Very High Temperature Reactors (VHTRs) and High Temperature Gas Reactors (HTGRs) are Generation IV gas reactors that promise to deliver high temperature process heat and efficient electricity for both industrial and commercial purposes. They have a high level of inherent passive safety making them a viable alternative to traditional water-cooled reactors. These helium gas-cooled reactors use graphite containing U-235 TRISO fuel particles in their core, as a moderator to slow down neutrons for fission chain reactions and for general core support. In the event of a primary circuit pipe break, the coolant gas escapes into the surrounding reactor cavity until the pressure between the reactor pressure vessel (RPV) and cavities equalize. At this point, it is possible for air to flow back into the RPV, where it can react exothermally with high temperature graphite and result in damages to the reactor components. This research investigates the spatial distributions of air and helium concentrations, and their temperature fields in simulated reactor cavities of a reactor building following a hypothetical Loss of Coolant Accident.
","abstract_html":"<h1>Abstract</h1> <p>Very High Temperature Reactors (VHTRs) and High Temperature Gas Reactors (HTGRs) are Generation IV gas reactors that promise to deliver high temperature process heat and efficient electricity for both industrial and commercial purposes. They have a high level of inherent passive safety making them a viable alternative to traditional water-cooled reactors. These helium gas-cooled reactors use graphite containing U-235 TRISO fuel particles in their core, as a moderator to slow down neutrons for fission chain reactions and for general core support. In the event of a primary circuit pipe break, the coolant gas escapes into the surrounding reactor cavity until the pressure between the reactor pressure vessel (RPV) and cavities equalize. At this point, it is possible for air to flow back into the RPV, where it can react exothermally with high temperature graphite and result in damages to the reactor components. This research investigates the spatial distributions of air and helium concentrations, and their temperature fields in simulated reactor cavities of a reactor building following a hypothetical Loss of Coolant Accident.</p>","abstract_has_math":false,"creators":["Abubakar, Abdullah"],"institution":null,"degree_name":"Master of Engineering (M.E.)","degree_level":"Thesis","degree_discipline":"Chemical Engineering","degree_department":null,"school":null,"contributors":["Masahiro Kawaji"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2022,"date_issued":"2022-01-01T08:00:00Z","date_published":"2022-01-01T08:00:00Z","updated_at":"2026-07-24T01:57:59Z","subjects":["VHTR","nuclear energy","global warming","reactor building","reactor cavities","DFLOC","DCC","LOCA","DBA","Nuclear Engineering"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://academicworks.cuny.edu/cc_etds_theses/1064","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Masahiro Kawaji"]},{"key":"dc:creator","label":"Author","values":["Abubakar, Abdullah"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2023-02-20T08:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Engineering (M.E.)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["VHTR","nuclear energy","global warming","reactor building","reactor cavities","DFLOC","DCC","LOCA","DBA","Nuclear Engineering"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://academicworks.cuny.edu/cc_etds_theses/1064"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Very High Temperature Reactors (VHTRs) and High Temperature Gas Reactors (HTGRs) are Generation IV gas reactors that promise to deliver high temperature process heat and efficient electricity for both industrial and commercial purposes. They have a high level of inherent passive safety making them a viable alternative to traditional water-cooled reactors. These helium gas-cooled reactors use graphite containing U-235 TRISO fuel particles in their core, as a moderator to slow down neutrons for fission chain reactions and for general core support. In the event of a primary circuit pipe break, the coolant gas escapes into the surrounding reactor cavity until the pressure between the reactor pressure vessel (RPV) and cavities equalize. At this point, it is possible for air to flow back into the RPV, where it can react exothermally with high temperature graphite and result in damages to the reactor components. This research investigates the spatial distributions of air and helium concentrations, and their temperature fields in simulated reactor cavities of a reactor building following a hypothetical Loss of Coolant Accident.
"]},{"key":"dc:title","label":"Title","values":["Helium-Air mixing in simulated reactor cavities of Very High Temperature Reactors"]}]}],"canonical_facts":{"dc:contributor":["Masahiro Kawaji"],"dc:creator":["Abubakar, Abdullah"],"dc:date.available":["2023-02-20T08:00:00Z"],"dc:description.abstract":["Very High Temperature Reactors (VHTRs) and High Temperature Gas Reactors (HTGRs) are Generation IV gas reactors that promise to deliver high temperature process heat and efficient electricity for both industrial and commercial purposes. They have a high level of inherent passive safety making them a viable alternative to traditional water-cooled reactors. These helium gas-cooled reactors use graphite containing U-235 TRISO fuel particles in their core, as a moderator to slow down neutrons for fission chain reactions and for general core support. In the event of a primary circuit pipe break, the coolant gas escapes into the surrounding reactor cavity until the pressure between the reactor pressure vessel (RPV) and cavities equalize. At this point, it is possible for air to flow back into the RPV, where it can react exothermally with high temperature graphite and result in damages to the reactor components. This research investigates the spatial distributions of air and helium concentrations, and their temperature fields in simulated reactor cavities of a reactor building following a hypothetical Loss of Coolant Accident.
"],"dc:identifier":["https://academicworks.cuny.edu/cc_etds_theses/1064"],"dc:subject":["VHTR","nuclear energy","global warming","reactor building","reactor cavities","DFLOC","DCC","LOCA","DBA","Nuclear Engineering"],"dc:title":["Helium-Air mixing in simulated reactor cavities of Very High Temperature Reactors"],"thesis:degree_discipline":["Chemical Engineering"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Engineering (M.E.)"]},"updated_at":"2026-07-24T01:57:59Z"}