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[en] A technique is described for fabricating minature, high-density capsules of curium-244 oxide contained in three concentric jackets of metallic gold (or silver), with the outer surface being free of alpha contamination. The completed capsules are right circular cylinders 0.2500-inch diameter and 0.125-inch tall, with each level of containment soldered (or brazed) closed. A typical capsule would contain approx. 70 mg of 244Cm (5.7 Ci) mixed with 120 mg of gold powder in the form of a cermet wafer clad in three concentric, 0.010-inch thick, liquid tight jackets. This method of fabrication eliminates voids between the jackets and produces a minimum size, maximum density capsule. Cermet densities of 11.5 g/cc were obtained, with an overall density of 17.3 g/cc for the finished capsule
[en] It is desired to recover Cm-244 through Cm-248 from dissolved Mark-18A targets following anion exchange processing to remove the Pu. The Cm will be sent to Oak Ridge National Laboratory (ORNL) for additional R&D. Approximately 5-8 L per quarter of a Mark-18A target will have undergone anion exchange treatment and will contain Cm. A significant portion of this volume of anion exchange raffinate solution is dissolved fission products not desired to be recovered which could be sent to waste. To reduce the amount of material being sent to ORNL, a waste and volume minimization strategy was developed and is described in this report.
[en] Determination results of curium-245 half-life by four different methods are presented: 1) according to the ratios of molar concentrations of isotopes 245Cm/244Cm and alpha-activities of 244Cm/245Cm; 2) according to specific α-activity of curium-245; i) according to the ratios of molar concentrations of isotopes 245Cm/244Cm and formed during their decay 240Pu/241Pu; 4) according to 241Pu accumulation. In all the four methods curium-245 half-life have been determined as to curium-244 half-life the value of which is accepted to equal 18.099+-0.015 years. Final results are calculated using the method of the maximum verisimilitude taking account of non-excluded systematic errors for fiducial probability Pi-0.95. Average-estimated value of half-life, calculated according to the experiment results, equals 8445+-200 years for fiducial probability p=0.05
[en] 244Cm decays by alpha-particle emission with a half-life of 18.11 years. Alpha-particle emission probabilities (Pα) have been measured using sources produced by electrodeposition and a temperature stabilized chamber with implanted silicon detectors. Several spectra, taken at different geometries, have been analyzed to obtain Pα values for the major emissions. The results are: Pα0=0.7663(18), Pα42=0.2334(18), Pα141=0.000205(15) and Pα294=0.000038(5)
[en] This paper augments INFCE/DEP/WG4/52 (Plutonium Recycling in LWRs) by explaining that the build-up of transplutonium isotopes is higher when starting with MOX fuel than that with uranium fuel. Predictions using the ORIGEN computer codes have not been substantiated in practice. Further experiments are therefore necessary
[en] The Curium Source Fabrication Facility (CSFF) at Oak Ridge National Laboratory (ORNL) was decontaminated to acceptable contamination levels for maintenance activities, using standard decontamination techniques. Solid- and liquid-waste volumes were controlled to minimize discharge to the ORNL Waste Systems. This program required two years of decontamination effort at a total cost of $580K
[en] The spectrum of curium-244 has been observed on the high resolution Fourier-transform spectrometer at Laboratoire Aime Cotton. An electrodeless lamp containing 50 μg of CmI3 was run for 12 hours and 800,000 points were taken. A total of 1743 lines have been ascribed to curium and 87 percent of the lines have been assigned to transitions between known energy levels
[en] Studies on fragment angular momentum in low energy fission of actinides provides information about the effect of nuclear structure such as shell closure proximity and odd-even effect. In order to examine these aspects in the even-odd fissioning system, in the present work independent isomeric yield ratios (IYR) of 130,132Sb, 133Te, 134,136I and 135Xe have been determined in the fast neutron induced fission of 244Cm (99.43 atom %) using off line gamma spectrometric technique
[en] The Curium Source Fabrication Facility (CSFF) at Oak Ridge National Laboratory (ORNL) was decontaminated to acceptable contamination levels for maintenance activities, using standard decontamination techniques. Solid and liquid waste volumes were controlled to minimize discharges to the ORNL waste systems. This program required two years of decontamination effort at a total cost of approximately $700K. 5 references, 7 figures, 2 tables
[en] Sorption of curium by silica colloids has been studied as a function of pH and ionic strength using 244Cm as a tracer. The sorption was found to increase with increasing pH and reach a saturation value of ∼95% at pH beyond 5.3. The effect of humic acid on the sorption of 244Cm onto silica was studied by changing the order of addition of the metal ion and humic acid. In general, in the presence of humic acid (2 mg/L), the sorption increased at lower pH (<5) while it decreased in the pH range 6.5-8 and above pH 8, the sorption was found to increase again. As curium forms strong complex with humic acid, its presence results in the enhancement of curium sorption at lower pH. At higher pH the humic acid present in the solution competes with the surface sites for curium thus decreasing the sorption. The decrease in the Cm sorption in presence of humic acid was found to be less when humic acid was added after the addition of curium. Linear additive model qualitatively reproduced the profile of the Cm(III) sorption by silica in presence of humic acid at least in the lower pH region, however it failed to yield quantitative agreement with the experimental results. The results of the present study evidenced the incorporation of Cm into the silica matrix.