Accelerator Driven System Reactor Research Articles

Online identification of trips caused by the external proton source in an ADS reactor

New fields in the domain of signal analysis began with the improvement of the techniques that gave rise to Wavelet Transforms in the late 1980s and early 1990s. Another important element that allowed the development and use of new methods in signal analysis was the increase in processing power of modern computers, which also contributed to the development and application of Wavelet Transforms. This work uses the Haar Wavelet in the analysis of the neutron flux of an Accelerator Driven System (ADS) reactor to provide a method for the online identification of trips in the external neutron source as produced by transients. In order to obtain the necessary data, an ADS reactor was simulated, based on the MYRRHA reactor, with the use of the Serpent Physics reactor code.

K effective factor in the ADSR using liquid lead target and (Th233U)O2, (Th235UO)2, (Th238U)O2 fuel mixture

The study of using liquid lead target for the accelerator driven subcritical reactor (ADSR) has been proposed by Nguyen Mong Giao, Vu Thi Diem Hang, Tran Minh Tien (International Journal of Modern Physics and Application. Vol. 2, No. 3, 2015). The calculations about neutron distribution, neutron fluxwith thorium fuel and thorium mixturehas been showed by Tran Minh Tien (Distribution of Neutrons from The Reaction (p, n) on the Liquid Lead Target in The Accelerator Driven System Reactor, J. Phys.: Conf. Ser. 1172 012066, 2019; Distributions of neutron flux from (p, n) reaction on the liquid lead target for accelerator driven subcritical reactor (ADSR), J. Phys.: Conf. Ser. 1324 012061, 2019). In this paper, the k effective factor is calculated with(Th233U)O2, (Th235U)O2and(Th238U)O2fuel mixture.

226Ra irradiation to produce 225Ac and 213Bi in an accelerator-driven system reactor

This study aims to produce 229Th using an innovative nuclear reactor concept, i.e., accelerator-driven system (ADS) reactor. Herein, we investigated the feasibility of producing 229Th from neutron transmutation of 226Ra to expand the availability of 225Ac and 213Bi in a simple model of ADS reactor. ADS reactor comprises two zones, i.e., an inner zone with a fast neutron spectrum and outer zone with thermal neutron spectrum, which is a subcritical core coupled with an external neutron source. Transmutation behavior, activity, and mass ratio of the obtained isotopes were investigated using the Monte-Carlo tool. In addition with offering the capability, flexibility, and safety of radioactive waste transmutation, the proposed ADS model provides high 229Th yield and requires less time than a critical reactor with the same neutron flux and irradiated quantity of 226Ra.

Numerical Investigation of Th-229 Production in an Accelerator Driven System Reactor

The expected increase in radionuclide demand for treatment of various tumor diseases has led to the investigation of alternative production routes to provide sufficient amount of medical isotopes [1]. In Targeted Alpha Therapy (TAT), there is a present and future need for the Ac-225 and Bi-213, as the most promising alpha emitting isotopes, one of the limited ways to provide these radioisotopes is by production of Th-229 in reactor route [2][3]. The present study conducted to investigate the production of Th-229 to expand the availability of Ac-225 and Bi-213 in innovative nuclear reactor concept like Accelerator Driven System reactor (ADS)[4], which is a subcritical reactor and currently in development that predict to play an important role in the transmutation process of heavy elements and isotopes production. The possibility of producing Th-229 from neutron transmutation of Ra-226 are numerically investigated for simple model of ADS reactor consist of two zones, inner region with fast neutron spectra and outer region with thermal neutron spectra, and the subcritical core coupled with external neutron source. The calculations of transmutation behavior and mass ratio for the produced isotopes are conducted by using Monte Carlo N-particle Transport (MCNPX) code. This research was supported by International Center for Theoretical Physics and The Institute of International Education Scholar Rescue Fund. My deep thanks to colleagues from Institute for Safety Problems of Nuclear Power Plants, Ukraine who provided expertise that assisted the research. [1]E. R. Birnbaum, L. J. Bitteker, A. Couture, and M. E. Fassbender, “Ac and Ra-223 Production via 800 MeV Proton Irradiation of Natural Thorium Targets,” vol. 836.[2]J. R. Griswold et al., “Large scale accelerator production of Ac-225: Effective cross sections for 78–192 MeV protons incident on Th-232 targets,” Appl. Radiat. Isot., 2016.[3]S. Hogle et al., “Reactor production of Thorium-229,” Appl. Radiat. Isot., vol. 114, pp. 19–27, 2016.[4]H. Aït Abderrahim, P. Baeten, D. De Bruyn, and R. Fernandez, “MYRRHA - A multi-purpose fast spectrum research reactor,” in Energy Conversion and Management, 2012, vol. 63, pp. 4–10.

