What Are The Economics Of Pebble Bed Reactors

[bhobba]

Hi All

Out here in Australia you are not allowed to build a nuclear reactor. Even talking about it brings out the nut cases saying really intellectual carefully considered comments - Oh no not another nuclear nut. Further discussion usually indicates they don't even know the difference between Fusion and Fission so I usually just laugh and leave them to their ignorance,

However recently some opinion shows are now, horror of horrors, actually discussing nuclear because the voices wanting low emission base load power at prices compatible with coal is becoming louder. I of course agree this is needed - but as I explained it has in the past been shut down. I need to mention Australia is lucky we have plenty of Uranium, Thorium and Coal, plus huge amount of dessert well away from civilization to store waste. It's a standing joke here in Australia if anyone attacked us they would have to face General Outback and his troops the SASR, also known as the Phantoms of the Jungle - just a bit of humor.

One proposal struck me was talk of using Pebble Bed Reactors which I had never head of. I now have learned about them, and the articles said they produce electricity for about the same price as gas. But in the discussion it was mentioned while expensive to build initially compared to coal powered plants, the new ones have a life of 100 years making it the cheapest form of base-load power generation over its life cycle.

Is this true? If true for me its a no brainer solution to our power generation issues.

Thanks
Bill

 

[anorlunda]

Most of the things you read about them are unsubstantiated claims. Pebble beds have their own problems. So when the authorities finish making all the conservative assumptions, and safety feature requirements, who knows what it will cost?

I tend to view these things from their ability to attract investors. Investors have to worry that something may happen in the future which causes public support to flip and they loose all their money. Regulations can also change in the future. There are safer investments and AFAIK, no private party can be compelled to invest in energy infrastructure. Those concerns bias things in favor of low-initial-cost, short-lead-time, rapid ROI power projects, even if those kinds of projects return fewer public benefits.https://en.wikipedia.org/wiki/Pebble-bed_reactor#Criticisms_of_the_reactor_design

 

[etudiant]

With pebble bed, as with all things nuclear, the devil is in the details.
Germany built a modest size prototype at Juelich, it ran nicely for a while, then one night the feed mechanism that helps the pebbles circulate got jammed. The operators tried to dislodge the jam (with a broomstick reportedly) and broke over 40 of the pebbles, causing extensive contamination. That ended the program.

Imho, the incident again underlines how much nuclear is entirely dependent on unrelenting quality control. That was achieved in the US Navy because Rickover was fanatical about it and imbued his staff with the same zeal. Even today, if you go on a nuclear sub, you will be stunned by the ongoing detailed maintenance programs on board.
Getting the same dedicated effort to continue in civilian nuclear programs where economics are the cornerstone is pretty much mission impossible. (The Boeing MAX experience currently reminds us that this is not a problem unique to the nuclear industry.).
A further consequence of that is that neither the US nor Europe has the capability to build current generation reactors on any kind of a reliable budget or schedule, largely due to quality control failures at all levels exacerbated by opaque and uncertain regulatory guidance. That leaves the door open to new designs, perhaps driven by the push for reliable low emission power
If there were a nuclear power concept that was small enough to be self contained and manageable in the event of major breakdown, as well as self sufficient for an extended period with an essentially sealed design, it might achieve a break through.
Afaik, the Terrapower concept which attracted some funds from Bill Gates respects some of these criteria, but it appears to have lost favor, possibly for technical reasons.

 

[bhobba]

Damn, Feynman strikes again. Sounds errily similar to what he found with the Challenger disaster that was not even in the main report but only allowed in an appendix. Nature can't be fooled and you must account for all contingencies, which is especially important with nuclear. Ah well back to the drawing board.

Thanks
Bill

 

[DEvens]

As others have mentioned, the actual build and the approximation-laden theory often diverge. There are several reactor designs that people were confident of until they built one. Then they found that things they assumed were trivial were not really trivial. Here are just two.

Gentilly 1 and it's vertical fuel channels was a big issue.

https://en.wikipedia.org/wiki/Gentilly_Nuclear_Generating_Station#Gentilly-1The MAPLE reactor was supposed to generate medical isotopes. After a lot of heartache it was cancelled.

https://en.wikipedia.org/wiki/Multipurpose_Applied_Physics_Lattice_Experiment
On the other hand, the mature version of CANDU is doing really very well. Darlington Nuclear is exceeding 90% capacity factor life-time.

