Status of evaluated data files for 238U in the resonance region

Experimental data and evaluated data libraries related to neutron induced reaction cross sections for 238U in the resonance region are reviewed. Based on this review a set of test files is produced to study systematic effects such as the impact of the upper boundary of the resolved resonance region (RRR) and the representation of the infinite diluted capture and in-elastic cross section in the unresolved resonance region (URR). A set of Benchmark experiments was selected and used to verify the test files. Based on these studies recommendations to perform a new evaluation have been defined. This report has been prepared in support to the CIELO (Collaborative International Evaluated Library Organisation) project. The objective of this project is the creation of a world-wide recognised nuclear data file with a focus on six nuclides, i.e. 1H, 16O, 56Fe, 235U, 238U and 239Pu. Within the CIELO project, the Joint Research Centre (JRC) at Geel (B) is in charge of the production of an evaluated cross section data file for neutron induced reaction of 238U in the resonance region.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

Skin color-specific and spectrally-selective naked-eye dosimetry of UVA, B and C radiations

Spectrally–selective monitoring of ultraviolet radiations (UVR) is of paramount importance across diverse fields, including effective monitoring of excessive solar exposure. Current UV sensors cannot differentiate between UVA, B, and C, each of which has a remarkably different impact on human health. Here we show spectrally selective colorimetric monitoring of UVR by developing a photoelectrochromic ink that consists of a multi-redox polyoxometalate and an e− donor. We combine this ink with simple components such as filter paper and transparency sheets to fabricate low-cost sensors that provide naked-eye monitoring of UVR, even at low doses typically encountered during solar exposure. Importantly, the diverse UV tolerance of different skin colors demands personalized sensors. In this spirit, we demonstrate the customized design of robust real-time solar UV dosimeters to meet the specific need of different skin phototypes. These spectrally–selective UV sensors offer remarkable potential in managing the impact of UVR in our day-to-day life

The joint evaluated fission and fusion nuclear data library, JEFF-3.3

The joint evaluated fission and fusion nuclear data library 3.3 is described. New evaluations for neutron-induced interactions with the major actinides $^{235}$U, $^{238}$U and $^{239}$Pu, on $^{241}$Am and $^{23}$Na, $^{59}$Ni, Cr, Cu, Zr, Cd, Hf, W, Au, Pb and Bi are presented. It includes new fission yields, prompt fission neutron spectra and average number of neutrons per fission. In addition, new data for radioactive decay, thermal neutron scattering, gamma-ray emission, neutron activation, delayed neutrons and displacement damage are presented. JEFF-3.3 was complemented by files from the TENDL project. The libraries for photon, proton, deuteron, triton, helion and alpha-particle induced reactions are from TENDL-2017. The demands for uncertainty quantification in modeling led to many new covariance data for the evaluations. A comparison between results from model calculations using the JEFF-3.3 library and those from benchmark experiments for criticality, delayed neutron yields, shielding and decay heat, reveals that JEFF-3.3 performes very well for a wide range of nuclear technology applications, in particular nuclear energy

BETA EFFECTIVE SENSITIVITY TO NUCLEAR DATA WITHIN THE APOLLO3® NEUTRONIC PLATFORM

In this paper, we present a sensitivity analysis of the beta effective to nuclear data for the UM17x17 experiment that has been performed in the EOLE reactor. This work is carried out using the APOLLO3® platform. Regarding the flux calculation, the standard two-step approach (lattice/core) is used. For what concerns the delayed nuclear data, they are processed to be directly used in the core calculation without going through the lattice one. We use the JEFF-3.1.1 nuclear data library for cross-sections and delayed data. The calculation of k-effective and beta effective is validated against a TRIPOLI4® one while the main sensitivities are validated against direct calculation. Finally, uncertainty propagation is performed using the COMAC-V2.0 covariance library

Validation of a Multi-Purpose Depletion Chain for Burnup Calculation through TRIPOLI-4 Calculations and IFP Perturbation Method

International audienceThe current standard depletion chain used by the CEA, called CEA-V5, was validated to treat only LWRs in 2008. This single depletion chain must correctly model the global loss of reactivity for both LWRs and Fast Reactors for future APOLLO3 work on Generation III and IV reactors such as EPR and ASTRID projects milestones. In order to verify the loss of reactivity of the standard CEA-V5 chain, a reference chain with 885 Fission Products (FPs) has been defined and used with the French Monte Carlo code TRIPOLI-4 and its depletion module for comparisons with the standard CEA-V5 chain containing 126 FPs. Three test cases are modeled, a UOX PWR cell, a MOX PWR cell and a MOX SFR cell, to validate the standard chain against the reference one. Results obtained from TRIPOLI-4 can then be used to calculate a loss of reactivity for each case to verify that the standard chain takes into account the majority (ideally 99.9%) of the anti-reactivity of the reference chain. In addition, this loss of reactivity has been decomposed by isotope to rank the FPs by importance using the Iterated Fission Probability (IFP) method recently implemented in TRIPOLI-4

Covariance matrices of the hydrogen neutron cross sections bound in light water for the JEFF-3.1.1 neutron library

International audienceIn the international neutron libraries, the behavior with the energy of the neutron cross sections of hydrogen in light water depends on the thermal scattering laws tabulated in terms of $S$($\alpha$,$\beta$). For the Joint Evaluated Fission and Fusion library (JEFF), Mattes and Keinert have established thermal scattering laws by using the LEAPR module of the NJOY code. However, uncertainties on the corresponding $S$($\alpha$,$\beta$) were never reported. Such missing information was recently calculated with the nuclear data code CONRAD by determining the covariances between the model parameters involved in LEAPR. The obtained uncertainties were propagated to reactivity coefficients calculated for critical assemblies operating in "cold" conditions and for PWR in "hot" operating conditions (300 °C) . For the integral benchmarks investigated in this work, we found that the uncertainty on the calculated $k_{eff}$, due to the $S$($\alpha$,$\beta$) uncertainties, is close to $\pm$130 pcm at room temperature and $\pm$50 pcm at 300°C