Distribution of Neutrons from The Reaction (p, n) on the Liquid Lead Target in The Accelerator Driven System Reactor

This paper presents results of calculating energy distribution, angular distribution, neutron yield, the double-differential cross-section of the neutron as a proton beam, which produced from the accelerator, spallation on the liquid lead, thus providing the basis for the distribution of the target, calculating fuel … for the accelerator-driven reactor system reactor. These results have shown that the produced neutron energy spectrum extends from thermal neutrons to fast neutrons, which have concentrated in 1MeV to 3MeV. These neutrons are produced at angles of 0° to 10° and turn decreased to the larger angles. This shows that neutrons tend to be produced forward in the direction of the incoming protons.

Numerical Investigation of Th-229 Production in an Accelerator Driven System Reactor

The expected increase in radionuclide demand for treatment of various tumor diseases has led to the investigation of alternative production routes to provide sufficient amount of medical isotopes [1]. In Targeted Alpha Therapy (TAT), there is a present and future need for the Ac-225 and Bi-213, as the most promising alpha emitting isotopes, one of the limited ways to provide these radioisotopes is by production of Th-229 in reactor route [2][3]. The present study conducted to investigate the production of Th-229 to expand the availability of Ac-225 and Bi-213 in innovative nuclear reactor concept like Accelerator Driven System reactor (ADS)[4], which is a subcritical reactor and currently in development that predict to play an important role in the transmutation process of heavy elements and isotopes production. The possibility of producing Th-229 from neutron transmutation of Ra-226 are numerically investigated for simple model of ADS reactor consist of two zones, inner region with fast neutron spectra and outer region with thermal neutron spectra, and the subcritical core coupled with external neutron source. The calculations of transmutation behavior and mass ratio for the produced isotopes are conducted by using Monte Carlo N-particle Transport (MCNPX) code. This research was supported by International Center for Theoretical Physics and The Institute of International Education Scholar Rescue Fund. My deep thanks to colleagues from Institute for Safety Problems of Nuclear Power Plants, Ukraine who provided expertise that assisted the research. [1]E. R. Birnbaum, L. J. Bitteker, A. Couture, and M. E. Fassbender, “Ac and Ra-223 Production via 800 MeV Proton Irradiation of Natural Thorium Targets,” vol. 836.[2]J. R. Griswold et al., “Large scale accelerator production of Ac-225: Effective cross sections for 78–192 MeV protons incident on Th-232 targets,” Appl. Radiat. Isot., 2016.[3]S. Hogle et al., “Reactor production of Thorium-229,” Appl. Radiat. Isot., vol. 114, pp. 19–27, 2016.[4]H. Aït Abderrahim, P. Baeten, D. De Bruyn, and R. Fernandez, “MYRRHA - A multi-purpose fast spectrum research reactor,” in Energy Conversion and Management, 2012, vol. 63, pp. 4–10.

Transmutation performance of uniform and nonuniform distributions of plutonium and minor actinides in TRIGA Mark II ADS reactor

For long times there has been a sustained international interest in partitioning and transmutation of spent fuel produced by fission reactors, in particular both plutonium (Pu) and minor actinides (MA), which are associated with nuclear proliferation risks and radioactivity hazards. Transmutation requires the Pu and MA to be irradiated in a very intense neutron flux that can only be attained in a high power fission system such as a thermal reactor, a fast reactor or an accelerator driven system (ADS). The present work investigated two proposed models of core design of different Pu and MA distribution (uniform and nonuniform) applied to TRIGA Mark II ADS reactor to maximize fuel utilization, covering energy extraction and Pu/MA mass reduction. Transmutation performance was studied through burnup and mass ratio time evolution calculations of fuel and minor actinides various components including U, Pu, Am and Cm isotopes, up to two years operation cycle using MCNPX Transport code.

