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Marc Andrew Gibson

Publications and source records attributed to Marc Andrew Gibson.

Results of the KRUSTY Nuclear System Test

The Kilowatt Reactor Using Stirling TechnologY (KRUSTY) was a prototypic nuclear-powered test of a 5-kW(thermal) Kilopower space reactor. This paper presents results from the KRUSTY nuclear system test, which operated the power system at various temperatures and power levels for 28 consecutive hours. The testing showed that the system operated as expected and that the reactor is highly tolerant of possible failure conditions and transients. The key feature demonstrated was the ability of the reactor to load-follow the demand of the power conversion system. The thermal power of the test ranged from 1.5 to 5.0 kW(thermal), with a fuel temperature up to 880°C. Each 80-W(electric)–rated Stirling converter produced ~90 W(electric) at a component efficiency of ~35% and an overall system efficiency of ~25%.

David I. Poston↗

Heat Pipe Development For Space Fission Demonstration Missions

NASA is currently formulating a flight mission that will demonstrate a 10 kWe nuclear electric fission power system for use on the lunar surface. While preliminary mission concepts leverage the successful Kilopower Reactor Using Stirling Technology ground prototype demonstration of a 1 kWe reactor, there are significant engineering challenges associated with adapting that prototype reactor for flight. One of these challenges is to modify the high temperature sodium heat pipes for use in space operation. Ongoing technical work at the NASA Glenn Research Center seeks to address several key areas of heat pipe development, focusing on fluid return under reduced or microgravity conditions and improved interfaces for both the reactor and the power conversion ends of the heat pipe.

Fission↗

Consolidation of A Sodium Heat Pipe and Stirling Engine for Fission Surface Power

The Consolidated Heat Pipe (CHP) is a new design in which a sodium heat pipe is welded directly to the hot end of the Stirling engine to deliver thermal power more efficiently. The new integrated interface aims to reduce the large temperature drop (about 120 °C) that was measured across the bolted clamp joint between the Stirling engine and the heat pipes during the Kilopower Reactor Using Stirling TechnologY (KRUSTY) test from 20181. Initial testing and characterization of the CHP was performed in ambient air at the NASA Glenn Research Center (GRC). In the test, the heat pipe evaporator section was heated with a tube furnace. The thermal power was then transported to the Stirling engine integrated with a linear alternator that produced electrical power. The CHP has been tested at a hot end temperature ranging from 600 °C - 800 °C and a variety of other Stirling engine parameters (cold end temperature, piston amplitude and pressure). The results show that the temperature drop between the Stirling engine and the heat pipe has been reduced to 2°C - 4 °C. An overall temperature drop of 20 °C – 60 °C was also noted within the heat pipe depending on the combination of parameters mentioned above. Overall, it has been shown that the new Consolidated Heat Pipe design significantly improved the thermal interface to the Stirling engine.

Consolidated↗