The alpha spectrometer system for Pu analyses included four alpha detectors and the related equipment necessary for counting and data printout or storage. The alpha system was located entirely within the electronics rack. Each alpha unit had a solid state silicon detector that was sensitive to alpha particles when under a vacuum. The actual counting electronics were contained in a nuclear instrument module or NIM Bin, with attached power supply providing the necessary voltage. The alpha pulses were directed through a pre-amplifier and amplifier to shape and increase the output signal for analyses. The pulses were then put into a gated analogue router (GAR) which routed the signal to an analogue digital converter (ADC) for spectrometry. The GAR eliminated the need for four ADC units and thereby directed the appropriate alpha pulses into a selected portion of the PHA memory. Spectrum results were displayed on cathode ray tube (CRT) terminals for manipulation and control. for final data reduction. Information was then printed out through the HP9831 computer printer The gamma spectrometer system for isotopic analyses included three built-in shields to enclose intrinsie germanium (IG) detectors plus their related electronic hardware. Two permanently installed shields were constructed of low-background, two-inch steel plate and placed at one end of the trailer. One shield contained a large-area upright IG coaxial detector referred to as IG~1 and its companion shield was used for the spare IMP planar detectors (IG-2 through IG-7). Both shields were designed to accommodate either uplooking or downlooking detector models. When the FPDB program began in 1979, EIC was authorized to construct a third shield to supplement the laboratory eapabilities for gamma counting. This shield was made of two-inch lead brick and placed by the electronics rack. A planar detector was then transferred to the new shield and an uplooking coaxial detector was installed into the vacant permanent shield. The shields were equipped with plexiglass liners, sample support shelves adjustable to 1 em increments, and had interchangeable circular cutouts and rings to hold the samples for the various counting geometries used. An additional four-inch lead brick shield was also installed to hold a 2 x 2-inch sodium iodide detector for any required gross gamma counting. The IG gamma detector electronics consisted of a pre-amplifier mounted on each individual unit, a high voltage bias supply in the rack, plus two NIM Bins that contained the amplifiers, ADC, and Multiplex (MUX) modules necessary to combine and channel the signals to the PHA. Spectrum results were displayed on CRT terminals and the final data were stored on magnetic tape cartridges in the HP9831 computer. Electronic readouts for the sodium iodide detector were provided through a Single-channel analyzer and scaler also mounted on the electronics rack. The gross alpha and beta counting systems consisted of two standard EIC scintillation alpha counters (SAC-4), and two EIC Model A-23 large-area gas proportional counters. The SAC-4 units measured gross alpha on two-inch filter papers and planchet samples for detecting contamination levels in the RADLAB complex. Both of the large-area alpha and beta counters used chemically pure (CP) grade methane gas for counting. The beta unit also had a two-inch lead shield to reduce background interference from cosmic sources. MS-2 sealers. Electronic readouts for the units were channeled through mini Additional low-level counting of alpha and beta was provided by two other instruments. A Beekman LS-100C Liquid Scintillation Counter was set up to detect gross alpha on nose swipes collected in the FRST personnel monitoring program. However, it was also calibrated to count low energy betas. A low background Canberra 2000 simultaneous alpha-beta counter was set up for beta determinations. The counter electronics consisted of a high voltage power supply, amplifier/timing single-channel analyzers, anticoincidence gate-delay, and manual readout scaler/timers mounted in the rack. The beta unit was a 4n methane gas proportional counter with an 80 pg/em2 window and integral anticoincidence guard. The three-bay electronics rack provided the power sources, NIM Bin mounting and analyzer/processor space for the alpha detectors and gamma electronics modules. Additional electronic equipment included troubleshooting multimeters, sliding pulsers, cable patch panels and other digital instruments. All counters and terminal units in the laboratory were cabled to the electronics rack through an under-floor conduit system. These cables supplied intereonnections for high voltage power supply, preamplified power, signal and data output. Interconnection coaxial cables used for high voltage and signals were RG-59/U and RG-62/U, respectively. 114