I have been trying out the precipitation method on 13 samples by now and it’s time for a break and a look at the results. I’m happy! The data is ok since I get almost all the Tc-99 carried away with the Fe2+ precipitate. Good since this work is rather time consuming and there’s a lot of heavy lifting of water bottles. Maybe I will be a strong man after this.

I was thinking that you probably wonder why there is an interest in knowing anything about this artificial radioisotope….I will try to explain. 99Tc is produced in nuclear reactors as a fission product (take a look at the internet about this if you need to). The 99Tc isotope has a very long half-life, about 200 000 years, but it has on the other hand not been existing here on earth before. It is thus a completely new to us humans and it’s behaviour in the environment was not known until we humans started to produce it in the nuclear era. So how does it come from the nuclear reactors to the environment? It does so to some limited amount because some countries send their nuclear fuel to something called reprocessing plants where the fuel is processed in order to use the uranium (and plutonium) which still can be used. In this process some of the radioactive elements are released, among them 99Tc. This is of course some sort of pollution but the levels are usually low. My interest is perhaps not so much to see this 99Tc as a pollutant but as a tracer for water movement. Since we know how much and when the releases occur and of course from what location (the reprocessing plant) we can use some of the radioactive elements as tracers for the water movement. Elements which are not reactive and sink to the bottom because they attach to particles in the water are best suited for this. ⁹⁹Tc does not react much when it occurs in it’s normal form, TcO₄^-, so it is very well suited. It goes where the water current takes it. It is as we would have thrown 1000 bottles in the sea at the reprocessing plant at a fixed time and then can go around in the world to see where they go, how fast and how many that reaches each location in a given time. It’s completely fantastic! Like we are given an extra pair of eyes that can observe things we otherwise not could see. Of course I’m not the first to work with this isotope. There have been many. Some have used it to determine how long time the water takes to go from Europe to the Arctic Ocean (because they were there and measured this isotope in various water samples) and found out that it takes about 10 years. Did you know that some of these currents were discovered long ago but at that time only if they by accident found the bodies of fishermen that have fallen overboard in the North Sea or elsewhere! I think my method is more ‘human’!