A-1 (nuclear Reactor)

The A-1 nuclear reactor was the first Soviet plutonium production reactor, built and operated at the Mayak Production Association from 1948 for the Soviet atomic bomb project. It was affectionately named "Annushka" by project scientists.

Design

It was designed as a light water-cooled, graphite- moderated reactor ( LWGR), with an initial power level of 100 MWt (megawatts thermal). Its design and purpose were similar to the B Reactor, the first industrial-scale US plutonium production reactor. The Soviet nuclear program had extensive espionage on the Manhattan Project, and program chief Lavrentiy Beria pushed for direct replication of Manhattan designs at every step. Due to concerns that the Mayak facility was in range of US Boeing B-29 Superfortress bombers, the reactor was to be sheltered underground in a pit, similar to F-1. Unlike the US B reactor, which used horizontal loading of uranium and irradiation slugs, Soviet scientists successfully pushed for a vertical design. This became the forerunner of the RBMK design.

Construction

The uranium and graphite material used in the reactor underwent purity testing at the F-1 nuclear reactor. It was composed of 1050 tons of graphite, and 120 to 130 tons of natural uranium.

Operation

Lead Soviet nuclear physicist Igor Kurchatov brought the reactor to criticality on 8 June 1948. It began operation on 19 June 1948. Plutonium metal was first separated from its spent fuel on 16 April 1949. It was the only source of plutonium for the first Soviet nuclear test, RDS-1, on 29 August 1949.

It was the second-ever nuclear reactor in the USSR(after the F-1 in Moscow), and represented many of their firsts, including first large-scale plutonium production and first water-cooled.

During its operation, it suffered many issues leading to shutdown and repairs. These included corrosion of the aluminium channel liners and fuel element cladding, swelling and breakage of uranium rods, fuel melting, rods fusing into the graphite, and leakage of cooling water into the graphite core.

Two partial meltdowns and a graphite fire occurred in June and July of 1948. Following a series of leaks and fuel damage in late 1948, beginning in January 1949 a full reassembly was attempted to salvage the reactor. Uranium slugs were removed after five months of operation, at temperatures over . Many were partially melted or otherwise corroded. It was not known at the time they also gave off radiation doses in the megacurie range. There was also exposure to gasseous fission products. Workers handled irradiated materials, sometimes directly, and suffered injuries including burns, amputations, and radiation sickness. 173 workers were known to have developed Plutonium Silicosis(an invariably fatal disease) and several hundred received doses of radiation of between 100-400 REM. A significant discharge of radiation into the Techa river following this was also linked to over 200 Chronic Radiation Sickness cases.

Kurchatov himself received hazardous doses during the cleanup of the 1949 meltdown, which very likely contributed to his health decline in 1950, stroke in 1954, and death in 1960 at age 57.

See also

* B Reactor, first US plutonium production reactor
* Windscale Piles, first UK plutonium production reactor
* Marcoule Nuclear Site, site of first French plutonium production reactor
* Dimona Nuclear Centre, site of first Israeli plutonium production reactor
* CIRUS reactor, first Indian plutonium production reactor
* Khushab Nuclear Complex, site of first Pakistani plutonium production reactor
* Jiuquan reactor, first Chinese plutonium production reactor
* Nyongbyon Nuclear Scientific Research Center, site of first North Korean plutonium production reactor

References

Further reading

* ''Dark Sun: The Making Of The Hydrogen Bomb'' by Richard Rhodes ()
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{{Soviet Atomic Bomb Project
Nuclear weapons program of the Soviet Union
Nuclear power in Russia
Graphite moderated reactors
Nuclear weapons infrastructure