Electromagnetic Self-Locking Device for Air Cylinders in Spent Fuel Storage System of Pebble-Bed High Temperature Gas-Cooled Reactor

2013 ◽  
Author(s):  
Bin Wu ◽  
Jinhua Wang ◽  
Yue Li ◽  
Jiguo Liu
Keyword(s):  
High Temperature ◽  
Temperature Rise ◽  
Storage System ◽  
Compressed Air ◽  
Maximum Temperature ◽  
Spent Fuel ◽  
Pebble Bed ◽  
Spent Fuel Storage ◽  
Fuel Storage ◽  
High Temperature Gas

In the spent fuel storage system of pebble-bed high temperature gas-cooled reactor, several air cylinders would be employed in complex machines, such as the spent fuel charging apparatus and the spent fuel canister crane. The cylinders were designed to actuate movements smoothly in radioactive environment. In order to lock them in safe position when the compressed air source is offline by accident, an electromagnetic self-locking device was designed. When power-off, the compressive spring would push out the lock plunger to enable self-lock. When power-on, the lock plunger would be withdrawn by the magnetic force of the coil to unlock the cylinder. In order to optimize the design more efficiently, numerical simulation was performed to optimize geometry parameters of the structure surrounding the working air gap so as to improve the performance of the device. A prototype was then fabricated. Combining the simulation results with experimental test, the actuating force characteristics of the device in locking and unlocking process was analyzed. The temperature rise when the device stays unlocked with power supply was also calculated and validated. The results showed that this electromagnetic self-locking device could realize the locking and unlocking functions effectively, and the maximum temperature rise also conforms the required limit. The as-fabricated device would help guarantee the fail-safe feature of the air cylinders of complex machines in compressed air outage.

Design of the Spent Fuel Storage Well of HTR-PM

2016 ◽  
Author(s):  
Jinhua Wang ◽  
Bing Wang ◽  
Bin Wu ◽  
Yue Li
Keyword(s):  
High Temperature ◽  
Storage System ◽  
Inherent Safety ◽  
Storage Facility ◽  
Spent Fuel ◽  
Hot Air ◽  
Spent Fuel Storage ◽  
Fuel Storage ◽  
Water Reactors ◽  
Residual Heat

There are more than 400 reactors in operation to generate electricity in the world, most of them are pressurized water reactors and boiling water reactors, which generate great amount of spent fuel every year. The residual heat power of the spent fuel just discharged from the reactor core is high, it is required to store the spent fuel in the spent fuel storage pool at the first 5 years after discharged from the reactor, and then the spent fuel could be moved to the interim storage facility for long term storage, or be moved to the factory for final treatment. In the accident of the Fukushima in 2011, the spent fuel pool ruptured, which led to the loss of coolant accident, it was very danger to the spent fuel assemblies stored in the pool. On the other hand, the spent fuel stored in the dry storage facility was safe in the whole process of earthquake and tsunami, which proved inherent safety of the spent fuel dry storage facility. In china, the High Temperature gas cooled Reactor (HTR) is developing for a long time in support of the government. At the first stage, HTR-10 with 10MW thermal power was designed and constructed in the Institute of Nuclear Energy Technology (INET) of Tsinghua University, and then the High Temperature Reactor-Pebble bed Modules (HTR-PM) is designed to meet the commercial application, which is in constructing process in Shandong Province. HTR has some features of the generation four nuclear power plant, including inherent safety, avoiding nuclear proliferation, could generate high temperature industrial heat, and so on. Spherical fuel elements would be used as fuel in HTR-PM, there are many coating fuel particles separated in the fuel element. As the fuel is different for the HTR and the PWR, the fuel element would be discharged into the appropriate spent fuel canister, and the canister would be stored in the appropriate interim storage facility. As the residual power density is very low for the spent fuel of HTR, the spent fuel canister could be cooled with air ventilation without water cooling process. The advantage of air cooling mode is that it is no need to consider the residual heat removal depravation due to loss of coolant accident, so as to increase the inherent safety of the spent fuel storage system. This paper introduced the design, arrangement and safety characteristics of the spent fuel storage well of HTR-PM. The spent fuel storage wells have enough capacity to hold the total spent fuel canisters for the HTR-PM. The spent fuel storage facility includes several storage wells, cold intake cabin, hot air discharge cabin, heat shield cylinders, well lids and so on. The cold intake cabin links the inlets of all the wells, which would be used to import cold air to every well. The hot air discharge cabin links the outlets of all the wells, which would be used to gather heated air discharged from every well, the heated air would be discharged to the atmosphere through the ventilating pipe at the top of the hot air cabin. The design of the spent fuel storage well and the ventilating pipe could discharge the residual heat of the spent fuel canisters in the storage wells, which could ensure the operating safety of the spent fuel storage system.

