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REINFORCED
' CONCRETE
3 Y2
FEET
T~ICK
WITH
STEEL
LINEA •
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COOLING
WATER
9-FOOT-THICK
CONCRETE SLAB
NUCLEAR ENERGY- THE ODDS AGAINST CATASTROPHE
Electnctty from the atom ts produced very much llke that trom
conventional power plants. wtth one eructa! difference. the
source of heat An atomtc reactor denves tls heat from the fls–
sioning ol uranium atoms located in fuel rods containtng mil–
lions of small pellets of uranium dioxide
In mosl reactors. the lleat generated by nuclear ftssion ts car–
ned away by a pnmary cooling system
ot
pressurized water
(2.500
psi). Upon leav1ng the reactor tlle
600
F water 1n the
pnmary system 1s passed through a heat exchanger, where it
transfers its heat to a secondary system (see d1agram). The
water
1n
the secondary system 1s at a lower pressure and va–
porizes as steam. which dnves the turbines and generators of
the power plant.
In nuclear power generation. experts say the worst malfunc–
J¡on that could occur would be a "double-ended guil lottne
break" that would completely sever one of the ptpes carry1ng
the pressurized water of the pnmary cooling system (see ar–
row).
lf
such a failure occurred. the reactor would be automatl–
cally turned off by spec1al control rods. Yet the restdual heat in
the reactor core would sttll require continued cooling
lf
emer–
gency cooling pumps also fa1led. the core's temperature would
soar above
5000
degrees. vaporiz1ng the remaining water and
The
PLAIN TRUTH August
1976
productng a deadly cloud of rad1oacttve steam and other gases.
Eventually the dome could rupture and the ent1re reactor core
would melt tnto the ground.
Thousands of people could be k1lled 1n such an acctdent, and
thousands more would be expected to develop cancer from the
exposure to released radioactivtty Hundreds of acres of con–
taminated land mtght need lo be sealed off for many decades
What are the odds of such a disaster? The so-called Rasmus–
sen Report. recently revtsed. has concluded that
100
nuclear
plants would be expected to expenence an acctdent 1nvolv1ng
1000
or more fatalthes only once m every
1
mtllton years - the
same probability that a meteonte tmpact would kili the same
number On the other hand, the report concludes that with
1
00
reactors operattng, the chances of a reactor meltdown ts a not–
so-remote
1
tn
200
per yeár.
What are an tndtvtdual's chances of being ktlled by a nuclear
acctdent? The report says less than
1
tn 5 btllion per year. Thts
compares to about 1 in
4000
that an 1ndtv1dual w111 be k1lled 1n
an auto accident 1n a gtven year By any standard, the odds of
5 btllion to
1
seem pretty favorable , and hopefully these odds
will grow even more favorable as safety techn1ques are further
refined.
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