Passive Neutron Non-Destructive Assay for Remediation of Radiological Waste at Hanford Burial Grounds- 13189

Conference · Mon Jul 01 00:00:00 EDT 2013

OSTI ID:22224953

Simpson, A.; Pitts, M. ^[1]; Ludowise, J. D.; Valentinelli, P. ^[2]; Grando, C. J. ^[3]; Haggard, D. L. ^[4]

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1. Pajarito Scientific Corporation, 2976 Rodeo Park Drive East, Santa Fe, NM 87505 (United States)
2. Washington Closure Hanford, 2620 Fermi Ave., Richland, WA 99354 (United States)
3. ELR Consulting, Inc., 15247 Wilbur Rd., La Conner, WA 98257 (United States)
4. WorleyParsons Polestar, 601 Williams Blvd., Richland, WA 99354 (United States)

The Hanford burial grounds contains a broad spectrum of low activity radioactive wastes, transuranic (TRU) wastes, and hazardous wastes including fission products, byproduct material (thorium and uranium), plutonium and laboratory chemicals. A passive neutron non-destructive assay technique has been developed for characterization of shielded concreted drums exhumed from the burial grounds. This method facilitates the separation of low activity radiological waste containers from TRU waste containers exhumed from the burial grounds. Two identical total neutron counting systems have been deployed, each consisting of He-3 detectors surrounded by a polyethylene moderator. The counts are processed through a statistical filter that removes outliers in order to suppress cosmic spallation events and electronic noise. Upon completion of processing, a 'GO / NO GO' signal is provided to the operator based on a threshold level equivalent to 0.5 grams of weapons grade plutonium in the container being evaluated. This approach allows instantaneous decisions to be made on how to proceed with the waste. The counting systems have been set up using initial on-site measurements (neutron emitting standards loaded into surrogate waste containers) combined with Monte Carlo modeling techniques. The benefit of this approach is to allow the systems to extend their measurement ranges, in terms of applicable matrix types and container sizes, with minimal interruption to the operations at the burial grounds. (authors)

• Research Organization: WM Symposia, 1628 E. Southern Avenue, Suite 9-332, Tempe, AZ 85282 (United States)
• OSTI ID: 22224953
• Report Number(s): INIS-US-13-WM-13189; TRN: US14V0396045908
• Resource Relation: Conference: WM2013: Waste Management Conference: International collaboration and continuous improvement, Phoenix, AZ (United States), 24-28 Feb 2013; Other Information: Country of input: France; 4 refs.
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ALPHA-BEARING WASTES
CONTAINERS
ELECTRIC GROUNDS
FILTERS
FISSION PRODUCTS
MATRICES
MODERATORS
MONTE CARLO METHOD
NEUTRONS
NITRIC OXIDE
NOISE
NONDESTRUCTIVE TESTING
PLUTONIUM
POLYETHYLENES
PROCESSING
REMEDIAL ACTION
SIGNALS
SIMULATION
SPALLATION
URANIUM