A boiling water reactor relies on which single substance to serve simultaneously as moderator, coolant, and working fluid________________?
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Answer: A. ordinary fluid
Explanation
A boiling water reactor utilizes ordinary water to perform multiple vital core functions simultaneously. It acts as a neutron moderator to slow down fast fission neutrons effectively. It serves as both the reactor coolant and the working fluid generating steam for turbines. Ordinary water consists of lightweight hydrogen and oxygen atoms, making it an effective neutron moderator. Water has high specific heat capacity, allowing it to transport large quantities of thermal energy. Direct boiling within the core eliminates the need for a separate secondary steam generator.
Using ordinary water simplifies boiling water reactor plant design compared to dual-fluid reactor systems. This design is widely implemented in commercial nuclear power stations generating electricity globally. Water purity must be strictly maintained to prevent radioactive activation of mineral impurities. Heavy water contains deuterium and is typically used in reactors designed for natural uranium fuel. Molten lead is utilized as a coolant in fast reactors rather than standard boiling water systems. Hydrogen gas serves as a generator cooling medium rather than a reactor moderator and coolant.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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