Evaluation Of Neutron Data Research Articles

ИСПОЛЬЗОВАНИЕ ПРЯМЫХ ИНТЕГРАЛЬНЫХ ТЕСТОВ СО СТАНДАРТИЗИРОВАННЫМ СПЕКТРОМ ДЛЯ ТЕСТИРОВАНИЯ СЕЧЕНИЯ ЗАХВАТА ОСКОЛКОВ ДЕЛЕНИЯ

The paper presents the results of validation for the capture cross section of the main fission product (FP) nuclides from different neutron data libraries on the results of measurements in integral experiments. A list of the main fission products for various types of fast reactors with various burnups of fuel is defined. When fissioning fuel nuclides in a nuclear reactor, numerous fission products are formed. The most important characteristic of fission products is the neutron capture cross section, as a result of which the valuable neutron for maintaining the fission chain reaction disappears. During long campaigns, the accumulated fission products can lead to a decrease in the criticality of the reactor to ~ 7 %. The evaluated neutron data for the main set of FP nuclides are contained in national libraries of evaluated neutron data. Evaluation of neutron data, as a rule, is carried out on the basis of experimental data from the international EXFOR database using various computational models of nuclear interactions. Often, the evaluated data is very different from each other. Evaluated data can be tested using integral experiments. To test the capture cross section for FP nuclides, direct integral experiments at the CFRMF reactor and experiments in which the neutron spectrum is close to the Maxwell spectrum with a spectrum temperature of kT = 30 keV were used. The first of the above experiments is a dosimetric benchmark experiment, given in the ENDF-202 benchmark experiment handbook. The second type of experiment underlies the recommendations for the MACS capture cross section for nuclides from the KADONiS astrophysical database.

Measurements and evaluation of neutron data for nuclear power generation and other applications

Results which are important for the practice of nuclear power generation have been obtained by purposeful coordinated basic research of a large number of specialists working in different institutes. During this work, a basis for research, methods of measuring nuclear data, and theoretical models of the interaction of neutrons with nuclei were created and data evaluation techniques were developed. The existing and predicted requirements to nuclear data have posed new problems related to an increase in the number of recommended evaluated data, as well as to an improvement of their quality. The work of teams of scientists, who coordinate their activities within the framework of the Commission on Nuclear Data of the State Committee of Atomic Energy of the USSR, must focus on the optimal solution to these problems and on a further increase in the efficiency of the research work.

Statistical model calculations for medium and strong absorption in theA=90 region

Calculations of elastic, inelastic and total neutron cross sections as well as of (p, n) reaction cross sections in theA=90 mass region have been performed, using the statistical model of Hofmann, Richert, Tepel and Weidenmuller. The optical model parameters were obtained by Finckh et al. from the neutron decay of IAR in the91Zr(p, n)91 Nb reaction. The calculations are in very good agreement with the published experimental data. The optical model parameters proved to be satisfactory up to aboutEn=8.0 MeV. The present work might be relevant to the evaluation of neutron data for reactor technology.