[en] In the mouse the gastrointestinal absorption of hexavalent plutonium (the form present in chlorinated drinking water) is (1) a factor of about ten lower in the fed animal than in the fasted one (0.015 vs 0.15%), (2) independent of plutonium concentration over a range that broadly brackets the MPC for plutonium in drinking water, and (3) independent of the time of day the solution is administered to fasted animals. Other factors related to the determination of G.I. absorption which have been investigated are: (1) the adsorption of plutonium onto teeth of animals during both gavage and ad libitum administrations, (2) the formation of polymeric tetravalent plutonium during and subsequent to solution preparation, and (3) the relationship between the metabolic behavior of plutonium solutions, administered both intragastrically and intravenously, and their ultrafilterability

[en] Analyses are presented of the ratios of ₂₂₆Ra to calcium in over 650 samples of compact and cancellous bone from 66 female and 26 male subjects who had died from less than one to 60 years after first exposure to radium. The ₂₂₆Ra/Ca ratios were normalized to the terminal ₂₂₆Ra skeletal content. The ₂₂₆Ra/Ca ratios for vertebrae were essentialy identical to those for other cancellous bone for a given subject. Comparisons of the data with predictions of the ICRP model of alkaline earth metabolism show that for female cancellous bone the normalized ₂₂₆Ra/Ca ratios tended to be greater than predicted, while those for female cortical bone (femoral and tibial shaft) tended to be less. The data for males were fitted better by the model. A modification of the model to reduce the amount of radium deposited in soft tissue fitted the data better in some respects. A straight line linear least squares fit to the data appeared to fit as well as, or better than, the models. A radiation effect was suggested in that the normalized ₂₂₆Ra/Ca ratio for vertebrae relative to the ratio expected increased with skeletal absorbed dose for vertebra. However, no such effect was apparent for compact bone or for the cancellous bone as a whole

[en] An Analytical Measurements Information Database Application was developed to give an overall view of the criteria involved in the selection of an analytical measurement technique. This specific database application was developed for the measurement of elemental concentration of uranium. It includes information on many components of each measurement technique and allows easy comparison of different techniques. The integrated data information for the methods contained in this program include the specific technique, expected precision and bias, materials applicability, interferences, analysis time, reagents needed, training time, instrumentation required and its associated costs, and resulting process streams. Process stream information may be used to determine the method of preference based on pollution prevention opportunities. Use of this information also serves as an up-front indication of the types of waste generated when different analytical methods are implemented. Most sites, through pollution prevention programs and departmental mandates, are required to generate annual waste forecasts. The use of the process stream information greatly reduces the difficulty of predicting waste generation rates for different analytical methods, while the accuracy of such predictions is substantially increased

[en] In mice that are consuming food ad libitum the gastrointestinal absorption of plutonium (and its subsequent retention in liver and skeleton) has been shown to be a factor of about 10 lower than it is in the fasted anaimal. It has been found that the time required to achieve the fasted state is less than two hours for mice that are at the end of their diurnal, inactive phase and between 4 and 8 hours for mice that are 4 hours into their active phase. The absorption of plutonium appears to depend on the nature of materials in the G.I. tract, i.e., properties of the food consumed, rather than amounts present. The fractional absorption of plutonium from the G.I. tract by the rat decreases with age in the unweaned animal, from 7 x 10^-₃ on day 1 to 3 x 10^-₃ on day 19 (the latter value being the same as that for the fasted adult) and with weaning to 1 x 10^-₄ on day 29

No abstract available

[en] The fraction of plutonium absorbed after oral administration of Pu(VI) to 24-h-fasted mice was 19 X 10(-4), 13-fold higher than in fed mice, 1.4 X 10(-4). We have investigated the relevance of the high gastrointestinal (GI) absorption value for the 24-h-fasted animals in setting drinking water standards for humans. When fasting was initiated at the beginning of the active phase of the mouse's daily activity cycle (when they would normally eat), plutonium GI absorption rose from 2.8 X 10(-4) at zero-time to a level typical of the 24-h-fasted mouse after only 2 h of fasting. In contrast, in mice allowed to eat for 4 h into their active phase prior to initiation of the fast (meal-fed mice), 8 h of fasting were required before GI absorption rose to a level similar to that of the 24-h-fasted mouse. The fraction of plutonium retained after gavage administration of Pu(VI) to 1-day-old rats was 74 X 10(-4), 70-fold higher than the value for fed adults. Retention after GI absorption in neonates remained 30- to 70-fold higher than in adults until weaning. One week after weaning, the fraction absorbed and retained by fed weanling rats was the same as that for fed adults, 1 X 10(-4). Drinking water standards for plutonium have been set based on GI absorption values for fed adult animals. The 10- to 100-fold increases in plutonium absorption in young and fasted animals reported by ourselves and others, and the rapid rise to fasted levels of absorption at the start of the animal's active phase, indicate that consideration should be given to elevated levels of plutonium absorption in young and fasted individuals