Transient safety analysis for simplified accelerator driven system with gas-lift pump

Owing to remarkable advantage for transmutation of the long-lived nuclear waste, Accelerator Driven System (ADS) is one of the most promising systems in nuclear power field. In this study, the transient analysis of a simplified lead bismuth alloy cooling accelerator driven system with gas-lift pump has been numerically simulated. By using point reactor neutron kinetics equation and related thermal-hydraulic models, TASAR (Transient Analysis of Simplified ADS Reactor) code is developed. The five kinds of transient cases are simulated: Starting gas-lift pump (SG), Unprotected loss of flow (ULOF), Beam interruption (BI), Unprotected transient over current (UTOC), Unprotected transient overpower (UTOP). Meanwhile, the calculation results of TASAR code are validated by the experimental data of NACIE (Natural Circulation Experiment) facility. The analysis is as following: In SG and ULOF conditions, the introduction of gas-lift pump has a remarkable influence of loop natural circulation capability. In BT and UTOC conditions, the short-time beam cutting off and a 100% increase of the external neutron source would not lead to the immediate fuel melting. In UTOP condition, a reactivity jump of 2$ would not lead to the damage of fuel and the cladding. The above numerical results show that, the accelerator and gas-lift pump influence the loop mass flow rate and core temperatures of research system in this paper greatly, and the simplified accelerator driven system with gas-lift pump has a very good safety performance.

Optimization of breeding properties of the spallation neutron source target for ADS

One of the main components of an ADS (accelerator-driven reactor systems) is the spallation target, generating neutrons for power plant. Neutrons are generated due in spallation reactions induced on heavy nuclei by accelerator beam of high-energy protons with subsequent multiplication of neutrons in the cascade process of interactions of secondary intermediate-energy particles with target nuclei, subcritical core and blanket.On average, from 20 (for Hg and Pb targets) to 50 (for U target) neutrons are produced per 1-GeV proton in spallation reactions in the target containing nuclei of heavy elements (for example, Hg, Ta, W, U,).Heavy elements such as lead, bismuth, mercury, tantalum, and tungsten are considered as suitable materials for the targets. Lead-bismuth eutectic targets are successfully developed.It is demonstrated in the present paper that there exist optimal size of the target material allowing obtaining for the given incident particle energy maximum number of “spallation” neutrons. Results of calculations of energy spectrum of neutrons generated in the proton interactions with heavy targets for the energy range of incident protons from 0.8 to 1.4GeV.Implemented analysis of variation of neutron generation rate for cylindrical target with 10cm diameter and length from 1 to 120cm at impinging proton energies from 0.8 to 1.4GeV allowed calculating optimal target dimensions consisting of heavy nuclei for the nuclear power installations under design.Optimization of dimensions of neutron generating targets consisting of natural natBi, natHg, natPb и natW isotopes was implemented.

Higher order mode beams mitigate halos in high intensity proton linacs

High intensity proton linacs (HIPLs) for applications such as Accelerator Driven Reactor Systems (ADRS) have serious beam dynamics issues related to beam halo formation. This can lead to particle loss and radioactivation of the surroundings which consequently limit the beam current. Beam halos are largely driven by the nonlinear space-charge force of the beam, which depends strongly on the beam distribution and also on the initial beam mismatch. We propose here the use of a higher order mode beam (HOMB), that has a weaker nonlinear force, to mitigate beam halos. We first show how the nonlinear space-charge force can itself be exploited in the presence of nonlinear solenoid fields, to produce a HOMB in the low energy beam transport (LEBT) line. We then study the transport of such a beam through a radio frequency quadrupole (RFQ), and show that the HOMB has a significant advantage in terms of emittance blow-up, halo formation and beam loss, over a Gaussian beam, even with a finite initial mismatch. For example, for the transport of a 30 mA beam through the RFQ, with an initial beam mismatch of 45%, the Gaussian beam sees an emittance blow-up of 125%, while the HOMB sees a blow-up of only 35% (relative to the initial emittance of $0.2\ensuremath{\pi}\text{ }\text{ }\mathrm{mm}\text{\ensuremath{-}}\mathrm{mrad}$). Similarly, the beam halo parameter and beam loss are 0.95 and 25% respectively for a Gaussian beam, but only 0.35 and 15% for a HOMB. The beam dynamics of the HOMB agrees quite well with the particle-core model, because of the more linear space-charge force, while for the Gaussian beam there are additional particle loss mechanisms arising from nonlinear resonances. Therefore, the HOMB suppresses emittance blow-up and halo formation, and can make high current ADRS systems more viable.

