Incorporating tritiated water into a 14C-sampling system for quantitative estimation of 14C activity in airborne effluent

The effects of incorporating tritiated water into a ¹⁴C-sampling system in sample preparation and ¹⁴C activity measurement by liquid scintillation counting were investigated. Experiments derived the limit of water content in the prepared sample, and also demonstrated that ¹⁴C activity can be determined without any interference from ³H contamination for a clear-sample solution. The results enabled us to estimate the permissible relative humidity of air required for accomplishing sample preparation and ¹⁴C activity measurement. These showed that for sampling of air with less than the permissible relative humidity, total ¹⁴C activity in airborne effluent can be evaluated accurately without dehumidification of air.The authors would like to thank T. Kozawa, K. Isaka and Y. Adachi of Inspection Development Company Ltd., Y. Hiyama of Zuihou Sangyou Company Ltd., and T. Mizutani, H. Watanabe, M. Takeishi and K. Shinohara of Japan Nuclear Cycle Development Institute for their valuable assistance.     

Incorporating tritiated water into a 14C-sampling system for quantitative estimation of 14C activity in airborne effluent

The effects of incorporating tritiated water into a ¹⁴C-sampling system in sample preparation and ¹⁴C activity measurement by liquid scintillation counting were investigated. Experiments derived the limit of water content in the prepared sample, and also demonstrated that ¹⁴C activity can be determined without any interference from ³H contamination for a clear-sample solution. The results enabled us to estimate the permissible relative humidity of air required for accomplishing sample preparation and ¹⁴C activity measurement. These showed that for sampling of air with less than the permissible relative humidity, total ¹⁴C activity in airborne effluent can be evaluated accurately without dehumidification of air. This revised version was published online in July 2006 with corrections to the Cover Date.     

Incorporating tritiated water into a 14C-sampling system for quantitative estimation of 14C activity in airborne effluent

The effects of incorporating tritiated water into a ¹⁴C-sampling system in sample preparation and ¹⁴C activity measurement by liquid scintillation counting were investigated. Experiments derived the limit of water content in the prepared sample, and also demonstrated that ¹⁴C activity can be determined without any interference from ³H contamination for a clear-sample solution. The results enabled us to estimate the permissible relative humidity of air required for accomplishing sample preparation and ¹⁴C activity measurement. These showed that for sampling of air with less than the permissible relative humidity, total ¹⁴C activity in airborne effluent can be evaluated accurately without dehumidification of air. This revised version was published online in July 2006 with corrections to the Cover Date.     

Determination of chemical forms of 3H released to the atmosphere from the Tokai Reprocessing Plant

A method using a system with two sampling units was proposed to determine the chemical forms of tritium (³H) released into the atmosphere from the Tokai Reprocessing Plant (TRP). The main advantage of the method is that no carrier gas is required for sampling in the case when air to be sampled has high specific activity with tritiated hydrogen (HT). Investigations using this method showed that 19.1–28.3% of total airborne ³H was released as HT from the TRP during reprocessing operation. No clear relation was found between the ratios of HT release and the types of spent fuel reprocessed.The authors would like to thank T. Yokota, K. Isaka, T. Kozawa and Y. Adachi of Inspection Development Company, Ltd., Y. Hiyama of Zuihou Sanyou Company Ltd., and K. Miyabe, T. Mizutani, H. Watanabe, M. Takeishi and K. Shinohara of Japan Nuclear Cycle Development Institute for their valuable assistance.     

Determination of chemical forms of 3H released to the atmosphere from the Tokai Reprocessing Plant

A method using a system with two sampling units was proposed to determine the chemical forms of tritium (³H) released into the atmosphere from the Tokai Reprocessing Plant (TRP). The main advantage of the method is that no carrier gas is required for sampling in the case when air to be sampled has high specific activity with tritiated hydrogen (HT). Investigations using this method showed that 19.1–28.3% of total airborne ³H was released as HT from the TRP during reprocessing operation. No clear relation was found between the ratios of HT release and the types of spent fuel reprocessed.The authors would like to thank T. Yokota, K. Isaka, T. Kozawa and Y. Adachi of Inspection Development Company, Ltd., Y. Hiyama of Zuihou Sanyou Company Ltd., and K. Miyabe, T. Mizutani, H. Watanabe, M. Takeishi and K. Shinohara of Japan Nuclear Cycle Development Institute for their valuable assistance.     

Stability and reproducibility of gel-suspension samples for the liquid scintillation counting of14C using N-lauroyl-L-glutamic-α,γ-dibutylamide

Stability and reproducibility of gel-suspension samples were investigated in order to evaluate the characteristic feature of the gel-suspension method for¹⁴C activity measurement. Commercially available gelling agent, N-lauroyl-L-glutamic-α,γ-dibutylamide, was used for the gelformatio of the samples. No change of the counting rate for the gel-suspension sample was observed for more than 2 years after the sample preparation. Four samples used for checking the reproducibility of the sample preparation method. The same values were obtained for the counting rate of¹⁴C activity within the counting error. No change of the counting rate was observed for the “re-gelated” sample. These results show that the gel-suspension method is appropriate for the¹⁴C activity measurement by the liquid scintillation method and is useful for a long-term preservation of the sample for repeated measurement.     

