Pentagon Wants Mobile Nuclear Reactors

[ronwagn + 6,290]

https://www.defensenews.com/smr/nuclear-arsenal/2020/03/09/pentagon-to-award-mobile-nuclear-reactor-contracts-this-week/

What could possibly go wrong? Maybe a rocket propelled grenade, mortar, IED, drone strike? RCW

[Marcin2 + 724]

Ron, it shows how creative and smart MIC can be in new proposals to waste taxpayers money. Fantastic people , if their brain power could be harnessed for the benefit of the nation.

The story is good cause Russians already developed small nuclear reactors 40 MW ? for usage as floating power plants for towns in Arctic.

Rolls-Royce was talking recently about 225/450 reactors.

Alternative for 40 MW floating power plant is crude oil generator together with 50,000 tons of fuel for 1 year of operations.

Makes sense in Russia not in US.

And should be floating or very  dangerous and very costly exercise.

They also could just change designs from small French nuclear subs reactors.

Actually there was small nuclear reactor on US military submersible vessel - should be mobile/ portable cause was small.

 

 

Edited March 10, 2020 by Marcin2
Edit

[footeab@yahoo.com + 2,131]

6 hours ago, ronwagn said:

https://www.defensenews.com/smr/nuclear-arsenal/2020/03/09/pentagon-to-award-mobile-nuclear-reactor-contracts-this-week/

What could possibly go wrong? Maybe a rocket propelled grenade, mortar, IED, drone strike? RCW

From my time working on ~100MW reactors, anything smaller than this ~requires plutonium to function for more than a VERY brief period as the efficiency drops close to zero as the section density of the fuel is not great enough.  I believe this contract is a 100% red herring... get the thing built to placate the dumb asses in congress/bureaucracy for "non proliferation", that effectively does not function with low enriched uranium, and then switch to Plutonium.  The ~10 year refueling cycle mentioned in article bellies my statement.  The 100MW modular reactors we were working on would have had a pathetic thermal efficiency of ~15%, 20% at best(short period only) and only function for ~2 yrs, well can be "longer" but efficiency drops into no mans land...  Sure as Hell did not go past 5 years. 

Uh, you do realize that the reactor vessel is ~10cm or greater thickness of hardened stainless steel right and loss of pressure automatically opens the top pressure negative valve dropping bottom of tank and the core out the bottom into rod holding cells?  Yes?

What is criminal is that our CURRENT nuclear reactors are not built as described above.  3 mile island, Cherynobel, Fukishima would have never happened. 

PS: Personally I think they are thinking about SPACE(moon/mars), not land or ocean.

[ronwagn + 6,290]

Uh, you do realize that the reactor vessel is ~10cm or greater thickness of hardened stainless steel right and loss of pressure automatically opens the top pressure negative valve dropping bottom of tank and the core out the bottom into rod holding cells?  Yes?

Please explain this information for the uninitiated such as myself. 

[footeab@yahoo.com + 2,131]

3 hours ago, ronwagn said:

Uh, you do realize that the reactor vessel is ~10cm or greater thickness of hardened stainless steel right and loss of pressure automatically opens the top pressure negative valve dropping bottom of tank and the core out the bottom into rod holding cells?  Yes?

Please explain this information for the uninitiated such as myself. 

Uh, first: I screwed up: I wrote 100MW above, Ours was 20MW; the one I worked on.  The 100MW was the Westinghouse version we always used to compare ours.  😯

The small nuclear modular reactors, I believe ALL of them, at least ALL of them when I was working on them required positive working pressure, but not too much positive pressure.  In other words had 2 different valves.  Either failed, whole thing scrams.  Too low of a pressure say to a leak, would blow the low pressure valve and the mechanism HOLDING the fuel rods from the TOP, AND the bottom plug up(bottom seal/refueling entrance) and IN place would FALL out the bottom of the reactor.  Too High of a pressure, and same thing.  Too hot of a temperature(pool they were operating in drained)... the bottom plug would melt out and the melted slag would descend into an emergency tube/underground box filled with boron splitting up the reactor killing the fission.  Hrmm, A picture would be worth a 1000 words here, maybe 10k words😎

Now the version I was working on(ORL/INL/PNL) could get stuck running at 100%, without the turbine operational, and the heat conduction of its eggshell was sufficient, if it was submersed in a pool of water, to never melt down. 

