Project 955: Borei class SSBN

US has the most potent nuclear submarine building capability in the world by a long shot right now. Russia is in line with the other builders, US is the one outlier.
They don't make diseal boats, but they make larger nuclear submarines faster!

Perhaps because they have always been fully funded and never had a 15 year break when even minor repairs were not funded let alone no major vessels were laid down...

The real question is WTF would be the point of making 20 nuke subs a year.... even the US with its global empire to maintain and countries to attack within an hour or what ever their goal is at the moment doesn't need as many subs as it has or is making... what cute cuddly prize would Russia get if it wasted the money and tried to out produce the US in subs?

Of course despite your low opinion of conventional subs I would argue that they are actually rather more useful and cost effective and EXPORTABLE.

The new Lada-M class have the sonar and equipment previously only seen on nuclear attack subs. With new batteries and AIP they will have all the best attributes of a nuke but without the top speed... when they get its problems sorted out and into production I suspect they will sell very well.

GarryB wrote:
Of course despite your low opinion of conventional subs I would argue that they are actually rather more useful and cost effective and EXPORTABLE.

Garry , Borei will also be using OK 650 reactor right ...?

What's the weight of the OK 650 reactor ?

RTN wrote:

Garry , Borei will also be using OK 650 reactor right ...?

What's the weight of the OK 650 reactor ?

This information is kinda rare.. I'm also looking for it.

Nonetheless, you can try estimating them based from following table :



Borei is using OK-650 with OK-9 GTZA (Turbine) With around 50000 Shaft horse power or 37284 Kw. The latest OK-650 as far as i know is a monoblock construction where steam generator is "unified" With the reactor, making it more compact. Thus we can assume specific weight of 21 Kg/Kw

Thus the reactor along with its steam generator would weigh 37284*21=782964 Kg or some 782 ton discounting the shield tank and foundation.

If we included those parts, assuming specific weight of 7 Kg/Kw the weight of the foundation and shield tank would be 7*37284=260988 or 261 ton.

Bring total weight of 1043 Ton.

Stealthflanker wrote:
This information is kinda rare.. I'm also looking for it.

Nonetheless, you can try estimating them based from following table :

Thanks Stealthflanker . I kinda did the math on this based on the numbers that you provided . It seems Russian reactors for submarines are quite heavy compared to US ones . Not sure of the reason though .

First, the power generation you mentioned in the kilowatt range for actual unmanned spacecraft is probably from a thermoelectric generator as opposed to a fission reactor.  

A thermoelectric generator converts the heat generated from natural radioactive decay into electric power.  Due to design considerations it is not practical for thermoelectric generators to be large enough to produce more than about a kilowatt of electricity.  Based on pure physics, however, here is the thermoelectric generator calculation.

Plutonium is often used in space applications because of its long half-life.  So, if a space craft is on a decades-long mission, A Pu power source should be able to function continuously.  The downside of plutonium is that it is extremely heavy.  Considering plutonium-238 for the moment, its specific power is 0.56 Watts/gm due to natural radioactive decay.  So, to generate 1 kW, we need 1000*0.56 gm = 560 gm or 0.56 kg.  This is thermal energy due to radioactive decay.  The thermoelectric generator which converts the thermal energy to electric energy has an efficiency of only a few percent.  For our example, let's assume a 5% conversion efficiency.  Then, the 0.56 kg will generate 0.05*1000 Watts = 50 Watts electric power, or, we can get 89 Watts per kilogram.  For 1 Kw, our mass is 11 Kg.  For  1 MW, our mass is 11,000 kg.

Now, onto a more practical means for generation 1 MW of power using a Plutonium fission reaction.  

To calculate the mass required to obtain a certain power level, we have to know the neutron flux and the fission cross-section.  Let’s assume the flux is 1E14 neutron/cm2/sec, the cross section for fast fission of Pu-239 is about 2 barns (2E-24 cm2), the energy release per fission is 204 MeV, and the Pu-239 number density is 4.939E22 atoms/cm3.  Then the power is

P = flux * number density * cross section * Mev per fission * 1.602E-13 Watt/MeV
P = 1E14 * 4.939E22 * 2E-24  * 204  * 1.602E-13  = 323 W/cm3

So, for 1 MW, we need  1E6/323 = 3100 cm3.  Given a density of 19.6 gm/cm3, this is 19.6*3100 = 60,760 gm or 60.76 kg.  

