Japan's general public opinion, as reported by mass media, seems to be demanding departure from the use of nuclear energy.The anti-nuclear sentiment has engulfed the nation like a tsunami.Talking about the editorial desk’s desire of “rebuilding nuclear safety” would be met with scornful smiles.Yet, as the situation surrounding the accident is starting to settle down, international views are beginning to change.

The British newspaper, the Guardian, ran a story titled "Why Fukushima made me stop worrying and love nuclear power" in its March 21 edition, in which the journalist said, despite the natural disaster that claimed the lives of tens of thousands of people, "no one has yet received a lethal dose of radiation".This article leads the calm public opinion now emerging in Europe and the U.S. after the storm.Historically speaking, Britain has been a nation of reason.

Over a hundred years ago, on the day of the breakout of the Sino-Japanese War, the Japanese protected cruiser Naniwa sank a British merchant vessel which was transporting military troops of Qing.The incident enraged the general public in the British Empire, which caused serious concerns to the Meiji government.However, the Times of London calmed public opinion with an editorial stating in light of international law that the blame should be directed at the merchant vessel carrying the troops of a warring nation, rather than Japan.This has eventually led to the Anglo-Japanese Alliance.Japanese mass media lacks this calm rationality.

Immediately after the Space Shuttle Challenger Disaster, President Ronald Reagan went on television saying, "A tragedy has occurred. But the Challenger crew was pulling us into the future, and we'll continue to follow them", and encouraged the continuation of the space program.After the nuclear accident at Three Mile Island, the U.S. government kept other nuclear plants operating.Yet, it was the Japanese government in bewilderment that suspended the operation of its PWR nuclear plants.This time, the nuclear power plants cannot resume their operation once they shut down.The difference between the approaches of the two countries lies in the different understanding, attitude and determination toward the development of science and technology.

The issue of energy was, indeed, one of the direct causes of the Pacific War.Nuclear power generation was the only energy with a long-term outlook available to Japan, a defeated nation, and is now a state technology that has been evolved over the last 50 years.The outcome of our predecessors' collective will and efforts has easily been put in jeopardy as a result of a single accident.The government seems too busy formulating countermeasures for radiation contamination, and has abandoned core state duties such as defense, economy and diplomacy.This has caused the deterioration of national power and invited contempt from other countries.
Before talking about rebuilding nuclear safety, we must urgently rebuild our national philosophy and public mentality.


1. Natural Phenomena and Social Canons at Root of Accident
An unbiased observation of the series of events that led to the accident shows you the cause and the lessons we should learn from it.On March 11, a powerful earthquake measuring 9 on the moment magnitude scale caused seismic ground motions greater than design-basis motions.All off-site power went down, causing a blackout across the entire Tohoku region on the Pacific side.The Fukushima Daiichi Nuclear Power Station, in such region, was successful in emergency shutdown and went into the cooling stage using emergency power supplies.Everything went as designed to achieve a safe shutdown.

Then, enormous tsunami waves struck the site.Emergency power supplies and station power distribution facilities were submerged in water, rendering most of the power station's equipment inoperable.Yet, some non-electrical safety facilities survived.Decay heat from the reactor core was used to generate steam and drive pumps to continue cooling the reactors.

The cooling operation was sustained for approximately 3 days at Unit 2 and 1.5 days at Unit 3.The fact that the timing of explosions varied between reactor units, was proof that safety facilities were active, delivering greater effects than anticipated.However, power supplies were not restored until ten days later.This is something to examine and reflect upon.

Safety facilities are designed on the assumption that power be restored in 8 hours.After either the decrease of decay heat or the depletion of the control power supplies exhausted the ability to keep safety equipment running, nuclear fuel at the reactor core melted eventually causing a hydrogen explosion.It is generally the case that the shortage of supplies leads to defeat.In the last world war, Japan's island defense units were crushed one after another at Attu, Saipan and Iwo Jima without additional supplies.It was the same for this accident.If power had been restored as designed, Unit 2 and Unit 3 would not have experienced the accident, although there is room for debate on situations at Unit 1.

Let me add that the current regulatory guide for safety design is common rules applied almost universally.The same estimated time setting is used for power restoration in Japan and the United States.Even though a review of the safety guidelines are asked of, IAEA's regulatory guide for safety design is not expected to undergo significant changes, judging from how matters on safety design were considered and processed at TMI and Chernobyl.In fact, since this accident was induced by a natural disaster, international discussions are expected to shift their focus to disaster prevention, which is to be discussed later.

