Tea-kettle nuclear submarines!

How ”regional” are actually these subs, Sarov and Gotland – could they be refueled with diesel at sea in order to get a wider range? How works refueling at sea – which kind of ships can do that?

More on the Hyperion reactor.
http://nextbigfuture.com/2008/10/power-to-overall-weight-ratio-aspect-of.html

Here are some images of the Canadian “SLOWPOKE”…

Another in the “nuclear battery” category, the Hyperion Uranium Hydride “battery”…

http://nextbigfuture.com/2008/05/hyperion-uranium-hydride-nuclear.html

Posted for fair use…
http://www.hyperionpowergeneration.com/about_finance.html

The Hyperion Power Module
When you think of the Hyperion Power Module (HPM), you can discard much of what know about nuclear power.
Hyperion is different.
Think Big Battery…

Like a battery, the HPM is a compact, transportable unit with no moving internal parts. It’s not to be opened once distributed from the factory.

Once sited safely in its underground containment vessel, an HPM is monitored but does not require a battery of operational personnel.. It just quietly delivers safe, reliable power – 70 MW thermal or 25 MW electric via steam turbine – for a period of seven to 10 years.

The core of the HPM produces energy via a safe, natural heat-producing process that occurs with the oscillation of hydrogen in uranium hydride. HPMs cannot go “supercritical,” melt down, or get “too hot.” It maintains its safe, operating temperature without the introduction and removal of “cooling rods” – an operation that has the potential for mechanical failure.

A good bit bigger than the typical consumer battery, HPMs are, however, just a fraction of the size of conventional nuclear power plants. About 1.5 meters across, the units’ size can be compared to a deep residential hot tub. It’s the size, along with the transportability and ease of operation, that make the self-contained HPM such a desirable choice for providing consistent, reliable, affordable power in remote locations.

Large conventional nuclear power plants are a necessary component of the global solution to the climate change problem. Nuclear power, including that provided by the HPM, emits no greenhouse gases. And, pound for pound its fuel component – uranium – delivers more actual energy than any other fuel available to today. Because its fuel packs more power, less is required. Therefore the mining of uranium is more efficient and causes less damage to the environment than traditional hydrocarbon fuels such as coal and natural gas. Nuclear power is also the safest, most regulated and protected form of energy on the planet today. No other industry is as closely monitored and today’s nuclear technology is constantly evolving as researchers strive on a daily basis to make it even safer.

Nuclear power will continue to play an important role in the global solution to the climate change problem. Now, because of Hyperion’s unique technology, the benefits of affordable energy from big power plants are available even when and where large, conventional nuclear power plants are not appropriate.

Think battery, with the benefits of nuclear power. Think Hyperion.

Hyperion Fast Facts

Small -1.5 meters across, approx size of a residential “hot tub”

Produces 70 MWt or 25 MWe, enough to power 20,000 average American homes or the equivalent

Buried underground out of sight and harm’s way

Transportable by train, ship, truck

Sealed module, never opened on site

Enough power for 5+ years

After 5 years, removed & refueled at original factory

Uniquely safe, self-moderating using a natural chemical reaction discovered 50 years ago

No mechanical parts in the core to malfunction

Water not used as coolant; cannot go “supercritical” or get too hot

No greenhouse gases or global warming emissions

Think: Large Battery!

Hyperium sounds like something you could add to an IEP ship such as a QE class Carrier or T45 destroyer in a refit by replacing Gas Turbines with them if the price of fuel got out of control. Depending on what support infrustructure is required, could something similar be seen on the Collins class replacement boats?

Here are some images of the Canadian “SLOWPOKE”…

Another in the “nuclear battery” category, the Hyperion Uranium Hydride “battery”…

http://nextbigfuture.com/2008/05/hyperion-uranium-hydride-nuclear.html

Posted for fair use…
http://www.hyperionpowergeneration.com/about_finance.html

The Hyperion Power Module
When you think of the Hyperion Power Module (HPM), you can discard much of what know about nuclear power.
Hyperion is different.
Think Big Battery…

Like a battery, the HPM is a compact, transportable unit with no moving internal parts. It’s not to be opened once distributed from the factory.

Once sited safely in its underground containment vessel, an HPM is monitored but does not require a battery of operational personnel.. It just quietly delivers safe, reliable power – 70 MW thermal or 25 MW electric via steam turbine – for a period of seven to 10 years.

