Nuclear thermal space propulsion update

BWXT provided progress updates and technology demonstrations related to BWXT’s nuclear thermal propulsion (NTP) program. Jim Reuter, NASA’s acting associate administrator of STMD, toured BWXT’s Advanced Technology Lab in Lynchburg, Virginia to learn more about BWXT’s progress on the program that could support a future crewed mission to Mars.

Reuter watched demonstrations of three key technologies that BWXT has been developing to support the NTP program:

1) Advanced welding – BWXT demonstrated a new welding technology developed specifically for NASA fuel element fabrication.

2) Metallography – Technologists showed how they solve challenges in fabricating specialized materials used in NTP development.

3) Fuel Element Filling – The company presented a simple yet innovative way that it can fill fuel elements.

LEU nuclear thermal propulsion

Current development of 500 MW LEU CERMET fuel reactor for manned space applications.

* Design of 19.75% Enriched Ceramic Metallic (CERMET) Tungsten-Clad fuel
* Nuclear, thermal-hydraulics and mechanical design of the reactor
* Licensing and design support for full-scale full-thrust ground test of the NTP engine

BWXT’S SPACE NUCLEAR EXPERIENCE
Space Nuclear Thermal Propulsion

Formerly classified advanced technology design to develop and test high-performance nuclear reactor rocket engine for military applications.

Particle bed fuel
Mechanical, nuclear and thermal-hydraulic design of the core
Reactor control and auxiliary systems

Small Ex-core Heatpipe Thermionic Reactor

Program to develop a nuclear reactor in the power range of 10 to 40 kW for space applications.

Mechanical and Nuclear Design of UO2-Tungsten Clad Fuel
Mechanical, nuclear and thermal design of the core and shield components
Design of the reactor control and reactor support systems
Extended reactor design to include propulsion (Bi-Modal) capability

Nuclear Thermal Rocket Bi-Modal Reactor

Nuclear thermal rocket program to provide Bi-Modal propulsion capability for future human exploration missions to the Moon and Mars and generating electrical power for spacecraft systems.

Design studies for Various Fuel Types and Configurations including: PBR, UO2-Moly CERMET and Twisted Ribbon Ternary Carbide fuel forms
Mechanical, nuclear and thermal design of the various core configurations and shield designs

70 thoughts on “Nuclear thermal space propulsion update”

  1. My own view is that if you’re going to deploy the effort to bust through anti-nuke hysteria, why do it for something with a measly 8-900 ISP? Go big or don’t go at all. 30K ISP or don’t bother. I see nuclear space propulsion as something that’s likely to take off once we have colonies in space. The colonists will be dealing with radiation as a matter of routine, and so won’t be paranoid about it. And living on the raw frontier, they won’t be willing to throw away the huge advantages. Musk thinks his Mars colony will be solar powered. Want to bet the colonists don’t build a bootleg fission reactor if the colony really takes off?

    Reply
  2. My own view is that if you’re going to deploy the effort to bust through anti-nuke hysteria why do it for something with a measly 8-900 ISP? Go big or don’t go at all. 30K ISP or don’t bother.I see nuclear space propulsion as something that’s likely to take off once we have colonies in space. The colonists will be dealing with radiation as a matter of routine and so won’t be paranoid about it. And living on the raw frontier they won’t be willing to throw away the huge advantages.Musk thinks his Mars colony will be solar powered. Want to bet the colonists don’t build a bootleg fission reactor if the colony really takes off?

    Reply
  3. Eh, not necessarily. Boosting something in LEO to above the Van Allens is a good job for a rotating tether, which itself needs a high ISP low thrust system for station keeping. Though I think electrodynamic tether propulsion is probably a better fit. But right about the outer system. We’ve already had one mission fail because they insisted on it being solar powered even though the odds of ending up in a shadow were high.

    Reply
  4. Eh not necessarily. Boosting something in LEO to above the Van Allens is a good job for a rotating tether which itself needs a high ISP low thrust system for station keeping. Though I think electrodynamic tether propulsion is probably a better fit.But right about the outer system. We’ve already had one mission fail because they insisted on it being solar powered even though the odds of ending up in a shadow were high.

    Reply
  5. Until you can take the ‘solar’ out of those, you’re not going very far into the solar system with them. “…though they have lower thrust levels.” And there are times when thrust *matters,* even at reduced specific impulse, especially for human LEO departure. You do *not* want to spend the first few weeks of the mission slowly spiraling out in the VanAllens as you work your way up to escape velocity. You want to cut across them quickly, as was done in Apollo. Sorry, but that’s going to be chemical, or nuclear-thermal.

