Canadian Nuclear Safety Commission
Draft for Public Consultation
Table 8-2: Subcritical Limits for Single Units of Homogeneously Mixed Oxides of Plutonium and Natural Uranium at Low Moderation [ANSI/ANS 8-12]
(Note: The limits apply to combinations of plutonium isotopes provided 240Pu > 241Pu.)
| Subcritical Limits | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PuO2 in (PuO2 + UO2), wt% | 3 | 8 | 15 | 30 | ||||||||
| Mass of Plutonium, kg | Mass of (PuO2 + UO2), kg | Mass of Plutonium, kg | Mass of (PuO2 + UO2), kg | Mass of Plutonium, kg | Mass of (PuO2 + UO2), kg | Mass of Plutonium, kg | Mass of (PuO2 + UO2), kg | |||||
Dry mixed oxides at theoretical density Density of (PuO2 + UO2) ≤ 11 g/cm3 H : (Pu + U) = 0 |
Subcritical in any amount | 122 | 1729 | 47.0 | 355 | 26.1 | 98.6 | |||||
Damp mixed oxides at theoretical density Density of (PuO2 + UO2) ≤ 9.4 g/cm3 0 < H : (Pu + U) ≤ 0.45 |
236 | 8919 | 49.4 | 700 | 32.9 | 249 | 23.3 | 88.1 | ||||
Damp mixed oxides with 50% voids Density of (PuO2 + UO2) ≤ 4.7 g/cm3 0 < H : (Pu + U) ≤ 0.45 |
885 | 33,447 | 161 | 2282 | 102 | 771 | 67.9 | 256.6 | ||||
