4. Nuclear explosions

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Nuclear explosions

• 7.1 History
• 7.2 Novaya Zemlya Geography and inhabitation
  • 7.2.1 Two test sites
• 7.3 Atmospheric test explosions
  • Fallout from atmospheric test explosions
• 7.4 Underground test explosions
  • 7.4.1 Discharge of radioactivity from underground test explosions
• 7.5 Underwater test explosions
  • 7.5.1 Civil nuclear explosions
• Endnotes

The Soviet Union performed 715 nuclear test explosions between 1949 and 1990. Of these, 215 were detonated in the atmosphere between 1949 and 1962. Between 1963 and 1990, 500 underground nuclear test explosions have been performed. Three underwater nuclear test explosions have been executed on the western coast of Novaya Zemlya. There were two major fields for nuclear test explosions in the Soviet Union: Semipalatinsk in Kazakhstan and Novaya Zemlya in the Arctic. In addition, there were three minor fields for nuclear test explosions: Azgir and Astrakhan in Kazakhstan, and at Orenburg between the river Volga and the Ural mountains. A nuclear bomb has been used at least once during a military exercise outside these established test fields, possibly at Orenburg. The 715 nuclear explosions include 115 "peaceful" nuclear explosions, some performed on the Kola Peninsula. The only test field of Russia is situated at Novaya Zemlya at the time being, but has not been used since the demise of the Soviet Union.

7.1 History

The Soviet Union’s project of building an nuclear bomb was initiated by orders of Joseph Stalin shortly after the US bombing of Hiroshima and Nagasaki in 1945. The project was led by the head of the KGB, Lavrenti P. Beria. [1] Construction of the first plutonium-producing reactor started in 1946 in Mayak in South Ural. The reactor was put into operation on the 19th of June 1948. Scientists at the radiochemical factory of Mayak soon managed to create the first plutonium ball of a diameter of 10 centimetres. [2] This was used in the first Soviet nuclear bomb, detonated at Semipalatinsk 29th of August 1949. The bomb, Joe I, was named after Joseph Stalin. Mayak became the largest centre of production (five reactors) of arms material in the Soviet Union. Arms material was also produced at the three shut-off towns of Belojarsk (two reactors), Seversk (also known as Tomsk-7) (five reactors) and Dudovono at Krasnojarsk (three reactors). Plutonium, thorium and uranium were assembled in nuclear- and hydrogen bombs at Arzamas-16 (420 kilometres east of Moscow). In all, 15 reactors have been in operation in the Soviet Union for the purpose of creating materials for bombs. From 1949 to 1993, approximately 45,000 warheads were produced in the country. [3] 60 different types of bombs were developed, with an explosive force from a couple of kilotons to many megatons.

Between 1949 to September 1955, 16 nuclear bombs were detonated at Semipalatinsk. At this point, research on hydrogen bombs had already come far in the Soviet Union under the leadership of, among others, Andrei Sakharov. [4] The hydrogen bombs were far more powerful than the nuclear bombs the Soviet Union had detonated so far. Semipalatinsk was unfit for testing of bombs of this kind, as the test field was situated close to inhabited areas. The Soviet Union was in need of a test field far from inhabited areas. During the mid-50’s, the first nuclear weapons were placed aboard submarines and surface vessels, and testing of these on sea targets became necessary. Novaya Zemlya satisfied both of these needs, and a test field was established by decree of 31st of July 1954. [5] The first nuclear detonation on Novaya Zemlya (of Joe 17) took place on the 21st of September 1955. The bomb was detonated 100 feet below the surface in Chernaya Bay on the south-western coast of Novaya Zemlya.

Between 1955 and 1990, 132 nuclear bombs have been detonated on Novaya Zemlya. At Semipaltinsk, 467 nuclear bombs have been detonated. The explosive force of an nuclear bomb is measured in kilotons or megatons. A kiloton corresponds to the explosive force of 1,000 tons of TNT. The combined explosive force of all the 715 Soviet nuclear detonations from 1949 to 1990, is approximately 500 megatons. The combined explosive force of the 132 bombs tested at Novaya Zemlya is 470 megatons, or 94 per cent of the combined explosive force of all Soviet nuclear detonations.

