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

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1answer
109 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?
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2answers
129 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 . ...
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3answers
569 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 ...
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1answer
91 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 ...
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2answers
231 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 ...
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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 ...
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0answers
20 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 ...
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2answers
111 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? ...
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9answers
7k 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 ...
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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 ...
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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 ...
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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 ...
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4answers
404 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 ...
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2answers
98 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 ...
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1answer
132 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: ...
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1answer
76 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 ...
3
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2answers
315 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 ...
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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 ...
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1answer
108 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. ...
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2answers
111 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. ...
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9answers
17k 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, ...
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0answers
250 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
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2answers
422 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 ...
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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 ...
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1answer
36 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 ...
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0answers
43 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 ...
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4answers
8k 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 ...
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1answer
115 views

What is the relation between the half-time and the line-width of a radioactive nucleus?

Are they inversely proportional to each other? This is the case for the atoms, I think. The problem is that, for those isotopes like uranium 238, the half-time is as long as 4.4 billion years, and ...
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2answers
68 views

How do you measure neutron energy?

I think you can detect a neutron event with a scintillator (neutron to photon), photomultiplier tube (photon to electric signal) system, but how would a fusion neutron's energy (2.45 MeV) be typically ...
3
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3answers
187 views

How to block neutrons

What is a good way to block neutrons and what is the mechanism that allows this? It's my understanding that polyethylene is somewhat effective. Why?
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1answer
177 views

How to calculate scalar neutron flux

I am really confused about the difference between flux and scalar flux. I have a specific question: If we have a parallel neutron beam of strength $\phi_0$ given in neutrons/cm$^2$s, incident on a ...
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1answer
76 views

Would it be possible to “recycle” nuclear warheads into nuclear energy? [closed]

The number of nuclear warheads in the world is estimated (!) to be over 16,000. [0] Surely, this stockpile represents a massive threat to humanity. My question is simple. Can we repurpose these ...
3
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3answers
639 views

If there is a meltdown at the Fukushima reactors, would the control rods melt also?

According to the reports, the shutdown procedures at all the Fukushima reactors were successful, and all the control rods were fully inserted. So - if there was a meltdown, would the control rods ...
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0answers
29 views

Why does U-235 split into barium and krypton in nuclear reactors? [duplicate]

For my chemistry project I have found the typical fission reaction which occurs in nuclear power plants is when nuclear fuel rods are bombarded with neutrons, splitting U-235 into isotopes barium and ...
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1answer
50 views

Why do NNLC and NIST appear to give different values for the mass energy of the deuteron?

There is a problem with data that I've obtained over the internet. Here are the two sources of information from which I'm retrieving my data. NNLC and NIST On NIST, I have read that the mass excess ...
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2answers
151 views

What's the largest mushroom cloud possible from a coffee cup/grenade sized nuclear bomb?

Assuming the coffee cup is $16$oz = $1$lb = $0.4536$kg or $ \sim 450$mL I did a quick comparison to the W54 assuming there was a linear ratio (wishful thinking perhaps), and got it to be around 8m ...
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5answers
4k 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, ...
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2answers
336 views

Is the E-Cat by Andrea Rossi et al. proof that cold fusion can work? [duplicate]

A team of researchers have tested a device (the E-Cat) produced by a team in Italy led by Andrea Rossi and claim that its 'abundant heat production' together with the change in the composition of its ...
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2answers
1k views

Is the E-cat by Andrea Rossi et al. for real?

Does this thing really do what they say? http://www.youtube.com/watch?v=EhvD4KuAEmo If it does, it looks like this will probably be the biggest breakthrough in science ever :)
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1answer
84 views

Use of fission products for electricity generation

Why can't we use fissions products for electricity production ? As far has I know fissions products from current nuclear power plants create enough 'waste' heat to boil water; and temperature ...
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4answers
4k views

Why aren't betavoltaics and alphavoltaics batteries widely used?

Betavoltaic batteries are devices which creates electricity from beta radiation of a radioactive material. Alphavoltaics operate similarly, using alpha radiation. The concept was invented roughly 50 ...
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1answer
550 views

What is the most stable nuclide of an isobar?

From the semi-empirical mass formula, the mass of an atomic nucleus is $$M\left(A,Z\right)=Zm_p+(A-Z)m_n-\frac{E_b(A,Z)}{c^2}$$ I've been told (at first) that for a given mass number $A$, the most ...
2
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1answer
64 views

Why is the D+T fuel inside a pellet in two distintic regions in fusion after compression

Could anyone explain why the D+T inside the pellet is in two distinct regions? And why the center is a lot less dense than the outside region? I have been trying to find answers online but i cant ...
0
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1answer
70 views

The formation of shockwave inside pellets in inertial confinement fusion

In the explanations i have read on the internet about ICF they all explain that the top layer of the pellet or the ablator is heated till it explodes and this produces a reaction force which compress ...
14
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1answer
191 views

Spallation neutron generation and pure U-238 reactors

Main question: Is it possible to achieve net power generation based on linear proton accelerator and U-238 target? In the proposed reactor design there is a proton beam with energy ~10 GeV, and on ...
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2answers
135 views

Is fission reaction considered natural or artificial? [closed]

As I learned, nuclear fission doesn't occur without the control of a human made nuclear reactor, by hitting a neutron to a fissile isotope. Thus, the fission reaction is considedred as a part of ...
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0answers
95 views

Thorium based nuclear reactor [closed]

My question is how thorium works as a radioactive nuclear fuel and what are the special properties of thorium based nuclear reactor.
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2answers
51 views

Explosive energy in a container [closed]

What happens when the explosive energy of a grenade or a bomb is contained in a container, if you will, and no energy can be released through the container in the form of heat or sound etc...? Just ...
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2answers
4k 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 ...