Screaming Skull
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Nuclear Powerplant Design:
The most important part of the submarine is the nuclear powerplant. Very little information is available concerning the powerplant. Certainly the time spent on the leased Soviet nuclear submarine provided valuable design information. However the radiation problems encountered caused much concern.
Uranium in three different levels of enrichment is suitable for use in naval nuclear reactors. The US uses highly enriched uranium (>90%) in its reactors. The use of this level of enrichment ensures long reactor lifetimes.
Soviet submarines are known to have used both medium and low level enriched uranium. Recent reactor designs incorporate highly enriched uranium in the core. The use of low level enriched uranium by China and France has also been described.
At the present time, India does not appear to have the capability of separating large amounts (hundreds of kilograms per year) of highly enriched uranium. Both their centrifuge plants and their experimental laser isotope separation facility appear more suited to low level enrichment. An additional indication that these facilities are not up to full capacity is the sale last year of low enriched uranium by China. This uranium is destined for India's commercial power reactors and would be subject to international safeguards.
Recent evidence seems to indicate that India has the capability to produce the required highly enriched (>90%)uranium needed for the submarine reactor core.
It would also be more economical for India to use low level enriched uranium in its experimental naval reactor. (32)According to P.K. Chari, the former director of the Institute of Defense Studies and Analyses (IDSA) and currently Professor of national Security Studies at the Centre for Policy Research, New Delhi enriched (20%) uranium would find use in a reactor to power submarines. However the use of low level enriched uranium also poses problems. Fuel changes to replace fissioned uranium are needed more often. This poses particular problems for India as there are no suitable facilities capable of handling radioactive materials.
Two different type of reactors would have also been considered. The water-cooled water-moderated reactor (PWR) was designed by BARC and is believed based on Soviet design information obtained form the leased submarine. Some information is known about Soviet reactor design. Naval reactor cores have been described as having 248-252 fuel assemblies depending upon type of reactor. There may be up to a few tens of fuel rods per assembly.
A second liquid metal cooled reactor was probably looked at by Kalpakkam. The pressurized water-cooled reactor is the far better choice and appears to be the reactor chosen for the nuclear powered submarine.
It is now known that China used information obtained about naval ship reactors to help design their first submarine reactor. Information was openly obtained about the West German reactor used on the Otto Hahn and the Soviet reactor used on the Lenin. This information would have surely been available to India.
Indian sources also mention information about a Japanese naval nuclear reactor (Mutsu) and its suitability for use in a submarine.
Most PWR fuel is uranium-aluminum dispersed fuel (cermet) in steel or zirconium cladding. (36)Indian scientists from BARC and the Indian Institute of Technology have published a number of recent papers describing the uranium-aluminum and uranium-zirconium phases.
Enrichment of the PWR core has varied from 21% to as high as 45% for later version cores. A typical first generation core contained approximately 50 kg of U-235 per reactor.
India is very experienced in the design and use of cermet fuel for small reactors. As cited earlier the uranium-aluminum phase diagram has been detailed and the effect of additives such as silicon has been examined. Both Aspara and Zerlina are known to have used medium enriched uranium.
Aluminum clad uranium fuel elements are also in use in both the Cirus and Dhruva reactors. The uranium used in both of these reactors is of the unenriched type and is produced at the Uranium Metal Plant located at Trombay. Fabrication of the fuel elements is done at the Fuel Fabrication Division of BARC. Experience gained in the fabrication of these fuel elements would be invaluable in the design of submarine fuel elements.
If a cermet or aluminum clad uranium is not used then enriched uranium dioxide clad in zircaloy fuel elements may be considered. The Nuclear Fuel Complex at Hyderabad produces zircaloy clad uranium dioxide for both pressurized heavy water reactors and boiling water reactors. Both natural and low level enriched uranium dioxide are used at this facility.
The reactor and its containment vessel are reported to weigh some 600 tonnes. The pressurized water reactor (PWR) will use enriched uranium in the form of plate-type fuel elements.
The steam turbine design and test facilities for use with the nuclear reactor have been set up at Vizag.
Consideration had been given to using a mixed plutonium-uranium oxide fuel in the form of small diameter pins, but that was dropped in favor of enriched uranium in the form of plate-type fuel elements.
Core design, neutronics, power distribution coefficients and criticality calculations all are performed by BARC. Calculations are done in-house using codes developed by both BARC and Kalpakkam scientists. A locally designed supercomputer (PARAM) using parallel processing computers may aid in these efforts, although American and Japanese supercomputers are available for use. (42)Techniques have also been developed at the Advanced Numerical Research and Analysis Group to improve processing speeds of computers by exploiting parallel processing.
According to Kotta Subba Rao Indian nuclear scientists under the guidance of Drs. Ramanna, Srinivasan, and Iyengar have been trying since 1971 to build a nuclear submarine reactor. Three different reactor designs were evaluated. The first was rejected in late 1976, the second in 1979 and the third in 1981.
Problems have existed in the design of certain safety features. An important item in submarine nuclear reactors is the design of the control rod insertion and withdrawal mechanism. This may have been responsible for the radiation leaks aboard the leased Soviet submarine which lead to the reported death of at least one Indian scientist. It is known that India tried to buy a rod worth minimizer ((RWM) used by reactor operators to guide and monitor the proper sequences for the withdrawal and insertion of control rods. The sale was denied.
The control rod technology for use with the rod worth minimizer has been well developed by India. They are able to adequately separate hafnium from zirconium and have also evaluated the worth of hafnium as compared to cadmium for use in control rods. The use of liquid poison systems has also been evaluated.
It has also been reported that the Russian submarine-design bureau Rubin is cooperating in developing the nuclear submarine's 190 MW PWR. Russian engineers have been working with DRDO on the design since 1991.
Even thought India possesses much experience in reactor design and fuel fabrication, construction of the reactor does not appear to gone much past the land based prototype stage. The major holdups appear to be the lack of a suitable harbour facility for handling radioactive materials, lack of an adequate supply of highly enriched uranium, reactor integration and design problems and financial considerations.
The PWR failed tests at Kalpakkam in November and December 1995. The failures were believed to be caused by "several integration and fabrication problems" that have yet to be solved.
In June of 1996 it was reported that the program suffered further setbacks following additional failed tests of the reactor. Problems in fabricating the containment vessel have also occurred.
In July of 1996 it was reported by Delhi All India Radio that "India has successfully developed a nuclear-powered submarine for the navy. The submarine named the Advanced Technology Vehicle was tested successfully somewhere in the East coast recently."
Underwater tests on the reactor were scheduled for late 1996 but are on hold till problems encountered during the earlier tests are resolved.
The most important part of the submarine is the nuclear powerplant. Very little information is available concerning the powerplant. Certainly the time spent on the leased Soviet nuclear submarine provided valuable design information. However the radiation problems encountered caused much concern.
Uranium in three different levels of enrichment is suitable for use in naval nuclear reactors. The US uses highly enriched uranium (>90%) in its reactors. The use of this level of enrichment ensures long reactor lifetimes.
Soviet submarines are known to have used both medium and low level enriched uranium. Recent reactor designs incorporate highly enriched uranium in the core. The use of low level enriched uranium by China and France has also been described.
At the present time, India does not appear to have the capability of separating large amounts (hundreds of kilograms per year) of highly enriched uranium. Both their centrifuge plants and their experimental laser isotope separation facility appear more suited to low level enrichment. An additional indication that these facilities are not up to full capacity is the sale last year of low enriched uranium by China. This uranium is destined for India's commercial power reactors and would be subject to international safeguards.
Recent evidence seems to indicate that India has the capability to produce the required highly enriched (>90%)uranium needed for the submarine reactor core.
It would also be more economical for India to use low level enriched uranium in its experimental naval reactor. (32)According to P.K. Chari, the former director of the Institute of Defense Studies and Analyses (IDSA) and currently Professor of national Security Studies at the Centre for Policy Research, New Delhi enriched (20%) uranium would find use in a reactor to power submarines. However the use of low level enriched uranium also poses problems. Fuel changes to replace fissioned uranium are needed more often. This poses particular problems for India as there are no suitable facilities capable of handling radioactive materials.
Two different type of reactors would have also been considered. The water-cooled water-moderated reactor (PWR) was designed by BARC and is believed based on Soviet design information obtained form the leased submarine. Some information is known about Soviet reactor design. Naval reactor cores have been described as having 248-252 fuel assemblies depending upon type of reactor. There may be up to a few tens of fuel rods per assembly.
A second liquid metal cooled reactor was probably looked at by Kalpakkam. The pressurized water-cooled reactor is the far better choice and appears to be the reactor chosen for the nuclear powered submarine.