The next question to ask is: how long do you want to sustain this reaction?  In other words, what is the total energy output?

For example, a Watt is one Joule per second.  So, to sustain a 1 MW reaction for 1 year, the total energy is 1E6 J/s * 3.15E7 s/year = 3.15E13 J

For Pu-239, we have 204 Mev per fission and we have 6.023E23./239 = 2.52E21 atoms/gm.  So, the energy release per gram is 2.52E21 * 204 Mev/fission * 1.602E-13 J/Mev = 8.24E10 J/gm.

Therefore, to sustain 1 MW for 1 year, we will use 3.15E13 J / 8.24E10 J/gm = 382 gm of Pu-239 or 0.382 kg.  This is only a small fraction of the total 60.76 kg needed for the fission reaction.

Finally, this is thermal energy.  Our current light water reactors have about a 35% efficiency for conversion to electric power.  So, you can take these numbers and essentially multiply by 3 to get a rough answer for the total Pu-239 needed: 3 x 60.76 = 182 kg.  Rounding up, you would need roughly 200 kg for a long term sustained 1 MW fission reaction with a 35% conversion efficieny.

These calculations assume quite a bit and I wouldn’t use these numbers to design a real reactor, but they should give you a ballpark idea of the masses involved.

RTN wrote:

Thanks Stealthflanker . I kinda did the math on this based on the numbers that you provided . It seems Russian reactors for submarines are quite heavy compared to US ones . Not sure of the reason though .

How so ? I think US reactors aren't much lighter than Russian one considering they have somewhat excessive safety imposed on them.



This is only for the reactor compartment.. Which would mean it contain the reactor, steam generator and the foundation along with other structural member.

First, the power generation you mentioned in the kilowatt range for actual unmanned spacecraft is probably from a thermoelectric generator as opposed to a fission reactor.  


A thermoelectric generator converts the heat generated from natural radioactive decay into electric power.  Due to design considerations it is not practical for thermoelectric generators to be large enough to produce more than about a kilowatt of electricity.  Based on pure physics, however, here is the thermoelectric generator calculation.

Plutonium is often used in space applications because of its long half-life.  So, if a space craft is on a decades-long mission, A Pu power source should be able to function continuously.  The downside of plutonium is that it is extremely heavy.  Considering plutonium-238 for the moment, its specific power is 0.56 Watts/gm due to natural radioactive decay.  So, to generate 1 kW, we need 1000*0.56 gm = 560 gm or 0.56 kg.  This is thermal energy due to radioactive decay.  The thermoelectric generator which converts the thermal energy to electric energy has an efficiency of only a few percent.  For our example, let's assume a 5% conversion efficiency.  Then, the 0.56 kg will generate 0.05*1000 Watts = 50 Watts electric power, or, we can get 89 Watts per kilogram.  For 1 Kw, our mass is 11 Kg.  For  1 MW, our mass is 11,000 kg.

Now, onto a more practical means for generation 1 MW of power using a Plutonium fission reaction.  

To calculate the mass required to obtain a certain power level, we have to know the neutron flux and the fission cross-section.  Let’s assume the flux is 1E14 neutron/cm2/sec, the cross section for fast fission of Pu-239 is about 2 barns (2E-24 cm2), the energy release per fission is 204 MeV, and the Pu-239 number density is 4.939E22 atoms/cm3.  Then the power is

P = flux * number density * cross section * Mev per fission * 1.602E-13 Watt/MeV
P = 1E14 * 4.939E22 * 2E-24  * 204  * 1.602E-13  = 323 W/cm3

So, for 1 MW, we need  1E6/323 = 3100 cm3.  Given a density of 19.6 gm/cm3, this is 19.6*3100 = 60,760 gm or 60.76 kg.  

The next question to ask is: how long do you want to sustain this reaction?  In other words, what is the total energy output?

