In the transient state of natural and forced circulation, the soaring flux of coolant will lead to the variation of core temperature. Reactivity will also be changed because of the negative temperature coefficient. To study the disciplinarian of reactivity variation, a calculation model was established for reactor core and primary coolant system based on Matlab. The point-reactor kinetics equations were solved by third-order Hermite interpolation approach and fourth-order Runge-Kutta method was used to solve the heat transfer equations. In addition, the variation rule of coolant flux was calculated by one-dimensional flow model of the primary circuit. The results indicate that the coolant flux changes in conformity to hyperbolic tangent curve in the transient state. The coefficient k and flux rising multiple, W/W0, determine the flux grads and time for flux to steady. It can effectively improve the minimum reactor period to choose appropriate value of coefficient k in reactor design. And trying the best to reduce the flux grads of transient state can decrease the peak value of reactivity and increase the security of reactor.

This content is only available via PDF.
You do not currently have access to this content.