Plutonium Watch: Tracking Plutonium Inventories

by David Albright and Kimberly Kramer

June 1, 2004

Plutonium is a key ingredient in nuclear weapons, making it one of the most dangerous materials in existence. At the end of 2003, there were about 1,855 tonnes (metric tons) of plutonium in the world in 35 countries. This is enough plutonium for more than 225,000 nuclear weapons.

Civil plutonium is in two basic forms–contained in spent (irradiated) fuel, or in separated (unirradiated) form. Unirradiated plutonium may be in pure form, in the process of being fabricated into mixed-oxide (MOX) fuel, or in fresh MOX fuel. Once it has been irradiated, however, the plutonium in MOX fuel, like the plutonium produced when uranium fuel is irradiated, is contained in spent fuel. The plutonium in spent fuel is considered more proliferation resistant because it is difficult to separate the plutonium from the other radioactive constituents of spent fuel.

Table 1 shows that, of the 1,855 tonnes of plutonium in the world at the end of 2003, 1,700 tonnes were in civil stocks, and 155 tonnes were dedicated to nuclear weapons and other military stocks. Each year, the amount of civil plutonium grows at a rate of about 70-75 tonnes. The military stocks grow only slightly each year. For comparison, stocks of highly enriched uranium are included.

The 1,700 tonnes of civil plutonium are contained in both spent fuel and unirradiated forms. The amount of plutonium in both categories is increasing. Roughly 1,370 tonnes are in spent fuel. About 330 tonnes are in unirradiated forms. The plutonium was separated in civil reprocessing programs or was declared excess to military requirements by the United States, Russia, and Britain.

Plutonium Holdings by Country, end of 2002

Table 2 shows plutonium holdings by country at the end of 2002, the last year for which there is detailed information. In total, about 1,780 tonnes of plutonium were in the world at the end of 2002. Of this amount, there were about 1,625 tonnes in civil stocks, about 1,300 tonnes in spent fuel and about 325 tonnes in unirradiated form. Military stocks comprised about 155 tonnes. India, Israel, and North Korea had a combined total of about one tonne of plutonium dedicated to military purposes.

In a few cases, the figures in table 2 come from official public declarations. For countries that do not declare plutonium holdings, or produce incomplete declarations, ISIS estimates are used. ISIS judges that, without detailed knowledge of plutonium discharges at individual reactors, the country-by-country estimates presented here are uncertain by 10-25 percent. Uncertainty could not be lowered to less than five percent unless each country provided more information about the amount of plutonium discharged in spent fuel, or more information about spent fuel discharges and fuel burn-up.

Civil Separated Power Reactor Plutonium by Country, end of 2002

Table 3 shows the amounts of separated plutonium produced in civil power reactor programs held and owned by 14 key countries at the end of 2002, the last year for which detailed country-specific information is available. Most of the figures come from the official public declarations that nine countries make annually to the International Atomic Energy Agency (IAEA). Several of the entries in the table are estimates, however, because some declarations are incomplete or ambiguous. In addition, India, Italy, Netherlands, and Spain have not made declarations of their separated plutonium inventories to the IAEA or the public.

Most declarations for stocks at the end of 2003 are not yet available from the IAEA. However, based on an assessment of the amount of spent fuel reprocessed and the amount of plutonium used in MOX fuel, ISIS estimates that roughly 235 tonnes of power reactor plutonium were in unirradiated forms at the end of 2003.

Projected Civil Separated Plutonium Inventories

Currently, roughly 15-20 tonnes of plutonium are separated from spent fuel each year, and about 10-15 tonnes of separated plutonium are fabricated into MOX for use as fuel in light-water reactors. In general, the fabrication and use of MOX fuel has not kept pace with the rate of plutonium separation, so the amount of separated plutonium has continued to grow. This trend is expected to continue over the next several years.

