SUMMARY

Nuclear microreactors are an attractive technological concept that combine the advantages of lower capital costs and modularity to deliver reliable power generation for niche applications and remote communities that are otherwise not well served by conventional power utilities. Heat pipe microreactors use no/few moving parts and can operate at much higher temperatures than conventional light water reactors, which has advantages for remote operation and improved thermal efficiency. However, due to their physically small size, nuclear microreactors suffer from high neutron leakage, lowering their fuel utilization and increasing fuel cycle costs. This thesis investigates design tradeoffs to improve the fuel utilization and discharge burnup of a heat pipe monoblock microreactor fuel cycle, while retaining the advantages of microreactor concepts in economics and remote utility. Reactivity control is achieved through the use of loaded burnable absorbers, fuel coatings, and control surfaces. Heat pipe operating limits are evaluated and the implications of thermal limits discussed.