The core of the HPM produces energy via a safe, natural heat-producing process that occurs with the oscillation of hydrogen in uranium hydride. HPMs cannot go “supercritical,” melt down, or get “too hot.” It maintains its safe, operating temperature without the introduction and removal of “cooling rods” – an operation that has the potential for mechanical failure.

A good bit bigger than the typical consumer battery, HPMs are, however, just a fraction of the size of conventional nuclear power plants. About 1.5 meters across, the units’ size can be compared to a deep residential hot tub. It’s the size, along with the transportability and ease of operation, that make the self-contained HPM such a desirable choice for providing consistent, reliable, affordable power in remote locations.

Large conventional nuclear power plants are a necessary component of the global solution to the climate change problem. Nuclear power, including that provided by the HPM, emits no greenhouse gases. And, pound for pound its fuel component – uranium – delivers more actual energy than any other fuel available to today. Because its fuel packs more power, less is required. Therefore the mining of uranium is more efficient and causes less damage to the environment than traditional hydrocarbon fuels such as coal and natural gas. Nuclear power is also the safest, most regulated and protected form of energy on the planet today. No other industry is as closely monitored and today’s nuclear technology is constantly evolving as researchers strive on a daily basis to make it even safer.

Nuclear power will continue to play an important role in the global solution to the climate change problem. Now, because of Hyperion’s unique technology, the benefits of affordable energy from big power plants are available even when and where large, conventional nuclear power plants are not appropriate.

Think battery, with the benefits of nuclear power. Think Hyperion.

Hyperion Fast Facts

Small -1.5 meters across, approx size of a residential “hot tub”

Produces 70 MWt or 25 MWe, enough to power 20,000 average American homes or the equivalent

Buried underground out of sight and harm’s way

Transportable by train, ship, truck

Sealed module, never opened on site

Enough power for 5+ years

After 5 years, removed & refueled at original factory

Uniquely safe, self-moderating using a natural chemical reaction discovered 50 years ago

No mechanical parts in the core to malfunction

Water not used as coolant; cannot go “supercritical” or get too hot

No greenhouse gases or global warming emissions

Think: Large Battery!

Debate regarding Canada acquiring nuclear submarines….

Canadian Naval Review
Acquiring Nuclear Submarines for Canada:
Are SSN’s essential to ensure Canada’s arctic sovereignty?
http://naval.review.cfps.dal.ca/forum/view.php?topic=36

Dalhouse University
Centre for Foreign Policy Studies
October 2007
BACKGROUNDER: VICTORIA CLASS SUBMARINES, NORTHERN
OPERATIONS & AIR INDEPENDENT PROPULSION
http://naval.review.cfps.dal.ca/pdf/AIP_Backgrounder.pdf

Here is more on the 80s proposal….
Posted for fair use….
http://en.wikipedia.org/wiki/SLOWPOKE_reactor

SLOWPOKE reactor

(acronym for Safe Low-Power Kritical Experiment) is a low-energy, pool-type nuclear research reactor designed by Atomic Energy of Canada Limited (AECL) in the late 1960s. It is beryllium-reflected with a very low critical mass but provides neutron fluxes higher than available from a small particle accelerator or other radioactive sources.

Basic design

The SLOWPOKE-2 uses 93% (originally) enriched uranium in the form of 28% uranium-aluminum alloy with aluminum cladding. The core is an assembly of about 300 fuel pins, only 22 cm diameter and 23 cm high, surrounded by a fixed beryllium annulus and a bottom beryllium slab. Criticality is maintained by adding beryllium plates in a tray on top of the core. The reactor core sits in a pool of regular light-water, 2.5 m diameter by 6 m deep, which provides cooling via natural convection. In addition to passive cooling, the reactor has a high degree of inherent safety; that is, it can regulate itself through passive, natural means, such as the chain reaction slowing down if the water heats up or forms bubbles. These characteristics are so dominant, in fact, that the SLOWPOKE-2 reactor is licensed to operate unattended overnight (but monitored remotely). Most Slowpokes are rated at a nominal 20 kW, although operation at higher power for shorter durations is possible.

