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Emergency management of radiation accidents.

The Joint Committee on Accreditation of Hospitals requires that hospitals have a written procedure to cope with radiation accidents. Emergency personnel, specifically, should be prepared to manage radiation accident victims initially. Guidelines currently in use in over 15 hospitals in the United States include 1) advance notification to the hospital of arrival of such patients; 2) designated treatment area; 3) operating room attire; 4) perform life-saving functions first; 5) cover open wounds and remove clothing; 6) search for contamination with radiation detector, or 7) flush all wounds if no radiation detector is available; 8) wash patient; 9) evaluate internal and external radiation exposure, and 10) obtain medical consultation. For community hospitals, a less elaborate procedure will suffice for adequate handling of radiation accident victims and accreditation.

Accidents, Occupational↗

Development and application of a sorption data base for the performance assessment of a radwaste repository.

A sorption data base (SDB) provides readily available data for the performance assessment of a radwaste repository when site-specific and/or reference data are needed. The software developed at KAERI, SDB-21C, is a graphic user interface (GUI) program that provides efficient and user-friendly tools for evaluating large amount of sorption data. In addition, the most comprehensive sorption data base that contains about 11,000 NEA data and 2,000 KAERI data was compiled in the program. Besides the simple Kd approach, a parametric model and its compiled data sets are also included in the SDB-21C. In order to evaluate the versatility of SDB-21C, several applications were performed for relevant hypothetical situations.

Adsorption↗

Description and identification of difficulties arising from the application of a cleaning process in operating conditions for the treatment of components used on liquid metal fast reactors (LMFR). A technical designed approach to avoid these situations.

The cleaning process is one of the major maintenance operation for liquid metal fast reactors (LMFRs), both in operation and in their decommissioning stage. Russian and French cleaning processes are briefly described, including problems which have arisen during the processes. It appears that the cause of these problems is always connected to bad draining of the component, resulting in a vigorous reaction between vapour or liquid water and the bulk of sodium. From this discussion, the paper makes major recommendations for the efficient and safe cleaning of sodium wetted components, and proposes several processes which should be developed in order to deal with difficult situations, for example the removal of large amounts of undrainable sodium.

Chemical Precipitation↗

Optimization for solidification of low-level-radioactive resin using Taguchi analysis.

Solidification of low-level-radioactive (LLW) resin was optimized using Taguchi analytical methodology. The ingredients in LLW mortar which caused the solidification of cement were evaluated through consecutive measurements of the effects of various concentrations of ingredients. Samples selected according to Taguchi's method were separated into 18 different categories and measured at the 7th, 21st, and 28th day after fabrication on developing effects. Evaluations of the various samples focused on whether the compressive and bending strength fulfilled the special criteria of the Taiwan Power Company (TPC). Similar results indicated that both furnace slag and fly ash were the dominant material resulting from the solidification of LLW mortar. The superior combination was obtained as furnace slag 24 wt.%, fly ash 24 wt.%, and cement 8 wt.% to mix 24 wt.% of resin with 20 wt.% of water, to fulfill the contemporary requirements of TPC.

Incineration↗

Chemical speciation used to assess [S,S']-ethylenediaminedisuccinic acid (EDDS) as a readily-biodegradable replacement for EDTA in radiochemical decontamination formulations.

Preliminary investigations into the replacement of widely used chelating agents for industrial cleansing of radionuclide contaminated items using readily biodegradable alternatives which have equivalent effectiveness, have been made using chemical speciation simulation programs and databases such as the JESS system. The chelation of radionuclide cations by [S,S']-EDDS has been compared with traditional decontamination agents, EDTA and citrate. Models indicate that in many respects, [S,S']-EDDS compares favourably with EDTA.

Americium↗

Influence of glucose and urea on 125I transport across an anion exchange paper membrane.

