Calculating Fissile Plutonium output to estimate nuclear capability of a country

[diabolic]

Hi all,

I am just a mechanical engineer with no good background of nuclear physics. As I am doing some research on how much each country can posses nuclear bomb. The question is if I know the reactor location (approximate) , type of reactor and its Rated power (MWe) with assumed plant capacity factor of (75% for power mode & 80% for weapon grade mode) how can I calculate Spent (Uranium) Fuel / Yr (Kg) and Fissile Plutonium
output / Yr (Kg)

thanks,
Diabolic

 

[Astronuc]

The quantity of Pu produced depends on several factors: thermal power (roughly 3 times the GWe), mass of fuel in the reactor, irradiation time are principal, enrichment (fraction of U-235 and/or other fissile isotope), and the refueling schedule and batch size (number of fresh assemblies or fraction of core introduced during refueling).

The amount of Pu produced in nuclear fuel depends upon the conversion ratio (U-238 to Pu-239), which is a function of the burnup (GWd/tU, or MWd/kgU), and the mass of fuel in which the Pu is being produced.

 

[Dozent100]

Hi all,

I am just a mechanical engineer with no good background of nuclear physics. As I am doing some research on how much each country can posses nuclear bomb. The question is if I know the reactor location (approximate) , type of reactor and its Rated power (MWe) with assumed plant capacity factor of (75% for power mode & 80% for weapon grade mode) how can I calculate Spent (Uranium) Fuel / Yr (Kg) and Fissile Plutonium
output / Yr (Kg)

thanks,
Diabolic

In a word, No! There are many, many other factors that determine product production. The Enrichment of the fuel, the flux density, The arrangement of the fuel and target material in the core. The free mean path of the neutrons. Fissile production requires very high flux density. To thermalize neutrons to produce weapons grade product, is not easy. In general, it is difficult to produce usable weapons grade material with a power reactor.
Any more than that, I would refer you texts on reactor design.

 

[diabolic]

Thanks for ur inputs but I need to know how did the person in this paper calculate the fuel spent and plutonium yield.
http://www.indiaresearch.org/Indo-USStrategicDeal.pdf"

 

[Dozent100]

Actual Numbers

Thanks for ur inputs but I need to know how did the person in this paper calculate the fuel spent and plutonium yield.
http://www.indiaresearch.org/Indo-USStrategicDeal.pdf"

They could be actual production numbers? Note the wide range of the estimates!

 

[Astronuc]

I'm not sure how Sharma determined the yields, but perhaps it was based on knowledge of the discharge burnup and conversion ratio, and some knowledge of the fuel design. As Dozent100 noted, there is a range, and there is likely a wide band of uncertainty.

 

[diabolic]

Sir,
When I try to emulate the same calculation I am not able to get the same numbers. For example Kaiga – 1 (PHWR) having power of 220 Mwe

Spent Fuel / Yr (Kg) = 220*3 (MWt)*1000 (for Kg) * 365 (days) * 0.75 (Plant capacity factor for power mode) /1.348 (U235 required / MWe-Year )

= 34638 kg/yr but the paper gives a value of 35,427 kg/yr

where am I going wrong? More over I could not get the logic he has used for calculating Fissile Plutonium output.

All I know is FAS (http://www.fas.org/nuke/intro/nuke/plutonium.htm") States, 1 megawatt-day (thermal energy release, not electricity output) of operation produces 1 gram of plutonium in any reactor using 20-percent or lower enriched uranium;

Wonder how he has used this data.

Dozent100, I do agree that it is just plutonium output and only a fraction of it will be converted into nuclear weapons. Still knowing these number will give approximate potential of that country. Plz tell ur opinion.

 

[Dozent100]

Pu Production

There is a large difference between producing Plutonium and producing weapons grade plutonium. I won't go into those differences in an open forum because many are still classified. Of course, "Weapons grade" is only a desirable blend of Pu Isotopes, if you don't mind killing off your workers that have to handle the Pu to make a weapon.

I would point out that most of what you are trying to determine is in open literature. The real question is why do you need this data and what do you intend to do with it?

