Role of separate factors in the development of the chernobyl accident

NIKIÉT. Translated from Atomnaya Énergiya, Vol. 75, No. 5, pp. 336-341, November, 1993.     

Radiation Embrittlement of VVÉR-1000 Vessel Materials

Radiation embrittlement of VVÉR-1000 vessel materials has been studied much less than for VVÉR-440 reactors. In the present paper the results of an investigation of the first batches of control samples of VVÉR-1000 vessel materials are discussed. The chemical composition of the materials is characterized by a low content of harmful impurities (copper and phosphorus) and a high nickel content (up to 1.9% in some weld seams). The actual rate of radiation embrittlement of the material studied is comparable to the embrittlement calculated using the Russian standards. The dependence of radiation embrittlement of VVÉR-1000 vessel materials on the metallurgical variables and the damaging dose is studied. The investigation showed that nickel greatly intensifies the radiation embrittlement. New relations were developed for determining the actual rate of radiation embrittlement of VVÉR-1000 reactor vessel materials and assessment of its conservativeness.     

Initial ion charge of a fission fragment

FÉI. Translated from Atomnaya Énergiya, Vol. 73, No. 2, pp. 146-153, August, 1992.     

Application of the leak-before-break concept in nuclear power plant safety analysis

NIKIÉT. Translated from Atomnaya Énergiya, Vol. 75, No. 6, pp. 426-430, December, 1993.     

Radiation-induced swelling of zirconium hydride

Physics and Energy Institute (FÉI), Obninsk. Translated from Atomnaya Énergiya, Vol. 71, No. 2, 178–180, August, 1991.     

Transmutation of Americium in a Heavy-Water Reactor

It is shown that 22.5 metric tons of americium from the spent fuel of 30 VVÉR reactors which operated for 30 yr can be transmuted in a 1 GW(t) heavy-water system in 103 yr using as fuel the plutonium from the same spent VVÉR fuel. This means that 7.5 VVÉR reactors (CUF = 0.85) must be maintained simultaneously for fuel storage time 30 yr (for a 3-yr fuel storage period, the number of VVÉR reactors maintained increases to 25). In the entire period of operation of the system, a substantial quantity of plutonium from the spent fuel is used – about 150 metric tons (with total plutonium production in VVÉR reactors of about 200 metric tons) and about 38 metric tons of fissioning isotopes are burned. Therefore, with up to 98% burnup of americium in the target material the conversion coefficient defined as the ratio of the mass of the americium annihilated to the mass of the spent fissioning material is about 0.57.     

Measurements of the fission cross section ratios232Th/235U and234U/235U for 0.13–7.4 MeV neutrons

Power Physics Institute (FÉI). Translated from Atomnaya Énergiya, Vol. 71, No. 4, pp. 320–325, October, 1991.     

Release of fission products from the reactor fuel of the bilibinsk nuclear power plant under conditions which simulate a severe accident

Power Physics Institute (FÉI). Translated from Atomnaya Énergiya, Vol. 74, No. 5, pp. 416–421, May, 1993.     

Safety of VVÉR reactors

Conclusions Experience in the operation of NPP with VVÉR reactors from 1964 confirms that the steps taken to ensure their safety were in the right direction. The escape of radioactivity from NPP and the radiation doses in their rooms are significantly below admissible values. The operation of NPP with VVÉR reactors has not affected the radioactivity levels measured in their vicinity. The only cases of leaks in the primary loop were compensated by the reserve water supply at a pressure close to nominal. The extensive measures to ensure the safety of NPP with VVÉR reactors under construction and those being designed at the present time are in line with their increasing use in the USSR power system.Translated from Atomnaya Énergiya, Vol. 43, No. 6, pp. 449–457, December, 1977.     

Improving fuel utilization in the VVÉR-440

I. V. Kurchatov Institute of Atomic Energy (IAÉ). Translated from Atomnaya Énergiya, Vol. 72, No. 1, pp. 104–106, January, 1992.     