In order to study the influence of glucose and urea on the 125I transport across an anion exchange paper membrane, the transmembrane potential, the fluxes, and the concentrations of 125I, glucose and urea within the membrane were measured in the Na125I concentration-cell system containing glucose or urea. Glucose and urea increased the membrane/solution distribution of the iodide ion, but scarcely affected the diffusion process of iodide ion within the membrane.

Glucose↗

High-level gamma dosimetry using phototransferred thermoluminescence in quartz.

Phototransferred thermoluminescence (PTTL) in natural quartz, separated from sand, has been studied for its application in high-level gamma dosimetry. The paper reports dose-vs.-PTTL response of 110 degrees C and 180 degrees C peaks in the dose range of 10 Gy to 6 kGy. Using this method, the dose rate delivered to the sewage sludge during irradiation at SHRI facility, Vadodara, India, was estimated to be 0.35 +/- 0.02 kGy/h.

Gamma Rays↗

Transport of 125I and 36Cl across an anion-exchange paper membrane.

The membrane characteristics controlling 125I and 36Cl transport across anion-exchange paper membranes are examined using three different paper membranes treated with different anion exchange groups: a trimethylhydroxypropylamino group, a diethylaminoethyl group, and a 50% quaternary diethylaminoethyl group. The membrane permeability for 125I is higher than that for 36Cl in all cases. Treatment with trimethylhydroxypropylamino group improves the 125I diffusion process, and the use of 50% quaternary diethylaminoethyl group improves the 125I solution/membrane distribution process.

Chlorine↗

Kinetics of isotopic exchange between strontium polymolybdate and strontium ions in aqueous solution.

A heterogeneous isotopic exchange reaction of strontium polymolybdate in strontium chloride solution was studied using 90Sr as a tracer. The effects of low and high strontium chloride concentration on the rate and mechanism of the isotopic exchange reaction were investigated. It was found that, at high concentrations, the rate is independent of strontium concentration, but, at low concentrations, the rate is proportional to the strontium concentration. These results support a hypothesis that, at low concentrations, the rate is controlled by film diffusion, whereas at high concentrations it is controlled by particle diffusion. Experiments were performed at 293, 303 and 313 K. Activation energy of isotopic exchange reaction and thermodynamic parameters deltaH*, deltaS*, and deltaG* were calculated using the Arrhenius and Eyring equations. The results also indicated that recrystallization is a predominant factor in the present exchange reaction.

Kinetics↗

Transfer of Eu (III) associated with polymaleic acid to Bacillus subtilis.

The aim of this study is to contribute to the understanding of the distribution of Eu(III) between dissolved organic matter and microorganisms, and to investigate the effect of competitive ions such as Ca(+2) on adsorption properties. Polymaleic acid (PMA), is used as synthetic organic matter, having similar properties as natural fulvic acid, and Bacillus subtilis is chosen as microorganism. A double labeling method was used: [14C]MPA and 152Eu to quantify the behavior of the various components. Preliminary experiments showed that the adsorption of polymaleic acid onto Bacillus subtilis was negligible at pH=5 in 0.15mol/l of NaCl. In the absence of Ca(+2), the transfer of Eu(III) from PMA to B. subtilis could be described by a simple empirical model based on data obtained from sorption isotherms on the reference systems Eu(III)/PMA and Eu(III)/B. subtilis. In the presence of Ca(+2), the transfer was increased. The hypothesis that Ca(+2) ions acted as a bridging agent between PMA and the bacteria was proposed.

Adsorption↗

Thermodynamic and kinetic investigations of uranium adsorption on amberlite IR-118H resin.

