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At least 541 records · Page 30
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Investigating the impacts of used nuclear fuel direct dissolution on the radiolytic longevity of solvent and butyramide extractants

Removing the nitric acid (HNO3) dissolution step in used nuclear fuel (UNF) reprocessing would reduce the volume of radioactive waste streams generated, thereby, improving process efficiency. A promising strategy for this is the direct dissolution of UNF that has been pretreated by voloxidation into an organic solvent composed of specialized extractants and diluent. However, removal of the aqueous HNO3 phase from the envisioned reprocessing system has the potential to drastically change the suite of radiation-induced processes occurring, and thus, alter the longevity of proposed reagents. Furthermore, the impacts of fission product and transuranic metal ion complexation on the aforementioned radiation-induced processes is poorly understood, and yet can cause significant changes in radiolytic longevity. To bridge these knowledge gaps and support the continued development of direct dissolution strategies, we present an investigation into the impacts of direct dissolution conditions on the gamma radiation-induced degradation of N,N-di-(2-ethylhexyl) butyramide (DEHBA) and N,N-di-(2-ethylhexyl)isobutyramide (DEHiBA) ligands—candidate replacements for tributyl phosphate—in pre-equilibrated n-dodecane solvent in the presence and absence of envisioned loading amounts of uranium.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2021

Gas-phase stability of large lanthanide:diglycolamide clusters evaluated using collision-induced dissociation

Efficient utilization of long-term deep geologic storage repositories is critical for the large-scale deployment of nuclear energy. As the minor actinides (americium and curium) are the largest contributor to the decay heat of used nuclear fuel after a few hundred years, their removal from used fuel prior to disposal can significantly increase the amount of waste that can be stored in a given volume. The development of ligands that can effectively separate the minor actinides from other components of used nuclear fuel are crucial to efficient utilization of geological storage repositories. N,N,N’,N’-tetraoctyl diglycolamide (TODGA) is a promising extractant for the separation of lanthanides and the minor actinides from other components of used nuclear fuel. While the use of TODGA in f-element separations has been investigated in process-based formulations, gas-phase metal ion cluster experiments enable the study of covalent interactions in reprocessing systems absent from solvent effects. Exploring fundamental differences in lanthanide-ligand covalent interactions can impact the development and implementation of actinide-lanthanide separation systems in nuclear fuels reprocessing. In this study, lanthanide-TODGA clusters were synthesized in the gas-phase and identified using mass spectrometry fragmentation experiments. Large europium and samarium clusters were identified that contained up to 8 and 10 bound TODGA ligands, respectively; this was surprising due to the size and multidentate binding that is normal for TODGA. In addition, while smaller clusters showed evidence of sequential ligand fragmentation, larger clusters displayed the loss of neutral TODGA with applied collision voltage. Interestingly, the voltage required for this removal decreased as more TODGA ligands were bound to the metal, suggesting that the metal coordination sphere was becoming more saturated and TODGA ligands were more weakly bound as the clusters got larger.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2025

Investigating Radiation-Induced Actinide Species in Solution

Used nuclear fuel (UNF) separation techniques that strive to separate radiotoxic americium (Am) from trivalent lanthanide fission products through oxidation state control have increased research efforts surrounding Am(V) and Am(VI). However, equivalent knowledge of the tetravalent state, Am(IV), has remained elusive, particularly in conditions more representative of UNF reprocessing, i.e., in concentrated nitric acid (HNO3). With this in mind, we have used electron pulse radiolysis to study the radiation-induced redox reaction of Am(III) with the oxidizing nitrate radical (NO3?) in 6 M HNO3: Am(III) + NO3? ? Am(IV) + NO3? . These experiments enabled us to observe the growth and decay of Am(IV) in a concentrated acidic solution for the first time. The transient Am(IV) species was found to have a lifetime of ~16 µs?sufficiently long-lived to play a critical mechanistic role in UNF reprocessing systems. Additionally, we performed the first-ever temperature-dependent kinetics study of an actinide element, elucidating unprecedented Arrhenius and Eyring activation parameters for the reaction of Am(III) with NO3?. This new knowledge provides much-needed molecular-level insights into the radiation-induced behavior of Am.

