Proton boron capture therapy offers a promising enhancement to conventional proton therapy by leveraging the 11B(p,a)3a nuclear reaction for localized dose amplification. This study systematically investigates the Bragg curve characteristics of proton beams using the Geant4 Monte Carlo toolkit, with a particular focus on the dosimetric impact of ??B. The introduction of a pure ??B target induced a consistent forward shift in the Bragg peak position, attributed to increased stopping power and nuclear reactions. Furthermore, Proton boron capture therapy demonstrated enhanced local energy deposition along the central axis due to the generation of high linear energy transfer alpha particles, with minimal lateral broadening. To facilitate precise treatment planning, Bragg curve data for 800 distinct proton energies (0-80 MeV) in water were generated. Various machine learning algorithms were subsequently employed to develop predictive models for the Bragg peak position. Comparative analysis identified gaussian process regression as the optimal model, achieving an R? of 0.999997 and a root mean squared error of approximately 0.0273 mm for predicting Bragg peak positions in water. Crucially, this research pioneers a novel pathway for proton boron capture therapy treatment planning by combining high-accuracy machine learning-based prediction of the initial Bragg peak (in water) with a characterized correction for the ??B-induced forward shift, enabling more precise determination of the actual treatment depth. This work provides critical dosimetric characterization, quantifies key ??B-induced phenomena, and offers a validated predictive framework, thereby establishing a theoretical foundation and technical support for dose optimization in this emerging therapeutic modality.
Following the global trend for carbon-free energy production, Greece shut down most of its coal power plants and installed solar and wind systems for electricity production. Due to the time variations in the energy production of these systems, a complementary power source is needed, with the ability to change its output on demand. Small modular reactors combine zero-carbon emissions with the ability to vary the power production on demand. The objective of this study is to examine the energetic competitiveness of five appropriately selected small modular reactors compared to the total power production of coal power plants in Greece. The daily and monthly distribution of generated energy of the previous year (2023) is analyzed to demonstrate the potential operation of small modular reactors in Greece's electrical grid. The outcome addresses whether deploying a small modular reactor is energetically beneficial for Greece and indicates the number of modules required or how many small modular reactors, in combination with renewable sources, can meet the demand. The annual coal power plant production of Greece of 4.5 TWh can be substituted with one multi-module small modular reactor or a combination of them, appropriately located.
Vladimirs Gostilo, Andrey Vlasenko, Vasily Litvinsky
et al.
The results of the development of modern precision monitors of alpha, beta and gamma ray radiation for setting up early warning systems for radioactive contamination in the atmosphere and rapid assessment of emerging threats, are presented. Proportional counters, scintillation SrI (Eu) crystals and semiconductor Si, CdZnTe, and HPGe detectors are used for 2 the development. The designed monitors provide information both on dose rate values in real time and on the activity of specific radionuclides. The software controls the measurement mode, as well as diagnoses the condition of the monitors themselves.
Nenad Kartalovic, Saska Djekic, Sasa Djekic
et al.
Quantum mechanics consideration, supported by a concrete example, yielded standard sources of direct voltage measured by frequency (which is the most accurate measurable physical quantity) and extremely sensitive instrument for measuring magnetic induction SQUID (which is an acronym based on the term Superconducting Quantum Interference Device). The possibility of these measurements is based on the Josephson junction. In this paper, the influence of gamma radiation on the measurement uncertainty Type A, of a commercial Josephson compound, is investigated. The conclusion is that both dynamic gamma radiation and the dose of gamma radiation, under the conditions of the experiment, have a negligible effect on the measurement uncertainty of the Josephson junction. Based on the obtained result, it was concluded that in the primary metrological conditions, the measurement uncertainty type A of the Josephson junction is negligible, i. e., that the secondary cosmic radiation does not affect the standard of the DC voltage source.
