Plutonium Isotopes Research Articles

Actinide and non-actinide production from UO2 fuel in W-SMR: Effects of gadolinium burnable absorber

Burnable neutron absorbers are used for efficient reactivity control especially in light and heavy water reactors. Effect of gadolinium burnable absorber (GdBA) on reactivity, actinide and non-actinide content of nuclear waste was investigated. Westinghouse small modular reactor (W-SMR) was studied using MCNPX 2.7 code integrated with CINDER90 for the calculations. Positive reactivity swing was observed in fuel assemblies with GdBA rods. The concentration of actinides was relatively higher in FA without GdBA rod compared to those with GdBA rods. The net activity of 241Pu and 239Np were respectively higher compared to other isotopes of plutonium and neptunium and slightly larger in FAs with GdBA rods. However, a significant increase on the concentration of non-actinide inventory was observed which increased with the number of GdBA rods. Therefore, the use of GdBA for reactivity control should be limited to avoid unrealistic reactivity swing and increased non-actinides content of the spent fuel.

Investigations of the fresh-core cycle-length and the average fuel depletion analysis of the NuScale core

Fresh cores with a few changes on the fuel enrichment and/or gadolinium content of the Fuel Assemblies (FAs) are proposed for a typical PWR-Small Modular Reactor called NuScale. Many neutronics as well as Thermal Hydraulics (TH) Core Design Basis Limits for the first-cycle of the proposed fresh core are fully studied and verified herein. In addition, the coupled TH-neutronic calculations of the core are performed using RELAP5-MCNP codes. The burnup calculation for the core is performed using MCNPX 2.7 to investigate the core first-cycle-length. The excess reactivity as well as power peaking are studied to find the first-cycle-length. Average core fuel depletion are also taken into account; and masses of produced fission fragments and build up plutonium isotopes as well as the remained mass of uranium isotopes (and Gd) are computed at the EOC (first cycle of 730 days).

Minor actinide transmutation in the lead-cooled fast reactor

The minor actinides are introduced to a lead-cooled fast reactor (LFR) core in three different approaches to study minor actinide (MA) transmutation characteristics. Power peaking factor calculation results indicate that loading appropriate amount of minor actinide to LFR core does not disturb the neutron flux distribution or power density distribution in LFR core remarkably. This is an advantage of transmutation minor actinides in LFR compared to the minor actinide transmutation characteristics in the PWR reactor.After MA loading to LFR, keff curves deviate from keff curves without minor actinides loading obviously; there is no distinct difference between keff curves of three minor actinide loading approaches. The LFR core loaded with minor actinides can prolong the fuel cycle to some extent. This is because the created new fissile 238Pu, 242Am, 244Am, 243Cm and 245Cm can compensate the reactivity loss due to the consumption of nuclear fuel and sustain the criticality of LFR core.After minor actinide 550-day-exposure in LFR, the concentration of 237Np, 241Am and 243Am decreases, while the concentration of 244Cm and 245Cm increases. This is because the 241Am and 243Am capture neutrons and generate 244Cm and 245Cm. The lead-cooled fast reactor with the thermal power of 750 MW and loading 1 wt % MA nuclides can consume the annual minor actinide yields from about 1.5 typical PWRs. The fraction of plutonium isotopes from LFR reactor spent fuel after MA transmutation is about 85%, the rest being made up of other transuranic isotopes. Plutonium isotopes are important nuclear fuel. Most importantly 238Pu is a very powerful alpha particle emitter; this makes 238Pu an ideal material for fabricating radioisotope batteries.In general, transmutation of minor actinides in lead-cooled fast reactors can achieve the goals of elimination of MA nuclide long term radioactive hazards and creation of important 238Pu material. Therefore, it is feasible to transmute the MA nuclide in lead-cooled fast reactors.

Adaptation of the Method of Radiochemical Determination of Plutonium Isotopes in Soil from the Semipalatinsk Test Site

Presents the results of work to determine the optimal conditions for chemical extraction of samples; solutions are described to minimize the loss of the target radionuclide in the process of chemical separation; the factors influencing the completeness of plutonium isotope precipitation were experimentally determined and eliminated.

