"On the occasion of every accident that befalls you, remember to turn to yourself and inquire what power you have for turning it to use." - Epictetus
I recently stumbled upon a Wikipedia article about a radiological incident that I was completely unaware of. This event happened in a remote northern part of Russia during the cold war, so it's not too surprising that it slid under the radar. It's an interesting read. I'll try to decipher the Wiki article for non radiation-worker readers, and provide a few good Google Earth images.
Where it happened: On the Kola Peninsula in Russia, just 37 miles (60km) from the border with Norway. At the time, the facility was called Soviet Naval Base 569. The facility entered service in 1961, and the incident took place in 1982.
There are three nearby submarine bases, as well as the closed city named Zaozyorsk - formerly known as Severomorsk-7 and Murmansk-150. Closed cities in Russia are similar to the arrangement made during the US war-time situation at Los Alamos, when the atomic bomb was in development. Closed cities are areas where entire families are located within a secure perimeter. These are high-security zones with restricted access, where sensitive industries are located, or secretive research is performed.
Lets zoom in a bit, so that we can get a better feel for the place where this event took place, before discussing the details. Click on photos to improve resolution.
Below: Northern Europe is left, and Russia is to the right. The location of the event was in a fjord on the northern coast of the Kola peninsula.
Below: Zooming in a little closer on the Kola peninsula.
Below is the region of interest, with three submarine bases pinned, the closed city of Zaozyorsk, and the place this post is about, Guba Andreyeva.
Guba Andreyeva was the storage facility that housed spent nuclear fuel for the Soviet Northern Fleet, and now you can probably already see where this post is heading...
The fjord where this took place is called Zapadnaya Litsa, pictured below.
A bit closer in, we can see the Zapadnaya Litsa Submarine base to the right, a minor submarine repair facility (with a rusty floating drydock) at the bottom left, and the spent fuel storage facility, Guba Andreyeva.
Today, the spent fuel storage facility looks like this: Modern buildings, well-kept, and properly fenced.
In 2003 it looked like this. The half-sunken ships show the level of institutional neglect.
So what happened here in 1982? About 700,000 TONS (22 billion gallons, or 83 billion liters) of highly radioactive spent-fuel storage pool water leaked into the fjord.
The design of the facility was not up to the task of holding the weight, heat, and corrosiveness of the stored fuel and pools. And this brings us to "Building #5", the building that housed the fuel.
Below: A modern western spent fuel pool. Fuel elements are stored in specially designed racks that allow natural circulation to remove heat from each element. We will soon learn what was going on in the dilapidated and neglected Building #5.
Building #5 contained two spent-fuel pools, which were very long and narrow. 200ft by 10ft (60m x 3m), with a depth of 20ft (6m). The depth was to provide enough water to shield personnel above from the highly radioactive fuel elements. Which of the long, narrow buildings in the above Google Earth images was Building #5 is anyone's guess. I am at a loss to figure out which one it was.
Interestingly, the fuel element storage was not done in racks, as we see in the image above. Instead 5-7 spent fuel elements were placed in a steel drum, and the drum was suspended above the bottom of the pool on heavy chains. This arrangement also allowed circulation of water completely around the hot fuel elements.
Unfortunately, due to poor design of the suspension system for the drums, they frequently dropped off their chains and fell to the floor of the pool, resulting in drums and fuel piling up dangerously on the bottom of the pool. This could have led to an uncontrolled nuclear reaction, but apparently a critical mass never formed. Perhaps workers spread the fallen fuel elements out with long poles.
I will now do some block-quoting from the actual Wikipedia article.
"The first time I came there, I was shocked: I have never seen such a nightmare, did not even conceive it was possible. Just imagine an enormous black windowless building atop of a cliff. Entry into the building #5 was decorated by deformed trucks previously used for carrying nuclear fuel and half-torn-down heavy gates. Inside, the building was dilapidated, electric equipment in dangerous condition, the roof letting through sights of the Aurora Borealis, and, most terrifyingly, colossal beta particle contamination levels and traveling gamma waves reflected from plates and walls. Building #5 was completely radioactive inside. If a drop of water happened to fall on your head, you had to be decontaminated for a long time, since the drop contained tens of thousands of beta particles."