Organic azo-dyes in quantitative analysis

Summary Chrom Red Brown 5 RD has been found as a sensitive reagent for the spectrophotometric determination of thorium. Concentrations as low as 1 g thorium/1 ml can be easily determined at wave length 485 nm. Sulphate, chloride, ferric and zirconium ions badly interfere, while Li, Na, K, Ni, Co, Cu²+, Cd, Ca, Mg and Cr³⁺ do not. U⁶⁺ and Ce⁴⁺ are permissible as traces.Part II: Zaki, M. R., and K. Shakir: Z. analyt. Chem. 177, 196 (1960).     

Comparison of two methods for 14C analysis from essential oils using LSC

Natural essential oil sample obtained from basil (Ocinum basilicum), and ethanol sample obtained from wine were measured to determine ¹⁴C specific activity, using two different sample preparation methods, and liquid scintillation counting method. The paper describes the use of two preparation methods, direct measurement method and CO₂ absorption method, and the results obtained for this comparative study. Depending on carbon content of the sample and bubbling time, different correction factors of carbon mass trapped in liquid scintillation cocktail were established for CO₂ absorption method.

     

Distribution of 14C and 3H in low level radioactive wastes generated by wet waste streams from pressurized water reactors

Summary It is impossible to detect ¹⁴C and ³H by direct methods such as γ-spectroscopy because they are pure b-emitters and thus they are classified as hard to measure nuclides (HTM). In this paper the analysis results of ¹⁴C and ³H in the low level radioactive wastes (LLWs), including spent ion exchange resin, evaporated bottom and sludge are presented. The LLWs were generated by three nuclear power plants (NPPs), in Korea all with pressurized water type reactors (PWRs). A simultaneous separation procedure for ¹⁴C and ³H in LLWs was established by wet oxidation-acid stripping. A liquid scintillation analyzer was used for the measurement of ¹⁴C and ³H. It was found that the recovery of ¹⁴C and ³H was 82-99 and 78-103%, respectively, by wet oxidation-acid stripping with diluted standard solutions. At the lowest injection of ¹⁴C and ³H, i.e., at 1.44 Bq for ¹⁴C and 1.22 Bq for ³H, the minimum detectable activity (MDA) of ¹⁴C and ³H was calculated as 0.88 and 0.78 Bq/g, respectively, for the minimum allowable sample weight, using wet oxidation and 16 wt% H₂SO₄ acid. By the wet oxidation-16 wt% H₂SO₄ stripping method no interfering nuclides were detected in the trapping solution of ¹⁴CO₂ and the distillate of ³H. The activity concentration range of ¹⁴C in the analyzed samples, i.e., spent ion exchange resin, evaporated bottom and sludge, was 0.17-110,000, 8.4-1380 and 0.1-10,006 Bq/g, respectively, and that of ³H in the same was from no detectable to 769, 134-14,383 and 0.7-4820 Bq/g, respectively.     

A simple and reliable monitoring system for 3H and 14C in radioactive airborne effluent

Summary A simple and reliable sampling system for ³H and ¹⁴C in airborne release from nuclear facilities was designed. The sampling system can collect ³H and ¹⁴C simultaneously with a condensation technique using a commercially available cold trap equipment and a CO₂ absorption technique using an organic alkali monoethanolamine solution, respectively. In situ performance tests for the effluent from a reprocessing plant showed that the system has high and stable efficiencies for collecting ³H and ¹⁴C for a one-week batch sampling at a sampling flow rate of 0.4 l ^. min^-1. These collection techniques also provided a simple procedure of following sample preparation for activity measurements by liquid scintillation counting. The detectable concentrations of the proposed monitoring method were 3.0 Bq ^. m^-3 for ³H and 1.6 Bq ^. m^-3 for ¹⁴C, respectively. The sensitivity would be on an acceptable level for routine monitoring of airborne release at nuclear facilities.     

Simple measurement of14C in the environment using a gel suspension method

A simple analytical method for environmental¹⁴C with a low background liquid scintillation counter was developed. We used a new gelling agent, N-lauroyl-L-glutamic-α,γ-dibutylamide, for the liquid scintillation counting of¹⁴C as CaCO₃ (gel suspension method). Our procedure for sample preparation was much simpler than that of conventional methods and required no special equipment. The samples prepared with the standard sample of CaCO₃ were measured to evaluate the self absorption of the sample, the optimum condition of counting and the detection limit. Our results indicated that the newly developed technique could be efficiently applied for the monitoring of environmental¹⁴C.     

Synthese und Oxidation von14C-kernmarkierten Bikreosolen

Bicreosol, labelled with¹⁴C in ring position 1.1-, 4.4-, 5.5-, in the methyl- or in the methoxy substituent was oxygenated in 0.25m-NaOH. Isolation of low molecular fragments and determination of their specific activities indicate that at least two fragmentation pathways take place simultaneously: one with ring opening between the oxygen substituted carbon atoms, and one in which the bond between these atoms is not cleaved.

