Assay of long-lived radionuclides in low-level wastes from power reactors

Cline, J.E.; Noyce, J. R.; Coe, L.J.; Wright, Kai

doi:10.2172/5926846

Cited by 9 publications

(12 citation statements)

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“…These forms are the most common species found in the natural environment and typical wastes (e.g., spent ion exchange resins from reactor water demineralizers and reactor com--ponents) fiom power reactors. For details, the reader is referred to Dayal and Reardon (1992), Jefferies (1990), Gruhlke et al (1986, Kunz (1985), Martin (1986), Cline et al (1985), and Impel1 Corporation (1985). Research facility and pharmaceutical wastes may contain organic forms of 14C, but it would be impossible to generalize on the adsorption potential of diverse organic molecules onto cement and concrete.…”

Section: Inorganic Carbon (14c)mentioning

confidence: 99%

Effects on radionuclide concentrations by cement/ground-water interactions in support of performance assessment of low-level radioactive waste disposal facilities

Krupka¹,

Serne²

1998

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C o p k r o f h b r t r y~m d r t n d v d r u n d h 8~m m r h t h . N R C~~r AbstractThe U.S. Nuclear Regulatory Commission (NRC) is developing a technical position document that provides guidance regarding the performance assessment of low-level radioactive waste (LLW) disposal facilities. This guidance includes considerations associated with the chemical environment of the vault disposal system and the effects this system may have on the release and mobility of radionuclides. Because the disposal system will contain cementitious materials as structural, waste form, andor bacld'ill materials, the geochemical properties of pore waters buffered by reactions with cement will be very different from those waters associated with the local soil and geology. This environment therefore needs to be considered within the source term calculations if credit is taken for solubility limits andor distribution coefficients for -dissolved radionuclide concentrqtions within disposal units. Geochemical modeling may be used to assess potential chemical conditions in concrete vault disposal units and associated effects on aqueous speciation, solubilities, and sorption of radionuclides that are released from the waste form.In support of NRC7s development of this technical position, two literature reviews were done on information related to the chemical environments associated with the interaction of water with cementitious materials. One review was conducted on methods and associated solid-phase assemblages used to model the composition of pore water resulting from reaction with cementitious materials used in a disposal vault. This literature review also included related information on experimental studies of cemendwater systems, natural analogue studies of cement and concrete, and radionuclide solubilities experimentally determined in cement pore fluids.Based on the results of .this review, geochemical modeling was used to demonstrate the calculation of conservative maximum concentrations for dissolved americium, neptunium, nickel, plutonium, radium, strontium, thorium, and uranium with respect to key geochemical input parameters for two ground-water environments associated with the disposal system. These environments include 1) a cement buffered system, wherein the leachate pH is controlled at values above 10 by the effective buffering capacity of the concrete; and 2) a ground-water buffered system, wherein the leachate pH and related solution parameters are dominated by the local ground-water system.Another literature review was completed on the available data for the sorption potential of selected LLW radionuclides onto "fresh" cement/concretewhere the expected pH of the cement pore waters will equal or exceed 10. The review included data for the radionuclides americium, inorganic carbon, chlorine, iodine, lanthanide elements, niobium, nickel, neptunium, plutonium, radium, strontium, technetium, thorium, and uranium. Based on information gleaned from the literature, a database was developed of preferred minimum distribution coeff...

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Section: Inorganic Carbon (14c)mentioning

confidence: 99%

Effects on radionuclide concentrations by cement/ground-water interactions in support of performance assessment of low-level radioactive waste disposal facilities

Krupka¹,

Serne²

1998

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“…Correlation evaluation factor uses the statistical technique of weighted least square fits to an assumed linear relation between the logarithmic measured concentrations of alphaemitting radionuclides and the gross alpha activity [5,6]. This means that the function, which on a linear scale, is expressed as…”

Section: Correlation Evaluation Techniquesmentioning

confidence: 99%

Transuranic elements determination in spanish NPP-wastes on the basis of gross alpha activity

Rodrı́guez¹,

Gascón²

2002

Radiochimica Acta

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The characterisation of alpha-emitting nuclides in low and medium level radioactive waste from Spanish nuclear power reactors leads to several difficulties because they cannot be assayed by non-destructive methods due to their low concentration. Thus, long and complex radiochemical procedures are required.In this paper an alternative method for establishing a sufficiently accurate and reliable inventory of long-lived alpha emitting nuclides, is described. The method is based on the application of the factors obtained by correlating the gross alpha activity and the concentration of 238 Pu, 239/40 Pu, 241 Am, 242 Cm and 244 Cm in a set of samples of concentrates and resins from Spanish NPP's.Several statistical tests are performed to evaluate the validity of the assumed relationship and the quality of the correlation. Also, uncertainties are calculated for the parameters of the linear equation relating the concentrations. This work has been performed in the framework of the CIEMAT-ENRESA Association Agreement.

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“…The barium sulfate precipitate is separated from the liquid, dissolved, and liquid-liquid extractions are performed, thus separating the radionuclides into three gr0ups:t.J with Th, Pu with Np, and Am with Cm. Each fraction is electroplated and analyzedusing a surface barrier alpha-particle detector (Cline et al 1985).…”

Section: Americium-curiummentioning

confidence: 99%

“…Oxidizing distillation techniques are employed for liquid or solid samples, which convert greater than 97% of all carbon species to carbon dioxide. The CO, is absorbed in a liquid scintillation cocktail and analyzed for I4C content by liquid scintillation beta counting (Cline et al 1985).…”

Section: Carbon-14mentioning

confidence: 99%

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Radioanalytical technology for 10 CFR Part 61 and other selected radionuclides: Literature review

Thomas¹,

Thomas²,

Robertson³

1996

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NRC Job Code LlSOSDisclaimer is not a substitute for NRC regulations and compliance is not required.The approaches and/or methods described in this NUREGKR are provided for information only.Publication of this report does not necessarily constitute NRC approval or agreement with the information contained herein. AbstractA.comprehensive l i t e r a t u r e review and assessment was conducted t o identify and evaluate radioanalyti cal techno1 ogy and procedures used for measuring 10CFR61 radionuclides and 'other long-1 ived isotopes. This review evaluated radiochemical procedures currently i n use a t a number of laboratories i n the US, as well as identifying new advanced methods and techniques which-could be adapted for routine radiochemical analyses of low-level radioactive waste. The 10CFR61 radi onucl ides i ncl.ude I4C, 6oCo, 59*63Ni , "Sr, 94Nb, "Tc, '''I, 137Cs, and TRU Isotopes w i t h half-lives greater than five years. The other low-level which may be present i n various types of waste streams from nuclear power stations. radi onucl ides of interest i ncl ude 7-'0Be, 26A1 , 36Cl , 9 3 M~, lw.ll%d, and 121a-126 Sn , 0 ... -.

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Assay of long-lived radionuclides in low-level wastes from power reactors

Cited by 9 publications

References 0 publications

Effects on radionuclide concentrations by cement/ground-water interactions in support of performance assessment of low-level radioactive waste disposal facilities

Effects on radionuclide concentrations by cement/ground-water interactions in support of performance assessment of low-level radioactive waste disposal facilities

Transuranic elements determination in spanish NPP-wastes on the basis of gross alpha activity

Radioanalytical technology for 10 CFR Part 61 and other selected radionuclides: Literature review

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