The following is part of an article that I send out each year with the sodium. It's titled "Lid blown off Dounreay's lethal secret", and is from New Scientist, 24 June 1995 (p6) if you can get hold of old copies. [I'll see if I can scan it and post it here.]
"Early in the morning of Tuesday 10 May 1977 there was a loud explosion at the Dounreay nuclear plant on the north coast of Scotland. The UK Atomic Energy Authority, which runs the plant, had dumped at least 2 kilograms of sodium and potassium down a 65-metre shaft packed with radioactive waste and flooded with seawater.
The results were dramatic. The sodium and potassium reacted violently with the water. The explosion blew off the shaft's huge concrete lid, threw its steel top plate 12 metres to one side, badly damaged the 5-tonne concrete blocks at the mouth of the shaft, and blasted scaffold poles up to 40 metres away. An eyewitness reported a plume of white smoke blowing out to sea. And, as government watchdogs revealed for the first time last week, the ground around the shaft was littered with radioactive particles hot enough to injur and kill. Over the past 18 months, almost 150 such particles have been found on Dounreay's beaches."
The rest of the article goes on about the particles and where they wound up, health effects, and a lot of finger pointing, blaming and denying, but I particularly like those first two paragraphs for classroom use.
And every time I reread this article I wonder "Why??? What were they thinking????? "
I have never had a problem, cut off a 2 or 3 mm cube add to a 500ml beaker of water with a squirt of universal indicator in, it fizz's around the top maybe a little spark or 2 then watch the pH change.
Using more than this is wastful and dangerous!
This is the part that I love most about our job. Sodium is so much fun, and the nature of its unpredictability makes it even more interesting. Bigger chunks = bigger fun.
Bigger chunks = bucket chemistry. Preferably steel bucket in the middle of the sports oval. You need a lot of clearance (and don't forget the all important RA ).
Lyn.
I agree with Ocker - last semester at uni I had a lecturer demonstrate the Group 1 metals reactions with water & because some students urged him, he used a bigger chunk (it wasn't that big either!) - as he was putting it into the water (not IN the water - just NEAR it) it exploded in his face! Luckily he had all the PPE on so he wasn't hurt but it was awful!
And shows how unpredictable Na can be. I won't let my teachers use anything bigger than what Ocker suggests in his post.
Meant to post this weeks ago - why you shouldn't mix sodium, potassium, radioactive waste and seawater!
Combine it with the video clips that Japezz listed in this thread and it could lead to a nice little classroom discussion..... or more requests for bigger lumps of Na. (Insert mad scientist smiley here.)
Dounreay.pdf
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