用重同位素比值法测量反应堆元件的燃耗

MASS SPECTROMETRIC DETERMINATION OF BURNUP BY URANIUM ISOTOPIC RATIO METHODS

文章介绍了用综合的铀同位素比值法测量浓缩铀反应堆元件的燃耗:首先测量辐照前、后元件铀同位素比值,由R_(6/5)比值和α_5计算燃耗值B_(U1)(％),然后用3—4片的B_(U1(％)或B_(U0)(％)(^(148)Nd——剩余铀含量法)计算α_(5·8),制作α_(5·8)——B_U(％)关系曲线。求出通用的α_(5·8)=F[B_U(％)]表达式,由R_(5·8),R(6/8)比值和α_(5·8)表达式用数值逼近法计算所有片号的燃耗值B_(U2)(％)。B_(U1)(％),B_(U2)(％)在2.0％内一致,与B_(U0)(％)在2.5％内符合。

The mass spectrometric determinations of burnup in rich uranium fuels by uranium isotopic ratio methods were described in this paper: First, the burnup-values B_(U1)(%) were calculated from uranium isotopic ratios R_(6/5) before and after irradiation in rich-uranium fuels and α_(5·) Second, the α_(5·8)-values were obtained from B_(U1)(%), B_(U0)(%) (^(148)Nd -spent-uranium concentrations method), and R_(5/8), R_(6/8) before and after irradiation of 3—4 pieces of uranium fuel. Third, the correlative curves of α_(5·8) versus burnup-values B_U(%)in irradiated fuels were drawn, α_(5·8)=F (B_U(%)) also were induced from this curves. FinaIy, the burnup-values B_(U2)(%) were counted from α_(5·8) and R_(5/8), R_(6/8), before and after irradiations, the burnup-values of B_(U1)(%) and B_(U2)(%) were in good agreement。 The B_(U1+2)(%) and B_(U0)(%) were agreed within 2.5%.