Naval Nuclear Reactor Discussion

[sdmuleman]

Removal of one turret (blasphemy, I know) would make room for a goodly number or missiles, I would think.

Get rid of that aft turret…you could have drone rails to either side maybe?

Removing a turret, especially the single aft one would have pretty significant impacts on stability, trim and hull stresses. Also would then be constrained by size and shape of the barbette for whatever went in, and the mazarines and powder handling rooms are likewise difficult to repurpose. Also, the barbette armor probably isn't usable structurally (likely can't effectively weld to it or drill it), so there's some weird structural support challenges. Likely far more work than it's worth.

All very interesting for discussion but, how would she have managed with the original engines and machinery? Is this the sort of thing that makes more sense with new propulsion? Nuclear even? This would (Shirley, I know) allow more of a free hand with deck and upperwork mods.

This would of course cost half a body or more let alone a few legs.

Essentially impossible to backfit a warship to nuclear power for the same reasons it's essentially impossible to remove the reactor - the reactor is very deeply integrated into the ship structure to the degree it's literally designed and built around the reactor vessel. Conceptually you'd have to build an entirely new engineering plant, including hull structure and somehow mate it to rest of the ship. While not technically impossible, the practical difficulties are rather mind boggling, and it would also certainly be far more difficult than building a new ship from scratch.

 

[Dilandu]

Essentially impossible to backfit a warship to nuclear power for the same reasons it's essentially impossible to remove the reactor - the reactor is very deeply integrated into the ship structure to the degree it's literally designed and built around the reactor vessel. Conceptually you'd have to build an entirely new engineering plant, including hull structure and somehow mate it to rest of the ship. While not technically impossible, the practical difficulties are rather mind boggling, and it would also certainly be far more difficult than building a new ship from scratch.

Well, if reactor is relatively compact, and made as single integrated module, it's possible. USSR backfitted one of diesel-electric submarine with a very small nuclear reactor in streamlined external module under rear hull. The idea was, that it would not directly power the drive (it was too low-power for that) but constantly recharge batteries without the need to surface or snorkel.

 

[publiusr]

Well, could a Ford type reactor fit in an IOWA turret well? About the same mass--maybe scale it down some more.

It wouldn't even need be part of the drive train--just hook it up to DEWs/ECW.

 

[Vepr157]

Well, could a Ford type reactor fit in an IOWA turret well? About the same mass--maybe scale it down some more.

Highly doubtful. The D2G plant, which was considerably smaller and less powerful, required a reactor compartment 31 feet in diameter, not much narrower than an Iowa's turret.

Even if the primary plant itself would physically fit, you still would need the entire secondary system, which takes up more volume than the primary plant. If you could somehow figure out a way to get the steam lines to the existing main engines and turbine generators, you would have to reblade all of the turbines to work with the different steam conditions (the reactor could not produce superheated steam). You'd probably have to gut a lot of the existing secondary system; levels of chloride in feedwater that might be tolerable for a conventional steam plant would be unacceptable for a naval reactor plant.

So there's no practical way to provide any meaningful power to an Iowa via nuclear propulsion. You would have to gut the ship, and it would almost certainly be faster and cheaper just to build a new ship.

 

[sdmuleman]

Well, if reactor is relatively compact, and made as single integrated module, it's possible. USSR backfitted one of diesel-electric submarine with a very small nuclear reactor in streamlined external module under rear hull. The idea was, that it would not directly power the drive (it was too low-power for that) but constantly recharge batteries without the need to surface or snorkel.

Possible perhaps. Practical, unlikely. Small reactor is something of an oxymoron because things like shielding don't scale linearly. As an example, something like 2/3 of NR-1 (12x96' pressure hull) was taken up by the reactor plant, and for all of that volume it makes enough power to run life support and move at <5 kts. I would be inclined to imagine the 'small streamlined module' looked something like a rather large tumor, probably cause more power loss in resistance than it produced, and likely resulted in some interesting handling issues underwater. Not to mention given the Soviet idea of radiation health essentially boils down to if you drink enough vodka you don't notice the radiation sickness, I'd recommend avoiding service in that boat.

Highly doubtful. The D2G plant, which was considerably smaller and less powerful, required a reactor compartment 31 feet in diameter, not much narrower than an Iowa's turret.

Even if the primary plant itself would physically fit, you still would need the entire secondary system, which takes up more volume than the primary plant. If you could somehow figure out a way to get the steam lines to the existing main engines and turbine generators, you would have to reblade all of the turbines to work with the different steam conditions (the reactor could not produce superheated steam). You'd probably have to gut a lot of the existing secondary system; levels of chloride in feedwater that might be tolerable for a conventional steam plant would be unacceptable for a naval reactor plant.

