Standard Core Design and Safety Analysis for Advanced Power Reactor Plus (APR⁺)

Eleven units of Optimized Power Reactor 1000 MWe (OPR1000) are operating and one unit is under construction in Korea. And six units of Advanced Power Reactor 1400 MWe (APR1400) are under construction and additional construction of two units has been started from the beginning of 2012. They have been constructed continuously and repeatedly based on standardized concepts for designs and operating procedures. To have various reactor types for nuclear reactor export, Advanced Power Reactor Plus (APR⁺) had been developed based on the APR1400 technology. APR⁺ is an evolutionary type of two loop pressurized water reactor with a number of advanced design features to comply with regulatory and design requirements from many importing countries. The core power of APR⁺ increases up to 4,290 MWt for economic enhancement, which is corresponding to 1,500 MWe class nuclear power plant. Also, new construction technologies are adopted to shorten the construction period and several advanced design features are proposed for safety enhancement. The feasibility study for developing APR⁺ had been done to determine the top-tier requirements and identify the design concepts in viewpoints of safety, economics and performance. The preliminary evaluation had been completed for core designs, system designs and BOP (Balance of Plant) designs. The standard design had been completed based on the finalized design data at the end of 2011. In this paper, the results of the standard design in the area of core designs and safety analyses are introduced. Core designs for APR⁺ development had been carried out in the fields of physics, thermal-hydraulics, fuel rod and fuel assembly designs. The results confirm that the top-tier requirements and design concepts for APR⁺ are appropriate in viewpoints of the core safety and integrity because they can satisfy the current design requirements and bases established by the proven technologies. Relevant safety analyses had been performed to check whether the safety injection system with the DVI⁺ concept is adequate. The results show that DVI⁺ can provide the core cooling with enough safety injection capability, and new modeling approach is suggested based on experiment results to appropriately simulate the DVI⁺ concept using the current LOCA methodology. The results were implemented into Standard Safety Analysis Report (SSAR) and it was submitted to Korean nuclear regulatory authority, KINS to get the standard design approval by the end of 2012.