actinide↗
DOE OSTI2024

Acoustic Measurements of Solvent Extraction Processes in Support of Safeguards

The proposed poster focuses on using acoustic monitoring to advance detection techniques for reprocessing equipment in support of nuclear safeguards. The usage of free air acoustic monitoring has been previously demonstrated at Idaho National Laboratory (INL) at facilities such as the Advanced Test Reactor and the National Security Test Range. However, this work focuses on a deployment environment dedicated to monitoring separation processes, using solvent extraction equipment such as centrifugal contactors. This environment offers an opportunity for signal discovery and in characterizing acoustic signatures of the equipment in operation. This data can support the development of safeguards by design and security by design measures for aqueous reprocessing facilities. Furthermore, this type of monitoring can aid in early detection and identification of removed materials indicating diversion, which is essential for initiating material recovery and actor identification. The results of this work include data from nine low-frequency acoustic sensors used to investigate potential acoustic characteristics of centrifugal contactors used in multi-stage processes. The results also discuss the correlation between the signatures and the operation of the contactor banks.

98 - NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL↗
DOE OSTI2024

Dodecane Radiolysis Yields by Time-Resolved and Steady-State Methods

Liquid organic molecules are present as solvents, complexing ligands, and additives in both used nuclear fuel reprocessing solvent systems and in their subsequent nuclear waste streams. Under these extreme environments, these organic molecules are constantly exposed to ionizing radiation which promotes their radiolysis, forming a variety of short-lived, highly energetic, excited state and radical species.1-4 Here, we demonstrate new experimental results for the steady-state and time-resolved irradiations of dodecane (C12H26), a long chain, liquid, aliphatic hydrocarbon that is the prototypical solvent used for benchtop studies of aqueous-organic solvent extraction systems. When ionizing radiation interacts with neat dodecane, the energy transfer can result in molecular ionization, to give the dodecane radical cation (C12H26+•) and the solvated electron (eS–), and molecular electronic excitation (C12H26*), which rapidly produces transient carbon-centered radical fragments (CxHy•) and hydrogen atoms (H•).1-4 Studies on the initial yields of the ionization and excitation products were performed using time-resolved picosecond electron pulse radiolysis with the use of molecular probes. Using steady-state cobalt-60 gamma irradiations, the suite of products formed by dodecane radiolysis in aerated and deaerated solutions was determined. Then, using iodine as an alkyl radical scavenger, the loss of molecular iodine with dose was quantified, and by correlating with the molecular hydrogen yields of the system, the initial yields of the various carbon-centered radicals were also determined. Finally, the rates of reactions of the C12H26+• and eS– with ligands proposed for use in spent nuclear fuel reprocessing were studied as a function of temperature from 10 – 40 °C.

38 - RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCL↗
DOE OSTI2023

Thermodynamic modeling of KCl-PrCl 3 and KCl-LiCl-PrCl 3 systems

Molten salt electrolysis can recover the actinides from spent nuclear fuels, and it involves a eutectic LiCl-KCl in molten form as an electrolyte. During reprocessing, the concentration of fission products such as La, Nd, Pr, etc., increases and affects the recovery efficiency of the electrolyte. In this work, thermodynamic modeling of KCl-PrCl 3 and KCl-LiCl-PrCl 3 systems was carried out using the CALPHAD (Calculation of Phase Diagrams) approach for the first time. The thermodynamic functions for the pure salts were taken from the SGTE (Scientific Group Thermodata Europe) Substances (SSUB) database. The experimental thermochemical and phase equilibria data available in the literature were used as input for the assessment of KCl-PrCl 3 and KCl-LiCl-PrCl 3 systems. The model parameters for the KCl-LiCl system were adjusted to include the new Gibbs energy descriptions for the pure salts. In addition, the sublattice model for the liquid phase in the LiCl-PrCl 3 system was modified and reassessed to ensure the model compatibility for higher-order extrapolation. There is a good agreement between the experimental and calculated thermochemical and phase diagram data for all the optimized constituent binaries and the ternary system. Furthermore, this work will be beneficial for determining the solubility limit of PrCl 3 in molten LiCl-KCl electrolytes and their thermodynamic properties for improving the efficiency of the pyrochemical process.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2018