History

The SLOWPOKE research reactor was conceived in 1967 at the Whiteshell Laboratories of AECL. In 1970 a prototype unit was designed and built at Chalk River Laboratories. It was primarily intended for Canadian universities, providing a higher neutron flux than available from small commercial accelerators, while avoiding the complexity and high operating costs of existing nuclear reactors. The Chalk River prototype went critical in 1970 and moved to the University of Toronto in 1971. It had one sample site in the beryllium reflector and operated at a power level of 5 kW. In 1973 the power was increased to 20 kW and the period of unattended operation increased from 4 hours to 18 hours.

The first commercial example was started up in 1971 at AECL’s Commercial Products Division in Ottawa; and in 1976 a commercial design, named SLOWPOKE-2, was installed at the University of Toronto, replacing the original SLOWPOKE-1 unit. The commercial model has five sample sites in the beryllium reflector and five sites stationed outside the reflector.

Between 1976 and 1984, seven SLOWPOKE-2 reactors with Highly Enriched Uranium (HEU) fuel were commissioned in six Canadian cities and in Kingston, Jamaica. In 1985 the first Low-Enriched Uranium (LEU) fuelled SLOWPOKE-2 reactor was commissioned at the Royal Military College of Canada (RMC) in Kingston, Ontario. Since then several units have been converted to LEU.

AECL also designed and built a scaled-up version (2-10 MWth) called SLOWPOKE-3 for district heating at its Whiteshell Nuclear Research Establishment in Manitoba. The economics of a district-heating system based on SLOWPOKE-3 technology were estimated to be competitive with that of conventional fossil fuels. However, the market for this technology did not materialize.

A Chinese version of the Slowpoke exists, designated the Miniature Neutron Source Reactor (MNSR). This version is nominally rated at 27 kW with similar characteristics and performance.

Autonomous Marine Power Source (AMPS)

During the early 1980s Canada briefly considered converting its Oberon class submarines to nuclear power using a SLOWPOKE nuclear reactor to continuously recharge the ship’s batteries during submerged operations. A good deal of work had been done on potential marine applications of the reactor at Royal Military College of Canada.

Another project by a Canada-France consortium, International Submarine Transportation Systems (ISTS) would have powered the world’s first commercial nuclear submarine with a 1.5Mw SLOWPOKE-type of reactor designed by Energy Conversion Systems Inc. This unit would provide the heat to power a Stirling engine. They got as far as building the craft, known as the SAGA-N, before the project collapsed in a tax dispute between Canada and France over funding.

[edit] Current applications

SLOWPOKE reactors are used mainly for neutron activation analysis (NAA), in research and as a commercial service, but also for teaching, training, irradiation studies, neutron radiography (at RMC) and the production of radioactive tracers. The main advantages are the reliability and ease of use of this design of reactor and the reproducibility of the neutron flux. Since the fuel is not modified at all for at least 20 years, the neutron spectrum in the irradiation sites does not change and the neutron flux is reproducible to about 1%.

Six of the original reactors are still in operation and one has been refuelled. Although all of the technical goals of this reactor were achieved, the lack of foreign sales was disappointing, the market being taken by the Chinese version.

I came across this notation in another forum…http://www.defensetech.org/archives/003918.html. One of the posters commented that the Canadians had looked into this in the 1980s and again for the Upholder/Victoria class boats (2400 tons displacement) they recently got from the UK.

The system they were proposing to use for an SSNK was a small nuclear reactor operating via the Rankine cycle to put power into the electrical drive/batteries.

Lipscomb also used that form of propulsion but was Sturgeon sized.

http://www.globalsecurity.org/military/systems/ship/ssn-685.htm

Sounds like Tullibee. It used a nuclear-electric drive and was 2600 tons submerged.

http://www.globalsecurity.org/military/systems/ship/ssn-597.htm

That’s exactly the sort of thing, thanks Sferrin. Give or take a few minor details, the Tullibee is pretty much the same idea. Modernised, it would probably use something like the modern podded propulsor pods used on cruise ships; this means no need for a hole in the pressure hull for the propellor shaft, but rather a simple set of electrical cabling. Add conformal sonar arrays, and a modern telescopic mast (again, no longer needing the classic periscope, prenetrating the hull); and overall, you’ve got the sort of thing I’m talking of. Go for something like the Hyperion reactor, but possibly even smaller (you should only need something like 10MWe), and it should still be capable of at least 20 knots.

