ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
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Division Spotlight
Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
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!
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Latest News
El Salvador: Looking to nuclear
In 2022, El Salvador’s leadership decided to expand its modest, mostly hydro- and geothermal-based electricity system, which is supported by expensive imported natural gas and diesel generation. They chose to use advanced nuclear reactors, preferably fueled by thorium-based fuels, to power their civilian efforts. The choice of thorium was made to inform the world that the reactor program was for civilian purposes only, and so they chose a fuel that was plentiful, easy to source and work with, and not a proliferation risk.
N. J. Peters, K. Kutikkad
Nuclear Technology | Volume 201 | Number 1 | January 2018 | Pages 80-98
Technical Paper | doi.org/10.1080/00295450.2017.1398582
Articles are hosted by Taylor and Francis Online.
The details of robust computational and novel semiempirical methodologies that were developed and tested at the University of Missouri Research Reactor (MURR) to accurately determine the possibility of a “hot” startup and the estimated critical position (ECP) of the control rods following an unplanned shutdown are presented. The computations, based on a modified coupled MCNP5-ORIGEN2 code system and using ENDF/B-VII.0 and TENDL-2013 nuclear data sets, accurately simulate the MURR core operational histories while predicting the critical rod positions within ±0.001 Δk/k of experimental critical data. In this study, using the coupled MCNP5-ORIGEN2 computations, various core-specific parameters were methodically characterized and were adapted into a semiempirical formulation better suited for practical reactor operations. The predictive capabilities of these novel semiempirical approaches regarding core criticality and ECPs required utilizing, for the first time, the net transient response of the negative reactivity worth for necessary fission product poisons including 135mXe and several others. Calculation-to-experiment deviations in hot-startup criticals and the corresponding control rod positions are shown to be less than ±0.03% Δk/k and ±1% difference in relative rod position, respectively.