Sources and variation of isotopic ratio of airborne radionuclides in Western Arctic lichens and mosses

This research concerned radioactivity of lichens and mosses from coastal zones of the Canadian Arctic and Alaska. Over 50 samples were collected from 7 positions during two scientific expeditions in 2012 and 2013. The tundra contamination caused by anthropogenic radionuclides was relatively low, reaching mean values with SD's of: 17.4 ± 3.5 Bq/kg for 90Sr, 14.0 ± 2.9 Bq/kg for 134Cs, 38.4 ± 7.5 Bq/kg for 137Cs, 0.86 ± 0.24 Bq/kg for 239+240Pu, 0.065 ± 0.017 Bq/kg for 238Pu and 0.50 ± 0.13 Bq/kg for 241Am. The increase of activity concentration with increasing latitudes was noticed mostly in regard to 90Sr, Pu isotopes and 241Am. The analysis of isotopic ratios exhibited dominant contribution of the global fallout (+SNAP 9A satellite re-entry fallout) for the presence of plutonium isotopes and 241Am. The Fukushima fallout signature was identified in a few lichens from Alaska. However, the influence of additional unknown factor on the occurrence of 90Sr and 137Cs has been detected in western part of Canadian Arctic. Natural radioisotopes of thorium and uranium were found throughout the entire investigated region and the average values of activity concentration with SD's were as follows: 2.92 ± 0.47 Bq/kg for 230Th, 2.61 ± 0.48 Bq/kg for 232Th, 4.32 ± 0.80 Bq/kg for 234U and 3.97 ± 0.71 Bq/kg for 238U. Examined Western Arctic tundra was not affected with any technically enhanced natural radioactivity.

Determination of Femtogram-Level Plutonium Isotopes in Environmental and Forensic Samples with High-Level Uranium Using Chemical Separation and ICP-MS/MS Measurement.

ICP-MS is becoming a competitive technique for measurement of plutonium isotopes. Besides the abundance sensitivity (tailing of 238U to m/z = 239 and 240), isobaric and polyatomic ions interferences (e.g., 238U1H+) are the most critical challenges for determination of low-level plutonium in high uranium samples. This work presents a new method to solve this problem using ICP-MS with two tandem quadrupole separators and a dynamic collision/reaction cell combined with chemical separation. The interference of uranium hydrides (238U1H+ and 238U1H2+) was effectively eliminated using CO2 as reaction gas by converting hydrides to oxides of uranium ions (UO+/UO2+) but still keeping the intensity of the Pu+ signal. The tailing interference of 238U+ (abundance sensitivity) was intensively eliminated by significantly suppressing the 238U+ signal using CO2 as reaction gas and using two tandem quadrupole mass separators in the ICP-MS/MS. With these approaches the overall interference of uranium was reduced to <1 × 10-8, which is 3 orders of magnitude better than the conventional ICP-MS. Combined with chemical separation with a decontamination factor of 105 for uranium, an overall factor of 1012 for elimination of uranium interference was achieved. The developed method was demonstrated to enable accurate determination of <10-15 g/g level plutonium isotopes in environmental samples even in a uranium debris sample with a U/Pu atomic ratio of up to 1012. The developed method was validated by analysis of a spiked solution and certified reference materials of soil.

Environmental behaviour of radioactive particles from chernobyl

Long-term environmental behaviour of radioactive particles released during the Chernobyl accident and deposited in sandy topsoil in Ivankiv district of Kyiv Region (Ukraine), in radioactive trench waste materials from the Red forest, and in bottom sediments from the Cooling pond has been assessed. The efficiency of the models describing the dissolution/weathering rates of U fuel particles developed 15–20 years ago was tested, and their predictions for the dynamics of remobilization, mobility and plants uptake of 90Sr were confirmed.It was found that at present in the topsoil and in radioactive trench waste material, total dissolution of fuel particles of low chemical stability (UO2+x) has occurred and about half of the non-oxidized chemically stable fuel particles (UO2) has also dissolved, indicating radiological stabilization of the environment and that the mobile fraction of radionuclides would be reduced in the future. The biological availability of 90Sr in topsoil due to fuel particles dissolution has reached maximum values and further decrease is expected.The presence of chemically extra-stable fuel particles (U-Zry-Ox) in environments should be taken into account when the total radionuclides activity concentrations are assessed during radioactive materials management.It was shown that nearly half of the 90Sr activity remained as part of the non-dissolved UO2 fuel particles at the time of the study. Taking into consideration that 31 ± 4% of the radionuclide activities were still associated with non-dissolved chemically extra-stable particles (U-Zry-Ox) in radioactive trench waste materials from the Red forest, increased dissolution should not be expected in the near future.The physico-chemical form of radionuclides in air exposed sediments from the Cooling pond were determined, and results showed that about 70–80% of total 90Sr, 241Am and plutonium isotopes activity were associated with U fuel particles. The low dissolution rate of radionuclides from the pond sediments is attributed to prolonged slightly alkaline pH in the medium due to zebra mussel residues.According to new data, the emission value of 238Pu associated with fuel particles released during the Chernobyl accident amounted to 1.8 × 1013Bq (1.2% of the activity in the reactor) and 90Sr amounted to 2.6 × 1015Bq (1.5% of the activity in the reactor).

