Can TEPCO's Kashiwazaki-Kariwa units 6 and 7 be restarted?

Nuclear Monitor Issue: 
#855
4697
13/12/2017
Yukio Yamaguchi ‒ Co-Director, Citizens Nuclear Information Center
Article

Japan's Nuclear Regulation Authority (NRA) finalized the draft of its inspection documents regarding the Application Form for Approval of Changes to Nuclear Facilities for Tokyo Electric Power Co.'s (TEPCO's) Kashiwazaki-Kariwa (KK) Nuclear Power Station on October 4, and solicited public comments for a 30-day period from October 5 to November 3. According to news reports, 904 comments were received. Since the March 11, 2011 earthquake and tsunami, when all of Japan's nuclear power plants (NPPs) were shut down, five have been restarted, all of which are pressurized water reactors (PWRs). This will be the first time for the NRA to decide on restarting a boiling water reactor (BWR), which is what TEPCO's Fukushima Daiichi NPP used. How can the NRA respond to all these views from across Japan?

History of Niigata's NPPs

Niigata is a prefecture known for its frequent earthquakes. In the past half-century alone, it experienced one large and two medium-sized earthquakes. Those were the Niigata earthquake of 1964 (magnitude M7.5), in which considerable liquefaction was noted in urban areas; the Chuetsu earthquake of 2004 (M6.8); and the Chuetsu offshore earthquake of 2007 (M6.8).

Moreover, KK was the world's first NPP to be hit directly by an earthquake. The Chuetsu offshore earthquake of 2007 resulted in leakage of radioactive substances into the environment, outbreaks of fire and uneven ground at the site, with 3,762 defects resulting.

Built straddling Kashiwazaki City and the adjacent Kariwa Village, the TEPCO-owned KK brought its Unit 1 reactor into operation in September 1985, and Unit 7, in July 1997. The combined capacity of its seven units is 8,200 MW, making it the world's largest single nuclear generating station. Units 6 and 7, in particular, are "advanced boiling water reactors" (ABWR) with capacities of 1,356 MW each and recirculation pumps contained within them.

Japan's largest electric power company TEPCO has owned and operated a total of 17 nuclear reactors in Japan (six at Fukushima Daiichi, four at Fukushima Daini and seven at KK). The electricity generated by these is all transmitted to the Greater Tokyo Area. None is supplied to either of the prefectures where it is produced.

In August 2002, however, it was revealed that TEPCO had altered data from its own inspections, concealing problems in 29 cases. It continued asserting that safety was its "top priority," but that was clearly a lie. In September 2002, Niigata Prefecture, Kashiwazaki City and Kariwa Village all rescinded their agreement for "pluthermal" (MOX) plans at the plant. The following year, in April 2003, operation of all 17 of TEPCO's nuclear reactors was halted.

Viewing TEPCO's concealment of problems as a serious issue, Niigata Prefecture established the "Technical Committee on Nuclear Power Safety Management in Niigata Prefecture" (hereinafter, the "Technical Committee") in February 2003 with the aim of increasing the prefecture's technical ability when checking KK for safety and hazards. Nevertheless, they were unable to prevent the disaster resulting from the Chuetsu offshore earthquake in July 2007. During that earthquake, Units 2, 3, 4 and 7 were running, and they shut down automatically. The other units, 1, 5 and 6, were out of operation for regular inspections.

Two subcommittees

Niigata Prefecture added six new members to the Technical Committee in March 2008 to enhance it, giving it 14 members in all. In addition, it organized two subcommittees under the Technical Committee. They were the "Subcommittee into Equipment Integrity, Earthquake Resistance Safety" (with eight members) and the "Subcommittee into Earthquake and Ground Condition" (with six members). Each subcommittee has several members that take a cautious approach to nuclear power, or are even downright critical of it ‒ a stance worthy of special mention. Indeed, this situation is without parallel.

The effect of this became more notable the more the discussions of the subcommittees proceeded. At the time, the Nuclear and Industrial Safety Agency and the NRA were Japan's regulatory institutions for nuclear energy, but while they were rather lenient toward TEPCO in their reviews, both subcommittees questioned TEPCO severely, occasionally even getting the national government to amend its decisions. It was also the prefectural government's policy to have the views of Niigata's citizens and residents reflected by the Technical Committee and its two subcommittees.

On March 11, 2011, right when the Subcommittee into Earthquake and Ground Condition was convening, wouldn't you know it, the venue underwent prolonged, major shaking. That was the M9.0 Tohoku earthquake and tsunami off Japan's Pacific coast.

Fukushima Daiichi nuclear accident verification work

Niigata's Technical Committee has turned its discussion for the time being to Fukushima nuclear accident verification work. It has augmented its membership and continues these discussions even now. For safe management of KK, it decided that what needed highest priority was clarifying the causes and results of the Fukushima nuclear accident. The four committees investigating the accident, from the Diet, the national government, TEPCO and private citizens, submitted their own respective reports, wrapping up their investigations, but Niigata Prefecture was not satisfied with that, and has been trying to clarify all aspects of the Fukushima nuclear accident.

The two subcommittees are taking a temporary break from their discussions because the Technical Committee has put forward six topics and divided its members into groups of a few people that are continuing to discuss these. The six topics are (1) the effects of seismic motion on important equipment, (2) critical decisions made, such as to inject seawater, (3) TEPCO's earthquake-response management, (4) the state of information sharing on issues such as the meltdowns, (5) work under high radiation conditions, and (6) severe accident countermeasures. Six and a half years after the earthquake, these discussions are finally shedding light on the course of events that delayed public admission of the meltdowns. The discussion of topic (1) has come to a climax. Facts are being brought to light about damage that the enormous tsunami fails to explain.

Newly elected Governor Yoneyama's policies

Ryuichi Yoneyama became Niigata's newest governor in October 2016, replacing Gov. Izumida, who had served three consecutive terms. Gov. Yoneyama is continuing his predecessor's policies. He says: "While verification of the Fukushima accident is still incomplete, we will not even begin to discuss restarting the Kashiwazaki-Kariwa Nuclear Power Station." Furthermore, he says verification work for the Fukushima nuclear accident will take another three to four years to complete. What this means is that even if the NRA gives the go-ahead for restarting the plant, Niigata Prefecture, as the locality of the nuclear power plant, will conduct its own deliberations independently of the national government and draw its own conclusions.

In addition, Gov. Yoneyama has conferred the status of "Verification Committee" upon the Technical Committee (which currently has 15 members), whose duty it will be to clarify the causes of the accident. He has also established two new verification committees. They are the "Committee to Consider the Effects from Nuclear Accidents on Health and Livelihood of a Nuclear Power Plant Accident" (five members in the subcommittee on health and four in the subcommittee on livelihood) and the "Committee to Consider Evacuation Methods in Nuclear Disasters" (nine members). To oversee all three of the verification committees, a "Verification Supervisory Committee" is to be formed.

While the committee system which has been set up is to be highly commended, it reflects only the view of experts. One wonders what kind of input Niigata's citizens and residents will be given and how their proactive views and arguments can also be incorporated. I think that is an important question for the future.

Reprinted from: Citizens Nuclear Information Center, Nov./Dec. 2017, Nuke Info Tokyo No.181, www.cnic.jp/english/?p=4016