[philipkglass]

I think that the US Nuclear Regulatory Commission is world-leading. They identify problems proactively and require operators to phase in safety upgrades even for plants built 50 years ago. I live near an operating nuclear reactor and I prefer it over any form of fossil plant. Power reactors operating in the United States are reliable, safe, and have extremely low life cycle emissions of greenhouse gases.

Unfortunately, one of the most common refrains from nuclear boosters is that nuclear power is over-regulated. I don't want American nuclear plants held to the same lax safety/environmental standards as fossil plants. If we used taxes to internalize the costs of pollution from fossil-fired plants, low cost natural gas plants probably wouldn't be pushing reactors into early retirement. But leveling the playing field by slashing nuclear safety/inspection down to the low standard expected of fossil plants is the wrong way to go.

I am open to specific proposals for reducing regulations in the nuclear sector if there are regulations that impose additional process overhead, don't actually serve a purpose, and survive only from inertia. I wouldn't be surprised to hear that there are some of these. But I've been discussing nuclear power for 20+ years, starting back on Usenet, and specific proposals are much less common than generic "get rid of red tape" bluster.

[credit_guy]

Here, I'll come up with a proposal. If Congress is serious about climate change, then they can ask (and allocate the budget) the Department of Energy to procure and operate a bunch of naval nuclear reactors. With whatever internal regulations they have, the US Navy has not had a single incident in their entire history of operating nuclear reactors. They are also quite cost effective, for example the cost of the 2 reactors A1B [1] that power a Gerald Ford carrier is about $1 BN. That comes to about $2BN/GW, which is about a tenth of what a civilian reactor costs. The US Navy builds about 1 carrier every 4 years so that comes to 1 reactor every other year. If the DoE gets the Congressional mandate to procure a few reactors per year, the cost is going to surely come down. Also these reactors don't need refueling for about 2 decades, while civilian reactors are refueled every 1.5 years.

[1] https://en.wikipedia.org/wiki/A1B_reactor

[sir_bearington]

This is not a very good idea for several reasons. Naval reactors require fuel that is much more enriched than normal reactors. They also produce significantly lower electricity. The Palo Verde facility produces 3GW of electricity and cost $11B in 2019 dollars. Each of the A1B reactors generates 125 MW. Life span of the reactor is not specified, but it's predecessor the A4W had a 23 year life span. By comparison, new nuclear plants are slated to last 50-80 years.

The net cost per GWh of electricity of the naval reactor is significantly worse than commercial plants. This is to be expected, because naval reactors are built to be compact and withstand the rocking of a ship at sea. Commercial reactors can leverage the efficiency of larger scale, and are built to be much more long lasting.

[credit_guy]

An A1B generates 125 MW electricity, but also 260 MW of additional thermal power used to power the propellers. If you convert the latter one to electricity at a 45% efficiency (typical efficiency for a generation IV nuclear power plant steam turbine), you get 117 MW, for a total of 242 MW. Two reactors could produce then about 0.5 GW. At a $1 BN cost, that's $2 BN / GW.

Palo Verde was brought online more than 30 years ago. If you look at Vogtle 3-4 (to be brought online in the next 2 years... if we are lucky) or Hinkley Point C, you'll see projected costs of respectively $25 BN for 2.5 GW and $32 BN for 3.2 GW. In both cases that comes at $10 BN/ GW. That is 5 times more expensive than the naval reactor.

Now, as you said, the cost of a naval reactor is very likely inflated by the exacting demands of its military usage. It needs to be compact, to work on a rocking ship, presumably it needs to be able to survive a certain amount of abuse that's to be expected if a ship/boat actually participates in combat, and I'm sure there are 100 other things that I'm missing here. All these factors make military devices absurdly expensive compared to the same devices intended for civilian use.

The logical conclusion is that if DoE wants to repurpose naval reactors for civilian use, then it can achieve significant cost savings. What I'm saying is that even not factoring these savings in, you still end up 5 times cheaper than the civilian reactors that are currently being built.

Edit: The lifespan of a Gerald Ford-class carrier is expected to be 50 years. The Nimitz aircraft carrier was launched 49 years ago. They do not replace their reactors. So, a naval reactor is designed to work for at least 50 years.

[sir_bearington]

You also need to build a secondary containment vessel for the reactor, which is a significant expense. Because the cost of this containment is a function of surface area and generating capacity is a function of volume it's better to increase size. You also need to build steam turbines, heat exchangers, transformers, etc. The cost of the reactor is only a portion of the cost of the whole nuclear plant.

> Palo Verde was brought online more than 30 years ago. If you look at Vogtle 3-4 (to be brought online in the next 2 years... if we are lucky) or Hinkley Point C, you'll see projected costs of respectively $25 BN for 2.5 GW and $32 BN for 3.2 GW. In both cases that comes at $10 BN/ GW. That is 5 times more expensive than the naval reactor.

