Reaching a critical state within a nuclear reactor unit implies that_______________?
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Answer: D. chain reaction that causes automatic splitting of the fuel nuclei has been established
Explanation
Reaching a critical state means that each nuclear fission event triggers exactly one subsequent fission. This balanced rate allows the nuclear chain reaction to sustain itself continuously over time. The automatic splitting of fuel nuclei continues steadily without requiring external neutron sources. Nuclear reactors rely on uranium or plutonium fuel elements to maintain this self-sustaining chain reaction. The effective multiplication factor exactly equals one when a reactor achieves this critical operational state. Control rods are carefully adjusted by operators to safely reach and maintain this exact criticality.
Achieving criticality is the fundamental prerequisite for generating commercial electricity in nuclear power stations. Reactor operators must monitor neutron flux constantly to ensure the facility remains in a controlled state. Operating at criticality allows steady steam production to drive large industrial turbine generators efficiently. Option A is wrong because critical state does not automatically mean maximum rated power output capacity. Option B is incorrect because generating above rated capacity would mean entering a supercritical condition. Option C and E are incorrect because criticality is a normal controlled process generating substantial heat.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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