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Making Nuclear Energy Smaller, Cheaper And Safer

npr.org

11–20 of 116 posts

Re: Making Nuclear Energy Smaller, Cheaper And Safer

#11
Although I'm not a big nuclear power fan for various reasons, I'm really happy to see someone approaching it with an eye to realistic safety, modern economics, and compatibility with a renewable-based grid. It'll be interesting to see if this can compete financially with batteries.

Re: Making Nuclear Energy Smaller, Cheaper And Safer

#12
> "My concern about NuScale is that they believe so deeply that their reactor is safe and doesn't need to meet the same criteria as the larger reactors, that it's pushing for lots of exemptions and exceptions," says Edwin Lyman, acting director of the Nuclear Safety Project at the Union of Concerned Scientists

Bit of a red flag there...

Edit:

The article further states: > "Licensing this design is challenging. It's so different from existing plants that regulations must be changed to accommodate it. That worries some watchdogs and critics."

Let's not shoot the messenger here.

If they are regulatory requirements that clearly do not apply to this technology because, e.g. it does not use the regulated parts or technology then fine. But that should be very thoroughly scrutinised and no exception should be granted on the basis that it is safe on paper.

Many requirements are very expensive to meet so I would understand that a private startup tries to minimise the burden. But I think nuclear safety comes first.

Re: Making Nuclear Energy Smaller, Cheaper And Safer

#13

“NuScale's design doesn't depend on pumps or generators that could fail in an emergency because it uses passive cooling. The reactors would be in a containment vessel, underground and in a huge pool of water that can absorb heat. That means that even a reactor that fails would still be safe. "It doesn't require any additional water," says Feldman. "It doesn't require AC or DC power. It doesn't require any operator ac…

Leaks are designed out because the entire reactor vessels are surrounded by a giant swimming pool. The temperature stays low enough because this swimming pool is passively cooled. Lack of relible decay heat[1] cooling caused both Fukushima and three mile island accidents. Having passive decay heat removal usually decreases the probability of core damage by about 100x. 1 https://whatisnuclear.com/decay-heat.html

What happens if the swimming pool leaks ?

Re: Making Nuclear Energy Smaller, Cheaper And Safer

#15
I have a hard time accepting their premise that they are designing for "cheaper" based on that artists rendering (which I assume is based on some real design elements). Curvy roofed buildings and arced cooling ponds are not at all the most cost effective construction methods.

I want truly cheap nuclear that sits in unobtrusive cheap concrete boxes like the old Bell telephone exchange buildings.

Re: Making Nuclear Energy Smaller, Cheaper And Safer

#16

Earlier quoted context omitted.

Leaks are designed out because the entire reactor vessels are surrounded by a giant swimming pool. The temperature stays low enough because this swimming pool is passively cooled. Lack of relible decay heat[1] cooling caused both Fukushima and three mile island accidents. Having passive decay heat removal usually decreases the probability of core damage by about 100x. 1 https://whatisnuclear.com/decay-heat.html

What happens if the swimming pool leaks ?

The pool only needs to function for a few days during/after an accident until heat energy from fission product decay reduces to lower levels. The pool's function is as an accident mitigation measure - and when any accident occurs the reactor enters a "shut down" state. The decay heat energy that needs to be dissipated is much lower than normal reactor operational power output.

Re: Making Nuclear Energy Smaller, Cheaper And Safer

#17
post #11

Although I'm not a big nuclear power fan for various reasons, I'm really happy to see someone approaching it with an eye to realistic safety, modern economics, and compatibility with a renewable-based grid. It'll be interesting to see if this can compete financially with batteries.

>> ... if this can compete financially with batteries.

I don't think there will be competition. With storage costs dropping I don't see why nuclear plants would be any different than solar or wind. If solar+wind can cover current demands, why turn down the reactors? Why not keep them running and charge up some battery capacity for the day that solar+wind isn't enough?

The ideal grid would have all energy sources running constantly at their most efficient, usually 100% rated production, and use batteries to smooth out the load. The reactors wouldn't need to throttle. All that entropy would be pushed to the batteries.

Re: Making Nuclear Energy Smaller, Cheaper And Safer

#18
Their webpage [0] has the construction cost at $3 billion for a ~700 MW reactor. This is about the same as the originally projected cost for the Flamanville EPR with 1600 MW, which now is expected to end up costing ~$10 Billion. Now even if we assume - and thats a big assumption - they really can build the reactor for $3 Billion, that still equals ~$7 Billion in construction costs for a Flamanville sized reactor.

They do not put any number on their operating costs which makes it impossible to calculate the electricity price they need to break even. If there is any information out there it would be appreciated.

[0] https://www.nuscalepower.com/benefits/cost-competitive

Re: Making Nuclear Energy Smaller, Cheaper And Safer

#19

Earlier quoted context omitted.

Leaks are designed out because the entire reactor vessels are surrounded by a giant swimming pool. The temperature stays low enough because this swimming pool is passively cooled. Lack of relible decay heat[1] cooling caused both Fukushima and three mile island accidents. Having passive decay heat removal usually decreases the probability of core damage by about 100x. 1 https://whatisnuclear.com/decay-heat.html

What happens if the swimming pool leaks ?

I mean ... millions of people who barely maintain their homes avoid pool leaks, and when it does leak, it tends to be slow enough that they can call in a professional to fix the problem. Imagine a fastidiously maintained facility ... I think they can probably work it out

Re: Making Nuclear Energy Smaller, Cheaper And Safer

#20
post #9

Earlier quoted context omitted.

Leaks are designed out because the entire reactor vessels are surrounded by a giant swimming pool. The temperature stays low enough because this swimming pool is passively cooled. Lack of relible decay heat[1] cooling caused both Fukushima and three mile island accidents. Having passive decay heat removal usually decreases the probability of core damage by about 100x. 1 https://whatisnuclear.com/decay-heat.html

"Having passive decay heat removal usually decreases the probability of core damage by about 100x." 100x isn't 100% though. 100 of these small reactors has the same risk as one large reactor. Perhaps higher, because like you, everyone goes around saying the risk has been designed out. Though obviously one small reactor going boom is preferable to a big one doing the same.

100% safe is never the metric. Nothing is 100% safe. Every form of energy generation has risks that have to balance the good the energy source brings. Nuclear is nearly unique in that it can produce carbon-free energy (unlike fossil and biomass), continuously for 2 years on end between reloads (unlike wind/solar/coal), and it can be deployed in a wide variety of geographic locations (unlike hydro and geothermal).

The risk is that there are occasionally nuclear accidents: Three mile island and fermi 1 meltdowns, both of which killed zero people. Chernobyl, which killed ~50 from ARS and up to 4,000 early deaths over the next several decades (on top of a few million cancers that would have happened anyway in the population). Fukushima, which killed up to one person. Can anyone name any fatal natural gas explosions? Any hydro dam failures that killed 100,000? How many people per year does coal kill by operating normally (~200,000). We as a society accept certain risks from our energy infrastructure because of all the good we get from it.

Here is a plot of how many thousands of days of life are lost by various things [1]. Note that nuclear is almost ridiculously low. This chart doesn't include the impact of climate change on human lives. Nuclear fission is a climate superpower, and we cannot be justified in neglecting this natural resource because we're afraid of something going boom.

TLDR: A factor of 100x improvement in nuclear safety goes from tiny risk to supertiny. Current plants are already safer than almost everything else we know. Some studies have more people dying from installing solar on their roofs than getting killed by radiation from nuclear fission plants.

[1] https://i.imgur.com/ClgbpA4.png

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