Indoor radon concentrations in 33 dwellings in Arar city were measured using a CR-39 detector. This work is the first in the region and was done to assess the health risks. The exposure time was about 4 months, from May to September 2017. It was found that the indoor radon concentration changed in the range from 7.7 to 89.1 Bqm-3 with an overall average of 44.05 ? 6.21 Bqm-3 while the geometric mean is 39.51 Bqm-3 with a geometric standard deviation of 1.67. These values are within the acceptable level set by the International Committee for Radiation Protection. The annual effective dose received by the population of Arar was reported and it varied in the range 0.16 -1.82 mSv with an average value of 0.9 ? 0.16 mSv and the geometric mean is 0.81 mSv. The exposure to radon progeny was studied where the minimum, maximum, average, and geometric mean of exposure are 0.83?10-3, 9.63?10-3, 4.76 ? 0.67? 10-3 and 5.05?10-3 WLM, respectively. Finally, for the estimation of cancer risks, the excess lifetime cancer risk was investigated. Its average value was 3.7?10-3 which is relatively higher.
Aleem Tareen, Muhammad Rafique, Kimberlee Kearfot
et al.
Soil-based radon investigations are of value in correlating radon production and its transportation into buildings through the processes of convection and diffusion. Such studies can help in identifying land areas that pose special concerns. We present preliminary results of soil radon gas measurements at 60 different locations in an attempt to map out the geohazard zone of the city of Muzaffarabad. The seismic geohazard microzonation for the area includes five microzones based on different hazard parameters: a very high hazard zone, a high hazard zone, a moderate hazard zone, a low hazard zone, and a safe zone. Measurements were taken with an active radon monitoring system at the depths of 30, 40, 50, and 60 cm below the ground surface. The results obtained were explained by the lithology of the area. Average soil radon gas concentrations were correlated with the depth from the ground surface and indoor radon values for the study area. No significant correlation was found between soil radon gas and meteorological parameters, however soil radon gas increases as the depth from the surface of the ground grows. The results showed a linear relation between soil radon concentrations with depth from ground surface (R2 = 0.9577). The minimum soil radon concentration (68.5 Bq/m3) was found at a depth of 30 cm in the very high hazard zone, the maximum value (53.300 Bq/m3) at a depth of 60 cm in the seismically safe zone. Measured soil gas radon concentrations at depths of 30, 40, 50, and 60 cm were mapped for high, moderate, and low radon concentrations. Elevated soil radon gas concentrations were found in the safe zone, otherwise considered to be suitable for any type of construction.
The radiation hazards of five kinds of different solid metallic tailings collected from Shangluo, China were determined on the basis of natural radioactivity measurements using low background multichannel gamma ray spectrometry. The activity concentration of 226Ra, 232Th and 40K in the tailings ranged from 5.1 to 204.3, 3.8 to 28.5, and 289.6 to 762.3 Bq/kg, respectively. The radium equivalent activities and the external hazard indexes of all studied metallic tailings were below the internationally accepted value of 370 Bq/kg and unity, respectively. The internal hazard index of vanadium tailings exceeded unity, while the internal hazard indexes of other analyzed metallic tailings were less than unity. The indoor air absorbed dose rate values for all studied metallic tailings except lead-zinc tailings and gold tailings were higher than the world population-weighted average of 84 nGy/h and the annual effective dose values of all metallic tailings except for vanadium tailings were lower than 1 mSv. The study showed that vanadium tailings present a radiation hazard and their usage as building materials should be restricted.
The Fukushima Daiichi nuclear power plant accident shows that natural disasters such as earthquakes and the subsequent tsunamis can cause station blackout for several days. The electric energy required for essential systems during a station blackout is provided from emergency backup batteries installed at the nuclear power plant. In South Korea, in the event of an extended station blackout, the life of these emergency backup batteries has recently been extended from 8 hours to 24 hours at Shin-Kori 5, 6, and APR1400 for design certification. For a battery life of 24 hours, available safety means system, equipment and procedures are studied and analyzed in their ability to cope with an extended station blackout. A sensitivity study of reactor coolant pump seal leakage is performed to verify how different seal leakages could affect the system. For simulating extended station blackout scenarios, the best estimate MARS-KS computer code was used. In this paper, an APR1400 RELAP5 input deck was developed for station blackout scenario to analyze operation strategy by manually depressurizing the reactor coolant system through the steam generator's secondary side. Additionally, a sensitivity study on reactor coolant pump seal leakage was carried out.
