scholarly journals OPTIMIZATION OF IGNITION ZONE OF ADVANCED FAST REACTOR, WORKING IN NUCLEAR BURNING WAVE MODE

2019 ◽  
pp. 80-85
Author(s):  
S. P. Fomin ◽  
A. I. Kirdin ◽  
M. S. Malovytsia ◽  
V. V. Pilipenko ◽  
N. F. Shul’ga
Keyword(s):  
Fast Reactor ◽  
Wave Mode ◽  
The Self ◽  
Smooth Transition ◽  
Fissile Material ◽  
Burning Wave ◽  
Fuel Burn ◽  
Nuclear Burning ◽  
Reactor Operating ◽  
Ignition Zone

This article deals with the problem of optimizing composition and structure of the ignition zone of the fast reactor operating in the self-sustaining mode of nuclear burning wave with the purpose of its smooth start-up and reducing fissile material amount in initial assembly. The cylindrical homogeneous reactor with the ignition zone placed in the center or near the cylinder end is considered. The analysis has been performed basing on solving the non-stationary neutron diffusion equation together with the fuel burn-up equations and the equations of nuclear kinetics for precursor nuclei of delayed neutrons, with using the radial buckling approximation. An optimized structure of the ignition zone has been proposed, which ensures a smooth transition of the reactor to the self-sustaining nuclear burning wave mode, avoiding an excessive energy release, which is observed when using a simplified scheme of ignition zone. Comparison of the startup variants with the ignition zone at the cylinder end and at its center shows the benefits of the second one.

scholarly journals Nuclear Burning Wave Concept and Theoretical Approaches for its Description

2020 ◽  
Keyword(s):  
Fast Neutron ◽  
Nuclear Fuel ◽  
Nuclear Power ◽  
Neutron Transport ◽  
Wave Mode ◽  
Nuclear Power Engineering ◽  
Power Engineering ◽  
Theoretical Approaches ◽  
Burning Wave ◽  
Nuclear Burning

After two major nuclear power plant accidents in Chernobyl (1986) and Fukushima (2011), one of the main requirements for the nuclear power engineering is the safety of the nuclear reactors in operation, as well as new nuclear power plants of the fourth generation, which are being developed now. One of such requirements is presence of the so-called “inherent safety” mechanism, which renders the uncontrolled reactor runaway impossible under any conditions, moreover, the implementation of such a mechanism should be ensured on the level of physical principles embedded in the reactor design. Another important problem of the nuclear power engineering is the need of the transition to the large-scale use of the fast-neutron breeder reactors, with which it would be possible to set up expanded reproduction of the nuclear fuel and by that means solve the problem of supplying humanity with relatively cheap energy for thousands of years. Moreover, at present an unresolved problem is the disposal of spent nuclear fuel containing radioactive nuclides with long half-lives, which presents a long-term danger to the ecology. One of the promising conceptions of the fast-neutron breeder reactor, which can, in the case of successful implementation, partially or even entirely solve the problems of the nuclear power engineering mentioned above, is the reactor that operates in the nuclear burning wave mode, which is also known as “Traveling wave reactor”, CANDLE and by some other names. This paper presents a short review of the main theoretical approaches used for description of such a physical phenomenon as slow nuclear burning (deflagration) wave in the neutron multiplication medium initially composed of the fertile material 238U or 232Th. A comparative analysis of the possibilities of different mathematical models for describing this phenomenon is performed, both for those based on the deterministic approach (i.e. solving neutron transport equations) and for models that use Monte Carlo methods. The main merits of the fast breeder reactor, working in the nuclear burning wave mode, and problems related to the practical realization of the considered concept are discussed.

Initiation and propagation of nuclear burning wave in fast reactor

2008 ◽  
Vol 50 (2-6) ◽  
pp. 163-169 ◽  
Author(s):  
S.P. Fomin ◽  
Yu.P. Mel'nik ◽  
V.V. Pilipenko ◽  
N.F. Shul'ga
Keyword(s):  
Fast Reactor ◽  
Burning Wave ◽  
Initiation And Propagation ◽  
Nuclear Burning

scholarly journals On Some Fundamental Peculiarities of the Traveling Wave Reactor

2015 ◽  
Vol 2015 ◽  
pp. 1-23 ◽  
Author(s):  
V. D. Rusov ◽  
V. A. Tarasov ◽  
I. V. Sharph ◽  
V. N. Vashchenko ◽  
E. P. Linnik ◽  
...  
Keyword(s):  
Cross Sections ◽  
Traveling Wave ◽  
Blow Up ◽  
Stability Loss ◽  
Wave Mode ◽  
Fuel Temperature ◽  
Burning Wave ◽  
Nuclear Burning ◽  
Flow Evolution ◽  
First Time

On the basis of the condition for nuclear burning wave existence in the neutron-multiplying media (U-Pu and Th-U cycles) we show the possibility of surmounting the so-called dpa-parameter problem and suggest an algorithm of the optimal nuclear burning wave mode adjustment, which is supposed to yield the wave parameters (fluence/neutron flux, width and speed of nuclear burning wave) that satisfy the dpa-condition associated with the tolerable level of the reactor materials radioactive stability, in particular that of the cladding materials. It is shown for the first time that the capture and fission cross sections of238U and239Pu increase with temperature within 1000–3000 K range, which under certain conditions may lead to a global loss of the nuclear burning wave stability. Some variants of the possible stability loss due to the so-called blow-up modes (anomalous nuclear fuel temperature and neutron flow evolution) are discussed and are found to possibly become a reason for a trivial violation of the traveling wave reactor internal safety.

