Questions tagged [nuclear-engineering]
The study of radiation and radioactive materials and it's creation, safety, and applications.
297
questions
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1answer
24 views
SFR Breeders on Small Mars Moon feasibility [on hold]
Need help with a topic for a sci-fi book. Basic premise is 200yr in future, mining facility on small Mars moon of Phobos. Power source we would like is an SFR breeder as we think this would be cost ...
0
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2answers
54 views
What if nuclear chain reactions were not possible
Nuclear fission chain reactions occur when a nucleus breaks apart, producing at least one neutron, which then causes nearby nuclei to fission, a multiplying process when the average number of produced ...
0
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0answers
19 views
Modeling the cooling rate of a nuclear fireball in space
I am interested in modelling the cooling and luminosity curves for a nuclear detonation in space (after the release of the prompt radiation). How do I get the timing of the second hump right?
I tried ...
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1answer
54 views
Assessing the Viability of Nuclear Initiator Device for Energy [closed]
Disclaimer: This question is purely theoretical and is merely intended to serve as a means of creating a model for a nuclear detonator-based power source. No association to weapons is implied.
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1answer
38 views
Which operations of a nuclear reactor are controlled by humans? [closed]
I understand in a general term how a reactor works, but I was wondering whether they are highly automated or not. Such as do humans control thing such as fuel and coolant flow rates?
3
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1answer
123 views
Was Chernobyl Explosion a Small Nuclear Detonation?
The Chernobyl reactor was designed to produce a maximum of 3.2 megawatts of power. It is now estimated to have produced 3.2 gigawatts of power in the final second of its life.
The original ...
2
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1answer
120 views
How can I find a theoretical maximum amount of radioactively polluted water which could be created by a single nuclear reactor?
This question has a lot of tolerance.
The current context is that I'm writing a story which involves a group of terrorists who are using the threat of radioactive water pollution to deter ...
0
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0answers
52 views
Inexpensive nuclear reaction simulation tools
I am interested in seeing if there are any simulation software programs for less than $50 that may be used to simulate how neutrons (energies between thermal and 15 MeV) interact with certain nuclei ...
0
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1answer
41 views
Q Value for 64-Zn(n,2n)63-Zn [closed]
I've been looking for the Q-value for this reaction for quite sometime now but haven't had any luck with it.
What is the Q-value for the equation and how much energy would each of the neutrons ...
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0answers
33 views
Significance of “MT=” in nuclear science cross sections
I recently came across a measurement on jaea.go.jp/ (a site that publishes nuclear cross section tables). The cross section table had a unit known as "MT" for boron and other elements. I was curious ...
0
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1answer
51 views
Units of radiation dose
I have been reading a few papers on radiation therapy and have come to something I do not understand. In some of the papers they express the dose rate in the following units
$$\frac{MeV}{g\space Bq\...
0
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1answer
42 views
Why is the secondary inlet temperature in a Pressurized Water Reactor (PWR) so high?
According to this link (along with many other PWR papers), the inlet temperature of the secondary into the steam generator is around 450-500K, with a pressure of 5-8MPA. How does the temperature of ...
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1answer
40 views
Producing Uranium 235, not just separating it from 238
Uranium enrichment seems more like a complex filtering process where we separate the precious U-235 from from U-238. Is there a way to actually turn U-238 into U-235?
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2answers
59 views
Nuclear-powered Ramjet + criticality
I came across this Wikipedia entry about Project Pluto; a nuclear-powered ramjet that the U.S. was developing back in the day.
https://en.wikipedia.org/wiki/Project_Pluto
This missile would have ...
0
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2answers
66 views
Could you use the detonation of a Hydrogen bomb or atomic bomb to start a nuclear fusion reactor [closed]
Would this lead to a reactor that produced more energy than you put in?
5
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1answer
190 views
*Why* were the Chernobyl control rods tipped with graphite?
I understand the graphite tips of the boron control rods displaced water (a moderator) which lead to an increased reaction rate, rise in temperature and steam pressure etc.
Question: why were the ...
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1answer
57 views
Increase the Inverse Beta Decay Cross Section for Ti-48
Is there a theoretical way to increase the cross section of inverse beta decay for Ti-48? This would be any method for increasing the likelyhood that Ti-48 absorbs an anti neutrino and creates Ca-48 ...
