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

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17
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6answers
1k views

Which experiment gave scientists reason to believe nuclear fission/fusion produced energy?

Every piece of knowledge in science has a beginning lying in someone's experiment. I would like to know which experiment gave scientists the reason to believe nuclear fission/fusion existed and was ...
3
votes
1answer
73 views

What decides fission products?

I am learning about nuclear fissions and learned about the fission fragment distribution. It was interesting to see that the fission fragments have unequal masses. I was wondering as to what governs ...
0
votes
1answer
63 views

What kind of research will go in nuclear fusion power once the commercial power plant is designed and implemented? [closed]

once the commercial nuclear power plant is built for electricity production , after this what kind of research does scientists do in nuclear fusion power. Why I am asking this question is ITER is ...
-1
votes
1answer
89 views

Whether nuclear physics or nuclear engineering is suitable for doing research in nuclear fusion? [closed]

I want to do research in making nuclear fusion sustainable for electrical energy production , which field I should choose? and it is worth doing research in fusion now, since many of them are saying ...
6
votes
3answers
136 views

scrap iron for stopping a meltdown

Would it be possible in a Fukushima-style meltdown to halt the process (edit: I mean halting the meltdown process, not the actual nuclear processes) by dumping large amounts of iron into the vessel? ...
2
votes
2answers
186 views

Can Deuterium undergo a nuclear fusion without the presence of Tritium?

I've been reading about fusion fuels for a while now, and I understand that in Lithium-Deuterium fuel, the neutrons from the fission reaction bombard the Lithium to produce Tritium and the D-T ...
-1
votes
1answer
131 views

How many gas centrifuges are needed to build two small nuke within a year? [closed]

imagine this is 1960-70.....a country has nuclear plants already (for peaceful purposes) now if they get the technology of gas centrifuges what things they are going to need for building two small ...
0
votes
1answer
53 views

Algorithm for distribution of radiation

Unstable atomic nuclei will spontaneously decompose to form nuclei with a higher stability. What is the algorithm for deciding what sort of it is? (alpha, beta, gamma, etc. Also, given that alpha and ...
16
votes
2answers
659 views

Is there a sound theoretical argument against inner-shell induced nuclear chain reactions?

There is a claim often made about cold fusion, that it is excluded theoretically. The main theoretical argument is that electronic energies are too low to overcome the Coulomb barrier, since d-d ...
7
votes
3answers
559 views

Neutrons reflective materials in nuclear reactors

Nuclear reactors are driven away from criticality with the use of control rods which absorb neutrons. In case of overheating and melting of the core, the control rods may not be inserted any more ...
0
votes
1answer
148 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 ...
2
votes
2answers
501 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
3answers
2k views

Can antimatter be used as fuel for nuclear reactors?

I completely understand the difficulties of making and storing antimatter, so I am not talking about the mechanism or the way of doing it here, I am just talking about the concept. As far as I know, ...
1
vote
1answer
146 views

How to solve the Fukushima incident?

I am trying to find out if it is somehow possible to take all this nuclear material, put it in some type of gamma chamber or blast it with neutrons to change the uranium isotopes into something ...
4
votes
2answers
417 views

Can bad guys really hide “dirty bomb” material via bananas?

This one probably has some cross-over with Skeptics SE, but I thought it fits here a little better. The concept comes from the TV show NCIS:LA second season episode "Empty Quiver" Here, the villains ...
1
vote
0answers
48 views

Nuclear Weapon Effects: Cloud Rise [closed]

I am interested in modeling the rise of a nuclear cloud to stabilization height post detonation. I am interested in any ideas you may have on the approach. I have collected some research on the topic ...
6
votes
4answers
2k views

What is the minimum amount of fissile mass required to acheive criticality?

Wikipedia gives the following definition for critical mass. A critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. No mention is made of a ...
0
votes
1answer
247 views

Fukushima vs Thorium [closed]

This is not a question about traditional nuclear power plants vs the thorium based. But about the Fukushima plant itself and the very negative environmental effects from its meltdown of reactors 1 and ...
-1
votes
1answer
151 views

Why nuclear tests move under ground since 1964?

