A new inspection framework for nuclear power plants should be one that will support the autonomous efforts of power companies and lead toward enhanced safety.
The revised Nuclear Reactor Regulation Law, which was passed during the current Diet session, requires the Nuclear Regulation Authority (NRA) to make drastic reforms to its inspection framework.
The revised law takes into consideration the introduction of an inspection system, which is said to be advanced, from the United States.
Nuclear power plants in the U.S. boast a high degree of safety, suffer fewer disruptions and have operating rates as high as around 90 percent. The introduction of a flexible inspection system that takes into account actual situations at each plant is believed to have been effective.
The inflexibility of Japan’s inspection system has been laid bare before.
Typical examples include periodic checks that are conducted once every 13 months while suspending operations of nuclear reactors, and quarterly inspections for the safe management of nuclear installations. The Nuclear Regulation Agency submits a list of items to be checked to power companies in advance. The agency also conducts facility inspections in some cases.
However, under this method, ensuring the safety of items not on the checklist tends to be neglected. At the Fukushima No. 1 nuclear power plant, defective parts, such as valves to decrease pressure in anticipation of possible serious accidents, were overlooked in inspections, leading to the massive release of radioactive matter during the disaster.
A wave of nuclear power plants restarting in various parts of the country is sure to come. The new inspection framework must incorporate some of the lessons learned from the Fukushima disaster.
Inspectors’ skills need boost
Under the new framework, power companies, as the core entity, will conduct routine inspections of installations. The regulation agency will focus on scrutinizing the maintenance and inspection systems. When necessary, the agency will also conduct surprise inspections.
Have plants overlooked any abnormalities? Did they respond appropriately when they detected said abnormalities? The competence of those who work at nuclear power plants will be comprehensively evaluated on these fronts.
The capabilities of those who inspect installations must also be tested, so as not to overlook any lack of discipline. Items under scrutiny should be worked out in order of priority. Being overscrupulous about details that have little to do with basic safety will result in protracted inspection times while also lowering the morale of those at the work site.
In the United States, authorities introduced inflexible inspection procedures following an accident at the Three Mile Island nuclear power plant in 1979. As a result, the operating rate of nuclear power plants there dropped.
Now that there has been progress in reform, the framework has been improved to one where those nuclear power plants in which safety efforts are deemed to be excellent can have the checks streamlined. The frequency of periodic inspections on these power plants can be lowered.
Evaluations based on inspection results at each nuclear reactor are made public, with reactors graded according to safety.
The NRA has dispatched officials to inspection sites in the U.S. in a bid to introduce a framework similar to the one in the country. Based on this, the NRA will establish a system that would best suit Japan. It plans to increase the number of inspectors and to start operating the new framework in fiscal 2020.
Improved safety of nuclear power facilities will lead to effective utilization of the plants. Establishing a high-quality inspection framework is imperative.