The Great British SMR Off!

On your marks, get set, react! The Brits have announced 6 finalists to their SMR competition. Let’s find out who’s the star reactor and who’s got a soggy bottom.

Great British things can come in small packages! That’s why the UK has started the selection process for the tastiest SMR to help it deliver on its goal to expand nuclear capacity to 24GW by 2050. But with more than 70 SMR designs, where are they going to start? Earlier in the month, the UK government revealed a shortlist of six reactors that has earned their place in the tent.

This batch of reactors are decidedly conservative: fun-sized version of the classic Pressurized Water Reactors (PWRs) and Boiling Water Reactors (BWRs), reactors as timeless as a treacle tart. This makes sense given the government’s goal of finding the reactor “most able to deliver operational SMRs by the mid-2030s.” Speed is the name of the game, with the ambition of announcing the winner(s) in Spring 2024, and contracts awarded by Summer 2024, making this competition “the fastest of its kind in the world.”

Let’s take a look at the bake…with a mystery judge!

🇺🇸AP-300 by Westinghouse🇺🇸

The AP300 is the AP1000’s bite-sized brother, generating about a third of the energy of Westinghouse’s flagship AP1000. Even though the AP300 only made its debut in May, Westinghouse assures us the concept is far from half-baked: many components and modules used in the AP300 are the same as in the AP1000, which some have called a “large modular reactor”, meaning the two can share the same supply chain.

What’s even sweeter is the price: According to Westinghouse, each AP300 unit will cost $1 billion, a fraction of the AP1000. Further more, Westinghouse has had a strong presence in the UK for many decades, making its presence as familiar as an Eccles cake.

Angelica’s Verdict: What I can’t figure out is where the cost reduction is coming from in this SMR. What’s making it cheaper if you are using AP1000 components in a smaller reactor? In some SMRs, like the BWRX-300, there’s “system shedding”, that is, some feature can be entirely eliminated in a smaller reactor. But I don’t think that is the case in the AP300.

Mystery Judge: The AP300 electricity cost will be significantly higher than AP1000 for the reason you say. The Westinghouse folks know this, but the SMR is meant for smaller grids and reduced financial risks to customers.

🇬🇧The Rolls-Royce SMR🇬🇧

At 470MWe, this chonky-boi is more of a hearty loaf than a petit four, really challenging the definition of an SMR (generally 300MWe and under). However, what it lacks in daintiness, it more than compensates for with modularity…intense modularity.

According to Rolls-Royce, a staggering 90% of the SMR will be baked under factory conditions. This limits on-site activity to simply assembling the modules, which have been sized just right to ensure smooth transportation on British roads.

Yet, the crust seems to be cracking a bit. They've struggled to fill their order book and are running low on dough. “We’re facing a cliff edge.”

Angelica’s Verdict: To truly deliver the SMR premise (smaller...but also cheaper and faster), factory manufacturing needs to be in the recipe. However, as Rolls-Royce is discovering to their intense discomfort, you need significant dough— I mean, commitment— for your product before you can justify building your “bakery”. But who wants to invest heavily in an SMR without seeing one come out of the oven perfectly first?

This chicken-and-egg dilemma could be greatly alleviated with a dash of state support, making the stakes of this competition even higher for this local champion.

Mystery Judge: Let’s hope Rolls-Royce get as good at delivering projects as squeezing £££s from the UK government.

🇺🇸🇯🇵GE-Hitachi’s BWRX-300🇺🇸🇯🇵

This l’il boiling water reactor is the belle of the ball in the SMR world right now and with good reason: truly simplified system, nice price, and the learnings from the Advanced Boiling Water Reactor (ABWR), a model the Japanese were building on-time and on-budget between at 39-43 months, as the icing on top.

Ontario Power Generation (OPG) of Canada had a long and careful search of SMR models before settling on the BWRX-300, and they have gone all-in, committing to building 4 units on OPG’s Darlington site. The first unit is slated to be complete by 2028 and be supplying the grid by 2029, which would make it the first SMR make electrons outside of Russia and China (or at least nose-to-nose with NuScale’s Carbon Free Power Project).

