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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Fundamental Radiation Chemistry

An overview presentation for the Fundamental Radiation Chemistry component of the Material Recovery and Waste Form Development campaign to be delivered to the campaign team. The overview includes all major findings from FY19 research projects, current state of FY20 research projects, additional projects completed between FY19 and now, and finally our vision for the future direction of the Fundamental Radiation Chemistry component.

38 - RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCL↗
DOE OSTI2022

Recent Advances in Actinide Radiation Chemistry

The attached presentation discusses recent advances in actinide radiation chemistry from the perspective of the INL Center for Radiation Chemistry Research, to be presented virtually at the Los Alamos National Laboratory G. T. Seaborg Institute Seminar Series.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2025

Radiation Chemistry and the Nuclear Fuel Cycle

This presentation will give a general overview of radiation chemistry in the nuclear fuel cycle, and outline some relevant work being conducted in the INL Radiochemical Separations and Radiation Science Department. This will include a discussion of using multiscale modeling to study plutonium radiation chemistry in nitric acid solutions. (Presentation cancelled)

38 - RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCL↗
NASA NTRS1992

Radiation chemistry in the Jovian stratosphere - Laboratory simulations

The results of the present low-pressure/continuous-flow laboratory simulations of H2/He/CH4/NH3 atmospheres' plasma-induced chemistry indicate radiation yields of both hydrocarbon and N2-containing organic compounds which increase with decreasing pressure. On the basis of these findings, upper limits of 1 million-1 billion molecules/sq cm/sec are established for production rates of major auroral-chemistry species in the Jovian stratosphere. It is noted that auroral processes may account for 10-100 percent of the total abundances of most of the observed polar-region organic species.

Mcdonald, Gene D.↗
DOE OSTI2024

Sulfur Chloride Radiation Chemistry Activities

Presentation highlight the INL Center for Radiation Chemistry Research's contributions the Material Recovery & Waste Form Development Campaign on sulfur chloride processing technologies.

38 - RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCL↗
DOE OSTI2025

The inorganic chemist's guide to actinide radiation chemistry: a review

This review aims to provide an overview of the current state of radiation chemistry with respect to the actinide elements, thorium through californium. Despite the inherent radioactivity of the actinides, only a few studies explore the effects of ionizing radiation on their redox chemistry and surrounding environment. This fundamental knowledge gap, coupled with the current renaissance in actinide-based technologies such as nuclear power, space exploration, and medicine, underscores the importance of research in this interdisciplinary area. This review will focus on the interactions between reactive species formed by radiolysis with actinides and their complexes, offering an inorganic chemist's perspective on research in radiation chemistry. In addition, a thorough discussion of our current understanding of radiation-induced changes in actinide speciation in both aqueous solution and the solid-state will be provided, focusing on changes in oxidation state distribution, complexation, and secondary coordination effects within inorganic materials. Finally, this review will discuss challenges and opportunities for inorganic chemists to explore this unique intersection of fields.

Actinides↗
NASA NTRS2014

A Radiation Chemistry Code Based on the Greens Functions of the Diffusion Equation

Ionizing radiation produces several radiolytic species such as.OH, e-aq, and H. when interacting with biological matter. Following their creation, radiolytic species diffuse and chemically react with biological molecules such as DNA. Despite years of research, many questions on the DNA damage by ionizing radiation remains, notably on the indirect effect, i.e. the damage resulting from the reactions of the radiolytic species with DNA. To simulate DNA damage by ionizing radiation, we are developing a step-by-step radiation chemistry code that is based on the Green's functions of the diffusion equation (GFDE), which is able to follow the trajectories of all particles and their reactions with time. In the recent years, simulations based on the GFDE have been used extensively in biochemistry, notably to simulate biochemical networks in time and space and are often used as the "gold standard" to validate diffusion-reaction theories. The exact GFDE for partially diffusion-controlled reactions is difficult to use because of its complex form. Therefore, the radial Green's function, which is much simpler, is often used. Hence, much effort has been devoted to the sampling of the radial Green's functions, for which we have developed a sampling algorithm This algorithm only yields the inter-particle distance vector length after a time step; the sampling of the deviation angle of the inter-particle vector is not taken into consideration. In this work, we show that the radial distribution is predicted by the exact radial Green's function. We also use a technique developed by Clifford et al. to generate the inter-particle vector deviation angles, knowing the inter-particle vector length before and after a time step. The results are compared with those predicted by the exact GFDE and by the analytical angular functions for free diffusion. This first step in the creation of the radiation chemistry code should help the understanding of the contribution of the indirect effect in the formation of DNA damage and double-strand breaks.

