Solution of AER Benchmark Problem on Control Rod Worth of Paks VVER-440 by the Code DYN3D

This paper presents a solution of the AER benchmark problem specified for the 7th cycle of the Paks-2 VVER-440 reactor. The problem concerns control rod worth for both the beginning and the end of burnup cycle states. The burnup distribution of cycle 7 was calculated starting from the burnup values of the third cycle. The calculations were carried out by using the burnup option of the DNYN3D code and a MAGRU group data library. The results are compared with calculations published by other authors on AER meetings. Furthermore the influence on reactivity of some control rod properties typical for VVER-440 was studied.