The biggest problem we had was to meet the above criteria, plus many more, we required a reactor that was ~65 feet long by 14 feet wide for 20MW @ 18% efficiency conversion(fuel burn was astronomical), and the core size was held at approximately ~1 ft in diameter by ~8ft long core, had 4" thick stainless steel walls, and had to be moved by a very specialized railroad car.  This size was required to keep the thermal safety properties and the core diameter/length.  The 65 feet was required to create a thermal chimney out of the core from which a heat exchanger can pull the heat without being destroyed by nuclear bombardment and hold all the safety structures etc.  AKA NO PUMPS required to cool it.  No external power required to run it.  No sensors requiring active monitoring.  No human required.  No computer required.  100% PASSIVE. 

Here is the rub: They want a ~2MW version...   Not 20MW...

The diameter of core cannot be shrunk.  Its length can; by ~half getting a ~10MW version.  See the problem with the small core is that the center is hot but, temperature quickly falls off due to lack of nuclear fission + fluid flow through core and with a 1ft diameter/8ft core I was working on did not come up to true nuclear fission until ~half its length up its core, thus allowing at least SOME throttling of power output and why I am stating, that Technically you can go smaller length core, but... you lose power regulation and why I believe the Russian 40MW core uses much higher enriched fuels of Uranium if not Plutonium(allows different core technologies as well which is an even BIGGER consideration for length of life).  Even our version was using HIGHER enriched Uranium content to make it work.  We barely squeaked under the NRC's threshold and lasted ~2 yrs before refueling required(since most of our fuel was never burned to begin with, most of the rods could just have their segments moved around).

PS: Take what I say with a big grain of salt, as I am NOT a nuclear physicist, but rather mechanical engineer doing the heat transfer, fluid mechanics, structure, safety etc. We worked for years on this(Had all the testing done except the final version--> Had electric version), but early 2000's was well... bad time and still is a bad time in the USA to try and ... MODERNIZE our infrastructure.  I have heard tell, that cancer patients do like living longer and the only place to obtain those radioisotopes is a nuclear reactor. 

PPS: I inherited the pressure reactor failure valving/plug safety mech.  It was brutally simple and a genius design as far as I am concerned and it is a CRIME that this is built into all existing nuclear reactors on a MUCH larger scale today. 

[ronwagn + 6,290]

39 minutes ago, footeab@yahoo.com said:

Uh, first: I screwed up: I wrote 100MW above, Ours was 20MW; the one I worked on.  The 100MW was the Westinghouse version we always used to compare ours.  😯

The small nuclear modular reactors, I believe ALL of them, at least ALL of them when I was working on them required positive working pressure, but not too much positive pressure.  In other words had 2 different valves.  Either failed, whole thing scrams.  Too low of a pressure say to a leak, would blow the low pressure valve and the mechanism HOLDING the fuel rods from the TOP, AND the bottom plug up(bottom seal/refueling entrance) and IN place would FALL out the bottom of the reactor.  Too High of a pressure, and same thing.  Too hot of a temperature(pool they were operating in drained)... the bottom plug would melt out and the melted slag would descend into an emergency tube/underground box filled with boron splitting up the reactor killing the fission.  Hrmm, A picture would be worth a 1000 words here, maybe 10k words😎

Now the version I was working on(ORL/INL/PNL) could get stuck running at 100%, without the turbine operational, and the heat conduction of its eggshell was sufficient, if it was submersed in a pool of water, to never melt down. 

The biggest problem we had was to meet the above criteria, plus many more, we required a reactor that was ~65 feet long by 14 feet wide for 20MW @ 18% efficiency conversion(fuel burn was astronomical), and the core size was held at approximately ~1 ft in diameter by ~8ft long core, had 4" thick stainless steel walls, and had to be moved by a very specialized railroad car.  This size was required to keep the thermal safety properties and the core diameter/length.  The 65 feet was required to create a thermal chimney out of the core from which a heat exchanger can pull the heat without being destroyed by nuclear bombardment and hold all the safety structures etc.  AKA NO PUMPS required to cool it.  No external power required to run it.  No sensors requiring active monitoring.  No human required.  No computer required.  100% PASSIVE. 

Here is the rub: They want a ~2MW version...   Not 20MW...

