Standard No.:	GB/T 44647-2024
English Name:	Determination of heavy water isotopic purity—Fourier transform infrared spectroscopy
Chinese Name:	重水同位素纯度的测定 傅里叶变换红外光谱法
Chinese Classification:	F60    Nuclear reactor in general
Professional Classification:	GB    National Standard
ICS Classification:	27.120.10 27.120.10     Reactor engineering 27.120.10
Source Content Issued by:	SAMR, SAC
Issued on:	2024-09-29
Implemented on:	2024-9-29
Status:	valid
Target Language:	English
File Format:	PDF
Word Count:	12500 words
Translation Price(USD):	375.0
Delivery:	via email in 1~3 business day

Determination of heavy water isotopic purity - Fourier transform infrared spectroscopy 1 Scope This document specifies an analytical method for determining heavy water isotopic purity by Fourier transform infrared spectroscopy (FTIR). The method can be applied for heavy water isotopic purity measurements in a heavy water reactor power plant or research reactor, heavy water production factory and heavy water related areas. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3696, Water for analytical laboratory use - Specification and test methods 3 Terms and definitions For the purposes of this document, the following terms and definitions are applied. ISO and IEC maintain terminological databases for use in standardization at the following addresses: ——IEC Electropedia: available at http://www.electropedia.org/ ——ISO Online browsing platform: available at http://www.iso.org/obp 3.1 heavy water water which contains a higher than normal proportion of the heavy isotopes of hydrogen in combination with oxygen Note 1: HDO exists whenever there is water with hydrogen-1 and deuterium in the mix. HDO is formed when hydrogen and deuterium atoms are rapidly exchanged between light water and heavy water molecules. Note 2: Heavy water here does not mean “heavy water” which is enriched in the heavier oxygen isotopes 17 O and 18 O. Note 3: The ice point of heavy water is as high as 3.8 °C, care should be taken to avoid heavy water from freezing. [SOURCE: ISO 6107:2021, 3.272, modified.] 3.2 light water water that contains natural abundance of protium and deuterium 3.3 Fourier transform infrared spectroscopy; FTIR method in which a sample is subjected to excitation of molecular bonds by pulsed, broad-band infra-red radiation and the Fourier transform mathematical method is used to obtain an absorption spectrum [SOURCE: GB/T 30544.6-2016, 4.8] 3.4 D2O molecular formula of deuterium oxide 3.5 heavy water isotopic purity catom percentage of deuterium atoms in the total number of all hydrogen atoms including deuterium, protium and tritium atoms Note: Expressed as atom%. 3.6 D2O concentration cmass percentage of the mass of D2O in total water mass, assuming that all of the deuterium exist in the form of D2O Note 1: Expressed as mass fraction. Note 2: The mass percentage of D2O is deduced from heavy water isotopic purity which does not precisely mean the mass percentage of D2O in water because deuterium exists both in the form of HDO and D2O. 3.7 precision closeness of agreement between independent test results/measurement results obtained under stipulated conditions [SOURCE: GB/T 3358.2-2009, 3.3.4] 4 Principle HDO, D2O and H2O co-exist in heavy water, with Formula (1): The O-H bond and the O-D bond have each different infrared spectroscopy. Heavy water isotopic purity is proportional to the absorption strength of characteristic region in infrared spectrum within certain range of heavy water concentration. Almost all protium in high isotopic purity heavy water, like a mass fraction from 98.500 to 100.000 in %, exists in the form of HDO, in which O-H has the biggest absorption at infrared wave number about 3 400 cm−1 (λ is 2.94 μm). The absorption strength of this specified infrared wave number is proportional to protium isotopic purity and proportional inversely to the deuterium isotopic purity in heavy water. Almost all deuterium in low concentration of heavy water, like a mass fraction from 0.05 to 2,00 in %, exists in the form of HDO, in which O-D has the biggest absorption at infrared wave number about 2 500 cm−1 (λ is 4.00 μm). The absorption strength of this specified infrared wave number is proportional to deuterium isotopic purity and proportional to heavy water concentration. For heavy water concentration in the range of a mass fraction from 2.00 to 98.50 in %, different ranges could be subdivided according to different interested regions of the spectra respectively.