In summary, the cause of the accident was the arrival of tsunami waves much greater than the design-basis level, while the accident evolved into a disaster due to the delay in restoring power supplies.The primary causes were the natural phenomena and socially-accepted notions, hidden behind our experiences and perception of common sense.The power station's established safety design in question was not at fault.


2. Disaster Readiness
The regulatory guide for safety design stipulates that past records be examined to design facilities to withstand the impact and effect of tsunamis and other natural phenomena.Aside from those phenomena, in the case of earthquakes, there are additional requirements for the strength design and the seismic motion analysis that corresponds to the levels of safety importance.In other words, additional engineering considerations are required, which has proved to be effective.

The Chuetsu-Oki and Great East Japan Earthquakes caused seismic ground motions greater than those defined as design basis, but nuclear power stations withstood their impact.They did not fail, indeed.Their structural weaknesses were reinforced under seismic design to give the power stations sufficient seismic margins.The key to solutions could be found in applying engineering knowledge to build power stations resilient against natural disasters.

Almost 40 years ago, at a meeting of safety assessment, I was told that, at open coastlines such as those facing the Pacific, tsunamis should be perceived as nothing more than tidal waves, measuring up to 6 meters at maximum.We now know that this perception was wrong, but that was the best judgment of geophysicists and other top authorities in those days.

There was, in fact, an opportunity to rectify this misjudgment.Recent sediment analysis and hydro-dynamic simulation studies examined the Jogan Tsunami that struck the Tohoku region with extremely high waves in 896.Such findings were then conveyed to the Nuclear and Industrial Safety Agency in 2009.It was discussed, but no actions were seemed to have been taken.Some say this negligence is a man-made tragedy.

On this planet, massive natural disasters are rare, happening only once every thousand years.The data of natural disasters is a collection of figures specific to disasters with a low level of reliability, rather than a large number of more universal figures that engineers are used to handling.Relying on such numerical data as safety design conditions was what led to our mistakes.

To correct this mistake, we must change our attitude of passively accepting a judgment given by the authorities. Instead of building solely on the authoritative judgment that tsunami waves would be no bigger than 6 meters, for example, we must take a similar approach to seismic design, studying natural phenomena in general, applying engineering considerations to the findings and strengthening any weakness.In a related manner, we would be repeating the same mistake by answering the demand of a new seawall be built to protect the Hamaoka Nuclear Power Station.Such a demand is illogical and unnecessary.

Incidentally, this is not the end of countermeasures for natural disasters.It is necessary to establish disaster prevention preparedness based on stress test results, with the assumption of disasters “beyond design-basis levels”.The installation of permanent facilities is not necessarily the answer to disaster preparedness, considering the difficulty in predicting not only the frequency of disasters but also their intensity.In fact, it could do with organizing simplified facilities that can manually address emergency measures, portable reserves and supplies for shared use, and relevant trainings on personnel.

A good example is the fact that the Fukushima accident calmed down following the immediate installation of temporary power supplies.Measures for disaster preparedness cannot be applied uniformly across the nation, considering local characteristics.Yet, some measures should be developed for joint implementation globally.It is desirable to develop a basic framework with international cooperation in vision.


3. Diversified Emergency Power Supplies
The indefinite loss of off-site power is not assumed in safety design.This is because nuclear power generation without electricity is like fish without water.Nuclear safety can be achieved only after it grounds itself on a modern technical platform.With multiple high-voltage transmission lines installed, Japan only suffers blackout for no more than one second in most cases, giving a track record of quick power restoration.Nuclear safety is built on modern technology, a notion shared globally.

Past records and experiences, which can be described as social common sense, failed in the recent accident.The blackout lasted for ten days. There is no denying the resulting tsunami of an unusual scale, but how should the power restoration time, the foundation, be perceived? Some are seeking a review on the adequacy of the regulatory guide for safety design which allows the loss of power for a short time.

This seems a difficult task, but the solution is surprisingly simple.Emergency power supplies of multiple types should be deployed appropriately to handle any disaster scenario.There is no other way of supplementing required power.