So there's no practical way to provide any meaningful power to an Iowa via nuclear propulsion. You would have to gut the ship, and it would almost certainly be faster and cheaper just to build a new ship.

This. An A4W reactor vessel would probably fit in the barbette. The rest of the primary loops wouldn't, and the shielding, secondary plant, etc. etc. most certainly would not. The propulsion plant on a carrier takes up a similar amount of space to the existing plant on a BB. There's a heck of a lot of bits you need, some of them quite large. Also lots of integration. Things that drain tanks for potentially radioactive liquid - you don't just stick that in a random inner bottom tank.

Good point about turbines - didn't think of that but you're right.

 

[Dilandu]

Not to mention given the Soviet idea of radiation health essentially boils down to if you drink enough vodka you don't notice the radiation sickness, I'd recommend avoiding service in that boat.

Sigh. And now could you re-read my post, please? The reactor was in external shielded capsule.

 

[Vepr157]

The issue with something like that used for the Project 651E is that the power is so low, just 600 kW. For comparison, an Iowa had eight 1,250 kW turbine generators. External (seawater) shielding is only really practical for submarines.

 

[sdmuleman]

Sigh. And now could you re-read my post, please? The reactor was in external shielded capsule.

Yes, I read that bit. Unless it was in a free-floating capsule or something equally absurd it's going to be attached to the main hull. And yes, it was shielded.... to the Soviet standard of shielding. Hence my point. Very likely a similar setup meeting western standards for shielding would be somewhat larger and heavier than what they used.

 

[Scott Kenny]

Yes, I read that bit. Unless it was in a free-floating capsule or something equally absurd it's going to be attached to the main hull. And yes, it was shielded.... to the Soviet standard of shielding. Hence my point. Very likely a similar setup meeting western standards for shielding would be somewhat larger and heavier than what they used.

It'd only have major shielding in the directions where crew normally were.

Otherwise they'd just leave the shielding out entirely. If we had divers over the side when the reactor was running, we had to mark the edges of the reactor compartment so the divers would not linger there.

 

[sdmuleman]

The issue with something like that used for the Project 651E is that the power is so low, just 600 kW. For comparison, an Iowa had eight 1,250 kW turbine generators. External (seawater) shielding is only really practical for submarines.

Note as well that reactors are commonly rated by thermal power, which is typically about 4 times the electrical power you can generate (and that usually doesn't include hotel load to run the plant itself, typically around 10% of gross power). Wouldn't be surprised if it's 600 kW thermal, i.e. about 100-150 kW usable electrical output.

 

[Dilandu]

to the Soviet standard of shielding.

Well, considering that American standards of radiation protection were "hey, let's send troops without so much as gas masks through the ground zero of nuclear blast"... American submarine reactors were better basically because of Hyman Rickover's adamant position of "safety above all", not because USN in general particularly cared.

 

[Vepr157]

Note as well that reactors are commonly rated by thermal power, which is typically about 4 times the electrical power you can generate (and that usually doesn't include hotel load to run the plant itself, typically around 10% of gross power). Wouldn't be surprised if it's 600 kW thermal, i.e. about 100-150 kW usable electrical output.

No, I was quoting the power of the turbine generator. The thermal power was 5 MW.

 

[Vepr157]

to the Soviet standard of shielding.

What you are suggesting is a common misconception. The Soviets certainly had several nuclear accidents, but they were not due to the shielding, which was perfectly adequate. The myth that the Soviets skimped on shielding is primarily due to the western underestimation of the November SSN's top speed: 30 knots compared with the Nautilus' 23 knots. Some suggested that the Soviets had achieved such high power density by reducing shielding. What they did not realize is that the November had two reactors, each with more power than the Nautilus' single reactor plant. Again, this is not to say that the Soviets did not have issues with their reactors; they absolutely did. But it was not the fault of the shielding.

 

[sdmuleman]

Well, considering that American standards of radiation protection were "hey, let's send troops without so much as gas masks through the ground zero of nuclear blast"... American submarine reactors were better basically because of Hyman Rickover's adamant position of "safety above all", not because USN in general particularly cared.

The objective facts say something rather different. The Manhattan project as far back as 1942 had a fairly rigorous radiation health program, and this continued through various power and weapons programs. Yes, some of the early atomic tests lacked the protective measured we would consider common sense today, but that doesn't equate to a lack of protection/concern. Further, when you look at actual doses / dose estimates instead of the overly dramatic talking point, the exposure of those folks wasn't in the grand scheme of things all that significant. (note - I'm NOT saying it was appropriate, rather that in pretty much all cases the exposure was less than the yearly allowable radiation worker dose rate).

