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Special Bulletin
A Japanese Perspective on the International Energy Landscape (179)

July 17, 2014

Sendai Nuclear Plant Effectively Passes Safety Tests toward Restarting in Autumn
Ken Koyama, PhD
Chief Economist, Managing Director
The Institute of Energy Economics, JapanOn July 16, the Nuclear Regulation Authority approved a draft safety test report describing thefirst and second reactors of Kyushu Electric Power Co.’s Sendai nuclear power plant in Kagoshima
Prefecture as conforming to the new safety standards created in June 2013. The approval effectivelyauthorized the nuclear power plant as passing the safety tests under the new standards.
The NRA launched safety tests on nuclear plants under the new standards in July 2013.
Although the tests had initially been expected to take some six months, the tests have turned out tobe very strict and prudent and have been prolonged far more than initially expected. At present, 19reactors at 12 nuclear power plants are under safety tests based on the new standards. Among them,
the two-reactor Sendai plant was approved by the NRA in March 2014 as meeting the earthquakeand tsunami assumptions and has been given priority for intensive review. As a result, the plant
received an effective safety test pass certificate on July 16, some one year after the test launch.
The NRA has confirmed that Kyushu Electric Power has substantially enhanced anti-earthquake
and anti-tsunami measures by raising the assumed maximum earthquake strength from 540 gal to620 gal and the assumed maximum tsunami height from 4 meters to 5 meters in applications for tests
and by building a 10-meter-high protection wall, based on lessons learned from the March 2011
Fukushima Daiichi nuclear plant accident. It has also recognized the plan as conforming to theenhancement of design standards including those for all other natural disasters such as volcanic
eruptions and tornadoes. Furthermore, the NRA has reaffirmed that core and containment vessel
damage prevention measures as well as plans to address severe accidents including terrorist attacks
conform to the new standards. The safety level of the Sendai nuclear plant is “close to the highest
level in the world,” NRA Chairman Shunichi Tanaka told a press conference on July 16.
The Sendai nuclear plant has thus taken one year to acquire the effective safety test passcertificate ahead of other nuclear plants in Japan. It is now about to make full preparations forrestarting. First, the draft safety test report will be subject to public comments until August 15. Basedon these comments, the NRA will finalize the report in late August. The finalization will represent
the issuance of an official safety test pass certificate. Later, a process will be required for gaining
local residents’ agreement through briefings to them on the restart. Furthermore, the NRA will check1

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the detailed designs of equipment based on the safety test report and inspect the equipment at theplant. There will be some more procedures to be taken before the restart. With the amount of timerequired for clearing all of these procedures, the restart is widely expected to come in October orlater. Until the restart, nuclear power generation will remain nonexistent in Japan. The electricity
supply-demand balance in Japan will thus be very tight during the summer electricity demand peakthis year, as has been the case in past years.
Nevertheless, the latest NRA approval on the draft safety test report is considered a key
milestone for several reasons.
First, it is significant for the independent regulatory body to have issued an effective safety test
pass certificate for a nuclear plant, although its strict, prudent examinations have taken much moretime than initially expected. As seen in Western countries, a decision by an independent regulatory
body has great weight. With public confidence having been lost in the safety of nuclear energy andin nuclear policy through the Fukushima accident, the conclusion given as a result of the strict tests
by the NRA as an independent regulatory body may become the base for discussions on nuclear
safety not only for residents living close to nuclear plants but also for all Japanese people.
Second, the safety tests and effective pass certificate for the Sendai nuclear plant may become akey model for reference for tests under the new standards. The test process might have been anunprecedented, difficult process for both the electric power utility applying for the tests and the NRA
implementing them. As the nuclear safety problem has been a matter of national concern and a very
sensitive social issue in Japan since the Fukushima accident, there might have been difficulties withthe tests amid this maiden voyage in uncharted waters. Through the Sendai nuclear plant tests,
however, the NRA and electric power utilities may be able to find out how to rationalize andstreamline the process while maintaining the strictness of the tests. As a matter of fact, there are
great uncertainties regarding tests for other nuclear power plants while various challenges exist to besolved before the Sendai plant restarts operation. As far as the first safety tests have turned a corner,
however, attention will shift to how the first tests would influence the second and later tests.
Third, the safety test results may exert wide influence over energy policy beyond the safety of
the Sendai plant alone, even though its restart is to come this autumn or later. Specifically, the results
may influence discussions on Japan’s future energy mix. The Basic Energy Plan, approved by theCabinet in April, positioned nuclear energy as a key base-load power source, while falling short ofcoming up with a specific numerical target for nuclear energy’s share of total power generation, likethe target of 50% for 2030 as seen in the previous plan (approved by the Cabinet in June 2010).
Since nuclear and other energy projects are planned, implemented and completed over a long time, it
has been recognized in Japan that the people should share long-term numerical targets for the energy
mix. The latest Cabinet decision for the Basic Energy Plan recognized the importance of long-term
numerical targets and vowed to promptly indicate the target energy mix after discerning the progress
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in restarting nuclear plants as well as the spread of renewable energy and international discussions
on the climate change problem. In this respect, the latest development in the safety tests, as well as
the second point given above, may be of great significance. It is important to pursue thesimultaneous achievement of the three Es (energy security, environmental conservation andeconomic efficiency) and S (safety) in proceeding with discussions on the energy mix. From theviewpoint of safety, the latest NRA decision on the Sendai plant is of great significance.

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