0
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0answers
18 views
MCNP Summary Table
MCNP6 Version 1 produces a summary table of the results. Much of this table looks very useful, but I am not sure I understand the details. Here is an example.
I'd be grateful for any hints about ...
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0answers
18 views
Calculating leak rates in a pressurized system
I am struggling to come up with an equation which would calculate pressure changes in a system with a pressurizer. The system is 12,710 ft^3, with a pressurizer volume of 1800 ft^3. The pressurizer ...
0
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0answers
50 views
Threshold energy of Ti-48 inverse beta decay
Goal: Use anti neutrinos to convert Ti-48 to Ca-48 using inverse beta decay (IBD). The resulting Ca-48 should have the same half-life as natural Ca-48.
Question: What is the threshold energy for the ...
0
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2answers
85 views
High Flux Antineutrino Sources
I was curious if there were any anti neutrino sources with a similar flux to a nuclear reactor. My current purpose does not allow for a nuclear reactor, however, any flux source with a similar flux ...
8
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1answer
133 views
Origin of Ba-133 contamination
On a stainless steel part that was removed from a spent fuel pool of a pressurized water reactor, we found (among the usual contamination with activated corrosion products, fission products, and ...
0
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1answer
21 views
Linear Reactivity Model
The Linear Reactivity Model seems to be a model for the consumption of the nuclear fuel management.It is a powerful tool to estimate the main performances in function It is a very simple way to choose ...
1
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1answer
39 views
References about “neutronic” algorithms
I am looking forward to apply for an internship in 5 months and I looked up the Jobs offers from last year, and some of them asked for a candidate with knowledge of "algorithms applied to neutronics". ...
0
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1answer
47 views
How to transform activity ratio to isotope ratio? [closed]
I am given a table that describes an ancient spillage of spent nuclear fuel:
...
0
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2answers
58 views
How can a light-water reactor breed plutonium-239?
The "Light-water reactor" Wikipedia page states that "the uranium 238 atoms also contribute to the fission process by converting to plutonium 239". But from what I've read you need fast neutrons to ...
0
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1answer
43 views
Nuclear Reaction Conservation of Nucleons
I'm having a hard time trying to understand a nuclear reaction:
$$_{2}^{1}\textrm{He} + {}_{3}^{6}\textrm{Li} \rightarrow
{}_{\phantom0 5}^{10}\textrm{B} \rightarrow {}_{4}^{9}\textrm{Be} + {}_{1}^{...
0
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1answer
65 views
Has proton-proton fusion ever been seriously considered for an artificial fusion reactor?
All contemporary efforts to perform nuclear fusion as a source of power have focused on reactions between isotopes (often deuterium, tritium, or He3) and/or light elements (often boron or lithium ...
8
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4answers
2k views
Does a proton have a binding energy?
When calculating the $Q$-value, $Q = \Delta M \cdot c^2$, of this reaction:
$$ ^6Li \ (\alpha, p)\ ^9Be \quad \iff \quad \alpha + \ ^6Li \ \longrightarrow \ ^9Be + p $$
The $Q$-value can also be ...
0
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1answer
96 views
Is this a radioactive meteorite? [closed]
Can a neutron beam emission from a strong naturally-occurring radioisotope deflect a small sewing needle hung by a thread an inch from the source? I have someone reporting to me of such a thing ...
1
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0answers
238 views
How exactly did lowering of the graphite parts of the control rods on Chernobyl's RBMK reactor result in reactivity surge?
There are many sources giving different data on the initial position and the dimensions of the rods, but most suggest that the absorber was located just outside the core when AZ-5 was pressed, and the ...
0
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1answer
89 views
Why does fusion above nickel 56 require energy?
I've always struggled with the concept of fission and fusion. I mean I can show a mass deficit with math easily enough but I have always struggled understanding the fundamental concept of why things ...
3
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2answers
115 views
Why don't we coat the pressure vessels of nuclear reactors in boron to reduce neutron embrittlement?
Neutron embrittlement is a big problem in reactor design, as high energy neutrons cause lattice defects in materials like steel by slamming into iron nuclei. This limits the lifetime of the reactor, ...
