(2020). Foreword: Selected papers from the 2019 Nuclear and Emerging Technologies for Space Topical Meeting (NETS 2019) Nuclear Technology: Vol. 206, Selected papers from the 2019 Nuclear and Emerging Technologies for Space Topical Meeting (NETS 2019), pp. iii-iii.

Nuclear thermal propulsion (NTP) could be an advanced technology to facilitate a new and excellent rocket engine that would at least double the performance of the best conventional chemical rocket engines. NTP has been under development for several decades and was selected as the leading candidate technique for the manned mission to Mars, as suggested in Design Reference Architecture 5.0. During development

The specific mass (or mass per unit power) is a fundamental performance metric in space power systems. For surface power, a low specific mass reduces launch costs and lander size. For nuclear electric propulsion, a low specific mass enables fast transit within the solar system. Studies on specific mass have typically focused on point designs and have not adequately explored the design space and scaling

This paper considers the issues of safety assessment of new nuclear power plant (NPP) projects with VVER Generation III+ reactors in relation to the probability target for large release, which is subject to verification in the development of a full-scale Probabilistic Safety Assessment (PSA) Level 2. The design solutions implemented in Generation III+ reactors allow reducing the probability of a severe

The Consortium for Advanced Simulation of Light Water Reactors is developing the Virtual Environment for Reactor Applications (VERA), and the MPACT code, which is the primary deterministic neutron transport solver in VERA, provides sub-pin level flux and power distributions as part of full-scale cycle depletion and analysis. In such calculations, an important aspect is the radial reflector treatment

Extension of the operational lifetime beyond 40 years is currently a noteworthy project in the field of nuclear safety in France, especially for 900-MW(electric) reactors that will be the first ones to go through the fourth periodic safety review. For 1300-MW(electric) reactors, the safety studies have already been engaged. Probabilistic Safety Assessments (PSAs) play an important role in this process

(2020). Foreword: Selected papers from the 2019 American Nuclear Society Student Conference. Nuclear Technology: Vol. 206, No. 7, pp. iii-iii.

The General Electric (GE®) PETtrace 860 cyclotron at the Missouri University Research Reactor (MURR) facility is used extensively for medical and research radioisotope production. However, no model exists of its performance, and the proton beam’s energy and spatial distribution are unmeasured. Here, an MCNP6 model was developed to improve upon the performance of the cyclotron target systems that are

(2020). Statement of Retraction: Visualization and Integration of Images of Radioactive Substances as Point Cloud Data in 3-D Environment Models. Nuclear Technology: Vol. 206, No. 7, pp. 1095-1095.

The electrochemical behavior of La2O3 was investigated in LiF-NaF-KF (FLiNaK, 46.5-11.5-42.0 mol %) eutectic at 700°C. In the electrochemical tests, two kinds of working electrodes, i.e., tungsten and graphite, were utilized. The present study showed that La3+ ions can be deposited in the form of La metal on a tungsten cathode or LaC2 on a graphite cathode, and O2− can be removed in the form of CO/CO2

In this paper, a set of stylized numerical benchmark problems is developed. These problems are based on the Oak Ridge National Laboratory preconceptual design of a fluoride-salt-cooled small modular advanced high-temperature reactor, or SmAHTR, that uses prismatic fuel assemblies with cylindrical pins/rods containing tri-isotropic fuel particles. A detailed description of the benchmark problems is

A new type of low-enriched uranium (LEU) fuel based on an alloy of uranium and molybdenum is expected to allow the conversion of U.S. domestic high-performance research and test reactors requiring high density fuel from highly enriched uranium (HEU) to LEU. The University of Missouri Research Reactor (MURR®) has undergone design and performance calculations for conversion to this LEU fuel. Presented

This study investigates the degradation of the heat transfer performance of a closed-circuit intermediate natural circulation heat transport loop used as a passive safety system in a nuclear power plant (NPP). The degradation arises from the strong thermal-hydraulic (TH) coupling of the loop operating characteristics, saturation temperature and pressure, and natural circulation flow rate, which determine

