Traditional pressurized water reactors have their water under a pressure of 150 atm. A stovetop pressure cooker has a pressure of 2 atm. Sometimes pressure cookers explode, and it's not pretty. Now take that, multiply by 75, and make sure it's safe. There's only one way to do that: very thick steel walls. Walls that can only be made with huge forging presses, like in this eye-popping quote [1]
Westinghouse says that the minimum requirement for making the largest AP1000 components is a 15,000 tonne press taking 350 tonne ingots.
There's currently no forge of this size in the US. There's one of 15000 t, but it can only take ingots of 175 t, half of what AP1000 needs.
> Traditional pressurized water reactors have their water under a pressure of 150 atm. A stovetop pressure cooker has a pressure of 2 atm. Sometimes pressure cookers explode, and it's not pretty. Now take that, multiply by 75, and make sure it's safe. There's only one way to do that: very thick steel walls. Walls that can only be made with huge forging presses, like in this eye-popping quote [1]
This is all just as true about steam pressure in coal power plants. In fact, we now build coal power plants that work with supercritical steam, at 220+ atmospheres.
No, because if a coal plant springs a leak, if you are really unlucky a worker might die from a steam explosion. If a nuclear plant springs a leak the, if you are lucky, reactor containment is irradiated with high level waste, resulting in tens of billions of dollars worth of clean up liabilities. If you are unlucky you leak high level waste into the environment.
Coal plants don't irradiate their steel with neutron radiation either, nuclear plants do, and it changes the material properties of the reactor structure over time.
Engineering is all about designing stuff that will break under specific situations. 150ATM with a safety factor of 2 or more needs to be stronger than 220ATM with a safety factor of 1.
This is one of the reasons nuclear power plants have relatively low power plant efficiency, they want more headroom before stuff breaks.
K-19 is an example of a loss of coolant event due to failure of a pipe, resulting in 22 deaths. (Not civilian, but it's an example of the forces at play- civilian reactors have more layers of protection of course).
Not so great if you have to price insurance against such accidents into your operating costs; while competing against other means of electricity generation.
Three mile island is believed to have caused between 0 and 2 deaths from very low level radiation exposure to the general population. Better cancer treatments means this could very well be 0, but we don’t actually know.
You couldn’t confirm any deaths if the expectation was 2,000 deaths from cancer either. Even for cancers that are highly correlated with specific causes an environmental risk could have caused the original cell’s mutation(s).
Interesting. I see that 'subsidized' renewables are broken out separately from non-subsidized in one of the charts, are there similar subsidies for conventional energy sources?
that's largely a regulatory and volume issue, as most post-three-mile-island safety improvements have been driven by fear rather than need, and as nuclear has been stigmatized to the point we're still recovering from brain drain to Computer Stuff
there was a time nuclear was too cheap to meter. obviously we can't get that back, but it's likely that a nuclear-friendly environment lasting a decade or two can cut that levelized cost to half or less
There has never been a time nuclear was too cheap to meter, that is an urban legend spread by nuclear proponents.
> By the mid-1970s, it became clear that nuclear power would not grow nearly as quickly as once believed. Cost overruns were sometimes a factor of ten above original industry estimates, and became a major problem. For the 75 nuclear power reactors built from 1966 to 1977, cost overruns averaged 207 percent. Opposition and problems were galvanized by the Three Mile Island accident in 1979.[46]
> Over-commitment to nuclear power brought about the financial collapse of the Washington Public Power Supply System, a public agency which undertook to build five large nuclear power plants in the 1970s. By 1983, cost overruns and delays, along with a slowing of electricity demand growth, led to cancellation of two WPPSS plants and a construction halt on two others. Moreover, WPPSS defaulted on $2.25 billion of municipal bonds, which is one of the largest municipal bond defaults in U.S. history. The court case that followed took nearly a decade to resolve.[47][48][49]
> Eventually, more than 120 reactor orders were cancelled,[50] and the construction of new reactors ground to a halt.
> [..]