    Reply
  6. Until you can take the ‘solar’ out of those you’re not going very far into the solar system with them….though they have lower thrust levels.””And there are times when thrust *matters””* even at reduced specific impulse especially for human LEO departure.You do *not* want to spend the first few weeks of the mission slowly spiraling out in the VanAllens as you work your way up to escape velocity. You want to cut across them quickly as was done in Apollo.Sorry but that’s going to be chemical”” or nuclear-thermal.”””

    Reply
  7. I did write ‘much’ farther. In the case of the Juno mission I think that was a case of pushing the bleeding edge of what is doable with solar because they didn’t have enough Pu238 to use the better option of an RTG, & something like the Kilopower reactor wasn’t available either.

    Reply
  8. I did write ‘much’ farther.In the case of the Juno mission I think that was a case of pushing the bleeding edge of what is doable with solar because they didn’t have enough Pu238 to use the better option of an RTG & something like the Kilopower reactor wasn’t available either.

    Reply
  9. The ‘dusty’ reactor using particles of oxide fuel has been discussed (Brett likes it), but considering that normal reactors have fuel atom densities on the order of maybe 1E22/cm/cm/cm I don’t really see how the system could work – maybe if the chamber was of 100m dimension? It’s a simple calculation in MCNP actually, but not worth doing because it isn’t apparent to me how you would get the energy out of the system. Hey, I wrote this reply on my new Raspberry Pi 3 B+. Amazing this works better than the desktop I built in 2004.

    Reply
  10. Wasn’t there some kind of a gas based NTR system, I don’t really know the history, I thought it performed better than the whole gases moving around rods concept, but it was also more dangerous or something?

    Reply
  11. I did 2 or 3 design studies in grad school on a pulsed IEC fusion reactor based system architectures, based loosely on some low power plasma physics we did on the IEC we had in our lab. We just kinda like said “ok let’s assume you can get breakeven out of this device if you get this kinda current scaling and this little Brem losses, etc etc., here’s your output power” with p-B11. So you could basically pump out the alpha particles from that reaction, as a jet beam, because the IEC has this functioning condition called ‘jet mode’ where it produces a plasma jet. You could just pump out alpha particles and get like 200,000s of ISP but ofc thrust is like… on par with an ion thruster or less, because the exhaust products are so light. But we did a followup iteration where I ran the numbers for pumping cold hydrogen into it and you’d amp up the thrust and sacrifice ISP because of all the particle kinetics, you’d get like… 50,000s and like 200 N of thrust. Then I looked at pumping drops of liquid indium into it from a FEEP device, getting like 50,000s at like a couple kilonewtons. Now that big asterisk right is getting a breakeven fusion device. Even if you don’t have a breakeven device and you power it somehow, solar, nuclear reactor, whatever, you still have a crazy paradigm shift in propulsion. This kind of stuff and a lot of similar concepts in plasma propulsion leapfrogs NTR.

    Reply
  12. The ‘dusty’ reactor using particles of oxide fuel has been discussed (Brett likes it) but considering that normal reactors have fuel atom densities on the order of maybe 1E22/cm/cm/cm I don’t really see how the system could work – maybe if the chamber was of 100m dimension? It’s a simple calculation in MCNP actually but not worth doing because it isn’t apparent to me how you would get the energy out of the system. Hey I wrote this reply on my new Raspberry Pi 3 B+. Amazing this works better than the desktop I built in 2004.

    Reply
  13. Wasn’t there some kind of a gas based NTR system I don’t really know the history I thought it performed better than the whole gases moving around rods concept but it was also more dangerous or something?

    Reply
  14. I did 2 or 3 design studies in grad school on a pulsed IEC fusion reactor based system architectures based loosely on some low power plasma physics we did on the IEC we had in our lab. We just kinda like said ok let’s assume you can get breakeven out of this device if you get this kinda current scaling and this little Brem losses” etc etc.” here’s your output power”” with p-B11. So you could basically pump out the alpha particles from that reaction”” as a jet beam because the IEC has this functioning condition called ‘jet mode’ where it produces a plasma jet. You could just pump out alpha particles and get like 200000s of ISP but ofc thrust is like… on par with an ion thruster or less because the exhaust products are so light. But we did a followup iteration where I ran the numbers for pumping cold hydrogen into it and you’d amp up the thrust and sacrifice ISP because of all the particle kinetics you’d get like… 50000s and like 200 N of thrust. Then I looked at pumping drops of liquid indium into it from a FEEP device getting like 50000s at like a couple kilonewtons. Now that big asterisk right is getting a breakeven fusion device. Even if you don’t have a breakeven device and you power it somehow solar nuclear reactor whatever”” you still have a crazy paradigm shift in propulsion. This kind of stuff and a lot of similar concepts in plasma propulsion leapfrogs NTR.”””

