MCNP - Science topic

Non-destructive gamma-ray analysis measurements are more cost-effective and time-efficient than destructive radiometric methods such as alpha spectrometry or mass spectrometry. This approach is also suitable for closed or unopened sources. Many gamma-ray spectrometry measurements utilize high-purity germanium (HPGe) detectors due to their superior...

Phthalates are widely used chemicals with ubiquitous human exposure. Evidence indicated that phthalate exposure was associated with an increased risk of aging-related diseases. Klotho is a transmembrane protein with anti-aging functions, and its association with phthalates remains unknown. To find the association between phthalate exposure and seru...

TRAMO is a Monte Carlo code which is specially designed for geometries of nuclear power plants. In recent years, TRAMO has undergone a number of technical developments. In addition to the conversion to modern Fortran, standardized models for VVER-440 and VVER-1000 for the evaluation of monitor experiments on the surface of the reactor pressure vess...

The assessment of the neutron flux distribution in nuclear power plant components, like reactor internals and the pressure vessel, is one of the most important parts of their residual lifetime evaluation process because the irradiation damage of these components is strongly dependent on it. The fast neutron fluences in power reactors are generally...

Due to Germany’s nuclear phase-out, decommissioning and final disposal of construction materials of Nuclear Power Plants (NPP) become increasingly important. The reliable determination of radionuclides produced by neutron activation, the activity as a function of time since shutdown and investigation of subsequent radionuclide mobility are subject...

The present paper summarizes the experience accumulated at the Laboratory for Reactor Physics and Thermal-Hydraulics (LRT) of the Paul Scherrer Institute in the field of reactor dosimetry, as well as outlines the recent progress achieved in relation to the associated nuclear data uncertainty propagation methodologies. For dosimetry simulations, the...

MCNP code provides numerous variance reduction techniques that are mainly used to optimize the analog Monte Carlo simulations. These techniques can reduce the statistical uncertainty of the simulation results while minimizing computational costs. Weight window is one such technique that is commonly used to optimize shielding calculations. However,...

An approach is described for estimating the excore source range detector count rate for several secondary neutron source configurations. A case in which a Westinghouse four-loop plant considered relocating the secondary source fuel assemblies and switching from secondary source fuel assemblies with six secondary source rods to assemblies with two o...

Boron Neutron Capture Therapy (BNCT) is expected to be a promising radiation therapy for cancer, and research on various issues associated with it is still in progress. One of the unsolved issues is the construction of a system for observing the effect of the treatment (local boron dose) in real time under high-background circumstances. Thus, we se...

This chapter presents a description of most of the instruments that are currently in use for the measurement of plutonium and uranium using passive methods (without an external source). This includes the acquisition electronics as well as Singles counting methods, coincidence counting methods and multiplicity counting methods. The Singles counting...

The ultra-cold neutron (UCN) source being commissioned at North Carolina State University’s PULSTAR reactor is uniquely optimized for UCN production in the former graphite-filled thermal column outside of the reactor pool. The source utilizes a remote moderation design, which is particularly well suited to the PULSTAR reactor because of its high th...

TRIPOLI-4® is a general-purpose Monte Carlo radiation transport code developed at CEA Paris-Saclay center. It uses continuousenergy nuclear data to simulate neutron transport for diverse nuclear engineering fields. Neutron multiplication calculations of subcritical systems are important for application areas including criticality safety, reactor ex...

Particle tracking Monte Carlo codes are complicated programs to use, making them error prone for the end user. To address this problem, and simplify the use of (initially) FLUKA, Flair was born in late 2006. Over the course of time, Flair evolved so much that it established itself as the de-facto standard for working with FLUKA, even to the extent...

The activation method used for the production of molybdenum-99 in the WWR-K reactor currently allows the maximum production of the specific activity of molybdenum-99 equal to (85 ± 11) GBq/g Mo as a result of seven-day neutron irradiation of natural molybdenum (VI) oxide. It is known that the reaction ⁹⁸Mo(n,γ)⁹⁹Mo is induced in the thermal region,...

