Interlaboratory Comparison for Boron Isotope Ratio Measurement with Inductively Coupled Plasma - Quadrupole Mass Spectrometer

Abstract

B U N S E K IBoron isotope ratios were analyzed in seven domestic analytical labs for boric acid solutions with various compositions of boron isotope abundances, using an Inductively Coupled PlasmaQuadrupole Mass Spectrometer (ICP-QMS). Five sample solutions with different isotope abundances of 10 B were prepared in the range of 10 to 20％ by mixing two boric acid solutions containing natural B and enriched 11 B, respectively. Then, the 10 B isotope abundances of each sample were certified by analyzing with thermal ionization mass spectrometry (TI-MS) according to ASTM-C791-04. Results obtained from each lab have indicated good coincidences with TI-MS results. Also, the relative standard deviations of results with ICP-QMS of seven analytical labs were 0.11 to 0.81％. The measurement precision for ICP-QMS would be sufficient in terms of practical use, while taking into consideration a valid requirement required for verifying a depletion of the 10 B isotope abundance in the PWR coolant, while this is greater than a nominal analytical error (relative value : 0.22％) for TI-MS shown in ASTM-C791-04.

Measurement of the isotopic abundance of boron-10 by inductively coupled plasma-quadrupole mass spectrometry

“…Boron has two stable isotopes 10 B and 11 B. The isotopic ratio of boron ( 10 B/ 11 B) in stones and the soil has often been used as a geochemical indicator of the origins and histories of the materials.…”

“…In the nuclear reactors, neutron absorption is mainly performed by 10 B because 10 B has a much greater neutron absorption cross-section than that of 11 B. For example, the neutron absorption cross-section of 10 B is 3840 barn and that of 11 B is essentially zero (50.01 barn) for thermal neutrons [1,2].…”

“…For example, the neutron absorption cross-section of 10 B is 3840 barn and that of 11 B is essentially zero (50.01 barn) for thermal neutrons [1,2]. For fast neutrons with energy E^0.1 MeV, the neutron absorption cross-section of 10 B becomes about 1 barn and that of 11 B is negligibly small. Thus, the isotopic abundance of 10 B is one of the most important factors that characterize the quality of B 4 C or H 3 BO 3 .…”

“…For fast neutrons with energy E^0.1 MeV, the neutron absorption cross-section of 10 B becomes about 1 barn and that of 11 B is negligibly small. Thus, the isotopic abundance of 10 B is one of the most important factors that characterize the quality of B 4 C or H 3 BO 3 . In Japanese nuclear reactors, the accuracy of measurements specified for the isotopic abundance of 10 B in B 4 C (natural or enriched) for BWR and FBR is 0.2% as the relative standard deviation (0.2% RSD).…”

“…Thus, the isotopic abundance of 10 B is one of the most important factors that characterize the quality of B 4 C or H 3 BO 3 . In Japanese nuclear reactors, the accuracy of measurements specified for the isotopic abundance of 10 B in B 4 C (natural or enriched) for BWR and FBR is 0.2% as the relative standard deviation (0.2% RSD). Therefore, it is important to measure the isotopic abundance of 10 B with high reproducibility.…”