Filtration Technology Research of Graphite Dust Produced in Spent Fuel Transportation Process in HTR-PM

2018 ◽  
Author(s):  
Jinhua Wang ◽  
Bing Wang ◽  
Bin Wu ◽  
Yue Li ◽  
Haitao Wang
Keyword(s):  
High Temperature ◽  
Fuel Element ◽  
Nuclear Power ◽  
Storage System ◽  
Spent Fuel ◽  
Graphite Matrix ◽  
Fuel Storage ◽  
Fuel Elements ◽  
And Storage ◽  
High Temperature Gas

With the continuous development of the nuclear power technology in the world, all countries in the world are becoming more and more interested in the inherent safety of nuclear power technology, while the research and development of the spherical bed type high temperature gas cooled reactor nuclear power technology in China has formally catered to this demand. As a major national science and technology project, since the construction of the high temperature gas cooled reactor demonstration project (HTR-PM) since 2012, the civil construction of the nuclear island has been basically completed, the installation of equipment has been carried out orderly, and many process systems have entered debugging and operation stage gradually. As an important auxiliary process system, fuel handling and storage system for online refueling of the pebble bed high temperature gas cooled reactor, plays an important role in relation to the stable operation of the reactor. The main functions of the fuel handling and storage system are loading the fresh fuel elements and unloading the spent fuel elements which has reached its target burnup continuously for reactor operation, the spent fuel elements would be discharged into the spent fuel canister firstly, when the spent fuel storage canister is full of spent fuel, the canister would be sealed through welding method, and then the spent fuel canister would be transferred and stored in the spent fuel storage silo with the ground crane system. The fuel element of the pebble bed high temperature gas cooled reactor is spherical fuel element with graphite matrix, the fuel elements will have friction and collision with the inner wall of the pipeline in transporting process, which will produce graphite dust, the graphite dust should be removed continuously though filtration method, so as not to affect the fuel elements transportation in pipeline. This article focus on the production mechanism and filtering method of the graphite dust in graphite matrix fuel element transporting process in pipeline, to study the graphite dust removal technology, and then we could provide theoretical guidance for the design and operation of the key system and equipment for HTR-PM.

Retrieving Fuel Elements by Pneumatic Suction in Pebble-Bed High Temperature Gas-Cooled Reactor

2014 ◽  
Author(s):  
Bin Wu ◽  
Jin-hua Wang ◽  
Yue Li ◽  
Bing Wang ◽  
Ji-guo Liu
Keyword(s):  
High Temperature ◽  
Negative Pressure ◽  
Impact Damage ◽  
Storage System ◽  
Spent Fuel ◽  
Suction System ◽  
Fuel Storage ◽  
Pressure Suction ◽  
Fuel Elements ◽  
High Temperature Gas

Spent fuel storage system of pebble-bed high temperature gas-cooled reactor needs to retrieve fuel elements and spent fuel elements from storage tank during fuel reloading condition and some other special status. This function is to be achieved by the negative pressure suction system. Research in depth is needed towards the negative pressure suction system design and experiment in order to reliably supply the system with enough suction capability and meanwhile prevent the fuel element from over-speed impact damage. A comprehensive experimental facility of negative pressure suction was built to investigate and verify the designed system. The facility mainly comprises a fuel canister, a suction tube, a tube feeder, a gas isolator, a Roots blower and pipelines. The negative pressure suction force was provided by the Roots blower and drove the fuel elements out of the canister through the tube. The Roots blower was driven by a frequency converter so that the suction flow rate could be adjusted as wanted. The dynamics model of spherical element in the tube was established. The pressure drop distribution of the negative pressure suction system was also calculated. Then the pressure drops and the sphere velocity were measured at different air flow rates. Based on the experimental results and calculation analysis, parameter requirements for the Roots pump were concluded. Therefore, fuel elements could be successfully retrieved without over-speed impact damage. These results provide useful experience for engineering design of negative pressure suction system in the spent fuel storage system.

High-temperature corrosion behavior of hot-pressed Al-based Gd2O3-W shielding materials used in spent fuel storage

2021 ◽  
Vol 179 ◽  
pp. 109166
Author(s):  
Shuo Cong ◽  
Yipeng Li ◽  
Guang Ran ◽  
Wei Zhou ◽  
ShiGang Dong ◽  
...  
Keyword(s):  
High Temperature ◽  
Corrosion Behavior ◽  
High Temperature Corrosion ◽  
Spent Fuel ◽  
Spent Fuel Storage ◽  
Fuel Storage ◽  
Materials Used

Thermal-fluid flow analysis and demonstration test of a spent fuel storage system

2009 ◽  
Vol 239 (3) ◽  
pp. 551-558 ◽  
Author(s):  
J.C. Lee ◽  
W.S. Choi ◽  
K.S. Bang ◽  
K.S. Seo ◽  
S.Y. Yoo
Keyword(s):  
Fluid Flow ◽  
Storage System ◽  
Flow Analysis ◽  
Spent Fuel ◽  
Spent Fuel Storage ◽  
Fuel Storage ◽  
Thermal Fluid Flow ◽  
Fluid Flow Analysis

Numerical Analysis of the Residual Heat Removal for the Spent Fuel Canister of HTR-PM in Fuel Loading Process

2014 ◽  
Author(s):  
Jinhua Wang ◽  
Bing Wang ◽  
Bin Wu
Keyword(s):  
High Temperature ◽  
Natural Ventilation ◽  
Maximum Temperature ◽  
Spent Fuel ◽  
Fuel Loading ◽  
Pebble Bed ◽  
Loading Process ◽  
Accident Conditions ◽  
Fuel Elements ◽  
Residual Heat

High Temperature Gas Cooled Reactor (HTGR) has inherent safety, and has been selected as one of the candidates for the Gen-IV nuclear energy system. In china, the project of the High Temperature Reactor Pebble bed Module (HTR-PM) is in design and construction process. Spherical fuel elements are chosen for the HTR-PM and the spent fuel elements will be stored in canister. The spent fuel canister will be delivered to wells for storage when fully loaded. The canister is covered by a steel cask for radiation shielding, and the cask is covered by a boron polyethylene sleeve to absorb neutrons from decay in fuel loading process. Normally, the residual heat is discharged by forced ventilation in fuel loading process. An auxiliary fan is set on top of the cask considering the possible mechanical failure for the operating fan. When losing normal power supply, the emergency power will be provided to the fans by the two line diesel generators respectively. In extreme conditions of mechanical failure for both fans, the residual heat could be discharged by natural ventilation. The temperature profiles of the different structures were studied in this paper with CFD method for both normal and accident conditions. The calculation results showed that, the maximum temperature of all of the structures are lower than the safety temperature limits in either normal or accident conditions; the temperature decreases rapidly with radial distance in the canister, and the maximum temperature is located at the center of the fuel pebble bed. So it is feasible to remove the residual heat of the spent fuel by natural ventilation in accident condition, and in the natural ventilation condition, the maximum temperature of the spent fuel, the canister shell, the shielding cask, and the boron polyethylene sleeve are lower than their safety temperature limits.

scholarly journals Bypass flow in small absorber sphere channels of the high-temperature gas-cooled reactor pebble-bed module

2017 ◽  
Vol 10 (3) ◽  
pp. 128-139 ◽  
Author(s):  
Ziping Liu ◽  
Zeguang Li ◽  
Jun Sun
Keyword(s):  
High Temperature ◽  
Network Model ◽  
Reactor Core ◽  
Flow Distribution ◽  
Maximum Temperature ◽  
Bypass Flow ◽  
Pebble Bed ◽  
Flow Network ◽  
Control Rod ◽  
High Temperature Gas

In the high-temperature gas-cooled reactor pebble-bed module, the helium bypass flow among graphite blocks cannot be ignored due to its effect on the temperature distribution as well as the maximum temperature in the reactor core. Bypass flow was previously analyzed in the discharging tube, in vertical gaps between graphite reflectors, and in control rod channels. The focus of this study is on the bypass flow that connects the small absorber sphere channels. Different from bypass flow connecting the control rod channels, there was no evident inlet or outlet flow paths into or out of the small absorber sphere channels at the top or bottom of the reactor core. Therefore, the bypass flow connecting the pebble bed with the small absorber sphere channels was mainly caused by the horizontal gaps, in which those gaps would also be irregular due to installation, thermal expansion, or irradiation of the graphite reflectors. After clarifying the resistant coefficients of those gaps by computational fluid dynamic tools, the bypass flow distribution was calculated by the flow network model including the flow in the reactor core, small absorber sphere channels, as well as horizontal gaps. Cases with various size combinations of gaps were adopted into the flow network model to test the sensitivity of bypass flow distribution to those parameters. Finally, the bypass flow in the small absorber sphere channels was concluded to be not significant in the reactor core.

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