Interesting thought. In particular because as I was reading some stuff on Fissile Material Cutoff Treaty, the definition of fissile material is either:
For India the need for military use of fissile material is not only weapons but also to power nuclear powered submarines (and later surface vessels also). The latter requires steady stream of fissile fuel as against material required for a fixed sized weapon inventory.
Only part of the installed capacity of Indian made and locally fueled PHWR can be used for military grade Pu production (mainly limited by fuel loader throughput and availability). If one had the will, yet did not want to compromise plant load factor, my conservative guess is that only ~5 - 7 % of the plant capacity can be used to convert fresh fuel into lightly irradiated fuel rod (and then withdrawn to recover Pu). Thus a 220 MWe PHWR will yield ~ 10 - 15 Kg WgPu /Year. or ~1,900 Kg from all non-safeguarded reactors since inception. It is however unlikely that the reactors have been used like this since inception. More like 20% of what was possible since inception. Viz 380 Kg. Add to that what is obtained from Dhruv ~300 Kg. And assuming all WgPu spent fuel were reprocessed (a question mark in itself), that (680 Kg) defines reasonable estimate of Indian fissile stock.
As far as non-weapon grade Pu, literature shows officials mentioning ~10 tonnes of it, much of it I suspect is un-separated from in the from of spent fuel rods
Now one can see from 680 Kg WgPu, how many pure 20 Kt yield fission bombs ( @ 8Kg per core) can be made? Answer: <85
If one considers half of the fissile material is in form of FBF of 17 Kt yield ( @~2.5 Kg per core) that gives: 42 pure Fission + 136 FBF.
[quote name='Shaurya' date='26 December 2009 - 12:54 AM' timestamp='1261768562' post='103132']
I wanted to post this in response to some speculations on available Indian fissile material.
Gagan: I think you are misreading the statement. At that time, except for 6 reactors, all others, i.e: 14, were not under safeguards. The separation agreement, put another 8 under safeguards. It did not mean that all the 14 non safeguarded reactors were actually being used for military purposes. The general understanding is that their potential for military use has been well understood, however, they were largely being used for civilian purposes. The PHWR's partial use to produce fissile material, would be an inefficient use of available resources and the best way would be, is to have dedicated reactors. The best public guidance for fissile material is a third coming from Cirrus, mentioned in our parliament by Arun Shourie to go by.
Almost ALL others are speculations of India's fissile material, by mostly foreign sources, based on the potential of the non safeguarded reactors, plugged into our civilian grid.
I do not have much evidence, based on Indian sources, beyond what has been publicly cited, but I believe the following, based on readings and understandings.
- Arun Shourie's estimates on Indian FM are correct, but older - pre - 1998 (the statement was made in 2006).
- Post 1998, at least some of the non safe guarded PHWR's are being used to produce fissile material, in partial burn mode
- It was the above, that concerned BM, in initially not endorsing the nuclear deal, however, the INC government assured BM, that they are continuing to produce FM in quantities, consistend with what the NDA regime did, which resulted in him endorsing the deal
My understanding is Dhruva continues to be the main stay for production of Indian FM, supplemented by the TFBR and the Cirrus, to be soon closed down and this gap to be fulfilled by the unsafeguarded PHWR's and as supplemental capability available, if needed.
India's fissile material production, is under the policy guidelines of the MCD. I believe, that K. Subrahamanyam's changes in the view from about 60 weapons needed for deterrence to about 150 weapons, has a direct correlation to the additional fissile material, India has produced. India's main stay of nuclear weapons are pure fission bombs. BF weapons are a high probability and TN weapons have not been deployed. The yields of India's atomic weapons are in the 15-80 KT range, appropriately configured for missiles and gravity war heads. BF weapons are reserved for Agni II AT and Agni III and upcoming Agni V. Shourya will likely have fission bombs and some version of Agni III, when ready for SLBM will have the BF weapons.
Based on the above assumptions, one can come up with some ranges, on what is the likely fissile material that India is likely to have, how much fissile material is used in such weapons but the numbers are only as good as the assumptions. The above assumptions can and should be challenged for I offer no proof and have none. Have fun, calculating these.
[/quote]
K. Subrahamanyam's 60-80 kT is not founded on sound scientific/military methodology, and IMVHO unsubstantiated wet dream.
Upper limit of scaling the 17kT FBF tested in Pok-II is ~50-60 kT, but obviously that article (design) is not validated. Higher yield (I.e. those >50 kT, like 100 kt, 150 kt, or even 200 kt) FBF require high speed diagnostic equipment that India does not have (and Pakistan has that gifted by Chinese). Thus lacking will to test, 50 kt FBF is upper limit of credible weapon yield. One can thus base own assessment above or below K. Subrahamanyam's 80 kT, after all it a guesswork unencumbered by scientific methodology.
- 1. Uranium that is enriched >20%
2. Plutonium that has been separated from spent fuel. (I.e. Spent fuel that is sitting idle from unsafe-guarded reactors awaiting reprocessing can't be counted in Pu inventory of a nation).