Fallon FORGE: Seismic Reflection Profiles

Newly reprocessed Naval Air Station Fallon (1994) seismic lines: pre-stack depth migrations, with interpretations to support the Fallon FORGE (Phase 2B) 3D Geologic model. Data along seven profiles (>100 km of total profile length) through and adjacent to the Fallon site were re-processed. The most up-to-date, industry-tested seismic processing techniques were utilized to improve the signal strength and coherency in the sedimentary, volcanic, and Mesozoic crystalline basement sections, in conjunction with fault diffractions in order to improve the identification and definition of faults within the study area.

15 GEOTHERMAL ENERGY↗
DOE OSTI2016

Performance Criteria for Capture and/or Immobilization Technologies

The capture and subsequent immobilization of the four volatile radionuclides ( 3 H, 14 C, 85 Kr, and 129 I) from the off-gas streams of a used nuclear fuel reprocessing facility has been a topic of substantial research interest for the US DOE and international colleagues. Regulations set forth by the US EPA direct that some or all of these radionuclides (based upon fuel burnup, fuel type, cooling time, etc.) will require removal, to some extent, from the plant effluent streams prior to discharge to the environment. Upon removal, the radionuclide, as well as any associated sorbent, is destined for waste. Research of separation and capture methodologies has included a wide range of technologies including liquid caustic scrubbing systems, solid adsorbents, and cryogenic distillation. The studies of waste forms have been correspondingly diverse. In considering the technologies available for future development and implementation of both sorbents and waste forms, it will be necessary to use benchmarked measures of performance to objectively evaluate each sorbent system or waste form. This document is intended to provide initial guidance on the types of performance criteria for capture materials and waste forms intended for use in the recycling removal and disposal of UNF and, where possible, the minimum acceptable values for those criteria.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2017

Progress, Performance, and Prospects of Ultra-High Resolution Microcalorimeter Spectrometers

In 2005 the LANL/NIST team used a single high-resolution microcalorimeter detector to measure the gamma-ray spectrum of a plutonium sample. After more than a decade of research and development on this topic, both the technology and our general understanding of its capabilities have advanced greatly, such that a progress review is now timely. We examine the scenario of a large-scale reprocessing plant and conclude that current non-destructive analysis (NDA) methods are inadequate to safeguard such a facility to the desired levels, leading to undesirable dependence on massspectrometry (MS) destructive analysis (DA). The development of microcalorimeter detectors is intended to close the performance gap between NDA and DA methods to address the needs of nuclear facilities.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2015

Radioactive waste management in France: taking-up present and future challenges - 15120

The reduction of the volume and radiotoxicity of radioactive waste has been one of the key drivers for the implementation of the French nuclear program. Interactions between the nuclear industry, the administration, the competent authorities and other stakeholders including the civil society has led to a continuous evolution of the industrial facilities, practices, solutions and products to move towards waste minimization. Bringing a solution to the management of ultimate radioactive waste is clearly a requirement for the sustainable development of nuclear energy whose crucial role in the world's future energy mix has been confirmed in the past few months by several international organizations. The first question to be answered concerns the definition of radioactive waste. This notion may be seen as self-evident. It is not. For example, used fuel is considered a High Level Waste in Finland or Sweden, but a recyclable material in countries including China, France, India, Japan, Russia, and the Netherlands. In France, a definition is provided by law to clarify this notion. Indeed, the 2006 French law concerning the Sustainable Management of Radioactive Materials and Waste stipulates that 'ultimate radioactive waste shall include any radioactive waste for which no further processing is possible under current technical and economic conditions, notably by extracting their recoverable fraction or by reducing their polluting or hazardous character'. Used fuel is thus reprocessed in order to reduce the final waste volume and long term radiotoxicity, while extracting value from the recovered materials. Even if the general approach and the processes may be common for waste management, it is important to clearly make the distinction between the wastes stemming from used fuel processing or conditioning (when considered as waste), the wastes generated through the operation of nuclear power plants and fuel cycle facilities, and the waste arising from the dismantling of nuclear installations. After a brief overview of the different types of waste stemming from nuclear power generation, this paper will review solutions and processes already implemented for their safe and efficient management. It will also practically illustrate the evolution of these processes and related facilities to further gain in efficiency, notably in terms of volume reduction; the related R and D outcomes will be addressed. It will also describe the upcoming challenges in this field and the envisioned solutions to respond to them; the efficiency, the completeness and consistency of these solutions with the currently considered global framework, based on a stepwise and long term approach from waste generation to disposal, will also be analyzed. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Laser size reduction of contaminated Magnox Pond skips - 15166

