**6. Conclusion**

Digital computers are used to simulate and analyze reactor core. For introducing parallel computing and promoting the efficiency, the core calculation with the integrated software structure is explored, which can provide the methodology of nuclear data, control layers, and parallel algorithms. The main software structure is discussed, and multiple parallel algorithms are analyzed concisely for sample core programs, with the corresponding conclusions as follows:


It is necessary to establish systematic knowledge and suggestions for software approach and parallel algorithm development in reactor core calculation. On the one hand, it can integrate reusable patterns into computation, such as the instance of prototype software NAC4R. On the other hand, it can explore and record more specific parallel algorithms in this field.