A study on neutron kerma factors and photon air-kerma for human organs is presented for neutron energy range 2.53?10-8 MeV to 29 MeV and photon energy range 1 keV to 20 MeV. The human organs water equivalence for photon and neutron, is also presented. The ratio of the mass-energy absorption coefficients of human organs to water was found constant and unity above 100 keV, whereas there was a large difference for energies below 100 keV. The neutron kerma factors of human organs and water are found of same order of magnitude whereas differs for air. The neutron kerma factors of human organs and tissue substitutes were found to be equal to water for neutron energies between 63 eV and 200 keV. The skeleton-cortical bone was found to be away from water equivalence for low-energy photons and high-energy neutrons.
Matti Kauppinen, Esko Alasaarela, Antero Koivula
et al.
The dosimetry is used to verify the dose magnitude with artificial samples (phantoms) before giving the planned radiation therapy to the patient. Typically, dose distribution is measured only in a single point or on a two-dimensional matrix plane. New techniques of radiation therapy ensure more detailed planning of radiation dose distribution which will lead to the need of measuring the radiation dose distribution three-dimensionally. The gel dosimetry is used to indicate and determine the ionizing radiation three-dimensionally. The radiation causes changes in chemical properties of the gel. The radiation dose distribution is defined by measuring the chemical changes. A conventional method is the magnetic resonance imaging and a new possibility is optical computed tomography (optical-CT). The optical-CT is much cheaper and more practical than magnetic resonance imaging. In this project, an optical-CT based method device was built by aiming at low material costs and a simple realization. The constructed device applies the charge coupled device camera and fluorescent lamp technologies. The test results show that the opacity level of the radiated gel can be measured accurately enough. The imaging accuracy is restricted by the optical distortion, e. g. vignetting, of the lenses, the distortion of a fluorescent lamp as the light source and a noisy measuring environment.
In the present study, the bark of oak trees (Quercus petraea Liebl.) was collected from Belgrade Forest northwest of Istanbul for determination of 137Cs, 40K, 232Th, and 238U activity. A gamma spectrometer equipped with high-purity germanium detector was used for radioactivity measurement. Bark samples were collected from the northern and southern sides of trees at a height of 1.5 m above the ground in order to see the effects of rainfall and wind; and they were also collected from the northern side at a height of 0.5 m above the ground to assess the effect of soil splash. The activity concentrations of 137Cs, 40K, 232Th, and 238U in the bark samples were found to vary in the range of 1.40-27.50, 45.0-221.2, 0.92-9.64, and 4.04-36.10 Bq/kg, respectively. The elevated activity of 238U in bark samples could be attributed to a large amount of coal combustion in the region until the 1990s. According to one-way ANOVA, a significant difference was not found in bark samples collected at a height of 0.5 m and 1.5 m above the ground in terms of radionuclide activity. There was also no significant variation regarding radionuclide accumulation between northern and southern sides.
The essential prerequisite of radiation dosimetry is to provide quality assurance and documentation that the irradiation procedure has been carried out according to the specification requirement of correct calibration of the chosen dosimetry system. At the Radiation Plant of the Vinca Institute of Nuclear Sciences we compared two recommended protocols of irradiation procedures in the calibration of dosimetry systems in radiation processing: (1) by irradiation of routine dosimeters (ethanol-chlorobenzene - ECB) at the calibration laboratory and (2), by in-plant calibration with alanine transfer - dosimeters. The critical point for in-plant calibration is irradiation geometry, so we carefully positioned the phantom carrying both dosimeters in order to minimize dose gradients across the sample. The analysis of results obtained showed that the difference among determined absorbed doses for the construction of calibration curves between these two methods, (alanine vs. ECB), is less than 1%. The difference in combined standard uncertainty for each calibration procedure is 0.1%. These results demonstrate that our in-plant calibration is as good as calibration by irradiation at the calibration laboratory and validates our placement of the irradiation phantom during irradiation.