The answer has not changed: The Plutonium production in any particular reactor load, depends on may variables, including the isotopic make up of the fuel, and the target material; the core configuration; the moderator; The neutron darkness of the reactor internals, just to nane a few. You have to have a detailed knowledge of the physical design, metalurgical make-up of the core. Consider also the purity of the moderator, whether light water, heavy water, or something else.

I'll say it again, based on the information you have provided, The answer is not available. Trust me I used to do this for a living, including 5 years as an IAEA Safeguards Inspector.

 

[diabolic]

if you don't mind killing off your workers that have to handle the Pu to make a weapon. .

thanks for ur candid reply. Surely the work will be killed when I am going nowhere

The real question is why do you need this data and what do you intend to do with it? .

the answer is simple. The data I will be colleting is for self. When I stumbled accidentally pu on this link http://stinet.dtic.mil/cgi-bin/GetTRDoc?AD=ADA460305&Location=U2&doc=GetTRDoc.pdf" and when INDIA is signing a deal with US whated to study the effect of the deal with “deterrence postures” what to assess how much India is venerable and capability of china and Pakistan.

The answer has not changed: The Plutonium production in any particular reactor load, depends on may variables, including the isotopic make up of the fuel, and the target material; the core configuration; the moderator; The neutron darkness of the reactor internals, just to nane a few. You have to have a detailed knowledge of the physical design, metalurgical make-up of the core. Consider also the purity of the moderator, whether light water, heavy water, or something else. .

I do agree with all these things. For any outsider will also not know the answer for these. But still you could see people doing calculations for example so even I wanted to those calculations to get a feel

I'll say it again, based on the information you have provided, The answer is not available. Trust me I used to do this for a living, including 5 years as an IAEA Safeguards Inspector.

:-((

 

[Dozent100]

The final word

thanks for ur candid reply. Surely the work will be killed when I am going nowhere
? No Bic!



the answer is simple. The data I will be collecting is for self. When I stumbled accidentally pu on this link URL="http://stinet.dtic.mil/cgi-bin/GetTRDoc?AD=ADA460305&Location=U2&doc=GetTRDoc.pdf"]http://stinet.dtic.mil/cgi-bin/GetTRDoc?AD=ADA460305&Location=U2&doc=GetTRDoc.pdf[/URL] and when INDIA is signing a deal with US. whated (WANTED?) to study the effect of the deal with “deterrence postures” what to assess how much India is venerable and capability of china and Pakistan.

Very Dangerous ground for a civilian to play on. India, Pakistan, and China would all consider these "State Secrets" of the highest nature. 20 years ago I would have been able to access this info, but not now, and even if I could, I couldn't reveal such information, least of all in a public form.

You have hit the crux of enforcing The Nuclear Non-Proliferation Treaty. The International Community can only rely upon voluntary compliance. That is why India, Iran, and N. Koera have been so vehemently condemmed.
They violated the NPT by developing weapons while signatories. They have thus proved themselves un-trustworthy in dealing with the International Community.

In my day, the Director General of the IAEA reported non-compliance to the Security Council. The IAEA's responsibility ended there. Inspectors were not allowed to search for non-compliant facilities. Nor could they "investigate." We were given quantities shipped into a facility and quantities shipped out. The facility itself was a black box. So in fact only transfers were audited. Hold-up in fabrication, Burn, or reprocessing was a unknown quantity. In fact, attempts to determine isotopic quantities, were met with general protests. In the case of Iraq, who was reported for 5 years, and Pakistan for 7 years as being in non-compliant, no action was taken by the UN Security Council because of Russian veto's. ( Russian and French Contractors were the primary builders of the Iraqi Osirak Reactor which was found to have a Beam Chamber to a hidden room for the irradiation of U238.

Since that time, a new protocol has been written and new signatures are required, by the member nations. Approximately half of the member nations have signed. The new protocols allow the IAEA to investigate non-compliance with the NPT, require the Security Council to act upon reports, and VETO is NOT ALLOWED! Sanctions of the most ecomonacally. devastating type. Freezing all a nation's external assets, freezing all trade are almost automatic. Which, of course, considerably raises the ante For non-compliance. The list of the nations who have refused to sign or dropped out of the NPT rather than sign is very interesting.

I refer you to WWW.IAEA.org
Good luck