Practice for Testing Graphite and Boronated Graphite Materials for High-Temperature Gas-Cooled Nuclear Reactor Components

2008 ◽  
Author(s):  
2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Michał Dudek ◽  
Zygmunt Kolenda ◽  
Marek Jaszczur ◽  
Wojciech Stanek

Nuclear energy is one of the possibilities ensuring energy security, environmental protection, and high energy efficiency. Among many newest solutions, special attention is paid to the medium size high-temperature gas-cooled reactors (HTGR) with wide possible applications in electric energy production and district heating systems. Actual progress can be observed in the literature and especially in new projects. The maximum outlet temperature of helium as the reactor cooling gas is about 1000 °C which results in the relatively low energy efficiency of the cycle not greater than 40–45% in comparison to 55–60% of modern conventional power plants fueled by natural gas or coal. A significant increase of energy efficiency of HTGR cycles can be achieved with the increase of helium temperature from the nuclear reactor using additional coolant heating even up to 1600 °C in heat exchanger/gas burner located before gas turbine. In this paper, new solution with additional coolant heating is presented. Thermodynamic analysis of the proposed solution with a comparison to the classical HTGR cycle will be presented showing a significant increase of energy efficiency up to about 66%.


2014 ◽  
Vol 1030-1032 ◽  
pp. 232-235
Author(s):  
Fu Juan Han ◽  
Jun Feng Li

Carbon-14 is a radionuclide, which is a by-product in the operation of various nuclear reactor facilities. it also came from the interaction of cosmic ray with nitrogen and hydrogen in the atmosphere globally. This article elaborates the source of the 14C in High-Temperature Gas-Cooled Reactor, the amount of 14C released to the environment, as well as the forms of carbon-14. Meanwhile, the author presents the environment impact of this radionuclide. This paper concluded that 14N (n, p) 14C reaction in the fuel spheres and coolant gas is major source, and CO2 is major release form. The conclusion could provide the references and suggestions for storage, disposal and release reduction of this type of waste.


Author(s):  
Zhe Dong ◽  
Xiaojin Huang ◽  
Liangju Zhang

The modular high-temperature gas-cooled nuclear reactor (MHTGR) is seen as one of the best candidates for the next generation of nuclear power plants. China began to research the MHTGR technology at the end of the 1970s, and a 10 MWth pebble-bed high temperature reactor HTR-10 has been built. On the basis of the design and operation of the HTR-10, the high temperature gas-cooled reactor pebble-bed module (HTR-PM) project is proposed. One of the main differences between the HTR-PM and HTR-10 is that the ratio of height to diameter corresponding to the core of the HTR-PM is much larger than that of the HTR-10. Therefore it is not proper to use the point kinetics based model for control system design and verification. Motivated by this, a nodal neutron kinetics model for the HTR-PM is derived, and the corresponding nodal thermal-hydraulic model is also established. This newly developed nodal model can reflect not only the total or average information but also the distribution information such as the power distribution as well. Numerical simulation results show that the static precision of the new core model is satisfactory, and the trend of the transient responses is consistent with physical rules.


2015 ◽  
Author(s):  
◽  
Lukas Michael Carter

High-temperature gas-cooled reactors (HTGRs) are one of the candidates being considered for the replacement of current nuclear reactor designs. Diffusion coefficients for fission products in HTGR graphite are required for estimation of fission product release rates from such reactors. We developed a method for analysis of fission product of fission product surrogate release rates from heated graphite samples. The graphite samples were infused with fission product surrogate material, and material which diffused from the graphite samples was transported via a carbon aerosol laden He jet system to an online inductively coupled plasma mass spectrometer for quantification of the release rate. Diffusion coefficients for cesium in IG-110 and NBG-18 grade nuclear graphites are reported.


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