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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Development Efforts for Detritiating Legacy Heavy Water Moderator

Conclusions • Department of Energy is evaluating reclaiming contaminated heavy water to commercial virgin heavy water specifications • SRNL evaluated leading commercial technologies to detritiate heavy water • To minimize the process hazards, water distillation was proposed as the best candidate • Addition of LPCE and cryogenic distillation can help process 100% of water with little to no waste storage • Significant advances over the past 40 years, but demonstration system needed to prove necessary detritiation factors for heavy water

Angelette, Lucas M. [Savannah River National Labor↗
DOE OSTI2019

CNL Technologies for Heavy Water Detritiation - 19437

Canadian Nuclear Laboratories (CNL) is responsible for a large amount of heavy water owned by the Government of Canada. A significant portion of this heavy water has been downgraded and is chemically and/or radiologically contaminated (besides tritium). Storage, monitoring and disposal of this water incurs significant costs. Upgrading following chemical purification (including removal of radionuclides other than tritium) of this water is feasible with commercial processes. However, removal of the tritium to the level that would allow the heavy water to be available for non-nuclear applications requires very specialized processes. CNL has developed and demonstrated the Combined Electrolysis and Catalytic Exchange (CECE) detritiation technology to reduce the tritium to the level at which the heavy water can be classified as non-radioactive. The CECE process consists of a Liquid Phase Catalytic Exchange (LPCE) bed, where the transfer of hydrogen isotopes between water and gaseous hydrogen occurs, and an electrolysis cell (E-cell) that produces hydrogen and separates the isotopes of hydrogen, adding to the enrichment achieved in the LPCE catalyst bed. The application of the CECE technology to the tritium-contaminated heavy water would restore its full market value. As part of a project supported by CNL Decommissioning and Waste Management, a business case is being developed to build and operate a facility that will purify and detritiate heavy water to render it commercially attractive. The main goal of the current study is to evaluate the net benefits of detritiation and product sale versus the cost of permanent storage or disposal. Such a facility would not only eliminate the need to store the heavy water as a radioactive waste material and provide revenue, but would also serve as a demonstration of CNL's technology for similar applications elsewhere. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2024

Detritiation and Recovery of Heavy Water Moderator for Commercial Use

Historical Inventory Savannah River Site hosted five tritium production reactors from the 1950s through 1990s • Pressurized heavy water reactor • D2O moderator • Approximately 1900 m3 of legacy moderator water is in storage • Ranges from 1% D2O to 99.8% D2O • Varying amounts of tritium, relatively low amounts of other radioactive elements • Due to shortage in D2O production, US Department of Energy is investigating detritiating the heavy water for commercial uses

Angelette, Lucas M. [Savannah River National Labor↗
DOE OSTI2024

Physics analysis and design of heavy water reflected thermal test reactor

Here, this work investigates the option of modifying the Advanced Test Reactor by replacing the current beryllium reflector with heavy water. Such a change may provide some potential benefits for not only increasing the thermal irradiation capabilities but also resolving other problems such as reflector integrity issues due to fast fluence damage, which is always a limiting factor in the lifetime of the current beryllium reflector. This paper presents the analysis and estimation of the ATR core physics parameters by replacing the current beryllium reflector with heavy water (D 2 O). The paper first describes the details of two selected conceptual designs, which are partially reflected with either beryllium or graphite, and how they are derived from the baseline beryllium reflector concept. Then, reactor physics performance parameters for the two new concepts are assessed by comparing with those of the baseline concept. The performance parameters considered in this paper include in-pile tube neutron and gamma fluxes and heating rates, maximum loop voiding reactivity, core power behavior with different power splits, predicted cycle length with a given fuel loading, and thermal hydraulic analysis with a higher lobe power split. It is important to note that this study focuses on the reactor physics aspects and does not delve into the engineering challenges associated with such a design modification.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2023

Advanced Fuel Cycle Cost Basis Report: Module D1-7 Contact-Handled Pelletized Pressurized Heavy Water (PHWR) UOX Fuel Fabrication (Rev.1)

In addition to literature-based pressurized heavy-water reactor (PHWR) fuel price information in the 2017 AFC-CBR, the what-it-takes (WIT) unit cost data in this update is informed by new analysis and escalation of the 1978 PHWR-UOX fuel life cycle cost (LCC) data from ORNL reports prepared for the 1977–1980 Nonproliferation Alternative Systems Assessment Program (NASAP). (These reports are referenced and summarized in detail in Module D1-PR.) The PHWR fuel fabrication LCC data in these reports is scaled from a bottom-up cost estimate for a reference technology pressurized-water reactor (PWR)—uranium oxide (UOX) fuel fabrication plant by using algorithms that consider the manufacturing process complexity, fuel design complexity, plant floor space requirements, and the radiation and health, safety, and environmental (HS&E) regulatory environment of PHWR-UOX fuel production vis-à-vis light-water reactor (LWR)-UOX production (PWR fuel in this case). The module name has been changed from “Canadian Deuterium Uranium (CANDU)” to the more generic PHWR fuel fabrication in recognition that not all power reactors that might use this fuel type are considered. Unfortunately, the detailed algorithms and their design bases were not archived at the end of the NASAP effort of the commercial CANDU concept specifically developed in the middle of the last century by Atomic Energy of Canada Limited (AECL).