 

[anorlunda]

I have to put a plug in for my own former employer's (ASEA ATOM) design the PIUS reactor. It was intended to do what reactors are best at --- making hot water, not electricity. The hot water would have been used to provide district heating for the city of Helsinki. Yes, a reactor sited at the downtown of a major city. But alas, the press conference to announce the Helsinki project was preceded by the news from Chernobyl by 24 hours. Today it is even hard to find references to PIUS on the Internet.

http://www.i-sis.org.uk/CloseUpOnNuclearSafety.php
The PIUS design goal was “complete protection against core melting or overheating in case of any credible equipment failure, natural events such as earthquakes and tornadoes, reasonably credible operator mistakes, and combination of all those. In addition, the design should protect against inside sabotage by plant personnel completely knowledgeable about reactor design, terrorist attacks in collaboration with insiders, military attack, as by aircraft with ‘off-the-shelf’ non nuclear weapons, and abandonment of the plant by the operating personnel.

Such a PIUS light-water reactor was indeed designed by ASEA-Atom that would cost no more than a conventional plant with the same generation capacity. But to-date no PIUS plant has been ordered.

https://www.euronuclear.org/e-news/e-news-17/nps-kth.htm

 

[etudiant]

Wow, had no idea you worked on PIUS. Good on you!
The design always struck me as elegant, particularly the passive safety features .
Unfortunate indeed that the Helsinki deployment was prevented, it could have done a lot to bring the nuclear debate back to the real world.

 

[etudiant]

As others have mentioned, the actual build and the approximation-laden theory often diverge. There are several reactor designs that people were confident of until they built one. Then they found that things they assumed were trivial were not really trivial. Here are just two.

Gentilly 1 and it's vertical fuel channels was a big issue.

https://en.wikipedia.org/wiki/Gentilly_Nuclear_Generating_Station#Gentilly-1The MAPLE reactor was supposed to generate medical isotopes. After a lot of heartache it was cancelled.

https://en.wikipedia.org/wiki/Multipurpose_Applied_Physics_Lattice_Experiment
On the other hand, the mature version of CANDU is doing really very well. Darlington Nuclear is exceeding 90% capacity factor life-time.

With the caution that the Kakrapar reactor incident could have been very ugly indeed.
Even CANDUs have their glitches, but just as you say, the Darlington site is performing superbly. I believe it is the largest nuclear complex in North America and deserves to be seen as a model.

 

[Dale]

the new ones have a life of 100 years making it the cheapest form of base-load power generation over its life cycle.

Is this true?

Since none have been in operation for 100 years it is impossible to know.

 

[Jando]

You can never know the complete economics of nuclear reactors until you have found a way to get rid of the nuclear waste. What might seem reasonable now ("Just drop the waste into some desert") may not be reasonable in 20 years, not to speak about the next 200.000 years.

 

[Vanadium 50]

Unlike the excellent and well-thought out plan we have to dispose of fossil fuel waste.

 

[bhobba]

Unlike the excellent and well-thought out plan we have to dispose of fossil fuel waste.

Here in Aus an ex Prime Minister, Bob Hawke, was a big supporter of using the huge amount of desert we have as a dumping ground for nuclear waste. Even though he was not a new age type, he loved attending those kind of events where he was generally treated like a hero. But despite the boo's etc he was unwavering in that Australia should do it - it would be a good source of income. He was also equally unwavering in his support for Nuclear Power helping to save the planet - despite the same derision not only from new age types but the public in general. Bob had some failings, but forming his own view and sticking to it was not one of them.

Personally after reading this thread I am forced to conclude there is no magic bullet - the answer is what the experts mostly say - we will have a mix of power sources, including nuclear which whether the public likes it or not will need to be looked at. South Australia (SA), a state here in Australia, is looking at 100% net renewables by 2030:
https://reneweconomy.com.au/south-australias-stunning-aim-to-be-net-100-per-cent-renewables-by-2030/
Already SA has had a number of well reported blackouts. As Yes Minister made famous, that's extremely courageous Minister. We will see.

Thanks
Bill

 

[anorlunda]

Already SA has had a number of well reported blackouts.

That should have made headlines world wide, but it didn't.

It ought to be mentioned every time a politician in any country calls for 100%. But most people in most countries have never heard of the SA experience.

If energy policy is to be rational, then the only people qualified to set policy are electric power reliability engineers. ( Let engineers rule the world? It will never happen. )

 

[bhobba]

That should have made headlines world wide, but it didn't.

Its effects are still being felt:
https://www.abc.net.au/news/2019-08...d-as-regulator-launches-legal-action/11390760
Like I said - that's extremely courageous Minister.

Thanks
Bill

 

[anorlunda]

Like I said - that's extremely courageous Minister.

Thanks for sharing that. But from what the article says, it sounds like they are suing the wrong parties.

As the number of faults on the transmission network grew, nine wind farms in the Mid North of SA exhibited a sustained reduction in power as a protection feature activated.

