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Nuclear - Blog Posts
I've recently been seeing this article making rounds around this website and particularly people misusing this very cool advancement to imply that modern nuclear reactors are "unsafe" or "dangerous", which is partially due to the just blatantly bad journalism on display here.
The accomplishment of this new reactor is definitely exceptionally impressive but I think that news websites (Even ones specializing in science) have been mischaracterizing the reactor as "meltdown-proof" which is just - wrong? and implies that current reactors are just begging to meltdown.
The cool thing about this new reactor is that its passively cooled, but that doesn't mean its INVULNERABLE to nuclear meltdowns, for example the Chernobyl meltdown happened completely independently of whether it was cooled passively or not.
In fact, passive cooling would only pose an advantage in situations where ALL pumps and backup pumps break and the core doesn't get coolant pumped to it. That's happened exactly once: in Fukushima and only after a literal tsunami hit it, and there's no reason to think that the passive Helium coolant in this new reactor wouldn't also just break. Fukushima happened because of corruption in regulation, preventing suitable defenses against this exact thing from getting built, not because of unsafe reactor design.
There's also some articles like this one which talk about the new reactor being "self-regulating" which is true, but misses the point that the vast majority of nuclear reactors in service today are also stable in the exact same way. Negative feedback loops are a HUGE part of reactor design, the most popular reactor design today is the Pressurised Water Reactor (PWR) which is incredibly stable - PWRs just truly hate increasing (or decreasing) energy output.
Most nuclear reactors today are already incredibly safe, even if you had complete control over a nuclear reactor it would be effectively impossible to cause a meltdown on purpose - both the physics of the system and the thousands of automated components would beat the ever loving shit out of any hope of trying to do so.
Articles like these just turn this impressive achievements into a kind of fearmongering over the "dangerous" nuclear reactors currently being used. The fact is that nuclear reactors are incredibly safe, PWRs are an incredible feat of engineering genius and its a genuine shame that the general public isn't aware of how much care goes into their design and safety, let alone how useful and essential they are in our electrical systems.
Modern nuclear reactors are clean, they are safe, and they are vital to a healthy energy grid in the post-fossil-fuel future.
A really good read I highly recommend is Colin Tucker's How To Drive A Nuclear Reactor. He's very clear and very frank with the workings and reality of nuclear power today.
Ladies and gentlemen, this is why I'm pro-nuclear reactors. Seriously, stop bringing up Fukushima and Chernobyl for reasons why we should demonize this energy source. Accept the problem is the coal and fossil fuels and start replacing them with nuclear reactors, solar panels, hydropower plant, and wind turbines. Stop letting these freak accidents scare you into avoiding nuclear as an option because nowadays with the safeguards we have in place at modern-day reactors, the chances of a disastrous meltdown happening like that are so astronomically low that it may as well be zero. You want clean energy? Go nuclear and maybe we might actually have the chance to reverse some of the damage we have brought upon the planet we live on.
Saw my first reactor core. I am a changed woman
That probably explains why I write magic the way I do.
Honestly, the fact that terry Pratchett has experience around nuclear power makes so much sense once you realize what magic is standing as a metaphor for in the discworld. Like, look at this fucking quote from going postal:
"That's why [magic] was left to wizards, who knew how to handle it safely. Not doing any magic at all was the chief task of wizards—not "not doing magic" because they couldn't do magic, but not doing magic when they could do and didn't. Any ignorant fool can fail to turn someone else into a frog. You have to be clever to refrain from doing it when you knew how easy it was. There were places in the world commemorating those times when wizards hadn't been quite as clever as that, and on many of them the grass would never grow again."
Like... It feels incredibly obvious what he's talking about once you know the context.
Megadeth! Interpretación de la portada de "For Sale". Gracias Yago!! Hecho en @thehowltattoo #metalhead #megadeth #megadethfans #rattlehead #davemustaine #metal #trashmetal #nuclearbomb #nuclear #forsale #peaceforsale #colortattoo #newschooltattoo #neotraditionaltattoo #madridtattoo #spaintattoo #jairock #jairocktattoo #jairockfernandez #ink #inked #inkedup #metaltattoo #skulltattoo #skull #thehowltattoo
NUCLEAR REVAMP: R20bn life extension of Koeberg power station poses significant risks for South Africa.
Weird Magnetic Behavior in Space
In between the planets, stars and other bits of rock and dust, space seems pretty much empty. But the super-spread out matter that is there follows a different set of rules than what we know here on Earth.