Europe’s MOX fabrication capacity has been expanded, and more power reactors are expected to be licensed to use MOX fuel, particularly in Japan. However, intense controversy surrounds commercial reprocessing and MOX use. The completed Sellafield MOX fabrication plant (SMP) in Britain continues to encounter difficulties in obtaining an operating license. The French MELOX fabrication plant may not operate at its full capacity because of government opposition. Japanese power reactors have experienced great difficulty in obtaining approval to use MOX fuel.

Given these uncertainties, projections inevitably vary depending on the assumptions of the fate of the MOX fabrication plants, the amount of plutonium separated, and the number of reactors using MOX fuel. The projections presented here are rather broad ranges that attempt to capture most of the possible futures for plutonium separation and use during the next 15 years. Table 4 summarizes these results for countries with plans to use MOX fuel and countries without firm plans to use MOX fuel. A sobering conclusion is that under a wide variety of reasonable assumptions, total civil separated power reactor plutonium stocks are not expected to decrease significantly in this period. A positive result is that Belgium, Sweden, Switzerland, and likely Germany will reduce their inventories to zero or near zero. However, most countries listed in the table will have to store their plutonium either domestically or overseas for the foreseeable future, absent major initiatives to reduce inventories of separated plutonium.

Military Plutonium

The world’s militaries have significantly less plutonium than civil owners do–some 155 tonnes, not including 107 tonnes declared excess to military needs by Britain, Russia and the United States. For the purposes of this study, excess plutonium is considered part of civil inventories. The amount of dedicated military plutonium is less than 10 percent of the amount in civil inventories. But more than 90 percent of military plutonium is in separated form, and thus more readily usable in weapons. Table 5 lists the inventories of military and excess plutonium in the five acknowledged nuclear weapon states. In the coming years, more military plutonium could be declared excess.

Excess Plutonium Disposition

Table 6 estimates the disposition of US and Russian excess plutonium stocks through their conversion and use as MOX fuel in power reactors. The United States and Russia have each agreed to dispose of 34 tonnes of excess plutonium as MOX fuel.

However, plutonium disposition has gone more slowly than expected. All 68 tonnes of plutonium should be irradiated in power reactors by 2030, although delays could postpone this date further.

Unirradiated Civil Plutonium Projections

The total projected stock of unirradiated plutonium is shown in table 7. By 2020, the total stock is projected to be 285 tonnes, with a range of 230 to 360 tonnes. Compared to a total stock of 330 tonnes at the end of 2003, this result shows that the projected inventory of unirradiated plutonium will be relatively fixed during the next 15 to 20 years.

Table 1: Global Plutonium and Highly Enriched Uranium (HEU), Assigned to Civil or Military Stocks, end 2003, in tonnesa

Category     Plutonium     HEU     Total
Civil Stocks     1,700b     175     1875
Power and Research Reactor Programs     1595     50     
British, Russian, and U.S. Military Excessc,d      107     125 (US only)     
Military Stocks     155     1725     1880
Primary     155     1250     
Naval and Other          175     
Russian HEU declared Excess          300e     
Total     1855     1900     3755

(a) These aggregate numbers are based on an attempt to realistically assign plutonium and HEU to civil or military stocks based on a combination of factors, principally current use and future intended use. The bulk of the plutonium and HEU in military stocks is material in nuclear weapons, reserves, naval and production reactor programs, and in storage from dismantled weapons.

(b) Rounded.

(c) In other tables, the British excess military plutonium is included with civil power reactor values because Britain includes this plutonium in the category of civil, unirradiated plutonium in its INFCIRC/549 declarations to the International Atomic Energy Agency.

(d) Britain and the United States declared that their excess plutonium would be used only for peaceful purposes. The United States made a similar commitment for its excess HEU; Britain did not declare any excess HEU. Russia has made a similar commitment for its excess plutonium, but not for its excess HEU (see note (e)).

(e) Russia has committed to blend down 500 tonnes of HEU to LEU. By the end of 2003, it had blended down 200 tonnes. The remaining 300 tonnes remain in its military stock, probably in nuclear weapons, and not isolated from its primary military stock and committed to peaceful uses. As a result, this stock is assigned to the military stock. As HEU from this category is blended down to LEU, it is removed from this total.