In contrast, the Soviet nuclear weapons program had multiple years in which the average worker dose for a specific facility was ~100 rem, including one in which 1.8% of the workforce received over 400 rem in a year. Granted, this was in the early 50's, and by the 70's doses are much lower, but still significantly higher than in the west, and at no point was there anywhere near that level of intentional exposure anywhere in the west.

Point isn't to shame Russia, but rather to point out that at least in some areas there was a significantly different perspective on safe exposure.

Source for above figures is this book: https://www.amazon.com/Making-Russian-Bomb-Stalin-Yeltsin/dp/0813323282

What you are suggesting is a common misconception. The Soviets certainly had several nuclear accidents, but they were not due to the shielding, which was perfectly adequate. The myth that the Soviets skimped on shielding is primarily due to the western underestimation of the November SSN's top speed: 30 knots compared with the Nautilus' 23 knots. Some suggested that the Soviets had achieved such high power density by reducing shielding. What they did not realize is that the November had two reactors, each with more power than the Nautilus' single reactor plant. Again, this is not to say that the Soviets did not have issues with their reactors; they absolutely did. But it was not the fault of the shielding.

My understanding was that Soviet submarines pretty much all had higher allowable Sailor dose rates and less rigorous shielding requirements. I will acknowledge that it's not something I have researched in detail. Do you have any recommendations for English language sources on soviet naval radiation health/exposure?

 

[Vepr157]

My understanding was that Soviet submarines pretty much all had higher allowable Sailor dose rates and less rigorous shielding requirements. I will acknowledge that it's not something I have researched in detail. Do you have any recommendations for English language sources on soviet naval radiation health/exposure?

I don't know of any good sources in English on Russian submarines except Cold War Submarines by Polmar and Moore. I would have to do some looking into the Russian-language books I have; I am not aware of any that cover that specific topic, but I have never looked.

Even the Alfa, which had engineering spaces that were not continuously-manned, had an extensive shield with thick layers of lead, polyethylene, water, concrete, and steel. If the Soviets had more lax requirements, it was not because of the shield.

 

[TJDougherty01]

This may help with the discussion.

 

[publiusr]

I wasn't thinking of a reactor to power the ship---a pebble bed in place of a turret plugged to a DEW was my thinking. Front turrets keep the guns--smokestack back all high tech.

Ship gets made a museum piece again--put the old turret(s) in and have the reactor-laser turrets like Aegis Ashore.

The goal would be to keep each socket piece has self-maintained as possible...lasering drones to protect a carrier group

 

[WatcherZero]

Soviet shielding was lower but the compartments were designed to be more automated with crew only accessing them for repair, the engineering stations were on the bridge.

 

[Vepr157]

Soviet shielding was lower but the compartments were designed to be more automated with crew only accessing them for repair, the engineering stations were on the bridge.

As we have been discussing, that misconception is not supported by Russian literature on the subject. Concentrating the entire watch section in the control room was only the case for the Project 705 (Alfa) SSN. And in the Russian literature on the Alfa, I can find no reference to any relaxation of shield requirements. The designers went to great efforts in designing the reactor shield for that submarine.

 

[WatcherZero]

Funnily enough the Alfa using the Lead-Bismuth reactor is noted for requiring less shielding than water cooled designs, as if the reactor was allowed to cool into a solid mass the lead in the core provided adequate shielding for the crew such that extra shielding wasn't required in the event of an emergency. They needed a steady steam supply above 257 fahrenheit for the core to remain molten, if they boiled dry the core would cool, so they were inherently fail-safe (though resulted in Bricking as they couldn't be restarted). They did produce a large amount of Po210 isotopes though and were noted as suffering from severe corrosion problems. The core also had to be supplied with steam during the fuelling process.

 

[Scott Kenny]

I wasn't thinking of a reactor to power the ship---a pebble bed in place of a turret plugged to a DEW was my thinking. Front turrets keep the guns--smokestack back all high tech.

Ship gets made a museum piece again--put the old turret(s) in and have the reactor-laser turrets like Aegis Ashore.

The goal would be to keep each socket piece has self-maintained as possible...lasering drones to protect a carrier group

That... May be doable.

I'm not sure about the size of a pebble bed reactor that can crank out a couple megawatts for lasers plural.

 

[publiusr]

That... May be doable.

I'm not sure about the size of a pebble bed reactor that can crank out a couple megawatts for lasers plural.

A generator...hell, a 777 engine.. something...Capsules, S.S. UNITED STATES, MiGs--lots of old tech is on its way out...I'd like to see *something* from the past live again.

 

[Airbus A340]

Does anyone know what kind of reactor the Chinese are using in their nuclear Stirling driven sub?

 

[Vepr157]

Does anyone know what kind of reactor the Chinese are using in their nuclear Stirling driven sub?

Do we even know if they are building such a submarine? I was under the impression that it they merely may or may not be building a small nuclear submarine.