7.2 Novaya Zemlya Geography and inhabitation

Novaya Zemlya is the northern extension of the Ural Mountains which divide the European and Asian continents. Novaya Zemlya is made up of two islands divided by the Matochin Straight. The two islands are 900 kilometres long put together, and cover approximately 82,179 square kilometres. There are a number of small islands, covering a surface of approximately 1000 square kilometres put together. Most of the northern, and parts of the southern island, is covered by glaciers. The permafrost reaches 300 to 600 metres under the ground. The rock of Novaya Zemlya is brittle, and has deep crevices. [6] The highest mountain of Novaya Zemlya is 1,547 metres above sea level.

The first inhabitants on Novaya Zemlya arrived during the stone age. [7] The first Nenets-families settled down on Novaya Zemlya in 1877. [8] There were two main areas of settlement on the southern island, Belochaya Bay on the western coast, and Rossanaya Bay on the southern tip. A meteorological station was built in 1882 at Karmakulakh by the Mototchin Straight. In 1922, 72 reindeer were transported from the mainland to Novaya Zemlya by the Nenets, but keeping of tame reindeer proved to be a failure. The reindeer escaped northwards and mixed with the native wild reindeer flock. The Nenets subsisted on fishing and hunting. Following the decision to use Novaya Zemlya for test explosions of nuclear bombs, the 104 Nenets families were deported to the mainland, mainly to the Petshora Tundra and the town of Narjan Mar.

There are two major military settlements on Novaya Zemlya today. There is a town of approximately 4,000 inhabitants at Belochaya Bay. The inhabitants are mostly military personnel employed at the test fields, and their families. Just east of the town lies the 2,400 metre-long Rogachynovo Airport. The other settlement is situated at the Mototchin Straight, where there is a considerable harbour also serving vessels of the Northern Fleet. There is still a meteorological station at the Matotchin Straight.

Novaya Zemlya is part of the county of Arkhangel’sk, but has been under military administration since the test sites were put into use in 1954. In 1991, the administrational responsibility was, in theory, transferred back to the county authorities of Arkhangel’sk. For all practical purposes, the army is still in command on the archipelago.

The closest area of settlement of any significance on the mainland, is the town of Amderm, 280 kilometres east of the test site. The Norwegian county of Finnmark lies 900 kilometres south-west of Novaya Zemlya.

7.2.1 Two test sites

There are two test sites on Novaya Zemlya, one at Chernaya Bay (southern field) on the southern island, and one by the Matotchin Straight (northern field) dividing the northern and southern islands. All atmospheric nuclear explosions were performed at the northern test site. The southern test site was in use for two years, from 1973 to 1975. The largest geological difference between the southern field and the northern field is the presence of high mountains and deep valleys by the northern field, while the landscape is relatively flat at the southern field.

As previously mentioned, 132 nuclear bombs have been detonated on Novaya Zemlya. 86 of these were atmospheric test explosions performed from 1957 to 1962. 43 underground test explosions were executed from 1963 to 1990. Three test explosions were underwater and were performed from 1955 to 1961. At least two of the atmospheric test explosions were nuclear bombs blasted aboard naval vessels just above the surface in the Barents Sea west of the Matotchin Straight.

7.3 Atmospheric test explosions

The nuclear bombs detonated in the atmosphere over Novaya Zemlya were dropped by airplanes, or shot out as missiles either from land or from submarines. Bombs dropped from airplanes were equipped with a parachute in order to let the planes reach a safe distance before the detonation. The airplanes took off from airports on the Kola Peninsula. Nuclear missiles detonated over Novaya Zemlya were launched in Central Asia or the White Sea region. In the Barents Sea and by Novaya Zemlya, these missiles were shot down and detonated by ABM’ s (Anti Ballistic Missiles).[9]

The atmospherical test explosions over Novaya Zemlya were performed during two periods. The first atmospherical test explosion over Novaya Zemlya was undertaken on the 24th of September 1957. By the 10th of October that year, three bombs had been detonated. During February and March 1958, six bombs were detonated. This is the only time nuclear bombs have been detonated on Novaya Zemlya during the first six months of the year. From the 20th of September to 25th of October 1958, 15 more bombs were detonated. Resistance to atmospheric test explosions increased among Russian arms engineers after 1958. Andrei Sakharov was one of the most noted opponents of atmospheric test explosions. He claimed there were no scientific reasons to perform repeated test explosions of bombs of megaton-sized explosive forces. [10] No Soviet test explosions took place between the 3rd of November 1958 and the 1st of September 1961.