The pressurizer of a pressurized water reactor (PWR), as a spray-heating degasser, has been widely used to remove dissolved gas in the primary coolant of PWRs. In the real degassing process, the boundary conditions of the pressurizer may change, causing fluctuations in the degassing state and affecting the efficiency of degassing. However, open-published studies have focused mainly on the steady-state

Abstract In the event of a severe nuclear accident, one major concern is the release of radioactive material into the environment causing potential exposure of the general public to radiation. Among the volatile radionuclides are a range of tellurium isotopes. Due to the radioactivity and the volatility of tellurium, it has to be taken into account when assessing the overall effects of an accident

The standard approach in nuclear criticality safety analysis is to rely quite heavily—and in some cases exclusively—on passive controls, such as assuming all worst-case conditions are by default attained. This means assumptions are made such as no poison, optimum moderation, and pure fissile actinide content at the maximum mass with optimum full reflection. What is clearly attainable is something less

To study the burnup features of accelerator-driven subcritical systems (ADSs), simplified transmutation trajectories are imperative to make the simulation process more effective with acceptable precision. This process has long been considered a challenging task since the construction of simplified burnup chains often need complex judgments and experiences. Additionally, the burnup analysis of ADSs

During a severe accident in a nuclear reactor, there are a number of phenomenological events that can present a challenge to containment integrity. These include the generation and combustion of hydrogen, energetic fuel-coolant interactions, thermal attack of fission product barriers, core-concrete interactions, direct containment heating, and gradual overpressurization. The advanced design of the

The temperature field in a nuclear waste repository is an important issue with regard to the design and safety assessment of the repository. In this paper, a double-layer model for simulating the heat conduction near a single waste canister is established, and then, by applying the Laplace transform to the governing equations of the heat conduction in the buffer layer and the surrounding rock, the

Abstract The present U.S. nuclear fuel cycle faces challenges that hinder the expansion of nuclear energy technology. The U.S. Department of Energy identified four nuclear fuel cycle options that make nuclear energy technology more desirable. Successfully analyzing the transitions from the current fuel cycle to these promising fuel cycles requires a nuclear fuel cycle simulator that can predictively

Molten salts have been proposed as heat transfer media due to their superior thermal performance at elevated temperatures. A number of heat transfer correlations have been proposed in the literature for molten salts without explicitly considering the radiative heat transfer effect in the salts, which may not be negligible. This study therefore attempts to (1) quantitatively analyze the convective and

For several decades, extensive research has been performed on the recovery and purification of zirconium from spent nuclear fuel cladding using a variety of chlorination reaction processes. After the reaction between fuel cladding and chlorine gas, zirconium tetrachloride is separated from other chloride species based on their boiling/sublimation points; however, the presence of iron and niobium chloride

In order to develop a flow sheet for the purification procedure of a LiCl-KCl eutectic mixture with the underlying aim of avoiding Cl2 handling in an engineering-scale laboratory, the present work focuses on electrochemical investigations on vacuum dried eutectic mixtures LiCl-KCl + H2O and vacuum dried LiCl-KCl + H2O mixtures using cyclic voltammetry at 500°C. Complicated voltammetric features were

A whole-core, steady-state, thermal-hydraulic model for the cylindrical pin-type fluoride-salt-cooled small modular advanced high-temperature reactor (SmAHTR) is developed. In this preconceptual reactor design initially proposed by Oak Ridge National Laboratory, each fuel assembly in the graphite-moderated core has the FLiBe coolant flowing parallel to a hexagonal array of fuel and moderator pins.