For example, a Watt is one Joule per second.  So, to sustain a 1 MW reaction for 1 year, the total energy is 1E6 J/s * 3.15E7 s/year = 3.15E13 J

For Pu-239, we have 204 Mev per fission and we have 6.023E23./239 = 2.52E21 atoms/gm.  So, the energy release per gram is 2.52E21 * 204 Mev/fission * 1.602E-13 J/Mev = 8.24E10 J/gm.

Therefore, to sustain 1 MW for 1 year, we will use 3.15E13 J / 8.24E10 J/gm = 382 gm of Pu-239 or 0.382 kg.  This is only a small fraction of the total 60.76 kg needed for the fission reaction.

Finally, this is thermal energy.  Our current light water reactors have about a 35% efficiency for conversion to electric power.  So, you can take these numbers and essentially multiply by 3 to get a rough answer for the total Pu-239 needed: 3 x 60.76 = 182 kg.  Rounding up, you would need roughly 200 kg for a long term sustained 1 MW fission reaction with a 35% conversion efficieny.

These calculations assume quite a bit and I wouldn’t use these numbers to design a real reactor, but they should give you a ballpark idea of the masses involved.

I've seen this math before.. Nonetheless haven't tried it.

Typical naval reactor however uses highly enriched uranium with level of 20-93% Mainly to prolong core life and to provide excess reactivity to allow rapid restart.

Their fissile energy should be higher than provided at the math above.
http://www.alternatewars.com/BBOW/Nuclear/US_Naval_Reactors.htm

The link deals with uranium enrichment to fissile energy.

for nuclear submarines weight is less of an issue its volume that is premium.
but i would agree with garry in ocean 1 on 1 diesel sub cant go against nuclear but in sea and coastal areas ...
the diesel sub is getting some very advanced technologies its cheaper and you can build and operate many more of them.

RTN wrote:Russian reactors for submarines are quite heavy compared to US ones

The math that you have provided does not prove that Russian nuclear reactors are heavier.

If we include  the weight of  the shield tank and foundation the weight of the reactor is bound to increase .

The exact clean weight of the OK 650 is therefore not known .

http://bmpd.livejournal.com/916623.html

Great photo of Monomach trials.

How can Russia commission Borei submarines without weapons?  Does the problems with Bulava missiles
have been fixed. ?  they were supposed to try again 6 more launches ,to finally be sure if it can do the job
after too many failures.

Vladimir Monomakh, Borei Class:

Vann7 wrote:How can Russia commission Borei submarines without weapons?  Does the problems with Bulava missiles
have been fixed. ?  they were supposed to try again 6 more launches ,to finally be sure if it can do the job
after too many failures.

I too would like to know the answer to this.  Borei has been plauged with problems and I found it silly they switched developers from ones who were traditional in SSBM's to ICBM's and vice versa. I like Borei, but what is the cost benefit and development if they went with producing upgraded Delta's instead and using Lyner missiles? Since the missile has higher success rate and all.

http://kuleshovoleg.livejournal.com/310054.html

Interesting. Boats starting with Knyaz Oleg, will have classical sail, not the sharply raked variant.

Vann7 wrote:How can Russia commission Borei submarines without weapons?  Does the problems with Bulava missiles
have been fixed. ?  they were supposed to try again 6 more launches ,to finally be sure if it can do the job
after too many failures.

I thought that the problems with the Bulava were fixed, maybe not...

TR1 wrote:http://kuleshovoleg.livejournal.com/310054.html

Interesting. Boats starting with Knyaz Oleg, will have classical sail, not the sharply raked variant.

Back to classical trademark of Rubin OKB   

5th Borei project 955A Princ Oleg

How can Russia commission Borei submarines without weapons? Does the problems with Bulava missiles have been fixed. ?

Lots of weapons throughout history have been put in service before all the bugs have been worked out... right now the choice between the Borei and the Delta IV subs is like the choice between a B-52 late model bomber and an upgraded B-2 but with a few faults that need work before it is ready for full combat status.

At the end of the day the Borei is the much more capable sub and the Bulava is the more capable missile. Giving contracts to companies with different experience is often a good way of jarring other companies out of their comfortable chairs.

An example is MiG, who got a different company to develop the optics for its MiG-35. the company is an optics company, but they worked with space based systems so they new the job but were new to the field of aircraft optics so they didn't know what could or could not be done... so they were likely more adventurous and less afraid to try strange solutions.

