Study of Reactivity Effect on Reactor Power by Feedback Fuel Temperature

L. R. Ibrahim G, Farhan; Faissal G. H. Sabah, F.; F. Haora M. H, M.

	Study of Reactivity Effect on Reactor Power by Feedback Fuel Temperature
Diyala Journal For Pure Science
Article 1, Volume 9, Issue 2, 2013, Pages 72-91
Authors
Farhan L. R. Ibrahim G; F. Faissal G. H. Sabah; M. F. Haora M. H
Abstract
The study deals with insertion of step negative or step positive reactivity and/or ramp reactivity expressed as a polynomial in time in the presence of one feedback mechanism in order to predict the neutron behavior as a function of time in terms of reactor power. Insertion of negative step reactivity such as ρ = - 0.001 $ indicates that the reactor power is stable due to this value but insertion of larger negative step reactivates causes a decrease in power as a function to time while insertion of positive step reactivity such as ρ=0.007 $ shows that the reactor power stable but it increases with time in case of insertion of large positives reactivities despite of the presence of one feedback mechanism. Also, it is observed that the resulted reactivity due to insertion of positive reactivities in the range (0.2$ - 0.4$) will be stable for any time interval without being affected by feedback mechanism. He resulted reactivity due to insertion of positive reactivities in the range (0.45$ - 0.65$) will be stable for certain time interval and then decrease due to the effect of one feedback mechanism. The sudden jump in power (excursion) is observed during very short time after inserting positive reactivities in the range of (1.003$ - 2.5$) and continues oscillations occur in the power after the excursion in case of inserting positive reactivities in the range of (1.5$- 2.5$) despite the presence of feedback mechanism. Insertion of ramp reactivities in terms of polynomial in time to study the behavior of power and/or reactivity as a function of time in the presence of two feedback mechanism (fuel) has been carried out and the result are displayed as plots, and showed this results corresponding with international results. This study appeared proceeding determination present necessarily for reactivity effects values of safety analysis in transient and for control requirements through reactor operation.
Keywords
reactor kinetic; point reactor kinetic; accidents; feedback; reactivity insertions

Statistics Article View: 113 PDF Download: 75