consists of two pods mounted on a helicopter or light aircraft. contains 20 5" x 2" Nal crystals. Each pod The signals from these detectors are summed and submitted to a data acquisition system. The output is monitored py 8 single channel analyzers and a multichannel analyzer for gamma cpectral analysis. whose Also included in the system is an inertial navigation system output is recorded simultaneously with the radiation data on magnetic tape. , : If the system were mounted on a helicopter travelling at 100 ft/sec, the spatial resolution for 241an on the surface is approximately 100 feet _when using the single channel mode of operation. High energy gamma emitters may be located with a spatial resolution of about 50 feet based upon the accuracy of the inertial navigation system. for 600, and 137 Cs The minimum limits of detection is about 1 4R/hr and approximately 1 pCi/me for abla The system may also be flown satisfactorily on small fixed wing aircraft, but the spatial resolution is directly related to airspeed. +o Cosadaa. The total weight of the system is 1400 lbs and requires 3 people to operate. It would take approximately 1-3 weeks to complete the survey de- pending upon meteorological conditions. pr 2, Aerial photographs of the islands may also be taken with a separate EG&G system which incorporates four Hasselblad cameras equipped with 80 mm lenses. High resolution photographs obtained with this system are a necessity in order to accurately identify locations where soil samples and survey meter readings were obtained as well as to assist in assessing the amount of cleanup that will be required. Soil Sampling Program The soil sampling program of the survey will be conducted in a manner that will insure statistically meaningful results. samples will be collected for analysis: 15 em deep cores of 30 ome area each; (2) (1) Several types of soil A sample consisting of two A surface soil sample collected by a "cookie cutter” of 30 em? area to a depth of 5.0 cm; and (3) A profile collection based upon side wall sampling in a trench in which complete samples of fixed horizontal area are taken to selected depths. enmeninon materialePACER. ons The increments of depth are chosen according to predicted, suspected, . or known radioisotope concentration vs. depth relationships and also according to any soil horizons present at the sample location. » Nominal (arte