Nuclear burning wave in fast reactor with mixed Th-U fuel

2011 ◽  
Vol 53 (7) ◽  
pp. 800-805 ◽  
Author(s):  
S.P. Fomin ◽  
O.S. Fomin ◽  
Yu.P. Mel’nik ◽  
V.V. Pilipenko ◽  
N.F. Shul’ga
Keyword(s):  
Fast Reactor ◽  
Burning Wave ◽  
Nuclear Burning

Influence of the radial neutron reflector efficiency on the power of fast nuclear-burning-wave reactor

2020 ◽  
Vol 148 ◽  
pp. 107699
Author(s):  
S.P. Fomin ◽  
A.I. Kirdin ◽  
M.S. Malovytsia ◽  
V.V. Pilipenko ◽  
N.F. Shul’ga
Keyword(s):  
Burning Wave ◽  
Nuclear Burning

Control of the power of a fast reactor in the self-regulation regime and reactor startup

Atomic Energy ◽  
2005 ◽  
Vol 98 (1) ◽  
pp. 15-20 ◽  
Author(s):  
V. Ya. Gol’din ◽  
Yu. V. Troshchiev
Keyword(s):  
Fast Reactor ◽  
Self Regulation ◽  
The Self

scholarly journals The mode of operation of CANDU power reactor in thorium self-sufficient fuel cycle

2008 ◽  
Vol 23 (2) ◽  
pp. 16-21
Author(s):  
Boris Bergelson ◽  
Alexander Gerasimov ◽  
Georgy Tikhomirov
Keyword(s):  
Fuel Cycle ◽  
Power Reactor ◽  
The Self ◽  
Fissile Material ◽  
Reactor Operation ◽  
Active Core ◽  
Mode Of Operation ◽  
Neutron Power ◽  
Thorium Cycle ◽  
Maximum Content

This paper presents the results of calculations for CANDU reactor operation in the thorium fuel cycle. The calculations were performed to estimate feasibility of operation of a heavy-water thermal neutron power reactor in the self-sufficient thorium cycle. The parameters of the active core and the scheme of fuel reloading were considered to be the same as for the standard operation in the uranium cycle. Two modes of operation are discussed in the paper: the mode of preliminary accumulation of 233U and the mode of operation in the self-sufficient cycle. For calculations for the mode of accumulation of 233U, it was assumed that plutonium was used as the additional fissile material to provide neutrons for 233U production. Plutonium was placed in fuel channels, while 232Th was located in target channels. The maximum content of 233U in the target channels was about 13 kg/t of ThO2. This was achieved by six year irradiation. The start of reactor operation in the self-sufficient mode requires content of 233U not less than 12 kg/t. For the mode of operation in the self-sufficient cycle, it was assumed that all the channels were loaded with the identical fuel assemblies containing ThO2 and a certain amount of 233U. It was shown that the non-uniform distribution of 233U in a fuel assembly is preferable.

Hard Spectrum STFR (Spray Type Fast Reactor) Cooled by Water at 7.5 MPa

2004 ◽  
Author(s):  
Asashi Kitamoto ◽  
Yasunori Ohoka
Keyword(s):  
Fast Reactor ◽  
Void Ratio ◽  
Cross Flow ◽  
Hot Water ◽  
Future Performance ◽  
Mox Fuel ◽  
Fuel Burn ◽  
Hard Spectrum ◽  
Two Phases ◽  
Gen Iv

New concept of fast reactor (FR), i.e. the STFR (Spray Type FR), is proposed here to perform high burn-up of UO2 fuel or MOX fuel by the use of BWR technology, and to improve the backend process of discharged fuel. STFR can be realized by some important changes of BWR system, at 7.50MPa. In case of STFR, heat produced in the core is removed by the evaporation of sprayed hot water jetted to fuel with cross flow at 7.50MPa, and two phases (liquid and vapor) of coolant at high void ratio goes down to the bottom of PV (pressure vessel). This is an improved concept of BWR, which can be regarded as a breakthrough of FBR. This concept has not been listed in GEN IV. Future performance of STFR are as follows, (1) STFR can increase the fraction of direct fission of 238U with neutron reaction of higher energy than 1MeV, (2) STFR can burn the nuclear fuel to the higher burn-up (80 to 200GWd/Mg-HM) compared with BWR fuel burn-up. (3) Higher burn-up of fuel will reduce the frequency of reprocessing, so STFR can reduce the reprocessing cost per power production. (4) STFR can reduce the remains of Pu and MA (Minor Actinides: Np, Am, Cm etc.) in discharged fuel.

Religiosity, the Practices of Religions, and the Perception of Older People Among Muslims and Buddhists in Thailand

2017 ◽  
Vol 86 (2) ◽  
pp. 131-151 ◽  
Author(s):  
Sumana Leelavanichkul ◽  
Aphichat Chamratrithirong ◽  
Aree Jampaklay ◽  
Rossarin Gray
Keyword(s):  
Older People ◽  
Social Value ◽  
The Self ◽  
Smooth Transition ◽  
Regression Analyses ◽  
Self Assessment ◽  
Positive Effects ◽  
Aging Society ◽  
Positive Attitudes ◽  
Using Data

We examined the effects of religiosity and the practices of religions among the Buddhists and Muslims aged 20 to 79 in Thailand on maintaining positive attitudes toward older people. Factor and multiple regression analyses are applied, using data from the 2011 National Survey on Conditions of Society and Culture. The measures of perception of older people are Social Value and Personal Value. Religiosity is measured by the self-assessment of religious strictness and one’s own practices according to the religious principles. Among Buddhists, the practices are measured by the frequency of praying, Takbat, Pancha Sila, and meditation. For Muslims, the practices are measured by the frequency of doing Salat, observing Saum, and giving Zakat. We found that religiosity and some practices of religions have positive effects on the perception of the value of older people. In addition, social policy for a smooth transition to an aging society should be considered alongside this religious mechanism.

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