Within a boiling water reactor design, the moderating medium is__________________?
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Answer: A. coolant itself
Explanation
Boiling water reactors utilize ordinary light water simultaneously as both coolant and neutron moderator medium. The circulating water molecules effectively slow down fast neutrons while simultaneously removing heat from the core. This dual role simplifies reactor design by combining moderating and heat transfer functions into one fluid. Light water consists of hydrogen and oxygen atoms where hydrogen nuclei have masses very close to neutrons. Colliding with hydrogen atoms allows fast neutrons to lose energy rapidly through simple elastic scattering events. Boiling water reactors allow the coolant to boil directly inside the pressure vessel producing driving steam.
Ferrite rods are magnetic materials and possess no suitable nuclear properties for moderating fast neutrons. Graphite rods serve as moderators in gas-cooled reactor designs rather than standard boiling water systems. Liquid metal sodium operates as an unmoderated coolant primarily utilized in fast breeder reactor technologies.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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