Plante, Ianik↗
NASA NTRS2011

Step-by-Step Simulation of Radiation Chemistry Using Green Functions for Diffusion-Influenced Reactions

Radiolytic species are formed approximately 1 ps after the passage of ionizing radiation through matter. After their formation, they diffuse and chemically react with other radiolytic species and neighboring biological molecules, leading to various oxidative damage. Therefore, the simulation of radiation chemistry is of considerable importance to understand how radiolytic species damage biological molecules [1]. The step-by-step simulation of chemical reactions is difficult, because the radiolytic species are distributed non-homogeneously in the medium. Consequently, computational approaches based on Green functions for diffusion-influenced reactions should be used [2]. Recently, Green functions for more complex type of reactions have been published [3-4]. We have developed exact random variate generators of these Green functions [5], which will allow us to use them in radiation chemistry codes. Moreover, simulating chemistry using the Green functions is which is computationally very demanding, because the probabilities of reactions between each pair of particles should be evaluated at each timestep [2]. This kind of problem is well adapted for General Purpose Graphic Processing Units (GPGPU), which can handle a large number of similar calculations simultaneously. These new developments will allow us to include more complex reactions in chemistry codes, and to improve the calculation time. This code should be of importance to link radiation track structure simulations and DNA damage models.

Plante, Ianik↗
NASA NTRS2011

Step-by-Step Simulation of Radiation of Radiation Chemistry Using Green Functions for Diffusion-Influenced Reactions

The irradiation of biological systems leads to the formation of radiolytic species such as H(raised dot), (raised dot)OH, H2, H2O2, e(sup -)(sub aq), etc.[1]. These species react with neighboring molecules, which result in damage in biological molecules such as DNA. Radiation chemistry is there for every important to understand the radiobiological consequences of radiation[2]. In this work, we discuss an approach based on the exact Green Functions for diffusion-influenced reactions which may be used to simulate radiation chemistry and eventually extended to study more complex systems, including DNA.

Plante, Ianik↗
DOE OSTI2024

Backend Nuclear Fuel Cycle Radiation Chemistry

Given global commitments to significantly increase nuclear energy capacity, it is now more important than ever to develop efficient used nuclear fuel management strategies to improve resource utilization, energy security, and waste minimization. Here, an overview of nuclear energy, backend fuel cycle challenges, and advances in used nuclear fuel reprocessing radiation chemistry will be presented. More specifically, the use of electron pulse irradiation techniques to explore radiation-induced reaction mechanisms in actinide containing solutions and solvent systems.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2020

Radiation Chemistry Research for Improved Nuclear Fuel Cycles

Nuclear energy is a key component of a global, low-carbon energy future. One of the challenges facing large-scale deployment of nuclear power is the long-term disposition of used nuclear fuel. Due to the political and technical challenges of siting deep geologic storage facilities, reprocessing of used nuclear fuel is desirable to reduce the total volume and decay heat of waste requiring long-term storage, enabling efficient usage of geologic storage repositories. However nuclear fuel reprocessing is complicated by intense multi-component radiation fields that degrade solvent systems that are used for this purpose. Resulting radiolytic degradation can result in reduced performance over time, and generation of additional waste. Thus, an understanding of the radiation-induced chemistry of these reprocessing solvent systems is crucial to for the development of new, radiation-resistant processes for efficiently treating used nuclear fuel. Controlled irradiation experiments combined with high-performance chromatography and mass spectrometry have provided comprehensive knowledge of radiolytic degradation pathways and kinetics, which is needed to predict the effect of radiation-induced chemistry on the performance of the nuclear fuel reprocessing technology. This talk will give an overview of recent progress in research on the radiation chemistry of fuel reprocessing molecules conducted by the Idaho National Laboratory Center for Radiation Chemistry Research (CR2) in conjunction with the Molecular Mass Spectrometry and Chromatography group.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