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Modular nukes: coming soonish.

I'm a bit distracted today, so blogging is going to be light. However, I notice with interest that NuScale Power, a US firm that specialises in modular nuclear reactors, has been given permission to develop its first plant on land owned by the Department of Energy in Utah.

Commercial generation is scheduled for...2024.


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Reader Comments (38)

Small Modular Reactors - SMRs - are one way the industry feels may help to break through regulatory ratcheting* and deliver affordable nuclear power.

The theory is that type approved factory assembled modules would not need to gain detailed approval at each and every site they would be deployed, and that a power station assembled of a number of mass produced smaller units might therefore be much quicker and cheaper to build.

As an engineering solution to a regulatory, rather than an engineering, problem, they have much to commend them.

One is reminded of the strange cathedral-like car engines of the pre-war period where long stroke allowed sensible displacement and power but at a lower legal 'HP' rating that was used for road tax assessment**.

*For a full description of this and other reasons why nuclear build costs have spiralled almost beyond reach, see the late professor Cohen's admirable online book


Feb 19, 2016 at 1:55 PM | Unregistered CommenterLeo Smith

Leo Smith, isn't 'Cathedral Engine' the term still used for massive 2-Stroke diesel engines, powering ships?

Small scale nuclear is the way to go. If you can put one in a submarine ........

Feb 19, 2016 at 2:09 PM | Unregistered Commentergolf charlie

Smaller size but normal problems!

Okay, the licensing of a design would be cheaper as no design change allowed.

But the site will need reviews and approval.

The build in the factory will be of a similar cost unless you suggest that certain components are no tested 100%.

Spacing between multiple modules, do we go worst case and allow for a catastrophic failure to stop all adjacent modules producing power?

Operating costs will be more: more refuelling machines/staff for individual modules, normal security staff/risk.

I can see some savings but not much.

Feb 19, 2016 at 2:10 PM | Unregistered CommenterSteve Richards

Perhaps we need modular Nugees to oversee the submarines?

Feb 19, 2016 at 2:36 PM | Unregistered CommenterNCC 1701E

@Steve Richards: I can see some savings but not much.

Please read Prof Cohen's book. Up to 75% of the cost of a reactor is meeting unique specialised regulatory hurdles. The physical cost of the reactor is non more than a coal plant really.

is the chapter to read. It only takes a few minutes.

The SMR protagonists themselves see cutting through bureaucratic red tape as the only reason to do what they are doing.

Sped of getting approval and of construction is the USP.

Feb 19, 2016 at 2:48 PM | Unregistered CommenterLeo Smith

Where can I get one!

Feb 19, 2016 at 4:27 PM | Registered CommenterLord Beaverbrook

Don't Westinghouse and Rolls Royce already have these available & commercial.

From memory Westinghouse reactors are load-following and soon to be available at Ikea.

I smell subsidy junkies & research grants!

Feb 19, 2016 at 4:33 PM | Unregistered CommenterGaznotprom

Steve Richards: I suggest you find out some more about them before commenting. For example, why would you want more than one refuelling machine for an array of identical reactors?

Why do people think a highly enriched (weapons grade) reactor of the type used in nuclear submarines would be licensable for commercial use?

Feb 19, 2016 at 4:52 PM | Registered CommenterPhillip Bratby

..Why do people think a highly enriched (weapons grade) reactor of the type used in nuclear submarines would be licensable for commercial use?....

My understanding is that NuScale use very low-enriched Uranium. And, of course, all sorts of different designs are now being built and modularised..

Feb 19, 2016 at 5:04 PM | Unregistered CommenterDodgy Geezer

Small modular nuclear plants will be the norm, especially for fusion generation. As the size of a fusion reactor increases, the power generated rises approximately by the cube of the core height. Its ability to get rid of heat rises only by roughly the square of the height. There are similar problems with the giant magnetic bottles required by typical reactors. Small reactors thus have a huge advantage. I look for desk-sized reactors in every neighbourhood by 2055.

I think that, at another site, I asked how many submarine reactors would it take to power London and I received an answer from a military type that he had considered the question in some previous role and that it would be totally uneconomic.

Feb 19, 2016 at 5:29 PM | Unregistered Commenterdiogenes

Nitpicking, but the reactor testing is proposed to be in Idaho - the company is based in Utah.
The same area as the first US navy submarine nuclear reactors were tested.

