Click on the links below to view the Circulars
- 13-01 Ventron Corporation Special Exposure Cohort (SEC) Class from November 1, 1942 through December 31, 1948
- 13-02 Oak Ridge National Laboratory (X-10) Special Exposure Cohort (SEC) Class from June 17, 1943 through July 31, 1955
- 13-03 Los Alamos National Laboratory Special Exposure Cohort (SEC) Class from January 1, 1976 through December 31, 1995
- 13-04 Mound Plant Special Exposure Cohort (SEC) Class from September 1, 1972 through December 31, 1972 or from January 1, 1975 through December 31, 1976
- 13-05 Nuclear Metals, Inc. Special Exposure Cohort (SEC) Class from October 29, 1958 through December 31, 1979
- 13-07 Joslyn Manufacturing and Supply Company Special Exposure Cohort (SEC) Class from March 1, 1943 through December 31, 1947
- 13-08 Baker Brothers Special Exposure Cohort (SEC) Class from June 1, 1943 through December 31, 1944
- 13-09 Battelle Laboratories King Avenue Special Exposure Cohort Class (SEC) from April 16, 1943 through June 30, 1956
- 13-10 Pacific Northwest National Laboratory (PNNL) did not exist separately from Hanford until 2005
- 13-11 No Circular Released