Help Needed on Russian Sub re-building capability

On the debate of Liquid Metal Reactor , I have found few more reason from other forum,
Thought It would be good to share

Thanks to Shankar From BRF:

extreme reactivity of sodium with water is always a clear and present danger that includes moisture in air that you breath out within the close confines of a sub .In a land based reactor it is protected by heavy argon gas more commonly called as cover gas which layers the liquid metal reactor and prevents the atmospheric moisture from getting in and reacting with hot liquid sodium. Prob lem is even the cover gas can get contaminated by nuclear reactio products like Xenon which are radioactive but have a short half life of about 7 days or so. In a land based reactor these gases can be held in cryogenic liquid form or adsorbed form till the radioactivity level is down to acceptable . Similar treatment of radio active off gases inside a submarine is diffcult and a further penalty on space and payload .

The russian alfa class used a different type of liquid metal coolant namely lead -bismuth which had to be kept at 125 celcius plus no matter what .The reactors had to be kept running alwys since providing power and steam from outside when in harbour to keep the liquid metal coolant operational was too trouble some .In fact one of the reactors was a lost case since the fuel rods got stuck in fozen liquid metal coolant .

A total of 8 alfa class liquid metal cooled fast reactor powered submarines were built and assigned to northern fleet out of which 7 are confirmed de commssioned and the remaining one may be still operational but not confirmed . Refueeling even by part is not possible with liquid metal cooled reactors and thats why they are one lift time fuelling type with a rated reactor life of 70 years .

K-27 a november class boat was modified to try out the newly developed lquid metal cooled reactors for alpha class . During sea trials reactor power was totally lost causing radioactive gases to leak into operating area .9 crews were killed . The submarine K-27 was removed from service .

All this with first generation liquid metal cooled reactor using lead and bismuth now we use in our fast breeder reactor liquid sodium which has much higher operating temperature and many times more reactive .

Thanks GarryB , Neptune for the reply.

Another question , If I have 2 small 90 MW PWR and a single 180MW reactor and my subs requires a total power of say 150 MW.

Will there be any specific reason or advantage of using the two 90 Mw reactor over a single 180 Mw Reactor

I always thought a better use for Typhoons would be as a mothership for DSRVs. Since the Indias were both withdrawn from service I have only heard of one vessel taking on the role… a Delta III. Perhaps a sub the size of the Typhoon could be fitted with a few articulated arms that would allow it to land on the sea bed next to a striken sub and reach over and attach a boom to the escape hatch of the sub so the crew could escape through the hollow tube into the Typhoon down to depths of 300m or so. Some DSRVs could be carried for rescues down to crush depth (below that you just recover bodies so rescue vehicles have limited use there). The Typhoon hull is large enough for decompression tanks for a full sub crew and it is fast enough to get to most places very rapidly, though I’d want at least two, and preferably three of them.

Basically not, as it would bring at least some profit by transporting these goods, in either giving those people in Siberia what they need or giving some money, instead of only taking more money by arming them with useless weapons and sailing around without giving ANY money back. So “better use” is a very relative thing given that half the world is very unlikely to attack Russia at the moment (and that they have enough SSBNs remaining to do that job) and that those people really need those potatoes (well after the conversion she was meant to transport ore for Norilsk)

The Typhoon conversion looks good and well thought off , But the Russian can make much better use of Typhoon by arming them with Bulavas , Rather then use it as a platform to transport Potatoes and oranges under the ice to Siberria , Gosh I hate people degrading the once mighty Typhoon , A single sub then had the capability to destroy half of the world.

Now they want to transport Potatoes under the ice 😀

here is a drawing of the cargo-typhoon from the site of Rubin,
the link will get you to the general explanation:
http://www.ckb-rubin.ru/eng/project/otherp/uwaters/index.htm


Very interesting on this drawing is that you can actually see her very tiny propellors on the lower side of the aft hull, these are really present on the submarines at the moment too. For slow speed manoeuvering.
The strange bow shape is done for the ice breaker capacity on the surface.

Very interesting answeres. Is it possible to see a very comprensive article on Russian attempts on converting a non nuke to nuke sub? I know its difficult to find it, I hope i get one such article.

Thanks all..

They have used a Typhoon once with missile tubes filled with potatoes, to transport them to SIberia. Afterwards the idea of a submerged Bulk carrier came. Just removing the missile tubes and use the entire forward space as cargo room. Too costly, nuclear reactors can’t be profitable and as Norilsk, the company who wanted to convert this Typhoon is a company with profit on its mind, it was soon abandoned.
A nuclear ice breaker when used properly can do several transports, while instead you would require many more nuclear powered submarine to run that same route. The idea was going up one of the large rivers in Siberia, then dive below the ice in the arctic and go to Murmansk, unload there in a “normal” ship and return to the river. (I think it was the Yennisei or Lena river).

