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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.
Conference on Nuclear Training and Education: A Biennial International Forum (CONTE 2023)
February 6–9, 2023
Amelia Island, FL|Omni Amelia Island Resort
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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Nuclear Science and Engineering
Fusion Science and Technology
Nuclear energy: enabling production of food, fiber, hydrocarbon biofuels, and negative carbon emissions
In the 1960s, Alvin Weinberg at Oak Ridge National Laboratory initiated a series of studies on nuclear agro-industrial complexes1 to address the needs of the world’s growing population. Agriculture was a central component of these studies, as it must be. Much of the emphasis was on desalination of seawater to provide fresh water for irrigation of crops. Remarkable advances have lowered the cost of desalination to make that option viable in countries like Israel. Later studies2 asked the question, are there sufficient minerals (potassium, phosphorous, copper, nickel, etc.) to enable a prosperous global society assuming sufficient nuclear energy? The answer was a qualified “yes,” with the caveat that mineral resources will limit some technological options. These studies were defined by the characteristic of looking across agricultural and industrial sectors to address multiple challenges using nuclear energy.
Peter Yarsky, Andrew Bielen
Nuclear Technology | Volume 207 | Number 4 | April 2021 | Pages 627-635
Technical Note | doi.org/10.1080/00295450.2020.1774260
Articles are hosted by Taylor and Francis Online.
The U.S. Nuclear Regulatory Commission (NRC) staff often perform confirmatory analyses using the TRAC/RELAP Advanced Computational Engine (TRACE) and Purdue Advanced Reactor Core Simulator (PARCS) codes to assist in regulatory decision making. Recently, the NRC staff have performed numerous such analyses of anticipated transient without SCRAM (ATWS) with core instability (ATWS-I) scenarios for boiling water reactor license amendment requests to expand the power/flow operating domain. In the conduct of these confirmatory analyses, the staff have simulated oscillatory conditions in the reactor core under certain ATWS conditions that result in regional mode (or out-of-phase mode) power oscillations. The nature of these regional oscillations may present a challenge to fuel damage limits. Therefore, there has been interest in methods to identify the most limiting point in cycle exposure. It has been conventional wisdom that the core is most susceptible to regional mode oscillations when the fission cross section is greatest, leading to the common practice of analyzing these events at the peak hot excess (PHE) exposure point in the cycle. The staff have found some limitations in applying the PHE concept in a consistent manner. In the current work, the NRC staff have developed a more rigorous method for identifying the most limiting cycle exposure by directly considering the core flow rate, the axial power distribution, the first harmonic mode shape, and the eigenvalue separation between the fundamental and first harmonic modes. This method is a more rigorous method to screen the various exposures between beginning and end of cycle. An example case is shown to demonstrate the application of this methodology.