The 1mSv per year is the max the employees at the dump/recycling plant can be exposed to, so leeching more than that into public water systems seems impossible unless I'm missing something. This comes mainly from solid scale deposits removed from the closed loop systems.
Average employees in German plants seemed to get around 3 mSv/yr on their table.

At Fukushima, According to TEPCO records, the average workers’ effective dose over the first 19 months after the accident was about 12 mSv. About 35% of the workforce received total doses of more than 10 mSv over that period, while 0.7% of the workforce received doses of more than 100 mSv.
The 10mSv was the estimated average exposure for those who evacuated immediately, not the area. Because iodine 131 has a half life of 8 days, the local exposure levels dropped rapidly, but because caesium-137 has a half life of 30 years, contaminated areas will be "hot" for quite a while, and are still off limits as I understand it.

Sort of...., most of the area surrounding Chernobyl is just above background levels after major decontamination including removal of all soil, but many areas closer to the plant are still being measured at well above safe levels to this day, and unapproachable, while others may be visited only with monitoring equipment, dose meters, and only for short times. It's not back to background levels everywhere, with measurements up to 336uSv/hr recorded in enclosed areas and abandoned recovery equipment (the claw used to dig at the reactor for instance)....no where near that low at the plant itself. Places like the nearby cemetery which couldn't have the contamination removed still measure higher than maximum occupational limits for adults working with radioactive material. The radiation levels in the worst-hit areas of the reactor building, including the control room, have been estimated at 300Sv/hr, (300,000mSv/hr) providing a fatal dose in just over a minute.
http://www.chernobylgallery.com/chernobyl-disaster/radiation-levels/

Don't get me wrong, I support nuclear power. I just don't believe in pretending it's "safe". That's how Chernobyl happened....overconfidence and irresponsibility. If we consider it unacceptably disastrous if it goes wrong, we might design plants that can't go wrong...The tech exists.

Your video, Caesium - The most reactive metal on Earth!, has made it into the Top 15 New Videos listing. Congratulations on your achievement. For your contribution you have been awarded 1 Power Point.

This is very cool -- it must be the metal with the next-lowest melting temperature after mercury.

.....aaaaaand a bit of research reveals that Ga melts at 29.8°C, and there are three other "liquid metals" as well: francium (27°C), caesium (28°C), and rubidium (39°C).  Gallium is the only one that is considered non-toxic.

There are also non-toxic metal alloys that are liquid at room temperature, such as gallium-indium-tin, which melts at -20°C.

the obvious question... where can i get caesium?

heh. you can hear the guy whistle in the background when the caesium is put in water.

Tags for this video have been changed from 'alkali, metals, lithium, sodium, potassium, rubidium, caesium, water, reaction' to 'alkali, metals, lithium, sodium, potassium, rubidium, caesium, water, reaction, chemistry' - edited by mauz15

One of these days I'll find a YouTube video of someone dropping Caesium into water.

Actually, we only assume that there was 2 grams of Caesium because they had previously used 2 grams of Rubidium- the amount of Caesium is not mentioned. As for Francium, it is an artificially created element, with a half-life of 22 minutes (if memory serves). That said, however, I'm sure it would be fun!

richard hammond!? the hamster? he sure does get around... and caesium explosion was unbelievable... just 2 grams?

i can't imagine francium.