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Of course I share Wren's concerns about depleted uranium and (with caveats)
nuclear power, but the article has a point that I don't understand.  They
cite cesium-137 as the villain.  But the "Chart of the Nuclides" (I know, a
publication of the nuclear industry) tells me Ce-137 has two isomers, a
ground state with a half-life of 9.0 hours, and a metastable state with a
half-life of 1.43 days.  That's 225,482 half lives for the long-lived
isomer, which means less than 10exp-99 of the stuff is left (underflow in
my calculator).  I can accept that some sheep are still radioactive
(especially since the number seems to be declining in an explicable way),
but doesn't something else have to be the source?  Maybe something that
decays into Ce-137 but is itself hard to detect?

Anybody know what's up?  (Marvin, are you there?)

Best,

Dick



At 05:58 PM 5/23/2004, you wrote:
>Until nuclear power sites can be safely decontaminated I am against
>nuclear power.  And while I'm spouting off, who gave the U.S.
>permission to use depleted uranium?  Who is trying to prevent that?
>Voting Bush out won't do it because it was used in Kosovo.
>
>I don't mean to sound so brusque but I've been spouting off all morning
>in letters and the adrenalin hasn't subsided yet.
>
>Wren Osborn
>
>Scottish Sheep Still Contaminated By Chernobyl
>By Rob Edwards
>Environment Editor
>The Sunday Herald - UK
>5-22-4
>
>
>It happened 2500km away and 18 years ago, but it is still contaminating
>Scottish sheep with levels of radioactivity considered unsafe to eat.
>
>After the nuclear reactor at Chernobyl in the Ukraine exploded and
>spewed
>radioactivity over most of Europe in April 1986, people were assured by
>the
>authorities that its effects would be seen off in a matter of weeks.
>
>But new figures released by the government show just how misguided those
>assurances were. Today 14 farms covering 16,300 hectares of southwest
>and
>central Scotland are still subject to restrictions on the movement and
>slaughter of radioactive sheep.
>
>The concentrations of radioactive caesium-137 from Chernobyl in the
>animals' muscles still exceed the safety limit of 1000 becquerels of
>radioactivity per kilogram. Farmers have to mark con taminated sheep
>with
>indelible paint, and must wait until they fall below the limit before
>they
>can have them slaughtered for food.
>
>"It is incredible that a small number of Scottish farms are still under
>restriction 18 years on from an accident that occurred hundreds of miles
>away," said James Withers, the spokesman for National Farmers' Union
>Scotland (NFUS).
>
>"The initial advice in 1986 was that the effects would be over in a few
>weeks. It is obviously extremely frustrating and disappointing for the
>individuals concerned."
>
>Ten of the farms with sheep restrictions are in East Ayrshire, three
>are in
>Stirling and one is in East Renfrewshire. The farmers have not been
>named.
>Similar restrictions on the movement and slaughter of sheep still apply
>down south. In Wales they cover 359 farms totalling 53,000 hectares in
>Snowdonia and the north, while in England they affect nine farms
>totalling
>12,000 hectares in West Cumbria.
>
>The information was given by ministers in response to recent questions
>in
>the Commons from anti-nuclear Labour MP for Blaenau Gwent, Llew Smith.
>"Chernobyl showed how nuclear accidents are both deadly to those in the
>area immediately affected, and have an impact thousands of miles away,"
>he
>said. "I strongly believe that all nuclear power should be scrapped.
>
>"It has turned out to be the most costly and certainly the most
>dangerous
>means of generating fuel."
>
>Chernobyl was the world's worst nuclear accident. Errors by control room
>staff in an old and poorly designed Soviet-era reactor led to a blast
>which
>ripped apart the building.
>
>Over several days a massive cloud of radioactivity blew over western
>Europe, falling to earth wherever it rained. Caesium-137 and other radio
>active isotopes got into the soil and were then taken up and recycled by
>grass and plants.
>
>As a result, grazing animals, particularly those in rainy upland areas,
>became contaminated. As well as sheep, high levels of caesium-137 were
>detected in deer and grouse.
>
>Chernobyl also triggered an epidemic of thyroid cancers among children
>in
>Ukraine, Belarus and Russia. According to the World Health Organisation,
>the accident released 200 times more radioactivity than the US atomic
>bombs
>which devastated Hiroshima and Nagasaki in 1945.
>
>In the months immediately after the accident, more than 2000 farms in
>Scotland were subject to sheep restrictions. But by 1991 this had
>dropped
>to 60, and by 2001 to 18.
>
>Farmers affected are compensated under the 1986 Sheep Compensation
>Scheme.
>The government has paid out 2.8 million to Scottish farmers, including
>330,000 over the past five years.
>
>"Our primary concern is to ensure public safety," said a spokesman for
>the
>Scottish Executive. "Monitoring of sheep on affected farms will continue
>until radioactive caesium levels comply with internationally agreed
>standards."
>
>According to environmentalists, there are lessons to be learned from
>Chernobyl's legacy. "When nuclear power plants go wrong they tend to go
>wrong in a big way," said Duncan McLaren, chief executive of Friends of
>the
>Earth Scotland.
>
>"The fact that Scottish farmers today are still feeling the impacts of
>this
>accident should be a warning to all those who think that nuclear power
>deserves a second chance."
>
>He said two of the countries that have just joined the European Union 
>Lithuania and Slovakia  are still relying on old Soviet-style reactors.
>And that the Euratom Treaty which underpins the EU obliges them to
>pursue
>nuclear power.
>
>"Instead of asking these countries to increase their capacity in
>dangerous
>nuclear power we should be assisting them to shut these plants and move
>towards safer, cleaner forms of energy production," McLaren argued.
>
>He added: "In the run-up to the European elections the public should
>challenge candidates as to whether they support replacing this outdated
>treaty with something that will prevent future Chernobyls."
>
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