Feb 19, 2016 at 7:37 PM | Unregistered CommenterBengt Abelsson

Right now we just do not need nuclear in any form. From Leo Smith above: " Up to 75% of the cost of a reactor is meeting unique specialised regulatory hurdles." and that is the only problem with all the energy sources at the moment.
All we need until there are shortages (like real ones this time) are coal, gas and oil.
Coal, gas and oil will give us at last a couple of hundred years during which we would have security of supply, abundant energy and cheap energy. During the 200 years we would have ample time to refine renewables technology, storage technology and any other potentially useful ideas and see if they really are worth using.
Daft science and daft politicians are the only problem :)

Feb 19, 2016 at 8:07 PM | Registered CommenterDung

My guess is that it is based on the larger ........

Nuclear sub reactors are just too small for cities.

Feb 19, 2016 at 8:27 PM | Unregistered CommenterThe Dork of Cork

@Phillip Bratby, lets not be nasty now:

"I suggest you find out some more about them before commenting. For example, why would you want more than one refuelling machine for an array of identical reactors? My mistake, I did not notice that they proposed to construct the complete power station and possibly partially fill it with small ready built reactors.

What will the overall reliability figure be for a power station which consists of 12 identical units? Where each unit can experience a 'serious event'? 12 times worse or can some stats 'improve; the situation?

The concept of towing a 700 ton 'tested' reactor across country seems risky and would necessitate onsite testing which would increase costs.

"Why do people think a highly enriched (weapons grade) reactor of the type used in nuclear submarines would be licensable for commercial use?"</> Did I mention the grade of fuel? I think not.

Having read the Nuscale offering (and it is interesting) the concept - using natural circulation to extract heat from the core is not without difficulty. It would be reasonable to assume that the designers have done their sums and at full power, the natural circulation will remove all necessary heat, that the steam system will carry the heat to the turbines.

But, lets say we have a fuel rod rupture or a fuel rod is damaged and rod material gets trapped in the guides, uneven heating takes place in the core triggering a shutdown. A shutdown occurs, control rods released, core shuts down.

We now rely of natural circulation to remove the decay heat. But circulation is reduced slightly due to the above noted core damage.

Core temperature does not reduce as quickly as designed (not I say it still cools not rises).

There clever design allows for the surrounding outer pool of water to boil away cooling the reactor, when the water has all gone (not mentioned where the steam goes - lets just vent it!!!) then the system reverts to 'natural circulation' using air.

All well and good, but it the core cooled more slowly than planned, the water will boil away more quickly, and we will be relying upon air cooling for longer, causing the whole site to heat to unusually high temperatures.

Seems like there may be a few problems left to resolve.

Feb 19, 2016 at 10:01 PM | Unregistered CommenterSteve Richards

Submarine reactors in towns - can somebody confirm or deny that RR has had at least one (or more) sub reactor(s) running in Derby since the 60s?

At this rate we're going to have to buy thorium molten salt reactors from the Chinese, Indians or even mebbe the Koreans... I'd like to see Skunkworks truck fusion go... but things have gone quiet over there. There's always Flibe Energy ....

It used to be a metric of aircraft building that when the paperwork weighed more than the craft itself - it might be ready to fly - the nuclear regulatory business built on the paranoia about a too fast / instant sunshine chain reaction to drive even more paperwork into the engineering recipe for nuclear (as in - each "aircraft" had to be individually documented and approved at each "airport"....)

Feb 19, 2016 at 10:48 PM | Registered Commentertomo

"During the 200 years we would have ample time to refine renewables technology, storage technology and any other potentially useful ideas and see if they really are worth using." --Dung

"Refine" seems a bit optimistic. Some might say "develop," since renewables are impractical at this time.

"My guess is that it is based on the larger ........ Nuclear sub reactors are just too small for cities." --The Dork of Cork

Sensible and on topic. I hope all is well in Cork.

I wonder ... if the crowdfunding gamers of Star Citizen have considered where the electrons are going to come from to power their virtual universe.... cold, still winter nights - and no escape?

$100,000,000 + raised apparently - one wonders what a bit of tin rattling would do for novel nuclear?

Feb 19, 2016 at 11:36 PM | Registered Commentertomo


Feb 20, 2016 at 1:43 AM | Unregistered CommenterBruce

First of all, a geographic correction - the reactors would be sited in Idaho, not Utah. DOE owns the Idaho National Engineering Laboratory (INEL/INL), which started life as a test site for battleship guns, and then because the National Reactor Testing Station because it was a godforsaken wasteland where nothing could be grown. It will NOT be located in Utah - that is just the name of the corporation that is proposing to build it.

