I live in Pripyat, in the Ukrainian Soviet
Socialist Republic. I came to this quiet woodland region several
months ago, after graduating from the Moscow Engineering and Physics Institute, to work
as a technician at the Chernobyl Nuclear Power Plant. But, my peaceful life turned into unimaginable
chaos just over a week ago, on the morning of the 26th of April, 1986, when the unit
I worked on—the Unit 4 reactor—was destroyed in a horrible accident. As the surrounding areas are evacuated due
to the dangerously high levels of radiation released from the exposed reactor core, I
remain here along with my fellow power plant workers, scientists, firefighters, and many
others... all desperately trying to make sense of what went wrong, while helping to contain
the fires, stabilize the area, and contain the radiation. In this terrible week, I’ve watched many
people suffer the effects of acute radiation poisoning. Headaches, nausea, fever, confusion, seizures… I am fortunate to have not yet experienced
the worst of these symptoms. While only a few died from the actual explosion,
several have died from the radiation. As nuclear engineers and scientists, this
is shocking—no one has ever died as a result of nuclear power’s radiation. Now it is happening by the dozens. We all believed nuclear power to be extremely
safe. As the days go on and I see more of my colleagues
hospitalized, I worry: will I succumb to this disaster, too? However, I hardly have the time or energy
to think about my own health. As I was a part of the team in the control
room at the time of the accident, it is impossible not to feel guilty… Was there something more I could’ve done? I re-play the events of that night over and
over in my mind, and I try to understand what went wrong. The night of the 25th of April, it was business
as usual. I showed up for my shift, and changed into
my white lab coat and cap. Our unit, Reactor 4, was scheduled for routine
maintenance. My colleagues had decided this shutdown would
be a great opportunity to simulate a power outage, and to test whether or not sufficient
electrical power could still be generated to the cooling pumps by the reactor’s slowing
turbine. I knew that they had previously tried and
failed this test just last year; however, new voltage regulators had been developed
since then, so we were hopeful it would be a success this time. Looking back now, how could we have been so
hopeful? No one had coordinated our test plan with
the safety personnel, nor discussed the possible damages. For example, the test required us to shut
off the emergency core cooling system. Perhaps if we had stricter safety protocols
in place, we wouldn’t have even gone through with this test. Or maybe it wasn’t just the test, maybe
it was doomed from the start: the shutdown did not go smoothly. In the beginning, the core’s power levels
fell to unacceptably low levels—around 30 megawatts-thermal (MWt). For our test, the reactor should have been
stabilized at 700 to 1000 MWt—much, much higher. Because of this, some operators wanted to
abort the test. As a relatively new technician, I wasn’t
sure what was the right thing to do… now it is almost painful to think we were so close
to preventing this disaster. But it wasn’t my decision to make, nor was
it any of my co-workers’. The deputy chief engineer, Anatoly Dyatlov,
demanded the operators continue with this test. This created tension in the control room. Some of this faded by 1am, when power did
stabilize—though, only at around 200 MWt. This was technically still too low for the
test. Nonetheless, we continued to prepare for the
test. Cooling pumps were switched on, and the reactivity
decreased. We then began having difficulty with the steam
drum and system pressure levels, so we disabled the automatic trip systems. As parameters stabilized more, we closed the
emergency stop valves. We were about to officially start our test. To begin, I closed the turbine feed valves,
thus allowing the turbine to coast. For a moment, everything seemed just fine. Then, the control rods began to be inserted
into the reactor. These rods work to slow the rate of fission
in the reactor, but we did not have many in use at this time, maybe just 6 to 8—because
we had removed them when the power was too low at the start of the shutdown. This would prove to be a huge mistake. Suddenly, there was a rapid increase in the
power levels of the reactor’s core, and pushing the scram button only made it worse…
runaway power heated the coolant water and increased steam pressure, the control rods
jammed, and fuel elements ruptured. That’s when a powerful explosion ripped
through the core, followed by a second explosion. Black and red dust filled the control room,
latched doors were blown open, the radiation monitors burned out, gauges flickered and
gave confusing readings, and fires broke out in the plant. Everyone was in disbelief, as we soon realized
we did not have protocols in place for this kind of emergency. Dyatlov ordered the smoke exhaust fans and
emergency cooling pumps activated. He believed if we could still get the control
rods into the core, we could still stabilize the reactor. After disconnecting the servo drives to the
rods in the backup control room, he sent a couple of trainees to attempt to manually
force the jammed control rods into the core by hand—a futile task. Nothing worked. Communication lines had been severed, and
we were joined by workers from Unit 3 to describe the damage they’d witnessed. Many of us had been badly scalded by the escaped
steam, which had likely pressurized and created the forceful explosion. Fires had started from ejected fuel in Unit
3 and 4, Unit 4 central hall’s roof had been blown off, and the cooling circuit was
nearly all but gone. Outside, the ground was littered with destroyed
