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

Abstract

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, inmore » terms of applicable matrix types and container sizes, with minimal interruption to the operations at the burial grounds. (authors)« less

Authors:
;  [1]; ;  [2];  [3];  [4]
  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)
Publication Date:
Research Org.:
WM Symposia, 1628 E. Southern Avenue, Suite 9-332, Tempe, AZ 85282 (United States)
OSTI Identifier:
22224953
Report Number(s):
INIS-US-13-WM-13189
TRN: US14V0396045908
Resource Type:
Conference
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
Subject:
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

Citation Formats

Simpson, A., Pitts, M., Ludowise, J.D., Valentinelli, P., Grando, C.J., and Haggard, D.L. Passive Neutron Non-Destructive Assay for Remediation of Radiological Waste at Hanford Burial Grounds- 13189. United States: N. p., 2013. Web.
Simpson, A., Pitts, M., Ludowise, J.D., Valentinelli, P., Grando, C.J., & Haggard, D.L. Passive Neutron Non-Destructive Assay for Remediation of Radiological Waste at Hanford Burial Grounds- 13189. United States.
Simpson, A., Pitts, M., Ludowise, J.D., Valentinelli, P., Grando, C.J., and Haggard, D.L. 2013. "Passive Neutron Non-Destructive Assay for Remediation of Radiological Waste at Hanford Burial Grounds- 13189". United States. doi:.
@article{osti_22224953,
title = {Passive Neutron Non-Destructive Assay for Remediation of Radiological Waste at Hanford Burial Grounds- 13189},
author = {Simpson, A. and Pitts, M. and Ludowise, J.D. and Valentinelli, P. and Grando, C.J. and Haggard, D.L.},
abstractNote = {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)},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2013,
month = 7
}

Conference:
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  • Under the U.S. Department of Energy's River Corridor Closure Project, Washington Closure Hanford has completed remediation of more than 10 mixed low-level waste burial grounds in the 100 and 300 Areas of the Hanford Site. The records of decision for the burial grounds required excavation, characterization, and transport of contaminated material to a Resource Conservation and Recovery Act of 1976-compliant hazardous waste landfill. This paper discusses a sample of the anomalous waste found during remediation and provides an overview of the waste excavation activities. The 100 Area burial grounds received plutonium production reactor waste and waste associated with various testmore » programs. Examples of 100 Area anomalies include spent nuclear fuel, elemental mercury, reactor hardware, and the remains of animals used in testing the effects of radionuclides on living organisms. The 300 Area burial grounds received waste from research and development laboratories and fuel manufacturing operations. Of the seven 300 Area burial grounds remediated to date, the most challenging has been the 618-2 Burial Ground. It presented significant challenges because of the potential for airborne alpha contamination and the discovery of plutonium in an isotopically pure form. Anomalies encountered in the 618-2 Burial Ground included a combination safe that contained gram quantities of plutonium, miscellaneous containers of unknown liquids, and numerous types of shielded shipping casks. Information presented in this paper will be an aid to those involved in remediation activities throughout the U.S. Department of Energy complex and at other nuclear waste disposal sites. (authors)« less
  • Two different approaches were applied to characterization modeling of the waste in the 618-10 and 618-11 burial grounds. The results were compared and it was found that the independent approaches validate each other. The 618-10 and 618-11 burial grounds, located on the Hanford site in Washington state, received primarily radioactive laboratory waste in the 1950's and 60's; however, disposal records from burial activities have since been destroyed. North Wind Inc. (NWI) is completing a technology demonstration project, funded by DOE Headquarters to develop methodology for remediation of the vertical pipe units and develop supporting documentation. Washington Closure Hanford (WCH) ismore » developing a design solution for remediation of the 618-10 and 618-11 burial grounds, including the development of a characterization model and estimates of radioactivity and waste volumes present. Each company independently developed their characterization models and radionuclide inventories, using a different methodology; however, the results of each model revealed only a two to five percent difference, which is significant given the complexity of the waste matrices, the high dose rates of the waste when disposed, and relatively high levels of transuranic radionuclides projected. (authors)« less
  • Washington Closure Hanford, LLC, under contract to the U.S. Department of Energy (DOE), Richland Operations Office, is currently conducting deactivation, decontamination, decommissioning, and demolition of excess facilities; placing former production reactors in an interim, safe, and stable condition; and remediating waste sites and burial grounds in support of the closure of the Hanford Site River Corridor. The Hanford Site River Corridor consists of approximately 565 square kilometers (218 square miles) of the Hanford Site along the Columbia River, in the State of Washington. The regulatory framework to achieve the Hanford Site remediation is established in the Hanford Federal Facility Agreementmore » and Consent Order, commonly known as the Tri-Party Agreement, entered into by the DOE, U.S. Environmental Protection Agency Region 10 (EPA), and the Washington State Department of Ecology. This paper describes the significant challenges associated with the planned remediation of the Hanford 618-10 and 618-11 Burial Grounds. It discusses the process used to identify remediation options, and the process and analysis used to determine the preferred remediation methods that will be included in the Project's design solution document. Additionally, this paper discusses the preferred retrieval methods and how they allow flexibility for change in remediation approach and disposal based on conditions encountered in the field and as waste characterization understanding increases during field characterization, pre-retrieval, and retrieval activities. Finally, this paper discusses the challenges in development of a characterization model, given that little or no records were available to start the project. (authors)« less
  • At the Hanford site, in the 1950's and 60's, radioactive waste materials, including Transuranic (TRU) wastes from a number of laboratories were stored in vertical pipe units (VPUs) in what are now the 618-10 and 618-11 burial grounds. Although the current physical condition of the VPUs is unknown, initial R and D studies had shown that in-ground size reduction and stabilization of VPU contents was feasible. This paper describes the R and D work and testing activities to validate the concept of in-ground size reduction and stabilization of VPU contents, and the design and pre-testing of major plant items andmore » augering systems on full size simulated VPUs. The paper also describes the full size prototype equipment which will be used in full size cold testing of simulated VPUs off the Hanford site, to prove the equipment, develop operating procedures, and train operators prior to deployment on site. Safe and effective field remediation, removal and disposal of the VPUs in the 600 area are critical to the success of the River Corridor Closure Contract at the U.S. Department of Energy's Hanford Site. Safe and effective field remediation, removal and disposal of the VPUs in the 600 area are critical to the success of the River Corridor Closure Contract at the U.S. Department of Energy's Hanford Site. (authors)« less
  • CANBERRA has recently supplied Nucleco SpA with a new Passive/Active Neutron Waste Assay System (PANWAS) for use at their waste management facility at Casaccia in Italy. The system complements two existing CANBERRA high-resolution gamma spectrometry waste assay systems. The three waste assay systems have been integrated into a combined facility for the radiological characterization of the waste managed by Nucleco in order to provide the information required to: - Determine the physical inventory of the nuclear material present for Safeguards purposes, - Segregate the waste into different categories, - Allow transportation to and storage in the final repository for themore » waste. This paper describes the main characteristics of the PANWAS, how it is used (in conjunction with the two gamma monitoring systems) to determine the radionuclide inventory of the waste and how the system was calibrated and characterized for use in this application. (authors)« less