And by comparison you have the Taishan plant built for $7.5B with 3.5 GW generating capacity. If we want to go around cherry-picking examples we can also cherry-pick the cheap plants.

We have already tried using maritime nuclear reactors for grid generation. The first nuclear plants brought online for grid generation were maritime reactors repurposed for grid production. Larger purpose-built reactors won out.

[epistasis]

Vogtle and Hinckley aren't cherry picking expensive plants, it's cherry picking middle of the road.

VC Summer is expensive, many billions spent and nothing to come of it ever.

Where do your cost numbers from Taishan come from? How do you come to costs that are believable from massive Chinese construction, or at least a cost that might be transferable at all to the rest of the world?

The history of nuclear is very clear: keep on increasing costs throughout construction, just enough that, taking into account the sunk cost fallacy, it makes sense to soldier on. VC Summer overshot that, and had massive corruption in the auditing of all parts of the project. Somehow Vogtle continues.

We literally do not know how to build nuclear in a cost effective manner any more. We can't structure contracts in the right way, we can't perform engineering to a high enough degree to make constructive plans. At Vogtle they literally poured the wrong concrete, and had to go back and get the design recertified with the NRC, because the original design was impossible to build, and on site they just plowed ahead with what they thought they could build. This is the level of incompetence, ball dropping, and bad contract structure.

Perhaps this sort of thing is fixable, but not on any reasonable timeline. The management is rotten from the top, so there's nobody that we can even order a nuclear reactor from.

Suppose you had $7.5B and wanted 3GW of nuclear at one of the many sites in the US that would welcome nuclear and its jobs. Who do you even bring that money to in order to build it? Rosatom? Are they going to meet NRC standards?

[bob29]

Great by the same logic you should use a commercial reactor over a naval reactor, you should also just use a different power source over nuclear.

[sir_bearington]

What other power source generates carbon-free energy without intermittency or geographic dependency?

[lostlogin]

The construction, fuelling and cleanup of a site is far from carbon zero. There is also a geographic dependency, or should be.

Nuclear power puts out more CO2 than solar or wind according to Nature (hydro isn’t mentioned for some reason).

“carbon emissions ranged from 1.4 grammes of carbon dioxide equivalent per kilowatt-hour (gCO2e/kWh) of electricity produced up to 288 gCO2e/kWh. Sovacool believes the mean of 66 gCO2e/kWh to be a reasonable approximation.”

https://www.nature.com/articles/climate.2008.99

[epistasis]

Solar + wind with storage and a grid. The parts are all there, and it's cheaper than nuclear today.

[sir_bearington]

No, the storage part is not there. Hydroelectric storage is expensive, takes a long time to build, and is geographically dependent to boot. Only ~5 minutes of global electricity storage can be provided with batteries using all known lithium deposits. Only 19 minutes worth of storage is available with all the lithium we can mine with today's equipment [1].

This is why plans for a solar and wind grid assume that some silver bullet is going to provide dirt-cheap and nigh-infinitely scalable storage.

1. https://dercuano.github.io/notes/lithium-supplies.html

[imtringued]

Nuclear power plants are thermal power plants and that means they need cooling. The power density of nuclear power plants is so high that most of them can't be placed near rivers because rivers have a variable flow rate.

If the flow rate is too low you risk killing aquatic life in the river ecosystem so instead the nuclear plant is turned off. You can avoid this by placing the nuclear power plant near the ocean. That's what the Japanese did with the Fukushima power plant even though it's a tsunami prone area.

[sir_bearington]

What gives you the idea that nuclear power plants can't be placed near rivers? Almost all that aren't on the coast are near rivers.

And they don't need to use potable water. The Palo Verde plant uses wastewater.

Because humans need water to survive, all population centers are built with access to water. Thus, cooling is available pretty much anywhere one would want to build a nuclear plant.

[bob29]

So you can build nuclear in a tsunami zone? in a seismic zone? in an area without cooling?

So you can mine and enrich uranium without carbon?

Nuclear does none of the things you fantasize it to do really.

[sir_bearington]

> So you can build nuclear in a tsunami zone? in a seismic zone? in an area without cooling?

Yes, you harden the structure against tsunamis and earthquakes. That's part of why nuclear plants are so expensive.

Atmospheric cooling can indeed be done anywhere. It's typically easier and more efficient to use water cooling. And humans need water to survive, and thus population centers are built near sources of water, water cooling is almost always an option. Also nuclear plants can be cooled with seawater.

This is in stark contrast to hydroelectricity which needs both a river and a valley to be viable. Geothermal power needs magma near enough to the surface to heat water into steam.

> So you can mine and enrich uranium without carbon?

