Safety Evaluation of the HTTR-IS Nuclear Hydrogen Production System

2010 ◽  
Author(s):  
Hiroyuki Sato ◽  
Hirofumi Ohashi ◽  
Yujiro Tazawa ◽  
Nariaki Sakaba ◽  
Yukio Tachibana
Keyword(s):  
Hydrogen Production ◽  
Production System ◽  
Evaluation Method ◽  
Cooling System ◽  
Safety Evaluation ◽  
Safety Analysis ◽  
Fuel Temperature ◽  
System Pressure ◽  
Production Of Hydrogen ◽  
The Government

Establishment of a safety evaluation method is one of the key issues for the nuclear hydrogen production demonstration since fundamental differences in the safety philosophy between nuclear plants and chemical plants exist. In the present study, a practical safety evaluation method, which enables to design, construct and operate hydrogen production plants under conventional chemical plant standards, is proposed. An event identification for the HTTR-IS nuclear hydrogen production system is conducted in order to select abnormal events which would change the scenario and quantitative results of the evaluation items from the existing HTTR safety evaluation. In addition, a safety analysis is performed for the identified events. The results of safety analysis for the indentified five Anticipated Operational Occurrences (AOOs) and three ACciDents (ACDs) show that evaluation items such as a primary cooling system pressure, temperatures of heat transfer tubes at pressure boundary, etc., do not exceed the acceptance criteria during the scenario. In addition, the increase of peak fuel temperature is small in the most severe case, and therefore the reactor core was not damaged and cooled sufficiently. These results will contribute to the safety review from the government and demonstration of the nuclear production of hydrogen.

Safety Evaluation of the HTTR-IS Nuclear Hydrogen Production System

2010 ◽  
Vol 133 (2) ◽  
Author(s):  
Hiroyuki Sato ◽  
Hirofumi Ohashi ◽  
Yujiro Tazawa ◽  
Nariaki Sakaba ◽  
Yukio Tachibana
Keyword(s):  
Hydrogen Production ◽  
Production System ◽  
Evaluation Method ◽  
Cooling System ◽  
Safety Evaluation ◽  
Safety Analysis ◽  
Fuel Temperature ◽  
System Pressure ◽  
Production Of Hydrogen ◽  
The Government

The establishment of a safety evaluation method is one of the key issues for the nuclear hydrogen production demonstration since fundamental differences in the safety philosophy between nuclear plants and chemical plants exist. In the present study, a practical safety evaluation method, which enables to design, construct, and operate hydrogen production plants under conventional chemical plant standards, is proposed. An event identification is conducted for the HTTR-IS system, a nuclear hydrogen production system by thermochemical water splitting iodine-sulfur process (IS process) utilizing the heat from the high temperature engineering test reactor (HTTR) in order to select abnormal events, which would change the scenario and quantitative results of the evaluation items from the existing HTTR safety evaluation. In addition, a safety analysis is performed for the identified events. The results of safety analysis for the identified five anticipated operational occurrences (AOOs) and three accidents (ACDs) show that evaluating items such as a primary cooling system pressure, temperatures of heat transfer tubes at pressure boundary, etc., do not exceed the acceptance criteria during the scenario. In addition, the increase of peak fuel temperature is small in the most severe case and therefore, the reactor core was not damaged and cooled sufficiently. These results will contribute to the safety review from the government and demonstration of the nuclear production of hydrogen.

scholarly journals Analysis on Characteristic of Hydrogen Gas Dispersion and Evaluation Method of Blast Overpressure in VHTR Hydrogen Production System

2006 ◽  
Vol 5 (4) ◽  
pp. 316-324 ◽  
Author(s):  
Tomoyuki MURAKAMI ◽  
Atsuhiko TERADA ◽  
Tetsuo NISHIHARA ◽  
Yoshiyuki INAGAKI ◽  
Kazuhiko KUNITOMI
Keyword(s):  
Hydrogen Production ◽  
Production System ◽  
Evaluation Method ◽  
Hydrogen Gas ◽  
Gas Dispersion ◽  
Blast Overpressure

Development of an evaluation method for the HTTR-IS nuclear hydrogen production system

2009 ◽  
Vol 36 (7) ◽  
pp. 956-965 ◽  
Author(s):  
Hiroyuki Sato ◽  
Shinji Kubo ◽  
Nariaki Sakaba ◽  
Hirofumi Ohashi ◽  
Yukio Tachibana ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Production System ◽  
Evaluation Method

