In theory, it works in practice; in practice, it works in theory:

Why Energy Infrastructure is Not an Academic Affair

Important decisions about the future development of the energy industry must frequently be made by people who do not have intimate knowledge of...


...the technical aspects. These people are, nonetheless, interested in what a power plant will do, how much it will cost, how long it will take to build and how long and how well it will operate. When they attempt to learn, they become aware of confusion in the energy business.

There appears to be unresolved conflict on almost every issue that arises. This confusion stems from a failure to distinguish between the academic and the practical. These apparent conflicts can usually be explained only when the various aspects of the issue are resolved

...into their academic and practical components. To aid in this resolution, it is possible to define in a general way those characteristics which distinguish one from the other:

An academic power source or energy policy almost always has the following basic characteristics: (1) It is simple. (2) It is small. (3) It is cheap (4) It is light. (5) It can be built/implemented very quickly. (6) It is very flexible in purpose (’omnibus energy tech’).

(7) Very little development is required. It will use mostly off-the-shelf components. (8) The power plant is in the study phase. It is not being built now.

On the other hand, a practical power plant can be distinguished by the following characteristics: (1) It is being built now. (2) It is behind schedule. (3) It is requiring an immense amount of development on apparently trivial items. Corrosion, in particular, is a problem.

(4) It is very expensive. (5) It takes a long time to build because of the engineering development problems. (6) It is large. (7) It is heavy. (8) It is complicated.


The tools of the academic-power source designer are a piece of paper and a pencil with an eraser. If a mistake is made, it can always be erased and changed. If the practical-plant designer errs, he wears the mistake around his neck; it cannot be erased. Everyone can see it.


The academic-plant designer is a dilettante. He has not had to assume any real responsibility in connection with his projects. He is free to luxuriate in elegant ideas, the practical shortcomings of which can be relegated to the category of ‘mere technical details.’


The practical-plant designer must live with these same technical details. Although recalcitrant and awkward, they must be solved and cannot be put off until tomorrow. Their solutions require manpower, time, and money.


Unfortunately for those who must make far-reaching decisions without the benefit of an intimate knowledge of energy technology and unfortunately for the interested public, it is much easier to get the academic side of an issue than the practical side.


For a large part, those involved with the academic power plants have more inclination and time to present their ideas in reports and orally to those who will listen.


Since they are innocently unaware of the real but hidden difficulties of their plans, they speak with great facility and confidence. Those involved with practical power systems, humbled by their experience, speak less and worry more. Yet it is incumbent on those in high places


...to make wise decisions, and it is reasonable and important that the public be correctly informed. It is consequently incumbent on all of us to state facts as forthrightly as possible. Although it is probably impossible to have energy ideas labeled as "practical" or "academic"

by their authors, it is worthwhile for the authors and the audience to bear in mind this distinction and to be guided thereby.

Yours faithfully, Me.
I paraphrased Admiral Rickover, whose wisdom is applicable far beyond the academic, military & industrial complexes he created.

Vintage typesetting for nerds: http://ecolo.org/documents/documents_in_english/Rickover.pdf 
kudos @whatisnuclear who could've written this, but left me the honor and always @Astiburg @noorisk for putting in the hours. Let's hope @s_sommaruga and others consider these & remove barriers for practical solutions!

You can read the unrolled version of this thread here: https://typefully.com/beznauersetzen/9nukUfl

Why Molten Salt Reactors Are Harder Than Most of Their Developers Realize

This is another topic that I need to address for further reference because it keeps popping up throughout decades and continents.

First of all, let me assure you: I feel you, MSR fanbois, I've been there.

Armed with youth, climate angst, and a fresh B.Sc. in Chem. Eng. and Kirk Sorensen's Liquide Fluoride Thorium Reactor (LFTR) video, I set out to save the world. I took an M.Sc. in Nuke Eng. at a uni with solid traditions in advanced reactors

and worked @fzj_iek in nuclear chemistry research. On the way, I found out that, unlike most MSR/thorium fandom, saving the world is not about the silver bullet that no one cared to fire. Let's talk about that silver bullet called MSR before deciding how to save the world.

The argumentation is twofold: (1) dealing with large quantities of high activity gases and liquids is hard, as shown by the vast majority of numerous attempts (2) most Molten Salt reactors will involve those high activity gases and liquids. We can then talk about (3) what to do.

(1) The vast majority of high activity materials on this planet are solid and enclosed. This is why we don't have problems with them. Once they are (a) liquid, (b) gaseous, or (c) aerosols, problems keep coming with which only one kind of facility has been able to deal with (d).

(1a) High-activity liquids are bad, which is why the best practice is to solidify them with cement, glass, or ceramic. Liquids will have vapor pressure. Indicated by the vapor pressure, there will be evaporation. This is a transport mechanism of radionuclides (a) => (b,c).

(1b) High-activity gases are even harder to contain. In LWRs, there are also minuscule quantities, mostly from fuel cladding failures. The strategy is to delay them with charcoal etc. until their activity is reduced & vent them - hence the off-gas sys ending in chimneys.

