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Nodraak

164 karma · joined April 28, 2017

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Nodraak··on Solar and battery to make up 81% of new US electric-generating capacity in 2024
> "As of early September 2022, 32 of France's 56 nuclear reactors were shut down"

This is cherry picking. Look at the 10 years, or even lifetime, average availability. It's 90 or 95%. The reason for this bad number is because of delayed maintenance due to COVID.

> "serious consequences for power plant cooling systems, as the drought reduced the amount of river water available for cooling."

The reduction of power output of French nuclear was something like 0.30%. You read that right. So I would call "serious consequences" a blatant lie.

Nodraak··on Nuclear Power Is the Answer to Global and Environmental Energy Woes
> one of the plant regularly leaks radioactive material

Please share numbers demonstration health hazards. For ex, bananas are radioactive. Should we outlaw bananas?

> rivers are getting too hot to cool down nuclear plants correctly

That's wrong. In 2022, the power output had to be reduced by 0.18% (not a typo) (https://twitter.com/energybants/status/1645696906327388160). In addition, Nuclear plants can work even in the desert: https://en.wikipedia.org/wiki/Palo_Verde_Nuclear_Generating_...

> nuclear plants are very unreliable

That's also wrong. Please share numbers. Nuclear has a load factor of 95% and its down time can be scheduled (maintenance). Wind has a load factor of 30-40% (and output is unpredictable), solar has a load factor of 20%, hydro requires mountains.

> the government wants to simplify control organism and laws around building new plants

When controls are too tight, nuclear is too slow ; when controls are too loose, nuclear is dangerous. Face je gagne, pile tu perds.

The goal is less CO2, and for that any low carbon energy source is good.

Nodraak··on Show HN: I built an autopilot for the lunar lander game
Nice auto pilot! Very basic, but works well enough.

In the real world, you would derive physics equations (acceleration -> velocity -> position), add constraints and then solve everything to obtain an optimal trajectory (mostly in term of fuel, but you can add other constraints too, for ex due to radar-ground or Antenna-Earth visibility). I wrote a blog post about Apollo's algorithm: https://blog.nodraak.fr/2020/12/aerospace-sim-2-guidance-law... (Described in the second section ; the first section is about a naive algorithm similar to yours that in the end did not work as well as I wanted).

Also, thanks for the code, I wanted to do the same, but lost motivation when I could not really expose in a satisfying way the internal state out of these JS modules (it's not complicated in the end, but I'm simply not a frontend dev ; and I wanted to avoid forking and monkey patching everything and simply adding some JS code throught the console or something).

Nodraak··on France looks into increasing uranium enrichment capacity
Please look at yearly averages to avoid cherry picking.

Maintenance is planned every autumn to make sure that all the nuclear plants work when they are needed, ie. during winter.

Nodraak··on France looks into increasing uranium enrichment capacity
It is not exactly increasing enrichment capacity, it seems it's more complicated than than. From https://twitter.com/TristanKamin/status/1579828412474351616, "UTS" is basically a tradeoff between enriching at the same level more uranium VS enriching to a higher level the same amount of uranium.

About your "fun fact": I don't claim that everything is perfect, but except from going back to the stone age, nuclear is by any measure the least worst option.

Nodraak··on CERN drafts plans to idle accelerators due to Europe’s energy crunch
> because of massive defects or barely producing due to a lack of cooling water

This is false, and not the reason for the (currently) low load factor of nuclear.

Most reactors are off for maintenance, like they are each year in autumn, in order to be ready for the peak demand that winter is. This year might be slightly worse, but it's not unusual at all.

There is also no lack of cooling water. There is only a law that was set many years ago that can be changed without any impact on the safety of the reactors, and this law is limiting only for a few reactors a few days each year. Very anecdotal.

Nodraak··on How Bad Europe’s Energy Crisis Is
> nuclear is demonstrably not working well

You are jumping to this conclusion way to fast.

First, you are cherry picking: you should look at the yearly load factor, not a random day and time of the year when it supports your argument. And you will find that nuclear has the highest load factor of all, 80-90%, while solar/PV will never be above 30-40% (because of physics, you can not change that).

Second, and since I just demonstrated that on a yearly timeframe nuclear works very well, the right question to ask is: why are there so many nuclear plants offline right now? The answer is quite simple, and is due to one of the advantage of nuclear: you can choose when to switch it on or off, for ex to perform maintenance. So, when is the best time to perform maintenance? Answer: just before the peak load, which happens in winter (Mondays around 8 AM in January, to be more precise), so you switch nuclear off in autumn, ie now. It's actually a good news that the load factor of nuclear is so low right now, it means that nuclear will be ready and will work well in a couple of months when we will need it the most.

> Currently Germany is exporting lots and lots of energy

Again, cherry picking, show me the yearly stat. But actually the only comment I will make here is about the criteria you are using: is exporting a lot of energy a good thing? I would say it depends. High variability is bad, it makes the grid unstable. I would rather have low and steady import/export rather than big swings. Exercise for the reader: what allows you to have steady production of electricity (nuclear, hydro, solar, wind, ...)?