Monitoring core power distribution

All-Union Scientific Research Institute for Atomic Power Plants (VNIIAÉS). Translated from Atomnaya Énergiya, Vol. 71, No. 4, pp. 293–297, October, 1991.     

Analysis of errors in measuring coolant velocity by a thermal correlation method

Power Physics Institute (FÉI). Translated from Atomnaya Énergiya, Vol. 71, No. 2, pp. 175–178, August, 1991.     

Laws of the transformation of the photon angle and energy spectra at the soil surface during vertical migration137Cs and134Cs

IBRAÉ Russian Academy of Sciences. Institute of Radiation Physicochemical Problems, Academy of Sciences of the Republic of Belarus. Translated from Atomnaya Énergiya, Vol. 74, No. 3, pp. 230–237, March, 1993.     

Effect of irradiation on the plastic anisotropy of oriented polycrystals

IBRAÉ of the Russian Academy of Sciences. Moscow Engineering Physics Institute (MIFI). Translated from Atomnaya Énergiya, Vol. 73, No. 2, pp. 161-164, August, 1992.     

Computational Analysis of the initial stage of the accident at the Chernobyl' atomic power plant

VNIIAÉS. I. V. Kurchatov Institute of Atomic Energy. Institute of Nuclear Physics of the Academy of Sciences of the Ukrainian SSR. Translated from Atomnaya Énergiya, Vol. 71, No. 4, 275–287, October, 1991.     

Effect of235U fission on the propagation velocity of the neutron fission wave

Institute of High-Energy Physics, Academy of Sciences of the Kazakh SSR (IFVÉ AN KazSSR). Translated from Atomnaya Énergiya, Vol. 71, No. 4, pp. 309–311, October, 1991.     

Testing of experimental fuel elements for VVÉR-1000 reactors in MR to high fuel burnup

Conclusions The results of testing in a multipurpose reactor and post-irradiation examinations indicate satisfactory performance of the fuel element for the VVÉR-1000, which is designed for a 3-year run. In addition to the computational data, the experimental data were used to substantiate the performance of fuel elements when fuel burnup is increased and atomic power plants are switched from the VVÉR-1000 to a 3-year cycle (with an average burnup of 40 MW-day/kg).I. V. Kurchatov Institute of Atomic Energy. Translated from Atomnaya Énergiya, Vol. 72, No. 2, pp. 116–120. February, 1992.     

Pilot studies of an extraction process for reprocessing of spent fuel from fast reactors: Hardware and process details of extractor selection

FÉI. NIKIMT Scientific Production Association. VNIPIET Scientific Production Association. A. A. Bochvar VNIINM. Translated from Atomnaya Énergiya, Vol. 72, No. 5, pp. 481–491, May, 1992.     

TÉS-3 compact atomic power station

Conclusions The construction and operation of the TÉS-3 plant have shown that the experiment of producing a large-unit mobile power station with a water-moderated water-cooled reactor was entirely successful. The prolonged operation of TÉS-3 confirmed the reliability, satisfactory controllability and convenient servicing of this type of power station.At the same time, the operation of TÉS-3 has shown that further improvements are possible, in particular, a greater degree of automation, an increase in the run duration to two or three years, a switch to natural coolant circulation in reactor cooling, etc.We should also mention the satisfactory agreement between the theoretical basic parameters of the power station and those actually obtained, which was largely due to the many experiments performed at the design stage.Translated from Atomnaya Énergiya, Vol. 17, No. 12, pp. 448–452, December, 1964.Report No. 310, presented by the USSR at the Third International Conference on the Peaceful Uses of Atomic Energy, Geneva, 1964.Deceased.     

Controlling the transition of an htgr into equilibrium

Institute of Atomic and Thermal Energy (IATÉ). Center for Nuclear Studies, Jülich, Netherlands. Translated from Atomnaya Énergiya, Vol. 72, No. 3, pp. 279–282, March, 1992.