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
Nuclear Installations Safety
Devoted specifically to the safety of nuclear installations and the health and safety of the public, this division seeks a better understanding of the role of safety in the design, construction and operation of nuclear installation facilities. The division also promotes engineering and scientific technology advancement associated with the safety of such facilities.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
April 2025
Fusion Science and Technology
Latest News
First astatine-labeled compound shipped in the U.S.
The Department of Energy’s National Isotope Development Center (NIDC) on March 31 announced the successful long-distance shipment in the United States of a biologically active compound labeled with the medical radioisotope astatine-211 (At-211). Because previous shipments have included only the “bare” isotope, the NIDC has described the development as “unleashing medical innovation.”
Yoshiro Asahi, Tomoaki Suzudo, Nobuyuki Ishikawa, Toru Nakatsuka
Nuclear Science and Engineering | Volume 152 | Number 2 | February 2006 | Pages 219-235
Technical Paper | doi.org/10.13182/NSE06-A2577
Articles are hosted by Taylor and Francis Online.
An analysis of a boiling water reactor turbine trip was performed with the THYDE-NEU code. In spatial kinetics, reactivity was not used since the three-dimensional transient diffusion equation was solved with the implicit direct integration method. The plant was treated as a closed coolant system, and hence, it was necessary to cope with thermal-hydraulic behaviors at pressures as low as the atmospheric pressure. At low pressures, nonlinearity of the thermal-hydraulic equation is enhanced, and hence, a thermal nonequilibrium model is required. To satisfy the measured initial pressure distribution within the reactor, it was necessary to have the moisture separator model and to account for a reversible pressure drop at a junction with a flow area change. Among the parameters in THYDE-NEU is in the thermal nonequilibrium model in addition to C1 and C2 regarding the manner in which to express the coolant density used in the table look-up of cross sections. For a pair of C1 and C2, it is possible to find parametrically a value of , namely, C, so that THYDE-NEU can reproduce the experimental fact that the core-averaged local power range monitor output RAPRM reached 0.95 at 0.63 s to generate a scram signal. One of the calculations with C was compared with the experiment. It was shown that the spatial kinetics results are sensitive to the temporal behavior of the bypass valve opening. Among the assumptions in use, those to be scrutinized before further performing sensitivity calculations were indicated.