The diameter of core cannot be shrunk.  Its length can; by ~half getting a ~10MW version.  See the problem with the small core is that the center is hot but, temperature quickly falls off due to lack of nuclear fission + fluid flow through core and with a 1ft diameter/8ft core I was working on did not come up to true nuclear fission until ~half its length up its core, thus allowing at least SOME throttling of power output and why I am stating, that Technically you can go smaller length core, but... you lose power regulation and why I believe the Russian 40MW core uses much higher enriched fuels of Uranium if not Plutonium(allows different core technologies as well which is an even BIGGER consideration for length of life).  Even our version was using HIGHER enriched Uranium content to make it work.  We barely squeaked under the NRC's threshold and lasted ~2 yrs before refueling required(since most of our fuel was never burned to begin with, most of the rods could just have their segments moved around).

PS: Take what I say with a big grain of salt, as I am NOT a nuclear physicist, but rather mechanical engineer doing the heat transfer, fluid mechanics, structure, safety etc. We worked for years on this(Had all the testing done except the final version--> Had electric version), but early 2000's was well... bad time and still is a bad time in the USA to try and ... MODERNIZE our infrastructure.  I have heard tell, that cancer patients do like living longer and the only place to obtain those radioisotopes is a nuclear reactor. 

PPS: I inherited the pressure reactor failure valving/plug safety mech.  It was brutally simple and a genius design as far as I am concerned and it is a CRIME that this is built into all existing nuclear reactors on a MUCH larger scale today. 

Did you mean to say itis a CRIME that it is NOT built into all existing nuclear reactors...?

[footeab@yahoo.com + 2,131]

10 minutes ago, ronwagn said:

Did you mean to say itis a CRIME that it is NOT built into all existing nuclear reactors...?

Ah, dyslexia strikes again. 

I have no idea how it works, but switching letters, leaving out words... yup.  That is me.  Drives me insane and those I have to talk to.  In my mind I say one thing, but my tongue does not....  Works that way with my fingers as well. 

[ronwagn + 6,290]

1 hour ago, footeab@yahoo.com said:

Ah, dyslexia strikes again. 

I have no idea how it works, but switching letters, leaving out words... yup.  That is me.  Drives me insane and those I have to talk to.  In my mind I say one thing, but my tongue does not....  Works that way with my fingers as well. 

I just made a simple math error that Oro caught me on. You are head and shoulders above me in engineering and math. 

[footeab@yahoo.com + 2,131]

PS: WHY military wants this.... Currently a very large portion of military revolves around airfields for logistics especially with the corralary fuel logistics string being horrifically vulnerable.  These are known locations and nothing but a giant target that is easily eliminated.  Defense of said infrastructure be it by land or by sea is currently ~~~ effectively impossible.   IF, LASERS become viable defensive weapons(jury is still out), then a giant power source is required.  Ships are likewise going electric drive.  Now throw on additional electric load of defensive fire and the preminent link in having a functioning military is POWER and small nuclear reactors which require ZERO human hands at the wheel and emergency scram themselves and are modular are optimal.  If on land, you just dig a giant ass hole, dump them in, run cables out.... now cooling on the other hand, just requires moving a lot of air, and now you have "free" power so... not a problem.  Electric motors are near indestructible so...

[BenFranklin'sSpectacles + 762]

On 3/9/2020 at 9:53 PM, ronwagn said:

https://www.defensenews.com/smr/nuclear-arsenal/2020/03/09/pentagon-to-award-mobile-nuclear-reactor-contracts-this-week/

What could possibly go wrong? Maybe a rocket propelled grenade, mortar, IED, drone strike? RCW

 

On 3/10/2020 at 2:50 AM, Marcin2 said:

Ron, it shows how creative and smart MIC can be in new proposals to waste taxpayers money. Fantastic people , if their brain power could be harnessed for the benefit of the nation.

The story is good cause Russians already developed small nuclear reactors 40 MW ? for usage as floating power plants for towns in Arctic.

Rolls-Royce was talking recently about 225/450 reactors.

Alternative for 40 MW floating power plant is crude oil generator together with 50,000 tons of fuel for 1 year of operations.

Makes sense in Russia not in US.

And should be floating or very  dangerous and very costly exercise.

They also could just change designs from small French nuclear subs reactors.

Actually there was small nuclear reactor on US military submersible vessel - should be mobile/ portable cause was small.

