"BWR Burnup Methods." Nuclear Applications, 6(1), pp. 95–96 Additional informationNotes on contributorsGeorge A SoferGeorge A. Safer, (ScD, MIT) is manager of the Nuclear Design Department, United Nuclear Corporation, Res ear chand Enginerring Center, Elmsford, N.Y. After leading a series of conceptual design studies, which included steam-cooled and sodium-cooled fast breeders and 96 fog-cooled light- and heavy-water moderated reactors for Nuclear Development Associates, he recently concentrated on compilation and development of BWR and PWR core physics methods. These methods are now used in the fuel management of the Dresden Unit 1 reactor and in nuclear design and fuel management of the Donald C. Cook 1050 MW(e) PWR and Con Edison's Unit 4 1100 MW(e) BWR.
"Too Many Compromises." Nuclear Applications, 6(6), pp. 598–599 Additional informationNotes on contributorsLeonard S. KisslingerProfessor Leonard S. Kisslinger has been at Case Western Reserve University since receiving his PhD (University of Indiana) in 1956, except for periods spent at the Bohr Institute in Copenhagen, at the Weizmann Institute, and at MIT. He has been a visiting physicist at Brookhaven, Oak Ridge, and Lawrence Radiation Laboratories, and a consultant to Los Alamos Scientific Laboratory. His fields of research include nuclear models and structure, particle physics, and the manybody problem.
"Source Book for Plastics Testing." Nuclear Applications, 6(6), p. 599 Additional informationNotes on contributorsAlbert LightbodyAlbert Lightbody, Chief of the Chemistry Research Department of the US Naval Ordnance Laboratory (NOL), White Oak, Silver Spring, Md., has been interested in plastics research and engineering since 1943. A past director of the Society of Plastics Engineers and now the Secretary of the Plastics Institute of America, he was instrumental in developing a specimen, known throughout the industry as the NOL ring, for testing of filament-wound composites. His PhD (physical chemistry) was earned from the University of Nebraska in 1933.
Production rates (atoms/gram megawatt day) of 58Co, 54Mn, 55Fe, 63Ni, and 60Co in the Experimental Breeder Reactor-II (EBR-II) irradiated stainless steel are reported. These rates can be used as precise flux and fluence monitors in fast reactors when appropriate spectrum-averaged cross sections are applied. Seven spectrum-averaged cross sections for the core and four spectrum-averaged cross sections at eight radial positions in EBR-II are also reported. The ratio of 54Mn/55Fe atoms produced from 54Fe represents a sensitive spectral hardness indicator for fast-reactor spectra. This study also indicates that in EBR-II the flux per megawatt measured at high power is the same as that measured at low power by other authors. Results show that a diffusion theory calculation provides a reasonably accurate representation of the flux in the core of EBR-II but overestimates the flux in the blanket region.
This study of EBR-II operating behavior, which began with a reexamination of the thermal analysis of fuel pins under varying rates of coolant flow, incorporates the recent interpretations of the bowing behavior of the subassemblies. The nonlinear bowing effects are combined with the linear expansion effects in equations that express the power-reactivity decrement as a function of both power and flow. Comparison with experiments indicates agreement to within a few inhours. Differentiation of the equations leads to expressions for power and flow coefficients of reactivity. The reduced flow data are used to determine an effective average thermal expansion coefficient for the fuel.
Certain elements of biological interest cannot be measured by conventional neutron activation analysis. Some elements lead, by (n,γ) reaction, to radionuclides too short-lived to be measured by their gamma activity or to stable elements. With other elements, such as sulfur and phosphorus, neutron activation produces pure beta emitters, which are difficult to measure without destruction of the sample.Samples of blood, bone, and hair were irradiated in vitro at the outlet of the curved neutron guide of the Saclay reactor EL3 in a flux of thermal neutrons (< 0.127 eV). The capture spectra were recorded by means of a 20 cm3 Ge(Li) detector. The elements H, B, Cl, Na, K, N, S, and P were identified.In addition, boron, hydrogen, and chlorine were determined in two samples of cabbage and brown seaweed. Since a homogeneous irradiation was impossible because of the weak penetration of the thermal neutrons in the biological sample, it was necessary to use an internal standard (mercury). By the capture-gamma method of analysis it was also possible to measure in vivo the Ca/Cl mass ratio of a human tibia.