The adsorption behavior of uranium(VI) on a strongly acidic cation exchanger amberlite IR-118H has been studied as a function of the solution concentration and temperature. Results have been analyzed by Langmuir and Dubinin-Radushkevich (D-R) adsorption isotherms. The mean energy of adsorption 7.14kJmol(-1) was calculated from the D-R adsorption isotherm. In order to understand the significance of the diffusion mechanisms and to accurately estimate the diffusivities inside the adsorbent particles, a model for uranium(VI) adsorption on amberlite IR-118H was used. The rate constants have been calculated for 293, 313 and 333K using Lagergren equation and the activation energy (E(a)) was derived using the Arhenius equation. The thermodynamic quantities for the process of adsorption have been estimated by plotting Ln K(D) versus 1/T. The DeltaH(o) and DeltaG(o) values of uranium(VI) adsorption on amberlite IR-118H show endothermic heat of adsorption; higher temperatures favor the process.

Adsorption↗

A method to determine the time since last purification of weapons grade plutonium.

A non-destructive technique to determine the time since last purification of weapons grade plutonium based on the 241Pu decay series has been developed and demonstrated to provide results that are consistent with our historical and process knowledge. This method is based on the use of the Bateman equations and the decay chain 241Pu-->237U & 241Am-->237Np-->233Pa. Secular equilibrium is assumed between the (2.1 x 10(6) year) 237Np and the (27 day) 233Pa. The proposed method is dependent upon the efficiency of the plutonium separation process but makes no assumption about the relative abundance of 241Pu in 239Pu. Even though the technique was developed for weapons grade plutonium, it is expected to apply to almost any material that contains plutonium.

Algorithms↗

Low-resolution gamma-ray measurements of process hold-up.

This tool, consisting of software with a compact detector, an M3CA, and an Intermec datalogger: 1. acquires and manages several hundred spectra in an hour; 2. produces prompt and reliable quantitative analyses; 3. is self-powered, easily carried and operated by a single user; 4. accomodates varying degrees of user expertise; 5. corrects for the effects of equipment geometry; 6. corrects for the effects of equipment attenuation; 7. tolerates facility variables such as temperature fluctuations and equipment accessibility; 8. has been subjected to quality testing under field conditions; and 9. does not require extensive specialized training for the operators.

Calibration↗

Infrared spectroscopic study on the thermal decomposition of external and internal gelation products of simulated mixed oxide nuclear fuel.

The thermal decomposition of urania-ceria gel corresponding to the composition U(0.7)Ce(0.3)O(2+x) obtained through external and internal gelation routes were studied using infrared spectroscopy (IR). In the case of externally gelated compound, the gel decomposes with the release of H2O and NH3 below 500 degrees C. A part of the NH3 released is entrapped in the solid and above 500 degrees C self reduction occurs in which U(VI) in the gel is reduced to U3O8. The decomposition products were identified to be U3O8 and CeO2. In the case of internally gelated compound, decomposition similar to the one for externally gelated compound occurred below 500 degrees C. Above 500 degrees C the carbon present in the gel reduced U(VI) to UO2 which formed solid solution with CeO2 around 650 degrees C.

Cerium↗

Oxygen isotopic measurements by secondary ion mass spectrometry in uranium oxide microparticles: a nuclear forensic diagnostic.

To exploit oxygen isotopic measurement by SIMS as a diagnostic tool in nuclear forensics, the magnitude and reproducibility of 0-isotope instrumental mass discrimination for O-isotope standards in the SIMS laboratory at the Institute for Transuranium Elements has been evaluated. Tests for matrix-dependent discrimination effects on three different O-isotope standards with substantially different matrix compositions have been performed. The results were checked by an interlaboratory comparison of O-isotope discrimination with those obtained in the SIMS laboratory at the Lawrence Livermore National Laboratory on two standards. The results from the two laboratories are in very good agreement, indicating statistically indistinguishable instrumental mass discrimination factors for 180/160 ratios on the Cameca 6f and 3f, when the analyses are performed under the experimental conditions described. The 2sigma(mean) uncertainties of these factors are in the range of 0.3-0.9%. In accordance with the tested methodology, 0-isotope compositions were measured in three particulate uranium oxide samples of nuclear forensics interest.

Oxygen Isotopes↗