05-22-2012, 08:49 PM
[quote name='Arun_S' date='22 May 2012 - 10:17 AM' timestamp='1337661560' post='114938']
Just calculate the number of joules in 0.7g HEU and you will see the fallacy. And of course I dont believe anyone has a thermal engine that has >100% thermal to mechnical efficiency to get that much shaft horse power in that small HEU.
Easy to test MV Ramana's "Brahma Gyaan".
[/quote]
http://fissilematerials.org/library/hip86.pdf
Actually this isn't his gyaan but those of Albert.The figures also account for mechanical conversion. The calculcations in the report are based on shp as opposed to thermal output and therefore look only at propulsion figures. So a maximal estimate of 640 kg of 40% HEU also does not detract from this. Even 1 ton of HEU or Arihant will not distract from the figures presented on the enrichment exceeding the requirements of 10 submarines. So I have just made use of the figures and doubled it twice. He thinks it's 90kg based on he report. I think it's 330kg of 40%HEU with an upper end uncertainty of 100% accounted for of up to 660kg of 40% HEU. I will recheck these figures of the 1989 paper when I get more time.(I am not taking Raman at his face value as I have account for his conversion error from 97%HEU to 40%HEU and double that.) I doubt the figures quoted in his paper are too far off. The context isn't India specific. I anything is US vs USSR. So the figures are to be viewed in that context. There is also the comparison to French prototype reactors which ran on shore a 0.6 to 0.7 g of HEU per shaft horse power per year. The reactor ran at near full burnup or six months to achieve the burnup. Operational rectors in nuclear submarines rarely produce peak power at all times. The naval vessels are also no on patrol all the time and even when on patrol they don't move at the highest rated speed. These peek power requirements are when the vessels are simulating a chase or in a chase or are trying to loose a tail. These figures account for the time off from patrols and also the reactors being run at lower burn ups when they are on patrol and stationary under the sea. So I don't see any reason to discredit that report as well.
That this is not an unreasonable estimate can be seen if we take into account the following information:
o One gram of U-235, fissioned completely, would yield a o t 0.96 Megawatt-days or about 3.5 horsepower-years of energy.
9-Y
o The actual fraction of the U-235 in the fuel that is fissioned is very roughly 35 percent.
o Of the fission heat released, perhaps 20 percent would be converted to mechanical shaft power on average (the peak conversion efficiency of a
commercial pressurized- water nuclear power plant is 0.33).
Given an average core life of 5 years prior to 1970, and 0.6 grams of U-235 per rated shaft-horsepower (shp) year, each new reactor core would
contain about 3 grams of U-235 per rated shp. (This would give 45 kg. for a 15,000 shp reactor in good agreement with the specifications of the French prototype.)
By 1965, all reactors started in 1955 or earlier (0.015 million shp,according to Table 2-3) would have been fueled three times, all reactors
started from 1956 through 1960 (0.485 million shp) would have been fueled twice, and all reactors gtarted from 1961 through 1965 (0.740 million shp)
would have been fueled only once. If we, in addition, assume the equivalent of 1.25 extra cores available for every reactor in operation in
1965 (1.24 million shp), the total amount of U-235 that would have been required to be provided for the naval reactors would be:
3*(0.015*3 + 0.485*2 + 0.740*1 + 1.24*1.25) - 10 tonnes. This would be the equivalent, in terms of separative work requirements, of about 11 tonnes of weapon-grade uranium (WGU). (The equivalence ratio is insensitive to the tails assay.) In Table 2-2, we show a 50 percent
uncertainty range on this estimate.
Just calculate the number of joules in 0.7g HEU and you will see the fallacy. And of course I dont believe anyone has a thermal engine that has >100% thermal to mechnical efficiency to get that much shaft horse power in that small HEU.
Easy to test MV Ramana's "Brahma Gyaan".
[/quote]
http://fissilematerials.org/library/hip86.pdf
Actually this isn't his gyaan but those of Albert.The figures also account for mechanical conversion. The calculcations in the report are based on shp as opposed to thermal output and therefore look only at propulsion figures. So a maximal estimate of 640 kg of 40% HEU also does not detract from this. Even 1 ton of HEU or Arihant will not distract from the figures presented on the enrichment exceeding the requirements of 10 submarines. So I have just made use of the figures and doubled it twice. He thinks it's 90kg based on he report. I think it's 330kg of 40%HEU with an upper end uncertainty of 100% accounted for of up to 660kg of 40% HEU. I will recheck these figures of the 1989 paper when I get more time.(I am not taking Raman at his face value as I have account for his conversion error from 97%HEU to 40%HEU and double that.) I doubt the figures quoted in his paper are too far off. The context isn't India specific. I anything is US vs USSR. So the figures are to be viewed in that context. There is also the comparison to French prototype reactors which ran on shore a 0.6 to 0.7 g of HEU per shaft horse power per year. The reactor ran at near full burnup or six months to achieve the burnup. Operational rectors in nuclear submarines rarely produce peak power at all times. The naval vessels are also no on patrol all the time and even when on patrol they don't move at the highest rated speed. These peek power requirements are when the vessels are simulating a chase or in a chase or are trying to loose a tail. These figures account for the time off from patrols and also the reactors being run at lower burn ups when they are on patrol and stationary under the sea. So I don't see any reason to discredit that report as well.
That this is not an unreasonable estimate can be seen if we take into account the following information:
o One gram of U-235, fissioned completely, would yield a o t 0.96 Megawatt-days or about 3.5 horsepower-years of energy.
9-Y
o The actual fraction of the U-235 in the fuel that is fissioned is very roughly 35 percent.
o Of the fission heat released, perhaps 20 percent would be converted to mechanical shaft power on average (the peak conversion efficiency of a
commercial pressurized- water nuclear power plant is 0.33).
Given an average core life of 5 years prior to 1970, and 0.6 grams of U-235 per rated shaft-horsepower (shp) year, each new reactor core would
contain about 3 grams of U-235 per rated shp. (This would give 45 kg. for a 15,000 shp reactor in good agreement with the specifications of the French prototype.)
By 1965, all reactors started in 1955 or earlier (0.015 million shp,according to Table 2-3) would have been fueled three times, all reactors
started from 1956 through 1960 (0.485 million shp) would have been fueled twice, and all reactors gtarted from 1961 through 1965 (0.740 million shp)
would have been fueled only once. If we, in addition, assume the equivalent of 1.25 extra cores available for every reactor in operation in
1965 (1.24 million shp), the total amount of U-235 that would have been required to be provided for the naval reactors would be:
3*(0.015*3 + 0.485*2 + 0.740*1 + 1.24*1.25) - 10 tonnes. This would be the equivalent, in terms of separative work requirements, of about 11 tonnes of weapon-grade uranium (WGU). (The equivalence ratio is insensitive to the tails assay.) In Table 2-2, we show a 50 percent
uncertainty range on this estimate.