I don't see why not. Use electricity produced by nuclear plants to drive centrifuges. Also use said electricity to power mining equipment.

And you didn't answer my question: What other carbon-free sources provide energy 24/7, besides ones that need very specific geography like hydroelectricity and geothermal power?

[rurounijones]

> So you can build nuclear in a tsunami zone? in a seismic zone?

Why not? It worked at Onagawa: https://www.sciencedirect.com/science/article/pii/S259012302...

[philipkglass]

The US stockpile of HEU would be depleted a lot faster this way, but enrichment could start again. I don't see major downsides to this proposal. Thanks for providing a specific and plausible idea!

[Hammershaft]

Thats a great idea. I'm trying and failing to find gotchas.

[credit_guy]

There is a potential gotcha: proliferation potential. The naval reactors use highly enriched uranium; if it falls in the wrong hands, you can end up with someone being able to build a bomb. That's why I said such a program needs to be run by the Department of Energy, the same department that has to maintain the nukes. I don't have a personal objection to this, but a lot of people would be unhappy with an essentially military program to be established for a problem that is not military in nature.

[obelos]

Hopefully the DOE will continue to be led by a person who didn't previously campaign on disbanding it!

[zepearl]

> I think that the US Nuclear Regulatory Commission is world-leading.

Comparisons are irrelevant - Japan's regulations weren't the worst in the world when Fukushima happened => something similar could happen anywhere else (a lot of factors influence a lot of decisions/policies - the past years demonstrated that even the US nowadays isn't the most stable country).

> They identify problems proactively... even for plants built 50 years ago.

Maybe they do "now" (I'm not a "pro" in this area therefore I cannot confirm nor deny that) but in any case there are never guarantees about the future. Additionally that "even for" sounds ugly - that MUST happen as long as such a plant exists.

> I live near an operating nuclear reactor and I prefer it over any form of fossil plant.

It's well-known that fossil plants are the absolute worst => such a change isn't a great improvement from my point of view.

> Power reactors operating in the United States are reliable, safe...

So far, and the terms are flexible - incidents did happen with civilian & military reactors, Wikipedia has a lot of nice-to-read articles with timing summary, analysis etc... .

> ...and have extremely low life cycle emissions of greenhouse gases

Correct - basically almost 0 (don't know, probably the truck that delivers the uranium stabs does generate some gases, maybe as well the mine&plant that create them, but not a lot compared to gas&oil&coal). But then... that's it? No other remark about maybe what is generated and where to put it and how to take care about it for the next 10000 years?

I'm definitely not/never going to approve any measure to deregulate a sector which has a near-infinite potential impact when something breaks and/or something is not properly taken care of.

[hanniabu]

Sorry but I don't trust any nuclear plant in the US to put safety over profits over the long term, especially after all the illogical deregulation done the last 4 years.

There's also already some questions on safety in regards to current plants. They're constantly loosening tolerances and changing the way tests are performed to make otherwise failed tests fall within acceptable limits. Plus the plants are already operating 2x their engineered lifespan. Yeah, no thank you.

[gbrown_]

How much are loosening regulations a concern for nuclear in the US?

Obviously recently general utilities haven't fared well as of late (Texas) or nuclear in the past (e.g. Rocky Flats). But as a foreigner who thinks as far as nuclear power is concerned, the DOE seems to being an OK job as of late. Could you share the specifics of the tests you are referring to?

[hanniabu]

This first link makes me absolutely furious. There's too much to quote from here, but this succicnt excerpt touches on the water test. It goes into more detail in another part of the article. The post has numerous example of very concerning issues.

> When valves leaked, more leakage was allowed — up to 20 times the original limit. When rampant cracking caused radioactive leaks from steam generator tubing, an easier test of the tubes was devised, so plants could meet standards.

https://www.nbcnews.com/id/wbna43455859

> The proposal comes as most of the nation’s nuclear power plants, which were designed and built in the 1960s or 1970s, are reaching the end of their original 40- to 50-year operating licenses. Many plant operators have sought licenses to extend the operating life of their plants past the original deadlines, even as experts have warned that aging plants come with heightened concerns about safety.

https://www.nytimes.com/2019/07/17/climate/nrc-nuclear-inspe...

> The nuclear industry is also pushing the NRC to cut down on safety inspections and rely instead on plants to police themselves. The NRC “is listening” to this advice, the Associated Press reported last month. “Annie Caputo, a former nuclear-energy lobbyist now serving as one of four board members appointed or reappointed by President Donald Trump, told an industry meeting this week that she was ‘open to self-assessments’ by nuclear plant operators, who are proposing that self-reporting by operators take the place of some NRC inspections.”

https://newrepublic.com/article/153465/its-not-just-pork-tru...

[gbrown_]

Thank you for the detailed and insightful reply!

