230 likes | 240 Views
This article discusses what we can learn from the Fukushima nuclear accident about effective accident management. It explores the medical effects of X-rays, Hiroshima-Nagasaki bombings, Windscale, Three Mile Island, and Chernobyl incidents. The article also delves into multistage theories of cancer and the potential long-term health consequences of exposure to radiation.
E N D
What we should have learned from past experienceWhat can we learn from Fukushimaabout accident managementRichard WilsonDepartment of Physics Harvard UniversitySeminar on Planetary EmergenciesErice, Sicily August 20th 2011
Medical X raysHiroshima-NagasakiWindscaleThree Mile IslandChernobylalsoMultistage theories of Cancer (Sir Richard Doll)
During 1900-1970 • Medical advantage of X rays was so great • It outweighed disadvantages • BUT • advantage could be the same but • disadvantage (dose) was reduced a factor of 150 • International Commission on Radiation Protection (ICRP) and Physicists
Hiroshima-Nagasaki • Then: • Atomic Bomb Casualty Commission (ABCC) • Now: • Radiation Effects Research Foundation (RERF) • UNSCEAR 100,000 or so papers • Most people died of blast • 5000 died or will die of excess radiation • Prompt radiation • What is the effect of lower dose rate? • (only real study is that at Techa River)
Acute Radiation Sickness • An acute dose from dose within a few days • LD50: 250 to 400 Rem (2.5 Sv – 4 Sv) • LD50 after blood transfusion: 350 to 600 Rems • (3.5 – 6.0 Sv) • (Canadian Louis Slotin, May 1946) • Evacuate to avoid acute dose Chronic effect • If just below acute dose 10% -20% • increase of cancer probability • (increasing if exposure continues)
Windscale 1957Well known iodine cycle:Iodine drops on grass cows eat grassconcentrate in milk babies drink milkconcentrate in thyroidGraphite reactor caught fire.Iodine releasedmilk impounded for 100 miles downwindno casualties
Studies on Stress are not definitive5% increase of cancer probability is plausible • Human studies: • “Handbook of psychophysiology” • By John T. Cacioppo, Louis G. Tassinary, Gary G. Berntson. • “Health effects of relocation following disaster: a systematic review of the literature” • By Lori Uscher-Pine, Disasters, 33(1):1-22 (2009) • Animal studies : • NTP control groups • “Megamouse” study
Three Mile Island • Core melted but inside containment • Hydrogen explosion inside containment • Probably iodine came out in water as HI • (no harm) • Unauthorized NRC man panicked and called for evacuation • Kemeny commission noted stress due to evacuation
Chernobyl • Secrecy was involved: those advising not to drink milk were reprimanded • Cesium 134 and 137 were and are the main culprits. • Integrated dose was mostly after a few days • Evacuation from Pripyat after 36 hours. Estimated dose for a Pripyat resident 5 Rems • Chistalogovka was 3 days late • Less than 1% strontium 90 released little plutonium
Distinction between compulsion and voluntary evacuation not clear. • In USSR: “What was not forbidden was compulsory” • Just before Chernobyl • National Radiological Protection Board (UK) • had careful report on criteria for reentry • Panic in Europe (Stockholm) set rules for reentry • (reindeer meat: British objected: welsh lamb, etc)
Integrate by taking peak and half width • Integrated Dose at main gate • through March 16th • 2-3 Rems (0.02 -0.03 Sv) • Nowhere near enough for Acute Radiation Sickness TEPCO regained some control • Maybe 5 5 Rems in year; • less than 1% increase in cancer rate. • No need to evacuate
Highest Integrated Dose about • 15 Rems (0.15 Sv) • (in open – 4 times less indoors) Increase in cancer probability: 1 to 2 % (more for younger, less for older) Compare to 5% x e^(+/- 1) from stress
Chairman Gregory Jaczkotestimony in US CongressMarch 17th 2011 • Recently, the NRC made a recommendation that: • Based on the available information that we have, that for a comparable situation in the United States, we would recommend an evacuation to a much larger radius than has currently been provided in Japan. As a result of this recommendation, the ambassador in Japan has issued a statement to American citizens that we believe it is appropriate to evacuate to a larger distance up to approximately 50 miles.
Should you compulsory evacuate? • Should you assist a voluntary evacuation? • Should you encourage sensible efforts to keep the dose down? • How do you stop irresponsible comments? • Gregory Jacsko on March 17th • Physicians for Social (Ir) Resposibility
What other doses are there? Calculate your own. • http://www.new.ans.org/pi/resources/dosechart/ • (mine was 2.4 Rem last year - 2 CAT scans) • Many actions can give anyone a dose of 1 Rem: • A single chest x ray in a major hospital as late as 1960. • A CAT scan today. • 3 months average public dose • 1/25 of what a Chernobyl clean up worker got • 1/100 of an astronaut's allowed dose. • About the dose I got in 1991 from a day at Chernobyl mostly inside the sarcophagus
Earthquake in Haiti • 200,000 • Earthquake and Tsunami in Japan • 30,000 • Fatal cancers from Chernobyl in next 60 years (calculated ) • 4,000 - 8000 • In Belarus, Russia and Ukraine • 20,000 world wide • Fatal cancers calculated from Natural Background (including medical) exposures in US • 6,000 per year • Cancer fatalities from Three Mile Island • 0.7 calculated for the Kemeny Commission • “0 - 5,000 adverse health effects of evacuation”from Fukushima.