Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “water detritiation”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

9 records
All sourcesNASA NTRSDOE OSTI
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

Approach to Startup Inventory for Viable Commercial Power Plant

Summary • FPP realization within the next 10-15 years will require dedicated efforts to improve DIR, burn fraction, fueling efficiency, and/or processing times. • Modest improvements from either the fuel cycle side or plasma physics side should be possible with considered allocation of R&D funding. • Current gaps in particular include blanket extraction at scale, improved efficiency in isotope separation and detritiation, and maximizing DIR efficiency. • Total costs for FPP construction and commissioning depend heavily on site regulation, so decreases in required SI and OI can lead to large decreases in capital outlay. • Some subsystems in the fuel cycle are required from a environmental management perspective but are both energetically expensive and time consuming, particularly water detritiation. • Low inventories but high capital and operational costs mean a centralized water detritiation plant could greatly improve likelihood of deployment of multiple FPPs on the same time scale.

MALONE, COLLIN↗
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 OSTI2020

Chromatographic Modeling of 1-Foot Detritiation Test Column Results for the Optimization of Regeneration Time

This report documents the methods and results of a modeling study on a series of data generated by 1-foot test columns for the Water Detritiation project. In order to compliment modeling work already in progress on this project, a purely empirical curve-fitting approach is used in this study to determine chromatographic performance indicators such as retention time, curve width, and the number of chromatographic stages. The data used in this study comes from four sets of chromatographic test separations performed in March through May of 2017 using 1-foot columns. All are using the same flow rates and temperature (room temperature, nominally 25 C°). The first set of data (referred to in this report as the Column 1 data) is a series of twelve breakthrough curve measurements. Prior to each of these twelve runs, the column was regenerated by flowing hydrogen gas through the column, for increasing amounts of time, ranging from 2 hours to 25 hours. The second set of data (referred to as the Column 2 data) is comprised of five measurements of breakthrough curves measured in similar fashion as the Column 1 data, across a range of regeneration times from 2 to 21 hours. The third set of data (referred to as the Purge data) is of three breakthrough curves, measured after a regeneration time of 8 hours, which takes place after a nitrogen purge of 15, 30, or 45 minutes. The fourth data set is a series of five breakthrough curve measurements using a 2 nd batch of stationary phase, taken after regeneration times ranging from 2 to 20 hours. The overall modeling approach is as follows. First, the data is pre-processed for formatting, artifact removal, and is normalized. The data is then fit by integrated versions of four common chromatographic models. The best model is chosen based on the predictive performance of the model, and chromatographic performance values are calculated based on the best model’s fit parameters. Each of these processes are detailed below.

42 ENGINEERING↗
DOE OSTI2019

Water Processing for Isotope Recovery Using Porous Zero Valent Iron

Reduction-oxidation cycles of metals can be harnessed to create a reusable tritiated water processing system. The concept is straightforward; a tritium-contaminated steam passes over a hot metal bed converting the metal to a metal oxide and liberating hydrogen isotopes for further processing and isotope separation. The bed is regenerated by converting the metal oxide back to a bare metal using protium gas, creating a clean water stream. Free oxygen is not produced during the cyclical process, making it safe for use in a hydrogen processing facility, and the only by-product is detritiated water. Porous zero valent iron (p-ZVI) has been identified as an ideal candidate material for this process due to its low cost, unique morphology, and favorable thermodynamics. Therefore, investigations of p-ZVI were conducted to better understand how a bed composed of such material would behave in a tritium processing facility. The thermal and physical properties were assessed, along with cycling and isotope effects. The results indicate that p-ZVI beds could serve as a low-cost, reusable system for the treatment of water in tritium processing facilities.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2019

Future Recovered Gas Dryer Development

Building on our successful development of a water detritiation process, this project was extended to ammonia detritiation using a catalytic isotope exchange process with hydrogen (H 2 ) for the next generation of RGD materials. In these processes, isotopic exchange between flowing H 2 with adsorbed tritiated species is facilitated by trace amounts of an active catalyst component (e.g. Pt) that is loaded onto a zeolite. Since the catalyst loading may alter the zeolite pore size, Pt/zeolite performance for moisture and ammonia adsorption underwent verification in addition to characterization of the remediation process. The performance was evaluated for catalytic isotope exchange of deuterated water and deuterated ammonia (surrogates) with H 2 at ambient temperatures.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Future Recovered Gas Dryer Development (SR19009)

Recovered Gas Dryers (RDGs) remove tritiated moisture and ammonia from the recovered gas stream. As such, the RGD bed remained at elevated temperatures due to tritium decay heat. It is highly desired to remove or reduce the amount of tritium in the bed. Due to RGD limitations, a catalytic isotope exchange process with protium (H 2 ) is proposed for next generation RGD. This concept builds on our recent and successfully developed water detritiation process and extends it to ammonia detritiation.

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 OSTI2019

Tritium Extraction from Water

Tritiated water production is ubiquitous in facilities that handle tritium gas. Sources range from decontamination efforts, to the deliberate conversion of elemental tritium to tritiated water in processes that strive to reduce emissions to the environment, to gaseous effluents to the environment. At low concentrations, ranging from a few μCi/L to mCi/L, high throughputs are required to process the high-volume, low-activity water. Combined Electrolysis Catalytic Exchange (CECE) shows promise by offering high throughput, reliability, economic viability, and facile coupling to isotopic separation systems if necessary. This paper will discuss the features of two production-scale CECE facilities: a 7-m 3 /h throughput system that uses an alkaline electrolysis cell and a 21-m 3 /h throughput system that uses a proton exchange membrane (PEM) electrolysis cell. Finally, the former is in service and has been modified to improve reliability; the latter is in the initial stages of commissioning.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