The Magnox Pond Program Team at Hinkley Point A Power Station have successfully demonstrated the use of an automated Computer Numeric Controlled (CNC) dry milling process to efficiently decontaminate radioactive pond skips that were once used to store and transport Magnox spent fuel assemblies between reactor sites and Sellafield for reprocessing. This decontamination process has ensured ILW skips meet metal melt recycling criteria, and even Out of Scope levels, while at the same time producing dry swarf that is easily disposed of as ILW. However, the dry milling method requires the skips to be size reduced to a very simple flat geometry to simplify the milling operation. Several size reduction techniques (mechanical and thermal) have been evaluated. Based on the advantages of remote handling, high cutting speed, flexibility with complex geometries, reduced secondary waste production and significantly reduced worker exposure, robotically operated fibre delivered laser cutting was chosen. This paper describes the development, installation and operation of an automated laser cutting system commissioned at Hinkley Point A to size reduce contaminated skips in to five flat sections. It was demonstrated that a complete skip can be remotely size reduced in less than 60 minutes. This successful demonstration, coupled with CNC milling, has the potential to save an estimated British Pounds 30 million across the Magnox sites alone, with much higher saving potentials for skips stored at Sellafield, enabling this new size reduction process to meet cost reduction objectives of the UK's Nuclear Decommissioning Authority. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Decommissioning Experience at Rokkasho; Standing Type Manipulator: A1000S for Dismantling Tasks - 16434

Decommissioning is a technical process which includes various steps and processes from the clean-up of radioactive materials to the progressive demolition of the plant. One of these steps is the cutting of subassemblies, like tanks, pipes or walls in small pieces suitable for the sorting and disposal. Different solutions are offered for this cutting work and can be grouped as following: - Chip forming - sawing, drilling, milling, turning etc. - Shearing - punching, stamping, scissoring. - Abrading - Grinding, lapping, polishing; water-jet. - Heat - flame cutting, plasma cutting, laser cutting. - Electro-Chemical - Etching, Electrical discharge machining (EDM). Each method has its limitations in accuracy, cost, and effect on the material. In 2013, Waelischmiller Engineering won a contract for two remote handling systems dedicated to the dismantling cell at Rokkasho Nuclear Fuel Reprocessing Facility in Japan. For this project, Inconel and other metals needed to be cut. One of the main cutting methods was decided to use of an angle grinder handled by a robotic arm. Because the use of the overhead systems (bridges and cranes) was difficult for this installation, it was determined, that the best alternative was a power manipulator A1000 installed on the floor with a pre-positioning system. The project proceeded to go forward with the adaptation of the standard A1000 with integration of a control system in a Cartesian coordinate frame; resulting in a heavy duty arm; A1000S with 6 degrees of freedom. The heavy duty power arm A1000S was developed and designed for mechanical cutting with an angle grinder, especially for thick and hard material for example stainless steel and Inconel. Cutting a thick material with an angle grinder requires repeatable precise linear motion, in order not to damage the disc. The angle grinder should be handled with a manipulator which can cut in all directions in a linear motion, since the objects which should be cut are usually very large and fixed in any direction For these requirements, the Cartesian control function was added to our standard power manipulator type A1000. In some cases, the decommissioning work includes repeated access routes or fixed access points that the manipulator arm has to pass repeatedly. For example a fixed point where the waste materials are collected, or repeated transport route that the arm has to go along for each step. For this requirement, the A1000S has been equipped with the 'Go To-Mode'. It is a 'teach and playback mode' which has been developed especially for remote operating manipulators. Quick direct teach, quick play function and an intuitive touch-panel layout are some of the features. With the Go To-Mode high working efficiency was achieved. After rigorous testing at Waelischmiller premises; the manipulator was delivered to JNFL in Rokkasho. It was found that the obtained functionality and precision can be applicable not only for the cutting with a disc grinder, but also the laser cutting method, which requires precise trajectory control. This paper will provide: - A project description, - Presentation of solution process, - Technical description of the A1000S, - Future Applications of the robotic Arm A1000S. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Gas Retention and Release from Nuclear Legacy Waste - 16449

