[en] Transmuting ²³⁷Np is among the fundamental tasks of minor actinide transmutation. This may be realized by reactor techniques when small admixtures of ²³⁷Np are put in solid fuels of breeders and by the latest technologies that involve continuous ²³⁷Np burnup in a heavy water solution. This solution can be recirculated in subcritical blankets of electronuclear heavy water or molten salt blanket facilities with high energy particle nucleus collisions providing the neutron source. Here, experimental determination of the resonance neutron absorption in a heavy water solution of 2.57 g/ell ²³⁷Np is presented. Experimental samples were irradiated in the MAKET critical plant. Prior to irradiation, ²³⁷Np was radiochemically purified to remove ²³³Pa. The experimental samples were prepared by evaporating two aliquot samples taken from the irradiated solution. The nuclide composition of the samples was analyzed using a GC-2518 Ge detector, a 1510 module, and an S-100 plate to emulate a multichannel analyzer in an IBM personal computer. The spectrometric resolution was 1.8 keV at the 1332-keV line. The gamma spectra were processed by the ASPRO code. The neutron flux was measured by two methods using Al + ⁵⁵MN + ^natCu + ¹⁹⁷Au + ^natLu alloy foils

[en] Possibility for using electric nuclear systems as safety nuclear power units of new generation is treated. Peculiarities of electric nuclear systems as compared with traditional critical reactors is demonstrated by means of comparison of characteristics of the research reactor TBR ITEhF and neutron electric nuclear generator on the basis of TBR and linear proton accelerator ISKRA-36. It is shown that safety of generator is far in excess of safety of TBR

[en] Results of experimental investigation into altitude distributions of ⁶³Cu(n,γ) reaction rates on the external surface of the TVR-M reactor fuel assembly are presented. Investigation is performed to ground the safety of detail design of the 80-100 MW TVR-M channel type heavy water cooled and moderated research reactor. Experiments are conducted at the MAKET critical assembly using a full-scale model of the reactor core. Methods of high-precise γ-spectrometry with NaI(Tl)-detectors are used. Based on the obtained data analysis a conclusion is drawn that an additional. Neutron bakage through horizontal, inclined and vertical channels conditions the general trends in changes of altitude distributions of the investigated reaction rates on the surface of all is fuel assemblies. 8 refs.; 26 figs.; 11 tabs

No abstract available

[en] In this report, the purpose and status of the currently constructed ITEP experimental accelerator driven system (XADS) are discussed. This hybrid electro-nuclear facility of moderate power integrates the pulse proton linac (36 MeV, 0.5 mA) and heavy water sub-critical blanket assembly (heat power of 100 kW). Most parts of the equipment units are ordered for industrial manufacturing and some are under development. The facility is supposed to be used for investigations of a wide range of problems concerning both the target-blanket assembly and the accelerator-driver and at the same time explore the dynamical processes arising during their combined operation. Some other applications of the proton beam and neutron source are also discussed. It is possible in future to increase the current and energy of proton or heavy ion beam. (author)

[en] A neutron generator is planned at the ITEP decommissioned HWR, using the ISTRA linear proton accelerator and a Be target surrounded by a fast neutron multiplication zone (Be, U). Heavy water (moderator, coolant, reflector) secures the high thermal neutron flux. The design of the planned installation is described as well as its calculated performance. 10 figs

No abstract available

[en] The main goal of the Project is to study and evaluate nuclear characteristics of materials and isotopes involved in processes of irradiated nuclear fuel transmutation. This principal task is subdivided into 9 subtasks subject to the neutron or proton source used, the type of the nuclear process under study, isotope collection, characteristics of which are to be investigated, etc. In the presented extract of the Project Activity report the measurements there were used the MAKET zero-power heavy-water reactor in the measurements there was employed a large set of minor actinide samples highly enriched with the main isotope. The samples were obtained with mass-separator SM-2 (VNIIEF). At the heavy-water reactor MAKET (ITEP) there were measured multiplying and kinetic characteristics of salt mixtures basing on the spectra of fast and thermal neutrons. The salt mixtures of zirconium and sodium fluorides were available in salt blanket models (SBM) of cylindrical shape. There were measured the neutron spectra formed by this micro-model as well as the effective fission cross-sections of neptunium, plutonium, americium and curium isotopes caused by SBM neutrons. The neutron spectra in the measurement positions were determined from activation reaction rates. (author)

[en] The work presents the results of determining the blanket subcriticality for a zero-power heavy water reactor MAKET at the Institute for Theoretical and Experimental Physics, Moscow. The blanket is hexagonal lattice made of 36 90%-enriched 235U fuel rods spaced 173mm apart. The subcriticality was varied from ∼0.3% to 5% by adjusting the heavy water level. The subcriticality values were calibrated using the dependence of reactivity on heavy water level. The pulsed neutron source technique was used to measure the temporal dependence of neutron field at different blanket points for the calibrated subcriticality values. The subciticality values obtained in terms of the 'inverse clock' formulae using the decay constants of the measured dependences proved to differ from the calibrated subcriticalities by not more than 7% at the average. The MCNP code-aided simulations of the experiment made has given the calibrated keff values at prescribed heavy water levels and led to the neutron field decay constants at given points, which differ on the average from their experimental values by not more than 7% too. (author)

[en] Experimental and calculated results are presented for the yields of residual nuclei in ⁶³Cu, ⁶⁵Cu, ²⁰⁶Pb, ²⁰⁷Pb, ²⁰⁸Pb, and ²⁰⁹Bi targets irradiated to 1.5 GeV and 130 MeV protons and in ⁵⁹Co target irradiated to 1.2 GeV protons extracted from the ITEP accelerator. The nuclide yields were found by gamma-spectrometry with a GC-2518 Ge detector, a 1510 module, and a S-100 plate that, as an integral part of IBM PC, emulates a multichannel analyzer. The gamma-spectrometry ⁶⁰Co 1332.5 keV line energy resolution was 1.8 keV. The gamma-spectra were processed by the ASPRO code. The SIGMA code with the GDISP radionuclide database was used to identify the gamma-lines and to calculate the respective cross sections. The monitor reactions was ²⁷Al(p,3pn)²⁴Na. The experimental generation cross sections of end products are compared with the respective values calculated by the HETC, INUCL, and CEM95 codes that simulate hadron-nucleus interactions. 12 refs., 3 figs., 7 tabs