    Reply
  15. However, I think you would want to power electric drives with the Kikopower reactor for any missions going much farther from the sun than Mars.

    Reply
  16. However I think you would want to power electric drives with the Kikopower reactor for any missions going much farther from the sun than Mars.

    Reply
  17. NTR is already obsolete. Solar-Thermal can reach the same exhaust velocity without the weight and cost overhead of nuclear. Solar-Electric (ion & plasma engines) can reach higher exhaust velocities by a factor of 3-5, though they have lower thrust levels. Note: is there a way to edit posts on Vuukle?

    Reply
  18. NTR is already obsolete. Solar-Thermal can reach the same exhaust velocity without the weight and cost overhead of nuclear. Solar-Electric (ion & plasma engines) can reach higher exhaust velocities by a factor of 3-5 though they have lower thrust levels.Note: is there a way to edit posts on Vuukle?

    Reply
  19. NTER seems like a cheap-ish win in terms of NTR design variants, but I guess since ESA is all over that it may be difficult to develop in the US? Always good to look at the BeyondNERVA blog for more info.

    Reply
  20. NTER seems like a cheap-ish win in terms of NTR design variants but I guess since ESA is all over that it may be difficult to develop in the US?Always good to look at the BeyondNERVA blog for more info.

    Reply
  21. The ‘dusty’ reactor using particles of oxide fuel has been discussed (Brett likes it), but considering that normal reactors have fuel atom densities on the order of maybe 1E22/cm/cm/cm I don’t really see how the system could work – maybe if the chamber was of 100m dimension? It’s a simple calculation in MCNP actually, but not worth doing because it isn’t apparent to me how you would get the energy out of the system. Hey, I wrote this reply on my new Raspberry Pi 3 B+. Amazing this works better than the desktop I built in 2004.

    Reply
  22. The ‘dusty’ reactor using particles of oxide fuel has been discussed (Brett likes it) but considering that normal reactors have fuel atom densities on the order of maybe 1E22/cm/cm/cm I don’t really see how the system could work – maybe if the chamber was of 100m dimension? It’s a simple calculation in MCNP actually but not worth doing because it isn’t apparent to me how you would get the energy out of the system. Hey I wrote this reply on my new Raspberry Pi 3 B+. Amazing this works better than the desktop I built in 2004.

    Reply
  23. Wasn’t there some kind of a gas based NTR system, I don’t really know the history, I thought it performed better than the whole gases moving around rods concept, but it was also more dangerous or something?

    Reply
  24. Wasn’t there some kind of a gas based NTR system I don’t really know the history I thought it performed better than the whole gases moving around rods concept but it was also more dangerous or something?

    Reply
  25. I did 2 or 3 design studies in grad school on a pulsed IEC fusion reactor based system architectures, based loosely on some low power plasma physics we did on the IEC we had in our lab. We just kinda like said “ok let’s assume you can get breakeven out of this device if you get this kinda current scaling and this little Brem losses, etc etc., here’s your output power” with p-B11. So you could basically pump out the alpha particles from that reaction, as a jet beam, because the IEC has this functioning condition called ‘jet mode’ where it produces a plasma jet. You could just pump out alpha particles and get like 200,000s of ISP but ofc thrust is like… on par with an ion thruster or less, because the exhaust products are so light. But we did a followup iteration where I ran the numbers for pumping cold hydrogen into it and you’d amp up the thrust and sacrifice ISP because of all the particle kinetics, you’d get like… 50,000s and like 200 N of thrust. Then I looked at pumping drops of liquid indium into it from a FEEP device, getting like 50,000s at like a couple kilonewtons. Now that big asterisk right is getting a breakeven fusion device. Even if you don’t have a breakeven device and you power it somehow, solar, nuclear reactor, whatever, you still have a crazy paradigm shift in propulsion. This kind of stuff and a lot of similar concepts in plasma propulsion leapfrogs NTR.

    Reply
  26. I did 2 or 3 design studies in grad school on a pulsed IEC fusion reactor based system architectures based loosely on some low power plasma physics we did on the IEC we had in our lab. We just kinda like said ok let’s assume you can get breakeven out of this device if you get this kinda current scaling and this little Brem losses” etc etc.” here’s your output power”” with p-B11. So you could basically pump out the alpha particles from that reaction”” as a jet beam because the IEC has this functioning condition called ‘jet mode’ where it produces a plasma jet. You could just pump out alpha particles and get like 200000s of ISP but ofc thrust is like… on par with an ion thruster or less because the exhaust products are so light. But we did a followup iteration where I ran the numbers for pumping cold hydrogen into it and you’d amp up the thrust and sacrifice ISP because of all the particle kinetics you’d get like… 50000s and like 200 N of thrust. Then I looked at pumping drops of liquid indium into it from a FEEP device getting like 50000s at like a couple kilonewtons. Now that big asterisk right is getting a breakeven fusion device. Even if you don’t have a breakeven device and you power it somehow solar nuclear reactor whatever”” you still have a crazy paradigm shift in propulsion. This kind of stuff and a lot of similar concepts in plasma propulsion leapfrogs NTR.”””