Angelica’s Verdict: This is the closest thing we have to a sure thing in the nebulous world of tiny nukes. The Canadians have done their home work. This could be the future workhorse western nuclear. But what exactly is “modular” about this design? It seems to be just a tiny BWR, with some systems omitted.

Mystery judge: I’m skeptical of the unit cost reduction, but then again, I’m skeptical about that for more than one of those contestants. Also, are we sure the regulator is OK with all the systems they are eliminating?

🇺🇸Holtec’s SMR-160🇺🇸

The SMR-160 can produce superheated steam! We associate this ability with more exotic and advanced reactors, but Holtec achieves this with compressors to “boost” low-enthalpy steam. Daniel Lamb previously covered this intriguing new-entry in a previous post on Elemental.

This unique property (amongst this batch of contenders) makes the SMR-160 a match not just for power generation, but for providing heat to industrial processes that are otherwise difficult to decarbonize. The passive safety features in the SMR-160 also affords the reactor an “infinite grace period” in the case of an accident.

Angelica’s Verdict: The ability to produce super-heated steam is definitely hot! But on the other hand Holtec is a new player in the reactor space, though they are experienced in nuclear from their reactor decommissioning work.

Mystery judge: Too soon to tell.

🇫🇷NUWARD by EDF🇫🇷

Two PWRs in a pod! The unusual-looking NUWARD reactor came out of the French nuclear submarine program. They decided to put two identical 170MWe reactors sharing the same housing and system. The advantage is, you’ve got some flexibility, as one “pod” can refuel while the other keeps working.

The project was super quiet for a long time, and there’s whispers that the NUWARD was somehow unloved by EDF. But of late there has been a flurry of activity for the SMR that definitely looks the most like a macaron out of all of them. We’ve got a new subsidiary just to develop it, licensing activities, partnership activities…all with an aim to pour the batter in the pan…I mean pour concrete…by 2030.

Angelica’s Verdict: It’s a shame that the NUWARD seemed to have gotten lost in the shuffle until now. It’s 2023 and it is still in the conceptual design phase. Is it going to be up against a time crunch?

Mystery Judge: But don’t forget that the NUWARD has a capable team and they’re playing their cards right when it comes to licensing questions right away.

🇺🇸NuScale’s VOYGR🇺🇸

Once the world’s buzziest SMR, NuScale has been facing some cost blowouts that has put its first-of-a-kind construction, the Carbon-Free Power Project in the balance. What went wrong? Part of it is surely prevailing global conditions…after all, offshore wind projects also saw their costs increase by 50% too on recent commodity price gyrations and the end of the zero interest rate environment. But that’s probably not the whole story.

The counterargument is that probably all the others are going to have cost-blowout as they make the journey from “paper reactors” to fully-fledged designs too. And NuScale is the design that has come the farthest on the regulatory journey, earning it a design certificate from the NRC. No other SMR on this list can claim that milestone.

In any case, NuScale’s VOYGR module is 77MWe, quite small, but designed to truly be used as modules in a multi-module plant. They share a common “swimming pool” and can be operated independently for better ramping performance. Small but sweet? Or not worth the calories?

Angelica’s Verdict: NuScale’s small reactor size relative to the other SMRs do put it at a disadvantage, just thermodynamically. This is true in fact for all SMRs and a disadvantage they need to overcome through being easier and faster to build. But is NuScale in fact faster and easier to build? Let’s put the question to our mystery judge…

Mystery Judge: Nuscale did a good job at modularizing the reactor systems, but then they put the reactors in this enormous pool within the largest reinforced concrete building in nuclear history, making it probably the most expensive SMR.

That’s all we’ve got for you, dear readers. The real judgement will come soon enough from the UK Government. Will they support British tech by putting their weight behind the Rolls Royce reactor? Follow Canada’s lead and back the BWRX-300? Or pick one of the other lovely confections on display? Let us know in the comments what you think!

…and don’t forget, these delectable desserts are just the appetizers! The UK will of course also be investing in other nuclear reactors, both bigger and tinier.