South China Regional Office completes pre-critical nuclear safety inspection for Yangjiang Nuclear Power Plant overhaul

From September 14 to 17, the South China Regional Office of Nuclear and Radiation Safety Supervision of the Ministry of Ecology and Environment (hereinafter referred to as the South China Regional Office) organized an inspection team to conduct a pre-critical nuclear safety inspection of Unit 5 of Yangjiang Nuclear Power Plant for its sixth refueling overhaul (Y506 overhaul). This inspection was jointly carried out by the Nuclear Facility Business Division and the newly established Operation Special Division, adopting an organizational model of “two-division coordination and complementary expertise” to systematically verify the safety status of the unit after refueling and before criticality, thereby safeguarding the critical juncture for the safe startup of the unit.

The criticality of the unit after overhaul is a link in the nuclear safety management chain where risks are highly concentrated. With core refueling and loading completed, and maintenance, modification, and periodic testing items concluding in a concentrated manner, equipment status, personnel operations, and operational decisions converge at this point. The South China Regional Office closely focused on the core proposition of “whether the unit truly possesses the conditions for safe operation,” concentrating on key contents such as operating limits and conditions, availability of safety-important items, confirmation of post-maintenance equipment status and periodic test results, closed-loop rectification of outstanding issues from the previous overhaul, and handling of abnormal conditions, insisting on item-by-item verification and one-by-one clearance to ensure that no doubts are carried forward and no loose ends are left.

Compared with previous inspections, a distinctive feature of this inspection was the collaborative operation of the two divisions. The Nuclear Facility Business Division has long been stationed on site, familiar with the unit's operating history and in command of the safety management ledger; the Operation Special Division focuses on the specialized field of operational safety and possesses deep professional and technical penetration. One being “familiar” and the other “deep,” on-site experience and specialized perspectives mutually corroborate and complement each other, avoiding both the superficiality of judging problems by appearances and the vagueness of being detached from on-site reality, thereby significantly enhancing the pertinence and effectiveness of supervision.

This inspection was also an effective practice by the South China Regional Office in optimizing the allocation of regulatory resources and deepening “specialized + on-site” collaborative supervision, laying the foundation for subsequent pre-critical inspections of other unit overhauls in the South China region.