Hell slime seems to be the equivalent of a weapon of mass destruction, so it is probably a code for the atomic bomb, first developed in the West. The Soviet atomic bomb project used spies in the West from 1942 to 1945, and the first Soviet bomb was tested in 1949. So Red and Vulture are analogous to atomic spies. The novel’s Carrigan Lab accident seems like the USSR’s Kyshtym Disaster of 1957, a military-industrial mishap that is currently the third-worst nuclear accident after Chernobyl (1986) and Fukushima (2011).

After World War II, the Soviet Union lagged behind the US in development of nuclear weapons, so it started a rapid research and development program to produce a sufficient amount of weapons-grade uranium and plutonium. The Mayak plant was built in haste between 1945 and 1948. Gaps in Soviet physicists’ knowledge about nuclear physics at the time made it difficult to judge the safety of many decisions. Environmental concerns were not taken seriously during the early development stage. All six reactors were on Lake Kyzyltash and used an open cycle cooling system, discharging contaminated water directly back into the lake. Initially Mayak was dumping high-level radioactive waste into a nearby river, which was taking waste to the river Ob, flowing further down to the Arctic Ocean. Later Lake Karachay was used for open-air storage.

A storage facility for liquid nuclear waste was added around 1953. It consisted of steel tanks mounted in a concrete base, 8.2 meters underground. Because of the high level of radioactivity, the waste was heating itself through decay heat (though a chain reaction was not possible). For that reason, a cooler was built around each bank containing 20 tanks. Facilities for monitoring operation of the coolers and the content of the tanks were inadequate.

On 29 September 1957, the cooling system in one of the tanks containing about 70–80 tons of liquid radioactive waste failed and was not repaired. The temperature in it started to rise, resulting in evaporation and a chemical explosion of the dried waste, consisting mainly of ammonium nitrate and acetates (see ammonium nitrate bomb). The explosion, estimated to have a force of about 70–100 tons of TNT, threw the 160-ton concrete lid into the air. There were no immediate casualties as a result of the explosion, but it released an estimated 20 MCi (800 PBq) of radioactivity. Most of this contamination settled out near the site of the accident and contributed to the pollution of the Techa River, but a plume containing 2 MCi (80 PBq) of radionuclides spread out over hundreds of kilometers. Previously contaminated areas within the affected area include the Techa river which had previously received 2.75 MCi (100 PBq) of deliberately dumped waste, and Lake Karachay which had received 120 MCi (4000 PBq).

In the next 10 to 11 hours, the radioactive cloud moved towards the north-east, reaching 300–350 kilometers from the accident. The fallout of the cloud resulted in a long-term contamination of an area of more than 800 to 20,000 square kilometers (depending on what contamination level is considered significant), primarily with caesium-137 and strontium-90. This area is usually referred to as the East-Ural Radioactive Trace (EURT).

At least 22 villages exposed to radiation from the disaster, with a total population of around 10,000, were evacuated. Some were evacuated after a week but it took almost 2 years for evacuations to occur at other sites