The DD, TT and DT neutron streaming experiments (NEXP-STRE) in the fusion facility JET are here simulated with TRIPOLI-4® Monte-Carlo code. Specifically, we present the results from the simulation of the DD (2019) and the later TT and DT (2021) campaigns. The last version of TRIPOLI-4® code, developed by CEA, is provided with an innovative variance...

Quite often, detectors for measuring nuclear performance and radiation quantities of relevance in fusion experiments are requested to withstand harsh working conditions due to intense neutron and gamma radiation fields. High temperature constitutes a further harsh element in some locations of the machine, where it is necessary to perform some on-li...

The Ultra-Cold Neutron (UCN) source being commissioned at North Carolina State Universityâs PULSTAR reactor is uniquely optimized for UCN production in the former graphite-filled thermal column outside of the reactor pool. The source utilizes a remote moderation design which is particularly well suited to the PULSTAR reactor on account of its large...

To qualify for nuclear applications, materials must meet specific criteria, including mechanical properties, high-temperature behavior, corrosion resistance, and high-temperature oxidation resistance. High Entropy Alloys (HEAs) are particularly suitable for these applications due to their unique properties. Consequently, we conducted a theoretical...

A novel concept of cold neutron source employing chessboard or staircase assemblies of high-aspect ratio rectangular para-hydrogen moderators with well-developed and practically fully illuminated surfaces of the individual moderators is proposed. An analytic approach for calculating the brightness of para-hydrogen moderators is introduced. Because...

The development of nuclear fusion as a safe and virtually limitless power source is receiving growing attention in the context of looming energy crisis and climate change. ITER project stands as the flagship international initiative and is advancing steadily. The construction of the Tokamak Complex is nearly finished, and the assembly of core compo...

Protecting the safety of both human health and the environment necessitates the careful management of radiation. Hence, it is important to possess effective radiation shielding since unregulated exposure to radiation may lead to significant health risks and environmental damage. Utilizing appropriate materials with strong radiation shielding charac...

This survey skips the traditional safeguards of nuclear facilities to new and smart intrinsic safeguards approach, or what is technically known as safeguards by design (SbD). This concept covers the early design stage of nuclear facility and the safeguardability that considers how safety, safeguards and security (3S concept) events through design o...

The safe and reliable operation of nuclear reactors has always been one of the topmost priorities in the nuclear industry. Transient testing allows us to understand the time-dependent behavior of the neutron population in response to either a planned change in the reactor conditions or unplanned circumstances. These unforeseen conditions might occu...

This study investigates the individual and combined effects of enhancing the radiation shielding properties of waste concrete using the optimal mix design of two waste material powders of different compositions. Marble (MD) and granite (GD) waste dust were individually utilized as partial replacements for cement at a replacement ratio of 6%. Furthe...

This study investigates the impact of hybrid nanoparticles on the temperature of nuclear reactor coolant, with a focus on graphene nanoplatelet (GNP)‐based hybrid nanoparticles. Sixteen different hybrid nanofluids were analyzed, and their performance was compared with a standard water‐based coolant. The criticality values were obtained through MCNP...

In this study, we evaluated the effect of different Bi2O3 contents (45–60 mass %) on the radiation protection ability, mechanical properties, and physical properties of glass samples composed of Bi2O3-SiO2-B2O3-ZnO-Al2O3. To assess these properties, we utilized the Monte Carlo based code MCNPX 2.6.0 and the Phy-X PSD program. We calculated various...

This study is an effort to mimic and quantify the radiation absorption in a short-range radiotherapy procedure. A hollow cylindrical lead-cask was constructed and a modifiable MCNP code was developed to model the cask geometry. The model code simulates the cask with the execution of tally F75 to estimate the collisional point flux, ϕc and radiative...

