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
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
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
May 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
June 2024
Nuclear Technology
Fusion Science and Technology
Latest News
Proving DRACO will deliver
The United States is now closer than it has been in over five decades to launching the first nuclear thermal rocket into space, thanks to DRACO—the Demonstration Rocket for Agile Cislunar Orbit.
M. Gentili, B. Fontaine, G. Rimpault
Nuclear Technology | Volume 192 | Number 1 | October 2015 | Pages 11-24
Technical Paper | Fission Reactors | doi.org/10.13182/NT14-123
Articles are hosted by Taylor and Francis Online.
Fast reactor designs are currently being revisited aiming at having a consolidated safety dossier. In that frame, studying any perturbation of nominal operating condition is mandatory.
Among different initiators, particular attention is being paid to reactivity insertion due to core assembly bowing and deformation and induced lattice readjustments as a consequence of events such as earthquakes.
In this study, a deterministic calculation scheme based on the mesh projection method has been used in order to evaluate the reactivity changes occurring in a deformed sodium fast reactor core.
With the microscopic cross sections calculated by ECCO, full three-dimensional core calculations are being conducted with ERANOS (DIF3D), VARIANT, and SNATCH to solve neutron transport equations in either diffusion, nodal variational, or Sn transport approximations.
A simple analytical model based on perturbation theory has been developed to identify the main phenomena leading to changes in the core reactivity. Reactivity changes induced by small deformations can be estimated as a summation of reactivity perturbations of individual subassemblies.
The results obtained with this method have been checked by comparing them to those obtained with Monte Carlo simulations. A good agreement is being found allowing the use of this method in realistic problems with significant computer resource reduction.
The different contributions to the reactivity changes confirm the results of the analytical model.