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Homer Simpson 'nuclear waste spill' panic at nuke sub base!

Almost as bad as dropping a luminous watch in the sea!

National news outlets, citing "secret" Ministry of Defence (MoD) documents, are reporting that "serious safety breaches" and "leaks of liquid radioactive waste" have occurred at the Faslane nuclear submarine base. It's sort of true, but one would release many times more radioactive material into the Clyde by dropping a luminous watch into it.

The story comes to us courtesy of anti-nuclear campaigner-slash-journalist Rob Edwards, writing in the Guardian and also providing expert commentary (audio) on his own research. Channel 4 sexes things up even more (vid), referring on TV to a "secret" report that "we've obtained", plus leaks of "radioactive liquid", "untreated waste" and "secrets kept" from the local community.

In fact none of the documents involved are classified even to the routine "Restricted" level applied to almost all internal MoD paperwork - two levels below Secret. The very few that even have an MoD header on them are marked "Unclas" - Unclassified. They were all obtained by a standard Freedom of Information Act request submitted, not to the MoD, but to the Scottish Environmental Protection Agency (SEPA) - the whole lot can be downloaded from SEPA as indistinct image pdfs here.

The three "leaks of liquid radioactive waste" refer, not to some kind of green glowing ooze of the sort routinely released at work by Homer Simpson, but to water: possibly containing varying but low levels of tritium, a heavy isotope of hydrogen. Submarines at Faslane routinely need to offload water with tritium in it, or water which hasn't been subject to any radiation itself but which has run through the same pipework and so may have picked up some tritium.

The procedure for dealing with this water is that it is pumped out of the sub at the quay and then moved to a tank a few hundred metres along the shore. From that tank, it is dumped into the Gareloch, the deep sea inlet on which Faslane is situated. Before release into the loch it is filtered, but this treatment doesn't affect or remove the tritium - it's to remove mundane contaminants such as oil.

After filtering, the water is dumped straight into the loch with tritium still in it. As far as radioactive contamination goes, you might as well just pump it straight out of the submarine into the surrounding water.

This procedure is fully approved by SEPA, reasonably enough because the amounts of radioactivity involved are tiny. One can legally buy or sell a luminous-dial wristwatch containing 10 GigaBecquerels (GBq) of tritium in the UK: the MoD only needs to dump an average of 8 GBq of tritium a month at Faslane. Even SEPA says a TeraBecquerel (100 watches' worth) of tritium going in the loch per annum is fine, more than ten times what the MoD actually does.

Realistically you could release many times the annual SEPA Faslane tritium limit every day and the Gareloch would remain radiologically* safe for humans to drink - the Gareloch holds on the order of half a trillion litres of water, and the tides flow in and out twice a day. Water is judged safe to drink by the European Union up to a hundred Becquerels of tritium per litre.

So what happened with Rob Edwards' "three leaks of liquid radioactive waste", then?

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