Smallest fissile materialAny substance which can be fissioned by neutrons, during whi... mass which under fixed conditions (type of fissile materialAny substance which can be fissioned by neutrons, during whi..., geometry, moderated/immoderate system, etc.) initiates a self-perpetuating chain reactionSelf-perpetuating reaction. In a fission chain reaction, a f.... The table contains the minimum criticalA reactor is critical when due to nuclear fission as many ne... mass for some nuclides under certain conditions.
| IsotopeAtoms of the same atomic number (i.e. the same chemical elem... |
Smallest criticalA reactor is critical when due to nuclear fission as many ne... mass in spherical shape for aqueous solution at optimum moderationProcess during which the kinetic energy of the neutrons is r... |
Smallest criticalA reactor is critical when due to nuclear fission as many ne... mass in spherical shape for metal (fast systems) |
||
|
Unreflected |
Water-reflected |
Unreflected |
Steel- |
|
| U-233 |
1.080 |
0.568 |
15.8 |
6.1 |
| U-235 |
1.420 |
0.784 |
46.7 |
16.8 |
| Np-237 |
– |
– |
63.6 |
38.6 |
| Pu-238 |
– |
– |
9.5 |
4.7 |
| Pu-239 |
0.877 |
0.494 |
10.0 |
4.5 |
| Pu-240 |
– |
– |
35.7 |
19.8 |
| Pu-241 |
0.511 |
0.246 |
12.3 |
5.1 |
| Am-241 |
– |
– |
57.6 |
33.8 |
| Am-242 |
0.042 |
0.020 |
8.8 |
3.0 |
| Cm-243 |
0.280 |
0.127 |
8.4 |
3.1 |
| Cm-244 |
–
|
–
|
26.6 |
13.2 |
|
Cm-245 |
0.116 |
0.054 |
9.1 |
3.5 |
| Cm-247 |
4.060 |
2.180 |
6.9 |
2.8 |
| Cf-249 |
0.129 |
0.060 |
5.9 |
2.4 |
| Cf-251 |
0.048 |
0.025 |
5.5 |
2.3 |
Smallest criticalA reactor is critical when due to nuclear fission as many ne... masses for some fissile materialAny substance which can be fissioned by neutrons, during whi... under certain boundary conditions