Test explosions were resumed in 1961. The decision to resume test explosions followed the tense political relations developed between the US and the Soviet Union during the course of 1961. After the summit meeting between Nikita Khrustshev and John F. Kennedy in Vienna, June 1961, the Berlin Wall was raised and the political climate of Europe cooled to a considerable degree. Khrustshev called for a meeting between the leaders of the Communist Party, the government and the foremost bomb constructors of the Soviet Union on the 10th of June 1961. Khrustshev opened the meeting with the following decision:

In connection with the changes in international relations and the fact that the combined amount of test explosions of the Soviet Union is considerably inferior to that of the US, we (the Soviet Union) will resume the test explosions during the autumn of 1961 and achieve a de facto increase of our nuclear power and demonstrate to the imperialists what we are capable of.[11]

Between the 10th of September and the 4th of November 1961, 24 bombs of megaton-sized explosive force were detonated. During this period, bombs were being detonated almost every second day. The explosive force of these bombs ranged from 20 to 30 megatons. The worlds most powerful hydrogen bomb was detonated on the 30th of October 1961. The bomb had an explosive force of 58 megatons, or almost 6,000 times more powerful than the Hiroshima bomb. The bomb was dropped by an aircraft, and detonated 365 metres (1,200 feet) above the surface. The shock wave produced by this bomb was so powerful, it went thrice around the earth. The mushroom cloud extended almost 60 kilometres into the atmosphere. Resulting downfall was measured over the entire northern hemisphere. A flash of light could be observed all the way to Hopen in the Norwegian Sea, Sør-Varanger in the Norwegian county of Finnmark and by the Inari Lake in Finnish Lappland. [12]

Test explosions with several bombs of megaton-sized explosive force continued during the autumn of 1962. 32 bombs were detonated over Novaya Zemlya between the 5th of August and the 25th of December. 9 bombs were detonated during the Cuba crisis in October 1962. The Soviet Union, Great Britain and the USA signed the Moscow Treaty on the 5th of August 1963, banning test explosions in the atmosphere, outer space and under water. The treaty became operational on the 10th of October 1963. Negative effects of fallout following test explosions on both humans and the environment were causes for the creation of this treaty.