3. Looks like there is no mention yet of Fissile Uranium from non-enrichment process (AKA Thorium derived from FBR or AHWR)[/code]
For India the need for military use of fissile material is not only weapons but also to power nuclear powered submarines (and later surface vessels also). The latter requires steady stream of fissile fuel as against material required for a fixed sized weapon inventory.
Only part of the installed capacity of Indian made and locally fueled PHWR can be used for military grade Pu production (mainly limited by fuel loader throughput and availability). If one had the will, yet did not want to compromise plant load factor, my conservative guess is that only ~5 - 7 % of the plant capacity can be used to convert fresh fuel into lightly irradiated fuel rod (and then withdrawn to recover Pu). Thus a 220 MWe PHWR will yield ~ 10 - 15 Kg WgPu /Year. or ~1,900 Kg from all non-safeguarded reactors since inception. It is however unlikely that the reactors have been used like this since inception. More like 20% of what was possible since inception. Viz 380 Kg. Add to that what is obtained from Dhruv ~300 Kg. And assuming all WgPu spent fuel were reprocessed (a question mark in itself), that (680 Kg) defines reasonable estimate of Indian fissile stock.
As far as non-weapon grade Pu, literature shows officials mentioning ~10 tonnes of it, much of it I suspect is un-separated from in the from of spent fuel rods
Now one can see from 680 Kg WgPu, how many pure 20 Kt yield fission bombs ( @ 8Kg per core) can be made? Answer: <85
If one considers half of the fissile material is in form of FBF of 17 Kt yield ( @~2.5 Kg per core) that gives: 42 pure Fission + 136 FBF.
[quote name='Shaurya' date='26 December 2009 - 12:54 AM' timestamp='1261768562' post='103132']
I wanted to post this in response to some speculations on available Indian fissile material.
Gagan: I think you are misreading the statement. At that time, except for 6 reactors, all others, i.e: 14, were not under safeguards. The separation agreement, put another 8 under safeguards. It did not mean that all the 14 non safeguarded reactors were actually being used for military purposes. The general understanding is that their potential for military use has been well understood, however, they were largely being used for civilian purposes. The PHWR's partial use to produce fissile material, would be an inefficient use of available resources and the best way would be, is to have dedicated reactors. The best public guidance for fissile material is a third coming from Cirrus, mentioned in our parliament by Arun Shourie to go by.
Almost ALL others are speculations of India's fissile material, by mostly foreign sources, based on the potential of the non safeguarded reactors, plugged into our civilian grid.
I do not have much evidence, based on Indian sources, beyond what has been publicly cited, but I believe the following, based on readings and understandings.
- Arun Shourie's estimates on Indian FM are correct, but older - pre - 1998 (the statement was made in 2006).
- Post 1998, at least some of the non safe guarded PHWR's are being used to produce fissile material, in partial burn mode
- It was the above, that concerned BM, in initially not endorsing the nuclear deal, however, the INC government assured BM, that they are continuing to produce FM in quantities, consistend with what the NDA regime did, which resulted in him endorsing the deal
My understanding is Dhruva continues to be the main stay for production of Indian FM, supplemented by the TFBR and the Cirrus, to be soon closed down and this gap to be fulfilled by the unsafeguarded PHWR's and as supplemental capability available, if needed.
India's fissile material production, is under the policy guidelines of the MCD. I believe, that K. Subrahamanyam's changes in the view from about 60 weapons needed for deterrence to about 150 weapons, has a direct correlation to the additional fissile material, India has produced. India's main stay of nuclear weapons are pure fission bombs. BF weapons are a high probability and TN weapons have not been deployed. The yields of India's atomic weapons are in the 15-80 KT range, appropriately configured for missiles and gravity war heads. BF weapons are reserved for Agni II AT and Agni III and upcoming Agni V. Shourya will likely have fission bombs and some version of Agni III, when ready for SLBM will have the BF weapons.
Based on the above assumptions, one can come up with some ranges, on what is the likely fissile material that India is likely to have, how much fissile material is used in such weapons but the numbers are only as good as the assumptions. The above assumptions can and should be challenged for I offer no proof and have none. Have fun, calculating these.
[/quote]
K. Subrahamanyam's 60-80 kT is not founded on sound scientific/military methodology, and IMVHO unsubstantiated wet dream.
Upper limit of scaling the 17kT FBF tested in Pok-II is ~50-60 kT, but obviously that article (design) is not validated. Higher yield (I.e. those >50 kT, like 100 kt, 150 kt, or even 200 kt) FBF require high speed diagnostic equipment that India does not have (and Pakistan has that gifted by Chinese). Thus lacking will to test, 50 kt FBF is upper limit of credible weapon yield. One can thus base own assessment above or below K. Subrahamanyam's 80 kT, after all it a guesswork unencumbered by scientific methodology.