| from the plant site | 6 | location |
| from a storage container | 2 | location |
| in 1957 | 2 | temporal |
| plutonium → be → released | 15 |
| plutonium → be released into → the atmosphere | 3 |
| negative | neutral | positive |
| 0.451 | 0.518 | 0.030 |
| Raw frequency | 18 |
| Normalized frequency | 0.637 |
| Modifier score | 0.450 |
| Perplexity | 245.680 |