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Table 2: Holdings of Plutonium by Country, end 2002, in tonnesa

Country ____________Civil____________ Military Total
  Irradiated Unirradiated Excess Total    
Argentina 10     10   10
Armenia 1.3     1.3   1.3
Belgium 22 1.8   24   24
Brazil 1.9     1.9   1.9
Bulgaria 8.8     8.8   8.8
Canada 130     130   130
China 4.3     4.3 4.8 9.1
Czech Republic 5.6     5.6   5.6
Finland 11     11   11
France 182 47.9   230 5 235
Germany 64 25.6   90   90
Hungary 7.1     7.1   7.1
India 12 1   13 0.36 13.36
Israel 0     0 0.56 0.56
Italy 4.1 2.4   6.5   6.5
Japan 106 38.6   145   145
Kazakhstan 3.0     3.0   3.0
Lithuania 9.2     9.2   9.2
Mexico 2.2     2.2   2.2
Netherlands 1.2 2.1   3.3   3.3
North Korea 0 0 0.03-0.04b 0.03-0.04
Pakistan 0.9     0.9 0.04 0.94
Romania 2.2     2.2   2.2
Russia 83 37.8 50 171 95 266
Slovakia 7.9     7.9   7.9
Slovenia 2.5     2.5   2.5
South Africa 5.3     5.3   5.3
South Korea 41     41   41
Spain 24.7 0.5   25   25
Sweden 39 0.83   40   40
Switzerland 13 2   15   15
Taiwan 21     21   21
Ukraine 38     38   38
United Kingdom 39 70.8c 110 3.2 113
United States 388 52.5d 440.5 47 487.5
Total (rounded) 1291 231 102.5 1625 156 1780

(a) The figures in this table are central estimates, except for North Korea. Values are rounded.

(b) At the end of 2002, most of North Korea’s plutonium was in spent fuel.

(c) Contains 4.4 tonnes of British excess plutonium.

(d) Contains 4-5 tonnes of separated plutonium produced in U.S. and British power reactors that is included in the civil unirradiated category in Tables 1 and 2 in ‘Separated Civil Plutonium Inventories: Current Status and Future Directions,’ June 10, 2004.

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Table 3: Unirradiated Civil Plutonium Produced in Power Reactor Programs, end 2002, in tonnes

A: Holdings in-country B: Holdings in other countries C: Tonnes of A that are foreign-owned D: Plutonium owned by a country (A+B-C)
Britain 90.8 0.9 20.9 70.8a
France 79.9 less than 0.05 32.0 47.9
Belgium 3.4 0.4 ~2 1.8
Germany 11.1 ~14.5 not declared 25.6
Japan 5.3 33.3 0 38.6
Switzerland 0.8 0-2 0 0.8-2.8
Russia 37.2 0.6 0 37.8
China 0 0 0 0
United States b 0 0 b
India ~1 0 0 1
Netherlands 0 2 0 2
Italy 0? 2.3-2.4 0 2.3-2.4
Sweden 0 0.833 0 0.83
Spain 0.1? 0.1-1 0 0.2-1.1
TOTAL 230 229-233

(a) Of this value, 4.4 tonnes are British excess military plutonium produced in military reactors. Because this amount of plutonium is included in Britain’s INFCIRC/549 declaration, it is included here.

(b) The United States is estimated to have about 4-5 tonnes of unirradiated plutonium that was originally produced in civil reactors. The bulk of this plutonium was produced in British civil reactors and exported to the U.S. military program several decades ago. These 4-5 tonnes are part of the 52.5 tonnes declared excess by the United States and are treated as part of that amount in tables 1 and 2.

Source: For the first nine countries in the table, the main sources of information are the IAEA’s INFCIRC/549 declarations. The estimates for the last five countries depend on a variety of sources of information. The totals of Columns A and D do not match exactly because the declarations are incomplete and several estimates are required to complete the table. For more detailed sourcing, see Table 1, ‘Separated Civil Plutonium Inventories: Current Status and Future Directions,’ June 10, 2004.

