The study of radiation and radioactive materials and it's creation, safety, and applications.

learn more… | top users | synonyms

35
votes
2answers
3k views

Cause for spikes in trinity bomb test

In Richard Rhodes' book, The Making of the Atomic Bomb, I was reading about the Trinity nuclear test. High speed photos were taken and this one is from <1ms after the detonation. The book mentions ...
3
votes
1answer
42 views

Nuclear fission plant loss of coolant accident (LOCA): how bad could it get?

In 1979 the world experienced its first severe nuclear plant accident at Three Miles Island, when TMI-2 underwent a LOCA with devastating consequences for the reactor core. About 50 % of it melted and ...
3
votes
1answer
66 views

Fission bomb: How much of it burns?

I am wondering about measured data on how efficient fission bombs were say the first ones. Since the fission in chain reaction releases large amounts of energy in fractions of a second, I imagine ...
2
votes
1answer
43 views

Why do products of nuclear decay have a lower mass than the original nucleus, when the sum of the mass of its nucleons is larger? [duplicate]

I've just started covering the topic of binding energy in Year 13 at school (final year before University). The definition we've been given of binding energy is that it is the work done when ...
0
votes
1answer
119 views

Nuclear to Electricity Energy Conversion

Currently nuclear power generates heat, which heats water into steam that turns conventional turbines. The energy conversion is as follows: photonic->heat->kinetic->electric This would result in low ...
1
vote
0answers
17 views

Why are heavy elements used in nuclear power plants? [duplicate]

I've seen that the energy produced by breaking an oxygen atom's nucleus is equivalent to burning a LOT of coal, 4.6 million metric tons if I remember correctly. (Crash Course Chemistry) If that is ...
4
votes
1answer
132 views

Why are cooling towers at nuclear power plants shaped the way they are?

The iconic cooling towers at most nuclear power plants are shaped like hyperboloids. Wikipedia mentions that this is because the wide base promotes thin film evaporation and the narrow point ...
1
vote
0answers
20 views

How much water do nuclear plants release as steam? [closed]

I'm not sure if this is the right site, but I was wondering how much water is released by today's nuclear plants during normal operation.
5
votes
3answers
7k views

Would being underwater help survive a nuclear bomb?

If I jump in my pool, on the river near my house knowing that a nuclear bomb, or atomic or H-Bomb exploded around 10 km from my house, would I survive? The way I see it is that water will protect me ...
1
vote
2answers
122 views

Why do people say nuclear fusion is 50 years away? [closed]

This '50 years' number is floating around media pretty consistently, even the ITER road map claims that the first commercial reactor will happen post-2050. But why is that? I understand that there is ...
0
votes
2answers
130 views

Fusion reactors why does size matter?

I've been following articles about fusion recently, and with the ITER project mostly. I have noticed that their view point is they need to build a large scale reactor in order to achieve their goals. ...
-1
votes
2answers
283 views

What is the theoretical wattage output of a Tokamak fusion reactor?

By that I mean the complete radiative wattage of any type of energetic radioactivity or electromagnetic wave or even particle if that's what they output. My purpose is to compare this to the suns ...
0
votes
2answers
191 views

Could a Nuclear Reactor Run (controllably) in Prompt-Critical Mode?

Could a nuclear reactor run (controllably) in Prompt-Critical mode? It would have a much higher power output than a normal nuclear reactor. Could it be controlled by some high-tech material that ...
-1
votes
1answer
45 views

Managing nuclear waste [closed]

Suppose you are trying to dispose of used uranium fuel rods. Once they are cooled and contained in zirconium pods, how would one try and send those pods to the earths core? This is all hypothetical. ...
1
vote
2answers
178 views

The NERVA had to use liquid H2… But why?

The NERVA engine, developed at the late 60ies, was a nuclear thermal rocket developed for vacuum use in space craft. It was supposed to use Liquid Hydrogen, a cryogenic fuel with quite a few issues ...
2
votes
1answer
80 views

Smallest possible size of nuclear reactor [closed]

I recently began playing Fallout 4 and asked myself a question: Would it be possible to build a power armor with todays technology? I did some investigation on servomotors and stuff and came to ...
15
votes
2answers
2k views

How to detect a secret nuclear detonation here on the earth?

