•Pa(V) and Np(V) behaviour in HCl and HNO3 with AG1-X8, TEVA, TRU and U/TEVA resins.•Efficient separation of Pa from Np.•Efficient separation of Pa from uranium matrix material.
Literature data on ...distribution ratios (Dw) of Np(V) and Pa(V) for the AG1-X8 resin are scarce whereas those related on resin capacity factors (k′) values for TEVA, TRU and U/TEVA resins are absent. Therefore, batch extraction experiments for Pa(V) and Np(V) from HCl and HNO3 media were realized, at tracer scale, with AG1-X8 and EIChroM resins (TEVA, TRU and U/TEVA). Based on the new Dw and k′ values obtained in this study, a new protocol for Pa/Np separation has been developed leading to a better separation factor of 105 and a chemical yield of 97±3% and 99±1% for Pa and Np, respectively. A separation of 231Pa from uranium matrix was successfully tested.
Part I of this publication deals with the analysis of fission product releases consecutive to the Fukushima Dai-ichi accident. Reactor core damages are assessed relying on radionuclide detections ...performed by the CTBTO radionuclide network, especially at the particulate station located at Takasaki, 210 km away from the nuclear power plant. On the basis of a comparison between the reactor core inventory at the time of reactor shutdowns and the fission product activities measured in air at Takasaki, especially
95
Nb and
103
Ru, it was possible to show that the reactor cores were exposed to high temperature for a prolonged time. This diagnosis was confirmed by the presence of
113
Sn in air at Takasaki. The
133
Xe assessed release at the time of reactor shutdown (8 × 10
18
Bq) turned out to be in the order of 80 % of the amount deduced from the reactor core inventories. This strongly suggests a broad meltdown of reactor cores.
The present work reports on a long-term analysis of the performances of the 95Zr/95Nb chronometer for dating a nuclear event. Taking benefit of a recent Profiency Test Exercise, a sample containing a ...standardized mixture of fission products has been measured repeatedly with a low background HPGe spectrometer during a period extending up to one year with the aim of assessing the accuracy of the various zero-time determinations. Evaluation of the uncertainties associated to these evaluations was performed using a Monte Carlo approach. Input parameters sensitivity has been investigated, especially the influence of the 95mNb decay branch. The 95Zr/95Nb chronometer was found to be accurate for zero-time determination within one day and one week for a decay of 3 months and 10 months respectively. Sub-day uncertainties are achievable for a two months old sample whereas sub-week uncertainties are reached after a decay of six months. Limitations of the technique for dating a real event are investigated.
•An air filter spiked with fission products was analyzed by gamma-ray spectrometry.•T0 of the fictitious nuclear explosion was determined using 95Zr/95Nb chronometer.•Very accurate dating can be obtained even after several months of decay.•To avoid GUM limitations, uncertainties were assessed using Monte Carlo simulation.•Practical limitations of this chronometer in actual situations are investigated.
We present the results of the activity measurement of a sample of the rare isotope
176Lu, obtained by
γ
-ray spectrometry through the use of 22 peaks in an energy spectrum acquired with a 300
cc ...well-type HPGe detector located in the Modane underground facility below the French Alps. Of the above peaks, 17 are coincidence peaks between two or three
γ
-rays or X-rays. True coincidence summing corrections were made using our Coincal code. Monte Carlo simulations were carried out for calibration purposes.
High-resolution dual X and gamma spectrometry has been optimized to improve the sensitivity in analyzing radioxenon from environmental samples, especially for the metastable isotopes (131Xem and ...133Xem). The full-energy peak (FEP) efficiency curve in the 20-700 keV range has been established with a global uncertainty better than +/-3% using a Monte Carlo simulation. The minimum detectable activity concentrations (MDC) achievable at the laboratory for 131Xem, 133Xem, 133Xe and 135Xe are presented and the influence of 133Xe activity on the metastable radioxenon MDCs is evaluated.
The present work reports on a long-term analysis of the performances of the super(95)Zr/ super(95)Nb chronometer for dating a nuclear event. Taking benefit of a recent Profiency Test Exercise, a ...sample containing a standardized mixture of fission products has been measured repeatedly with a low background HPGe spectrometer during a period extending up to one year with the aim of assessing the accuracy of the various zero-time determinations. Evaluation of the uncertainties associated to these evaluations was performed using a Monte Carlo approach. Input parameters sensitivity has been investigated, especially the influence of the super(95m)Nb decay branch. The super(95)Zr/ super(95)Nb chronometer was found to be accurate for zero-time determination within one day and one week for a decay of 3 months and 10 months respectively. Sub-day uncertainties are achievable for a two months old sample whereas sub-week uncertainties are reached after a decay of six months. Limitations of the technique for dating a real event are investigated.
The generalized forward spin polarizabilities gamma(0) and delta(LT) of the neutron have been extracted for the first time in a Q2 range from 0.1 to 0.9 GeV2. Since gamma(0) is sensitive to nucleon ...resonances and delta(LT) is insensitive to the Delta resonance, it is expected that the pair of forward spin polarizabilities should provide benchmark tests of the current understanding of the chiral dynamics of QCD. The new results on delta(LT) show significant disagreement with chiral perturbation theory calculations, while the data for gamma(0) at low Q2 are in good agreement with a next-to-leading-order relativistic baryon chiral perturbation theory calculation. The data show good agreement with the phenomenological MAID model.
We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton. The kinematic point (theta_lab = 12.3 degrees and Q^2=0.48 (GeV/c)^2) is ...chosen to provide sensitivity, at a level that is of theoretical interest, to the strange electric form factor G_E^s. The result, A=-14.5 +- 2.2 ppm, is consistent with the electroweak Standard Model and no additional contributions from strange quarks. In particular, the measurement implies G_E^s + 0.39G_M^s = 0.023 +- 0.034 (stat) +- 0.022 (syst) +- 0.026 (delta G_E^n), where the last uncertainty arises from the estimated uncertainty in the neutron electric form factor.
High-resolution dual X and gamma spectrometry to improve the sensitivity in analyzing radioxenon from environmental samples, especially for the metastable isotopes was optimized. The full-energy peak ...(FEP) efficiency curve in the 20-700keV range was established with a global uncertainty better than plus or minus 3% using a Monte Carlo simulation. The sensitivity of super(133)Xe super(m) was only improved by a factor close to 1.4 and led to a minimum detectable activity concentrations (MDC) of about 0.9 mBq/m super(3). The MDC achievable at the laboratory for super(131)Xe super(m), super(133)Xe super(133)Xe, and super(135)Xe were presented and the influence of sub(133)Xe activity on the metastable radioxenon MDCs were evaluated. It was concluded that super(131)Xe super(m) MDC calculated from the X-rays is better than those calculated from gamma -rays provided the activity of super(133)Xe is smaller than 500 mBq/m super(3).
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