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Title: Evaluation of polyacrylonitrile (PAN) as a binding polymer for absorbers used to treat liquid radioactive wastes

Evaluation of polyacrylonitrile (PAN) as a binding polymer for absorbers used to treat liquid radioactive wastes The chemical and radiation stability of polyacrylonitrile (PAN) in the form of beads (B-PAN), similar to the beads of composite absorbers, and one selected composite absorber (ammonium molybdophosphate, the active component in PAN binder [AMP-PAN], a prospective candidate for the treatment of acidic wastes) were studied. Aqueous 1M HNO{sub 3} + 1M NaNO{sub 3}, 1M NaOH + 1M NaNO{sub 3}, and 1M NaOH were chosen as simulants of DOE acidic and alkaline wastes. In addition,radiation stability was determined indistilled water. The chemical stability of B-PAN and AMP-PAN beads was tested for a period up to one month of contact with the solution at ambient temperature. The radiation stability of the beads was checked in a radiation dose range 10{sup 3}--10{sup 6} Gy (10{sup 5}--10{sup 8} rads). In acidic solutions the stability of PAN binder was proved not to be limited by either chemical or radiation decomposition. PAN binder may thus be used for preparing composite absorbers for treatment of acid wastes from DOE facilities. The same conclusion is valid for alkaline solutions with pH up to 13. In highly alkaline solutions (concentration of NAOH higher than I M) and in the presence of NaNO{sub 3}, the stability of the tested more » polyacrylonitrile polymer was sufficient for applications not extending over 10 days. Cross-linking of the polymer caused by ionizing radiation was found to have a positive influence on chemical stability. This effect enables a longer period of applicability of PAN-based composite absorbers. Because of the high sorption rate achievable with PAN-based absorbers, the stability achieved is sufficient for most applications in the DOE complex. The chemical stability of binding polymer may also be further improved by testing another, more suitable type of polymer from the broad family of polyacrylonitrile polymers. « less
Authors: ; ; ;
Publication Date:
OSTI Identifier:168591
Report Number(s):SAND--95-2729
ON: DE96004122; TRN: 96:003198
DOE Contract Number:AC04-94AL85000
Resource Type:Technical Report
Data Type:
Resource Relation:Other Information: PBD: Nov 1995
Research Org:Sandia National Labs., Albuquerque, NM (United States)
Sponsoring Org:USDOE, Washington, DC (United States);Florida State Univ., Tallahassee, FL (United States)
Country of Publication:United States