    Reply
  27. I did write ‘much’ farther. In the case of the Juno mission I think that was a case of pushing the bleeding edge of what is doable with solar because they didn’t have enough Pu238 to use the better option of an RTG, & something like the Kilopower reactor wasn’t available either.

    Reply
  28. I did write ‘much’ farther.In the case of the Juno mission I think that was a case of pushing the bleeding edge of what is doable with solar because they didn’t have enough Pu238 to use the better option of an RTG & something like the Kilopower reactor wasn’t available either.

    Reply
  29. The ‘dusty’ reactor using particles of oxide fuel has been discussed (Brett likes it), but considering that normal reactors have fuel atom densities on the order of maybe 1E22/cm/cm/cm I don’t really see how the system could work – maybe if the chamber was of 100m dimension? It’s a simple calculation in MCNP actually, but not worth doing because it isn’t apparent to me how you would get the energy out of the system. Hey, I wrote this reply on my new Raspberry Pi 3 B+. Amazing this works better than the desktop I built in 2004.

    Reply
  30. My own view is that if you’re going to deploy the effort to bust through anti-nuke hysteria, why do it for something with a measly 8-900 ISP? Go big or don’t go at all. 30K ISP or don’t bother. I see nuclear space propulsion as something that’s likely to take off once we have colonies in space. The colonists will be dealing with radiation as a matter of routine, and so won’t be paranoid about it. And living on the raw frontier, they won’t be willing to throw away the huge advantages. Musk thinks his Mars colony will be solar powered. Want to bet the colonists don’t build a bootleg fission reactor if the colony really takes off?

    Reply
  31. My own view is that if you’re going to deploy the effort to bust through anti-nuke hysteria why do it for something with a measly 8-900 ISP? Go big or don’t go at all. 30K ISP or don’t bother.I see nuclear space propulsion as something that’s likely to take off once we have colonies in space. The colonists will be dealing with radiation as a matter of routine and so won’t be paranoid about it. And living on the raw frontier they won’t be willing to throw away the huge advantages.Musk thinks his Mars colony will be solar powered. Want to bet the colonists don’t build a bootleg fission reactor if the colony really takes off?

    Reply
  32. Eh, not necessarily. Boosting something in LEO to above the Van Allens is a good job for a rotating tether, which itself needs a high ISP low thrust system for station keeping. Though I think electrodynamic tether propulsion is probably a better fit. But right about the outer system. We’ve already had one mission fail because they insisted on it being solar powered even though the odds of ending up in a shadow were high.

    Reply
  33. Eh not necessarily. Boosting something in LEO to above the Van Allens is a good job for a rotating tether which itself needs a high ISP low thrust system for station keeping. Though I think electrodynamic tether propulsion is probably a better fit.But right about the outer system. We’ve already had one mission fail because they insisted on it being solar powered even though the odds of ending up in a shadow were high.

    Reply
  34. Wasn’t there some kind of a gas based NTR system, I don’t really know the history, I thought it performed better than the whole gases moving around rods concept, but it was also more dangerous or something?

    Reply
  35. I did 2 or 3 design studies in grad school on a pulsed IEC fusion reactor based system architectures, based loosely on some low power plasma physics we did on the IEC we had in our lab. We just kinda like said “ok let’s assume you can get breakeven out of this device if you get this kinda current scaling and this little Brem losses, etc etc., here’s your output power” with p-B11. So you could basically pump out the alpha particles from that reaction, as a jet beam, because the IEC has this functioning condition called ‘jet mode’ where it produces a plasma jet. You could just pump out alpha particles and get like 200,000s of ISP but ofc thrust is like… on par with an ion thruster or less, because the exhaust products are so light. But we did a followup iteration where I ran the numbers for pumping cold hydrogen into it and you’d amp up the thrust and sacrifice ISP because of all the particle kinetics, you’d get like… 50,000s and like 200 N of thrust. Then I looked at pumping drops of liquid indium into it from a FEEP device, getting like 50,000s at like a couple kilonewtons. Now that big asterisk right is getting a breakeven fusion device. Even if you don’t have a breakeven device and you power it somehow, solar, nuclear reactor, whatever, you still have a crazy paradigm shift in propulsion. This kind of stuff and a lot of similar concepts in plasma propulsion leapfrogs NTR.

