for the decontamination of a stainless steel steam generator. Decontamination factors of greater than 50 were obtained in loop tests using the above treatment. Corrosion and metallurgical results indicated a total penetration of less than 0.01 mil on annealed Type 304 stainless steel with no evidence of any deleterious effects.

Abstract: A survey of the problem of reactor system contamination by radioactive material and methods that have been employed to remove the material was carried out. Following this survey, an investigation of chemical solutions was undertaken to find one which might be successfully employed in the decontamination of a stainless steel steam generator. From a preliminary screening, the most promising chemical method from the view point of minimum corrosion and maximum decontamination is a caustic permanganate treatment followed by and acid rinse.

Abstract: A decontamination procedure for a stainless steel steam generator similar to the APPR-1 using a fill-flush application of a caustic permanganate-citrate combination solution is recommended. The isolation of the steam generator is to be accomplished by means of specially designed plugs at the reactor vessel outlet and at the primary coolant pumps. Anticipated results, including corrosion rates and decontamination factors, are presented.

Abstract: The primary coolant of the SM-1 (APPR-1) was analyzed for short-lived and fission product activities. Manganese-56 was found to be the predominant non-fission product nuclide contributing to the short lived activity. Fission products were found in the coolant. It is concluded these fission products originate from a defects in the cladding and from surface contamination of the fuel elements.

Introduction: Seldom does the actual arrangement of control elements in a nuclear reactor confers to the ideal and convenient mathematical array. In order to achieve shim control. safety and regulation, it is desirable to design with rods of different sizes and materials. With given fuel element arrangement, typically in square or hexagonal lattice spacing, there will be rods located at different distances form the center of the core and from each other. As the reactor operates, absorbers will be withdrawn, leaving further asymmetries in the location of those remaining. It is the purpose of this report to develop in detail a two-group diffusion theory with as complete generality as possible. The method is as yet restricted to the unreflected core, or to the reflected core by use of reflector savings and bare equivalent geometries.

Abstract: Fission product measurements were made on the SM-1 primary coolant. The airborne activity observed during the sampling of the primary system was identified. An analysis was made on the primary coolant for alpha activity and on the secondary water for fission production iodine.

Abstract: The results of activity buildup studies in the SM-1 (APPR-1) performed from February 1958 to January 1959 are reported. Data are presented on the extent, nature, and mechanism of the buildup of long-lived gamma emitting nuclides in the reactor primary system. Mathematical equations to describe the activity buildup are derived. Radiation levels after reactor shutdown are presented, as well as the predicted radiation levels at the end of core life.

Abstract: Critical experiment studies were performed, varying the parameters U235, B10 and metal to water ratio, in the SM-2 7 x 7 core configuration with 38 stationary elements and seven control rods of the SM-1 (APPR-1) type. An experimental mock-up of the SM-1 was assembled using the basic SM-2 fuel plates. Excellent agreement between the SM-1 boron loading, determined by chemical analysis, and the SM-1 mock-up boron loading, for equivalent bank positions, was noted. Several SM-2 mock-ups, cold clean and midlife, were assembled and studied with regard to reflector effects, flow divider effects, relative control rod array worths, critical rod configurations, and relative power distributions. The results of these experiments indicate as satisfactory a U235 loading of 36.4 Kg and a B10 loading of 63.4 grams for the SM-2. Attention is drawn to numerous power peaks present in the active core. The open seven control rod array has a slight reactivity advantage over the closed seven array and consequent minor disadvantage with respect to "stuck rod" criteria.