Monday, May 17, 2021

Chernobyl Still Burns

Like a dying camp fire, but a lot more dangerous, the Chernobyl Nuclear Power Plant is smoldering from a uncontrolled nuclear reaction deep in an inaccessible basement of the ruin. The plant blew up in 1986 creating the worst nuclear disaster in history. "Liquidators"--the name reflects the human sacrifice involved--put the external fire out, eventually. They could not remove the fuel rods inside the ruined building. Unit Four was covered by a movable steel shield in 2018, but the original concrete sarcophagus is now old and could crumble in an explosion. [photo] Over time the shelter, as the concrete and steel sarcophagus is called, leaked rain water into the destroyed reactor, which had the perverse effect of increasing neutron counts. Sprinklers were installed to shower Unit Four with gadolinium nitrate solution to absorb neutrons that might cause a chain reaction to initiate. The spray cannot penetrate some basement areas.

The room where the suspected nuclear reactions are occurring is full of radioactive rubble concealing a hellish mush of fuel material, cladding, graphite, and sand that flowed into the lower parts of the plant like lava where it hardened. One hundred seventy tons of uranium fuel is thought to be trapped inside, about 95% of the original fuel load. Rising neutron levels indicate a chain reaction is occurring, raising the possibility of another, but smaller explosion if the embers are left to fully ignite. Neutron levels have been steadily rising in room 305/2 for four years. Removing the nuclear fuel material is problematic as radiation levels are too high for humans to access. Robots might be able to drill down into the rubble and install boron control rods to absorb neutrons. Ukraine hopes to present a plan for controlling the nuclear fire by September. A hard lesson: nuclear fusion is a fire from hell that does not easily die. [photo credit: Getty Images/ TASS]