A regular monodisperse flow of spherical microtargets of solid hydrogen or deuterium with a variable diameter of several tens of micrometers and a frequency from several tens to several hundreds of kilohertz is in demand as internal targets in physical experiments at accelerators. The paper is devoted to the modification and launching of a prototype cryogenic corpuscular hydrogen target in which the gas entering the facility is transformed into a flow of spherical microtargets. Processes of cryogenic cooling and liquefaction of the gas, formation of a liquid microjet, and its controlled monodisperse disintegration into equal-sized drops are realized in the target, and they are followed by freezing of the drops and formation of microtargets upon injection into vacuum. The target prototype is composed of the cryogenic, vacuum, and gas systems as well as the systems for control and optical diagnostics of microtarget parameters. The modified target prototype provided monodisperse regimes of generation of microtargets with a diameter of 20–50 μm at a generation frequency of 260–465 kHz.

A systematic error is present in reactor calculations performed with the aid of the MCU-code. This paper introduces an algorithm that in calculations by the series method makes it possible to determine the number of neutron generations in the NBAT series and the number of neutrons in the NTOT generation, which reduces the systematic error in the calculation of functionals and their variances. The described procedure includes determining the NBAT-dependence of the standard deviation, repeated calculations of the required functional to refi ne and correct NBAT, and calculations to refi ne NTOT. The algorithm is demonstrated on the example of calculating the effective multiplication factor and fission reaction rates for the VVER-1000 unit cell model with the fuel column divided into 10 layers along the height. It is shown that in order to significantly reduce the systematic error of the local rate of fission reactions it is necessary to play more than 1000 particles in each series and variances in more than 200 series in each neutron generation.

The paper presents an assessment of the effect caused by technological uncertainties on keff using the example of the test problem for a MET1000 fast sodium reactor with metal fuel. It is proposed to perform this assessment using nuclear sensitivity factors by random sampling or direct perturbation without requiring multiple calculations. The TSUNAMI-3D module of the SCALE program was used to analyze the sensitivity to nuclear data uncertainty. The obtained constant and technological uncertainties based on ENDF/B VII.1 equal 1.15 and 0.6

In the PANDA experiment of the FAIR project, it is proposed to use internal targets based on the hydrogen isotopes that provide a monodisperse regime of flow generation of solid spherical pellets with the diameter from 15–40 µm with the frequency from several tens of to several hundred kilohertz. The process for generating the pellets in such facilities includes the cooling, liquefying, and disintegration into drops of the liquid hydrogen jet directed vertically downwards; freezing of the jet when expiring with acceleration into vacuum; and its transport through the vacuum path into the region of interaction with the antiproton beam. For the effective control of the systems of the setup and for the adjustment of generation of pellets, an automatization and control system is developed combining the devices for measurement and control of pellet parameters (temperature, pressure, hydrogen flow, and piezoelectric generator frequency) and the optical diagnostics in a unified computational network. For data exchange between the devices, the TCP/IP Sockets and Modbus TCP protocols are used.

The Panda experiment is a key experiment at FAIR – European Facility for Antiproton and Ion Research, which is in the development stage in Darmstadt (Germany). The physical program of the experiment is focused on the search for exotic particles, research on hadron spectroscopy, the structure of nucleons, nuclear-matter effects, hypernuclei, and in other areas. New experimental forms of matter predicted by theory – glueballs and hybrids – are of great interest. They have not yet been observed. The PANDA facility will be assembled in the storage ring of the HESR antiproton beam. Antiprotons with energy from 1.5 to 15 GeV will be accumulated in the ring. Up to 2·107 interactions/sec are expected on the internal hydrogen (cluster or corpuscular) target. In addition to the high luminosity of the experiment (2·1032 cm–2·sec–1), the beam will be monochromatic. Because of stochastic and electronic cooling, pulsed stretching of the beam is expected to be at the level 10–4–10–5, which makes it possible to measure the mass of the particles with record high resolution 100 keV. Domestic institutes are participating in the development of the PANDA facility.

The thermal heating of aligned nuclear targets of HIO_3, LiIO_3 ans Sb target materials under neutron irradiation at JSNS is considered. It is shown that presently the targets of large volumes (several tens of cm^3) can be used in experiment. The optimal target dimensions are recommended for investigation with resonance neutrons. The use of proposed aligned targets at the new neutron spallation source JSNS (Japan) will make p[ossible to discover TRIV or decrease the present limit on the intensity of parity conserving time violating interaction by two-three order of magnitude.