For the most part, what we think of as empty space is filled with plasma. Plasma is ionized gas, where electrons have split off from positive ions, creating a sea of charged particles. In most of space, this plasma is so thin and spread out that space is still about a thousand times emptier than the vacuums we can create on Earth. Even still, plasma is often the only thing out there in vast swaths of space — and its unique characteristics mean that it interacts with electric and magnetic fields in complicated ways that we are just beginning to understand.
Five years ago, we launched a quartet of satellites to study one of the most important yet most elusive behaviors of that material in space — a kind of magnetic explosion that had never before been adequately studied up close, called magnetic reconnection. Here are five of the ways the Magnetospheric Multiscale mission (MMS) has helped us study this intriguing magnetic phenomenon.
1. Seeing magnetic explosions up close
Magnetic reconnection is the explosive snapping and forging of magnetic fields, a process that can only happen in plasmas — and it's at the heart of space weather storms that manifest around Earth.
When the Sun launches clouds of solar material — which is also made of plasma — toward Earth, the magnetic field embedded within the material collides with Earth's huge global magnetic field. This sets off magnetic reconnection that injects energy into near-Earth space, triggering a host of effects — induced electric currents that can harm power grids, to changes in the upper atmosphere that can affect satellites, to rains of particles into the atmosphere that can cause the glow of the aurora.
Though scientists had theorized about magnetic reconnection for decades, we'd never had a chance to study it on the small scales at which it occurs. Determining how magnetic reconnection works was one of the key jobs MMS was tasked with — and the mission quickly delivered. Using instruments that measured 100 times faster than previous missions, the MMS observations quickly determined which of several 50-year-old theories about magnetic reconnection were correct. It also showed how the physics of electrons dominates the process — a subject of debate before the launch.
2. Finding explosions in surprising new places
In the five years after launch, MMS made over a thousand trips around Earth, passing through countless magnetic reconnection events. It saw magnetic reconnection where scientists first expected it: at the nose of Earth's magnetic field, and far behind Earth, away from the Sun. But it also found this process in some unexpected places — including a region thought to be too tumultuous for magnetic reconnection to happen.
As solar material speeds away from the Sun in a flow called the solar wind, it piles up as it encounters Earth's magnetic field, creating a turbulent region called the magnetosheath. Scientists had only seen magnetic reconnection happening in relatively calm regions of space, and they weren't sure if this process could even happen in such a chaotic place. But MMS' precise measurements revealed that magnetic reconnection happens even in the magnetosheath.
MMS also spotted magnetic reconnection happening in giant magnetic tubes, leftover from earlier magnetic explosions, and in plasma vortices shaped like ocean waves — based on the mission's observations, it seems magnetic reconnection is virtually ubiquitous in any place where opposing magnetic fields in a plasma meet.
3. How energy is transferred
Magnetic reconnection is one of the major ways that energy is transferred in plasma throughout the universe — and the MMS mission discovered that tiny electrons hold the key to this process.
Electrons in a strong magnetic field usually exhibit a simple behavior: They spin tight spirals along the magnetic field. In a weaker field region, where the direction of the magnetic field reverses, the electrons go freestyle — bouncing and wagging back and forth in a type of movement called Speiser motion.
Flying just 4.5 miles apart, the MMS spacecraft measured what happens in a magnetic field with intermediate strength: These electrons dance a hybrid, meandering motion — spiraling and bouncing about before being ejected from the region. This takes away some of the magnetic field’s energy.
4. Surpassing computer simulations
Before we had direct measurements from the MMS mission, computer simulations were the best tool scientists had to study plasma's unusual magnetic behavior in space. But MMS' data has revealed that these processes are even more surprising than we thought — showing us new electron-scale physics that computer simulations are still trying to catch up with. Having such detailed data has spurred theoretical physicists to rethink their models and understand the specific mechanisms behind magnetic reconnection in unexpected ways.
5. In deep space & nuclear reactions
Although MMS studies plasma near Earth, what we learn helps us understand plasma everywhere. In space, magnetic reconnection happens in explosions on the Sun, in supernovas, and near black holes.
These magnetic explosions also happen on Earth, but only under the most extreme circumstances: for example, in nuclear fusion experiments. MMS' measurements of plasma's behavior are helping scientists better understand and potentially control magnetic reconnection, which may lead to improved nuclear fusion techniques to generate energy more efficiently.
This quartet of spacecraft was originally designed for a two-year mission, and they still have plenty of fuel left — meaning we have the chance to keep uncovering new facets of plasma's intriguing behavior for years to come. Keep up with the latest on the mission at nasa.gov/mms.
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