Chernobyl Nuclear Power Plant CIA Files - Paperless Archives

The So\"ict Nuclear Power
Program After (he
Chernobyl' Accident
Short-Term Consequences of the Accident
The accident that destroyed reactor unit 4 of the
Chernobyl' nuclear power plant in late April 1986 had
many and \~ried consequences-from the tra~ie human
costs (sec inset) to marginally greater fossil-fuel
consumption, safety upgrades on Chernobyl'-t)'pe rcactors,
and some reexamination of the commercial
nuclear program in the USSR_
The Acdden!: Prescription for Oluster
The So\"ie! acciden! repor! filed with the International
Atomic Energ)' Agency (IAEA) indicates thall~e
errors that doomed unit 4 began on 25 April when
technicians started a poorly executed experimcnt 10
lest the emergency electricily supply to the reactor.
Major violations of the proccdures for reactor opcralions
were commi!tcd, such as switching off the
emergency shutdown system and operating the reactor
with too many control rods withdrawn. These
human errors, coupled with a design flaw that allowed
reactor power to surge when uncontrolled steam
generation beean in thc core, set up the conditions for
t he accident.
The final moments of the accident occurred in a
period of about 40 seconds at 0123 l(\cal time on­
S~turday, 26 April. Opcrator errors had put the
reactor in an unstable condition, so rcactor power
incrcascd rapidly whcn the er.pcriment be~an" Subsequent
analysis of the SOl'iet data by US expcrts
suggests the power surge may ha\'e accelerated when
the operators tried an emeriency shutdown of the
reactor.' According to SOl'iet data, the energ), re­
Icased was, for a fraction of a second, 350 times the
ra ted capacity of the reactor. This burst of energ,
rC5ultcd in an instantaneous and violent sur£c of heat
and pressure, rupturing fuel channels and releasing
I An u[lCrt IUm ,uscmblcd br Iht Dcplflmcnt or Encrn bJ.s
c'-.:lIeJ.lcd the firul hours of unit". fot dCI3i1S sec DOE/NE-0016.
NO\'cmocr 1986. Rcpo/'l Q/lhc US. DqQI"/ft1CNI 0/ 1:'n('rf.Y",' Trunr
Ana/po ,if '''~ Chanob)"l"-l Atumic £nutJ" Statioll .-ia,-dcn(
Sl'qUC'f1(,(
Th~ Ilumun Costs tJ/llre Clrcrnoby/'Accitienl
The 3/ initial casualties rt:Sltlling/rom rhe ~.Tploslol/
rhal d~stroy~d ulllr 4 ... iIl ullimald)' ace-ounl/or 011/.1'
a lIIillor pari tJ/lh~ hUll/lUI ,oll o/th~ Chunob)'1'
disaJlu. Tk'O PVIt'U plane ,,'orkus "-cr~ killtd immetiialdy,
alld burns and hlgll radIation 'xpo!urc!
~.'cnlually claimed rhe Ii.·~s 0/ aMlhu 29 ptop/~n:asl
0/ Ilrml fircmrJ/ and sile ~I/Itrgtn()' pasonnc/.
SOI'i~1 doclors nporred Illal n~arl)' 300 p~oplt u­
cd"cd ~nough radiation /0 uquirc hospitalizalion.
These illdil-iduals ",ill apcrltnet subslaneial addllional
risk 0/ cancu. (
Longer (UIII heallh conseQlul/cts in th~ USSR ... i11
fewll/rom radivaclive conralllina(i~n spr~ad b)' tire
accidenl over an area 0/ aboul 1,000 sQuau kilometers"
Many Ihousands 0/ persons .. ·tre exposed ro lhis
,adlatloll (or wtll b~ apoStd 10 uSldual amOll/llS 0/"
radialion as dailyroulints are fetstablishtd), increasing
Ihdr 10llg-term risk 0/ canur. Tlris eanar
threat pO us uniqlle mtdical and psychological prob-
1