METHOD AND APPARATUS FOR MEASURING BURN-UP DISTRIBUTION OF FUEL ASSEMBLY

• Main Authors: SAITO SHUNSUKE, ODANAKA SHIGERU, KUMANOMIDO HIRONORI
• Format: Patent
• Language: English
• Published: 14.06.2012
• Subjects: NUCLEAR ENGINEERING; NUCLEAR PHYSICS; NUCLEAR REACTORS; PHYSICS

PROBLEM TO BE SOLVED: To improve measurement reliability of burn-up distribution of a fuel assembly.SOLUTION: A radiation count is acquired at each fixed time interval by a gamma-ray detector which is arranged opposite to the side face of the fuel assembly and of which the relative position is moved at a fixed speed (step 1). One value Si is specified from a column of obtained radiation counts as a determination target (step 2). Three or more preceding/succeeding data including one data before the determination target and one data after the determination target are specified, and an approximate curve for measurement time values of the specified preceding and succeeding data is derived (step 3). A root mean square of a difference between the approximate curve and each of the preceding/succeeding data is calculated (step 4), a value Sf of the approximate curve at the measurement time Ti of the value Si is calculated (step 5), and a difference (d) between the values Si and Sf is calculated (step 6). A value A is calculated by dividing the difference (d) by the and a value B is calculated by dividing the difference (d) by the Sf. When each of absolute values of the A and B is larger than a determination value of each of the A and B, the Si is determined as abnormal data.