Analyses of LOFT LP-FW-1 using SPACE code

• Published in: Annals of nuclear energy 2020-01, Vol.135, p.107001, Article 107001
• Main Authors: Choi, Chiwoong, Ha, Kwi-seok, Kim, Kyung Doo
• Format: Article
• Language: English
• Subjects: DEC; LOFT; LP-FW-1; Multiple failure accident; SPACE; TLOFW
• ISSN: 0306-4549; 1873-2100
• DOI: 10.1016/j.anucene.2019.107001

•The sensitivity analysis for the discharge coefficients in the critical flow model of the PORV, heat losses are conducted.•Data assimilation is carried out using PAPIRUS. It suggested that the two times higher heat loss and two-phase discharge coefficient of 1.08 for the better prediction.•Using FFTBM, the accuracy of SPACE results are quantitatively evaluated. It shows the AA value of 0.027, which indicates the good prediction of SPACE code for the LOFT LP-FW-1. The validation analysis of the SPACE code using the LOFT LP-FW-1 test was done to evaluate the applicability and accuracy of the SPACE code for the simulation of total loss of feed-water (TLOFW), which is one of the essential multiple failure accidents that needs to be analyzed in the design extended condition (DEC). Sensitivity analyses were done for the major transient parameters such as the discharge coefficients of the critical flow model in the PORV, the heat loss. In addition, a data assimilation was performed for highly sensitive parameters including the two-phase discharge coefficient and heat loss. From these results, it was found that the initial heat loss input is under-estimated. Moreover, the accuracy of the final assimilated results was quantitatively evaluated using FFTBM. In conclusion, the applicability and accuracy of the SPACE code for total loss of feed-water (TLOFW) was evaluated.