It is now known that China used information obtained about naval ship reactors to help design their first submarine reactor. Information was openly obtained about the West German reactor used on the Otto Hahn and the Soviet reactor used on the Lenin. This information would have surely been available to India.
Indian sources also mention information about a Japanese naval nuclear reactor (Mutsu) and its suitability for use in a submarine.
Most PWR fuel is uranium-aluminum dispersed fuel (cermet) in steel or zirconium cladding. (36)Indian scientists from BARC and the Indian Institute of Technology have published a number of recent papers describing the uranium-aluminum and uranium-zirconium phases.
Enrichment of the PWR core has varied from 21% to as high as 45% for later version cores. A typical first generation core contained approximately 50 kg of U-235 per reactor.
India is very experienced in the design and use of cermet fuel for small reactors. As cited earlier the uranium-aluminum phase diagram has been detailed and the effect of additives such as silicon has been examined. Both Aspara and Zerlina are known to have used medium enriched uranium.
Aluminum clad uranium fuel elements are also in use in both the Cirus and Dhruva reactors. The uranium used in both of these reactors is of the unenriched type and is produced at the Uranium Metal Plant located at Trombay. Fabrication of the fuel elements is done at the Fuel Fabrication Division of BARC. Experience gained in the fabrication of these fuel elements would be invaluable in the design of submarine fuel elements.
If a cermet or aluminum clad uranium is not used then enriched uranium dioxide clad in zircaloy fuel elements may be considered. The Nuclear Fuel Complex at Hyderabad produces zircaloy clad uranium dioxide for both pressurized heavy water reactors and boiling water reactors. Both natural and low level enriched uranium dioxide are used at this facility.
The reactor and its containment vessel are reported to weigh some 600 tonnes. The pressurized water reactor (PWR) will use enriched uranium in the form of plate-type fuel elements.
The steam turbine design and test facilities for use with the nuclear reactor have been set up at Vizag.
Consideration had been given to using a mixed plutonium-uranium oxide fuel in the form of small diameter pins, but that was dropped in favor of enriched uranium in the form of plate-type fuel elements.
Core design, neutronics, power distribution coefficients and criticality calculations all are performed by BARC. Calculations are done in-house using codes developed by both BARC and Kalpakkam scientists. A locally designed supercomputer (PARAM) using parallel processing computers may aid in these efforts, although American and Japanese supercomputers are available for use. (42)Techniques have also been developed at the Advanced Numerical Research and Analysis Group to improve processing speeds of computers by exploiting parallel processing.
According to Kotta Subba Rao Indian nuclear scientists under the guidance of Drs. Ramanna, Srinivasan, and Iyengar have been trying since 1971 to build a nuclear submarine reactor. Three different reactor designs were evaluated. The first was rejected in late 1976, the second in 1979 and the third in 1981.
Problems have existed in the design of certain safety features. An important item in submarine nuclear reactors is the design of the control rod insertion and withdrawal mechanism. This may have been responsible for the radiation leaks aboard the leased Soviet submarine which lead to the reported death of at least one Indian scientist. It is known that India tried to buy a rod worth minimizer ((RWM) used by reactor operators to guide and monitor the proper sequences for the withdrawal and insertion of control rods. The sale was denied.
The control rod technology for use with the rod worth minimizer has been well developed by India. They are able to adequately separate hafnium from zirconium and have also evaluated the worth of hafnium as compared to cadmium for use in control rods. The use of liquid poison systems has also been evaluated.
It has also been reported that the Russian submarine-design bureau Rubin is cooperating in developing the nuclear submarine's 190 MW PWR. Russian engineers have been working with DRDO on the design since 1991.
Even thought India possesses much experience in reactor design and fuel fabrication, construction of the reactor does not appear to gone much past the land based prototype stage. The major holdups appear to be the lack of a suitable harbour facility for handling radioactive materials, lack of an adequate supply of highly enriched uranium, reactor integration and design problems and financial considerations.
The PWR failed tests at Kalpakkam in November and December 1995. The failures were believed to be caused by "several integration and fabrication problems" that have yet to be solved.
In June of 1996 it was reported that the program suffered further setbacks following additional failed tests of the reactor. Problems in fabricating the containment vessel have also occurred.
In July of 1996 it was reported by Delhi All India Radio that "India has successfully developed a nuclear-powered submarine for the navy. The submarine named the Advanced Technology Vehicle was tested successfully somewhere in the East coast recently."
Underwater tests on the reactor were scheduled for late 1996 but are on hold till problems encountered during the earlier tests are resolved.