Initial research indicates a possible connection between exposure to phthalates and the development of anemia. To fill the gap in epidemiological data, our study utilized data from across the United States, representative on a national scale, to evaluate the association between the concentration of phthalate metabolites in urine and both anemia and...

99m}$$ 99 m Tc, a decay product of $$^{99}$$ 99 Mo, is the most widely used radionuclide in single photon emission computed tomography (SPECT). Currently, $$^{99}$$ 99 Mo is mainly produced by nuclear reactors as isotope separation from fission products by $$^{235}$$ 235 U-enriched (HEU or LEU) uranium targets. Due to problems related to the ageing...

Effective radiation shielding is critical across various sectors, including nuclear power generation and medical applications. This study evaluates the radiation attenuation properties of seven distinct alloy samples: 316 Stainless Steel, Zircaloy-4, Monel 400, Alloy 625, Titanium Grade-5 (Ti-6Al-4V), Niobium-Titanium (NbTi) Alloy, and Haynes 230....

The CIEMAT Neutron Standards Laboratory (LPN) is the Spanish national reference laboratory in neutron metrology. Within the framework of the LPN expansion project, it has been planned to incorporate a thermal neutron field based on a graphite pile. A study has been carried out with MCNP 6.2 for a graphite pile with dimensions 180 × 150 × 150 cm 3 ,...

A passive neutron multiplicity measurement device, FH-NCM/S1, based on field-programmable gate arrays (FPGAs), is developed specifically for measuring the mass of plutonium-240 (240Pu) in mixed oxide fuel. FH-NCM/S1 adopts an integrated approach, combining the shift register analysis mode with the pulse-position timestamp mode using an FPGA. The op...

A miniature nuclear reactor is desirable for deployment as a localized nuclear power station in support of a carbon-free power supply. Coupling aspects of proliferation-resistant fuel with natural burnable absorber loading are evaluated for once-through operation cycle performance to minimize the need for refueling and fuel shuffling operations. Th...

Nuclear reaction history measurements provide a bang time and burn width of inertial confinement fusion (ICF) implosions and are essential for understanding implosion performance to constrain ICF capsule design. When fusion fuel contains Deuterium (D) and Tritium (T) gas, reaction history is informed by measuring the 16.75 MeV gamma rays generated...

The Ultra-Cold Neutron (UCN) source being commissioned at North Carolina State Universityâs PULSTAR reactor is uniquely optimized for UCN production in the former graphite-filled thermal column outside of the reactor pool. The source utilizes a remote moderation design which is particularly well suited to the PULSTAR reactor on account of its large...

Emerging studies are geared toward exploring new methods of nuclear rocket propulsion to provide more efficient space transit beyond Earth's orbit. One method is to employ a Fission Fragment Rocket Engine utilizing fissionable layers embedded in a low-density aerogel. A quantitative understanding of particle attenuation is essential for developing...

Thermoluminescence dosimeter (TLD) is widely used as a personal and medical dosimeter. Several TLD materials show the characteristics of mass energy absorption coefficient and energy response relative to ICRU (International Commission on Radiation Units and Measurements) issue material as an equivalent material for human body soft tissue. This rese...

A new neutron shielding composite was fabricated by homogenous dispersion of gadolinium oxide in the epoxy resin. It was found that the addition of Gd 2 O 3 , up to 2% has a positive effect on the tensile strength of the epoxy matrix so that its strength reached 44.5 MP with 3.1% elongation rate. This is despite the fact that according to the FTIR...

The self-sufficient supply of tritium in the deuterium-tritium nuclear fusion demonstration reactor (DEMO) is a fundamental design requirement. But, it is hindered by depletion of tritium breeding materials resulting in reduction of tritium breeding ratio (TBR) less than the initial design value especially in the solid-state tritium breeding blanke...

We propose a scalable system of compact, superconducting neutron monitors, which can be embedded in any existing cryogenic infrastructure of a fusion system. The pixel-based nature of the detectors allows them to be placed at intervals following the circumference of a cooled zone, e.g., a field coil, thus allowing for a tomographic measurement of t...