[philipkglass]

The Union of Concerned Scientists has posted a great blog series "Role of Regulation in Nuclear Plant Safety." It's written by Dave Lochbaum, a degreed nuclear engineer who worked at American nuclear plants for 17 years. I think it's a better overview of NRC action and plant safety than any one incident. I've collected all the links here.

Series introduction: https://allthingsnuclear.org/dlochbaum/role-of-nuclear-regul...

Flooding at Nine Mile Point: Regulation and Nuclear Power Safety #1 https://allthingsnuclear.org/dlochbaum/flooding-at-nine-mile...

Three Mile Island Intruder: #2 https://allthingsnuclear.org/dlochbaum/three-mile-island-int...

Empty Pipe Dreams at Palo Verde: #3 https://allthingsnuclear.org/dlochbaum/empty-pipe-dreams-at-...

Yankee Rowe and Reactor Vessel Safety: #4 https://allthingsnuclear.org/dlochbaum/yankee-rowe-and-react...

Flooding at a Florida Nuclear Plant: #5 https://allthingsnuclear.org/dlochbaum/flooding-at-a-florida...

Containment Design Flaw at DC Cook Nuclear Plant: #6 https://allthingsnuclear.org/dlochbaum/containment-flaw-at-d...

Pipe Rupture at Surry Nuclear Plant Kills Four Workers: #7 https://allthingsnuclear.org/dlochbaum/pipe-rupture-at-surry

Anticipated Transient Without Scram: #8 https://allthingsnuclear.org/dlochbaum/anticipated-transient...

Naughty and Nice Nuclear Nappers: #9 https://allthingsnuclear.org/dlochbaum/naughty-and-nice-nucl...

Breaking Containment at Crystal River 3: #10 https://allthingsnuclear.org/dlochbaum/breaking-containment-...

Fatal Accident at Arkansas Nuclear One: #11 https://allthingsnuclear.org/dlochbaum/fatal-accident-at-ark...

[DennisP]

I'm fine with rational regulation and good safety inspections. Here's an example of a regulatory framework that needed reform:

Several years ago I got to attend a meeting between a bunch of people from advanced nuclear startups, and a former head of the NRC. The startup people said their biggest problem was that the NRC required near-complete blueprints before they would even look at the design. Then they would give a flat yes or no. If yes then you still had just a paper reactor, and if no then you were out of business.

Getting to that point required several hundred million dollars. That's a pretty difficult environment for investors. They said just a more phased process would help a lot. The NRC person was unsympathetic, said it wasn't the NRC's job to help develop new nuclear technology, and was uninterested in climate change.

Fortunately Congress has gotten involved since then and things seem to be improving.

[dtwest]

I live near one too, I'm not sure if I should be impressed that disaster was averted in 2002 or if I should be concerned how close things got:

https://en.wikipedia.org/wiki/Davis%E2%80%93Besse_Nuclear_Po...

It would be nice to hear from someone who is more knowledgeable on the subject than myself.

[partingshots]

If an accident almost happened in 2002, then the probability only increases as time goes on.

I personally wouldn’t feel safe, in the long run, buying a house or living near an aging nuclear power plant.

[akiselev]

> I am open to specific proposals for reducing regulations in the nuclear sector if there are regulations that impose additional process overhead, don't actually serve a purpose, and survive only from inertia. I wouldn't be surprised to hear that there are some of these. But I've been discussing nuclear power for 20+ years, starting back on Usenet, and specific proposals are much less common than generic "get rid of red tape" bluster.

Some specific proposals would be to put a minimum nuclear fuel limit on the existing nuclear power plant regulations and create a new class with loosened containment requirements for active reactor designs that are passively safe by nature. Existing regulations are written around reactor designs that hold thousands or tens of thousands of kilograms of nuclear fuel that they have to moderate and keep in check. This is clearly not a viable option for nuclear long term against natural gas and renewables due to the overwhelming cost of manpower and materials which scales poorly. The regulatory overhead, transportation, and storage costs on that much radioactive fuel alone is prohibitively expensive, so we really need to focus on making progress in powered nuclear fission reactors which are impossible under the current regulatory regime.

Designs like the nuclear lightbulb - studied and tested by UTC under a NASA Mars program contract in the late 60s/early 70s - take tens of kilograms of fuel and heat & compress it till it reaches criticality at hundreds of atm and thousands of degrees. Any failure in the system causes a loss of pressure and the core returns to subcritical; even in a worst case scenario like a conventional bomb exploding in the reactor chamber, it would be a minor incident on the level of Three Mile Island. There are many tweaks that have been theorized but untested that would make the reactor even safer. However, any design like this requires regular maintenance of the reactor and completely different levels of containment that are either prohibitively expensive or impossible right now.