Propulsion-type nuclear reactors typically employ_________________?
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Answer: B. molten lead
Explanation
Nuclear propulsion systems require compact reactors capable of delivering high power densities rapidly. Molten lead or lead-bismuth eutectic alloys serve as excellent high-temperature reactor coolants. These liquid metal coolants allow compact propulsion reactors to operate efficiently without pressurization. Liquid metal coolants possess high thermal conductivity and boiling points compared to water. Naval reactors and space nuclear prototypes benefit immensely from lightweight liquid metal loops. Molten lead alloys remain liquid across a broad temperature range suitable for power conversion.
Submarine and naval vessel propulsion relies on specialized reactors designed for tight spatial constraints. Liquid metal cooling technology prevents catastrophic boiling hazards associated with pressurized water systems. Engineering these systems requires managing severe material corrosion caused by flowing liquid metals. Option A is wrong because natural uranium is insufficiently enriched for compact propulsion units. Option C is too imprecise as a technical specification for marine reactor fuel design. Option D and E name specific elements that are not standard liquid coolants in propulsion systems.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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