| Answer | Crossword Clue |
|---|---|
| ATOMICAL | Fissionable. |
| NUCLEI | Fissionable material |
| ATOM | Fissionable item |
| ATOM | Fissionable particle |
| ATOM | Fissionable unit |
| ATOM | Fissionable unit. |
| ATOMS | Fissionable material |
| PLUTONIUM | Fissionable element. |
| URANIUM | Fissionable material |
| ATOM | Fissionable particle. |
| URANIUM | Valuable fissionable element. |
| URANITE | Product of a fissionable element. |
| URANITE | Chief ore of a fissionable element |