The retention of gas within corroded magnox sludge waste at Sellafield, UK and secondary reprocessing waste at Hanford, USA has significant economic and safety implications for decommissioning various nuclear legacy buildings, including the magnox swarf storage silos and first generation magnox storage pond. A series of laboratory scale gas retention tests within magnesium hydroxide soft sediments have revealed a 4-51 Pa yield stress range where consolidated beds could retain sufficient gas to become buoyant with respect to a water supernatant. Density inversion could lead to a Rayleigh-Taylor style instability which could result in an upward transfer of radioactive material from the consolidated bed. The applicable yield stress range suggests that such rollover events may occur in weaker sediment than previously hypothesized, based on current understanding of the fluidization and stable channel mechanisms for gas release from weak and very strong sediments respectively. X-ray computed tomography images of gas retained by 7 Pa yield stress soft sediment reveal both a stable foam layer at the top of the bed and regions dense with micro-bubbles which could provide pathways for gas transport through the bed. Extension of these pathways, hidden below the surface of the sediment, to the container walls and the foam layer could represent a novel mechanism for gas release from intermediate strength sediments of <100 Pa yield stress. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Robotics for Nuclear Monitoring and Inspection - 18029

As a greater number of the world's nuclear facilities approach the end of their planned lifetime and enter the decommissioning and dismantling phase, a greater impetus than ever is being placed on the use of novel technologies to assist in this otherwise extremely lengthy, complicated and costly process. Being host to numerous first-generation plants, as well as the Sellafield Limited nuclear reprocessing facility, the UK is now requiring the use of a range of robotic systems and is well-placed to act as a test-bed for the deployment of these platforms. Presented in this work is the overview of the wide range of robotic research that is occurring at the University of Bristol. Not limited to ground-based platforms - those developed at the University Bristol,UK, include; airborne, underwater as well as pipeline network monitoring systems. Through the application of each of these robotic systems, not only is the dose-rate otherwise experienced by the operator removed, but the costs associated with the work are also significantly reduced, as well as the speed at which it is performed dramatically increased. All the systems descried in this work have been successfully deployed at one (or multiple) nuclear sites, with the results used to inform further decommissioning - typically within environments previously uncharacterised due either to their inaccessibility or high levels of radioactivity. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2018

The Strategic Benefit of Self Shielded Boxes for Storage and Disposal of Metallic Uranic Material-18141