With Buluva it was a very ambitious programme and the result will be very capable when it is ready.

There is no other alternative so it makes sense to get the vessels into service even if all the missiles are not completely ready. When they are ready it will be fairly straight forward to get a large number of missiles directly into service.

It seems like they might really reach their 2020 deadmark... I doubted it at first, but they seem to be speeding things up.

RT says that an upgraded version of the Borei Class (project 955) will carry 20 SLBM missiles and not 16 like the previous ones..

http://rt.com/news/yury-dolgoruky-submarine-ceremony-678/

In May 2012 the Navy has also contracted development of [b]an upgraded version of the Borei class submarine, which will carry 20 ICBMs,[/b] compared to the regular version’s 16. It will also have improved characteristics, such as reduced noise, better measurability and more advanced weapon controls. The keel of the lead advanced vessel, Knyaz Vladimir, was laid down in July 2012, with four more submarines expected to be built. wrote:

And following more information.. Wikipedia  says the 4th Borei submarine .  
(K-??? Knyaz Vladimir) (project 955-А) lay down in 30 july 2012.. will be the one with 20 x Bulavas missiles.

http://en.wikipedia.org/wiki/Borei-class_submarine

So only the first 3 Borei I subs will be 16 bulavas and the upgraded version (Borei II) subs from 4th to the 8th submarine will carry 20 and with new advanced controls and more modern technology they testing that the first ones..

I thought that was already known... All Boreis after the first three will carry 20 Bulavas. - Which is great, should make the West change their diaper.

Actually I think that would be stupid... the current START treaty limits both sides to between 1,200 and 1,500 warheads each... which means 400-500 per service... 400-500 ICBM, 400-500 Cruise missile, and 400-500 SLBM.

Now if each of your SSBNs is going to have 20 missiles and each missile has... say 5 warheads... that means each vessel will have 100 warheads per boat. If the limit is 400-500 SLBMs that means 8 boats with 800 warheads... so according to that you can have 4 Boreis with 20 launch tubes and that is all in your entire SSBN fleet... which is pretty dumb.

With 16 missiles per vessel and 5 warheads per missile you can have 5, and with 12 missiles you can have 6 subs.

Obviously with 8 subs planned they will likely load them with 3-4 warheads and use the extra warhead space for decoys and jammers and other bits and bobs.

What I am saying is that it makes rather more sense to have more subs with fewer tubes than a few subs with lots of tubes.

GarryB wrote:Actually I think that would be stupid... the current START treaty limits both sides to between 1,200 and 1,500 warheads each... which means 400-500 per service... 400-500 ICBM, 400-500 Cruise missile, and 400-500 SLBM.

Now if each of your SSBNs is going to have 20 missiles and each missile has... say 5 warheads... that means each vessel will have 100 warheads per boat. If the limit is 400-500 SLBMs that means 8 boats with 800 warheads... so according to that you can have 4 Boreis with 20 launch tubes and that is all in your entire SSBN fleet... which is pretty dumb.

With 16 missiles per vessel and 5 warheads per missile you can have 5, and with 12 missiles you can have 6 subs.

Obviously with 8 subs planned they will likely load them with 3-4 warheads and use the extra warhead space for decoys and jammers and other bits and bobs.

What I am saying is that it makes rather more sense to have more subs with fewer tubes than a few subs with lots of tubes.

Only if, as you indicate, you intend to load each SLBM with a large number of warheads. Besides, maintaing a large boomer fleet is I bet more expensive than maintaining a smaller amount of subs with more tubes.

There is an alternative view - that while current treaties limit the number of warheads, such a restriction cannot be guaranteed as the US could elect to withdraw from START should relations degrade catastrophically. It makes sense to build SSBNs that can meet peace time treaty limits while only using (for example) 70% of total installed missile throw weight, and which have the option to sacrifice penetration aids to significantly upgrade the warhead load if required.

Cost is probably the major determining factor - ie which is less expensive? Adding 4x tubes to 5x Borei Mk II (ie 20 tubes total) or an extra Borei Mk I+ with the system upgrades but retaining the original complement of 16 tubes? I'd guess the extra boomer is a significantly higher cost? Plus the extra SSBN needs to be operated (extra crew trained) and maintained.