Effects of Pu and MA uniform and nonuniform distributions on subcritical multiplication of TRIGA Mark II ADS reactor

Plutonium (Pu) and minor actinides (MAs) are responsible for the majority of radiotoxicity, heat generation, and proliferation risk of nuclear spent fuel. Accelerator driven system (ADS) reactors can employ Pu and MA for transmutation and power generation within improved safety scheme. Pu and MA can be loaded in ADS reactor core in a variety of distributions. In this study, the effects of uniform and nonuniform distributions of Pu and MA samples loaded within enriched uranium fuel elements inside UT-TRIGA Mark II ADS reactor on neutron flux, neutron spectrum, fission rate, and subcritical multiplication parameters were numerically investigated using Monte Carlo MCNPX transport code. The type of distribution producing higher subcritical multiplication and source efficiency will contribute in minimizing the accelerator current requirements for ADS operation.

Seismic Isolation of Reactor Assembly for a Fixed Base Accelerator Driven System Reactor Building

In the SILER (Seismic-Initiated events risk mitigation in LEad-cooled Reactors) Project, it is interesting to apply seismic isolation technology for the reactor assembly of the fixed base reactor building for ADS (Acceleration Driven System) heavy liquid reactor MYRRHA (Multipurpose Hybrid Research Reactor for High-Tech Application) which contains the most critical safety related components, such as reactor vessel, safe shutdown and control rod mechanisms, primary heat exchangers, primary pumps, spallation target assembly and fuel assemblies, etc. The purpose of this paper is to investigate the possibility of an application of a partial seismic isolation to the safety critical components only, here, the reactor assembly. This paper presents the preliminary analysis results of the isolated reactor assembly and compares these with those of seismic isolated ADS reactor building. The analysis results show the reduction of the seismic acceleration response but the increase of the relative displacement for the reactor assembly. Some safety issues, especially, coolant's incapable covering the reactor core make difficult to apply for the partial seismic isolation of the ADS reactor assembly due to large relative displacement occurring the partial isolation system. Further study on the partial seismic isolation application of the critical safety components are also discussed.

Neutrino physics with accelerator driven subcritical reactors

Accelerator driven system (ADS) subcritical nuclear reactors are under development around the world. They will be intense sources of free, 30-50 MeV antimuon decay at rest antimuon neutrinos. These ADS reactor neutrinos can provide a robust test of the LSND anomaly and a precise measurement of the leptonic CP-violating phase delta, including sign(cos(delta)). The first phase of many ADS programs includes the construction of a low energy, high intensity proton or deuteron accelerator, which can yield competitive bounds on sterile neutrinos.

Verification of Neutronics and Thermal-hydraulics Coupled Simulation Program NTC by the PDS-XADS transient simulation

In this paper, the steady state and three typical transient accidents of LBE-cooled sub-critical experimental accelerator driven system reactor were simulated by the Neutronics and Thermal-hydraulics Coupled Simulation Program (NTC) developed by FDS team. The three transient accidents were beam trip (BT), unprotected beam overpower (UBOP) and unprotected transient overpower (UTOP). The NTC-based simulation results of PDS-XADS were compared with those based on SIMMER-III, and the simulation and comparison results showed that the trends of all the neutronics and thermal-hydraulics parameters of NTC-based simulations in this study were similar and close to those of SIMMER-III-based simulation results, which verified the simulation capacity and correctness of NTC code in a manner.

Structural Investigation of (U0.7Pu0.3)O2-x Mixed Oxides.

