By completing this test, all tests that needed to be confirmed for the purpose of the pre-service inspection have been completed. Operational performance was verified at the maximum discharging capacity designed, and a given number of batches can be operated while the glass temperature, gas phase temperature, and the temperature of the furnace bottom is within the target range. Implementation of measures such as controlling the occurrence and deposition of foreign material at the discharge nozzle. After the measures were implemented, it was confirmed that the flowing properties had recovered.
Hence the process moved on to pre-confirmation tests. Since external power supply was lost, events such as having to use the emergency generator etc.
The areas outside the power station were not affected and there was no leakage of radioactive substances from JNFL. Dripping of radioactive liquid waste from the flange part closing the high level liquid waste supply pipe was detected.
When the monitoring was stepped up by means of ITV camera, once again dripping of high level liquid waste occurred. It was confirmed that there was a pool of water in the tray leakage had recurred set up under the flange closing the pipes transporting high level liquid waste. The movement of the stirring rod had become slow.
fensterstudio.ru/components/pumedejij/cuc-espia-whatsapp.php When the inside of the melter was checked with a camera it was found that the stirring rod was bent. When the inside of the melter was checked with a camera, it was confirmed that some of the glass melter ceiling bricks had been damaged. When the causes and the measures taken were summarized and investigated, it was confirmed that there was no problem in terms of safety of operation in the future. The operational performance verification test of the glass melter had been started.
However, as sufficient discharge flow of glass could not be confirmed, the operation was stopped. Currently, the Reprocessing Plant is in the stage of "Final Commissioning-Test" and planned to complete its construction in the first half of FY Our Business. Reprocessing flow. First half of FY Scheduled completion.
There are two types of micronuclear reactor power source Rowe, : 1 isotope generator, which converts decay heat into electric energy; 2 nuclear reactor power source, which converts fission heat into electricity energy. Comprehensively considering the reactor mass and volume, criticality safety, reliability, and maneuverability, heat pipe cooled fast reactor power source featured with compact structure, less movable parts, high reliability, and low noise level could be widely used in the power system of unmanned underwater vehicle in the future Rowe, Heat pipe cooled reactor has already been widely researched.
Various micro heat pipe cooled reactor power sources for space missions have been designed in the United States. Potassium or sodium heat pipe are adopted for cooling. MSR Bushman et al. SAFE Poston et al. China institute of atomic energy has put forward a variety of heat pipe reactor designs for space missions, such as the mars surface power plant, and the lunar surface power plant HPCMR Chengzhi et al. Based on a literature review, a micro heat pipe cooled nuclear reactor power source applied for underwater vehicle featured with 2.
Lithium heat pipe cooled core, six control drums, tungsten, and an open water loop shield are adopted in this power source. Monte Carlo program and ORIGEN are used to preliminarily calculate design parameters and analyze the criticality safety and burnup characteristics of the design scheme, etc.
The nuclear reactor power source consists of the following parts: core, control drums, shield, heat pipes, and thermoelectric generator.
The working principle is shown in Figure 1. In reactor core, fission fuels generate heat in chain reaction controlled by control drums. The heat is transferred by heat pipes and is converted into electrical power by thermoelectric generator. Waste heat is taken away by water. The core structure is shown in Figure 2 , and the key parameters of reactor core are shown in Table 1.
The core is made up of 90 fuel pins, 37 heat pipes, BeO reflector, and 6 control drums. Figure 3 shows the design parameters of fuels and heat pipes. The matrix is put in a barrel on whose inner surface is a coating of Gd 2 O 3 burnable poison. The barrel is surrounded by a BeO reflector and 6 control drums with B 4 C. Reactor core is stored in a cylinder Mo—14Re alloy barrel. Tungsten and an open water loop are used as shields in the power source system.
Thermoelectric generator is used to convert heat conducted from heat pipes into electricity of kWe. Monte Carlo program has a significant advantage of simulating geometries without much approximation.
The choice of 15 TW in the article is to test scalability limits. Nucl Technol 1 — Google Scholar. Alternative energy certainly will be the future of energy generation. Used fuel can be recycled indefinitely, with on-site reprocessing and associated facilities. Why can't they operate anywhere without subsidies?
Effective multiplication factor k eff is one of the most important parameters in criticality calculation using MCNP. It is defined as the following equation Team, :.
These three estimates are combined using observed statistical correlations to provide the final estimate of k eff and SD Urbatsch et al. As Figure 4 shows, a model is set up to simulate the core neutronics characteristics. The active zone is axially divided into 17 layers and cells per layer. The importance of all the particles, neutron and photon, in all cells is defined to be equal to 1. The calculation requires an ACE format nuclear database.
According to preliminary thermal analysis, the fuel temperature is assumed 2, K, temperature of the heat pipes and matrix is 1, K, and temperature of the control drums and reflector is K for neutronics analysis. MCNP5 is used to calculate the power distribution of the core. It can be seen from the Figure 7 that the power reaches a maximum value at the center of the active zone and decreases from the center to the periphery where control drums and reflector locate.
Reflector has influence on radial power distribution, due to the neutron reflection effect. The radial power peak factor obtained is 1.
DEVELOPMENT OF IMPROVED BURNABLE POISONS FOR. COMMERCIAL NUCLEAR POWER REACTORS. Report on Phase 1 of NERI Project Number . Download Citation on ResearchGate | Development of Improved Burnable Poisons for Commercial Nuclear Power Reactors | Burnable poisons are used in all.
Axial normalized power density of the hottest, the average, and the coldest channel are shown in Figure 6. The axial power peak factor is 1. The power peak factor of the core 1.
The reactivity feedback is considered an important factor for reactor safety. The impact of Doppler broadening effect and the density change due to thermal expansion are considered in the calculation. The thermal expansion coefficient of UN fuel is considered by the equation as follows:. The thermal expansion coefficient of B 4 C on six control drums is considered by the equation as follows:.
The thermal expansion coefficient of BeO reflector is considered by the equation and data given by Kozlovskii and Stankus The reactivity change with the core temperature varying from cold condition K to thermal condition 1, K is shown in Figure 8. Reactivity decreases as the temperature increases.
Reactivity is mainly caused by neutron leakage for thermal expansion of the reflector. The thermal power is defined 2. The effective multiplication factor change during the core life is shown in Figure 9. The lifetime of the heat pipe cooled reactor core is 14 years. Due to the depletion of burnable poison and fast neutron breeding effect, the effective multiplication factor increases at the beginning of life and then deceases when burnable poison run out until the end of life. As Figure 10 shows, a channel in active zone is defined as an area including a heat pipe and part of the surrounding fuels, air gaps, and matrix.
One-dimensional calculation model for each channel is shown in Figure The temperature of the active zone channels is shown in Figure The maximum temperature of fuels is 2, K. The maximum power of heat pipes is The temperature of thermocouple unit is also obtained by the same code. As shown in Figure 12 , temperature of thermocouple unit varies from to 1, K.
In this paper, a core of a heat pipe cooled reactor power source applied for underwater vehicle is designed. The core featured with 2. Six control drums with B 4 C neutron poison have the capability of controlling the reactivity and keeping the reactor safe.
The main design parameters are as follows:. This work provides a reference to the design and application of the micronuclear power source. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Bess, J.
Technical Reports no. Google Scholar.