ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Mathematics & Computation
Division members promote the advancement of mathematical and computational methods for solving problems arising in all disciplines encompassed by the Society. They place particular emphasis on numerical techniques for efficient computer applications to aid in the dissemination, integration, and proper use of computer codes, including preparation of computational benchmark and development of standards for computing practices, and to encourage the development on new computer codes and broaden their use.
Meeting Spotlight
2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Latest Magazine Issues
Apr 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
June 2024
Nuclear Technology
May 2024
Fusion Science and Technology
Latest News
Commercial nuclear innovation "new space" age
In early 2006, a start-up company launched a small rocket from a tiny island in the Pacific. It exploded, showering the island with debris. A year later, a second launch attempt sent a rocket to space but failed to make orbit, burning up in the atmosphere. Another year brought a third attempt—and a third failure. The following month, in September 2008, the company used the last of its funds to launch a fourth rocket. It reached orbit, making history as the first privately funded liquid-fueled rocket to do so.
R. Gwin, D. W. Magnuson
Nuclear Science and Engineering | Volume 12 | Number 3 | March 1962 | Pages 364-380
Technical Paper | doi.org/10.13182/NSE62-A28087
Articles are hosted by Taylor and Francis Online.
The thermal value of eta for U233 and U235 has been determined in a series of experiments on unreflected homogeneous aqueous solutions of the two isotopes. These experiments also yield a value for the neutron age and the limiting concentrations of the fissile isotope in the aqueous solutions for infinite volumes. Auxiliary experiments, establishing limits of error, testing certain aspects of the theoretical model employed, and experimentally determining the parameters in the critical equation, have been performed. Experiments performed with 27-in.- and 48-in.-diam spheres, and 5-ft- and 9-ft-diam cylinders have yielded consistent values of eta. Measurements of the nonleakage probability in cylindrical geometry have given values consistent with those predicted by a two-group model in which the theoretical value of the age was used. Within the experimental error no differences were found in the ages of fission neutrons for U233 and U235. The average thermal values of eta determined are: for U233, 2.292 ± 0.015 and for U235, 2.076 ± 0.015. The 2200 meters/sec values are the same since the g-factors for eta are unity. The value of the neutron age to the indium resonance energy for U235 fission neutrons in water was found to be 25.6 ± 1.3 cm2. The minimum U233 and U235 critical densities for these nitrate solutions were found to be 11.25 ± 0.10 gm/liter and 12.30 ± 0.10 gm/liter for U233 and U235, respectively.