Uranium-plutonium mixed oxide containing 30% of plutonium is a candidate fuel for several fast neutron and accelerator driven reactor systems. In this work, a detailed structural investigation on sol-gel synthesized stoichiometric U0.7Pu0.3O2.00 and substoichiometric U0.7Pu0.3O2-x, using X-ray diffraction (XRD), oxygen 17 magic angle spinning nuclear magnetic resonance ((17)O MAS NMR) and X-ray absorption spectroscopy is described. As observed by XRD, the stoichiometric U0.7Pu0.3O2.00 is monophasic with a lattice parameter in good agreement with Vegard's law, while the substoichiometric U0.7Pu0.3O2-x material is biphasic. Solid solution ideality in terms of a random distribution of metal atoms is proven for U0.7Pu0.3O2.00 with (17)O MAS NMR. X-ray absorption near-edge structure (XANES) spectroscopy shows the presence of plutonium(III) in U0.7Pu0.3O2-x. Extended X-ray absorption fine-structure (EXAFS) spectroscopy indicates a similar local structure around both cations, and comparison with XRD indicates a close similarity between uranium and plutonium local structures and the long-range ordering.

Calculation of reactivity in subcritical reactors using the method of partial derivatives

The analysis of source-driven subcritical reactors is of great interest as it allows savings in the mineral resources used in their cores, due to the possible transmutation of nuclear fuel burned in critical reactors. In ADS (Accelerator Driven System) reactors the neutrons produced from spallation reactions generate an source, external to the core, that supports its operation. Although there are different formalisms to describe the kinetic behaviour of these reactors, its functioning remains an open question, as there is no ADS reactor in operation. Thus, with the aim of predicting reactivity behaviour in this type of reactor, the inverse point kinetics equation was obtained, using a specific formalism for subcritical reactors. The results obtained were compared to Monte Carlo simulations for the purposes of validation and were shown to be coherent, displaying deviations under 100pcm.

The physics of accelerator driven sub-critical reactors

In recent years, there has been an increasing worldwide interest in accelerator driven systems (ADS) due to their perceived superior safety characteristics and their potential for burning actinides and long-lived fission products. Indian interest in ADS has an additional dimension, which is related to our planned large-scale thorium utilization for future nuclear energy generation. The physics of ADS is quite different from that of critical reactors. As such, physics studies on ADS reactors are necessary for gaining an understanding of these systems. Development of theoretical tools and experimental facilities for studying the physics of ADS reactors constitute important aspect of the ADS development program at BARC. This includes computer codes for burnup studies based on transport theory and Monte Carlo methods, codes for studying the kinetics of ADS and sub-critical facilities driven by 14 MeV neutron generators for ADS experiments and development of sub-criticality measurement methods. The paper discusses the physics issues specific to ADS reactors and presents the status of the reactor physics program and some of the ADS concepts under study.

Experience with irradiation of LiSoR test section no. 3

LiSoR (liquid metal–solid metal reaction) loop is a unique facility which was designed to investigate simultaneously the influence of flowing lead bismuth eutectic (LBE), static stress and irradiation by protons onto steel that might be used as structural material in a future ADS (accelerator driven system) reactor. LiSoR is worldwide the first LBE loop that is under operation while it is irradiated at the same time. Up to now five LiSoR test sections have been irradiated. In this paper the experience on LiSoR no. 3 is presented including irradiation experiment and dissembling of the test section and EDM wire cutting of the samples. Additionally the results obtained by SEM and EDX analyses on LiSoR specimen and on beam window are shown whereby the most interesting outcome is the finding of an oxide layer, which was clearly identified by X-ray mapping. This layer is located directly in the irradiated area having a total thickness less than 1 μm. Additionally solidified LBE was detected on some areas of the samples but no wetting of the steel or penetration of LBE into the steel matrix was observed. No enrichment or dissolution of steel elements such as Fe and Cr could be detected on the surface near area. The steel surface is still smooth without any indications of corrosion attack.

99/03701 Loss-of-cooling consequences in critical and in accelerator driven reactor systems: Van Dam, H. Annals Nucl. Energy, 1999, 26, (16), 1489–1495

99/03701 Loss-of-cooling consequences in critical and in accelerator driven reactor systems: Van Dam, H. Annals Nucl. Energy, 1999, 26, (16), 1489–1495

Study of accelerator-driven reactor systems / Untersuchung von Beschleuniger-betriebenen Reaktorsystemen

Basic features of accelerator driven reactor systems were investigated. The sensitivity of the calculation of reactor parameters to the selection of calculation models, approximations and uncertainty of input parameters was examined. Effective criticality factor, source criticality factor, particle spectra, energy deposition, radiation damage rate for structural materials, Doppler coefficient have been calculated for different core design.