Holdup Measurements of Plutonium in Glove Box Exhausts

Conference · Sun Sep 29 04:00:00 EDT 1991

OSTI ID:5338374

Glick, J. B. ^[1]; Haas, F. X. ^[1]; McKamy, J. N. ^[1]; Garrett, A. G. ^[1]; Russo, P. A. ^[2]; Sheppard, G. A. ^[2]; Miller, M. C. ^[2]

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1. EG and G Rocky Flats, Inc., Golden, CO (United States). Rocky Flats Plant
2. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

A new measurement technique has been developed to quantify plutonium in process glove box exhausts. The technique implemented at Rocky Flats Plant utiltizes a shielded, collimated 0.5in. ˙ 0.5in. bismuth germanate (BGO) gamma-ray detector. Pairs of measurements are made at one foot intervals along the duct. One measurement is made with the detector viewing the bottom of the duct with the detector crystal approximately 2 inches from the duct surface. The second measurement is made on the top of the exhaust pipe with the detector crystal 2 inches from the top of the duct. When the detector is placed in the bottom assay position, the area of the holdup material is assumed to extend beyond the detector field of view. The concentration of plutonium in g/cm² is obtained from this bottom measurement. The deposit width is determined from a model developed to relate the deposit width to the ratio of the count rates measured at the two positions, above and below the duct. Once a deposit width has been calculated, it is multiplied by the concentration determined from the bottom measurement to yield a mass- per-unit-length at the duct location. Total plutonium mass is then determined by multiplying the duct length by the average of the mass- per-unit length assays performed along the duct. The applicability of the technique is presented in a comparison of field measurement data to analysis results on material removed from the ducts.

• Research Organization: EG and G Rocky Flats, Inc., Golden, CO (United States). Rocky Flats Plant; Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• DOE Contract Number: AC34-90DP62349
• OSTI ID: 5338374
• Report Number(s): RFP--4459; CONF-910901--6; ON: DE91018556
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
42 ENGINEERING
420203* -- Engineering-- Handling Equipment & Procedures
440102 -- Radiation Instrumentation-- Radiation Dosemeters
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ACTINIDES
BGO DETECTORS
CALIBRATION
DATA ACQUISITION
DUCTS
ELEMENTS
EQUIPMENT
EXHAUST GASES
FLUIDS
GASEOUS WASTES
GASES
GLOVEBOXES
LABORATORY EQUIPMENT
MEASURING INSTRUMENTS
METALS
MONITORING
Measurement Technique
Measurements
Nuclear Criticality Safety Program (NCSP)
PERFORMANCE TESTING
PLUTONIUM
RADIATION DETECTORS
RADIATION MONITORING
SCINTILLATION COUNTERS
SOLID SCINTILLATION DETECTORS
TESTING
TRANSURANIUM ELEMENTS
WASTES