No, the reactor uses a very compact steam turbine – but because of the liquid metal coolant, it can produce much higher ‘quality’ steam (i.e. a lot hotter). The steam is around 500’c, rather than the normal 250 degrees or so from a PWR. The steam plant is quite small, and pretty efficient. The point about the unit generating electricity directly is that the whole unit can effectively be a sealed unit. It is nothing like a nuclear battery, and uses existing technologies, though applies them in novel ways.

The reactor can be fail safe without being a PBR; in ones like the Toshiba 4S, it uses a negative temperature coefficient of reactivity (as it gets hotter, the power actually reduces). There are plenty of other ways of achieving a fail safe design – the term fail safe itself doesn’t really mean much. Basically, all you want is the ability for the reactor to shut itself down automatically if the reaction goes out of control.

Sounds like Tullibee. It used a nuclear-electric drive and was 2600 tons submerged.

http://www.globalsecurity.org/military/systems/ship/ssn-597.htm

Very interesting, both for possible submarine use, and also for conventional power generation. It is worth noting that the initial customers are in Eastern Europe – it is quite likely that they are very interested in replacing their current use of natural gas with nuclear power. It would make a lot of sense, and would, of course, also bring big benefits in terms of reducing susceptibility to any Russian supply threats. If Europe quickly moved towards far more reliance on nuclear power generation, then it would have a lot of knock-on effect politically. Though Russia would still be able to sell its gas, since China would buy it willingly, it would remove one of the largest political cards that Russia can play!

Interesting for navalization?
http://nextbigfuture.com/2008/08/hyperion-uranium-hydride-nuclear.html

I’m not really sure how Toshiba 4S can have a negative temperature coefficient of reactivity, as it is said to use neutron reflectors instead of fully relying on Doppler Broadening. The reflectors simply act in the place of control rods. Anything the reflector can do, the rod can do and vice versa.

PBRs alone are not fail safe. Truly fail safe means taking out all the control rods and yet the reactor will shut down. In this case, take out all the reflectors as well. You can still be ultra safe by putting all sorts of considerations on the control rods, but the ultimate definition of fail safe means to consider failure even of the control rods, and in this case, also of the reflectors which all have a mechanical moving factor (physically moved up and down into the reactor core).

Doppler Broadening effects are best exploited using a pebble bed fuel design, where the fissile material is formed and encased in a perfectly round object. The sphere expands in all directions equidistantly as temperature rises, reducing the fissionable density. This phenomenon isn’t going to be exploited properly if you got fuel shaped in rods.

Liquid Sodium and safety in the same sentence is something that needs some convincing at, especially to the USN which had its prior experience.

With only a nominal increase in size, from 2.0m to 2.5m in height, and a diameter from 0.9m to 1.2m, the Toshiba 4S can be had from a 10MW version to a 50MW version. That is powerful enough to power a small nuclear submarine on its own. In this case, it does not need to supplement an existing diesel-battery package, it can be the primary power plant on its own.

No, the reactor uses a very compact steam turbine – but because of the liquid metal coolant, it can produce much higher ‘quality’ steam (i.e. a lot hotter). The steam is around 500’c, rather than the normal 250 degrees or so from a PWR. The steam plant is quite small, and pretty efficient. The point about the unit generating electricity directly is that the whole unit can effectively be a sealed unit. It is nothing like a nuclear battery, and uses existing technologies, though applies them in novel ways.

The reactor can be fail safe without being a PBR; in ones like the Toshiba 4S, it uses a negative temperature coefficient of reactivity (as it gets hotter, the power actually reduces). There are plenty of other ways of achieving a fail safe design – the term fail safe itself doesn’t really mean much. Basically, all you want is the ability for the reactor to shut itself down automatically if the reaction goes out of control.

EdLaw,

I have to say I’m not familiar with what you call “tea kattle reactor”. How is it supposed to directly produce electricity? Like an isotope battery? Or like the fictious polywell?

Followed the polywell idea? Navy is financing it, so it looks like some people are nor absolutely sure it doesn’t work.

No, it’s not reinventing the Alfa class – they used the reactors to drive a steam plant, driving a shaft. In the tea-kettle concept, the reactor unit just provides electrical power, which is then used to power an electric propulsor unit. The whole point is that is takes up a lot less space, and is much less maintenance intensive than using a normal drive shaft.

Then you’re referring to Rickover’s “Holy Grail”, using MHD (Magnetohydrodynamic) principles to create electricity (not to be confused with MHD drive, which uses the same principle to create a propeller less sub).