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We need more nuclear. Simply because that's the only low carbon, controllable option that currently exists (hydro needs mountains, fossils are high carbon, solar/wind are intermittent)

Nodraak··on NASA Is Launching a New Telescope That Could Offer Some Cosmic Eye Candy
Small precision, because the title of the article is wrong:

JWST is a joint NASA–ESA–CSA project and is actually launched by ESA.

Nodraak··on One man’s fight for the right to repair broken MacBooks
Hey! Jumping in, because I'm learning German: do you have other suggestions appart from MaiLab?
Nodraak··on Florida state of emergency with millions of gallons of “radioactive wastewater”
TL;DR: eating 1 kg of phosphogypsum each day yields 36 mSv/year. Conclusion: very very far from life-threatening ; nobody is going to die or get cancer because of this.

Oh God. This is Fukushima radioactive waters all again. I'm pissed: global warming is serious, and nuclear is our best bet. We dont need this fear-mongering non sense.

Anyway, let's get to the facts and see how radioactive and dangerous this thing actually is. Methodologie from https://en.wikipedia.org/wiki/Banana_equivalent_dose, section "Source of radioactivity".

Here is the data:

    1. Central Florida phosphogypsum averages 26 pCi/g radium
    2. Radium: 10**-7 Sv/Bq
This gives: 26 pCi/g radium * 3.7 * 10**10 Bq/Ci * 10**-7 Sv/Bq (radium) = 0.100 mSv per Kg of phosphogypsum So, if someone eats 1 kg of phosphogypsum per day, that would be 0.100 * 365 = 36 mSv/year.

Background dose is 5-10 mSv/year, a plane pilot or X-Ray machine operator gets around 25-50 mSv/year, an astronaut something like 500 mSv/year.

So, eating 365 kg per year will yield a higher than background dose, but nothing dangerous. I mean, it's probably dangerous to eat so much of this chemical stuff, but not because of radioactivity.

Sources:

    1. https://web.archive.org/web/20150219224641/http://www1.fipr.state.fl.us/PhosphatePrimer/0/684AE64864D115FE85256F88007AC781
    2. https://web.archive.org/web/20121026093251/https://www.epa.gov/rpdweb00/docs/federal/520-1-88-020.pdf - Page 156 and following ; p175 for Radium
    3. https://en.wikipedia.org/wiki/Phosphogypsum
Nodraak··on A new chapter – full-time working from a van in a forest
This sounds very illegal. From what I know, in France the notice period is 1 month if it is "meublé", or 3 months if the appartment is empty.

Edit: actually, I just checked and that's for tenants. If the landlord wants to break the contract to sell the property, it's 3 months for "meublé", 6 months otherwise.

Nodraak··on The Armed Forces Officer Chapter Twenty: Writing and Speaking (1950)
For anyone in Germany (or any country which is blocked by this website), here is the raw html. Save it and open it with your favorite web browser :) http://paste.awesom.eu/Y36k
Nodraak··on Why is the Fessenheim 2 nuclear power plant closing in France?
> Afaik originally the life-span for most reactors of that kind was 40 years

That's a lie, or at least an unprecise statement, mostly shared by the anti-nuclear who are looking for a reason to close reactors.

In France, reactors were designed to work for 40 without any major checkup ; and after 40 years, without any decommission deadline planned in advance, as long the "visite décennale" (in-depth inspection every 10 years) does not discover any major issue. So a reactor can totally work for 60, 70, 80, or even more.

Nodraak··on Sensors detect rise in nuclear particles on Baltic Sea
The original data seems to be available at [^1] but I dont see any spike around the 22-23 of June ... Let's wait to know more before saying anything stupid (looking at you Greenpeace)

[^1] https://www.stuk.fi/aiheet/sateily-ymparistossa/sateilytilan...

Nodraak··on Ask HN: What is your blog and why should I read it?
I am a (aerospace) software engineer. I you wonder what trajectory the Apollo missions followed to go to the Moon, you can read my article about it: https://blog.nodraak.fr/2019/06/free-return-trajectory-1-fly...
Nodraak··on Verlan: French slang that inverses words
While I dont think it is specific to a region, it is probably specific to an age: verlan is quite used among late teens / young adults, while Javanais is more used by childs / young teens. I used to speak Javanais with my sisters as a way to speak without our parents understanding (hopefully!).

It is not really a "slang", but I thought it was similar and worth sharing

Nodraak··on Verlan: French slang that inverses words
Other French slang: Javanais https://en.wikipedia.org/wiki/Javanais
Nodraak··on Diamonds Keep Getting Cheaper
To save other people a clic: "Birefringence is the optical property of a material having a refractive index that depends on the polarization and propagation direction of light." https://en.wikipedia.org/wiki/Birefringence
Nodraak··on The Tyranny of the Rocket Equation (2012)
Indeed, sorry. I focused on "higher up" while the important part was "gravity well"
Nodraak··on The Tyranny of the Rocket Equation (2012)
It's not only about altitude (going to space is easy), it's also about horizontal velocity (staying in space is hard: 8 km/sec is a lot).