I should add that there were several suggested modifications of various types of Soviet subs including altering Typhoons into large cargo ships for use under the arctic Ice. There was also the alteration of a Delta class SSBN ( a III vessel I think) into the role previously carried out by the Lenok (India class) with a couple of DSRVs.

I would think that the most verstile subs for modification would be the ex SSBNs as they are large and have lots of free space once all the SLBMs are removed.

Thanks Garry , If that is the case what happens to the Fast Breeder Reactor which uses Liquid Sodium Metal as coolant , dont they turn of the system any time for maintainence etc .

They shut down the reactor no problem, but they need an auxiliary heating system to keep the coolant liquid. The amount of power required is not enormous but at sea you’d run your batteries flat very rapidly to keep the coolant liquid while you had the reactor shut down. For this reason they had to leave the reactor on all the time… they even left it on while in port. It is my understanding that at least one Alpha had its reactor replaced with a more conventional reactor because of these problems.

One of the major problems of Alpha was indeed that you couldn’t turn it off, not even in port. They sometimes did put it off and used some land based equipment to keep the coolant running (that is only in port of course). This extra equipment was very expensive and certainly when it can only be used for the small number of Alpha’s.
PWRs are always heavy, the reactor itself, but also the shielding. You could also use a diesel tank as only shielding in front of your reactor, but I don’t think they called those stupid Novembers “Cancer Incubators” for nothing… The Foxtrot would become the same due to her small size and limited weight allowance. Of course one could remove the aft tubes and torpedoes to save some weight, but again the sheer moments and forces would be the major issue preventing this.

How about a single 90 MW PWR in a foxtrot?

The problem is you can’t turn it off… if you do the metal hardens and you need to replace all of the pipes and hardened reactor coolant… in other words it is like when you turn off a concrete mixer full of concrete… it isn’t worth chipping out the hard cement, you replace the whole mixer.
They did have an back up heating system but if that failed… replace the entire reactor… not cheap.

Thanks Garry , If that is the case what happens to the Fast Breeder Reactor which uses Liquid Sodium Metal as coolant , dont they turn of the system any time for maintainence etc .

What I read with russian case was the repeated leaks of radioactive coolant in the reactor leading to safety issue on the subs, Hence they didnt went ahead with it.

What was the trouble ??? It was a low weight , high density reactor with liquid sodium as the coolant , it was the ideal reactor for a sub , unfortunately for soviet it turned to be expensive and couldnt solve its problem.

The problem is you can’t turn it off… if you do the metal hardens and you need to replace all of the pipes and hardened reactor coolant… in other words it is like when you turn off a concrete mixer full of concrete… it isn’t worth chipping out the hard cement, you replace the whole mixer.

They did have an back up heating system but if that failed… replace the entire reactor… not cheap.

The Lira is called Alpha by the west, they all had trouble with the reactors, the liquified metal ones

What was the trouble ??? It was a low weight , high density reactor with liquid sodium as the coolant , it was the ideal reactor for a sub , unfortunately for soviet it turned to be expensive and couldnt solve its problem.

The Lira is called Alpha by the west, they all had trouble with the reactors, the liquified metal ones. The reactors were cut out and replaced by normal PWRs. But then again, these boats were built as SSNs from the start.

Is it possible to get more technical details on the projects? I will also google for the details in english. Thanks Snake, Neptune and Unicorn….

One of Juliets was equipped with auxulary nuclear reactor, although it was not intended to rebuild the older boats. I believe that one of Liras also suffered the cutting out and replacement of reactor compartment, as did K-19.

Yeah, someone must have lost his mind. Ever thought about shielding? If you put a reactor in a Foxtrot, that’ll teach them one thing, how to get cancer. And that would be the only thing to learn from that, apart from it being a very stupid idea.
Ever thought about the weight of such a configuration? If you put that in a weak Foxtrot hull, near its center of gravity, all the thing will do is break. Huge buoyancy on the far sides of the core, with a relatively low weight, while the buoyancy on the part of the reactor will be low compared to the weight. That will cause a huge amount of sheer forces and bending moments, causing a break up. It’s not built for it and hence it can not take it. Too few strengthening parts etc. If you would really really really want it, it could succeed, but after all the reinforcements and lengthening needed, it probably can’t be called Foxtrot anymore. The displacement of the sub would rise with a huge amount and hence the size would have to follow, lengthening, possibly beam change etc.

Well few things can be achieved for a non-nuclear navy. It can help understanding nuclear reactor mating, operational experience and validating technologies at a cost effective price.