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Comment by dtagames | Hacker News Reader

This might be a good time to review the number of failed rocket launches we've seen in the last few years.

Now, imagine them with nuclear materials aboard.

Well that's the most obvious way to put FUD out there.

It might be a good time to review the number of failed launches on crew rated rockets (the safety requirements on which are roughly equivalent to the requirements for carrying nuclear material). Particularly ones which led to a loss of crew, as those would correspond most closely to a possible nuclear material release.

It's far less scary, but alas not as convenient for FUD.

I would add it's much easier to protect a small amount of nuclear material from a rocket exploding than to protect a human from a rocket exploding.

Depending on the design, failure during launch can be anywhere from "meh" to "basically high-altitude Chernobyl" — random actinide decay products (and plutonium fuel) are bad, unreacted uranium fuel is mostly a heavy metal hazard rather than a radiation hazard.

(Could be worse, but the Orion drive is currently illegal by treaty and hopefully nobody is dumb enough to use that in Earth's ionosphere anyway).

I remember learning that when they started testing atomic bombs (I think?) the nuclear debris in the air spread basically throughout the whole united states and the government tried to keep quiet about it. Something similar will probably happen here if they mess up with the launch.

Btw, the video I saw was on Veritasium.

I remember that video; the long story short was that a manufacturer of films for photography noticed that their films had spots on them, they initially thought it was defects, but because they had samples prior to testing, they saw an uptick.

But maybe I remember wrong.

Edit: the video in question is [1] and the conpany was Kodak.

[1] https://youtu.be/7pSqk-XV2QM

Not sure about camera film, but there's certainly a need for 'low-background steel' for several applications: https://en.wikipedia.org/wiki/Low-background_steel

Speaking of, one way we verify old wine is through background radiation!

Sounds like the way Columbo would have caught one of the killers on the show.

It was used in "White-Collar" to create a scam!

The thing to remember about that is that we can measure tiny amounts of radiation very cheaply, and tiny amounts are harmless. In fact we are bathed in a constant, but tiny, background level of radiation all the time. Thousands of nuclear weapons were tested all across the world, in the United States, in the Soviet Union, on Pacific Islands, etc, etc. The radiation from that certainly caused a small uptick in the background level of radiation, but it hasn’t actually harmed people.

The main reason that the US was secretive about it was that nuclear weapons were a secret, not because there was a shameful health problem to hide.

Incidentally, the best way to reduce your exposure to radiation is to move away from the mountains and go live at the beach. Mountains are mostly made of granite, and granite always contains small amounts of uranium and thorium which decay to radon gas. Also, live as far away from coal power plants as possible, those things are horrifying.

Background radiation may be unlikely to give an individual cancer whilst still causing cancer across a population. It just isn't possible to attribute the cause. Surely the same is true of fallout from testing and estimates would back that up. It may not be something we worry about as individuals. But it is something that nasa should worry about.

Background radiation is categorically different than ingesting/inhaling radioactive substances with the latter many orders of magnitude more dangerous.

The claim, nuclear testing related increases in radiation exposure not being relevant for public health is probably false. There are only very few studies with dubious reliability. The lifetime increase due to that nuclear testing is estimated to be 4.4 Millisieverts. It would have risen continuously with more surface tests, which got abolished accordingly.

The idea, beaches were a sanctum against radiation is wrong again. Sand is ground down mountains in case you wondered. Some are highly radioactive. But of course, UV light is harmful radiation as well.

We eat bananas all of the time. Bananas are delicious and nutritious, and they are known for containing lots of potassium. Well, some of that potassium is radioactive! It’s not very much radioactivity though. It is an amount which is easily measured, but which is not harmful enough to make eating bananas dangerous. This is true even though the potassium will be used to strengthen your bones and teeth. It will also be distributed to your muscles, red blood cells, skin, etc, etc.

There have not been thousands of nuclear tests.

