Japanese reactor shutdowns threaten power shortages

20 May 2011

Japan will face nationwide power shortages during the coming summer months unless reactors currently shut down for regulatory-mandated periodic inspections are allowed to resume operation, the head of the country's electric utility association has warned. 


Makoto Yagi, chairman of Japan's Federation of Electric Power Companies (Fepco), said that the organization expects the supply-demand balance this summer will be very tight in the eastern coast areas served by Tokyo Electric Power Co (Tepco), Tohoku Electric Power Co and Chubu Electric Power Co.


He said that all the utilities on the west coast of Japan will cooperate to transfer electricity to the east coast, noting the significant role of nuclear energy in ensuring a stable power supply. Therefore, he added, it is essential that the government allows those reactors currently shut down for regulatory-mandated periodic inspections to be able to return to service as soon as possible.


Yagi warned that should these units not be permitted to operate again before the start of summer, when electricity demand in Japan is at its highest, 'there was concern that the electricity reserve rate in west Japan based on this financial year's supply plan could fall below the appropriate level.'


He said that the government must help local authorities and residents understand the importance of restarting those reactors currently shut for periodic inspections.


Inspection rota


Under Japanese regulations, the default period between inspections at reactors is 13 months, but changes made in January 2009 allow operators to apply to increase this to 18 months. Subject to approval, a five year introductory period would follow, after which the limit could be raised to 24 months between inspections, more in line with international practices.


The median capacity factor for Japanese plants is about 70% - compared to over 90% for the best performers worldwide - with the country's inspection requirements a contributing factor to this gap. Most other countries conduct regulatory checks so that utilities can operate their power plants almost all the time that refuelling or major maintenance is not taking place.


According to data released by the Japan Atomic Industry Forum (JAIF), as of 16 May just 17 out of Japan's 54 nuclear power reactors were in operation. This represents 15,493 MWe, or 31.6%, of the country's total nuclear generating capacity of 48,960 MWe. Twenty units, with a combined generating capacity of 17,705 MWe (or 36.2% of total nuclear capacity) were not operating as they had been shut for periodic inspections, while another two units had been shut for unplanned inspections or equipment replacement.


Units 4 and 5 at Chubu Electric's Hamaoka plant have been shut down at the government's request and are unlikely to restart for at least several months. The other 13 units - with a combined capacity of 11,545 MWe (23.6% of total nuclear capacity) - have shut down as a direct result of the 11 March earthquake and tsunami. Nine reactors - units 1 and 3 of the Onagawa plant, unit 2 of the Tokai plant, all four units at the Fukushima Daini plant and units 5 and 6 of the Fukushima Daiichi - are in cold shutdown and it is not yet known when these will be allowed to resume operation. The remaining four units - Fukushima Daiichi units 1 to 4 - have been irreparably damaged and are to be decommissioned.


Tepco - owner of the Fukushima plants - now has only 4912 MWe of nuclear generating capacity in operation out of its total nuclear capacity of 17,308 MWe. It is making efforts to secure sufficient electricity supplies for its customers. In a statement, the company said, "We will steadily implement measures to secure enough supply capacity via the restoration of thermal power plants which were shut down due to damage from the earthquake and are now under periodical inspection, the restart of thermal power plants which are under planned long-term shutdowns, the installation of new gas turbines, the purchase of surplus power from non-utility generation facilities, and increased power purchases from other utilities."


It added, "We predict that our ongoing efforts to secure electricity supply will enable us to reach peak demand levels of approximately 55.2 GWe at the end of July and 56.2 GWe at the end of August." Tepco said, "We will also consider and implement measures to secure power supply capacity for this winter and next summer."




Yagi said that Fepco's members – Japan's ten regional electric utilities – would cooperate in the government's nuclear accident compensation scheme, which was announced last week. Under the plan, all of the country's nuclear operators would contribute to a fund for compensation for the Fukushima accident and any future nuclear accidents. He said, 'We agree that this scheme is important in the basic framework for swift compensation for those who have suffered from this disaster and the responsibility of Tepco to secure power supply.'


However, he stressed that the utilities want the government to pay a share of the compensation. 'The government itself promotes nuclear energy policy and the support of the government is clearly stipulated in the Nuclear Compensation Act,' Yagi said. He said that the government must limit the amount of compensation each utility must pay 'to a level which does not hinder stable power supply or credit from the financial market.'


Researched and written

by World Nuclear News