The cleanup of high level defense nuclear waste at the Hanford site presents several progressive challenges. Among these istheremoval and disposal ofvarious components from buried active wtetikto allow newequipment insetiion orh-ds mitigation. Aunique automated retrieval system at the tank provides for retrieval, high pressure washing, inventory measurement, and containment fordisposal. Keytothe inventory measurement isathree detector HPOehigh performance gamma spectroscopy system capable of

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... overing data at up to ninety per cent saturation(200,000 counts per second). Datarecovery is bssedon aunique embedded electronic pulserand specialized sotkvaret oreportt heinventory. Each of thedetectors have different shielding specified through Monte Carlo simulation tiththe MC~progmm, This shielding provides pefiommce overadynamic range ofeight orders of magnitude. System description, calibration issues and operational experiences are discussed,