Development of a Physics-Based Monitoring Algorithm Detecting CO2 Ingress Accidents in a Sodium-Cooled Fast Reactor

Abstract

One of the benefits of the supercritical CO 2 Brayton cycle in Sodium-cooled Fast Reactors is an enhanced plant safety, since potential reactions of CO 2 with liquid sodium have been reported to be less stringent than a sodium-water reaction found in the Rankine cycle. However, moderate chemical interactions between CO 2 and liquid sodium make detecting CO 2 ingress accidents harder. Thus, this paper proposes a new physics-based detection algorithm by comparing the real-time pressure measurements of two identical heat exchangers for the early detection. The CO 2 ingress occurs owing to a crack at the pressure boundary wall, a certain self-recovery of structural damage does not happen over time, and an accident probabilistically starts at only one component of two. The proposed physics-based method with the probabilistic analysis was compared to the pure data-based method. Finally, the damage degradation was developed with a simplified mass and energy transfer model, and the proposed algorithm was verified with experimental data. The results show that a 99.99% detection probability can be achieved for the air ingress of 30 cc/s, which is equivalent to the 0.12 g/s CO 2 ingress, in a 70 s detection time, limiting down to 0.1% false alarms due to sensor noise.

A Study on Improvement of Blockchain Application to Overcome Vulnerability of IoT Multiplatform Security

“…This book is made up of cryptographic techniques that cannot be falsified, and the digital book-wherein transactions of cryptography are recorded publicly for the transfer of ownership of the bitcoin-also starts from the first block (Genesis Block) [46,47]. The blockchain, which refers to all the transaction information of the chain including information on the previous block, is started from being distributed and stored across several nodes Figure 3 [8]. There are three types of blockchains: public, private, and consortium Table 2.…”

“…In Russia, domestic and overseas CCTV videos are watched and recorded in real time, and CCTV videos of personal and public spaces such as department store space are hacked, recorded, and In addition, for sensor multi-platforms, 10 billion IoT devices are expected in 2014, and more than 20 billion, in 2017 [8,9]. Likewise, blockchain technology is forecast to be applied in various fields of the Internet, and blockchains can be introduced for data management, transaction, or authentication.…”

“…In addition, since IoT devices have a lot of security weaknesses we intend to show the authentication strength of security through the color spectrum chain and apply it to sensor and multi-platform using Blockchain in the future.Energies 2019, 12, 402 2 of 29 circulated. Although in Korea, sites providing those videos are blocked as harmful, it is possible for foreigners to watch all hacked CCTV videos in their countries.The biggest problem with IoT security is that "there is no biggest problem [6][7][8]." IoT has more complex specifications than traditional information technology (IT) infrastructure.…”

“…In this paper, we make a proposal based on this blockchain-based BoT (Blockchain of Things).Energies 2019, 12, 402 2 of 29In Russia, domestic and overseas CCTV videos are watched and recorded in real time, and CCTV videos of personal and public spaces such as department store space are hacked, recorded, and circulated. Although in Korea, sites providing those videos are blocked as harmful, it is possible for foreigners to watch all hacked CCTV videos in their countries.The biggest problem with IoT security is that "there is no biggest problem [6][7][8]." IoT has more complex specifications than traditional information technology (IT) infrastructure.…”

“…The biggest problem with IoT security is that "there is no biggest problem [6][7][8]." IoT has more complex specifications than traditional information technology (IT) infrastructure.…”