How can we know that North Korea and Iran (to name a few) are exploding nuclear weapons if no inspectors have ever been granted access to suspected nuclear sites in these countries? How can we ...
1
vote
2answers
34 views

Nuclear transmutation of radioactive waste using high-energy neutrons

How likely does this work: Accelerate neutrons to as high energy as possible (particle accelerators/ cosmic rays ...) and hit (small samples of) our radioactive waste with it such that it is converted ...
0
votes
2answers
29 views

Can multiple adjacent reactors use neutron reflector walls in common to save mass?

Reactor designs like fission-fragment and some others use large masses of neutron reflectors to attain criticality. (For that matter, the very first pile did too, and in a staggered form rather ...
0
votes
0answers
18 views

Criticality in liquid thorium fluoride reactors

I have been reading up a bit about LFTRs over the past few days. Regarding safety, the argument of the people is that at the bottom of the reactor, there will be a salt plug that will be cooled by air ...
0
votes
1answer
28 views

Stabilizing Radioactive Fission products

So most fission products have very long half-lives. But i noticed that if a neutron is added the half life becomes a fraction of what it originally was, so could this be a possible method of ridding ...
17
votes
2answers
6k views

How would a black hole power plant work?

A black hole power plant (BHPP) is something I'll define here as a machine that uses a black hole to convert mass into energy for useful work. As such, it constitutes the 3rd kind of matter-energy ...
1
vote
1answer
137 views

What is the difference between zero background radiation and field background radiation in Nuclear Physics measurements?

Can someone please explain the difference between these two terms (Zero Background Radiation and Field Background Radiation) used in radiometric prospecting measurements?
29
votes
5answers
7k views

How do control rods work?

I understand the basic idea of nuclear fission: put a bunch of fissionable material together and let the neutrons fly. An atom gets split, kicking out a few more neutrons, which split other atoms, ...
3
votes
1answer
80 views

How does neutron reflection work?

What I mean here isn't what is it used for, but what's actually going on with the reflector. There are a lot of sub questions to this. how much energy is lost in the act of reflection. not ...
4
votes
1answer
106 views

Why would an alpha-beryllium neutron source generating a radioisotope not produce controllable net power?

I have a question. I was looking through the table of nuclides and noticed that the energy needed to produce certain radioisotopes was less than the energy given off by the radioactive decay of that ...
3
votes
4answers
10k views

Why build nuclear reactors on shorelines?

While not directly a physics question, I can't think of forum better capable of answering my question. In discussions over Japan's nuclear reactor situation the observation was made that reactors ...
2
votes
2answers
147 views

Advanced Molten Salt Reactor - Is the concept of designing a reactor that uses spent nuclear fuel to generate power technically feasible?

I was going through the concept of designing a Nuclear Reactor that uses Spent Nuclear Fuel(SNF) to generate power as proposed by Transatomic Power . ...
4
votes
3answers
732 views

Would sea water moderate a nuclear submarine meltdown?

My son asked me: If nuclear submarines get sunk or blown up, what is to stop them going into nuclear meltdown? I thought about it and came to the conclusion that because they're in the sea the ...
2
votes
1answer
161 views

From which height the effect of nuclear bomb will be Greater?

Well I was wondering like during war some of them drop nuclear bomb on ground and then it explode and we see a huge blast which causes so much of destruction but my question is that is it possible ...
6
votes
2answers
262 views

Saturn V F-1 engines and beyond

I read that the F-1 engine from the 1st stage of the Saturn V rocket is the most powerful engine ever created by mankind, delivering ~200 gigawatts of power. Thus, I have got two questions: Will ...
25
votes
5answers
3k views

Is it possible to build a thermoelectric nuclear power plant?

Current nuclear power plants are essentially an enhanced version of a kettle, which seems like a stupidity caused by a lack of other options. We heat the water which turns to steam which rotates the ...
2
votes
0answers
27 views

Is the spontaneous fission-yield curve for 240Pu known?

I have not seen any data for the isotopes produced by spontaneous fission of plutonium. I believe this will be dominated by 240Pu as the major even-numbered isotope produced in reactor operations. I ...
0
votes
2answers
117 views

Nuclear based wireless power?

