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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.
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International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver Downtown
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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Dragonfly, a Pu-fueled drone heading to Titan, gets key NASA approval
Curiosity landed on Mars sporting a radioisotope thermoelectric generator (RTG) in 2012, and a second NASA rover, Perseverance, landed in 2021. Both are still rolling across the red planet in the name of science. Another exploratory craft with a similar plutonium-238–fueled RTG but a very different mission—to fly between multiple test sites on Titan, Saturn’s largest moon—recently got one step closer to deployment.
On April 25, NASA and the Johns Hopkins University Applied Physics Laboratory (APL) announced that the Dragonfly mission to Saturn’s icy moon passed its critical design review. “Passing this mission milestone means that Dragonfly’s mission design, fabrication, integration, and test plans are all approved, and the mission can now turn its attention to the construction of the spacecraft itself,” according to NASA.
Bojan Petrovic
Nuclear Technology | Volume 168 | Number 2 | November 2009 | Pages 438-443
Shielding | Special Issue on the 11th International Conference on Radiation Shielding and the 15th Topical Meeting of the Radiation Protection and Shielding Division (Part 2) / Radiation Protection | doi.org/10.13182/NT09-A9222
Articles are hosted by Taylor and Francis Online.
The integral configuration of the International Reactor Innovative and Secure (IRIS) with its relatively thick downcomer region within the reactor vessel and compact spherical steel containment offers potential for a significant dose reduction but also presents challenges for the related deep-penetration shielding analyses due to the large spatial domain. It is necessary to determine the radiation field throughout the 25-m-diam spherical containment and into the adjoining auxiliary building.The shielding analysis is being performed using the "traditional" deterministic SN and Monte Carlo approaches and codes (TORT and MCNP, respectively). In the preliminary, scoping phase, the radiation field is sought "everywhere" throughout the power plant to identify any possible shielding issues. This is very challenging for typical Monte Carlo variance-reduction methods, which are devised and may work very well to provide results in a limited region or for individual "detectors" rather than everywhere. However, the recently developed FW-CADIS method, implemented within the MAVRIC sequence of the SCALE code system, aims to address this problem. It uses forward and adjoint deterministic SN calculations to generate effective biasing parameters for Monte Carlo simulations throughout the problem. Previous studies have confirmed its potential for obtaining Monte Carlo solutions with acceptable statistics over large spatial domains.The objective of this work was to evaluate the applicability of FW-CADIS/MAVRIC to efficiently perform the required shielding analysis of IRIS. For that purpose, a representative model was prepared, retaining the main problem characteristics, i.e., a large spatial domain (>10 m in each dimension) and significant attenuation (more than 12 orders of magnitude), but geometrically rather simplified at this stage of evaluation. The obtained preliminary results indicate that the FW-CADIS method implemented through the MAVRIC sequence in SCALE will enable determination of the radiation field throughout the large spatial domain of the IRIS nuclear power plant.