The first electricity generated by nuclear power came out of the EBR at the NRTS, and then the site hosted the construction of several naval nuclear power plant prototypes, including the one for the Nautilus and for the aircraft carrier Enterprise. It was the site of the SL-1 reactor, which had a quite spectacular accident, as well as the LOFT facility, which ran the only controlled destructive test of an emergency cooling system for a PWR. Many other "interesting experiments" were conducted there, and there are many research facilities and much technical expertise to support an experimental reactor program.

It would be a great site to test a new reactor design, under normal engineering considerations. Unfortunately, since the 1970s, it has morphed from a "godforsaken wasteland" into a "fragile ecosystem", so I imagine that the permission to construct and test a new reactor there will be a bit contentious.

DOE will probably contribute a bit of design and development money to the effort, and since the local expertise is very good, this proposal actually stands a chance of working. It will be intereting to see what sorts of costs they will come up with, for a real production plant at a non-INEL site, even in mass production mode. I suspect that the security guard force and security requirements will likely drive the cost higher than even an AP1000 or ABWR or SBWR. Modular designs have an allure that will only be tempered by expensive experience. (Note that the word is "expensive", not "extensive")

I wish them luck.

Feb 20, 2016 at 3:46 AM | Unregistered Commenterrxc

On my walk to work this morning i will pass 11 nuclear subs sat there doing nuthin the reactor cores are long gone no one takes a blind bit of notice of them really btw they will still be there in thirty years what a waste.

Feb 20, 2016 at 6:13 AM | Unregistered Commentermarc

Steve Richards: My comment was not meant to be nasty, if taken as such, then I apologise.

The comment about weapons grade fuel was not meant to apply to your comment.

However, you are still speculating about the design, without any basis for your speculations. Do you not think that the designers, safety engineers and reliability engineers will have thought through all the potential events? Will they not have done a risk assessment to determine all the potential fault sequences and what safeguards to put in place to handle them? Nuclear power is the safest from of electricity generation, despite the age of many of the existing plants and the much more simplistic safety cases that were presented for them when they were originally licensed. A modern one will be at least an order of magnitude safer (when measured in terms of risk of death or serious injury to a member of the public).

You can be sure that this design will have thorough risk-based safety case before it is granted a license (especially if it is built in the UK, where all sorts of bells and whistles, belts and braces will be added)..

Feb 20, 2016 at 6:43 AM | Registered CommenterPhillip Bratby

@Phillip Bratby, I am sure the designers have done all of the safety case work as well as possible.

However, the USP for this system, is: its small and modular, one design, so less cost.

Not sure that different sites, dragging 700 ton hardware around the countryside gives *such* enhanced safety.

I have nothing but praise for nuclear engineers and the overall design process, but the commercial imperative can cloud minds sometimes.

Feb 20, 2016 at 9:48 AM | Unregistered CommenterSteve Richards


You are correct in saying that we probably dont *need* nuclear power right now, from a theoretical perspective.

However North sea gas ran out, and fracking is still a political and economic minefield: The UK has no economically exploitable coal, and oil is far too expensive and renewable energy doesn't really work.

Maggie stockpiled enough coal to break the miners strike, maybe a years worth. I would be very scared of a stockpile of a years gas... but ten years of uranium would be small safe and simple. And would insulate the UK to a large extent from the vagaries of world fossil fuel prices. That's a big argument in favour of 'nukes now, not nukes later'

And the next reason is this: Ex of wartime conditions where massive risks are taken to push technology along, and billions are poured into it, the essential storage technology to make renewables actually work in a cost effective manner simply doesn't exist, and it's probably true to say that no one actually knows what it would be if it ever did exist. Or how safe it would be. The chance of 50 Megatons equivalent energy, stored to tide us over a winter, cutting loose doesn't bear thinking about. Look at what a few cubic feet of domestic gas supply can do to a house.

Whereas in excess of 50 Mt of fissile and fertile materials exists around the UK already, and none of it is able to go pop except under the most enormously precise conditions of an atomic bomb.

My points are therefore this.

1/. Energy security with fossil is very poor. Its hard and dangerous to store and we are reliant on bulk imports with the loss of North Sea production, and although fracking may buy us some decades, its not a long term solution either.

2/. Likewise with renewable energy of the intermittent kind, we end up with 'fossil with green stripes' - a fossil based grid with wind and sun as 'energy savers' - except they dont save energy because of the way they interact with the grid and the fossil generation...

