Nuclear Power Plant Management Processes for Indian HWRs

The Indian government, in response to the Fukushima accident, through the words of the Honourable Prime Minister of India, took the position that the safety of nuclear power plants is a matter of the highest priority for the country and consequently ordered safety audits of all operating nuclear power plants as well as those under construction. Major findings of the assessment of plants by utilities were that the existing nuclear power plants' designs meet regulatory requirements for externally initiated events. They are in a position to ensure core cooling in the absence of off-site and on-site power supplies, and they have on-site water storage for decay heat removal. There are procedures to handle external events, loss of UHS and station blackout. In addition, vulnerabilities to extreme beyond design events were identified and in response, to further enhance safety, the auditors recommended incorporating automatic reactor trips in all nuclear power plants for seismic events, and to strengthen provisions for beyond design basis accidents. In addition, they provided means for augmentation of on-site water supplies, provided smaller diesel generator sets for charging batteries and running small capacity pumps, and incorporated extra provisions to enhance containment safety and fuel pool safety and to formalize and implement severe accident management guidelines. In terms of external event assessments, the auditor recommended that plants review the magnitude of postulated design basis natural events and the related requirements for siting and design of nuclear power plants as specified in the Atomic Energy Regulatory Board (AERB) safety regulations, which are appropriate and sufficiently conservative. However, in light of the Fukushima experience, it is prudent to further enhance this conservatism and also postulate beyond design basis natural events