    Reply
  36. I did write ‘much’ farther.
    In the case of the Juno mission I think that was a case of pushing the bleeding edge of what is doable with solar because they didn’t have enough Pu238 to use the better option of an RTG, & something like the Kilopower reactor wasn’t available either.

    Reply
  37. My own view is that if you’re going to deploy the effort to bust through anti-nuke hysteria, why do it for something with a measly 8-900 ISP? Go big or don’t go at all. 30K ISP or don’t bother.

    I see nuclear space propulsion as something that’s likely to take off once we have colonies in space. The colonists will be dealing with radiation as a matter of routine, and so won’t be paranoid about it. And living on the raw frontier, they won’t be willing to throw away the huge advantages.

    Musk thinks his Mars colony will be solar powered. Want to bet the colonists don’t build a bootleg fission reactor if the colony really takes off?

    Reply
  38. Eh, not necessarily. Boosting something in LEO to above the Van Allens is a good job for a rotating tether, which itself needs a high ISP low thrust system for station keeping. Though I think electrodynamic tether propulsion is probably a better fit.

    But right about the outer system. We’ve already had one mission fail because they insisted on it being solar powered even though the odds of ending up in a shadow were high.

    Reply
  39. Until you can take the ‘solar’ out of those, you’re not going very far into the solar system with them. “…though they have lower thrust levels.” And there are times when thrust *matters,* even at reduced specific impulse, especially for human LEO departure. You do *not* want to spend the first few weeks of the mission slowly spiraling out in the VanAllens as you work your way up to escape velocity. You want to cut across them quickly, as was done in Apollo. Sorry, but that’s going to be chemical, or nuclear-thermal.

    Reply
  40. Until you can take the ‘solar’ out of those you’re not going very far into the solar system with them….though they have lower thrust levels.””And there are times when thrust *matters””* even at reduced specific impulse especially for human LEO departure.You do *not* want to spend the first few weeks of the mission slowly spiraling out in the VanAllens as you work your way up to escape velocity. You want to cut across them quickly as was done in Apollo.Sorry but that’s going to be chemical”” or nuclear-thermal.”””

    Reply
  41. However, I think you would want to power electric drives with the Kikopower reactor for any missions going much farther from the sun than Mars.

    Reply
  42. However I think you would want to power electric drives with the Kikopower reactor for any missions going much farther from the sun than Mars.

    Reply
  43. NTR is already obsolete. Solar-Thermal can reach the same exhaust velocity without the weight and cost overhead of nuclear. Solar-Electric (ion & plasma engines) can reach higher exhaust velocities by a factor of 3-5, though they have lower thrust levels. Note: is there a way to edit posts on Vuukle?

    Reply
  44. NTR is already obsolete. Solar-Thermal can reach the same exhaust velocity without the weight and cost overhead of nuclear. Solar-Electric (ion & plasma engines) can reach higher exhaust velocities by a factor of 3-5 though they have lower thrust levels.Note: is there a way to edit posts on Vuukle?

    Reply
  45. Until you can take the ‘solar’ out of those, you’re not going very far into the solar system with them.

    “…though they have lower thrust levels.”

    And there are times when thrust *matters,* even at reduced specific impulse, especially for human LEO departure.

    You do *not* want to spend the first few weeks of the mission slowly spiraling out in the VanAllens as you work your way up to escape velocity. You want to cut across them quickly, as was done in Apollo.

    Sorry, but that’s going to be chemical, or nuclear-thermal.

    Reply
  46. NTER seems like a cheap-ish win in terms of NTR design variants, but I guess since ESA is all over that it may be difficult to develop in the US? Always good to look at the BeyondNERVA blog for more info.

    Reply
  47. NTER seems like a cheap-ish win in terms of NTR design variants but I guess since ESA is all over that it may be difficult to develop in the US?Always good to look at the BeyondNERVA blog for more info.

    Reply
  48. NTR is already obsolete. Solar-Thermal can reach the same exhaust velocity without the weight and cost overhead of nuclear. Solar-Electric (ion & plasma engines) can reach higher exhaust velocities by a factor of 3-5, though they have lower thrust levels.

    Note: is there a way to edit posts on Vuukle?

    Reply
  49. NTER seems like a cheap-ish win in terms of NTR design variants, but I guess since ESA is all over that it may be difficult to develop in the US?

    Always good to look at the BeyondNERVA blog for more info.

    Reply

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