Ill. Admin. Code tit. 35 § 1010.200
Within 24 hours after an unpermitted release of a radionuclide from a nuclear power plant into groundwater, surface water, or soil, the licensee must evaluate the release in compliance with this Section to determine whether it must be reported. The evaluation must be based on the volumes of station-generated liquids and concentrations or quantities of radionuclides released, not on the volumes of station-generated liquids and concentrations or quantities of radionuclides remaining after the initiation or completion of response actions. The licensee must report the release in compliance with Section 1010.202 if the unpermitted release of station-generated liquids either results in tritium concentrations of 200 pCi/L or more outside the licensee-controlled area or contains tritium at quantities of 0.002 curies or more.
Ill. Admin. Code tit. 35, § 1010.200