I dont recall the exact number, but I think that altitude is 50% of the energy, the other 50% is horizontal velocity. So building a rocket on top of the Everest would save us maybe 5% (10 km vs 100 km altitude), that's not much

Nodraak··on Show HN: HTTP Mock – Intercept, debug and mock HTTP(S) with zero setup
Would not be able to exactly explain the features and differences, but https://mitmproxy.org/ is a similar project you might be interested in.
Nodraak··on Fukushima: Japan will have to dump radioactive water into Pacific, minister says
Sorry for misunderstanding getting away with murder, I'm not a native english speaker. Thank you for the denifition.

Not sure he died because of Fukushima: https://www.forbes.com/sites/jamesconca/2018/09/06/no-the-ca....

Anyway, we are discussing one case. Nobody died during the crisis and after 8 years there is only this case, and this is the second worst nuclear disaster. I am not saying that nuclear is the best, but it is way safer than how people think it is. And definitly way safer than other ways of producing electricity.

Nodraak··on Fukushima: Japan will have to dump radioactive water into Pacific, minister says
Murder? Do you have a source for that? To my knowledge nobody died of radiation at Fukushima.
Nodraak··on Fukushima: Japan will have to dump radioactive water into Pacific, minister says
Very good twitter thread on this thing, with numbers and detailled explanations (in French, sorry): https://twitter.com/TristanKamin/status/1164497983402053634

Check also his other threads, it's a gold mine

Nodraak··on Fukushima: Japan will have to dump radioactive water into Pacific, minister says
> Is a fact that radioactivity kills people

That is false. Or at least very inaccurate.

High levels of radioactivity kills people. In Europe we receive ~5 mS per year, ~10 in the US. Pilots and radiography doctors are at ~20-50 mS/year. Nobody dies because of this. You could double this background radiation and nothing would happen.

So now the question to ask is: how much do they want to dump, and what would be radiation received by the animals and humans around this place. With this we can discuss tradeoff and make an informed decision.

Most importantly, for such important matters[1], you should not run away screaming as soon as you hear the word "radioactive", but rather think and make decisions based on facts, not fears.

[1] In a context of global warming, a way to produce electricity with virtually zero CO2 is pretty cool. Compare France vs Germany: there is a 7x factor in the CO2 produced (dont take my word on that, go check the numbers yourself). Until we know how to store electricity, our best bet is nuclear, not intermittent solar or wind.

Nodraak··on Spacebook: AGI's near Real-Time satellite viewer
To deorbit a satellite, you need an antenna (to receive the command), electricity (working solar panel / battery), working on board computer, fuel, correct attitude determination. So basically you need a full working satellite. As soon as one of these element fails, your satellite is dead. At 10-20 k dollars per kg, you dont want to add another satellite to your already expensive satellite.

Concerning rules, there is some progress, because nobody wants a Kessler syndrome, too much is at stake. For instance, European satellites are launched only if they naturally deorbit in less than 25 years (for LEO, of course. Above a certain height, atmospheric drag is too weak).

Nodraak··on Why the C programming language still rules
The web is such a trashfire

931 requests 113.17 MB / 38.24 MB transferred Finish: 1.68 min DOMContentLoaded: 1.48 s load: 6.54 s

After 50 sec, still loading at more than 1 request per sec... I dont even know what I did to break it. Works fine in incognito mode though

Nodraak··on Librefox, mainstream Firefox with a better privacy and security
As a French, I confirm we put a space before colons. (It's a mistake I often see in English presentations made by French and it drives me crazy)
Nodraak··on Ask HN: Who wants to be hired? (November 2018)
PS: I made a small Twitter thread, with a GIF of a project I am quite proud of (Gali X, an autonomus robot for the french robotic cup). You can take a look and optionally retweet :) https://twitter.com/Nodraak/status/1049261777299673088
Nodraak··on Ask HN: Who wants to be hired? (November 2018)
Industry: (aero)space

Location: Earth

Remote: don't care

Willing to relocate: yes

Technologies: programming (C, python, Asm, Rust, ...), sysadmin and tooling (centos and debian, version control git, monitoring prometheus, jenkins, ...), electronics (pcb design, soldering, robotics, ...)

Résumé/CV: https://cv.nodraak.fr/en.pdf

Email: cf resume

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I am a French engineer, freshly graduated, fascinated by computer science and electronics. I am looking for an internship or first permanent job starting in April 2019. I can relocate anywhere on Earth, but Europe is preferred.

Professional objective: software development or electronic design for space applications (launchers, satellites, spacecrafts, etc).

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