Have pulsed fission reactors got any potential in nuclear energy?

[DyerMaker]

How did you find PF?: Searched for some forum about mechanical engineering in Google

Do pulsed nuclear fission reactors have any chances to be used in nuclear power?
If the answer is "no" is that just because of no need in pulsed operation mode while having a common one, are there any more complicated issues like ones with delayed neutrons or both these reasons?

Thank you!

 

[berkeman]

Welcome to PF.

Can you post a link to information about that type of reactor? Are you asking about fission, or a pulsed fusion reactor like NIF at LLNL...?

https://en.wikipedia.org/wiki/National_Ignition_Facility

 

[DyerMaker]

Thank you for you reply.
I am asking about pulsed fission reactors, like ones described here: https://www.euronuclear.org/glossary/pulsed-reactor/
It is claimed that's the only reasonable way to use them is to use them in research studies, but not explained why.

 

[Astronuc]

Thank you for you reply.
I am asking about pulsed fission reactors, like ones described here: https://www.euronuclear.org/glossary/pulsed-reactor/
It is claimed that's the only reasonable way to use them is to use them in research studies, but not explained why.

Note in the Euronuclear article, it states "FRMZ, research reactor of the university of Mayence in Germany, type TRIGA-Mark-II; pulse power 250 MW, permanent power 0.1 MW." Pulses are typically in the 10's of ms (milli-seconds) for looking at 'transient behavior' of nuclear fuel, usually in response to a reactivity accident, which is a 'hypothetical' accident. The 'permanent' of 0.1 MW should be 'steady-state' power. After a pulse/test, the fuel is normally inspected to see if integrity is maintained.

Power reactors operate normally at constant power, although a reactor may 'load-follow'. Power maneuvering may be unrestricted, i.e., no restriction on power ascension (ramp) rates, but normally it's a few %/hr to 10-40%/hr, depending on the conditioning of the fuel. Often, if the fuel mechanical integrity is not limiting, the balance of plant (response of turbine/generator) is limiting. Another concern would be pressure pulses in the cooling system and potential for rupture of the piping or coolant boundary, as well as fatigue of the piping/pressure boundary.

There are technical limits on peak fuel enthalpy (stored energy) and temperature. With about 30% of fission products being isotopes of Xe and Kr (noble gases) with another significant fraction being Br, I, Rb, Cs, which are volatile well below the melting point of UO₂/MOX fuel, the fuel could potentially balloon or rupture is the fuel temperature became too great, especially near the surface of the fuel.

Pulses in 'pulsed' reactor operation are completed well before the longer-lived delayed neutron precursors release neutrons, but on may observe their effect in the 'tail' after the pulse.

Utilities (power reactor operators) do not pulse their power reactors, nor would they plan to do so.

 

[DyerMaker]

Note in the Euronuclear article, it states "FRMZ, research reactor of the university of Mayence in Germany, type TRIGA-Mark-II; pulse power 250 MW, permanent power 0.1 MW." Pulses are typically in the 10's of ms (milli-seconds) for looking at 'transient behavior' of nuclear fuel, usually in response to a reactivity accident, which is a 'hypothetical' accident. The 'permanent' of 0.1 MW should be 'steady-state' power. After a pulse/test, the fuel is normally inspected to see if integrity is maintained.

Power reactors operate normally at constant power, although a reactor may 'load-follow'. Power maneuvering may be unrestricted, i.e., no restriction on power ascension (ramp) rates, but normally it's a few %/hr to 10-40%/hr, depending on the conditioning of the fuel. Often, if the fuel mechanical integrity is not limiting, the balance of plant (response of turbine/generator) is limiting. Another concern would be pressure pulses in the cooling system and potential for rupture of the piping or coolant boundary, as well as fatigue of the piping/pressure boundary.

There are technical limits on peak fuel enthalpy (stored energy) and temperature. With about 30% of fission products being isotopes of Xe and Kr (noble gases) with another significant fraction being Br, I, Rb, Cs, which are volatile well below the melting point of UO₂/MOX fuel, the fuel could potentially balloon or rupture is the fuel temperature became too great, especially near the surface of the fuel.

Pulses in 'pulsed' reactor operation are completed well before the longer-lived delayed neutron precursors release neutrons, but on may observe their effect in the 'tail' after the pulse.

Utilities (power reactor operators) do not pulse their power reactors, nor would they plan to do so.

Thank you!

 

[SongDog]

Well, there's always Project Orion, but we can forget about using it near Earth.