Understanding using the Haling Power Depletion (HPD) as a guide for designing PWR cores

The Pennsylvania State University (PSU) is using the university version of the Studsvik Scandpower Code System (CMS) for research and education purposes. Preparations have been made to incorporate the CMS codes into the PSU Nuclear Engineering graduate class “Nuclear Fuel Management” course. The information presented in this paper has been developed during two phases of preparation of the material for the course. In the first phase, the Haling Power Depletion (HPD) was presented in the course for the first time. The HPD method has been criticized as not valid by many in the field even though it has been successfully applied at PSU for the past 20 years. It was noticed during the first phase that the radial power distribution (RPD) for low leakage cores during depletion remained similar to that of the HPD during most of the cycle and have close maximum normalized power values (NPmax’s) and cycle lengths. Thus, the Haling Power Depletion (HPD) may be used as a guide for conveniently designing mainly low leakage PWR cores because the HPD and actual core are similar. Studies were then made to better understand the HPD. Many different core configurations can be computed quickly with the HPD without using Burnable Poisons (BPs) to produce several excellent low leakage core configurations that are viable for power production. The first phase covered the solution to design a low leakage core for a cycle length of 16 GWD/MTU. Once the HPD core configuration is chosen as a potential core, it is followed by establishing a BP design to prevent violating any of the safety constraints during depletion. The problem to design a core for a cycle length of 18 GWD/MTU was not covered in the first phase. However, this cycle length has now been found to be beyond the scope of the course. Consequently, the cycle length is now assigned to be 17 GWD/MTU and the solution to this problem is covered in the second phase. Adding more BPs in this core for a solution than in phase one was more difficult to design. Consequently, techniques using the HPD results have been developed to help guide efficiently the placing of BPs in the core for a good solution. In this paper, the results of both phases of preparation for the course are presented.

► The Haling Power Depletion (HPD) may be used as a guide to design low-leakage cores.
► The paper presents studies that were performed to better understand the HPD.
► The first phase covered solution to design low leakage core for a given cycle length.
► Techniques using the HPD results are developed to guide placing of BPs in the core.