The regulatory guide for safety design demand multiplicity and diversity of emergency power supplies.However, in the 1970s, when the Fukushima power station was built, water-cooled diesel engines were the only emergency generators with high reliability.Consequently, diversity could not be achieved in those days.

However, technology is advancing rapidly.Today, multiple types of highly reliable generators are available, including air-cooled diesel generators and gas turbines.The jumbo jet aircraft, developed in the 1960s, carried four engines, whereas the Boeing 777 of now has only two.There were, in fact, two opportunities to put the diversity of power sources in practice.

The first opportunity came in around 2002, when the U.S. Nuclear Regulatory Commission (NRC) ordered all power stations in the United States to adopt diversity in emergency power supplies in response to the 9.11 terrorist attacks.South Korea, Taiwan and many other countries adopted similar actions after learning of this advisory.However, the information was treated as terrorism-related confidentiality in Japan, and was not released publicly.

The other opportunity arose when the aforementioned finding was made concerning the Jogan Tsunami.Analysis by the Japan Nuclear Energy Safety Organization (JNES) had apparently predicted that a similar tsunami would cause station black out and subsequent meltdown of reactor fuel rods.It is regrettable that such opportunities were not seized.Putting such insight into practice may have prevented the accident at Fukushima.

As a matter of fact, Unit 5 and Unit 6 of the same Fukushima power station escaped disasters because a single air-cooled emergency generator was activated.In the United States in April of this year, the Browns Ferry Nuclear Power Plant in Alabama experienced loss of external power for four days following a tornado in the area, but accidents were averted due to the activation of emergency power, reinforced in the said anti-terrorism action.

There are other criticisms over hydrogen explosions at Fukushima and the power station's response to them, but I will leave it for another occasion.


4. Penetrating Insight into Safety Needed
In recent years, there was a general complacency about safety within the nuclear energy industry.Ironically, this trend emerged prominently following the establishment of the Nuclear and Industrial Safety Agency.The Agency's excessive emphasis on quality assurance imposed massive paperwork on plants' staff, preventing them from attending on-site duties.This diminished on-site safety awareness at power stations.

Biased belief that quality assurance equals nuclear safety emerged at government offices.Self-righteous implementation of regulations diminished the availability of engineers capable of identifying the status of reactor core at the time of an accident or perceiving other elements of nuclear safety public and private sectors. Serious repercussions were evident if you remember how the government and electric power companies failed to identify core meltdown for two long months and issued erroneous media releases and random descriptions of events in the days immediately following the accident.

The Shimane Nuclear Power Station of Chugoku Electric Power Company was forced to suspend its operation after the Agency announced that the power station has over 500 quality assurance nonconformities, even though none of them were related to safety.Such abnormal regulation-centric nuclear administration, which amounts to the abuse of power, was the underlying cause of this accident.

Delicate work in the presence of radiation is the essence of nuclear technology.Yet today, desktop engineers who rely on computer results while having no on-site experience are exerting influence in public and private sectors. Situations are much worse in the academic sector, creating the origin of remote causes of accidents.Such impediments to nuclear safety must be rectified, or Japan's nuclear industry might turn into a third-generation merchant, portrayed in a satirical Senryu poem, who has to sell the business after neglecting it while spending too much time on a fancy hobby.


5. Fulfilling Japan’s Duty to the World
Finally, let me make one suggestion for a breakthrough.How about turning the Fukushima power station site into a venue for international radiation research until decommissioning work commences?The area can be set up as a special radiation zone for conducting various studies covering a comprehensive range of subjects with no restrictions as long as the research does not affect the outside world.Why not make the site available to researchers around the world, even though there could be some limitations?

Researchers can stay at the site to gain a first-hand insight into the accident, and spread the word about the power station's actual situation to their respective countries in their native language.This could alleviate overseas criticism towards Japan about lack of information, and help communicate necessary information about the disaster, eventually restoring other countries' trust in Japan on a psychological level.It would be an ideal way for Japan to fulfill its responsibility and obligations as a nation that has led the drive for nuclear energy along with the United States and France.

Needless to say, the establishment of such a research venue would contribute to mitigating the effects of nuclear disasters, promoting understanding on radiation protection, and facilitating trainings for work performed under radiation.Envision not only a 'high radiation research lab' but also use it for retraining desktop engineers.