Faculty and Student Teams Program

Project Descriptions

Pacific Northwest National Laboratory
Radiochemical Science and Engineering Group

Requesting applications from science or engineering faculty members at institutions serving students underrepresented in science, engineering, mathematics, and technology, to work on developing a Raman spectral database for identifying inorganic solid phases present in Hanford radioactive tank waste.

Project Description

Project Title:  Development of Raman Spectral Database for Tank Waste Characterization
Research has been ongoing at the Pacific Northwest National Laboratory to validate and optimize the process flowsheets to be implemented at the Hanford Waste Treatment Plant (WTP).  The WTP is being designed and constructed to immobilize the large volumes of radioactive wastes that are stored in underground tanks at the Hanford Site in southeastern Washington state.  These wastes were generated during past plutonium production and other operations.  In the WTP, the wastes will be partitioned into low-activity and high-level fractions.  Both fractions will be immobilized in borosilicate glass waste forms suitable for final disposition.  The low-activity waste (LAW) fraction will be disposed of by shallow burial onsite, while the high-level waste (HLW) will be disposed of in a geologic repository.

The solid fraction of the Hanford tank waste is classified as HLW.  These HLW solids will be pretreated by a series of leaching and washing steps to reduce the amount of HLW glass produced during the Hanford environmental remediation mission.  Optimizing the HLW pretreatment processes will depend on identifying the key compounds present in the tank waste solids.  Currently, the solids are characterized through a combination of X-ray diffraction and microscopic methods.  The former method is ineffective for amorphous solid phases, and the latter can be somewhat subjective in terms of interpretation.  Raman spectroscopy offers a complementary method for characterizing the HLW solids.  It can be used for both crystalline and amorphous materials and the spectra of individual compounds provide “fingerprints” for those compounds.  Furthermore, the method is readily amenable to measurement of highly radioactive samples.

In this project, Raman spectra will be recorded for a series of compound known to be, or likely to be, present in the Hanford HLW tank solids.  Example compounds to be examined include various metal phosphates, sulfates, carbonates, and oxides/hydroxides.  The spectra obtained will be used to construct a spectral database to be used in characterizing the solid phases present in actual tank waste samples.  The work performed under this project will not involve hands-on work with radioactive materials.  The compounds to be examined are all available in non-radioactive forms.  Radioactive samples may be examined (e.g., uranium compounds), but in those cases PNNL staff will handle the radioactive materials.  Each participant will need to be trained as Radiological Worker I to allow access to Radiological Buffer Areas.

Applicants Responsibilities and Relationship to Project

Applicants will receive support under the Department of Energy Faculty Student Team Research Program (FaST) to work collaboratively with the project research team at the Pacific Northwest National Laboratory for up to 10 weeks during the year, starting in May or June 2008. Summer and academic year visits to PNNL will be scheduled by mutual agreement between the Radiochemical Science and Engineering Group and the successful applicant. Faculty will be expected to identify students from their campus to participate in the Undergraduate Research Participation programs offered by the Department of Energy at Pacific Northwest National Laboratory. Faculty will provide mentorship and/or advising support to students during the summer research activities. It is expected that the faculty member will become an integral part of the research team working on this project and will support the project through the academic year on her or his campus.

Qualifications of Ideal Candidate

Support and Financial Commitments

See Financial Information.

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