[en] The gastrointestinal (GI) absorption of plutonium was measured in mice, rats, and dogs under conditions relevant to setting drinking water standards. The fractional GI absorption of Pu(VI) in adult mice was 2 x 10^-4 (0.02%) in fed mice and 2 x 10^-3 (0.2%) in fasted mice. The GI absorption of plutonium was independent of plutonium oxidation state, administration medium, and plutonium concentration; absorption was dependent upon animal species, state of animal fasting, state of Pu(IV) hydrolysis, and age of the animal. Fractional GI absorption values ranged from 3 x 10^-5 (0.003%) for hydrolyzed Pu(IV) administered to fed adult mice to 7 x 10^-3 (0.7%) for Pu(VI) administered to fed neonatal rats. From analysis of our data, we suggested values of f₁ (the fraction transferred from gut to blood in humans) for use in establishment of oral limits of exposure to plutonium. For an acute exposure in the occupational setting, we proposed one value of f₁ for fed (2 x 10^-4) and one for fasted (2 x 10^-3) individuals. For the environmental setting, we developed two approaches to obtaining values of f₁; suggested values were 6 x 10^-4 and 4 x 10^-3, respectively. Both approaches took into account effects of animal age and fasting. We discussed uncertainties in proposed values of f₁ and made recommendations for further research. 41 refs., 8 figs., 24 tabs

[en] The method of plutonium (Pu) determination at the Brunswick Laboratory (NBL) consists of a combination of ion-exchange purification followed by controlled-potential coulometric analysis (IE/CPC). The present report's purpose is to quantify any detectable Pu loss occurring in the ion-exchange (IE) purification step which would cause a negative bias in the NBL method for Pu analysis. The magnitude of any such loss would be contained within the reproducibility (0.05%) of the IE/CPC method which utilizes a state-of-the-art autocoulometer developed at NBL. When the NBL IE/CPC method is used for Pu analysis, any loss in ion-exchange purification (<0.05%) is confounded with the repeatability of the ion-exchange and the precision of the CPC analysis technique (<0.05%). Consequently, to detect a bias in the IE/CPC method due to the IE alone using the IE/CPC method itself requires that many randomized analyses on a single material be performed over time and that statistical analysis of the data be performed. The initial approach described in this report to quantify any IE loss was an independent method, Isotope Dilution Mass Spectrometry; however, the number of analyses performed was insufficient to assign a statistically significant value to the IE loss (<0.02% of 10 mg samples of Pu). The second method used for quantifying any IE loss of Pu was multiple ion exchanges of the same Pu aliquant; the small number of analyses possible per individual IE together with the column-to-column variability over multiple ion exchanges prevented statistical detection of any loss of <0.05%. 12 refs

[en] New Brunswick Laboratory (NBL), the US government's nuclear materials measurements and reference materials laboratory, administers interlaboratory measurement evaluation programs to evaluate the quality and adequacy of safeguards measurements. The NBL Measurement Evaluation Program covers several types of safeguards analytical measurements. The Safeguards Measurement Evaluation (SME) program distributes test materials destructive measurements of uranium for both elemental concentration and isotopic abundances, and of plutonium for isotopic abundances. The Calorimetry Exchange (CalEx) Program tests the quality of nondestructive measurements of plutonium isotopic abundances by gamma spectroscopy and plutonium concentration by calorimetry. In May 1997, more than 30 representatives from the Department of Energy (DOE), its contractor laboratories, and Nuclear Regulatory Commission licensees met at NBL in Argonne, Illinois, for the annual meeting of the Measurement Evaluation Program. The summary which follows details key points that were discussed or presented at the meeting

[en] This project studies the gastrointestinal absorption of plutonium and other actinide elements relevant to nuclear power production, at concentrations at or below their respective maximum permissible concentrations (MPC's) in drinking water, using high specific activity isotopes. The gastrointestinal absorption of plutonium is measured in mice, rats, and dogs exposed to plutonium either via drinking water or by gavage. Plutonium concentrations are determined in liver and eviscerated carcass at 6 days (mice and rats) or 4 weeks (dogs). Administered solutions are 1 x 10^-10 M in Pu (the molar concentration at MPC for ²³⁹Pu) and contain one of several high specific activity isotopes (²³⁷Pu, 47-day half-life; ²³⁶Pu, 2.8-year half-life; ²³⁸Pu, 86-year half-life). Fasted mice and rats, administered plutonium solutions that are: (1) low in concentration (10-¹⁰M); and (2) carefully prepared to assure a given oxidation state and to avoid hydrolysis and polymes, and major policy issues. The first HEED for near-term battery energy storage systems (lead/acid, nickel/zinc, and nickel/iron) astention being paid to potential releases of radionuclides at relatively short times after disposal