According to this database: http://www.ga.gov.au/oracle/nuclear-explosion.jsp Since 1962, 99% of USA Nuclear tests was underground. Since 1964, 99% of Soviet Nuclear tests was underground. Is it ...
4
votes
1answer
216 views

Gaseous fission: Has it even been demonstrated experimentally?

I've been reading quite a bit about gas-core reactors, a theoretical reactor design where the fissioning of Uranium(along with Plutonium & possibly Thorium)occurs in gas phase. The result is that ...
1
vote
0answers
165 views

Intensive radiative heat transfer in very hot gas ( >5000K, gas core nuclear reactor related )

The question: At temperatures above ~5000K are not stable any solid or liquid materials or even more complex molecules (such as fullerenes and Polycyclic aromatic hydrocarbons) which emit/absorb ...
1
vote
1answer
122 views

What is the minimum density required for nuclear fission?

This is a followup to a prior question I asked about gaseous nuclear fission. What is the lowest nuclear fuel density required to initiate fission? This is critical for a gas core reactor with a ...
2
votes
1answer
96 views

Could one “build” elements?

I was wondering this: would it be possible to "construct" elements by arranging their constituent particles in high-energy environments? So apart from just fusion, could you sub-atomically manufacture ...
1
vote
1answer
239 views

What would a sufficiently dense sphere of uranium do first: blow up, or form a black hole?

I think it is safe to assume that humans are a long way off from having either the technology to compress a normal-sized sphere of uranium below its Schwarzschild radius, or the technology to create a ...
5
votes
2answers
2k views

Do brick walls effectively protect against ionizing radiation from a nuclear explosion?

Of course it depends on the distance and the amount of radiation, so let's say its about 10,000 Rad. Now, can wall made of brick protect someone behind it from such radiation ?
8
votes
1answer
698 views

Why does it take so long to make a nuclear bomb?

So as I know nuclear bombs are derived from fission reactions: By providing the nucleus with enough power to trigger a chain reaction. If uranium was present why does it take so much to make a nuclear ...
1
vote
2answers
149 views

Theoretic Mass Energy Conversion?

say you had a large quantity of a heavy element such as uranium... AND you put a massive amount of energy into it, so that it began to undergo nuclear fission and transformed to a significantly ...
2
votes
2answers
263 views

Why increase pressure to go from liquid to steam?

Assume the following phase diagram $T-H$ of water At a nuclear engineering course, I was told that in order to increase the performance of a pressurized water reactor, one has to increase the ...
0
votes
0answers
272 views

Constant Pressure lines in evaporation diagram

Assume that there is the following $T-H$ phase diagram with the constant pressure lines. Which is greater preasure? The preasure drops as we move to lower temperatures (i.e. from top to bottom)? ...
2
votes
1answer
113 views

neutron transport approximations for nuclear rocket modelling

I'm pretty ignorant regarding neutron and nuclear transport modelling, but i'm interested in trying to pursue it for a particular pet project. It regards modelling of nuclear reactions like those ...
3
votes
1answer
142 views

Containement system of a nuclear reactor: role of the water moderator

In a modern nuclear reactor for example a PWR there are multiple containment systems which prevent the release of radioactive material into the environment and shield the environment from the ...
12
votes
2answers
5k 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 ...
0
votes
1answer
1k views

Speed of neutrons in a nuclear reactor

How fast (in $\frac{\mathrm{m}}{\mathrm{s}}$) are typical neutrons before and after slowing down in a nuclear reactor (with U-235 and $H_2O$ as moderator)? Do you have any reference for the values?
1
vote
2answers
107 views

Why not assimilate nuclear waste into “igneous” rock?

I was reading a question about why not to drop nuclear waste into volcanoes; the short answer is it would come back out and not be rendered safe. Ignoring the cost and energy requirements, why can't ...
5
votes
1answer
276 views

How is it possible to calculate the energy liberated by a given fission process?

