ICONE Competition - ICONE28-POWER2020-16450: Modeling of Low-Temperature Reduction of Metal Oxide in Hydrogen Treatment System for Severe Accidents in Nuclear Power Plants

2021 ◽  
Author(s):  
Rajinder Khurmi
Keyword(s):  
Low Temperature ◽  
Metal Oxide ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Treatment System ◽  
Hydrogen Treatment ◽  
Temperature Reduction ◽  
Severe Accidents ◽  
Low Temperature Reduction

scholarly journals Smart support system for diagnosing severe accidents in nuclear power plants

2018 ◽  
Vol 50 (4) ◽  
pp. 562-569 ◽  
Author(s):  
Kwae Hwan Yoo ◽  
Ju Hyun Back ◽  
Man Gyun Na ◽  
Seop Hur ◽  
Hyeonmin Kim
Keyword(s):  
Support System ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Severe Accidents

Modeling of Low-Temperature Reduction of Metal Oxide in Hydrogen Treatment System for Severe Accidents in Nuclear Power Plants

2020 ◽  
Author(s):  
Kotaro Nakamura ◽  
Masashi Tanabe ◽  
Satoru Abe ◽  
Takashi Mawatari ◽  
Takao Nakagaki
Keyword(s):  
Water Vapor ◽  
Metal Oxide ◽  
Nuclear Power ◽  
Elevated Temperatures ◽  
Fixed Bed ◽  
Reaction Rates ◽  
Numerical Calculations ◽  
Treatment System ◽  
Fixed Bed Reactor ◽  
Hydrogen Treatment

Abstract At the Fukushima Daiichi nuclear power plant, zirconium in the fuel rod cladding reacted with water vapor at elevated temperatures due to a loss of cooling water, resulting in the production of a large amount of hydrogen. This hydrogen leaked from the reactor vessel and accumulated in the top of reactor building, eventually leading to an explosion. A hydrogen treatment system that re-oxidizes hydrogen to water vapor is one of the effective methods to prevent such an explosion. A prominent re-oxidation method is via a fixed bed reactor packed with metal oxide pellets. The advantages of this method are its relatively fast oxidation rate without external oxygen/air injection. In this study, experiments and complementary numerical calculations were performed on the hydrogen re-oxidation reaction by metal oxides. The oxidation of hydrogen by copper oxide is modeled by 5 interacting, elementary reactions consisting of 6 chemical species. Experiments were performed using two packed bed set-ups, with measurement of inlet/outlet gas composition and pre/post-analysis of solid composition used to determine constants of the individual reaction rates for numerical calculations. From these reaction constants, the temporal behavior of the outlet gas was predicted.

Background on Low Temperature Overpressure Protection System Setpoints for Pressure-Temperature Curves

2020 ◽  
Author(s):  
Jeffrey C. Poehler ◽  
Gary L. Stevens ◽  
Anees A. Udyawar ◽  
Amy Freed
Keyword(s):  
Low Temperature ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Pressure Vessels ◽  
Pressurized Water Reactors ◽  
Documentation System ◽  
Pressurized Water ◽  
System Pressure ◽  
Water Reactors

Abstract ASME Code, Section XI, Nonmandatory Appendix G (ASME-G) provides a methodology for determining pressure and temperature (P-T) limits to prevent non-ductile failure of nuclear reactor pressure vessels (RPVs). Low-Temperature Overpressure Protection (LTOP) refers to systems in nuclear power plants that are designed to prevent inadvertent challenges to the established P-T limits due to operational events such as unexpected mass or temperature additions to the reactor coolant system (RCS). These systems were generally added to commercial nuclear power plants in the 1970s and 1980s to address regulatory concerns related to LTOP events. LTOP systems typically limit the allowable system pressure to below a certain value during plant operation below the LTOP system enabling temperature. Major overpressurization of the RCS, if combined with a critical size crack, could result in a brittle failure of the RPV. Failure of the RPV could make it impossible to provide adequate coolant to the reactor core and result in a major core damage or core melt accident. This issue affected the design and operation of all pressurized water reactors (PWRs). This paper provides a description of an investigation and technical evaluation regarding LTOP setpoints that was performed to review the basis of ASME-G, Paragraph G-2215, “Allowable Pressure,” which includes provisions to address pressure and temperature limitations in the development of P-T curves that incorporate LTOP limits. First, high-level summaries of the LTOP issue and its resolution are provided. LTOP was a significant issue for pressurized water reactors (PWRs) starting in the 1970s, and there are many reports available within the U.S. Nuclear Regulatory Commission’s (NRC’s) documentation system for this topic, including Information Notices, Generic Letters, and NUREGs. Second, a particular aspect of LTOP as related to ASME-G requirements for LTOP is discussed. Lastly, a basis is provided to update Appendix G-2215 to state that LTOP setpoints are based on isothermal (steady-state) conditions. This paper was developed as part of a larger effort to document the technical bases behind ASME-G.

scholarly journals Report to The American Physical Society of the study group on radionuclide release from severe accidents at nuclear power plants

1985 ◽  
Vol 57 (3) ◽  
pp. S1-S144 ◽  
Author(s):  
Richard Wilson ◽  
Kamal J. Araj ◽  
Augustine O. Allen ◽  
Peter Auer ◽  
David G. Boulware ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
American Physical Society ◽  
Study Group ◽  
Severe Accidents ◽  
American Physical ◽  
Radionuclide Release
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