The concept of preliminary transmutation of minor actinides before placement to the long-term storage is considered. The purpose of such preliminary transmutation before ultimate storage is to incinerate a part of actinides and to transform another part into new actinides providing low level of radiotoxicity accumulated in the storage. Modes of transmutation in reactors of PWR, CANDU, and Superphenix types are compared. Among power reactors, heavy-water PHWR (CANDU) type reactor is most acceptable for preliminary transmutation.

Heavy-water and light-water power reactors can be used for partial transmutation of radwaste. Such transmutation allows us to limit on relatively low level the radiotoxicity accumulated in long-term storage of spent fuel. At transmutation in PHWR-880 reactor operating in the mode of self-service, equilibrium radiotoxicity in storage facility and the time of its achievement are 4–5 times less than for the transmutation in power reactor VVER-1000.

Characteristics of process of transmutation of neptunium, americium and curium from spent nuclear fuel in heavy-water reactor during first 10 lifetimes and at transition to equilibrium mode are calculated. During transmutation, dangerous nuclides, first of all, 244 Cm and 238 Pu are accumulated. They cause an increase of radiotoxicity. At first 10 cycles of transmutation, the radiotoxicity is increased by 8.7 times in comparison with radiotoxicity of initial load of transmuted actinides. Heavy-water reactor with thermal power of 1000 MW can transmute neptunium, americium and curium extracted from 3.7 VVER-1000 type reactors. It means, that the required power of transmutation reactor makes about 8% of thermal power of VVER-1000 type reactors.

Of all the radioactive wastes known in nuclear power industry and engineering, long-lived actinides and fission products from spent nuclear fuel are the most hazardous. One way to reduce their radiation hazard is to resort to nuclear transmutation, which can be performed either in reactors of various types or in accelerator-driven subcritical systems, whose nuclear safety is superior to that of conventional reactors. Fundamentally resolving the problem of the destruction of long-lived radioactive wastes is likely to stimulate progress in the development of the nuclear power industry.

A half-liter two-phase xenon chamber was built and primary and secondary (proportional) scintillation signals were investigated by using α particles. The energy threshold in the chamber was less than 50 keV of electron equivalent and energy resolution was 18%. The value of the spatial ( Z -coordinate) resolution achieved in the time projection chamber was about 0.4 mm.

The paper examines potential changes in the thermal regime and geotechnical properties of permafrost in the permafrost regions of Russia as a result of future climatic warming. The investigations were conducted by mathematical simulation of these processes using a computer program, with increases in annual average air temperature of 2iC and 4iC by the middle of the next century. The entire permafrost region was divided into four geothermal zones based on the degree of sensitivity of frozen soils to thermal actions. The calculations were performed for 4 lines of longitude. The changes in average annual temperature, depth of thaw, long-term strength of frozen soils and bearing capacity of foundations caused by warming were determined for each geothermal zone. As a result, the potential changes in the state and propagation of the permafrost were demonstrated and their possible consequences for the durability of foundations were determined.

Results are given from numerical calculations of the change in temperature conditions of the permafrost layer and its strength properties with possible warming of the air temperature by 2–4°C in the next 60 years. The effect of these changes on the bearing capacity of permafrost soils and the associated stability of structures erected in the permafrost zone is evaluated. Measures that provide for stability of these structures by using the natural cold of the North are discussed. It is taken into account that the natural temperature of the permafrost layer changes in a meridional direction from north to south, and that, in connection with this, the sensitivity of permafrost soil to a thermal action also changes.

On presente des resultats de calculs numeriques relatifs a la modification du regime thermique des pergelisols et de leurs caracteristiques mecaniques, lors d'un rechauffement possible de la temperature de l'atmosphere de 2 a 4 degres C au cours des 60 prochaines annees. On fait une estimation de l'influence de cette modification sur la portance des pergelisols et la stabilite des ouvrages qui y sont construits. On decrit des moyens de maintenir cette stabilite, bases sur l'utilisation du froid naturel du Nord. On tient compte de la variation de la temperature des pergelisols du nord au sud et de la sensibilite concommitante des sols a cette variation.