Nuclear data evaluations are periodically updated to render state of the art of knowledge, and the independent validation experiments are still of interest of the community. Current work describes validation of selected capture reactions used for monitoring of thermal neutrons in mixed fields, as well as reactions responsible for activation of components exposed to neutron flux. The validation was performed also for reaction 50Cr (n,γ), which is very important reaction directly affecting criticality safety, because chromium is essential component of stainless steel used as structural component of the core baffle closely adjoining to nuclear fuel. Described experiments were performed in reference neutron field of the LR-0 reactor. The activation rate was derived by gamma spectrometry using well-characterized HPGe detector. It was found that the capture cross sections for the dosimetry reactions 23Na (n,γ), 58Fe (n,γ), and 59Co (n,γ) agreed well within 10 % with calculations in thermal and epithermal region, but larger discrepancy was found for the isotopes of tin.
- Publikační typ
- časopisecké články MeSH
The spectrum averaged cross sections (SACS) in standard neutron field, e.g. 252Cf(s.f.), is a preferable tool for cross section evaluation and validation. A set of reaction measurements with high energy thresholds was previously performed. The presented work focuses on lower energy threshold reactions, namely on the inelastic scattering of the tin foil, more specifically the reaction 117Sn(n,n')117mSn, and the zinc foil reaction, namely 67Zn(n,p)67Cu. These reactions are of special interest due to their intermediate energy range, which is essential in classical reactor dosimetry and fast reactor dosimetry. The experiments were carried out in a standard neutron field formed by 252Cf(s.f.) source in Řež. The experimental results were compared with calculations using MCNP6.2, ENDF/B-VII.1 transport library, and ENDF/B-VIII.0 and IRDFF-II cross section data library. Additionally, the calculations using CEA code DARWIN/PEPIN2 using JEFF-3.0/A were executed. The obtained experimental SACS of previously measured reactions were in good agreement with the SACS calculated using the IRDFF-II library. Additionally, the calculational reaction rate of 67Zn(n,p)67Cu was in accordance with the experimental data in case of ENDF/B-VIII.0 nuclear data library. Moreover, the calculational results of 117Sn(n,n')117mSn obtained by DARWIN/PEPIN2 code (using JEFF-3.0/A nuclear data library) are closest to the experimental results.
- Publikační typ
- časopisecké články MeSH
Neutron detection using nuclear emulsions can offer an alternative in personal dosimetry. The production of emulsions and their quality have to be well controlled with respect to their application in dosimetry. Nuclear emulsions consist mainly of gelatin and silver halide. Gelatin contains a significant amount of hydrogen, which can be used for fast neutron detection. The addition of B-10 in the emulsion is convenient for thermal neutron detection. In this paper, standard nuclear emulsions BR-2 and nuclear emulsions BR-2 enriched with boron produced at the Slavich Company, Russia, were applied for evaluation of fast and thermal neutron fluences. The results were obtained by calculation from the presumed emulsion composition without prior calibration. Evidence that nuclear emulsions used in the experiment are suitable for neutron dosimetry is provided.
- MeSH
- bor chemie MeSH
- bromidy chemie MeSH
- emulze * MeSH
- fantomy radiodiagnostické MeSH
- helium analýza MeSH
- kalibrace MeSH
- lithium analýza MeSH
- neutrony * MeSH
- počítačové zpracování obrazu MeSH
- radiometrie přístrojové vybavení metody MeSH
- rychlé neutrony * MeSH
- sloučeniny stříbra chemie MeSH
- vodík chemie MeSH
- želatina chemie MeSH
- Publikační typ
- časopisecké články MeSH
The work presents a detailed comparison of calculated and experimentally determined net peak areas of longer-living fission products after 100 h irradiation on a reactor with power of ~630 W and several days cooling. Specifically the nuclides studied are (140)Ba, (103)Ru, (131)I, (141)Ce, (95)Zr. The good agreement between the calculated and measured net peak areas, which is better than in determination using short lived (92)Sr, is reported. The experiment was conducted on the VVER-1000 mock-up installed on the LR-0 reactor. The Monte Carlo approach has been used for calculations. The influence of different data libraries on results of calculation is discussed as well.
- MeSH
- dávka záření * MeSH
- fantomy radiodiagnostické MeSH
- hodnotící studie jako téma MeSH
- hygiena práce MeSH
- ionizující záření MeSH
- lidé MeSH
- metoda Monte Carlo MeSH
- monitorování radiace MeSH
- nemoci štítné žlázy * MeSH
- nukleární lékařství - oddělení nemocnice MeSH
- pacienti * MeSH
- personál nemocniční MeSH
- radiační ochrana MeSH
- radioizotopy jodu škodlivé účinky toxicita účinky záření MeSH
- statistika jako téma MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- kongresy MeSH
- práce podpořená grantem MeSH
The paper is intended to show the effect of a biological shielding simulator on fast neutron and photon transport in its vicinity. The fast neutron and photon fluxes were measured by means of scintillation spectroscopy using a 45×45 mm(2) and a 10×10 mm(2) cylindrical stilbene detector. The neutron spectrum was measured in the range of 0.6-10 MeV and the photon spectrum in 0.2-9 MeV. The results of the experiment are compared with calculations. The calculations were performed with various nuclear data libraries.
