Light water graphite reactor
The light water graphite reactor (LWGR) is a design of nuclear reactor that uses purified graphite as a neutron moderator and light water (H2O) as a liquid coolant. Due to the superior moderating properties of graphite, natural uranium can be used as a fuel, avoiding enrichment. The design was developed during the Manhattan Project, in a horizontal layout, first used in the 1944 B Reactor, also the world's first large-scale reactor. The Project's Hanford Site constructed nine LWGRs in total for plutonium production, used throughout the Cold War.[1] The Soviet Union subsequently developed a vertical design for use in military plutonium production reactors, constructed at Mayak, the Siberian Chemical Combine in Seversk, and the Mining and Chemical Combine in Zhelenogorsk.[2] The Soviet Union also developed civilian power prototypes eventually into the RBMK design, the only widespread use of LWGRs for commercial nuclear power plants.[3] RBMKs use slightly enriched uranium (<2% 235U). China's nuclear weapons program also developed two military plutonium production LWGRs.[4] Reactors used for plutonium production in the nuclear weapons programs of the United Kingdom, France, and North Korea used gas-cooled reactors (GCRs) moderated by graphite, while those used by Israel, India, and Pakistan were believed to be heavy water reactors (HWRs).[citation needed]
| Reactor | Country | Criticality date | Initial power
(MWth) |
Notes | Refs. |
|---|---|---|---|---|---|
| B Reactor |  United States
|
26 September 1944 | 250 | First LWGR, twin D and F reactors built under Manhattan Project | [1] |
| A-1 |  Soviet Union
|
10 June 1948 | 100 | First Soviet plutonium production reactor; in Mayak | [2] |
| AM-1 | Soviet Union
|
6 May 1954 | 30 | First LWGR to generate electricity | [5] |
| AMB-100 | Soviet Union
|
1 September 1963 | 286 | SCWR test? | [6] |
| N Reactor | United States
|
8 December 1963 | 4000 | Also Hanford Site, shutdown following Chernobyl disaster | [1] |
| AMB-200 | Soviet Union
|
10 October 1967 | 530 | SCWR test? | [7] |
| Chernobyl Reactor 4 | Soviet Union
|
26 November 1983 | 3200 | Reactor exploded in 1986, worst nuclear accident in history | [8] |
| Jiuquan reactor |  China
|
1966 | ~250 | China's first plutonium production reactor, military use | [4] |
| Guangyan reactor | China
|
1973 | ~250 | Third Front facility, military use | [4] |
See also
[edit]References
[edit]- ^ a b c "Plutonium: The First 50 Years". FAS Project on Government Secrecy (1991-2021). 1994-09-30. Retrieved 2025-06-17.
- ^ a b Rhodes, Richard (1995). Dark Sun. New York, NY: Simon & Schuster. p. 276. ISBN 978-0-684-80400-2.
- ^ Panov, Aleksei; Trapeznikov, Alexander; Trapeznikova, Vera; Korzhavin, Alexander (2022). "Influence of operation of thermal and fast reactors of the Beloyarsk NPP on the radioecological situation in the cooling pond. Part 1: Surface water and bottom sediments". Nuclear Engineering and Technology. 54 (8). Elsevier BV: 3034–3042. doi:10.1016/j.net.2022.03.004. ISSN 1738-5733.
- ^ a b c Zhang, Hui (2011-04-25). "China's HEU and Plutonium Production and Stocks". Science & Global Security. 19 (1): 68–89. doi:10.1080/08929882.2011.566469. ISSN 0892-9882. Retrieved 2025-06-17.
- ^ "APS 1 Obninsk". World Nuclear Association. 1951-01-01. Retrieved 2025-06-17.
- ^ "Beloyarsk 1". World Nuclear Association. 1958-06-01. Retrieved 2025-06-17.
- ^ "Beloyarsk 2". World Nuclear Association. 1962-01-01. Retrieved 2025-06-17.
- ^ "Chernobyl 4". World Nuclear Association. 1979-04-01. Retrieved 2025-06-17.