(1b+) In MSRs, this strategy might work, but the quantities and therefore sys dimensions are 3+ orders of magnitude bigger. Consider that 1000+ times more mass and volume of fuel is constantly circulating in the primary circuit than in the case of an LWR with a defect cladding.

(1b++) Off-gas systems for MSRs are an active field of fundamental research, i.e. we don't know yet about maintenance, decontamination factors, and waste volume. We do know that we'll have trouble with heat loads, Krypton-85, and secondary sources of Xe-135 (from I-135).

(1c) As the fission products are bubbling from the salt, nuclear aerosols will be pulled out during normal operations. They have peculiarities like self-charging. There are scrubbers installed for emergencies at some NPPs, but the only facilities using them continuously

(1d) ...are those called reprocessing facilities. Sure, with a twist on the process that won't decrease the complexity of the off-gas systems, we can call it pyroprocessing. Those facilities always have had larger radioactivity emissions than nuclear plants - until MSRs come.

(1d+) Don't get me wrong, I like & advocate for reprocessing, but the reasons for that are for another thread. The point here is that MSR bros invariably have a blind spot for fission gases etc., which are gonna be 99+% released above the coolant but are a containment objective


(2) Okay, nice theory, but what does that have to do with MY MSR design? The Molten Salt Reactor term is incomplete, and if you have one of the few designs that are not salt fuelled, but salt cooled, sure go ahead and ignore all this. If you plan to just fill fuel rods

(2+) with salt, like @MoltexEnergy is rumored to be, you're still in for off-gas fun unless you weld those cladding like in PWRs. You either have pressure, volume, or an off-gas system. The whole thread got triggered by MSR bro quotes like "complexities don't apply to my design"

(2++) (because I, MSR bro, define complexities otherwise) "sure, there is regulation strangling the nuke industry, but it was put in place by the industry to limit responsibility" (cuts off a conversation on rad. emissions w/ lecture on thinly-veiled conspiracy theory) 

(2+++) (after pointing out that the white paper they made me read has the same blind spot as all the others, just assuming there won't be emissions) "In our closed fuel system, more precisely in an adjacent vessel, the venting has to be done" Dude, do you even closed system? 

(3) How do we save the world after all? I propose (a) stopping fuel cycle chauvinism (b) owning the complexity, and (c) solving it.

(3a) It's not 2010 anymore where just assuming you will operate an MSR will make you different and therefore cool. There are 10+ MSR designs out there. It's high time to admit that fancy core modeling by itself is not going to get any reactor operated. Once you look at regulation

(3b) you have to start owning the complexity. It involves not fighting it, and probably also realizing that radiation protection will apply to you as well as LWRs, thereby making you part of the (loathed) establishment. You might even end up with similar systems outside the core.

(3c) Once you own complexity, you have a chance of resolving it. You won't appease investors or politicians for long by putting "we're not LWR" on repeat. Instead, you must engineer systems that fulfill objective criteria like dose equivalents. Godspeed, nuke heroes of all fuels!

Inspiration to write this up came from the late Prof. Driscoll of MIT by way of @NickTouran who tweeted those eternal thoughts https://twitter.com/whatisnuclear/status/1533552559838810113 (although that table referenced in No. 5 on 0. Gen. reactors is missing - dig it up if you can please!) kudos @Polybertarian

Why Molten Salt Reactors are Harder Than Their Developers Think

In 10+ years of educational efforts aimed to expand knowledge about nuclear electricity generation, one question pops up again and again, with minor variations: how were the RBMK types at #Chernobyl different from today's reactors? I'll answer it here for future reference 🧵 

I found 5 technical differences to today's reactors that contributed to the accident. Whereas you might find reactors operating with any single one of these characteristics, I'd be surprised to find any reactor that has 2+ since supervision was globalized e.g. through @WANOComms

1. Lacking instrumentation and control meant that the operating crew rarely ever had an adequate situational awareness since they were busy w/ monotonous jobs. The automation was already low level for 1986, the Soviet Union was sanctioned through CoCom and was behind in all ICT.

2. Positive void coefficient. Neutrons don't care for the phase of the H2O they meet, but they care for the density, meaning that steam absorbs and moderates less of them. In RBMK, the neutrons breezing through steam get moderated but less absorbed in graphite. Heat => more heat.

3. Incorrect construction of the control rods (MCR1 below) gives incorrect and unexpected neutron dynamics. This is also referred to as the tip effect. It was known to Soviet researchers at the time but not shared through training and operating procedures.

4. No full pressure containment. Upon boiling off the water coolant, the biological shield was easily shoved aside by the expanding steam. The building above that was not pressure proof, it's just cheaper without all the concrete and steel.

5.Combustible graphite in the core provided a transport mechanism (=pollution) for the radioactive inventory once decay heat met the air. Once a reactor is open and dry there is going to be pollution, but not as much if it's only concrete or comparatively inert metals.

With these deficiencies and the tragedy of the lives lost, the dangers of nuclear fission have been maxed out. Claims regarding even worse scenarios e.g. @HBO are false and therefore misleading regarding energy policy. Chernobyl was terrible, but not top3 in NRG  deaths. end 🧵 