Research of Hydrogen Concentration Measurement in Containment Vessel of Nuclear Power Plant

We have studied nuclear power plant for district heating. Already some towns and villages in Hokkaido have requested small reactor for district heating. Using existing technology allows us to shorten development period and to keep a lid on development cost. We decided to develop new reactor based on “MUTSU” reactor technology because “MUTSU” had already proved its safety. And this reactor was boron free reactor. It allows plant system to reduce the chemical control system. And moderator temperature coefficient is deeply negative. It means to improve its operability and leads to dependability enhancement. We calculated burn-up calculation of erbium addition fuel. In the result, the core life became about 10 years. And we adapt the cassette type refueling during outage in order to maintain nonproliferation. In the district heating system, a double heat exchanger system enables to response to load change in season. To obtain the acceptance of public, this system has a leak prevention system of radioactive materials to public. And road heating system of low grade heat utilization from turbine condenser leads to improve the heat utilization efficiency. We carried out performance evaluation test of district heating pipeline. Then the heat loss of pipeline is estimated at about 0.440 °C/km. This result meets general condition, which is about 1 °C/km. This small plant has passive safety system. It is natural cooling of containment vessel. In case of loss of coolant accident, decay heat can remove by natural convection air cooling after 6 hours. Decay heat within 6 hours can remove by evaporative heat transfer of pool on containment vessel.

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Prediction of hydrogen concentration in nuclear power plant containment under severe accidents using cascaded fuzzy neural networks

Nuclear Engineering and Design ◽

10.1016/j.nucengdes.2016.02.015 ◽

2016 ◽

Vol 300 ◽

pp. 393-402 ◽

Cited By ~ 8

Author(s):

Geon Pil Choi ◽

Dong Yeong Kim ◽

Kwae Hwan Yoo ◽

Man Gyun Na

Keyword(s):

Neural Networks ◽

Power Plant ◽

Nuclear Power Plant ◽

Hydrogen Concentration ◽

Nuclear Power ◽

Fuzzy Neural Networks ◽

Severe Accidents ◽

Fuzzy Neural

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The buckling strength of a steel containment vessel with discontinuous stiffening rings of a nuclear power plant

Transactions of the JSME (in Japanese) ◽

10.1299/transjsme.20-00245 ◽

2020 ◽

Vol 86 (890) ◽

pp. 20-00245-20-00245

Author(s):

Kazuhiro MIURA ◽

Takashi OKAFUJI ◽

Mitsuhiro NAKAMURA ◽

Tatsuyuki HARADA ◽

Noriyuki HAKODA ◽

...

Keyword(s):

Power Plant ◽

Nuclear Power Plant ◽

Nuclear Power ◽

Buckling Strength ◽

Containment Vessel

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Fundamental Experiments on Local Hydrogen Behaviors Under Severe Accident Conditions in a Rectangular Subcompartment of Nuclear Power Plant

10th International Conference on Nuclear Engineering, Volume 4 ◽

10.1115/icone10-22637 ◽

2002 ◽

Cited By ~ 1

Author(s):

Jung-Jae Lee ◽

Un-Jang Lee ◽

Goon-Cherl Park

Keyword(s):

Power Plant ◽

Nuclear Power Plant ◽

Hydrogen Concentration ◽

Concentration Distribution ◽

Nuclear Power ◽

Experimental Results ◽

Severe Accident ◽

Severe Accidents ◽

Helium Gas ◽

Accident Conditions

During severe accidents in nuclear power plant (NPP), the limit of local hydrogen concentration is regulated to ensure the integrity of containment. In this study hydrogen mixing experiments were conducted to investigate the hydrogen concentration distribution in a subcompartment of NPP. The mixing compartment is a vertical rectangular type with the dimension of 1×1×1.5 m3. The helium gas was used as a simulant of hydrogen. The goals of this study are to understand local hydrogen mixing phenomena and to examine the effects of the wall condensing, of the existence of obstacle and of the containment spray operation on local hydrogen concentration in NPP. Experimental results showed that the hydrogen might be locally accumulated in the subcompartment and the local hydrogen concentration could instantaneously rise during the spray operation.

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A Review on Application of Technologies for Measuring Hydrogen Concentration in Containment

Volume 3: Nuclear Safety and Security; Codes, Standards, Licensing and Regulatory Issues; Computational Fluid Dynamics and Coupled Codes ◽

10.1115/icone21-15965 ◽

2013 ◽

Author(s):

Sha Luo ◽

Shaobo Wang ◽

Liang Qin ◽

Feng Pang

Keyword(s):

Power Plant ◽

Nuclear Power Plant ◽

Hydrogen Concentration ◽

Nuclear Power ◽

Nuclear Accident ◽

Severe Accident ◽

Confined Space ◽

Measuring Device ◽

Measuring Devices ◽

The World

Hydrogen concentration measuring technologies in containment can play an important role in preventing radioactive materials leakage and ensuring the safety of people and property in nuclear accident. However, as a confined space, the environmental condition in the containment during a severe accident is very complex and harsh, with high temperature, high pressure, high humidity and high-level radioactive. Thus, it is an issue worth exploring how to ensure the availability, safety and measurement accuracy of the hydrogen measuring devices in such special conditions. This article reviews the hydrogen measuring technology and related products currently used in nuclear power plant in the world. Because of the particularity of the severe accident conditions, some measuring technology and related products need further improvement and perfection. After the Fukushima nuclear accident, the technology for measuring hydrogen concentration in containment has become more compelling. The CH-15 type hydrogen concentration measuring device, which was independent developed by the 718th Research Institute, was briefly introduced in the end of this article. With deepening understanding of nuclear accident by nuclear power industry, the advanced hydrogen measuring devices will be widely used in nuclear power plant in the world, which will be helpful to improve the safety level of nuclear power plant.

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Device for Measuring Hydrogen Concentration in Containment During Severe Accident

Volume 3: Nuclear Safety and Security; Codes, Standards, Licensing and Regulatory Issues; Computational Fluid Dynamics and Coupled Codes ◽

10.1115/icone21-15970 ◽

2013 ◽

Cited By ~ 1

Author(s):

Sha Luo ◽

Shaobo Wang ◽

Liang Qin ◽

Feng Pang

Keyword(s):

Hydrogen Concentration ◽

Nuclear Power ◽

Power Plants ◽

Nuclear Power Plants ◽

Measuring Method ◽

Nuclear Safety ◽

Concentration Measurement ◽

Severe Accident ◽

Under Construction ◽

Hydrogen Concentration Measurement

The hydrogen explosion in Fukushima nuclear accident seriously challenged the safety of nuclear power plants in the world. Therefore, strengthening hydrogen concentration measurement in containment has become very important. To raise the nuclear safety level of in-service and under construction nuclear power plants in China, based on a document which was issued by the National Nuclear Safety Administration of China (NNSA, 2012), the function requirements, components, storage, and arrangement outlines of the hydrogen monitoring system after a severe accident was thoroughly analyzed in this article. Besides, two kinds of techniques for hydrogen concentration measurement in containment, respectively for direct measuring method and gas sampling measuring method, were also discussed and compared. Notably, based on the direct measuring method, the 718th Research Institute successfully developed the CH-15 type hydrogen concentration measuring device that suitable for used in severe accident. The hydrogen sensor, with independently intellectual property rights, is based on catalytic principles and installed inside the containment. It has many unique characteristics, such as wide measurement range, high measurement accuracy, and is capable of continuous measurement with multiple points. This device has simple structure and small size, with low energy consumption, so it is very suitable for being installed in the in-service and under construction nuclear power plants in China and abroad.

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