Atoms and ashes

10,000 evacuated, 270,000 exposed
wikipedia: 20 Mcuries of radioactivity
- previous intentional dumping of 3 Mcuries into Techa river and 120 Mcuries into Lake Karachay

wikipedia: 300 Kcuries xenon-133, 20 Kcuries iodine-131, 600 curies cesium-137

wikipedia: 14 μSv to 2M people, compared to 3100 μSv annual natural dose (8.5 μSv/day) 13 Mcuries noble gases, 15 Curies iodine-131, 1e10 curies remained in reactor
TMI unit 1 returned online, and shut down permanently on September 20, 2019. The fuel assemblies were removed to a storage pool (onsite?). No idea about the current radiation levels in the spent fuel and the removed unit 2 reactor, or in the containment buildings.

RMBK reactor bol'shoi moshchnosti kanal'nyi, high-powered channel-type reactor 1GWe
blueprints 1967, deployed December 1973 Leningrad Nuclear Reactor Station at Sosnovyi Bor
- 41 mi west of Leningrad, 46 mi from Estonia, 57 mi from Finland, 140 miles from Helsinki, 150 miles from Tallinn
1980, close to 10 RMBK-1000 reactors in the USSR
vulnerable to steam explosions AND graphite fires
Ancient Chernobyl 15 km away, new city Prypiat 2 km away, construction began 1970
1st went critical 1

977, 2nd 1978, 3rd 1981, 4th 1983, two more under construction, six planned across Prypiat river

No emergency cooling system, no accident localization system, no sealed containment building for reactors 1 and 2.
- reactors 3 and 4 had emergency cooling and accident localization but no containment because of vertical fuel rods and the overhead crane needed to service them
graphite tips on scram rods caused activity spike
positive void coefficient, loss of coolant increases activity
Operators were not told about vulnerabilities, followed instructions for 13 years
First RMBK accident at Leningrad station November 1975 because of positive scram, (up to) 1.5 Mcurie release, kept secret even to plant operators.
Chernobyl director, chief engineer had only coal plant experience more later

AtomsAndAshes