The ATWS Analysis of One Control Rod Withdrawal Out of the HTR-10GT Core

2010 ◽  
Author(s):  
Minggang Lang ◽  
Yujie Dong
Keyword(s):  
Gas Turbine ◽  
Cooling System ◽  
Negative Temperature ◽  
Reactor Power ◽  
Outlet Temperature ◽  
Fuel Temperature ◽  
Control Rod ◽  
The Core ◽  
System Pressure ◽  
Temperature Limitation

The 10MW High Temperature Gas Cooled Test Reactor (HTR-10) has been built in Institute of Nuclear and New Energy Technology (INET) and has been operating successfully since the beginning of 2003. The core outlet temperature of HTR-10 is 700°C. To verify the technology of gas-turbine direct cycle, at first INET had a plan to increase its core outlet temperature to 750°C and use a helium gas turbine instead of the steam generator (then the reactor is called HTR-10GT). Though HTR-10 has good intrinsic safety, the design basic accidents and beyond design basis accidents of HTR-10GT must be analyzed according to China’s nuclear regulations due to changed operation parameters. THERMIX code system is used to study the ATWS accident of one control rod withdrawal out of the core by a mistake. After a control rod in the side reflector was withdrawn out at a speed of 1 cm/s by a mistake, a positive reactivity was inserted and the reactor power increased and the temperature of the core increased. When the neutron flux of power measuring range exceeded 123% and the core outlet temperature was greater than 800°C, the reactor should scram. It was supposed that all the control rods in the reflectors had been blocked and the reactor could not scram. Thus the accident went on and the core temperature and the system pressure increased but the reactor shutdown at last because of its natural negative temperature reactivity feedback mechanism. The residual heat would be removed out of the core by the cavity cooling system. During the accident sequence the maximum fuel temperature was 1242.4°C. It was a little higher than 1230°C–the fuel temperature limitation of HTR-10. Now the sphere fuel used in HTR-10GT will also be used in HTR-PM and the temperature limitation raised to 1620°C, so the HTR-10GT is safe during the ATWS of one control rod withdrawal out of the core. The paper also compares the analysis result of HTR10-GT to those of HTR-10. The results shows that the HTR-10GT is still safe during the accident though its operating temperature is higher than HTR-10. The analysis will be helpful to HTR-PM because they have the same outlet temperature of the core.

The ATWS Analysis of One Control Rod Withdrawal Out of the HTR-10GT Core Under the Loss of the System Pressure

2014 ◽  
Author(s):  
Minggang Lang
Keyword(s):  
Gas Turbine ◽  
Cooling System ◽  
Negative Temperature ◽  
Reactor Power ◽  
Outlet Temperature ◽  
Fuel Temperature ◽  
Control Rod ◽  
The Core ◽  
Design Basis ◽  
System Pressure

The 10MW High Temperature Gas Cooled Test Reactor (HTR-10) has been built in Institute of Nuclear and New Energy Technology (INET) and has been operating successfully since the beginning of 2003. The core outlet temperature of HTR-10 is 700°C. To verify the technology of gas-turbine direct cycle, at first INET had a plan to increase its core outlet temperature to 750°C and to use a helium gas turbine instead of the steam generator (then the reactor is called HTR-10GT). Though HTR-10 has good intrinsic safety, the design basis accidents and beyond design basis accidents of HTR10-GT must be analyzed according to China’s nuclear regulations due to changed operation parameters. THERMIX code system is used to study the ATWS accident of one control rod withdrawal out of the core by a mistake under the loss of the system pressure. After a control rod in the side reflector was withdrawn out at a speed of 1 cm/s by a mistake, a positive reactivity was inserted. At the same time, the system pressure was supposed to lose by some reason. Thus the reactor power increased and the temperature of the core increased. And the protection system warns with two scram signal: too high of the negative varying rate of the system pressure and too high of the reactor power, which should induce the reactor to scram. It was supposed that all the control rods in the reflectors had been blocked and the reactor could not scram. Thus the accident went on and the core temperature and the system pressure continued to increase but the reactor shutdown at last because of its natural negative temperature reactivity feedback mechanism. The residual heat would be removed out of the core by the cavity cooling system. During the accident sequence the maximum fuel temperature was 1203.4°C. It was a little bit lower than 1230°C — the fuel temperature limitation of HTR-10 and there is no release of any radioactivity. So the HTR-10GT is safe during the ATWS of one control rod withdrawal out of the core. The paper also compares the analysis result of HTR10-GT to those of HTR-10. The results shows that the HTR-10GT is still safe during the accident though its operating temperature is higher than HTR-10.