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No. Date                    Time   Explosive
                                   force
---------------------------------------------
1   24th of September 1957  09.00  Mt-size
2   6th of October 1957     08.58  Unknown
3   10th of October 1957    06.55  Small
4   23rd of February 1958   -      Mt-size
5   27th of February 1958   07.59  Mt-size
6   27th of February 1958   10.24  Large
7   14th of March 1958      -      >1 Mt
8   20th of March 1958      -      Small
9   22nd of March 1958      -      Medium
10  20th of September 1958  -      -
11  30th of September 1958  07.50  Medium
12  30th of September 1958  09.55  Medium
13  2nd of October 1958     08.00  Moderate
14  2nd of October 1958     09.01  Moderate
15  5th of October 1958     06.00  -
16  10th of October 1958    07.51  Large
17  12th of October 1958    07.53  Mt-size
18  15th of October 1958    07.51  Mt-size
19  18th of October 1958    09.51  Mt-size
20  19th of October 1958    07.27  Small
21  20th of October 1958    08.20  Mt-size
22  22nd of October 1958    08.21  Mt-size
23  24th of October 1958    08.03  Mt-size
24  25th of October 1958    08.20  Large
25  10th of September 1961  09.00  Several Mt
26  10th of September 1961  -      Some Kt
27  12th of September 1961  10.08  Several Mt
28  13th of September 1961  -      Small
29  14th of September 1961  09.56  Several Mt
30  16th of September 1961  09.08  Medium
31  18th of September 1961  07.59  Mt
32  20th of September 1961  08.12  Mt
33  22nd of September 1961  08.01  Mt
34  2nd of October 1961     10.31  Mt
35  4th of October 1961     07.30  Several Mt
36  6th of October 1961     07.00  Several Mt
37  8th of October 1961     -      Small
38  20th of October 1961    -      Several Mt
39  23rd of October 1961    08.31  25 Mt
40  25th of October 1961    08.33  1 Mt
41  27th of October 1961    08.30  Small
42  30th of October 1961    08.33  58 Mt
43  31st of October 1961    08.29  Several Mt
44  31st of October 1961    08.38  1 Mt
45  2nd of November 1961    08.41  Small
46  2nd of November 1961    -      Small
47  4th of November 1961    07.20  Several Mt
48  5th of August 1962      09.09  30 Mt
49  10th of August 1962     09.00  1 Mt
50  20th of August 1962     09.02  Several Mt
51  22nd of August 1962     09.00  Mt
52  25th of August 1962     09.00  Several Mt
53  27th of August 1962     09.00  Several Mt
54  1st of September 1962   12.40  -
55  2nd of September 1962   -      Mt
56  8th of September 1962   10.18  Mt-size
57  15th of September 1962  08.02  Several Mt
58  16th of September 1962  10.59  Several Mt
59  18th of September 1962  08.29  A few Mt
60  19th of September 1962  11.00  20 Mt
61  21st of September 1962  08.01  A few Mt
62  25th of September 1962  13.03  25 Mt
63  27th of September 1962  08.03  >30 Mt
64  7th of October 1962     16.32  Medium
65  22nd of October 1962    09.06  Several Mt
66  27th of October 1962    07.35  Medium
67  29th of October 1962    07.35  Medium
68  30th of October 1962    -      Medium
69  1st of November 1962    06.30  Medium
70  3rd of November 1962    08.31  Medium
71  3rd of November 1962    -      Medium
72  18th of December 1962   -      Medium
73  18th of December 1962   -      Medium
74  20th of December 1962   -      Medium
75  22nd of December 1962   -      Medium
76  23rd of December 1962   11.15  A few Mt
77  24th of December 1962   10.44  Unknown
78  24th of December 1962   11.11  20 Mt
79  25th of December 1962   13.35  A few Mt
---------------------------------------------
Mt=megaton(s)  Kt=kiloton(s)

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Photo: Model of the worlds biggest nuclear device (58 megatons) which were detonated over Novaya Zemlya 30 october 1961

Fallout from atmospheric test explosions

The test explosions performed by the Soviet Union, USA, Great Britain, France and China, make up the largest source of radioactive pollution observed today in the counties of Murmansk and Arkhangel’sk. The downfall can be traced over the entire earth. The combined radioactivity of downfall caused by test explosions is hard to estimate, but it is assumed that a couple of thousand kilos of plutonium have been released into the atmosphere between 1945 and 1984. France halted their atmospheric test explosions in the Pacific in 1980, while China continued until 1984 at Lop Nor.

The radioactive cloud of an atmospheric test explosion can be dispersed over an enormous area before the fallout reaches the ground. E.g. more fallout following test explosions on Novaya Zemlya was discovered on the western coast of Norway, than in the county of Finnmark, [ 13] as the rainfall on the western coast is more considerable than in Finnmark. The atmospheric test explosions over Novaya Zemlya have given Norwegians an average radioactive dose corresponding to what they were exposed to following the Chernobyl incident of 1986. [ 14] Certain sections of the population received considerably higher doses, notably the reindeer-keeping Lapps of Finnmark.