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2022

High-repetition-rate, multi-MeV deuteron acceleration from converging heavy water microjets at laser intensities of 10 21 W/cm 2

Herein we demonstrate high repetition-rate deuteron acceleration by irradiating a continuously flowing, ambient temperature liquid heavy water jet with the high-intensity ALEPH laser. The laser delivered up to 5.5 J (120 TW, 1.2 × 10 21 W/cm 2 ) laser energy on target at 0.5 Hz. A high repetition-rate Thomson parabola spectrometer measured the deuteron beam energy spectra on each shot for 60 sequential shots (two minutes). Peak fluxes of 5 x 10 10 deuterons/sr/pulse, corresponding to an average flux of 1.5 x 10 12 deuterons/sr/min, were demonstrated with deuteron energies reaching up to 4.4 MeV. High shot-to-shot stability is observed up to 40%–50% of the maximum deuteron energy. These deuteron beams are suited for fast neutron production through deuteron breakup in a converter yielding energies similar to deuteron–deuteron (D–D, 2.45 MeV) fusion reactions of importance for material damage studies.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
NASA NTRS1977

Study of the potential for improving the economics of hydrogen liquefaction through the use of centrifugal compressors and the addition of a heavy water plant

An approach to the liquefaction of hydrogen was developed which permits the application of standard centrifugal compressors in place of reciprocating machines. A second fluid, such as propane, is added to the hydrogen prior to compression to form a mixture having a molecular weight much greater than that of hydrogen alone, so that a standard centrifugal compressor can be used. After compression, the mixture is cooled to cryogenic temperature levels where the propane condenses out of the mixture and is separated as a liquid. Since a small amount of deuterium is produced during hydrogen liquefaction, the potential of recovering deuterium and selling it as a co-product was investigated. Deuterium, in the form of heavy water, can be used in certain nuclear reactors as a neutron moderator to reduce the neutron velocity and enhance the probability of neutron collision with uranium nucleii.

Baker, C. R.↗
DOE OSTI2019

Nuclear Archaeology to Distinguish Plutonium and Tritium Production Modes in Heavy-Water Reactors

Several nuclear archaeology techniques have been proposed to determine historic plutonium production in dedicated nuclear reactors. These methods rely on sampling materials from the reactor core or specially designed monitor tags, to examine suited isotopic ratios and deduce the amount of plutonium produced. However, some production reactors can be used to produce other isotopes than plutonium, such as tritium. If a reactor has been declared to produce tritium, it could be crucial to confirm that this was the case and that the reactor was not used to produce plutonium instead. In this paper, we describe how isotopic ratios discrepancies can be used to distinguish between plutonium and tritium production modes. Here, we present results obtained via the simulation of reactor lattices inspired by Savannah River Site heavy water production reactors and show that elements such as hafnium and tungsten can be conveniently used to detect undeclared production of plutonium.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2019

Neutron studies of gauge field and charge in Ih heavy-water ice

The distinctive character of water ice results from the partially disordered combination of covalent and hydrogen bonds in the network of hydrogen and oxygen atoms. The nontrivial hydrogen correlations we report in diffuse neutron scattering are analytically fit via a description of this state as a topological system exhibiting an emergent gauge field. This enables the density of correlation-terminating point defects to be decided as one defect per 500 oxygen sites at 30 K. Application of an analytical model of ice paves the way towards a detailed understanding of this ubiquitous solid.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
NASA NTRS1991

Stratospheric profiles of heavy water vapor isotopes and CH3D from analysis of the ATMOS Spacelab 3 infrared solar spectra

The isotopic composition of stratospheric water vapor and methane was investigated. Stratospheric profiles of HDO, (H-18)2O, (H-17)2O, and CH3D were derived from solar occultation spectra recorded on April 30 - May 1, 1985 by the Atmospheric Trace Molecule Spectroscopy Fourier transform spectrometer aboard Spacelab 3. The profiles of the three water-vapor isotopes showed an increase in the volume mixing ratio with altitude. The measured profiles of D/H in water vapor showed a large depletion in the lower stratosphere (about 63 percent relative to standard mean ocean water, SMOW, at 20 km) and a small increase in D/H with altitude at higher altitudes, up to 34 km. The D/H ratio in stratospheric methane was close to the corresponding isotopic ratio in SMOW.