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Table 4: Separated Civil Power Reactor Plutonium Inventories and Projected Inventories, in tonnes

  Separated Civil Plutonium Owned by a Country, end of 2002 Separated Civil Plutonium Owned by a Country, 2010
Central estimate or median, (uncertainty range)
Separated Civil Plutonium Owned by a Country, 2015
Central estimate or median, (uncertainty range)
Separated Civil Plutonium Owned by a Country, 2020
Central estimate or median, (uncertainty range)
Countries with firm plans to use civil MOX
45 (40-50)
29 (23-34)
50 (40-60)
42 (35-50)
17 (8-25)
50 (20-80)
38 (25-50)
5 (0-16)
40 (15-80)
Countries without firm plans to use civil MOX through 2020
Britain (includes excess military plutonium)
Countries with plans to dispose of excess military plutonium (U.S. and Russia), see tables 6 and 7
Total (rounded)
230 270 (250-290) 250 (210-300) 230 (190-290)

Source: Table 2, ‘Separated Civil Plutonium Inventories: Current Status and Future Directions,’ June 10, 2004.

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Table 5: Military and Excess Stocks of Plutonium in the Acknowledged Nuclear Weapon States, end of 2003, in tonnes

Official State Declaration of Stocks
Totala Military Stockb Declared Excess Under Safeguards
U.K. 7.6 (2%?) 3.2 4.4 4.4
U.S. 99.5 (2%) 47 52.5 2

ISIS Estimates of Stocks
Totala Military Stockb Declared Excessb Under Safeguards
Chinac 4.8 (3.0-6.8) 4.8 0 0
France 5 (3.6-6.4) 5 0 0
Russiad 145 (120-170) 95 50 0
Total 262 (232-292)e 155 107e 6.4

(a) The values in the parentheses are the percentage uncertainty or the range of the total estimated stock.

(b) Only the central estimates are used in this column.

(c) China’s military plutonium stock remains highly uncertain. It reportedly continued to produce plutonium in at least one military reactor after Chinese officials unofficially acknowledged that plutonium production for weapons ceased in 1991. The estimate for the amount of military plutonium produced prior to this cutoff is 2.0-3.8 tonnes.

(d) Russia continues to produce about 1.4 tonnes/year of plutonium in its three remaining plutonium production reactors. Plutonium produced after late 1994, or almost 13 tonnes, is legally banned from use in nuclear weapons. However, this plutonium is not believed to be included in Russia’s INFCIRC/549 declaration, and thus it is treated as part of Russia’s military stock. Prior to 1994, Russia is estimated to have produced about 130 tonnes of plutonium.

(e) Rounded.

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Table 6: Current and Projected U.S. and Russian Stocks of Excess Unirradiated Plutonium Subject to MOX Disposition, in tonnes*


United States



16 (11-20)
15 (7-22)

6 (0-12)
5 (0-15)

0 (0-5)
0 (0-8)

Notes *The values in parentheses are the range in the estimates. The lower values for 2025 and 2030 are arbitrarily set at zero. Similarly, the central estimates for 2030 are set at zero. In practical terms, the zero values for the central estimates for 2030 mean that all the plutonium will likely have been disposed of by this time.

Source: Table 4, ‘Separated Civil Plutonium Inventories: Current Status and Future Directions,’ June 10, 2004.

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Table 7: Civil Unirradiated Plutonium, from Civil Reactors and Declared Military Excess, in tonnesa

Origin       2003       2010       2015       2020
Civilb       235       270 (250-290)       250 (210-300)       230 (190-290)
US and Russian Excessc       95       95       78 (71-84)       55 (42-66)
Total (rounded)       330       365 (345-385)       330 (280-380)       285 (230-360)

(a) The values in parentheses are the lower and upper bounds of each estimate, derived from the bounds in tables 4 and 6.

(b) This quantity includes British excess military plutonium.

(c) Derived from tables 5 and 6. About 7 tonnes of U.S. excess plutonium are in spent fuel and not included here.

Source: Table 6, ‘Separated Civil Plutonium Inventories: Current Status and Future Directions,’ June 10, 2004.

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