 

On 3/11/2020 at 4:53 PM, footeab@yahoo.com said:

PS: WHY military wants this.... Currently a very large portion of military revolves around airfields for logistics especially with the corralary fuel logistics string being horrifically vulnerable.  These are known locations and nothing but a giant target that is easily eliminated.  Defense of said infrastructure be it by land or by sea is currently ~~~ effectively impossible.   IF, LASERS become viable defensive weapons(jury is still out), then a giant power source is required.  Ships are likewise going electric drive.  Now throw on additional electric load of defensive fire and the preminent link in having a functioning military is POWER and small nuclear reactors which require ZERO human hands at the wheel and emergency scram themselves and are modular are optimal.  If on land, you just dig a giant ass hole, dump them in, run cables out.... now cooling on the other hand, just requires moving a lot of air, and now you have "free" power so... not a problem.  Electric motors are near indestructible so...

The concept sounds scary because we've all been conditioned to fear nuclear, but honestly, nuclear fallout is no worse than the other crap the US military exposes troops to. 

First, fallout is unlikely to be significant even if the reactor is hit.  Atmospheric reactor designs - such as liquid sodium or fluoride salt - don't explode like pressurized reactors.  Without all that steam energy to sling mass everywhere, the radioactivity is more contained.  Not contained enough for civilian purposes, but possibly enough for military purposes. 

It's unlikely these will be deployed to forward bases exposed to attack either.  Instead, they'll power bases reachable only by strategic bombers and ballistic missiles.  We'll be able to defend against that. 

There's also the issue of targeting.  Aiming a ballistic missile over a couple hundred miles is difficult.  Aiming it over a thousand miles or more is a remarkable achievement.  E.g. the US built 10 megaton thermonuclear warheads because we needed the blast radius to be larger than the probable landing zone radius.  Our targeting technology has since progressed, but few of our opponents can match that capability. 

Assuming you did place these close enough to be attacked, the risk is still minimal.  These will be placed inside bunkers.  THICK bunkers.  Assuming you can achieve the necessary direct hit, it's not likely you'll penetrate the bunker.  To give you an idea how difficult it is to penetrate bunkers, here's a jet crashing into a wall at 500mph:

 

So yes, this sounds scary.  No, the risk is not as high as it seems.  Attacking one of these is a non-trivial problem. 

[ronwagn + 6,290]

6 hours ago, BenFranklin'sSpectacles said:

 

 

The concept sounds scary because we've all been conditioned to fear nuclear, but honestly, nuclear fallout is no worse than the other crap the US military exposes troops to. 

First, fallout is unlikely to be significant even if the reactor is hit.  Atmospheric reactor designs - such as liquid sodium or fluoride salt - don't explode like pressurized reactors.  Without all that steam energy to sling mass everywhere, the radioactivity is more contained.  Not contained enough for civilian purposes, but possibly enough for military purposes. 

It's unlikely these will be deployed to forward bases exposed to attack either.  Instead, they'll power bases reachable only by strategic bombers and ballistic missiles.  We'll be able to defend against that. 

There's also the issue of targeting.  Aiming a ballistic missile over a couple hundred miles is difficult.  Aiming it over a thousand miles or more is a remarkable achievement.  E.g. the US built 10 megaton thermonuclear warheads because we needed the blast radius to be larger than the probable landing zone radius.  Our targeting technology has since progressed, but few of our opponents can match that capability. 

Assuming you did place these close enough to be attacked, the risk is still minimal.  These will be placed inside bunkers.  THICK bunkers.  Assuming you can achieve the necessary direct hit, it's not likely you'll penetrate the bunker.  To give you an idea how difficult it is to penetrate bunkers, here's a jet crashing into a wall at 500mph:

 

So yes, this sounds scary.  No, the risk is not as high as it seems.  Attacking one of these is a non-trivial problem. 

The bunkers are not mentioned in the story. It takes time to set up a bunker and they must  be transported to the bunker. So that is an ideal time to attack them. An enemy would not be slamming a plane into them, it would be a special bomb or missile designed to penetrate. 

Edited March 18, 2020 by ronwagn
addition

[George8944 + 128]

We have a company here in Ohio that makes portable nukes.  They fly under the radar for obvious reasons.   They are one of my customers.   I wil forward this article to them tomorrow.  I'm sure they are alread in touch.