Can a nuclear reactor operate at any power? or only at the power at which it is critical?

Manchester

Are there ways to reduce power while maintaining criticality?



Camargo

Yes, a nuclear reactor buttocks behave at any facility, it is most effective at 100% power, where it was fitted to react. An operating reactor is normally a critical reactor. Let's define critical, master critical together with understudy-critical. A reactor duff be critical, pinch-hitter-critical or super-critical on tap virtually any know-how level. A deprecatori reactor has its neutron population invariable, that means facility level is in residence the same. Keff=1A pinch-hitter-critical reactor has a decreasing neutron citizenry, power level is decreasing. Keff=<1A big Daddy-carping reactor has an increasing neutron citizenry, power focus is flowering. Keff=>1



Plant City

The word is sub-critical and it can operate at any power safely as long as it remains there. If it goes critical then you will have another Chernobyl. Three mile island did not go critical but came close.



Ida

In theory a reactor can operate at any power level. However, there are limits to various components like steam generators, turbines, feed water pumps, etc. These things were designed for maximum power, not puttering around. Also, there are some physics characteristics of some reactor cores that result in them behaving differently at lower power levels. The Chernobyl accident was caused, in part, by operating that reactor at a low power level when the control system wasn't designed for it and the reactor physics made it unsafe so that the system became unstable and eventually got out of control. There are huge differences in reactor physics between boiling water reactors, pressurized water reactors, CANDU reactors, RBMK reactors, etc. Generally, though, it is a matter of how much water is flowing through the core to the turbines. If you crank down the water flow rate, then you insert the control rods a little, the reactor will achieve a new critical point at this lower rate. To create a sustained amount of power, the reactor must be critical. If it is sub-critical, the heat generation stops. If it is super-critical something will overheat and the safety systems will shut it down.