The Science and Technology Agency reported to the Nuclear Safety Commission of the Prime Minister's Office on Jan. 31, 2000 that all together 439 people were either found or estimated to have been exposed to radiation from the JCO accident on Sep. 30, 1999. The break down is as follows.
| Description of the exposed people |
number |
Max. exposure in mSv
except for the three severely exposed ones |
| JCO employees at the site of the accident |
3 |
A |
16 - 20 (gray-equivalent) |
| B |
6.0 - 10 (gray-equivalent) |
| C |
1 - 4.5 (gray-equivalent) |
| Employees at the plant (measured) |
49 |
over 45 - under 50 |
| JCO employees at the plant (estimated) |
96 |
over 15 - under 20 |
| Task force members for stopping criticality (measured) |
24 |
over 45 - under 50 |
| Accident response task force members who were not JCO employees (measured) |
60 |
over 5 - under 10 |
| Residents near-by the plant (measured) |
7 |
over 15 - under 20 |
| Local residents (estimated) |
200 |
over 20 - under 25 |
| TOTAL |
439 |