An Evaluation Method for Suppression of Fluctuations in Renewable Energy Output and its Application to Hydrogen Production System

2019 ◽  
Vol 139 (12) ◽  
pp. 737-745
Author(s):  
Tatsuya Oyama ◽  
Hisashi Kato ◽  
Hiroshi Matsumoto ◽  
Yoichi Mashima ◽  
Hideo Hosogoe
Keyword(s):  
Renewable Energy ◽  
Hydrogen Production ◽  
Production System ◽  
Evaluation Method ◽  
Energy Output

HFE Safety Evaluation in Angra-1 NPP for the Preparation and Inclusion of a Chapter 18 in the Plant Final Safety Analysis Report

2014 ◽  
Author(s):  
Pedro Trueba Alonso ◽  
Juan Carlos Valdivia ◽  
Luís Fernández Illobre ◽  
Mark Hulsmans
Keyword(s):  
Nuclear Power ◽  
Action Plan ◽  
Safety Evaluation ◽  
Safety Analysis ◽  
Nuclear Safety ◽  
Human Factors Engineering ◽  
The European Union ◽  
Commercial Operation ◽  
The Government ◽  
Set Up

Angra-1 Nuclear Power Station (Westinghouse PWR-600 MW, 2 loops) started commercial operation in 1985, being property of Eletronuclear, subsidiary of Eletrobras in Brazil. Angra-1 has been preparing the necessary measures to renew the operating license and to apply for a lifetime extension up to 60 years. Among the many activities to perform, there are some related to fulfilling the requirements of the Brazilian regulator, the CNEN. These include requirements related to Human Factors Engineering (HFE) that included the preparation of a Chapter 18 of HFE, to become part of the plant’s Final Safety Analysis Report (FSAR). In the framework of the Instrument for Nuclear Safety Cooperation (INSC), created and funded by the European Union (EU) to enhance nuclear safety world-wide, cooperation activities between the EU and the Government of Brazil were set up in 2009. One of the INSC projects funded was to support the Brazilian nuclear operator of Angra-1 in the field of HFE. In 2010, the implementation of the project was awarded to a consortium lead by Tecnatom for performing a HFE Safety Evaluation to the plant and to provide support for preparing this Chapter 18. For this Project a specific methodology was developed for the execution of the Safety Evaluation. The methodology has been developed for evaluating — from the HFE viewpoint — a plant in operation, from the beginning of commercial operation until nowadays, including the design modifications performed to date. The obtained results have been used for developing the aforementioned Chapter 18. The main results of the Project Execution have been: 1. The developed methodology has made it possible to perform a comprehensive HFE evaluation of Angra-1, including the analysis of Post-TMI requirements, the design included in the current FSAR, the existing Angra-1 procedures and the verification of the current Main Control Room. 2. Technical support has been provided to Angra-1 for the preparation of Chapter 18 of the FSAR, following the structure of NUREG-0711, and using the results of the HFE Safety Evaluation. 3. An Action Plan has been developed for identifying and addressing in the future all those deficiencies found during the HFE Safety Evaluation, as well as those activities that are the consequence of the new FSAR Chapter 18.

Demonstration of Nuclear Hydrogen Production Utilizing the Japan’s HTTR: Control Scheme Evaluation of the HTTR-IS Nuclear Hydrogen Production System

2008 ◽  
Author(s):  
Hiroyuki Sato ◽  
Nariaki Sakaba ◽  
Naoki Sano ◽  
Hirofumi Ohashi ◽  
Yukio Tachibana ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Production System ◽  
Gas Flow ◽  
Nuclear Reactor ◽  
Cooling System ◽  
Reactor Operation ◽  
Control Scheme ◽  
Diagnosis Method ◽  
Scheme Evaluation ◽  
The Impact

One of the key technology requirements to achieve the nuclear hydrogen demonstration is the establishment of control scheme which harmonizes the reactor operation with chemical plant operation. This study focused on developing the control scheme to be considered in the HTTR-IS nuclear hydrogen production system, which are in case of (a) abnormal shut-down and (b) restart-up of the IS process. The key parameters and equipments have been determined and the control operations are simulated. The simulation results show that the impact of abnormal events initiated in the IS process on the reactor operation can be effectively minimized by the rapid initiation of diverter valves using model-based fault diagnosis method. Furthermore, the thermal shock to components in the IS process can be prevented in case of restart-up operation of the IS process by controlling the helium gas flow-rate of primary and secondary cooling system. It is confirmed by the analysis that the control scheme developed enable to maintain the reactor operation normally under all conditions and supply heat from nuclear reactor to the IS process hydrogen production system flexibly.

Safety analysis of leakage in a nuclear hydrogen production system

2021 ◽  
Author(s):  
Qunxiang Gao ◽  
Laijun Wang ◽  
Wei Peng ◽  
Ping Zhang ◽  
Songzhe Chen
Keyword(s):  
Hydrogen Production ◽  
Production System ◽  
Safety Analysis
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