Investigation on the effect of 238U replacement with 232Th in small modular reactor (SMR) fuel matrix

Effect of 238U replacement with 232Th in small modular reactor fuel matrix was studied. Four different 235U enrichment levels (10, 13.8, 16.5 and 19.8 wt%) were used in a pairwise manner for UO2 and (ThO2 + 235U) fuels. The calculation was performed using Monte Carlo N-particle code integrated with CINDER90 for burn-up calculations in a homogeneous fuel assembly. The results show that enrichment level <17 wt% for thorium fuel produced virtually no plutonium isotopes but became visible only at 19.8 wt% enrichment. The number of neutrons produced per fission (ν) for ThO2 + 235U was less than that of UO2 because its averaged contribution from 235U and 233U was smaller compared to the similar contribution from 239Pu, 241Pu and 235U. Large amount of 239Pu and actinides were produced from UO2 fuel due to the impact of 238U. The reactivity of thorium at the beginning of cycle (BOC) was smaller compared to uranium but higher at end of cycle (EOC) resulting to higher excess reactivity in all thorium fuel. Production of little plutonium isotopes by thorium fuel suggests that it would make a good proliferation resistance fuel and could be used in any W-SMR to incinerate stockpiled plutonium.

СРАВНЕНИЕ ГОМОГЕННОГО И ГЕТЕРОГЕННОГО ИСПОЛЬЗОВАНИЯ ЭНЕРГЕТИЧЕСКОГО ПЛУТОНИЯ В ВВЭР

There are separate of fissile isotopes in a fuel rod in the fuel load admit the transition to a closed fuel circle in the nuclear power industry. For this solution to consider the formation of heterogeneous fuel pellet in which the fissile and raw isotope are separate and not mixed together. The raw material isotope is located in the peripheral zone. Fissile isotope, placed in the center of fuel pin holds 10% of the volume. There is row isotope in the periphery. All calculations for this research were made with UNK code. This code was complemented with a module, which allows calculating temperatures in pin cell. At present UNK allows solving of neutron-physical task of neutron transport, burn-up task (isotope composition evolution) and temperature calculation. Initial loading is plutonium, separated from spent fuel of the same cell of previous company. Irradiated plutonium of the central part is sent to either long term storage or final disposal. Energy plutonium location extracted from spent fuel of VVER in the central part of fuel pellet (heterogeneous pellet) decreases plutonium loading approximately 20 % in condition of the same company duration in comparison with UOX fuel. In case of heterogeneous location, there is depleted uranium in the periphery on the pellet. And after irradiation received plutonium isotope composition can be used repeatedly to form new loadings. This solution is qualitatively different from MOX case, which does not allow further using.

A new fuel depletion code based on group-wised energy Bateman ODEs; SUDEPLET code for point-like PWR core

A new efficient fuel depletion code for the PWRs (containing less than 5% average enrichment) is developed based on the Bateman five-energy groups coupled ODEs, and is called SUDEPLET (Shiraz University DEPLETion code). In the current article, SUDEPLET physical concepts and its approximation procedures are given, and also the SUDEPLET.exe file are attached and released as user friendly software without any limiting-access. The SUDEPLET execution schemes and inputs are explained, and the SUDEPLET is executed for three different suggested PWRs to find its verification. The SUDEPLET results (which include more than 200 tracked isotopes) are benchmarked with those results using other familiar fuel depletion analyzers such as ORIGEN 2.1 and/or MCNPX 2.6 (based on the BURNS card). Lack of a complicated input is the main improvement of the SUDEPLET code. Actually, thermal power, the BOC uranium isotopes masses, and cycle-time (in terms of days) are the main necessary input parameters for SUDEPLET executions. Another capability of the SUDEPLET is its ability to calculate the whole core average EXCESS reactivity due to uranium depletion of the core, temperature defects, and mixed burnable poisons in the fuel (or BARs). Among hundreds tracked isotopes; Cs-131, Cs-135, Cs-137, Sr-90, Tc-99, I-129 (which are problematic isotopes in the High Level Waste analysis); also Am-241 and Np-237 (which are most important problematic actinides in the HLW analysis) are highlighted and tabulated in the “Principle Window” of the SUDEPLET. Obviously, time-dependent uranium and plutonium isotopes masses are the main elements which are tracked during the cycles.