> The failure of the U.S. nuclear power program ranks as the largest managerial disaster in business history, a disaster on a monumental scale … only the blind, or the biased, can now think that the money has been well spent. It is a defeat for the U.S. consumer and for the competitiveness of U.S. industry, for the utilities that undertook the program and for the private enterprise system that made it possible.[53]
Or as, Hyman Rickover also called: "Father of the Nuclear Navy" said:
> An academic reactor or reactor plant 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 very quickly.
> - (6) It is very flexible in purpose (’omnibus reactor’).
> - (7) Very little development is required. It will use mostly off-the-shelf components.
> - (8) The reactor is in the study phase. It is not being built now.
> On the other hand, a practical reactor 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-reactor 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-reactor designer errs, he wears the mistake around his neck; it cannot be erased. Everyone can see it.
> The academic-reactor 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-reactor designer must live with these same technical details. Although recalcitrant and awkard, 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 reactor 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 reactors 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 reactors, humbled by their experience, speak less and worry more.
tl;dr. "too cheap to meter" is just a well-known turn of phrase to point to the fact that nuclear is inherently affordable over time if you control for certain factors.
i acknowledged in my comment that "too cheap to meter" isn't a realistic expectation for a modern plant, and made the point that nuclear can be _more affordable than it is now_. for further technical reading you can start with https://world-nuclear.org/our-association/publications/onlin...
The vast majority of nuclear power plants were built before three mile island[1] and the accompanying increases in regulation. The point is, even the supposedly "unsafe" nuclear plants are still vastly safer than most energy sources.
You're correct about the infrastructure needs to construct pressure vessels. That's a large part of why nuclear plants were cheaper when built at scale during the 1960s and 70s. It's a lot easier for heavy industry to recoup the investment of building a heavy press if they have an order of 40 pressure vessels instead of 4.
1. Which, by the way, resulted in no radiation exposures or lasting exclusion zone.
The effects on the population in the vicinity of Three Mile Island from radioactive releases measured during the accident, if any, will certainly be nonmeasurable and nondetectable. During the course of the accident, approximately 2.5 million curies of radioactive noble gases and 15 curies of radioiodines were released. These releases resulted in an average dose of 1.4 mrem to the approximately two million people in the site area.
This average dose is less than 1 % of the annual dose from both natural background radiation and medical practice. The 1.4-mrem dose may also be compared to differences in annual doses in background radiation from living in a brick versus a frame house, an additional 14 mrem/yr; or living in the high altitude of Denver rather than in Harrisburg, an additional 80 mrem/yr.
The effect of this total dose, averaged over the population in the site area, will be to produce between none and one additional fatal cancer, and between none and one and a half total (fatal and nonfatal) cancers, over the lifetime of the population. In comparison, approximately a half million cancers are expected to develop from all other sources during this same lifetime.
I don't know if the previous commenter was saying all two million people in the area are black, but they do seem to be considered in this Three Mile Island Report volume 1[1], page 153.
This is probably not true. Most studies showed no significant increase in radioactivity at all outside the plant. Some very motivated anti-nuclear groups argued otherwise, but... I guess it depends on who you want to believe.
Is it really true that the forging of the pressure vessel is a significant portion of the billions of dollars it costs to build a nuclear power plant? As your link explains, there are plenty of forges capable of pressing the required ingot size - located in the places that have modern steel fabrication capability. The US doesn’t have these presses because the US doesn’t have modern steel plants - not because the presses are super rare.
Safety costs money.
Traditional pressurized water reactors have their water under a pressure of 150 atm. A stovetop pressure cooker has a pressure of 2 atm. Sometimes pressure cookers explode, and it's not pretty. Now take that, multiply by 75, and make sure it's safe. There's only one way to do that: very thick steel walls. Walls that can only be made with huge forging presses, like in this eye-popping quote [1]
There's currently no forge of this size in the US. There's one of 15000 t, but it can only take ingots of 175 t, half of what AP1000 needs.This is what keeps the costs sky-high.
[1] https://world-nuclear.org/information-library/nuclear-fuel-c...