Timeline of the nuclear accident (from Wikipedia)
- "The right-hand pool in building #5 started leaking in February 1982. Finding cracks in the metal coating required diving into the pool, which was out of the question due to the gamma radiation levels in the vicinity of the nuclear waste drums reaching 17,000 R/h. An attempt to eliminate the leak was made by pouring in 20 sacks of flour, thus filling the cracks with dough. However, the leak continued, and the service personnel discovered icing on the right side of the building. The method was clearly ineffective. The leak's volume was estimated from the size of the icing to be about 30 L/day. A commission consisting of naval specialists and the building's designers was created in order to determine the cause of the leak. The most likely cause was determined to be destruction of the pool's metal coating.
- In April 1982, a study showed that the leak now let through 150 L/day, with the icing on the right side of the building having gamma-ray levels of 1.5 R/h.
- In April 1982, the basement part of the building was filled with 600 m3 (21,000 cu ft) of concrete. The effort proved ineffective.
- At the end of September 1982, the right-hand pool's leak reached dangerous levels of 30 tonnes per day. There was a risk of exposure of the top parts of the nuclear fuel assemblies, potentially leading to subsequent irradiation of the service personnel, as well as contamination of the entire aquatic territory of the nearby Zapadnaya Litsa bay. In order to safeguard against gamma radiation, it was proposed to cover the pool with iron-lead-concrete covers and then move the nuclear fuel assemblies into dry storage.
- In November 1982, a sharp decline in the amount of leakage was detected, it was now 10 tonnes per day. Experts attribute this to the building sagging under the weight of the iron-lead-concrete covers mounted over the pool, weighing thousands of tonnes. It was later determined that it was only good fortune that prevented the collapse of the whole building.
- December 1982 saw completion of cover construction over the right-hand pool, and the left-hand pool was 30% covered. All of the water from the right-hand pool drained into the bay, and the left-hand pool sprouted a leak of about 10 t/day.
- A special Ministry of Defense commission arrived on 14 February 1983. It confirmed the closing of the repository, except for works related to the cleanup of the accident. No more spent nuclear fuel was loaded in building #5.
- March 1983 through September 1987 saw spent fuel unloaded from the left-hand pool. All of the fuel was unloaded and sent to the Mayak nuclear facility, except for 25 drums, which could not be extracted. They were all buried in boron to capture neutron emissions.
- On 13 December 1989, all of the spent nuclear fuel (about 1,500 drums) from building #5, except for the 25 remaining at the bottom of the left-hand pool, were unloaded. Building #5 was never used for storing spent nuclear fuel again."
A leak in the spent-fuel pool is serious for a few reasons. Obviously you are releasing massive amounts of radioactive contamination into the environment - that is a given. However, you also are losing shielding for personnel as the water level drops. Furthermore, if the water level drops low enough, the fuel can be uncovered. At that point, the fuel temperature can climb above the boiling point of water, and then the fuel can get hot enough to melt itself due to decay heat.
Makeup water for the pool must be of very high purity, so that contaminants do not cause scaling or corrosion. At some point, it became impossible to demineralize enough water to make up for the leakage rate, so the right-hand pool had to be abandoned. Lead and Iron radiation shielding was placed across the pool to temporarily reduce the radiation hazard caused by the loss of water. In the end, all of the water from that pool ended up leaking into the environment, unfortunately.
One of the causes for the pool failure was lack of temperature control in the pool water, or perhaps in the building itself. Ice developed on the surface of the pools, which expanded and cracked the welds. However these guys were cowboys! They figured out a clever (if insane) way of dealing with surface ice on the spent-fuel pool. Quoting again:
"When building #5's repository was designed, it was assumed that the water would be kept at a constant temperature by heat from the nuclear assemblies suspended under the surface. A separate water heating system was thus deemed unnecessary. But the designers were wrong, the harsh Arctic climate covered the pool's surface with a 20 cm (7.9 in) layer of ice in winter. In order to solve this problem, the ice was melted using steam from the boiler, in blatant violation of radiation safety protocol. This was accomplished in the following manner: a hole was drilled in the ice cover, a pipe was inserted into the hole, and steam was pumped through the pipe under the ice, melting it. Radioactive aerosols spread through the whole building, leaking into the air outside."