I would like to ask if there is any Nuclear process which can be used to produce a wireless power ? Is there any nuclear process can be radiate to the environment with no harm to human beings? ...
25
votes
9answers
9k views

Why don't modern spacecraft use nuclear power?

The Voyager 1 & 2 spacecraft launched in 1977 with Plutonium as their source of electricity. 34 years later they claim these two spacecraft have enough power to last them until at least 2020. That ...
14
votes
4answers
2k views

Why can't there be a trap door under nuclear reactors in case of meltdown?

This may be a naive question, but after the Fukushima Daiichi partial meltdown and studying the aftermath of Chernobyl it seems they could be helped by this idea. In Chernobyl, the liquidators that ...
3
votes
11answers
2k views

Can a nuclear reactor meltdown be contained with molten lead?

If lead can absorb or block radiation, would it be possible to pump molten lead into a reactor core which is melting, so that it would eventually cool and contain the radiation? Is there something ...
11
votes
3answers
4k views

why aren't there nuclear powered aircraft?

I know this might sound like more of an engineering question that about physics, and it probably is, but bear with me: i'm still not sure if the answer to my question lies in the physics or in the ...
3
votes
4answers
447 views

Is a Rubbia thorium reactor safer than other modern reactor types?

I keep wondering how a Rubbia thorium reactor would handle a natural disaster of Fukushima level intensity. As I understand it the nuclear chain reaction would stop instantly if the power is cut, but ...
1
vote
1answer
177 views

Radiation level risk: mSV, exposure and current status of chernobyl area

I was watching this two videos from youtube. One is a documentary about Chernobyl disaster: https://www.youtube.com/watch?v=d5vlk_d6hrc Another is a random personal video: ...
0
votes
1answer
148 views

How long remains a boron control rod?

I was wondering today, how long boron control rods remains in a nuclear power plant? When a boron atom absorbs two neutrons, it becomes the unstable isotope boron-12 and and the boron nuclei starts ...
4
votes
2answers
356 views

Another cold-fusion reactor scheme :) Is it feasible?

I have this idea rolling in my head for quite a while, but lately I got really interested to know if it's even remotely feasible. I am complete novice to the field of nuclear engineering and cold ...
7
votes
4answers
6k views

How do you build a nuclear reactor in your garage?

When I came across this link earlier today, I was astounded. Nuclear reactors are immensely complex devices that took scientists years to develop, and are usually housed in huge facilities. The link ...
2
votes
2answers
127 views

Can a nuclear reactor be used as a space-based weapon?

Imagine you have a ship, running on power from a nuclear reactor. We will assume this ship uses some kind of advanced technology that allows nuclear reactors to function in a microgravity environment. ...
44
votes
9answers
18k views

What practical issues remain for the adoption of Thorium reactors?

From what I've read on thorium reactors, there's enormous benefit to them. Their fuel is abundant enough to power human civilization for centuries, their fission products are relatively short-lived, ...
2
votes
0answers
259 views

How big is a nuclear reactor pressure vessel? [closed]

With all the sudden discussion related to Nuclear power, safety, fuel, waste, etc, there's one question whose answer has so far eluded me. How big (height and diameter) is the actual pressure vessel ...
3
votes
2answers
636 views

Why are neutron absorption cross sections high at low incident energy?

For example, U-235 fission cross section looks like this: As I understand it, the resonances peaks correspond to discrete quantum states of the excited compound nucleus. As you go higher, the ...
0
votes
3answers
2k views

Can a glass window protect from heat radiation?

I have been reading in this and found a statement saying : " Glass will not transmit heat radiation.". So now I am confused. If glass won't transmit heat radiation, then why do we feel hot when we sit ...
1
vote
1answer
42 views

Are there other natural reactors than the Oklo mine? Any still active?

Actually my question is more whether any other natural reactor has been found, despite the one at Oklo. And whether there are any known active natural reactors these days. Bonus question: if there ...
0
votes
0answers
54 views

thresholds for Cherenkov radiation visible to the human eye

In pool-type fission reactors, the beautiful Cherenkov radiation from the beta decay of intermediate products seems to be a well-understood phenomenon. I am wondering what some ballpark figures are ...