A Study on the Regulatory Technology for Lightning Protection and Grounding System in Nuclear Power Plants

원전낙뢰보호 및 접지계통에 대한 규제기술연구

The regulatory guide, RG-1.204 and its underlying or confirmatory research, NUREG/CR-6866 were studied for Korean application to LPGS of NPPs. However they excluded the application to that of NPPs. So US-NRC approved selectively industrial standards to that of NPPs on Nov 2005. It is necessary to understand the basis of regulatory technology related regulatory positions on LPGS and important to implement the guidance on LPGS as a resonable standard. The paper is examined what and how state of the art of relevant technology applied to the LPGS as well as the trip-out events related to electrical system were involved with LPGS. We reviewed the relevant standards applicable to Korean NPPs. Following are concluded to recommend. (1) IEEE 510-1050 is recommended as a guide for I&C grounding against EMI and lighting transients (2) IEEE Std-665, 510-666, Std-C62.23 for electrical grounding against voltage surges and lighting transients (3) Inspection should be thoroughly be implemented a frequency of 3-5 year period according to NFPA780 or KSC-IEC 61024.