抄録
An experimental study of the void coefficient of reactivity in HTR was carried out. The experiment consisted of an out-of-pile experiment on void ratio calibration and an in-pile experiment on reactivity measurement.
A stream of nitrogen gas was introduced through a pipe to the bottom of a fuel channel to produce a rising column of void bubbles. The reactivity was derived from either rod position or positive period.
The local void coefficients measured were:
(a) Single channel void coefficient
(b) Two channel void coefficient
(c) Three channel void coefficient
From (a), (b), (c) the average void coefficient of HTR was determined to be Δk/k=-1.4×1.07×10-3/%void.