For most, the protection settings allowed the wind turbines to withstand a pre-set number of voltage dips within a two-minute period.

When the protection feature kicked in, the output of those wind farms fell by 456 megawatts over a period of less than seven seconds.

When I worked at a grid operations company, we required all generators to supply the details of all such protective devices, and to adjust the settings to what the grid operator orders.

South Australia has an automatic load-shedding system designed to kick-in in just such an event.

But the rate of change of the frequency was so rapid, the automatic load-shedding scheme did not work.

Again, that is a failure of the grid operator.

Based on those two things, I think they should sue the grid operator, not the wind farms.

 

[russ_watters]

Thanks for sharing that. But from what the article says, it sounds like they are suing the wrong parties.When I worked at a grid operations company, we required all generators to supply the details of all such protective devices, and to adjust the settings to what the grid operator orders.

Do we know if the turbines were capable of operating with the settings the grid needs? Does the mix of sources affect it? E.G., below a certain percentage of wind it would be ok but above that percentage the settings no longer work? Who gets to decide who's responsibility it is if there are different entities with competing interests playing in the same sandbox?

 

[anorlunda]

Do we know if the turbines were capable of operating with the settings the grid needs? Does the mix of sources affect it? E.G., below a certain percentage of wind it would be ok but above that percentage the settings no longer work? Who gets to decide who's responsibility it is if there are different entities with competing interests playing in the same sandbox?

The grid operator (at least here in the USA) has an "interconnection agreement" they can enforce that imposes performance standards on the generators. A design incapable of doing what the grid needs would not meet that standard, and would be denied permission to connect to the grid.

In that sense, there is no parity, no ambiguity, in who sets standards and who must comply. Also in the USA, each regional grid operator must comply with the minimum standards published by NERC (National Electric Reliability Councils). So far, all these standards and mandates are private industry, not government.

Edit: I almost forgot. Using the miracles of modern power electronics, some wind farms are deploying "synthetic inertia" What that means is that they control the first and second time derivatives of voltage phase angle to mimic the dynamics of an old-fashioned steam turbine-generators to make the grid happier. IMO that is very clever use of modern technology.

 

[member 656954]

In terms of economics, it's not specific to pebble bed reactors, but some levelized cost of electricity (LCOE) forecasts for SMRs include:

• EY suggests a scenario where 10GW on an aggressive SMR learning curve is about £70/MWh
• a South Australian study came up with US$161/MWh
• NuScale has suggested around US$65/MWh which seems ambitious given larger PWR reactors have a higher LCOE.

Probably though, a 2017 EIRP report has the most likely summary on SMR economics, which concluded, "There is inherent and significant uncertainty in projecting NOAK [nth-of-a-kind] costs from a group of companies that have not yet built a single commercial-scale demonstration reactor, let alone a first commercial plant. Without a commercial-scale plant as a reference, it is difficult to reliably estimate the costs of building out the manufacturing capacity needed to achieve the NOAK costs being reported; many questions still remain unanswered ‒ what scale of investments will be needed to launch the supply chain; what type of capacity building will be needed for the supply chain, and so forth."

 

[Astronuc]

One proposal struck me was talk of using Pebble Bed Reactors which I had never head of. I now have learned about them, and the articles said they produce electricity for about the same price as gas. But in the discussion it was mentioned while expensive to build initially compared to coal powered plants, the new ones have a life of 100 years making it the cheapest form of base-load power generation over its life cycle.

Is this true? If true for me its a no brainer solution to our power generation issues.

It's difficult to quantify the life cycle costs since most graphite reactors, and particularly, pebble bed reactors, have been few and far between. One-of-a-kind systems tend to be very expensive and short-lived.

I was looking a Australia's electrical capacity/generation.
https://www.world-nuclear.org/infor...s-a-f/appendices/australia-s-electricity.aspx

For the sake of argument, let's assume the requirement is 60 GWe. For a 1 GWe standard plant, one would need 60 such plants to meet demand. If one considers a modular design (~ 0.2 to 0.30 GWe), the number of units needed doubles or triples.

Pebble bed reactors were developed in Germany over 20 years ago. At the Jülich Research Center, the AVR pebble bed research reactor rated at 40 MWth and 15 MWe operated for 22 years demonstrating that this technology works. The reactor produced heat by passing helium gas through the reactor core consisting of uranium fuelled pebbles. A steam generator was used to generate electricity through a conventional steam electric plant. Germany also built a 300 MWe version of the pebble bed reactor but it suffered some early mechanical and political problems that eventually led to its shutdown.

http://web.mit.edu/pebble-bed/papers1_files/Future for Nuclear Energy.pdf

 

[member 656954]

For the sake of argument, let's assume the requirement is 60 GWe. For a 1 GWe standard plant, one would need 60 such plants to meet demand. If one considers a modular design (~ 0.2 to 0.30 GWe), the number of units needed doubles or triples.