The HK-1 neutron beam line at the LVR-15 reactor in ÚJV Řež, Czech Republic, was used for in vitro cell studies carried out in the framework of the FRINGE project, aiming on the development of a novel neutron capture therapy technique using Gd containing compounds. The neutron fluence rate close the HK-1 beam exit was experimentally assessed. Neutr...

Samples of ITER materials were irradiated at the Joint European Torus (JET) to study their activation properties under neutron irradiation in a real fusion environment. The samples were irradiated at JET during the 2021 Tritium-Tritium (T-T) and Deuterium-Tritium (D-T) plasma experimental campaigns, with neutron flux levels and energy spectra compa...

Simulations using Monte Carlo GEANT4 [1] toolkit was performed to quantify parasitic neutrons production from the 3H(d,n)4He reaction in the TANDEM [2] accelerator laboratory at N.C.S.R "Demokritos". In this reaction, parasitic neutrons are produced, which contaminate the main neutron beam. For studying parasitic neutrons, the cross section biasing...

Monte Carlo simulations were carried out using the MCNP 6.1 code to predict the energy deposition at microscopic level in in vitro Neutron Capture Therapy studies. Irradiations with neutron beams of energies from 25 meV to 14.2 MeV of small spherical targets loaded with either 1000 ppm natB (200 ppm 10B) or natGd (156 ppm 157Gd) and located at the...

Two samples of Naturally Occurring Radioactive Materials (NORM) were studied using gamma-spectrometry in order to determine their radioactivity levels. The samples consisted of phosphate ore and phosphogypsum, a by-product of the phosphate fertilizer industry. Customized containers of standard geometry were filled with the above materials and then...

This paper presents a proposed revision of the International Atomic Energy Agency (IAEA) transport regulations, related to the A1 and A2 limit values used to determine the radioactive transport classification. Based on the “Q system”, a novel methodology was introduced to derive QA and QB values related to scenarios involving external exposure from...

Previously applied to REA (Rod Ejection Accident) in several PWR-like cores, the minimalistic Nodal Drift Method (NDM) has recently been generalized to sNDM (super NDM). Both developed and validated on a heat-up transient of the KRUSTY experiment made of a few homogeneous parts, sNDM basically feeds the one-group diffusion approximation with so-cal...

Linac-based electron beam therapies are used for the treatment of superficial cancer tumors. Central axis depth dose distributions for 6, 9, 12, and 15 MeV nominal electron energies delivered by Varian Clinac iX with 10 × 10 cm 2 applicator were computed by using the MCNPX (V. 2.6.0) Monte Carlo code. Percent Depth Dose (PDD) distributions computed...

The multi-decade neutron dosimeter and imaging diagnostic (MDND) is a passive diagnostic that utilizes the polyethylene (n, p) nuclear reaction to enhance the diagnostic’s sensitivity for time and energy integrated neutron measurements in the range of 2.45–14.1 MeV. The MDND utilizes a combination of radiochromic film, phosphor image plates, and so...

For developing and characterizing a novel compact D–T neutron spectrometer based on a single-crystal chemical vapor deposition diamond stack for plasma diagnostics toward future D–T fusion reactors, the initial measurement was performed using the accelerator-based D–T neutron sources OKTAVIAN at Osaka University. This neutron spectrometer was desig...

This paper presents results of neutron detection efficiency and dosimetry between a non-borated centrifugally tensioned metastable fluid detector (NB-CTMFD) configured to detect fast (>0.1 MeV) vs. He-3 based Ludlum-42-49B and the Fuji NSN3, detectors behind various levels of lead and concrete shieldin-together with MCNP code simulations to account...

This study investigates the photon interaction mechanism of various small molecule radiosensitizers, including Hydrogen Peroxide, Nimorazole, 5-Fluorouracil, NVX-108, and others, using the MCNP 6.3 Monte Carlo simulation code. The simulations focused on quantifying the linear attenuation coefficients, mean free path, and accumulation factors of the...