3/. In all cases what is lacking is the holy grail of cheap safe reliable efficient mass storage of energy. about 200Mt equivalent for each year the current grid runs. By far and away the safest way to stockpile that sort of energy is inside a fissile or fertile atomic nucleus. For which we already have technology developed - albeit expensive - to utilise it.

4/. So long as other methods of achieving mass energy storage are in the end more expensive with their generation kit, and represent more risk, than nuclear, there is good reason to deploy nuclear rather than renewables + storage..

And right now the storage of 200Mt of energy in a releasable form that is safe and economic is frankly a few tonnes of uranium or plutonium or thorium. And nothing else.

The problem with billions of tonnes of gas under someone else feet, is that they are in the end under someone else's feet.

(NB: How come all that gas has stayed there for millions of years whereas a bit of nuclear waste cant stay there more than a hundred - or so the CND say).

Feb 20, 2016 at 10:31 AM | Unregistered CommenterLeo Smith

Steve Richards: Where do get this idea from that 700 ton hardware would be dragged around the countryside? Sizewell B, which had much more massive components than a MSR, did not involve dragging massive components around the countryside. All major components were shipped in directly by sea. Normal loads were brought in by road/rail.

Feb 20, 2016 at 10:50 AM | Registered CommenterPhillip Bratby

Leo Smith

I admit to a lack of knowledge about nuclear however I have spent a lot of time reading about shale in the USA and in the UK. I remember that when the drive to shut down our coal mines began we were said to be sitting on 300 years supply, maybe Phillip Bratby might have accurate figures for that?
You are extremely badly informed about shale though.
Without even considering any other areas of the UK, the Bowland Shale deposits in Lancashire contain enough gas to satisfy all our needs for 200 years plus. This is based on Cuadrilla reports about drilling through the only known shale deposit reaching a thickness of 6000 feet (at least). The big US shale plays are no thicker than 600 feet. The only things stopping us are the government and the Climate Change Act.

Feb 20, 2016 at 12:13 PM | Registered CommenterDung

@Phillip Bratby:

I read their website: 700 ton complete assembly can be towed to the site by truck as opposed to being built insitu.

"Dimensions – 76' x 15' cylindrical containment vessel module containing reactor and steam generator
Weight – ~ 700 tons as shipped from fabrication shop
Transportation – Barge, truck or train"

Feb 20, 2016 at 4:05 PM | Unregistered CommenterSteve Richards

Nuclear is ideal for electricity generation for the reasons Leo Smith lists above. It's damn all use for much else except making bombs.
Oil and coal on the other hand have many uses — I can count a dozen from where I'm sitting, starting with this pesky machine! I'm not a believer in "peak oil" (or peak anything) but that's no good reason not to use a clean, reliable, abundant source when the alternatives are essential for the production of other things. That is simply good use of resources.

Feb 20, 2016 at 8:12 PM | Registered CommenterMike Jackson

Steve Richards,

Phillip has it right - you shouldn't comment on a subject you are obviously ignorant about. Every "problem" you raise is basically being made up by you.

Transporting - non issues. They have transported larger reactors before. One of the reactor vessels for the two new Vogtle plants in Georgia was recently transported to the site by rail.

"Serious" event - wtf? Because the word nuclear is involved you apparently start shaking at the knees and imagining all sorts of terrible things. Don't worry, mommy will give you a hug. One of the nice attributes about the moduler design is that they are inherently safer. With natural circulation cooling and a gravity fed emergency cooling pool, accidents due to equipment failure are eliminated. Just because you can invent an accident in your head doesn't mean it can happen. The US alone has something like 50 million hours of reactor operations. Can you reference an incident where your failure scenario occurred?

Feb 20, 2016 at 9:35 PM | Unregistered Commentertimg56

> Not sure that different sites, dragging 700 ton hardware around the countryside gives *such* enhanced safety.

700 ton is peanuts. The record is 8 evaporator units for a desalination plant. Each evaporator weighed nearly 5000 tons and they went from South Korea by ship to Saudi Arabia and then by road to their final destination.

Transporting nuclear reactors is not new. When the Yankee Rowe Nuclear Power Station was decommissioned its reactor vessel was transported by road to the local railway. It then went by rail, passing through 9 states, until it reached its destination in South Carolina.

Feb 21, 2016 at 12:15 AM | Unregistered CommenterTerryS

Modular nuclear reactors were built in the 1950s. Two of the earliest polar ice cores (Camp Century, Greenland and Byrd, Antarctica) were drilled at camps powered by modular nuclear reactors. They were delivered by air.