That is a great point that often gets glossed over, so thanks for putting some real-world figures into the mix, @Astronuc.

In fact, how to generate sufficient electricity to not only cover the current load, wrap in as much else as possible - BEV to replace ICE, HVAC to replace gas, etc. - and accommodate growth in energy use as developing nations develop is the open question with decarbonization. I do not view SMRs as a viable vector for this, quite aside from the waste issue and raised risk of radioactive material misuse. We've not proved they work as the promoters say; not proved they scale as the promters say; and not proved they as safe as the promoters say. If we're going to deploy fission, at least make it GW plants so we don't need as many of them!

 

[anorlunda]

If we're going to deploy fission, at least make it GW plants so we don't need as many of them!

LOL. Now you can see why public discussions are so difficult. Other people dream of modular, sealed, intrinsically safe, reactors small enough to put one in the basement of every apartment building. In public, you have to deal with all extremes of imagination. The probability of miscommunication is 1.

 

[member 656954]

small enough to put one in the basement of every apartment building

OMG, it's the crazed dream of the 1950s all over again

Just like Ford's fission powered car, that ain't ever going to happen!

 

[etudiant]

It is possible, perhaps even likely, that nuclear reactors could be hugely cheaper (95% to 99% less per watt) if they were mass produced. Assuming a standard 80% learning curve, the unit cost falls by about half for every tenfold increase in cumulative unit output.
That suggests that very small reactors are the key to lower cost nuclear. Build them by the millions and watch the costs plummet. We've seen this phenomenon with PC printers, which morphed from million $ chain printers to $100 ink jet printers, more versatile, multi color and with graphics the chain printers could not even dream about.
So the question is: Is it possible to build a home reactor, something that produces maybe 10-50Kwe, which is truly idiot proof?

 

[Dale]

Is it possible to build a home reactor, something that produces maybe 10-50Kwe, which is truly idiot proof?

It has to be not just idiot proof but also smart-terrorist proof.

I suspect that the former is possible, but not the latter.

 

[member 656954]

We've seen this phenomenon with PC printers

This is unfortunately a false equivalence on many levels. Product development that is dependent on a long-lived, toxic radioactive energy source cannot be undertaken in a typical R&D facility, or tested on consumers in the way electronic devices are so the iteration rate is well below 'PC printers'. Hence, you don't get the fast-fail cycles and competitive pressures that lead to incremental and innovative improvements in nuclear reactors of the kind we've seen elsewhere, including in the energy industry with PV and wind turbines.

Besides, the outrage, lawsuits, and cleanup costs when mistakes are made with fission-as-consumer-goods would be ruinous and regulators rightly / thankfully protect us from such. Imagine an inquisitive daughter trying to dismantle the "Homebody Nuclear Power Plant - Safe for every home (Trademark established, Patent Pending)" she found down the dump because some flipper had installed a new, improved version and didn't want to pay the disposal fee. It's going to happen, people are lazy, corrupt, stupid, <add your favorite term here>.

Indeed, the risk of societal harm from fissionable material is currently low because of the HUGE oversight and strict controls imposed on nuclear fuels and waste. But if fission products are readily available by aggregating cheap enough reactors that there is one in every home...well, apart from the mistakes made, you'd see terrorists creating atomic bombs, dirty bombs, and just dusting radioactive material in train stations, arenas, water supplies etc.

A reactor in every home is a concept from science fiction...and that's where it deserves to stay!

 

[DEvens]

It has to be not just idiot proof but also smart-terrorist proof.

I suspect that the former is possible, but not the latter.

I don't remember the name of the power station. But the operators were looking for an air leak in a wall that was supposed to be air tight. And they were doing it with a lit candle, holding it near holes in the wall that were supposed to be sealed inside the wall. A large number of cables were strung inside this wall. They managed to set the electrical insulation on fire. The resulting fire caused astounding amounts of damage.

The defense against terrorists needs to be such that there are easier targets. For example, the containment building for a CANDU is designed to survive, intact, the direct impact of a fully loaded 747. Thus, there are far easier targets.

Heh, it's amusing sometimes. I was involved in the safety report for a reactor. I got to the point where it was describing the qualification against traffic incidents on the various driving surfaces nearby. There was a pointer to the part about tornado qualification. Since the station was qualified to survive a flying gas truck impacting the reactor building, it was considered that it was qualified against any potential collisions in the parking lot.

 

[member 656954]

I don't remember the name of the power station.

It was the Browns Ferry Nuclear Plant in Alabama. Hard to imagine such a thing happening, but there you go...