Calculation of kinetic parameters Tehran Research Reactor using MCNPX code and compare the results with perturbation method and reference

In this stady, (1 / v Poisoning Method) or perturbation method to calculate the kinetic parameters Tehran Research Reactor as Effective multiplication factor (Keff), effective delayed neutrons fraction (βeff) and prompt life time (ℓ) is used. . The purpose of this study is that there are errors in the values of these parameters especially neutron lifetime (ℓ) which is calculated first by MCNPX Code, shall be reduced and a more reasonable number To be earned. By working in this way is, the first, kinetic parameters of Tehran Reactor with enriched to 20% that Tehran Reactor now works with this Enriched ,calculated and Effective multiplication factor (Keff), effective delayed neutrons fraction(βeff), and the prompt lifetime (ℓ) is obtained. then some of poison that is boron is injected into the reactor and again this parameter is calculated. And finally, the values of these kinetic parameters calculated in both cases before and after the toxin injection, in particular, neutron lifetime (ℓ) with the reference value in the Tehran reactor (FSAR) were compared. Compare data show that the value of error, these parameters In particular neutron lifetime (ℓ) in the state after toxin injection is reduced and value of this parameters to the amount of those in Tehran reactor reference has been closer.