A methodology for designing a Bonner sphere spectrometer was proposed based on the singular value decomposition (SVD) and information entropy theory. First, features of Bonner spheres were classified based on SVD, and then, the rationality of the selected spheres was analyzed. Second, the information entropy is used as the quantitative evaluation standard; combined with the unfolding method, the contribution

In the framework of the European Union MAXSIMA project, the safety of the steam generator (SG) adopted in the primary loop of the Heavy Liquid Metal Fast Reactor has been studied investigating the consequences and damage propagation of a SG tube rupture event and characterizing leak rates from typical cracks. Instrumentation able to promptly detect the presence of a crack in the SG tubes may be used

At the beginning of the last decade, Petascale supercomputers (i.e., computers capable of more than 1 petaFLOP) emerged. Now, at the dawn of exascale supercomputing, we provide a review of recent landmark simulations of portions of reactor components with turbulence-resolving techniques that this computational power has made possible. In fact, these simulations have provided invaluable insight into

The Argonaut reactor is a water-moderated research reactor that was designed by the Argonne National Laboratory. There are currently few reactors of this type under operating conditions in the world, one of which, located at the Nuclear Engineering Institute in Brazil, has been in operation since 1965. This study analyzes a nonpostulated accident caused by the collision of the reactor coverer into

A proton therapy facility based on an isochronous superconducting cyclotron is under constructed at the Proton Therapy Facility of the Huazhong University of Science and Technology. Due to the limitation of minimum energy extracted by the energy selection system in the upstream beamline, a range shifter is installed at the end of the nozzle to further decrease the proton beam energy so that the shallow-seated

Analytical solutions for temperatures in an infinite region bounded internally by a cylinder have proved to be useful for thermal analysis of heat-producing nuclear waste disposal scenarios where the thermal design criteria are peak temperatures. The practicality of an analytical solution for the temperature of the host rock used in forced-ventilation thermal analyses has been illustrated by a computational

The optical properties of FLiBe salt in a Fluoride-Salt-Cooled High-Temperature Reactor (FHR) present an opportunity to utilize Cerenkov radiation measurements to reconstruct the power profile in the core and detect various anomalies that could occur during operation. The Cerenkov light produced within a coolant channel is strongly correlated to the fission rate density and power level in the surrounding

Abstract In-vessel melt retention (IVMR) is a promising strategy in severe accident management for light water reactors. This strategy is not only adopted in the VVER 440 or AP600 reactors, but also included in higher-power reactors around 1000 MW(electric), like the AP1000 and Chinese CPR 1000. There is still a large uncertainty of IVMR by external cooling at powers higher than 1000 MW(electric),

In order to model the activated isotopes and resulting dose from a nuclear detonation in an urban environment, the Activation and Transmutation of Isotopes in an Unstructured Mesh (ACTIUM) Python toolkit has been developed to combine the unstructured mesh–based particle transport capability of MCNP6.2 with the CINDER2008 transmutation code to produce quantities of interest for the post-detonation nuclear

Airborne contaminants from fires containing nuclear waste represent significant health hazards and shape the design and operation of nuclear facilities. Much of the data used to formulate DOE-HDBK-3010-94, “Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities,” from the U.S. Department of Energy, were taken over 40 years ago. The objectives of this study were

A manual approach to radiography process optimization is a time-consuming and labor-intensive process. Therefore, a virtual environment in which all of the processes of optimization for a desired radiography experiment or setup are conducted is highly desirable. Such an environment should be able to provide the capability to arrive at radiographic scanning parameters that are optimized to within preset

Recent research has focused on the development of surrogate models for radiation source localization in a simulated urban domain. We employ the Monte Carlo N-Particle (MCNP) code to provide high-fidelity simulations of radiation transport within an urban domain. The model is constructed to employ a source location ( x , y , z ) as input and return the estimated count rate for a set of specified detector

The Sallen-Key filter is frequently used to realize radiation detector pulse shaping. To improve the performance of the digital pulse-shaping algorithm, we establish the full parameter Kirchhoff’s Current Law equations of the analog Sallen-Key circuit. Synthesizing these equations, a second-order nonhomogeneous difference equation is obtained. By analyzing the symmetry degree of the response function

