Implementation of Additional Safety Measures for Hamaoka Nuclear Power Station Units 3 and 4 in accordance with New Regulatory Requirements
September 25, 2013
Chubu Electric Power Co.,Inc.
Seeking to conform as rapidly as possible to the new regulatory requirements introduced by the Nuclear Regulation Authority in July 2013, Chubu Electric Power has conducted successive studies of the responses that will be necessary.
As a result of this process, we have decided to implement a set of additional safety measures based on the new requirements, to be introduced to Hamaoka Nuclear Power Station Units 3 and 4. Work to introduce these additional measures is scheduled to be completed at the end of September 2015 in the case of Unit 4 and at the end of September 2016 in the case of Unit 3.
In relation to design basis for nuclear power stations, the new regulatory requirements have specified new essential requirements and enhanced other requirements in order to respond to a variety of natural phenomena including tornados, in addition to earthquakes and tsunami, and also events such as fires. The standards have further established new essential requirements to prevent or mitigate the effects of severe accidents such as damage to the reactor core occurring as a result of events exceeding the design basis.
Chubu Electric Power has previously voluntarily introduced countermeasures for tsunami and severe accidents, but the new regulatory requirements have stipulated essential requirements that demand the consideration of further countermeasures and concrete responses. We have therefore proceeded with studies of these necessary responses.
As a result, we have decided to implement additional measures in Units 3 and 4 in order to enhance functions including the ability to inject water into the reactors and to guarantee a power supply as measures to respond to earthquakes, tornados, fires, and severe accidents. (For an overview of the additional measures, please see Additional Materials 1.) Studies of additional measures for Unit No. 5 are proceeding.
Taking into consideration factors including the status of progress of design and the amount of work to be performed, the implementation of the new measures will commence in Unit 4, moving then to Unit 3. The congestion of the worksites will necessitate an extended construction period, and we are targeting completion of the work on Unit 4 for the end of September 2015, with work on Unit 3 to be completed at the end of September 2016. We will reflect the designs and other aspects of the additional measures in the measures already underway, and will complete work on them by the date of completion of the additional measures. in the tsunami and severe accident countermeasures currently being put in place.
We believe that the implementation of these additional measures will make Units 3 and 4 fully compliant with the new regulatory requirements in terms of facility- and equipment-based measures. (Please see Additional Materials 2 for details of the status of our response to the new standards.)
We will proceed with the necessary preparations to enable us to make applications related to conformity with new regulatory requirements as early as possible within the current fiscal year.
Chubu Electric Power will engage all its resources in the sure and steady effort to further enhance the safety of Hamaoka Nuclear Power Station. We are also committed to providing detailed explanations of the substance of those efforts in order to contribute to the relief of local residents and society at large.
*Severe accident measures including the installation of filter vent equipment announced in December 2012