The radiolysis of CF4, alone and mixed with UF6, UF6 + N2, UF6 + Ar, UF6 + Xe, UF6 + SF6, and UF4 + C by gamma photons from 60Co or by fission fragments from 235U gave C2F4 as the principal product. Traces of C2F6O and C3F3O were also found. In the gamma irradiation of CF4 + UF4 + C, charcoal acted as a fluorine scavenger and increased the consumption of CF4, but N2, Ar, Xe, and SF6 showed no measurable scavenging effects. During the fission fragment irradiations, C, N2, and Xe acted as scavengers, but such action by Ar or SF6 was not detected. The results for 60Co gamma irradiations and for fission fragment irradiations could be explained by a dynamic interconversion between CF4 and the products C2F4 and F2. A mathematical model that related the extent of interconversion with energy deposition was formulated.
Liquid potassium was circulated between 1200 and 1600°F in 31 Type-316 stainless-steel thermal convection loops and one forced circulation loop. Each loop contained a string of niobium-1% zirconium (Nb-1% Zr) alloy and stainless-steel test specimens positioned along the entire heated leg. To follow corrosion as a function of time and temperature, the test specimens were examined at 500 to 2500 h intervals. Controlled additions of interstitial impurities to the potassium were made in some thermal convection loops at the start of the test. Oxygen additions to the potassium sharply accelerated the initial rate of Nb-1% Zr surface removal but produced no identifiable oxide film or microstructural changes. The initially high weight-loss rates, observed in oxygen addition loops, decayed rapidly with time, returning essentially to normal rates (in the absence of further oxygen additions) after 2500 h. Oxygen additions produced very little effect on the stainless-steel corrosion rates, presumably due to rapid gettering of the added oxygen by the Nb-1% Zr.Similar tests in a forced circulation loop, with potassium velocities past the test specimens 18 times higher than in the thermal convection loops, showed that any effects of velocity on the Nb-1% Zr corrosion rate were far overshadowed by effects that are assumed to be related to oxygen in the potassium.
The stack effluent of a nuclear fuel reprocessing plant would be expected to contain sufficient tritium to serve as a radioactive tracer for the plume. In order to make use of this built-in tracer, a silica gel sampler for tritiated moisture was developed, which permits large scale sampling.An intensive study of the area surraunding Nuclear Fuel Services, Inc. was undertaken during the summer of 1967 to determine experimentally the maximum concentration (Cmax) of the stack effluent using tritiated moisture as the tracer. Sampling legs that radiated from the stack were established. During a two-month period >700 samples were collected on 7 sampling legs.The average tritium radioactivity on the sampling leg northwest of the plant (leg G) exceeded 1000 tritium units (TU) 71% of the time for the 28 sampling periods studied. In 11 of 28 cases a maximum concentration of >3000 TU occurred. It was definitely demonstrated that a Cmax can be determined by tracing with tritiated moisture.Based on experimental Cmax values, an estimate of the emission rate, Q, was made under various meteorological conditions. The possibility of a secondary saurce of tritiated moisture influencing measurement of stack-emitted tritium was considered.
"Nuclear Applications." Nuclear Applications, 6(1), p. 5 Additional informationNotes on contributorsD. A. CostanzoR. A. MacGregor, surveyor, geologist, and presently underground superintendent, has been with Stanrock Uranium Mines (Ontario) since 1960. He developed bacterial leaching of uranium at Stanrock, the first mine in the area to use this process on a commercial scale.L. T. CorbinT. Roger Billeter (left) (MSEE, University of Washington, 1961), a senior research engineer at BatteZZe-Northwest's Instrument Research and Development Section, has primary responsibility for development of temperature and impurity measuring sensors. Donald P. Brown (center) (MSEE, University of Washington, 1965) is a senior research engineer specializing in thermal- and fast-neutron detectors for in-core application. Ward G. Spear (MSEE, University of Idaho, 1960) manages the IRD Section.