Natural convection systems are a promising method to passively remove heat from reactor cavities during loss of forced flow accident scenarios. At Argonne National Laboratory (ANL), a highly instrumented Natural Convection Shutdown Heat Removal Test Facility (NSTF) was used to demonstrate the effectiveness of air-cooled natural convection systems. In previous work, RELAP5-3D simulations were performed

Abstract Energy markets are changing because of (1) the addition of nondispatchable wind and solar electric generating capacity and (2) the goal of a low-carbon energy system. The large-scale addition of wind and solar photovoltaics results in low wholesale electricity prices at times of high wind and solar output and high prices at times of low wind and solar input. The goal of a low-carbon energy

Credibility requires predictability. Nuclear power plant (NPP) construction projects tend to be large and expensive, sometimes with high cost overruns far beyond those that might have been expected or predicted due to usual and recognized uncertainties and variations (e.g., in labor and materials costs combined with multiyear duration and complex construction logistics). This unaccounted for uncertainty

The transuranic (TRU) ingot is considered to be the most prominent target material of pyroprocessing in terms of safeguards since it contains almost all of the Pu of the feed spent fuel. Due to the high density, excessively high neutron emission rates, and high neutron multiplication of the U/TRU ingot, it is impractical to apply gamma-ray spectroscopy or neutron coincidence counting techniques to

This paper aims to revise the critical flow criterion and flashing inception of the analytical critical flow model and to further explore the effect of upstream conditions on critical mass fluxes. The flashing inception of the model is considered to be affected by the Reynolds number and the Jakob number. Model predictions show strong similarities with test results compared with other models, with

A radioactive corrosion product, Chalk River unidentified deposit (crud) was sampled and analyzed using an electron probe micro-analyzer with zinc-injected spent nuclear fuel rods (HU Unit 1, actual burnup 49 655 MWd/tonne U). Hot-cell facilities, a space for handling highly radioactive materials, were used as a way to collect crud deposited in the fuel rod cladding tube at a specific location of the

The Korea Atomic Energy Research Institute (KAERI) has developed the Core Reliable Optimization and thermofluid Network Analysis (CORONA) code for core thermofluid analysis of a prismatic high-temperature gas-cooled reactor (HTGR). KAERI performed scaled-down standard fuel block (SFB) heated tests at a helium experimental loop to validate the CORONA code. The scaled-down SFB was designed based on the

The containment of a nuclear reactor is a component whose loss in an accident has serious consequences on property, persons, and environment. The Fukushima accident reminded us of this reality. For more than 30 years, the French Nuclear Energy and Alternative Energies Commission has been conducting research on the failure modes of these enclosures, particularly on their slow pressurization during a

The digital control system (DCS)+state-oriented procedure (SOP) system adopted by China’s Ling’ao Phase II nuclear power plant’s main control room requires changes to the cognitive process, behavior mode, and error mode while triggering new human factors. Therefore, in this paper we present a cognitive reliability model for the DCS+SOP system in the Ling’ao Phase II Nuclear Power Plant’s main control

Human error has been highlighted as main cause of industrial and nuclear accidents. One of the key issues related to human error is a worker’s fitness for duty (FFD). FFD refers to the mental and physical ability of employees to safely perform their job. The objective of this study is to investigate the feasibility of identifying a worker’s FFD status using biosignals. The FFD statuses examined were

The Organisation for Economic Co-operation and Development (OECD)/Nuclear Energy Agency (NEA) Benchmark Study of the Accident at the Fukushima Daiichi Nuclear Power Station (BSAF), which started in 2012 and continued until 2018, was one of the earliest responses to the accident at Fukushima Daiichi. The project, divided into two phases, addressed the investigation of the accident at Units 1, 2, and

