{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/129324"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/129324","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"LEU+ to HALEU nuclear fuel cycle transitions and dynamic reactor models","abstract":"Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-19 without embargo terms","abstract_html":"Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-19 without embargo terms","abstract_has_math":false,"creators":["Ryan, Nathan Sean"],"institution":"University of Illinois Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Nuclear, Plasma, Radiolgc Engr","degree_department":null,"school":null,"contributors":["Munk, Madicken","Huff, Kathryn D.","Uddin, Rizwan"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-05-07","date_published":"2025-05-07","updated_at":"2026-07-22T22:25:04Z","subjects":["Cyclus","Triso","Haleu","Leu+","Leu Plus","Serpent","Nuclear Fuel Cycle","Memory Efficiency","Dynamic Power","Fuel Trading","Reactor Deployment","Advanced Reactors"],"languages":["en","eng"],"rights":["© 2025 by Nathan Sean Ryan. All rights reserved."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/129324","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Munk, Madicken","Huff, Kathryn D.","Uddin, Rizwan"]},{"key":"dc:creator","label":"Author","values":["Ryan, Nathan Sean"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2025-05-07","2025-05"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Nuclear, Plasma, Radiolgc Engr"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Cyclus","Triso","Haleu","Leu+","Leu Plus","Serpent","Nuclear Fuel Cycle","Memory Efficiency","Dynamic Power","Fuel Trading","Reactor Deployment","Advanced Reactors"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en","eng"]},{"key":"dc:rights","label":"Dc Rights","values":["© 2025 by Nathan Sean Ryan. All rights reserved."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/129324"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-19 without embargo terms","The student, Nathan Ryan, accepted the attached license on 2025-05-05 at 13:12.","The student, Nathan Ryan, submitted this Thesis for approval on 2025-05-05 at 13:50.","This Thesis was approved for publication on 2025-05-07 at 14:47.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22210 on 2025-10-19 at 18:12:45","Understanding the nuclear fuel cycle is crucial when designing sustainable and efficient nuclear energy systems. This thesis studies timely transition scenarios for fleets of Micro Modular Reactors (MMRs), X-Energy Xe-100s (Xe-100s), and AP1000s where low-enriched uranium plus (LEU+) fuel delays the demand for high-assay low-enriched uranium (HALEU) for the TRi-structural ISOtropic (TRISO) fueled reactors through a greedy, random, and initially random then greedy deployment scheme to meet energy demand growths from the U.S. Department of Energy (DOE) and U.S. Energy Information Administration (EIA). Using the open-source code Cyclus to model fuel cycles and the Monte Carlo code Serpent to perform neutronics calculations for the Xe-100 and USNC MMR, the results show that the reactor deployment scheme impacts the separative work units (SWU) required to meet energy demand. The greedy scheme, which prefers the highest capacity reactors, leads to the most significant increase in SWU for AP1000 low-enriched uranium (LEU), while the random and initially random then greedy schemes result in more consistent increases across fuel types. By evaluating the masses of fresh and used fuel, SWU, the number of reactors, and how well each simulation meets the projected energy demand, this thesis provides a comprehensive understanding of the impact of reactor deployment schemes on the nuclear fuel cycle. Additionally, this thesis examines the computational complexity of reactor fuel trading and removes assumptions about reactor power. The Trading On-Demand (TOD) reactor reduces the number of instructions in a simulation by trading fuel only when needed, while the Dynamic Power Reactor (DPR) allows for flexible power output to mirror historical or projected capacity factors. The results show that improving reactor models and simulating fuel cycle transitions leads to more efficient reactor deployment and fuel cycle design."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["LEU+ to HALEU nuclear fuel cycle transitions and dynamic reactor models"]}]}],"canonical_facts":{"dc:contributor":["Munk, Madicken","Huff, Kathryn D.","Uddin, Rizwan"],"dc:creator":["Ryan, Nathan Sean"],"dc:date":["2025-05-07","2025-05"],"dc:description":["Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-19 without embargo terms","The student, Nathan Ryan, accepted the attached license on 2025-05-05 at 13:12.","The student, Nathan Ryan, submitted this Thesis for approval on 2025-05-05 at 13:50.","This Thesis was approved for publication on 2025-05-07 at 14:47.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22210 on 2025-10-19 at 18:12:45","Understanding the nuclear fuel cycle is crucial when designing sustainable and efficient nuclear energy systems. This thesis studies timely transition scenarios for fleets of Micro Modular Reactors (MMRs), X-Energy Xe-100s (Xe-100s), and AP1000s where low-enriched uranium plus (LEU+) fuel delays the demand for high-assay low-enriched uranium (HALEU) for the TRi-structural ISOtropic (TRISO) fueled reactors through a greedy, random, and initially random then greedy deployment scheme to meet energy demand growths from the U.S. Department of Energy (DOE) and U.S. Energy Information Administration (EIA). Using the open-source code Cyclus to model fuel cycles and the Monte Carlo code Serpent to perform neutronics calculations for the Xe-100 and USNC MMR, the results show that the reactor deployment scheme impacts the separative work units (SWU) required to meet energy demand. The greedy scheme, which prefers the highest capacity reactors, leads to the most significant increase in SWU for AP1000 low-enriched uranium (LEU), while the random and initially random then greedy schemes result in more consistent increases across fuel types. By evaluating the masses of fresh and used fuel, SWU, the number of reactors, and how well each simulation meets the projected energy demand, this thesis provides a comprehensive understanding of the impact of reactor deployment schemes on the nuclear fuel cycle. Additionally, this thesis examines the computational complexity of reactor fuel trading and removes assumptions about reactor power. The Trading On-Demand (TOD) reactor reduces the number of instructions in a simulation by trading fuel only when needed, while the Dynamic Power Reactor (DPR) allows for flexible power output to mirror historical or projected capacity factors. The results show that improving reactor models and simulating fuel cycle transitions leads to more efficient reactor deployment and fuel cycle design."],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/129324"],"dc:language":["en","eng"],"dc:rights":["© 2025 by Nathan Sean Ryan. All rights reserved."],"dc:subject":["Cyclus","Triso","Haleu","Leu+","Leu Plus","Serpent","Nuclear Fuel Cycle","Memory Efficiency","Dynamic Power","Fuel Trading","Reactor Deployment","Advanced Reactors"],"dc:title":["LEU+ to HALEU nuclear fuel cycle transitions and dynamic reactor models"],"dc:type":["text"],"thesis:degree_discipline":["Nuclear, Plasma, Radiolgc Engr"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:04Z"}