This essay offers a commentary on the HBO series, intended for those who watched all five episodes, focusing on the technical aspects but broaching the subject of how humans and societies construe nuclear technology. The creators of this series were not afraid of technical scientific details, as they realized the story had a scientific core wrapped in how humans, as well as the Soviet bureaucracy, responded to complex truths, both politically troublesome and culturally traumatic. Today, Chernobyl remains a cultural touchstone for the dangers of nuclear technology, serving as a comparison for any nuclear accident.Ī popular HBO series, Chernobyl, was aired this summer detailing, and dramatizing, what happened. There was a run on iodine pills and a dramatic increase in elective abortions. The reports from the USSR were not informative, but fission products (ash from the nuclear fission process) were being reported in air samples throughout Europe. The newest reactor (#4) at the Chernobyl site exploded, 50 miles north of Kiev in the Ukraine and only a few miles from the border with Belarus. Timeline for the disaster.Those of us of a certain age remember that the world shook on April 26, 1986. 97% of the health effects are projected to be in the Soviet Union and Europe. suggest 93 million person rem and a projection of 17000 additional fatal radiogenic cancers out of a total of 123 million cancer deaths. Levi gives an estimated long term total exposure of 29 million person rems with an excess of 3000 cancer deaths above the 9.5 million cancer deaths projected in the same population. Thyroid doses from Iodine-131 as high as 250 rem were measured in children from Lelev, 9 km from reactor. About 500 were hospitalized altogether, including bus drivers who evacuated residents." An estimated 24,000 of the 116,000 evacuees received fairly serious radiation doses of about 45 rem. 237 persons were "removed to hospitals with acute radiation syndrome. There were 31 fatalities as of May 1987, all of whom were at the power plant, and most of whom were firemen fighting the blazes following the explosion. About 3-5% of the core inventory of the relatively refractory elements such a strontium, plutonium, and ruthenium were released, much more than from a light water reactor meltdown. The noble gas releases were estimated by Levi to be 45 MCi of xenon-133 and 5 MCi of krypton-85. The cesium release from all of the atmospheric weapons tests is estimated to be about 30 MCi. suggest that essentially all the noble gases and about half of the volatile elements ( iodine-131, cesium-134 and cesium-137) were released. The release was then about 7 million times that at TMI. The total release was around 4% of the total accumulated activity of the core and compares to a release of 15 Ci at Three Mile Island. The cesium is the most serious release in terms of long term consequences. Core detailĬore Detail of RBMK-1000 Reactor Contaminants released in accidentĪ retrospective view of the Chernobyl accident of assesses the total radiation release at about 100 megaCuries or 4 x 10 18 becquerels, including some 2.5 MCi of cesium-137. These soviet reactors are missing such safety features as the 6 to 8 inch steel reactor vessel and the steel and concrete reactor containment dome of the US light water reactors. ".any increase in reactor power increases coolant boiling, which increases the steam void fraction, which in turn increases core reactivity and causes the power to rise even further." ( Chernobyl and Its Legacy, EPRI) This positive void coefficient for the RBMK exists under most operating conditions and makes them particularly difficult to control at low power levels. This means that a void in the water coolant could actually increase the reaction rate. Since the graphite provides the major part of the moderation needed to sustain the chain reaction, the coolant water actually may provide excess moderation. Edwards says there are 15 RBMKs operating in USSR but that the other 40 reactors are similar to US reactors. About half of soviet reactors use graphite moderators. They are in fact similar to that used by Enrico Fermi at University of Chicago's Stagg Field in 1942 to create world's first chain reaction. The four RBMK-1000 reactors at Chernobyl represented crude technology that was 30 years old at the time of the accident. Chernobyl Critical events in the disasterĬhernobyl "Xenon poisoning" of the reaction rate
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |