Papers by Carlo Petrovich
Interfaces with Proton Beam of the Pb-Bi Cooled XADS
The main contribution to the activation of the above reactor structures arises from the neutron s... more The main contribution to the activation of the above reactor structures arises from the neutron streaming along the core axis, through the proton beam pipe vacuum. While the access of the personnel is not necessary when the reactor is running, it is required for refuelling operations a few days after the reactor shutdown, and the target unit must be extracted for this purpose. A dose rate of 150-1000µSv/h may represent the very upper limit for occupational exposure of the personnel. In the original beam pipe geometry, regardless which option is retained for the target (i.e. window or windowless), the initial dose estimates are of the order of 10-2Sv/h and thus too high, even some weeks after shutdown. The choice of low activation materials does not reduce enough the dose rate. In order to reduce the reactor roof activation, we have focused on the windowless option for the target unit, which is the most viable solution for: i) Reducing the beam pipe cross-sectional area. According to...
The main contribution to the activation of the above reactor structures arises from the neutron s... more The main contribution to the activation of the above reactor structures arises from the neutron streaming along the core axis, through the proton beam pipe vacuum. While the access of the personnel is not necessary when the reactor is running, it is required for refuelling operations a few days after the reactor shutdown, and the target unit must be extracted for this purpose. A dose rate of 150-1000µSv/h may represent the very upper limit for occupational exposure of the personnel. In the original beam pipe geometry, regardless which option is retained for the target (i.e. window or windowless), the initial dose estimates are of the order of 10-2Sv/h and thus too high, even some weeks after shutdown. The choice of low activation materials does not reduce enough the dose rate. In order to reduce the reactor roof activation, we have focused on the windowless option for the target unit, which is the most viable solution for: i) Reducing the beam pipe cross-sectional area. According to...
Nuclear Engineering and Design, 2014
• The design for the lead fast reactor is conceived in a comprehensive approach.
COMPARISON BETWEEN THE MONTE CARLO CODES MCNPX AND FLUKA WITHIN THE FRAMEWORK OF CALCULATIONS FOR THE TRADE EXPERIMENT
The TRADE experiment, to be performed at the TRIGA nuclear reactor of the ENEA Casaccia Centre (R... more The TRADE experiment, to be performed at the TRIGA nuclear reactor of the ENEA Casaccia Centre (Rome, Italy) consists in the coupling of an external proton accelerator to a spallation target to be installed in the central channel of the reactor kept in a sub-critical configuration. TRADE is meant to represent a major demonstration step of the Accelerator-Driven-Systems concept. Monte Carlo calculations are needed for the radiation transport analysis of various aspects of the experiment. The Monte Carlo general purpose codes MCNPX and FLUKA have been applied, among other issues, to the analysis of the shielding configuration of the beam transport line and to the assessment of the radioactivity induced by the impact of the 140 MeV proton beam with the target. In the shielding analysis the dose rates due to the proton beam leakage along the transport line have been calculated for points beyond the barytic concrete shields. Various leakage angles with respect to the beam axis have been ...
A specific aim of the EUROTRANS Integrated Project, partially financed in the European 6th Framew... more A specific aim of the EUROTRANS Integrated Project, partially financed in the European 6th Framework Program (by EU), is to demonstrate the conceptual feasibility of high rate Minor Actinides transmutation in an Accelerator Driven System. This concept reactor, called European Facility on Industrial scale Transmuter (EFIT), is fuelled by U-free (Pu, MA)O2-x + MgO innovative Cer-Cer fuel type with high MA content and is cooled by lead. The design of the sub-critical core is based on the so called "42-0" transmutation rate approach, characterized by zero Pu net balance and maximum MA transmutation rate of 42 kg/TWhth together with reduced BU reactivity loss (~200 pcm/year). An essential requirement for the EFIT reactor is that it remains sub-critical in any plant condition. To avoid unwanted returns to criticality, the sub-criticality level and the reactivity coefficients should be known with high accuracy. In this paper, the sensitivity of the Keff and of the reactivity coef...
This paper provides a comparison of the performance of an electron accelerator-driven experiment,... more This paper provides a comparison of the performance of an electron accelerator-driven experiment, under discussion within the Reactor Accelerator Coupling Experiments (RACE) Project, being conducted within the U.S. Department of Energy's Advanced Fuel Cycle Initiative (AFCI), and of the proton-driven experiment TRADE (TRiga Accelerator Driven Experiment) originally planned at ENEA-Casaccia in Italy. Both experiments foresee the coupling to sub-critical TRIGA core configurations, and are aimed to investigate the relevant kinetic and dynamic accelerator-driven systems (ADS) core behavior characteristics in the presence of thermal reactivity feedback effects. TRADE was based on the coupling of an upgraded proton cyclotron, producing neutrons via spallation reactions on a tantalum (Ta) target, with the core driven at a maximum power around 200 kW. RACE is based on the coupling of an Electron Linac accelerator, producing neutrons via photoneutron reactions on a tungsten-copper (W-Cu)...
