Determination of 36Cl in biological shield concrete using pyrohydrolysis and liquid scintillation counting

Abstract

A method for the determination of 36Cl in biological shield concrete of nuclear reactors was developed. Cl in the concrete sample was extracted quantitatively by pyrohydrolysis at 900 degrees C and recovered in Na2CO3 solution for subsequent measurement of 36Cl by liquid scintillation counting. WO3 was used as an accelerator in the pyrohydrolysis. The Cl extraction procedure was optimized by investigating experimental conditions with the use of ion chromatography and its recovery was evaluated by the analysis of the geochemical reference samples. The detection limit of 36Cl was 0.02 Bq g(-1) for a sample weight of 2 g. The relative standard deviation was 3-7% for the samples containing 0.5 Bq g(-1) levels of 36Cl. The method was applied to determine 36Cl in biological shield concrete of the Japan Power Demonstration Reactor.

Determination of Fluorine and Chlorine by Pyrohydrolysis and Ion Chromatography: Comparison with Alkaline Fusion Digestion and Ion Chromatography

“…(1994), h Anazawa et al. (2001), i Itoh et al. (2002), j Michel and Villemant (2003), k Govindaraju (1994).…”

Preliminary evaluation of 14C and 36Cl in nuclear waste from Ignalina Nuclear Power Plant decommissioning

“…Activity concentrations of 36 Cl in radioactive waste samples can be determined in a similar way as for 14 C using LSC techniques [16][17][18][19]. Digesting of radioactive waste samples can be performed using concentrated acids and acid mixtures as well as various modifications of the Fenton reaction and thermal destruction.…”

“…The basic principles of waste sample decomposition, 14 C and 36 Cl separation, and purification procedures are reviewed [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. The most common methods of the sample decomposition, including acid digestion, wet oxidation, and catalytic combustion, were used.…”

Critical comparison of radiometric and mass spectrometric methods for the determination of radionuclides in environmental, biological and nuclear waste samples

“…The interest in the determination of 36 Cl in nuclear waste results from the long half life of 36 Cl and its high mobility in the environment, while the purpose of determination of 36 Cl in the environmental sample normally focus on the application of this radionuclide as a environmental tracer. 36 Cl is a pure beta particle emitter with a high energy (E max = 708.6 keV, 98.1%), it is therefore mainly measured by beta counting such as LSC [129,130,[136][137][138][139][140][141]. The reported detection limit of LSC for 36 C is 14 mBq using Quantulus TM low level LSC for 50 min counting time [136].…”