Accurate measurement of the reactivity worth of safety rods is very important for the safe reactor operation. in normal and emergency conditions. In this paper. the reactivity worth of safety rods in Heavy Water Zero Power Reactor (HWZPR) in the new lattice pitch is measured by advanced source jerk method. https://www.hindigyanvishv.com/super-find-Red-Pygmy-reg-Dogwood-Tree-limited-super/