Or are you referring to the use of RTGs?

Also, the problems of the reactor can be dealt with; there are a number of ways of avoiding coolant solidification, or dealing with it should it occur. The reactor can, obviously, sit on standby; but it is also possibly to keep the cooland artificially ‘warm’, and even re-melt the metal. Similarly, though many of the liquid metals are corrosive, that isn’t necessarily a problem, since there are materials that can be used that will not corrode. This is especially true of lead-cooled fast reactors, since they do not need to be pressurised, hence there are a number of alternative materials that are viable.

The aim, as I have stated, is not to build small nuclear submarines, but rather to build cheaper nuclear submarines. The size of these subs would likely be in the 3-4,000 ton displacement range, with crews of 50-70 (still large enough to have proper shifts, and maintain full damage control capability). A lot of the smaller submarines have small crews at the expense of capability. For instance, many can only muster a full set of crew when needed, i.e. by borrowing crews from the off-duty shift; which only works for short periods. With fifty or so, you can have two full shifts, with everyone that is needed for a tactical situation. This is one reason why, despite automation (etc…), the Collins has over forty crew, and the Japanese subs have even more, with around seventy crew.

Well the Alfa only had one less of 30. You don’t exactly build cheaper submarines by making them smaller; cost of submarine isn’t proportion to its size, weight and displacement.

A note on natural circulation. Most sub reactors today has some sort of natural circulation even if they don’t advertise it. The ones on the LA class, can run on natural circulation on low power settings. Those that do advertise this, are not pump less either, like those in the Ohio class. They still need the pumps in the high power settings or in case of emergency. What’s more important is to be able to increase the operating range of the reactor while using natural circulation before the pumps have to kick in. You need pumps as a final safety ace always.

Going back to the Alfa, yes there are ways to lower the required liquid temperature. But these ways involve adding additives like Bismuth, which makes the coolant corrosive and the additives themselves can result in being becoming radioactive under neutron bombardment either by becoming a radioisotope, or move up in the element chart to become a radioactive element (Bismuth to Polonium).

Sodium isn’t corrosive, but when exposed to water, reacts and one of the byproducts is hydrogen gas, which is explosive. Sodium, unlike lead, tends to become radioactive under neutron bombardment. Mercury, although liquid in room temperature, has been ruled out early due to being toxic.

Personally I tend to favor lead, not just because of its density and safety properties, but because it also acts as a radiation shield on its own, so you can actually reduce the size of the reactor, as the coolant acts as both coolant and shield. For some reason, the sodium cooled reactor can’t be pumpless, but the lead cooled reactor can.

Liquid Sodium reactor

http://upload.wikimedia.org/wikipedia/commons/e/e7/Sfr.gif

Liquid Lead reactor

http://upload.wikimedia.org/wikipedia/commons/b/b5/Lfr.gif

Now if you want a reactor to be fail safe, you would need a pebble bed design. There is only one currently operating pebble bed in this world, the HTR-10 in China, based on a working German design that was killed by politics, and another one being designed for South Africa. No design yet that combines pebble bed with liquid metal cooling. Basically the idea that you need a sphere—shape that is totally equidistant in all directions—in order to have Doppler Broadening, which is what you need to automatically kill nuclear fission once the temperature goes past a certain level. The idea that as the fuel becomes hot, heat makes the fuel less dense, and when its less dense, less nuclear fission will occur. HTR-10 has demonstrated that you can literally pull out all the control rods from the reactor, and the reactor shuts down by itself. The other advantage of having pebble bed, is that you can replace pebbles on the fly, take used ones out of the bottom and add new ones on the top, eliminating the need for expensive refits to refuel the reactor.

As for gas cooled reactors, the whole study about it is being of low power densit is focused on graphite moderated reactors but failed to account that the best power densities are produced by fast neutron or fast reactors. Fast reactors has the highest energy for its neutrons and tends to produce more neutrons than it needs to fission with. The excess neutrons can be used to convert thorium and uranium into plutonium as fissionable fuel, so the reactor actually generates more fuel as it goes. PWRs cannot be fast reactors, and can only be thermal neutron reactors, meaning neutrons that are rather “slow”, because water is a neutron moderating element by itself. But liquid metal and gas cooled reactors do not have such neutron moderation and can be used as fast reactors.