Sellafield Ltd, on behalf of the Nuclear Decommissioning Authority (NDA), is responsible for the management of a number of facilities whose inventories include a range of metallic uranic material. Additional fuel and fuel bearing materials exist in the NDA estate, some of which are similar to the Sellafield-managed inventory and others present different management challenges. Whilst UK Government policy directs that some of these materials are assets and are therefore managed with eventual future use in mind, there remains a large quantity of material, principally either out-of-scope for reprocessing or which derives from legacy facilities, which is likely to be disposed of to a future Geological Disposal Facility (GDF). The majority of this material is stored under wet conditions to facilitate dose shielding and heat dissipation and will therefore require removal from wet storage, consolidation and conditioning, prior to transfer to GDF. In order to accelerate high hazard and risk reduction by sooner retrieval of legacy material from wetted storage, one of the legacy storage facilities has led technical work to develop the design of Self Shielded Boxes (SSBs) and to substantiate their use for interim storage of the materials in question. Use of the SSBs would represent a change of strategy on the Sellafield Site: historically, timescales for retrieval of material have been reliant upon a waste treatment and storage/disposal route being available. SSBs provide the opportunity to retrieve uranic materials from aging legacy storage facilities for immediate buffer storage, by decoupling the timing of retrieval from the availability of an onward route. An understanding was required of the scope for defining optimal routes for each metallic uranic fuel and fuel bearing material group for safe transport and storage commensurate with current final disposal assumptions and risks, taking into account international best practice. A study is underway to understand options for transfer of material into SSBs, buffer/interim storage locations, treatment/conditioning processes and transport to the GDF. This work forms the basis of a prioritised road-map for the development of routes for study material groups aligned with ongoing and existing planned technical work, which is a pre-requisite to strategy development. The ultimate output of the study will be identification of full life cycle management strategies for metallic uranic material from an enterprise perspective. The combination of this strategic work and ongoing technical work will underpin a series of decisions to divert sub-groups of uranic material away from currently assumed baseline routes in support of earliest practicable hazard and risk reduction. Hence, each decision will reduce the scope of a placeholder future uranic fuel treatment capability, which will diminish the associated British Pound 1 bn capital cost. To date, a technical case for interim storage of uranic material in SSBs has been substantiated for around two thirds of the study materials. The requirement for a new strategy at Sellafield was driven by technical development of SSBs in response to the needs of one programme, but this prompted the study into the potential utilisation of SSBs in order to derive benefit for the wider enterprise and across the NDA estate. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Recovery from feeding unconditioned feed to part of the solvent extraction process in Thorp - 14430

A recent event in the Thorp Reprocessing Plant involved unconditioned feed being sent to one of the main process solvent extraction vessels. As the feed was unconditioned the fissile material was lost to the aqueous raffinate stream. The plant was tripped and shutdown in line with the baseline criticality safety case. This paper describes the recovery option that was taken to remove the Pu from the raffinate tank and safely consign it to the downstream effluent vessels. Key assumptions that were fundamental to maintaining criticality safety throughout these operations were clearly highlighted in the supporting criticality safety assessment. Key learning points that are of relevance to the wider criticality safety assessment community are pulled out at the end of this paper. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2017

{sup 14}C Entry into the Atmosphere

{sup 14}C enters the atmosphere in amounts equivalent to 1.4 PBq/yr with total accumulation 140 PBq via cosmic radiation. As a result of nuclear explosions (1950–1969), its activity in the atmosphere exceeded 200 PBq. At present, {sup 14}C has been completely removed into bottom waters and sedimentary rocks in the ocean. The activity of the {sup 14}C entering the atmosphere from all operating nuclear reactors equals ~0.3 PBq/yr and the amount from all spent fuel reprocessing facilities equals ~0.06 PBq/yr. The admissible levels of {sup 14}C emissions must not exceed levels corresponding to peroral intake dose 10 μSv/yr. This is can be accomplished by means of a system of measures: reduction of the volume of technogenic gases and their {sup 12}CO{sub 2} content, combining high-efficiency purification with dispersion through high exhaust-stacks, and developing new technologies and reagents binding {sup 14}C in compact forms.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2024

Response of soil bacteria to PUREX chemicals suggests biomarker utility and bioremediation potential

Chemicals involved in plutonium uranium reduction extraction (PUREX) can be released from nuclear reprocessing facilities and accumulate in the environment. We exposed chemically diverse soils to a range of concentrations of key chemicals used in the PUREX process. The responses of soil microbial communities are dependent on soil type, and tributyl phosphate exposure generates the most reproducible changes in microbial communities. We reconstructed the genomes of key bacteria and find several phosphotriesterase genes found only in Rhizobiaceae. The abundance of phosphotriesterase genes is significantly higher in samples exposed to tributyl phosphate. In conclusion, these phosphotriesterase genes may be involved in breakdown of tributyl phosphate, and a means of accessing phosphate for these bacteria.

Bioremediation↗