The Consequences of the Shipment of 59 Kilograms of German Plutonium Oxide (PuO2)
The average Pu content of the PuO2, at 30,000 MWd/tonne is 71% fissile plutonium (Pu-239+Pu241) for PWR fuel and 87% fissile plutonium for BWR fuel. In the shipment PWR fuel dominates. The percentage content of Pu isotopes in Pu produced in a PWR at a burn-up of 30,000 MWd/tonne is: Pu-238, 1.3%; Pu-239, 56.6%; Pu-240, 23.2%; Pu-241,13.9%; and Pu-242, 4.7%.
Therefore, 1 milligram (mg) of this Pu will contain 13 micrograms (ug) of Pu-238; 566 ug of Pu-239; 232 ug of Pu-240; 139 ug of Pu-241; and 47 ug of Pu-242.
After storage for 10 years, 1 mg of this Pu will contain 13 micrograms (ug) of Pu-238; 566 ug of Pu-239; 232 ug of Pu-240; 80 ug of Pu-241; 59 ug of Am-241; and 47 ug of Pu-242.
The relevant specific activities in Bq/ug are:
| Pu-238 | Pu-239 | Pu-240 | Pu-241 | Pu-242 | Am-241 | |
| Half-life (in years) | 87.74 | 24,110 | 6,537 | 14.4 | 376,000 | 432.2 |
| Spec activity | 634,889 | 2,301 | 8,451 | 3,820,270 | 145.7 | 127,283 |
The specific activity of 1 mg is, therefore, 13 x 634,889 + 566 x 2,301 + 232 x 8,451 + 80 x 3,820,270 + 47 x 145.7 + 59 x 127,283 = 325 million Bq per mg = 325,000 million Bq per gram = 325 million million Bq per kilogram = 325 Tq per kilogram = 20,000 Tq per 59 kilograms.
Note: If the fuel were fresh (no Am-241), the specific activity would be 540 TBq/kilogram, or 32,000 TBq per 59 kilograms.
The NCI figure of a limit of 1 metric tonne (= 1,000 kilograms) of fresh reactor-grade Pu implies a limit of 540,000 TBq.
The IMO limit, according to NCI figures, is clearly absurdly and irresponsibly high, set for economic and commercial reasons rather than safety and security ones. For 10-year old reactor-grade fuel, it would allow the transport of 1,660 kilograms, or 1.66 metric tonnes. This is equivalent to more than 400 nuclear weapons, about equal to the British or French nuclear arsenals. The 59 kilograms in the shipment would make about 15 nuclear weapons.
The IMO limit should also be compared with the health risks if Pu gets into the human environment. The inhalation and ingestion toxicities (for fatal cancers) of PWR reactor-grade Pu at 30,000 MWd/tonne are:
| INHALATION | INGESTION | ||
| cancers/mg | mg/cancer | cancers/mg | mg/cancer |
| 13.73 | 0.073 | 0.264 | 3.80 |
If a population inhales a total of 1 gram of Pu, about 14,000 fatal cancers will occur. The ingestion of 1 gram of Pu will produce about 260 fatal cancers.