Radioactive particles in the Yenisei River floodplain (Russia): Characterization, leaching and potential effects in the environment

The operation of the Mining-and-Chemical Combine (MCC), the largest producer of weapons-grade plutonium in Russia, has resulted in radioactive contamination of the Yenisei River floodplain. Investigations carried out in Novosibirsk and Krasnoyarsk institutes have shown that the floodplain of the Yenisei downstream of the MCC is contaminated by radioactive particles (RP) of various types and activities. Analytical characterization of the RP showed that most of them were fuel particles, which were carried into the Yenisei after incidents at the MCC reactors. The plutonium and caesium isotope ratios (238Pu/239,240Pu; 137Cs/134Cs) vary substantially between the particles, indicating different source terms and time intervals when the RP were formed. In addition to fuel RP, there were particles that contained activation radionuclides. The experiment on dissolution of RP using the model solution (the simulated stomach fluid) showed different cumulative extractions of radionuclides from the particles: 60Co and 137Cs extractions were the lowest, the extracted fractions of europium and americium isotopes were the largest, and plutonium occupied an intermediate position. High concentrations of radionuclides in RP are sources of exposure of organisms in aquatic and terrestrial ecosystems to low radiation doses. The plant bioassays of the effects of γ-radiation from RP showed the effect of low doses of γ-radiation on growth parameters of aquatic plant Elodea canadensis growing in the Yenisei River floodplain. The presence of RP from different sources in the Yenisei River floodplain makes this region a unique site for studying environmental effects of the particles.

Level, distribution and sources of plutonium in the coastal areas of China

Plutonium is an important radioactive element in view of its biological toxicity and environmental impact. The two most important isotopes of plutonium, 239Pu and 240Pu, in the surface soil from the coastal area of China were determined using radiochemical separation combined with inductively coupled plasma mass spectrometry (ICP-MS) measurement. The average of the measured 240Pu/239Pu atomic ratios in all these samples is 0.186 ± 0.021, which is in good agreement with the ratio of global fallout of the nuclear weapons tests. This indicates that the major source of plutonium in this region is global fallout, and there is no measurable release of plutonium from any nuclear power plant along the coast of China. The 239,240Pu concentrations in all 71 soil samples range from 0.002 mBq/g to 0.670 mBq/g, which fall in the range of the reported values in the background area not directly influenced by nuclear activities. The anthropogenic disturbance of sampling sites, vegetation coverage of land, precipitation rate and organic substance content and erosion of soil have significant influence on the level of plutonium in the surface soil.

Comparison of BWR fuel assembly options for minor actinide recycling

Nuclear energy production generates Minor Actinide (MA) and Plutonium (Pu) isotopes, being these ones the main reason for the longtime storage of the depleted fuel assemblies. A reduction of these produced isotopes will decrease the volume required for their storage and their total elimination could eventually decrease the storage time. A possible alternative for MA reduction is recycling them into Boiling Water Reactor (BWR) cores. It is proposed that the corresponding BWR fuel assemblies into these cores will contain 4 MA bearing-rods. For this purpose a Uranium Oxide (UO2) fuel assembly or a Mixed Oxide (MOX) fuel assembly can be used. For the MOX fuel assembly two types of fuel assemblies are used, the first one only considers the replacement of 4 MOX rods by 4 MA-bearing rods and the last one considers also increasing the fuel-to moderator ratio by the replacement of 8 MOX fuel rods by water rods. The behavior of the designed fuel assemblies is compared against a reference UO2 standard 10x10 BWR fuel assembly. Results show the MA and Pu reduction achieved by the use of each one of the four proposed assemblies. Advantages and disadvantages of the recycling using each one of the fuel assemblies are discussed.