"""There have been 2,121 tests done since the first in July 1945, involving 2,476 nuclear devices. As of 1993, worldwide, 520 atmospheric nuclear explosions (including 8 underwater) have been conducted with a total yield of 545 megaton (Mt): 217 Mt from pure fission and 328 Mt from bombs using fusion, while the estimated number of underground nuclear tests conducted in the period from 1957 to 1992 is 1,352 explosions with a total yield of 90 Mt.[1]"""

- from opening paragraph of https://en.wikipedia.org/wiki/List_of_nuclear_weapons_tests

[1] https://doi.org/10.1007%2F978-3-662-03610-5_17

The atmospheric tests are the only ones that matter in this context.

Depends on the details; in water, too close to ground water, near ground level and breaching the surface (Operation Plumbbob), and I don't have numbers for those.

But still, thousands of bombs were in fact tested, and the context here is testing a reactor that won't be on Earth at all via a diversion into "we can detect really small levels of radiation".

There's a difference between a lump of uranium metal falling back to earth and a lump of uranium that's been turned into plasma.

The nuclear payload could be treated similar to humans, with eject systems and soft landing built in.

The fuel will only be needed for a lighter craft in deep space. Getting it up with a high reliability rocket (like Falcon 9) significantly decreases risk.

> The nuclear payload could be treated similar to humans, with eject systems and soft landing built in.

In principle yes — even just on the grounds that enriched fuel is expensive — but it's a hard thing to prove in advance, hence all the times humans died in a space mission one way or another.

There have only been 5 instances resulting in 19 fatalities. None were when exiting the atmosphere. 2 were the flawed Space Shuttle on return. Only one other was a flight system, on an experimental craft.

https://en.m.wikipedia.org/wiki/List_of_spaceflight-related_....

Today's rockets are far more reliable, and anything holding nuclear fuel should be the best of the best.

> None were when exiting the atmosphere

Er, Challenger?

What does "meh" mean? Is that english?

"Meh" is a casual response that means "this does not matter much". I don't know that it's proper English by any means, but it is certainly a common colloquialism. A cursory search suggests that it's imported from yiddish.

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

I have never seen it used outside of Hacker News.

It's not an uncommon expression. I searched the term in a chat room my friends (of varying professional backgrounds) have used over the past 5 years. There were about 200 instances of us using the word.

Native English speaker here. It’s an extremely common expression in some regions. The main character of the Emoji movie is named “meh”.

Its Yiddish, but came into popular use because of an episode of the Simpsons.

Reusability helps with long term reliability. You would probably want to avoid launching nuclear material on a new rocket, but a human rated rocket like Falcon 9 would be totally fine.

Well look at the number of missions with RTGs on board and you don't have to imagine, nuclear powered probes and satelites are not unheard of. The soviets also had an entire series of fission powered spy sats way back.

> Once it reaches a safe orbit, the reactor will be turned on.

Fission reactors aren't appreciably more radioactive than rocks you can dig out of the ground until you turn them on. This is something that wouldn't be brought online until the riskiest part of the launch has past.

Uranium that has not been in a reactor is almost nonradioactive and inert. It only gets spicy after you let it go critical for a while, and fission products accumulate.

Any reasonable nuclear-powered craft would not start up the reactor until it's already in a nice, safe, high orbit.

What failed rocket launches? That hasn’t happened in a long while. SpaceX just surpassed their 100th consecutive first-stage launch without any failure. Boosters are super reliable these days.

I'm no engineer, but it sure seems to me like you could either split things up into multiple launches, or potentially manufacture the fuel in orbit, no?

Falcon9 hadn’t had a failure for nearly a decade

Falcon 9 has had more than 200 consecutive successful flights in a row. That is more than double the next most successful, Delta II with 100 in a row.

It also has well over 100 successful landings in a row, while the next closest rocket has 0. (Rocket, not capsule or shuttle, which are all still far lower)

https://en.wikipedia.org/wiki/Soyuz-U

"The rocket had a streak of 112 consecutive successful launches between 11 July 1990 and 5 May 1996"

There is another rocket that has had a few successful landings: Falcon Heavy.

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