As one of the lessons learned from the Fukushima Daiichi accident, long-term station blackout (SBO) and subsequent loss of ultimate heat sinks have prompted discussion on this topic in the nuclear industry. The SBO sequences for a Westinghouse three-loop pressurized water reactor (PWR) have been under investigation for a long period. To cope with the long-term SBO issue, many nuclear power plants have

Abstract Electrochemical reprocessing (also commonly known as pyroprocessing) of used nuclear fuel is an alternative to aqueous reprocessing that confers a number of advantages, including the ability to process more recently discharged fuel, smaller resultant waste volumes, and the lack of isolation of plutonium in the product stream. While electrochemical reprocessing systems have seen a significant

The National Aeronautics and Space Administration (NASA) Radioisotope Power Systems (RPS) Program Mission Analysis Team at the Jet Propulsion Laboratory (JPL) requested a JPL Innovation Foundry Architecture Team (A-Team) study to assess mission pull for small RPS [1 to 40 W(electric)] and define the focus of future power system developments required to enable small RPS missions. The A-Team is JPL’s

The leaching behavior of cerium and cesium from different mixtures of rapid setting cement (RSC) with deionized water (DIW) and artificial seawater (ASW) under both dynamic and static leach conditions was investigated according to the method in American National Standard ANSI/ANS-16.1-2003. The leachate solution was collected, diluted with HNO3, and analyzed using inductively coupled plasma–mass spectrometry

TerraPower participated in a cooperative project among industry, a national laboratory, and a university to perform verification and validation of computational fluid dynamics (CFD) methods for predicting the flow and heat transfer within fuel assemblies with hexagonally packed wire-wrapped fuel pins. This project consisted of both experimental and numerical components and used surrogate fluids and

Membranes have been widely used in low-level radioactive wastewater (LLRW) treatment and are under irradiation as a result of radioactive nuclides present in the wastewater, which may cause damage to the membranes and weaken their performances. Irradiation-induced material property changes of several organic membrane matrices and modifiers at different gamma irradiation doses were investigated in this

We, the American Nuclear Society, the Editor and Publisher of Nuclear Technology, have retracted the following article: Yuki Sato & Tatsuo Torii: Visualization and Integration of Images of Radioactive Substances as Point Cloud Data in 3-D Environment Models. Nuclear Technology, 2020, DOI: 10.1080/00295450.2020.1722555 The authors have requested the retraction of their article due to an identified defect

The Transient Reactor Test (TREAT) Facility is a graphite reactor capable of delivering tailored power histories to unique experiment designs. Frequently, these experiments are designed to simulate a specific reactor transient to perform detailed studies of reactor fuel behavior. The reactor core is uniquely designed to allow a limited energy release and resulting peak fuel cladding temperature such

To respond to seismic and other natural hazard events, designers of the Japan Sodium-cooled Fast Reactor (JSFR), an advanced loop-type reactor, are planning to adopt a steel-plate reinforced concrete structure reactor building and an advanced seismic isolation system to strengthen this building. The design changes have been initiated by lessons learned from the Fukushima Daiichi nuclear power plant

Using the Laplace transform for solving a two-region (cladding/liquid) conduction problem with an exponentially increasing heat flux boundary condition, an analytic temperature profile has been found. The rate of the temperature increase in the second region (liquid) is used to determine energy deposition in the thermal boundary layer of the liquid. Energy deposition rates are then compared to the

In recent years, the compound beyond-design-basis accident (BDBA), which combines earthquake, tsunami, or some other severe events to impact a nuclear power plant (NPP), has received more attention. After the Fukushima nuclear disaster, the licensee of NPPs in Taiwan established the ultimate response guideline (URG) that instructs operators to perform reactor depressurization, low-pressure water injection

The future of human exploration missions to Mars is dependent on solutions to the technology challenges being worked on by the National Aeronautics and Space Administration (NASA) and industry. One of the key architecture technologies involves propulsion that can transport the human crew from Earth orbit to other planets and back to Earth with the lowest risk to crew and the mission. Nuclear thermal