The other point about gas cooled reactors, using helium is that you can use the superheated helium to drive a Brayton cycle turbine (closed cycle turbine) without steam generation and turbines. Cutting out the steam circuit stage you can reduce the size of the system. Helium itself is inherently safe, it does not burn, its non toxic, and does not become radioactive (the radioactive isotope for Helium, He-5, has a 7.6×10−22 second half life) so the turbine it drives does not become radioactive

But you can cut out turbines even further with true direct MHD generation. The coolant itself must be electrically conductive and turned magnetic. For the most part, the preferred mediums are either liquid metal or gas in plasma or ionized form.

In any case, if we list down the smallest nuclear subs you can get some perspective of the technologies used and in respect to their size.

1. Smallest- Alfa class, roughly 2300mt surface, Liquid lead cooled Reactor with Shaft drive
2. Tied with 1. – Tulibee class, roughly 2300mt surfaced, 2700mt dived, PWR with turbo electric drive.
3. Rubis class – 2500mt surfaced, PWR with turbo electric drive
4. Skipjack class – 3000mt surfaced, PWR with shaft drive.

In comparison, a Kilo is 2300 mt surfaced, and a Collins around 3000 mt.

The fact that old subs like the Skipjack are already that small means that making nuclear subs small is a no brainer. They actually started small, and grew in size as requirements packed in. The Tulibee is another old sub. However, it should be noted that the shaft driven subs here are faster than the electric drive ones, with the Alfa <40 knots, and the Tulibee at 25 knots.

Not really sure about the Brazilian plan – they’ve been talking about it since the ’80s, but there don’t seem to be any concrete details available. They seem to be hoping to use their existing Tupi type (i.e. the German Type 209) as a template. This is a bit surprising, since the 209 is very much at the lower end of the size range. It is possible that they might intend to use what would amount to the forward half of a 209, but with a new aft section. They seem to be hoping for tech transfer from France, but that could be troublesome. I wouldn’t be surprised if they ended up with something very similar to the original French Rubis class, if they ever actually get the subs at all. A lot of grandiose plans are made by Brazil, but without the funding to actually do it properly. Just look at the Brazilian carrier Sao Paolo, which they got almost free from the French, and obtained a load of Skyhawks to fly from her; and yet they end up unable to afford to run it. I don’t say this to knock them, merely to point to recent examples of their ambitious plans falling apart due to the lack of money.

Is that the idea behind the Brazilian-Argentinean sub? Supposedly, and AFAIK, the Brazilians will place a compact Argentinean reactor into a French designed conventional vessel.

No, it’s not reinventing the Alfa class – they used the reactors to drive a steam plant, driving a shaft. In the tea-kettle concept, the reactor unit just provides electrical power, which is then used to power an electric propulsor unit. The whole point is that is takes up a lot less space, and is much less maintenance intensive than using a normal drive shaft.

Also, the problems of the reactor can be dealt with; there are a number of ways of avoiding coolant solidification, or dealing with it should it occur. The reactor can, obviously, sit on standby; but it is also possibly to keep the cooland artificially ‘warm’, and even re-melt the metal. Similarly, though many of the liquid metals are corrosive, that isn’t necessarily a problem, since there are materials that can be used that will not corrode. This is especially true of lead-cooled fast reactors, since they do not need to be pressurised, hence there are a number of alternative materials that are viable.

The aim, as I have stated, is not to build small nuclear submarines, but rather to build cheaper nuclear submarines. The size of these subs would likely be in the 3-4,000 ton displacement range, with crews of 50-70 (still large enough to have proper shifts, and maintain full damage control capability). A lot of the smaller submarines have small crews at the expense of capability. For instance, many can only muster a full set of crew when needed, i.e. by borrowing crews from the off-duty shift; which only works for short periods. With fifty or so, you can have two full shifts, with everyone that is needed for a tactical situation. This is one reason why, despite automation (etc…), the Collins has over forty crew, and the Japanese subs have even more, with around seventy crew.

Yeah they did, by exchanging the reactor to a normal PWR, that’s all they did to it, not really solving the problem at hand though.

Add to it that it’s most likely that an SSK won’t make 12 knots anyway. As for Orko, practically during evasive manoeuvring, it’s already too late. for a ship or submarine to go from say 5kts to 20 kts will take a long time, for gas turbine ones that’s more or less ok, but diesel/ electric driven ships will still take a long time to speed up.