The main contribution to the activation of the above reactor structures arises from the neutron s... more The main contribution to the activation of the above reactor structures arises from the neutron streaming along the core axis, through the proton beam pipe vacuum. While the access of the personnel is not necessary when the reactor is running, it is required for refuelling operations a few days after the reactor shutdown, and the target unit must be extracted for this purpose. A dose rate of 150-1000µSv/h may represent the very upper limit for occupational exposure of the personnel. In the original beam pipe geometry, regardless which option is retained for the target (i.e. window or windowless), the initial dose estimates are of the order of 10-2Sv/h and thus too high, even some weeks after shutdown. The choice of low activation materials does not reduce enough the dose rate. In order to reduce the reactor roof activation, we have focused on the windowless option for the target unit, which is the most viable solution for: i) Reducing the beam pipe cross-sectional area. According to...
The "Lead-cooled European Advanced DEmonstration Reactor" (LEADER) project, approved by the Europ... more The "Lead-cooled European Advanced DEmonstration Reactor" (LEADER) project, approved by the European Union within the 7th EURATOM Framework Programme, was addressed with the twofold goal of further developing the conceptual design of the reference Generation-IV LFR for industrial use, and of conceiving the Advanced Lead-cooled Fast Reactor European Demonstrator. ALFRED is a 300 MWth pool system aimed at proving the viability of the design concept adopted for the European LFR systems, while demonstrating the effectiveness of the safety features that are implemented in a simple, passive, robust and economic way.
The impact of the different sets of nuclear data on the criticality level and reactivity coeffici... more The impact of the different sets of nuclear data on the criticality level and reactivity coefficients of critical and sub-critical LMFR cores is discussed. A sensitivity analysis, by direct substitution of the nuclear data of different origin (JEFF, ENDF/B, JENDL families), was performed. Large discrepancies on the neutron parameters, among the different nuclear data sets, are observed. Such an investigation, in stochastic approach by single isotope or group of isotopes substitution, highlights the isotopes and/or the reaction events that are mainly responsible for the most significant discrepancies. Both radiotoxicity and residual risk reduction require high accuracy of the nuclear data, mainly for the Minor Actinides. Finally, the impact of these uncertainties could be an important issue also for the economic aspects of dedicated cores.
Minor Actinides Transmutation in the EFIT Reactor: A Design Challenge
In the EUROTRANS Integrated Project, funded by the European Union (EU) within the 6th FP (Framewo... more In the EUROTRANS Integrated Project, funded by the European Union (EU) within the 6th FP (Framework Program), the conceptual feasibility of high rate MA transmutation in ADS has been demonstrated: this concept reactor is called EFIT (European Facility on Industrial scale Transmuter). It is fuelled by Cer-Cer (Pu, MA)O2-x + MgO fuel type with high content of MA and is cooled by lead. The design constraints for the maximum temperatures of the cladding and of the fuel are satisfied through the power distribution radial flattening techniques. The design of the EFIT core is based on the so called “42–0” approach, characterized by zero Pu net balance and maximum MA transmutation rate of 42 kg/TWhth with reduced BU reactivity loss (~200 pcm/year). Three radial zones, for a total of 180 FAs, at constant Pu/MA mass ratio and with different either pin diameter and/or inert matrix volume fraction, assure the required value for the sub-criticality level Keff = 0.97. The total power of 384 MWth ...
Optimization of the Minor Actinides transmutation in ADS: The European Facility for Industrial Transmutation EFIT-Pb Concept
In the framework of the EUROTRANS Integrated Project the feasibility of an European Facility for ... more In the framework of the EUROTRANS Integrated Project the feasibility of an European Facility for Industrial Transmutation (EFIT) of Minor Actinides (MA) has to be demonstrated and the ADS reactor preliminarily designed. The core is loaded with U-free oxide fuel and cooled by lead. The actual requirements and the optimization criteria led to the so called “42-0” concept. By this approach a zero net balance of Pu is stated while the maximum MA transmutation rate of 42 kg/TWhth is reached, assuring a negligible BU swing of about 200 pcm/year. The about 400 MWth sub-critical core presents three radial zones, different either in pin diameter or in MgO inert matrix percentage, in order to maximize the average density transmutation (≈ 530 W cm-3 on HM) and to respect the cladding temperature limit of 550 °C. The required proton current never exceeds 20 mA at 800 MeV (keff ≤ 0.97). Neutronic calculations have been carried out in ENEA using the deterministic code ERANOS and the Monte Carlo c...
Solution of the equilibrium fuel vector in closed fuel cycles and application to a Lead Fast Reactor
The control system of the Target Carburization prototype for the SPES project
Progress on the characterization of the Direct SPES Target Concept
Progress on the Direct SPES Target Concept
Effect of the beam frequency on the target temperature
The neutronic calculations carried out within the system and safety constraints to define the PDS... more The neutronic calculations carried out within the system and safety constraints to define the PDS-XADS LBE-cooled core are described [Preliminary DesignStudies of an eXperimental Accelerator Driven System, part of the European Commission’s 5th Framework Program for research on Fission Reactor Safety, involving the participation of 25 partners from industry, research organizations and Universities]. The constraints are connected to the peculiar feature of such cores to preserve sub-criticality under all conditions whilst linked to the necessity to maintain a sufficient power level to burn acceptable quantities of MA and LLFP. The power level is held by means of an external source with a spallation target of LBE driven by a proton current maintained at a technologically feasible level. The proton energy is 600 MeV. The reactor circuit power is 80 MWth
Progress on Pellets Production for the SPES Project
Emissivity measurements by a double frequency pyrometer
A new method to measure the thermal conductivity for the SPES project
Uploads
Papers by Carlo Petrovich