The downfall created by test explosions on Novaya Zemlya was a source of considerable unrest among the Norwegian authorities. During the autumn of 1961, all civil defence stations north of Saltfjellet measured levels of radioactivity three times a day. Aircrafts of the air defence undertook measurements above the Barents Sea on an almost daily basis. The Norwegian Health Directory worked out plans for extensive preparedness measures concerning the population of Finnmark in September 1961. [ 15] The plans comprised early warnings to the population to take to air-raid shelters. The population was to be evacuated were the levels of radiation to exceed 100 milliSievert. [16] These plans for preparedness measures were kept secret from the population of Finnmark until 1991.

7.4 Underground test explosions

The first underground test explosion in the Soviet Union took place at Semipalatinsk the 11th of October 1961. [17] The main aim of underground test explosions, is preventing discharge of radioactive gases into the atmosphere. A tunnel is bored vertically into the ground, or horizontally into rock. A bomb is placed at the bottom (or at the end) of the tunnel, which is then walled up. At the detonation, millions of degrees of heat is generated, causing the rock around the bomb to melt and capsuling the radioactivity in a glass-like matter. At Novaya Zemlya, bombs are detonated 300 to 400 metres under ground. [18] At the US test field in Nevada, bombs are detonated 500 to 600 metres under ground.

Since the signing of the Moscow agreement banning atmospheric test explosions in 1963, all Soviet test explosions have been underground. The first underground test explosion at Novaya Zemlya took place on the 18th of September 1964 by the Matotchin Straight. Up until the last explosion on the 24th of October 1990, 43 underground test explosions have been performed on Novaya Zemlya. In comparison, 343 underground test explosions have been executed at Semipalatinsk.

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Photo: Satelite photography of nortern test site at Novaya Semlya; Matotchin-shar. The picture is data-manipulated.

There has been a general tendency for bombs detonated underground at Novaya Zemlya to be larger than those at Semipalatinsk, as was also the case during the time of atmospheric test explosions. The most powerful bomb detonated at Semipalatinsk had an explosive force of 180 kilotons. The explosion of nuclear bombs underground creates significant earth movement, measurable in the same fashion as earthquakes. The explosion of a megaton bomb on the northern field at Novaya Zemlya on the 14th of September 1970, created earth movements that travelled straight through the earth. The earth movement could be registered between New Zealand and the Antarctic, before they returned through the earth and were measured in Canada.[19]

As previously mentioned, there have been two fields for underground test explosions on Novaya Zemlya; the northern field at the Matotchin Straight, and the southern field by Charnaya Bay on the south-western tip of Novaya Zemlya.

The southern field was in use only from 1973 to 1975, and seven test explosions have been performed here. As opposed to at the northern field, tunnels were bored vertically into the ground. The Soviet Union’s most powerful underground test explosion was performed in the southern field on the 27th of October 1973. Three bombs were consecutively detonated. The two first bombs had low explosive forces, while the third one had an explosive force exceeding three megatons. [20] A bomb of an explosive force of two megatons was detonated on the 2nd of November 1974. The two last test explosions on the southern field, were performed just after each other on the 18th of October 1975. The southern field has not been in use since.

There are probably two reasons for the closing of the southern field. With one exception, all underground test explosions of bombs with an explosive force of more than one megaton were performed on the southern field. Explosion of powerful bombs on the northern field have resulted in some significant landslides on the mountainsides. There are no mountains in proximity of the southern field, and detonations can be performed without danger of landslides. This indicates that the southern field was established for the purpose of testing powerful bombs. The USA and Soviet Union signed a treaty in July 1974 banning explosions of bombs with an explosive force of more than 150 kilotons. The treaty became operational from the 31st of March 1976. The southern field was thus no longer of any use.

The other possible reason for closing of the southern field, may be constant leakages of radioactivity to the atmosphere in the wake of test explosions. At the detonation of three consecutive bombs on the 27th of October 1973, earth movement caused the rock covering the bombs to shatter apart, resulting in leakage of radioactive gases.

At the northern field, 36 underground test explosions have been performed. Since 1976, the bombs have had an explosive force ranging from 50 to 100 kilotons. From 1976 to 1990 one or two underground test explosions were performed at Novaya Zemlya each year, with the exception of a 19 month long moratorium from the 26th of July 1985 to the 26th of February 1987. At the time being there is a moratorium lasting until autumn 1994, preventing test explosions.