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Meinem Lehrer, Herrn Prof. Dr. Dr. h.c. mult.H. Mark, zum 80. Geburtstag gewidmet.

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3. Mitt.:K. Kratzl, P. Claus undf. W. Vierhapper, Mh. Chem.103, 100 (1972).     

Ger?te zur Ionenaustausch-Chromatographie im Mikroma?stab

Ohne ZusammenfassungÜber das Gerät und seine Anwendungen vgl. Schnitger, H., K. Papenberg, E. Ganse, R. Czok, T. Bücher u. H. Adam, Biochem. Z. 332, 167 (1959).     

A one-year study of the total air-borne14C effluents from two Swedish light-water reactors,one boiling water- and one pressurized water reactor

The results of a one-year study of the total air-borne¹⁴C effluents from two Swedish light-water reactors, one boiling water reactor (BWR) at Forsmark and one pressurized water reactor (PWR) at Ringhals, are presented. Air emitted from the stacks has been collected continuously over two-week periods and the¹⁴C content in the samples has been analysed using accelerator mass spectrometry (AMS). The¹⁴C activity concentration in the air issuing from the stack of the PWR varied between 2 and 1132 Bq/m³ with a mean value of 200 Bq/m³, while from the BWR the activity concentration varied between 4 and 146 Bq/m³, with a mean value of 95 Bq/m³. The corresponding¹⁴C release rate was 0.27 TBq/GW_el·year for the PWR and 0.48 TBq/GW_el·year for the BWR. During the same period of time, for comparison, the¹⁴C activity in continuously collected air from the stack of the PWR was also measured by liquid scintillation counting. In most cases the results of these measurements were in fair agreement with the corresponding AMS results.     

Detailed assignments of 1H and 13C NMR spectral data of 14 cyclopentane derivatives

Detailed assignments of ¹H and ¹³C NMR spectral data for 14 cyclopentane derivatives are reported. The assignments are based on 1D ¹H and ¹³C NMR and on 2D shift‐correlated [¹H, ¹³C‐HMQC], J‐resolved and NOEDIF experiments. Copyright © 2003 John Wiley & Sons, Ltd.     

Rapid determination of tritium and carbon-14 in urine samples using a combustion technique

Traditionally in bioassay monitoring, ³H determinations in urine have been performed using either direct counting (with or without sample decolourisation) or distillation whilst ¹⁴C has been determined on separate sub-samples following chemical isolation of the carbon from samples. Although these techniques are relatively straightforward they do not permit simultaneous determination of ³H/¹⁴C. For ³H, direct counting can be significantly affected by variations in sample composition/colour resulting in varying degrees of sample quench, does not distinguish between aqueous/organically-bound ³H and is limited to small sample sizes. This study describes the use of purpose built multi-tube combustion furnace for the simultaneous extraction and determination of ³H and ¹⁴C. The technique is insensitive to sample composition and can be adapted to measure Tritiated water (HTO) and organically bound tritium separately. The development of a multi-tube system with integrated cool-down facility permits rapid throughput of high sample numbers and has been proven effective in decommissioning waste characterisation. In addition, the furnace-based technique is capable of processing larger sample sizes, increasing analytical sensitivity and accuracy of dose assessment.     

Die gaschromatographische Direktanalyse von Pilzduftstoffen in der Hauptwachstumsperiode und bei Hemmstoffzusatz

Ohne Zusammenfassung Sprecher, E., u. K. H. Strackenbrock: Z. Naturforsoh. 186, 495 (1963).     

Zur Reaktion von Germaniums?ure mit ?thylendiamintetraessigs?ure

Zusammenfassung Germaniumsäure reagiert mit den Formen H₄Y und H₃Y- der Äthylendiamintetraessigsäure unter Bildung von 11-Komplexverbindungen mit den folgenden Stabilitätskonstanten: K _H4Y=6.27·10⁴ bzw. K _H4Y=5.99·10⁴ und K _H3Y=3,78·10⁴ bzw. K _H3Y=2,35·10⁴ (25°C; Ionenstarke 0,1 m), je nachdem, mit welchen Werten für die Dissoziationskonstanten der ÄDTE gerechnet wird.

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Summary Germanic acid reacts with the species H₄Y and H₃Y- of EDTA forming 11 complex compounds. The following stability constants have been obtained: K _H4Y=6.27x10⁴ resp. K _H4Y=5.99x10⁴ and K _HaY=3.78x10⁴ resp. K _H2Y=2.35x10⁴ (25°C; ionic strength 0.1 m), depending on the values inserted for the dissociation constants of the EDTA.

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Herrn Prof. Dr. M. von Stackelberg zum 70. Geburtstag gewidmet.

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Herrn Prof. Dr. H. Nowotny danke ich für wertvolle Diskussionen. Bei der Ausführung der Experimente haben mich in dankenswerter Weise vor allem Herr A. Grumer, ferner Frl. L. Docekal, Frl. E. Hofmeister und Herr P. Angelbeger unterstützt.