Molten salt reactor (MSR) shows great promise as a Generation IV nuclear reactor concept with high thermal-electric conversion efficiency, inherent safety features, and online reprocessing capability. During operation, the molten salt reactor MSR does not require a long refueling shutdown owing to online fuel reprocessing, making it suitable for wa...

The self-sufficient supply of tritium in the deuterium-tritium nuclear fusion demonstration reactor (DEMO) is a fundamental design requirement. But, it is hindered by depletion of tritium breeding materials resulting in reduction of tritium breeding ratio (TBR) less than the initial design value especially in the solid-state tritium breeding blanke...

Objective To determine the association of urinary phthalate metabolites with chronic obstructive pulmonary disease (COPD), airflow obstruction, lung function and respiratory symptoms. Methods Our study included a total of 2023 individuals aged ≥ 40 years old in the National Health and Nutrition Examination Survey (NHANES). Multivariate logistic re...

The Thermo Scientific P385 Neutron Generator is a compact neutron source, producing 14 MeV neutrons through the deuterium-tritium (DT) fusion reaction. For practical use, it is important to measure and preferably understand the dependence of the neutron production rate on the accelerator current and voltage. In this study, we evaluated neutron prod...

Simulating of transient modes and processes in nuclear reactors is carried out on the basis of point kinetics equations using effective functionals — the fraction of delayed neutrons βeff and the prompt neutrons generation time Λ. The parameter βeff also plays a key role in reactor measurements it is used in the inverted equations of point kinetics...

In this study, nature, physical characteristics and γ-ray protection features of the 50B2O3 + 1Tb4O7 + (20-X)SiO2 + 19BaF2 + 10Li2O + XAg2O, where X = 0–5 mol% glasses were investigated. Samples were prepared using the melt quenching procedure and named AgOX. The MCNP simulation code and EpiXs software (EPX) were applied to achieve the mentioned ai...

This work will target the current challenges of radiation shielding in space through the lens of modern materials science, focusing on the development and optimization of novel shielding materials. We will examine innovative solutions such as tungsten composites, tungsten-based nonporous structures, advanced aluminium alloys, and high-temperature c...

Regarding to their unique physical and mechanical features, glasses and glass–ceramics are suitable materials for shielding purposes. The present study evaluates the shielding properties of the CaF2–CaO–B2O3–P2O5–SrO–Ta2O5 glass system using Monte Carlo GEANT4 and MCNPX codes for X-ray radiations with an energy range of 20 to 100 keV. MAC values of...

As the availability and importance of high energy X-ray sources grows, accurate source characterizations provide critical information for field flatness corrections, beam hardening corrections, detector response corrections, and radiation shielding assessments. This study uses MCNP6.2 to create accurate high definition angular and energy dependent...

[Background] Molten salt reactors (MSRs) feature high temperature, low pressure, high chemical stability, and nuclear non-proliferation, which make them promising for a wide range of applications. However, owing to the fluid nature of the fuel, changes in the core structure of MSRs are bound to affect the fuel distribution and loading, consequently...

Recently, investigation of advanced shielding materials to be used as an alternative to lead apron has become important. In the current study, MgO loaded into PVC matrix as a non-lead modern shielding composite was modeled to evaluate its performance on radiation protective clothing (RPC). Parameters such as mass attenuation coefficient (MAC), mean...

For next-generation neutrinoless double beta decay experiments, extremely low backgrounds are necessary. An understanding of in-situ cosmogenic backgrounds is critical to the design effort. In-situ cosmogenic backgrounds impose a depth requirement and especially impact the choice of host laboratory. Often, simulations are used to understand backgro...

VERA benchmark cases have been introduced by ORNL and detailed guidelines have been provided including the burnup chain data for a depletion analysis. The purpose of this paper was to analyze the performance of MCNP Monte Carlo code using VERA benchmark cases. Research on the VERA benchmark cases become important because its results will be useful...