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 Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
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
May 2024
Nuclear Technology
Fusion Science and Technology
Latest News
Former Exelon CEO Chris Crane remembered for “transformational milestones”
Crane
Exelon announced that Chris Crane, the company’s former chief executive, passed away on Saturday in Chicago at the age of 65.
Crane served as the company’s president and CEO from 2012 until his retirement in December 2022. During his tenure, he steered the energy company through several transformational milestones, including the successful mergers with Constellation Energy in 2012 and Pepco Holdings in 2016, creating the largest utility business by customer count in the United States.
In 2022, with the spin-off of Constellation as the generation and retail side of energy business (with the largest U.S. nuclear fleet), Crane led the creation of a stand-alone transmission and delivery energy company.
Delgersaikhan Tuya, Toru Obara
Nuclear Science and Engineering | Volume 193 | Number 5 | May 2019 | Pages 481-494
Technical Paper | doi.org/10.1080/00295639.2018.1540209
Articles are hosted by Taylor and Francis Online.
A multiregion integral kinetic (MIK) code based on the integral kinetic model and a Monte Carlo neutron transport method has been developed with a new time-dependent feedback modeling capability. The current MIK code is applicable to the supercritical power transient following reactivity insertion in a fissile system of arbitrary geometry and composition, taking its feedback mechanisms into account. The new time-dependent feedback modeling capability allows a more direct and accurate treatment of complicated and nonlinear feedback mechanisms in a given system. The purpose of this study is to verify the MIK code and its time-dependent feedback modeling capability through various supercritical transient experiments conducted at the Godiva, TRACY, and SILENE facilities. Specifically, four supercritical experiments were selected and simulated using the MIK code. The various complicated feedback mechanisms—thermal expansion in Godiva, and Doppler broadening, thermal expansion, and radiolytic gas creation in TRACY and SILENE—provide a good benchmark for verifying the MIK code and its time-dependent feedback model. The obtained results show generally good, albeit occasionally poor, agreement with experimental results depending on the specific experiment. When the reasons for the poor agreement are considered, however, it may be concluded that the simulated results show promising agreement with the experiments, verifying the MIK code and its time-dependent feedback modeling capability.