It has taken the US decades and several Billion to develop it's current RTG technology. It is not something you can do overnight. It would eat India's entire space budget, leaving none for rockets or space missions.
is a 1950 technology using a heat source and thermocouples.. its very simple .. it will take India less that three months to get it running if needed.. the Russians could easy supply.
You need other elements, Pu-238 has a half life of 87.7 years, and generates a fair amount of internal heat, hence it's current use.
It's worth mentioning that Polonium-210 is a viable alternative,
Not really, the half life is much to short for most the types of missions you would want to use RTGs for. The Soviets used it for heaters on Lunokhod, but they didn't have a long cruise and had a design life of months.
Quote from: Avron on 12/20/2013 01:37 pmis a 1950 technology using a heat source and thermocouples.. its very simple .. it will take India less that three months to get it running if needed.. the Russians could easy supply.And the expertise you possess to make this kind of statement is ....?
RTG's use plutonium-238, weapons use plutonium-239; the processes of producing and refining the two are completely different.
Am-241 and Sr -90 could be used, but they have very significant drawbacks.
The existing stocks of plutonium at Sellafield are more than sufficient for the production of multiple 241-Am-based RTGs each year for a number of years.
Well, Lunokhod-2 worked for 4 months, and didnt die of cold. For applications like exploring lunar poles i think it would be entirely appropriate.
A complete guess, but i think there is a good chance that heaters in Chang'e are polonium as well, especially considering that Chinese specialists apparently have been to Sarov on couple of occasions.
That technique would require you to separate the Pu-238 from the Pu-239, which would be incredibly difficult. Actual production involves neutron bombardment of Neptunium-237 followed by chemical separation, and Np-237 isn't easy to produce in the first place.
The Chinese have said they are using Pu-238. This was discussed quite a bit in the Chang'e thread.
Quote from: Kryten on 12/20/2013 06:30 pm That technique would require you to separate the Pu-238 from the Pu-239, which would be incredibly difficult. Actual production involves neutron bombardment of Neptunium-237 followed by chemical separation, and Np-237 isn't easy to produce in the first place.Np-237 is made how? Take ur old spent fuel rods and add barium and simmer at approx 1200C2 NpF3 + 3 Ba → 2 Np + 3 BaF2
Actually no. Np-237 is separated out using the PUREX process which uses tributyl phosphate (TBP). That solution goes through a number of reductions in oxidation states before being precipitated out as neptunium oxalate and then calcined into neptunium oxide. Then as stated before, the Np-237 is fabricated into targets and irradiated by a high neutron flux to produce Pu-238 which must then be separated, reacted to form PuO2, and then formed into high density compacts before it can be used as a radioisotope heat source. And that is only the start as significant work post compact forming is needed to encapsulate and protect the PuO2. And beyond that, one has to design a structural support around the PuO2 fuel forms to prevent release of the PuO2 under potential accident scenarios as PuO2 is highly toxic. Hardly something one does in 3 months as you claim. But perhaps you have an advanced degree in nuclear physics, inorganic chemistry, materials science or specialty manufacturing that enables you to do all this in 3 months. Hence my prior question; what expertise do you possess to make this kind of statement?
Quote from: GuessWho on 12/22/2013 01:18 pmActually no. Np-237 is separated out using the PUREX process which uses tributyl phosphate (TBP). That solution goes through a number of reductions in oxidation states before being precipitated out as neptunium oxalate and then calcined into neptunium oxide. Then as stated before, the Np-237 is fabricated into targets and irradiated by a high neutron flux to produce Pu-238 which must then be separated, reacted to form PuO2, and then formed into high density compacts before it can be used as a radioisotope heat source. And that is only the start as significant work post compact forming is needed to encapsulate and protect the PuO2. And beyond that, one has to design a structural support around the PuO2 fuel forms to prevent release of the PuO2 under potential accident scenarios as PuO2 is highly toxic. Hardly something one does in 3 months as you claim. But perhaps you have an advanced degree in nuclear physics, inorganic chemistry, materials science or specialty manufacturing that enables you to do all this in 3 months. Hence my prior question; what expertise do you possess to make this kind of statement?A succinct description of a very complex process. You also politely side stepped the fact most of this process has to be handled remotely due to radiation exposure, substantially complicating things. And of course that just gets you to the raw material, not the finished RTG design itself. That said it's an interesting idea that India could act as a niche supplier in this area, enabling any nation that wanted to build a long duration space mission.But not a simple task.
Well, I didn't want to write a book. :-) To complete the story, you also have to consider that everything that remotely touches the process is contaminated and the legacy costs to clean that contamination problem will haunt you for decades.
I doubt that India has either the infrastructure or the expertise to produce and separate the required plutonium isotope, and acquiring those would take a lot longer than three months.
Yes, it works for short duration missions like this, but as I said this is a very narrow subset of the kind of space missions you want RTGs for. A dubious investment unless you are sure you aren't going to want to use them anywhere else.