On-line software for adaptively canceling 50 Hz line frequency noise has been designed and tested at Pakistan Research Reactor 1. Line frequency noise causes much problem in weak signals acquisition. Sometimes this noise is so dominant that original signal is totally corrupted. Although notch filter can be used for eliminating this noise, but if signal of interest is in close vicinity of 50 Hz, then original signal is also attenuated and hence overall performance is degraded. Adaptive noise removal is a technique which could be employed for removing line frequency without degrading the desired signal. In this paper line frequency noise has been eliminated on-line from a nuclear power measuring channel. The adaptive LMS algorithm has been used to cancel 50 Hz noise. The algorithm has been implemented in labVIEW with NI 6024 data acquisition card. The quality of the acquired signal has been improved much as can be seen in experimental results.
Dragana Jordanov, Bojana Grabez, Krunoslav Subotic
et al.
We propose a new method for determination of temperature in spallation events. It is shown that temperature can be determined by applying the friction model of energy dissipation in participant-spectator model of a spallation process. First order estimate of temperature dependence of the participant zone on reaction Q-value is obtained from the Fermi gas model considerations. The heat diffusion process is also discussed.
In this work, we are interested to simulate the thermal-hydraulic behavior of three-pass type fire-tube boiler. The plant is designed to produce 4.5 tons per hour of saturated steam at 8 bar destined principally for heating applications. A calculation program is developed in order to simulate the boiler operation under several steady-state operating conditions. This program is based upon heat transfer laws between hot gases and the fire-tube internal walls. In the boiler combustion chamber, the heat transfer has been simulated using the well-stirred furnace model. In the convection section, heat balance has been carried out to estimate the heat exchanges between the hot gases and the tube banks. The obtained results are compared to the steady-state operating data of the considered plant. A comparative analysis shows that the calculation results are in good agreement with the boiler operating data. Furthermore, a sensitivity study has been carried out to assess the effects of input parameters, namely the fuel flow rate, air excess, ambient temperature, and operating pressure, upon the boiler thermal performances.
In earlier Rastovic's papers [1] and [2], the effort was given to analyze the stochastic control of tokamaks. In this paper, the deterministic control of tokamak turbulence is investigated via fractional variational calculus, particle in cell simulations, and fuzzy logic methods. Fractional integrals can be considered as approximations of integrals on fractals. The turbulent media could be of the fractal structure and the corresponding equations should be changed to include the fractal features of the media.
Srpko Markovic, Rodoljub Simovic, Vladan Ljubenov
et al.
This paper shows the results of Monte Carlo simulations of the photon reflection from homogenous plates of the shield materials made of water, aluminum, and iron. Perpendicular incidence of a monoenergetic photon beam of the initial energy of 20 keV up to 100 keV is considered. The numerical experiments were performed using the verified Monte Carlo programs MCNP-4C, FOTELP-2K3, and PENELOPE-2005. As the result, the values of difference number albedo distributed in ten even intervals according to the energy and nine even intervals according to the polar angle of reflected photons were obtained. Out of these data, the spectral albedo coefficients for all three materials and three initial photon energies of 40 keV, 60 keV, and 100 keV were calculated, graphically presented, and analyzed. The values of the spectral albedo determined on the basis of MCNP-4C code were compared to the results of the early simulations of the photon reflection performed in Russia and in the USA. Also, with the help of MCNP-4C program, the yield of fluorescent photons to the spectrum of the reflected radiation was registered, which can be seen in the graphs in the form of the peak at the energy of 7.112 keV only at the shielding plates made of iron.
Djordje Saponjic, Aleksandar Zigic, Vojislav Arandjelovic
The distributed measurement system - HYPERION NET, based on the concept of FieldBus technology, has been developed, implemented, and tested as a pilot project, the first WEB enabled on-line networked ionizing radiation monitoring and measurement system. The Net has layered the structure, tree topology, and is based on the Internet infrastructure and TCP/IP communication protocol. The Net' s core element is an intelligent GM transmitter, based on GM tube, used for measuring the absorbed dose in air in the range of 0.087 to 720 ?Gy/h. The transmitter makes use of an advanced count rate measurement algorithm capable of suppressing the statistical fluctuations of the measured quantity, which significantly improves its measurement performance making it suitable for environmental radiation measurements.