graphite blocks, chunks of concrete, sparking and ripped electrical cables, and fuel. A plume of smoke and debris had been thrown
a kilometer into the air. Dyatlov was in denial—he was certain that
the explosion was simply caused by the emergency tank. But the evidence in the aftermath was clear… We all knew the worst had happened: the top
of the containment structure had blown open, and the reactor’s radioactive core was open
and exposed to the atmosphere. Workers responded quickly to shutdown nearby
Unit 3’s reactor. Off-duty staff were called in for support. Firefighting units arrived. By dawn, many workers had to be taken to the
medical unit due to the radiation poisoning… including Dyatlov. Maybe it is short-sighted and wrong of me
to try and place blame on any of my co-workers’ actions, or even on myself—after all, I
am just a young, junior-level technician. Maybe it is even wrong to put all the blame
on Dyatlov. Maybe others are just trying to be kind to
me, as they know I was in the control room at the time, but many have spoken to me about
their other theories. They say it could be the design of this specific
type of reactor which led to its demise… Though that seems like an even scarier possibility,
because it means there could be even more disasters like this one if we don’t make
corrections to the design. Reactor 4, just like other units at this facility,
was an RMBK class reactor that used enriched uranium as its fuel. These RMBK reactors are common here in the
Soviet Union, but not throughout the rest of the world. Some of the RMBK’s unique features include
graphite moderators—which help to sustain a continuous fission reaction—coupled with
its use of light water to cool the fuel. These reactors produce both plutonium and
electric power. The RMBKs also have something called a positive
void coefficient: when there is an increase of steam in the core, the reactivity increases
as well... making them highly unstable at low power. In contrast to this, most Western reactors
have negative void coefficients, which respond steam increases with a decrease in reactivity. It is this positive void coefficient that
is central to a popular theory among technicians here: That the runaway power output which
led to the ultimate destruction of Reactor 4 was caused by a dangerously large void coefficient,
due to excess production of steam. Some even complain that the containment structure
was insufficient to keep the radioactive core fortified and protected from contaminating
the environment. Still others blame politics. They point out that our leaders—both our
superiors at the plant, as well as politicians—did not prioritize safety, as there were no emergency
preparedness plans nor strict procedures to follow in the event of a meltdown. Many, myself included, believe we are too
isolationist from the rest of the world’s scientific community. Perhaps, it was just a perfect storm of design
weaknesses, poor decisions, and a lack of oversight. Either way, I don’t know how we will sort
through this mess to solve it precisely… What does the world think of us? Do Western scientists think we are inept because
of this horrible disaster? As we have been so isolated from our fellow
engineers and scientists during the Cold War, I can only hope that this disaster will warm
our relations with the Western scientific community. Together, we can better search for answers,
support, and prioritize safety. Have we ruined the health and safety of thousands
here in our town, or of the millions that will be in the path of this massive, wind-blow
trail of radioactive debris? As the fuel’s uranium atoms shatter, they
break down into radioactive iodine, which has now been released and deposited into the
surrounding area’s earth and water. This radioactive iodine that makes its way
into fresh milk from the dairy farms here can lead to thyroid problems and cancer. Will civilians across the globe, as they read
news headlines about this alarming event, now become opposed to the use of nuclear energy? As a scientist, this is perhaps the most unfortunate
thought. Nuclear energy promises to be cleaner, cheaper,
more efficient, and safer… Despite these last horrible days, I believe
it still can be the future of energy. But will public outcry prevent all this? Before this disaster, I had been so excited
to come to work everyday, but now this plant looks like a hellscape. It has been over a week and the fires continue
to burn. Tons of neutron-absorbing and thermal-controlling
compounds, such as dolomite, boron carbide, lead, sand, and clay are dumped from helicopters
and onto the damaged reactor. I work with other technicians and scientists
to investigate what went wrong, and to engineer a system that could feed cold nitrogen to
the reactor space. Hopefully, this will cool temperatures and
slow the radionuclide release. We also plan to entomb the reactor’s remains
with concrete, in order to lock in the radiation from further contaminating our atmosphere
and groundwater. There is so much work to be done, and much
of it quite dangerous—but we must act quickly. As I return for another day to help, I’m
exhausted. Suddenly, I develop a terrible, pounding headache. Is it just stress? I’ve been taking potassium iodine pills,
as a precaution against the radiation, for the past several days. But it seems it’s no longer enough… I’m weak, dizzy, and… I can’t even remember what I’m doing here. Someone notices that I look confused, and
a medic comes to evaluate me. He confirms what I feared: that, now, I am
suffering serious effects of acute radiation poisoning, and must be hospitalized… I can only hope I am luckier than those we
have lost so far.
Again it's all straight from Medvedev's book, with Dyatlov's argument & denial, and a power surge before pressing AZ-5. 3.6/10 -- not terrible, not great.