Rinsland, C. P.↗
DOE OSTI2019

Amidoxime-Functionalized Macroporous Carbon Self-Refreshed Electrode Materials for Rapid and High-Capacity Removal of Heavy Metal from Water

Heavy metal pollution continues to be one of the most serious environmental problems which has attracted major global concern. Here, a rapid, high-capacity, yet economical strategy for deep cleaning of heavy metals ions in water is reported based on amidoxime-functionalized macroporous carbon electrode materials. The active sites of our material can be self-refreshed during the electrochemical removal process, which is different from traditional methods. The novel filter device in this work can purify contaminated water very rapidly (3000 L h –1 m –2 ), and can decrease heavy metal ion concentrations to below 5 ppb with a very short contact time (only 3 s). The original treatment efficiency of the device can be retained even after 1 week of continuous device operation. An extremely high removal capacity of over 2300 mg g –1 can be achieved with 2–3 orders of magnitude higher efficiency than that of surface adsorption-based commercial filters without any decay. Additionally, the cost of energy consumed in our method is lower than $6.67 × 10 –3 per ton of wastewater. We envision that this approach can be routinely applied for the rapid, efficient, and thorough removal of heavy metals from both point-of-use water and industrial wastewater.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Isotope effects on the high pressure viscosity of liquid water measured by differential dynamic microscopy

In this paper, differential dynamic microscopy is performed in diamond anvil cells to measure the viscosity of water along the 24 °C isotherm to high-pressure by determination of the tracer diffusion coefficient of monodisperse silica spheres of known diameter and application of the Stokes-Einstein-Sutherland equation. This technique allows liquid samples to be compressed to greater pressure prior to freezing than with other viscometry methods. The highest-pressure measurement was made at 1.67 GPa, considerably deeper into the supercompressed regime than previously reported. The effect of isotopic composition is investigated with samples of normal water, heavy water, and partially deuterated water. When data below 0.25 GPa are excluded a free volume model fits the observed viscosities well yielding a theoretical glass transition density close to that observed in very-high-density amorphous ice. The improved fit above 0.25 GPa coincides with the loss of other anomalous behaviors in liquid water caused by hydrogen bonding and represents a transition to properties closer to those of a simple liquid.

74 ATOMIC AND MOLECULAR PHYSICS↗
NASA NTRS1972

Reflectance of aqueous solutions

The optical properties and optical constants of water and aqueous solutions were studied to develop an accurate tabulation of graphical representations of the optical constants through a broad spectrum. Manuscripts of articles are presented concerning extinction coefficients, relative specular reflectance, and temperature effect on the water spectrum. Graphs of absolute reflectance, phase shifts, index of refraction, and extinction coefficients for water, heavy water and aqueous solutions are included.

Querry, M. R.↗
NASA NTRS1954

Effect of water on carbon monoxide-oxygen flame velocity

The flame velocities were measured of 20 percent oxygen and 80 percent carbon monoxide mixtures containing either light water or heavy water. The flame velocity increased from 34.5 centimeters per second with no added water to about 104 centimeters per second for a 1.8 percent addition of light water and to 84 centimeters per second for an equal addition of heavy water. The addition of heavy water caused greater increases in flame velocity with equilibrium hydrogen-atom concentration than would be predicted by the Tanford and Pease square-root relation. The ratio of the flame velocity of a mixture containing light water to that of a mixture containing heavy water was found to be 1.4. This value is the same as the ratio of the reaction rate of hydrogen to that of deuterium and oxygen. A ratio of reaction rates of 1.4 would also be required for the square-root law to give the observed ratio of flame-velocity changes.

Mcdonald, Glen E↗
NASA NTRS1979

Preparative cell electrophoresis at 1 and 0 gravity

It is attempted to show that the use of heavy water (D2O) as starting cushion for the cells combines the advantages of the required density difference, with no lasting biochemical or physiochemical influence on the cells. Phosphate buffers of low ionic strength were prepared in distilled water or heavy water. A vertical starch gel electrophoresis was used to support a cylindrical polystyrene electrophoresis tube used for lymphocyte separations, 25 cm in length and 0.75 cm I.D., prepared from a 10 ml disposable pipet. Erythrocyte separations were carried out in a jacketed rectangular plexiglas chamber. It is pointed out that the described preparative D2O gradient electrophoresis method cannot be readily used for the measurement of electrophoretic mobilities for analytical purposes. However, for the preparative separation of cells with only slightly different electrokinetic properties the method appears promising, simple, and entirely inocuous to the cells.

Van Oss, C. J.↗