News Watch 166 June/July 2015 -Nuke Info Tokyo No. 166
Five Superannuated Reactors Decommissioned
2030 Electric Power Generation Cost Estimations
Investigation of Interior of Fukushima Daiichi Unit 1 Reactor Containment Vessel Commences
Three Methods Proposed for Removing Fuel Debris
Five Superannuated Reactors Decommissioned
Decommissioning began on the Tsuruga NPP Unit 1 (BWR, 367 MW), Mihama NPP Units 1 and 2 (PWR, 340 MW and PWR, 500 MW, respectively) and Genkai NPP Unit 1 (PWR, 559 MW) reactors on April 27, and on the Shimane NPP Unit 1 reactor (BWR, 460 MW) on April 30. On the other hand, Kansai Electric Power Company (KEPCO) filed a petition on April 30 to extend the operating lives of the Takahama NPP Unit 1 and 2 reactors (both PWR, 826 MW). This is the first time KEPCO has petitioned for an extension of the 40-year term specified under the Law for the Regulations of Nuclear Source Material, Nuclear Fuel Material and Reactors (Nuclear Reactor Regulation Law) to 60 years. At the same time, KEPCO announced that from mid-May it would conduct a special inspection of the Mihama NPP Unit 3 reactor (PWR, 826 MW), necessary to petition for an extension of a reactor’s operating life.
While the power outputs of the five reactors being decommissioned are smaller, the three intended for extension have rather large outputs. The explanation is that even if costs are incurred in extending the reactors’ lives, these costs can be recovered if the power companies receive permission for this instead of decommissioning. In fact, however, it will probably be extremely difficult to recover the costs. Nonetheless, there is a reason for avoiding decommissioning; if these reactors were decommissioned, it would mean that not even one reactor’s operating life had been extended since the system making it possible to extend reactor lives was introduced. It can be said that no one but Japan’s electric power companies carry out private implementation of national policy in which political decisions trump business decisions.
Still, the decommissioning of the five reactors will reduce the number of nuclear reactors in Japan to 43, with a total output of 42.2 GW.
2030 Electric Power Generation Cost Estimations
A working group of the Advisory Committee for Natural Resources and Energy presented the results of projected 2030 electric generation cost estimates for each power source on April 27, and the Advisory Committee’s Subcommittee on Long-term Energy Supply-demand Outlook presented its report the next day, on April 28. Electric generation costs per kilowatt hour (kWh) were sought for model plants envisioned for each energy source, and thus capital costs, fuel costs, and operating and maintenance costs were included, and for nuclear power, the costs of additional safety measures and accident risk management, added when the new standards went into effect, were also included.
The results of the estimation for nuclear power show a lower limit of 10.1 yen/kWh, taking the possibility of increased accident risk countermeasures into account. As for the other sources, the cost of power from coal was estimated at 12.9 yen/kWh; from LNG, at 13.4 yen/kWh; from petroleum, at 28.9 to 41.6 yen/kWh; from solar, at 12.5 to 16.4 yen/kWh; from wind (land-based), at 13.9 to 21.9 yen/kWh; from geothermal, at 19.2 yen/kWh; and from conventional hydropower, at 11.0 yen/kWh, indicating superiority of nuclear power from a cost perspective. In past cost estimates, the conditions of the calculations have differed each time, but nuclear power has always come out cheapest.
Nevertheless, the above-mentioned Subcommittee on Long-term Energy Supply-demand Outlook has been trying to introduce a fixed purchase-price system such as FIT-CfD (feed in tariff contracts for difference) because of the difficulty of recovering investment costs for nuclear power facilities.
Investigation of Interior of Fukushima Daiichi Unit 1 Reactor Containment Vessel Commences
TEPCO commenced an investigation of the interior of the Unit 1 reactor containment vessel at the Fukushima Daiichi Nuclear Power Station on April 10. This is being done for the purpose of ascertaining peripheral conditions of the first floor metal grating outside the pedestal (cylindrical portion of the lower outer reactor pressure vessel) in order to get a grasp early on of conditions within each containment vessel prior to future fuel debris removal operations. The investigation was conducted using a remotely operated shape-changing robot developed by Hitachi-GE Nuclear Energy. It was announced as being able to withstand high levels of radiation, but it ceased functioning the same day after covering only about two-thirds of its expected range. Its recovery was abandoned.
The second robot, which was brought in on April 15 and 16 did not cease functioning, but the camera observing the robot’s operations malfunctioned, making it impossible to confirm its actions, and in the end, it could not be recovered either.
Even so, TEPCO claimed that it had been able to gather sufficient information, and is planning to conduct an investigation of the sub-basement of the pedestal’s exterior before the current fiscal year ends at the end of March 2016.
Ambassador Mitsuru Kitano of the Permanent Mission of Japan to the International Organizations in Vienna signed the Convention on Supplementary Compensation for Nuclear Damage (CSC) on January 15, entrusting the CSC acceptance documents to the IAEA Director General Yukiya Amano. The convention thereby went into effect on April 15. For effectuation of the convention, a Japanese domestic law was approved on November 19, 2014, and an enforcement order was approved by the cabinet on April 3, 2015, going into effect on April 8.
If an accident occurs in any other signatory nation besides Japan, Japan will contribute four billion yen. The enforcement order stipulates that in order to appropriate funding for such contributions, each of Japan’s nuclear power companies will be required to pay a general share of the money to the national government each year. If an accident occurs in Japan, the government will pay a maximum of 14 billion yen in compensation to the companies involved, in which case, the companies will pay about seven billion yen to the national government as a special assessment.
Under the CSC, suits for compensation may not be filed except through the courts of the country in which the accident has occurred. Japan was reluctant to sign the CSC at first, but after experiencing the Fukushima NPP accident and sensing the necessity to ensure jurisdiction inside Japan, it made a quick decision to hurry up and participate.
Three Methods Proposed for Removing Fuel Debris
At a meeting on decommissioning and water contamination evaluation held on April 9 in Koriyama, Fukushima Prefecture, attended by representatives of municipalities and commercial and industrial groups of that prefecture, the Nuclear Damage Compensation and Decommissioning Facilitation Corporation announced motions for technical strategic plans for decommissioning the Fukushima Daiichi NPS. Methods being strongly considered for efforts to remove fuel debris include (1) a flooding method, in which each containment vessel is filled with water, with the debris removed subsequently from above, (2) an aerial method, using water only at the bottom, where the debris is located, to remove it, and (3) another aerial method, involving removal of the debris laterally. The flooding method has problems of water leakage from the containment vessel and earthquake resistance, while problems with the aerial methods include the need for measures against the dispersal of radioactive dust. The Nuclear Damage Compensation and Decommissioning Facilitation Corporation will confirm the choice of methods in fiscal 2018.
