-3- Two of the largest northern islands (Enjebi and Bokambako) were used for this study because of their higher soil radionuclide concentrations and the potential use of Enjebi as a residence and agricultural island. Comparative beta and gamma dose measurements were made at a total of 87 locations on these two islands with thermoluminescent dosimeters, pressurized ionization chambers, portable sodium iodide detectors, and pancake GM probes. Locations were carefully selected to represent a wide range of exposure rates and variety of ground cover. Measurement Methods A portable instrument with a 2.5 cm diameter x 3.8 cm Nal crystal and ratemeter readout was used primarily for selection of measurement location. External exposure rate measurements were made at a height of 1 meter at 67 locations with a pressurized ionization chamber which consists of a stainless steel sphere filled with high pressure argon, connected to an electrometer with digital readout. Calibration of this instrument was verified by DOE laboratories prior to the survey. Although insensitive to beta or low energy gamma radiation, it is sensitive to cosmic radiation. It has a relatively flat energy response over the gamma ray energy range encountered in this survey (NA75). The primary technique used to determine beta or low energy gamma contribution to the external dose rate was measurements made with thermoluminescent (TLD) dosimeters. LiF(TLD 700) previously matched to within +2% were used. The dosimeters were annealed at Enewetak Atoll immediately prior to placement on the two islands. Three TLD dosimeters were placed in the Lawrence Livermore National Laboratory (LLNL) personnel dosimeter badge with a blank badge 9004293