1
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2answers
256 views
Comparing radiation levels - Chernobyl vs Moon
How radiation from Chernobyl disaster compares to cosmic radiation on the surface of the Moon (effect on human cells and electronic devices)?
Why Chernobyl liquidators suffered heavily from ...
17
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1answer
7k views
Why is the graphite moderator in a nuclear reactor radioactive?
Some nuclear reactors (like the RBMK in Chernobyl) use graphite as a neutron moderator. As far as I understand, this graphite material, either in rods or as blocks with embedded channels, surrounds ...
6
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2answers
291 views
Why does steam in Chernobyl reactors speed up nuclear reaction?
After watching the TV series Chernobyl I am struggling to understand why steam in a reactor core would increase the rate of the nuclear reaction. My first guess would be that liquid water would ...
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1answer
51 views
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1answer
63 views
What if a fusion reactor had moving parts?
I have never dug into fusion physics, but from what I gather one of the main problems is confining the fusion in a small region of space for long enough to get enough helium fused to counterbalance ...
4
votes
3answers
390 views
Whats the next step after commercial fusion reactors? [closed]
I'm trying to write some science fiction where they've had nuclear fusion working for quite sometime, interplanetary travel is no problem, and they're debating making the next step to a radical new, ...
2
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0answers
63 views
Why is the D+P fusion reaction not considered for large-scale power production?
I know that D+D (fusion of deuterium + deuterium nuclei) as well as D+T (fusion of deuterium and tritium nuclei) are the reactions most commonly considered for large-scale power production. Why not D+...
2
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2answers
111 views
If a country wants to build nuclear weapons, why would they enrich uranium instead of turning uranium to plutonium? [closed]
Firstly, I have to say that I'm bad at physics. So, please correct me if I say something wrong.
I have read that natural uranium contains 99.28% of U-238 and only 0.72% of U-235 which is the ...
0
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1answer
76 views
Help in identifying an instrument used in nuclear physics
In American-British drama miniseries Chernobyl, on the second episode, a scientist takes some dust from the outer surface of a window and places it in an instrument that tells her what radioactive ...
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0answers
227 views
Could the pressure from the steam explosion in Chernobyl (if it occured) have made the corium critical?
As other questions (eg How large would the steam explosion at Chernobyl have been?) regarding that episode 2 of the Chernobyl series, the megaton estimate of the steam explosion looked very improbable ...
0
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0answers
240 views
Risk of megaton steam explosion from Chernobyl? [duplicate]
In the new Chernobyl TV series (https://en.wikipedia.org/wiki/Chernobyl_(miniseries)), in episode 2, there's a reference to the risk of a steam explosion from the molten reactor core entering a water ...
18
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8answers
13k views
How large would the steam explosion at Chernobyl have been?
So the second episode of the HBO series began to cover the risk of a steam explosion that led to them sending three divers into the water below the reactor to drain the tanks.
This occurred after the ...
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0answers
40 views
Could a long wire of uranium control nuclear reactions?
If you fashioned a very thin wire of uranium, perhaps coated in Lead, then started a nuclear chain reaction at one end, could you create a sustainable safe nuclear power?
Since the nuclear reaction ...
0
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1answer
47 views
Nuclear Propulsion
I am watching a video on nuclear rocket engines, specifically the Nerva engine. It has a propulsion efficiency of 750-800 Isp versus chemical rockets which are only 350-400 Isp. The follow on NRX ...
3
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1answer
134 views
Is making nuclear bomb using natural uranium possible?
I know that the critical size of natural uranium metal with graphite moderator is about 27 tons "oak ridge graphite reactor". for comparison highly enriched uranium have only 17 kg critical size with ...
0
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2answers
69 views
Fission inside nuclear reactor
I have studied about nuclear reactors and also know their functionality.But some how i couldn't get answers for some my questions.
1) During fission reaction enormous amount of heat is produced and ...
0
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0answers
105 views
Why did the Lockheed Martin compact fusion reactor failed? [duplicate]
What made the compact fusion reactor to not be compact. What assumptions did lokheed made in its simulation that showed that it could work. Can we do anything that could make it work or it is ...