Two workers ended up in the spent fuel storage pool during the clean-up operation. One worker fell in, and a second worker heroically jumped in to save the first. Seriously, the second guy is right up there with Mother Teresa, in my opinion.
"During extraction of drums from the bottom of the pools, an accident occurred that might have cost two workers' lives. After the left-hand pool was covered with protective lids, cleanup workers cut windows inside them with torches in order to feed in a capturing device that lifted drums from the bottom. The windows were covered with iron sheets to protect the workers from radiation and prevent them from falling in. During this work, one of the workers, a starshina 1st stage, inadvertently stepped onto an iron sheet covering one of the windows. The sheet failed to support his weight, and it dropped with him into the pool's radioactive water. As the worker fell, his legs got caught under some nuclear waste drums, and the water splashed onto the others, who also did not have radiation protection equipment.
From the memoirs of the cleanup effort's leader after the accident, A. N. Safonov:
Everyone present was terrified, knowing there were numerous nuclear waste drums at the bottom, radiating up to 17,000 R/h. Simple arithmetic told me that next to one of those drums, he will receive a dosage equal to 4.7 R/s.
Note: The LD-50/30 for acute radiation exposure is 400 - 450 Roentgens (4 - 4.5 Sievert. LD-50/30 is the statistical probability that 50% of victims will die within 30 days. So just 10 seconds next to one of these drums implies a 50% likelihood of death due to radiation sickness. 30 seconds' exposure would pretty much guarantee a death sentence within a month.
A moment later, another worker, a starshina 2nd stage, heroically jumped into the pool to save his comrade's life. A few seconds later they both surfaced, completely soaked in radioactive water. Witnesses say their faces had expressions of utter terror.
The first worker himself remembers:
In that moment, I thought I was in Hell. When I found myself submerged in radioactive water, and my legs were caught by death ray-emitting drums, death's hot embrace enveloped my body and began to pull my consciousness into a warm daze. In that moment I thought I was only 20 years old and I did not want to die. Just then, my friend and savior Semenov, risking his own life, freed my legs from under the nuclear waste drums, and we emerged at the pool's surface.
Both workers were sent into the showers for decontamination. The dosimeter's arrow kept passing tens of millions of beta decays. Both workers had hair removed from all parts of their bodies, slept separately from everyone else and received food in rubber gloves, since their bodies themselves were now sources of gamma radiation. The dose to which they were exposed is unknown, as their dosimeters sank in the pool.
From the memoirs of A. N. Safonov:
We only managed to wash our bodies from radioactive chemicals by the end of the month. We had to remove the skin on heels and partly on our hands with razors until they bled, since these areas resisted decontamination."
There also may have been two criticality accidents during the clean-up phase at Building #5 sometime between 1983 and 1989.
"When nuclear fuel drums were unloaded from building #5 to be loaded into the dry storage containers, it often happened that cells, deformed from physical impacts and ice, spilled nuclear fuel. The working sailors then used regular shovels to pour the fuel into the cement-encased vertical steel pipes of the storage containers. These actions led to accumulation of critical mass and subsequent uncontrolled chain reactions, glowing from Cherenkov radiation and emitting a buzzing sound, which quickly subsided.
Here is how A. N. Safonov describes this:
This phenomenon was observed by nearby sailors. Of course, we did not file any official reports. The navy usually concealed such information to avoid taking the blame…
Blue-green flashes of light were also observed in the left-hand pool in building #5 during the work on lifting nuclear waste drums from the bottom. That they were uncontrolled chain reactions was confirmed by the physicist, senior lieutenant Leonid Grigorievich Konobritski, who served then in building #5."
Norway has been an important partner in much of the clean-up efforts that have taken place at the Guba Andreyeva spent fuel storage facility. The Soviet era had a crass attitude toward the environment with respect to radioactive contamination - on both sides during the cold war.
There is an excellent article (somewhat dated) about clean-up activities here.
Another more current article is here.
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