Study of fission dynamics with a three-dimensional Langevin approach

The three-dimensional Langevin model plus a constraint on the heavy fragment deformation is used to study the fission dynamics for uranium and plutonium isotopes at low excitation energies. The potential energy surface is calculated with the macroscopic-microscopic model based on the two-center shell model. The Werner-Wheeler approximation is used to calculate the inertia tensor and the wall-and-window model is applied to calculate the friction tensor. In this work, the influence of the model parameters on the fission fragment mass distribution is investigated. The fission fragment mass distributions for $^{234,236,239}\mathrm{U}$ and $^{240}\mathrm{Pu}$ at low excitation energies are calculated and compared with the results of gef code as well as the evaluated data of ENDF/B-VIII.0. A nice agreement is found in the comparison, in which the incorporation of the constraint on the heavy fragment deformation plays an important role. In addition, the dependence of the mass distribution on the excitation energies for $n+^{235}\mathrm{U}$ fission is also studied within the model. Furthermore, the correlation between the elongation and mass asymmetry at the scission point and the correlations of the fission time with both the elongation and mass asymmetry are studied. This study may shed light on understanding the dynamics of the superlong channel for symmetric fission and the standard channels for asymmetric fission in the gef model and other phenomenological fission models.

Evaluation of soil erosion and ecological rehabilitation in Loess Plateau region in Northwest China using plutonium isotopes

Soil erosion is a critical threat to the agriculture and ecosystem in the Chinese Loess Plateau area. Ecological rehabilitation has been applied in large area for reduction of the soil erosion. Six soil depth profiles were collected from Nanxiaohegou watershed in the Loess Plateau in northwest China and analyzed for the activity concentrations of plutonium isotopes. The measured 240Pu/239Pu atomic ratios in all these samples (0.186±0.017) showed that the global fallout was the dominant source of plutonium in this region. An exponential decline of 239,240Pu activity concentrations with depth was observed in most of soil profiles. The total inventory of 239,240Pu in the reference site was calculated to be 110 Bq/m2, agreeing well with the reported total fallout value in this latitude. The soil erosion rates were estimated by comparison with the reference site to be 538–941 t/km2/yr in the most of sites. While an excessive inventory of 239,240Pu (186 Bq/m2) compared to the reference site was observed in one site in the base area, indicating a significant accumulation of soil occurred in this area. The soil erosion depths were estimated to be 2.4–4.6 cm in most of sites during 1963–2016, which can be classified as minor erosion. Compared with the erosion rates in the Nanxiaohegou watershed in 1963–2012 which was estimated by other methods, it is suggested that the natural grass is better for long-term ecological restoration, especially in slope area.

Comparative Analysis on Fuel Breeding for Less Moderation Ratio of Water Cooled Reactor

Nuclear fuel breeding aspect of water-cooled reactor become one of the important issues to extend the sustainability aspect of nuclear fuel in line with fast breeder reactor program with closed fuel cycle concept. In the present study, nuclear fuel sustainability aspect of conversion ratio, several fuel-recycling schemes, nuclear fuel composition and isotopic plutonium composition have been evaluated based on a water-cooled reactor of light water (H2O) and heavy water (D2O) as coolants for less ratio of moderator to fuel (MFR). Less fissile content is required for plutonium (Pu) recycling scheme than once through scheme for both coolant types and it requires more fissile content for heavy water coolant (D2O) of U-235 than light water coolant for both fuel cycle schemes. Plutonium recycling scheme obtains higher fuel conversion ratio than once through for both coolant types and more fuel conversion ratio is shown by heavy water coolant than light water coolant. It shows near fuel breeding can be obtained by light water coolant and breeder reactor capability can be obtained by heavy water coolant. Higher composition of trans-uranium including plutonium and minor actinides (MA) are shown by plutonium recycling case and heavy water coolant, which is estimated that can contribute to have more fuel-breeding capability. Composition of plutonium and americium increases significantly for heavy water coolant, while neptunium and curium compositions are almost the same for both coolants. Plutonium recycling scheme and heavy water coolant produces more even mass plutonium isotopes such Pu-238, Pu-240 and Pu-242 as fertile material, which can be estimated to give better fuel breeding capability and higher level proliferation resistant.

Advanced BWR criticality safety part II: Cask criticality, burnup credit, sensitivity, and uncertainty analyses

