Forty years on, Chernobyl is in trouble again

April 26, 1986 marks the worst civilian nuclear disaster in history when reactor 4 at Chernobyl Nuclear Power Plant exploded, blowing
the top off the reactor and discharging huge amounts of radiation into the atmosphere. Fast-forward four decades and a 2025 drone
strike that set fire to the shelter protecting the shattered remains is expected to need hundreds of millions of dollars of repairs

CHERNOBYL NUCLEAR
POWER PLANT
(pictured in 2020)

N
N

200m
220 yrds

ROTATED VIEW

Plant was intended to have 12
nuclear reactors and would
have been largest in
world had accident
not occurred

Reactor 1
1977-1996

Reactor 2
1978-1991

Reactor 3
1981-2000

Reactor 4
1983-1986

(Duration of
operation
shown)

Machine room:
Contains turbine
generators

Helicopters dump sand, clay
and lead onto reactor to
quench fires – takes
15 days

Chernobyl,
Ukraine*

Radioactive
contamination
spreads across
Europe, shown
on May 3,
1986

Schematic
drawing†

1
2
3
4 
5
6

1. Apr 26, 1986:
Operators, conducting
test to observe reactor
at low power, remove
most control rods (used
to slow nuclear reactions)
and lose control of flow of
coolant. RBMK-1000 reactor’s
flawed design makes it unstable at low
power levels, further exacerbated by key
safety features being deactivated

2. 01:23am‡: Power surge causes
two explosions, blasting top
of reactor through roof
and spewing tonnes
of radioactive
fallout far and
wide

Sarcophagus

3. Apr 26-May 9:
Cleanup operation
begins. Approximately
500,000 workers drafted in,
some braving lethal radiation
levels, with 31 firefighters and
technicians dying within days
from acute radiation sickness.
Some 115,000 people
evacuated from surrounding
area

4. May-Nov: Hastily
constructed concrete
sarcophagus built to encase
ruins of reactor – suppresses
95% of radioactive material
inside it

5. Nov 14-29, 2016:
New Safe Confinement
(NSC) shelter slides into
place, enclosing reactor and
original sarcophagus, which is now
crumbling and in danger of collapse.
Later, additional structural supports are
added to sarcophagus to shore it up

Additional
supports

New Safe
Confinement:
Steel, with
polycarbonate
inner panels
Cost: ~$2.5bn

6. Feb 14, 2025: Shelter hit
by Shahed-136 – Iranian-
made attack drone of type
used by Russia against
Ukraine – punching hole in
NSC (breaking hermetic seal)
and causing fire that burns
for 17 days. Cost of repair
estimated to be around
$600m

Extent of fire
damage within
double-skin of NSC

Hole

*Part of Soviet Union at that time (modern country boundaries shown). 
†There were actually 211 control rods
‡Local time
Sources: Radio Free Europe/Radio Liberty, Financial Times, AFP, BBC, Graphic News Archive, Getty Images
Satellite image: Google Earth Pro
© GRAPHIC NEWS