How is it possible to calculate the energy liberated by a given fission process? For example, in the fission of a $^{235}$U induced by capturing a neutron?
3
votes
1answer
446 views

Why is the total interaction cross section larger for incident particles with lower energy?

The cross section of a nuclear interaction is a measurement of the probability of that interaction occuring. These probabilities are typically presented in terms of barns ($10^{-28}$ m$^2$) as a ...
8
votes
2answers
1k views

Military-grade U-235 uses

In the news it is often mentioned that some countries are going to enrich uranium to "military grade" (i.e. 80%+) and that it is possible to use it for a nuclear bomb. 1) Is that correct that there ...
2
votes
1answer
603 views

Why did the Hydrogen in Fukushima explode *outside* the reactor vessel?

As pointed out before, it orginated inside the reactor vessel but exploded outside: how did it get there? Did it pass the shell by diffusion or was it released by the engineers?
2
votes
2answers
386 views

Water-cooled fast neutron reactors

Can anyone explain why fast neutron reactor designs use sodium/lead/salt cooling, instead of water (heavy/light)? Is that because neutron absorption by water would not allow to break even in fuel ...
3
votes
1answer
421 views

Nuclear Salt Water Rockets: viability and follow-up

This is the original paper by R. Zubrin proposing the Nuclear Salt Water Rocket design. Basically the design is that a capillar set of pipes store a uranium salt-water solution, inside a cadmium ...
5
votes
1answer
323 views

What causes the structure visible in first few milliseconds of a nuclear explosion?

Following on from this question, here is a high-speed photograph of a nuclear explosion, taken about 1 ms after detonation: (source) As anna v pointed out, several similar images can be seen in a ...
2
votes
5answers
600 views

Thorium radioactivty vs Uranium radioactivty nuclear power

May i please open this question by asking that if you intended to answer this please could you provide links based on your answer. I have read ( and posted one ) on thorium and a lot of the answers ...
1
vote
0answers
89 views

Properties of spilled spent nuclear fuel pellets

Can someone please explain to me the physics of a pile of spilled nuclear fuel pellets on the floor of a spent fuel pool? Specifically, what can we expect in terms of heat and radioactivity releases, ...
0
votes
1answer
316 views

Direct nuclear reaction in nuclear physics

Time taken to occur a direct nuclear reaction is very low $10^{-22}$sec . I want to know the Importance of direct nuclear reactions.
2
votes
1answer
1k views

Why are we not using thorium for energy? [duplicate]

Possible Duplicate: What practical issues remain for the adoption of Thorium reactors? I have been reading and watching a bit on thorium TH 90 and cannot understand why this is not being ...
1
vote
2answers
404 views

How to detect radiation on the metal (coin)?

I've got metal coin : http://www.worldpeacecoin.org/ Ruble/dollar, a coin of disarmament with certificate. But, I am very spleeny person, I fear of it's radiance level and I don't know if I can trust ...
3
votes
1answer
67 views

The synthesis of $^{254}\text{No}$

How is $^{254}\text{No}$ synthesised? Could you explain the reaction where it is preceded by $^{208}\text{Pb}(^{48}\text{Ca}, 2\text{n})$? References to articles are well enough—I was somehow unable ...
2
votes
1answer
189 views

Is there a good summary of all nuclear fusion approaches?

I am pretty sure, that during last 60 years of well-funded research a lot of ideas on nuclear fusion were already tried and ruled out. Is there some summary describing all of them and why they ...
2
votes
3answers
505 views

Nuclear physics problem, Why do we use high weight atomic elements?

So as far as I know, nuclear fission uses high weight atomic elements to manufacture power. If the risk of runaway reactions are a major reason for not expanding this technology, why don't we use ...
1
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2answers
104 views

Statistical Weighting Factor on thermal neutron importance

The problem is concerning the use of a thermal fluxed squared weighting factor in a thermal reactor. I have seen in sources the thermal flux in a reactor is squared as a statistical weighting factor, ...