In this study, an analysis on burnup credit for cask criticality safety in BWR spent fuel is conducted. Accurate burnup credit can be used to reduce overly conservative safety margins to increase shipping and storage efficiency while maintaining criticality level within regulatory limits. This analysis is based on advanced lattice depletion models that capture various complexities associated with BWR operation. This paper describes the second part of the two-part study which performs an out-of-core analysis of spent fuel in a transportation/storage cask. The first part of the study (Radaideh et al., 2019) developed the set of depletion models used here. In this paper, the spent fuel compositions resulting from these depletion models are used for cask criticality calculations. Uncertainty quantification of cask keff is performed by combining the uncertainty in isotope inventory, nuclear data, and the statistical sampling in KENO-V.a. The uncertainty in isotopic inventory is quantified by performing a validation analysis by comparing spent fuel compositions calculated by 2D TRITON to experimentally determined spent-fuel assay data for three reactors: Fukushima Daini-2, Cooper-1, and Gundermmingen-A. The validation results demonstrate good agreement for the uranium isotopes as compared to the plutonium isotopes. Also, it was found that the uncertainty in cask keff is dominated by the isotopic uncertainty and can reach about 2500 pcm, and as low as about 1700 pcm. Final results show that axial power profile, axial coolant density, control rod modeling, and the presence of gadolinium in 3D simulations have the largest effects on BWR burnup credit. This implies the need for detailed 3D modeling for accurate BWR burnup credit analysis. In addition, based on the UQ analysis considering both actinide only and actinide and fission products sets, the cask remains subcritical within 2σ for all depletion cases analyzed (C0-C9), even though the cask is assumed to be flooded with water and the lattices are discharged at their peak reactivity.

Nuclear Fuel Cycle with Minimized Waste

A uranium-based nuclear fuel and fuel cycle are proposed for energy production. The fuel composition is chosen so that during reactor operation the amount of each transuranic component remains unchanged since the production rate and nuclear reaction rate are balanced. In such a ‘balanced’ fuel only uranium-238 content has a tendency to decrease and, to be kept constant, must be sustained by continuous supply. The major fissionable component of the fuel is plutonium is chosen. This makes it possible to abandon the use of uranium-235, whose reserves are quickly exhausted. The spent nuclear fuel of such a reactor should be reprocessed and used again after separation of fission products and adding depleted uranium. This feature simplifies maintaining the closed nuclear fuel cycle and provides its periodicity. In the fuel balance calculations, nine isotopes of uranium, neptunium, plutonium and americium are used. This number of elements is not complete, but is quite sufficient for calculations which are used for conceptual analysis. For more detailed consideration, this set may be substantially expanded. The variation of the fuel composition depending on the reactor size is not too big. The model accounts for fission, neutron capture and decays. Using MCNPX numerical Monte-Carlo code, the neutron calculations are performed for the reactor of industrial nuclear power plant size with MOX fuel and for a small reactor with metallic fuel. The calculation results indicate that it is possible to achieve criticality of the reactor in both cases and that production and consuming rates are balanced for the transuranic fuel components. In this way, it can be assumed that transuranic elements will constantly return to such a reactor, and only fission products will be sent to storage. This will significantly reduce the radioactivity of spent nuclear fuel. It is important that the storage time for the fission products is much less than for the spent nuclear fuel, just about 300 years.

Alpha spectrometry with the inexpensive open-source detector Alphaino

Abstract A photodiode-based inexpensive detector working as counter and spectrometer for alpha particles , named Alphaino , is described and analyzed in depth. Prior to detector construction, Monte Carlo simulations by means of MCNPX ver. 2.7.0 code have been carried out to select the most suitable sensitive element for the intended applications. The detector has been tested for low-rate alpha-particle counting and spectroscopy , demonstrating a maximum achievable count rate of 4 ⋅ 1 0 3 s−1, with an energy resolution corresponding to a Full Width Half Maximum of 160 keV over the entire energy range of measured alpha, namely 4 − 6 . 5 MeV, the intrinsic efficiency being 100%. Alphaino can be used for fast and qualitative analyses to radionuclides identification, and quantitative analyses when radionuclides monitored are characterized by well distinguished energy lines in spectra. Its applications will include 222 Rn progeny monitoring by mechanical air sampling on a millipore filter, and disposable applications to qualitative measuring of potentially alpha-contaminated liquids (containing plutonium isotopes) by a droplet put on the photodiode itself, for a quick and cheap evaluation prior to initiate proper chemical treatments to classical alpha spectrometry by electrodeposition . Alphaino is completely open-source. The repository for the project is available on GITHUB at https://github.com/bemxgm/Radon-Monitor .

Measurement of the 242Pu(n,f) cross-section at the CERN n_TOF facility

Knowledge of neutron cross-sections of various plutonium isotopes and other minor actinides is crucial for the design of advanced nuclear systems. The 240,242Pu(n,f) cross-sections were measured at the CERN n_TOF facility, taking advantage of the wide energy range (from thermal to GeV) and the high instantaneous flux of the neutron beam. In this work, preliminary results are presented along with a theoretical cross-section calculation performed with the EMPIRE code.