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Title: Neutron and Gamma Probe Application to Hanford Tank 241-SY-101

A neutron (moisture-sensitive) and gamma (in-situ radiation) probe technique has been utilized at a number of Hanford radioactive waste tanks for many years. This technology has been adapted for use in tank 241-SY-101's two Multifunction Instrument Trees (MITs) which have a hollow dry-well center opening two inches (51 cm) in diameter. These probes provide scans starting within a few inches of the tank bottom and traversing up through the top of the tank revealing a variety of waste features as a function of tank elevation. These features have been correlated with void fraction data obtained independently from two other devices, the Retained Gas Sampler (RGS) and the Void Fraction Instrument (VFI). The MIT probes offer the advantage of nearly continuous count-rate versus elevation scans and they can be operated significantly more often and at lower cost than temperature probes or the RGS or VFI devices while providing better depth resolution. The waste level in tank 241-SY-101 had been rising at higher rates than expected during 1998 and early 1999 indicating an increasing amount of trapped gas in the waste. The use of the MIT probes has assisted in evaluating changes in crust thickness and level and also in estimating relativemore » changes in gas stored in the crust. This information is important in assuring that the tank remains in a safe configuration and will support safe waste transfer when those operations take place.« less
Authors:
Publication Date:
OSTI Identifier:
801314
Report Number(s):
HNF-4897-FP, Rev.0
TRN: US0300397
DOE Contract Number:
AC06-96RL13200
Resource Type:
Conference
Resource Relation:
Conference: Conference title not supplied, Conference location not supplied, Conference dates not supplied; Other Information: PBD: 1 Feb 2000
Research Org:
COGEMA (US)
Sponsoring Org:
ENVIRONMENTAL MANAGEMENT (US)
Country of Publication:
United States
Language:
English
Subject:
12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; CONFIGURATION; NEUTRONS; OPENINGS; PROBES; RADIOACTIVE WASTES; RESOLUTION; SAMPLERS; TANKS; THICKNESS; TREES; VOID FRACTION; WASTES