Feb 21, 2016 at 2:26 AM | Unregistered CommenterSteve McIntyre

The SL-1 reactor (built at the Idaho Nuclear Engineering Laboratory) was a modular military reactor designed to be shipped by helicopter to remote arctic regions to provide heat and electricity. Unfortunately it never got off the ground (literally) due to an operator pulling out a control rod (for reasons much speculated about). All that remains is a bit of capped rubble in the desert. I recall reading all about it in a fascinating book many years ago, unfortunately I no longer recall the book. Some information can be read at radiationworks and at Atomic Insights

Feb 21, 2016 at 6:53 AM | Registered CommenterPhillip Bratby

Leo Smith wrote: " I would be very scared of a stockpile of a years gas..."

The great thing about gas is that you won't need to, not if the shale is as good as suggested. It is already stored in the ground and when you don't need it then you just leave it in situ.

We are just going through our second winter with a proper central heating system -- the Rayburn gave up the ghost -- and our electricity use is way down as we use oil-heated water. Instead of fossil fuel being used to generate hot water to drive a turbine to produce electricity to be sent along wires to run through an immersion coil to heat water, now the oil is burnt to heat water. Wouldn't it be nice if I could run a little gas-powered genny and use the waste heat to heat water. Wouldn't it be nice if I could produce heat during the winter and export spare electricity to the grid.

We don't need nukes yet, not if the shale is there. All we need is for someone to notice that the world doesn't seem to be heating up in accordance with AGW projections.


Feb 21, 2016 at 10:15 AM | Unregistered CommenterJulian Flood

Mike Jackson

My view is that we should aim for the fastest and cheapest method of powering our economy because the future is uncertain. Regardless of whether we face military conflict, global economic problems or natural disasters we will best survive them with an advanced technology which comes from an advanced economy.
In the short term trying to pick out which resource to prioritise and which to preserve is a waste of time and effort :)

Feb 21, 2016 at 2:22 PM | Registered CommenterDung

The largest load transported in the UK by road was a 640 ton transformer for 100 miles, and took 9 months in planning:

The world record at 5000 tons, an evaporator travelled on road for 2km:

I think there is a difference between transporting a large evaporator and a fully tested and sealed reactor vessel.

Also, the modular nuclear reactor airlifted to the Greenland Camp Century were fully built, then broken down into modules into sizes suitable for transport by C-130 aircraft.

Not quite the same as a 'complete' assembly ready to go.......

Some seem to think I am negative about this, I am not, I just think the hype needs to be tempered with a bit of commercial and practical reality.

Feb 21, 2016 at 5:59 PM | Unregistered CommenterSteve Richards

I have space in my basement for a couple.

In case of cyclones.

Power cuts.


Feb 21, 2016 at 9:18 PM | Unregistered Commenterjones

"It's damn all use for much else except making bombs."

1. them bombs are going to build no matter what you do re "proliferation"..NKorea and Iran need far less fission material as they all go for booster fission which requires only a fraction..Thats why they had no problem "negotiating" a reduction in centrifuges, they have enough fission material for 1000 bombs already.
it is nonsense to keep trying "not to proliferate", is like stopping smugglers, is a wack-a-mole game where everybody gets what he wants except gets rich on top.

2.nuclear should be used in food preservation..all bacteria perishable goods actually
a small radiative element in your fridge would allow to keep the milk and salad FRESH for 6months++
This would create BILLIONS in extra wealth

3.medical.radiation is about the ONLY thing that penetrates and sweeps out tissues in your body where your immune system maybe has difficulty reaching.Is like soap for the skin, but for your insides. In fact it is , next to aspirin perhaps, very much the ONLY soap. thats why chernobyll did not cause extra deaths over Europe: it SAVED 10s of 1000s of lives (prolonged lives, but unseen to statisticians, because they did not "want" to see the effect)
Radiation should be extra added to TAP WATER !

Feb 22, 2016 at 10:33 AM | Unregistered CommenterVenusCold

Here is a picture of a small modular reactor afloat in The Solent !

How small is that ?
Much smaller than you'd think.
This next picture shows how small a part it is.

The Rolls-Royce Pressurised Water Reactor is a Small Modular Reactor !
Great Britain has been making them and using them to power Submarines for decades !

Feb 23, 2016 at 7:31 AM | Unregistered CommenterClimate Change Chronicle

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