7.4.1 Discharge of radioactivity from underground test explosions

As previously mentioned, test explosions of nuclear bombs are performed under ground to prevent discharge of radioactivity into the atmosphere. However, radioactivity from approximately 100 Soviet underground test explosions have been observed. [21] This indicates that every fifth underground test explosion in the Soviet Union has resulted in discharge of radioactive gases. The discharges result from the rock above the bomb cracking up all the way to the surface, allowing radioactive gases to seep out. This is called a ventilation. As previously mentioned, a ventilation occurred on the southern field in 1973. Ventilation also occurred at the two last test explosions on the northern field. After the explosion on the 2nd of August 1987, radioactive downfall was observed all over Europe. The highest levels, 5,300 microBq. iodine-131 per cubic metre of air, were measured in Ivalo in Finland. At Skibotn in Norway 1,370 microBq iodine-131 per cubic metre of air was recorded. In Vadsø in Norway, 15Bq/l milk was measured. [22] It is assumed that 0.002 to 0.05 per cent of the radioactive material produced during the test explosion, was ventilated into the atmosphere. The test explosion on the 24th of October 1990 also led to ventilation. Air samples taken at Sundbyberg outside of Stockholm, Sweden, showed concentrations of 10 microBq per cubic metre of air of the radioactive precious gas xenon-133. [23] By tracking meteorological data for this period, the discharge could be traced back to the test explosion of the 24th of October.

The Moscow Treaty of 1963 bans test explosions resulting in downfall outside of the borders of the country performing the test explosion. Several of the test explosions on Novaya Zemlya have thus resulted in breaches of the Moscow Treaty. [24]

7.5 Underwater test explosions

7.5.1 Civil nuclear explosions

The enormous explosive force of the nuclear bomb attracted the interest of the planners of Soviet society at an early stage. From the 1960’s and up to 1988, so-called "peaceful" nuclear bombs were actively used in the Soviet Union. Up until 1988, 115 civil nuclear detonations were performed in what was once the Soviet Union. Nuclear bombs were used for the creation of water reservoirs, canals, mines and gas reservoirs, among other things. Nuclear bombs were also employed for extinguishing gas fires and for seismical research. 41 civil nuclear bombs have been detonated in the northern parts of Russia, most of them in Siberia. [27]

On the Kola Peninsula, 3 civil nuclear bombs were detonated in the mine of Kulpor in the Khibini Mountains, 15 kilometres east of the town of Kirovsk. The first bomb was detonated in 1972, and the two other ( Dnerp) in 1984.[28] The bombs’ explosive force was approximately 1 kiloton. The aim was to increase the amount of extracted apatite-ore for production of phosphate. Phosphate is used for production of artificial fertiliser. There are two entries to the mine. The bombs were placed innermost in the shafts, which were then walled up to prevent leakage of radioactive gases into the atmosphere. Large crevices and piles of rubble can today be observed on the mine’s exterior. [29] Elevated levels of certain isotopes have been registered in a river flowing just below the mine. [30] This river flows into the Imandra Lake. The attempt to utilise nuclear bombs to increase the extraction of ore has not been considered successful, and the mine is now closed. Fear of radioactive pollution was the ostensible reason given for the shutting down of the mine.

Four peaceful nuclear bombs have been detonated in the county of Arkhangel’sk. Three of these bombs were detonated in connection with seismic gauging of the crust of the earth. The first took place by the village of Iljinsko-Podomskoye in the south-eastern part of the county in 1971. The second was detonated in 1984 by the coastal village of Rutshi in the borough of Mezen by the White Sea. The third nuclear explosion in connection with seismic gauging was performed in 1988 south-east of the town of Kotlas. In 1981, a nuclear bomb was detonated in the Nenets Autonomous Region in the far north of the county of Arkhangel’sk. The aim of this explosion was to put an end to a blow-out from a gas well at the Kumzhinskoye Field which had been on fire for several years. The pressure from the nuclear detonation did not extinguish the gas fire.