Nuclear energy not likely to stop but can be safer after Japan disaster, experts say

LOS ANGELES, March 8（Xinhua）-- Following the nuclear disaster in Japan after the tsunami in March 2011, the United States and other countries have reviewed their nuclear energy policies and more strict and safer measures have been taken, but it is unlikely nuclear energy will be stopped.

Andrew C. Klein, professor of nuclear engineering and radiation health physics at Oregon State University, told Xinhua in an interview this week that the lesson the world has learned is to make nuclear energy safer but not to avoid it.

"A number of countries like Germany and Austria have decided not to continue their nuclear programs. The Japanese have talked about not to continue but they will continue anyway because they have very few options for large scale electricity generations and the U.S. will continue to build a couple of new reactors in Southeast," said the nuclear expert.

Klein's research interests include nuclear energy policy, space nuclear systems design, transient analysis of nuclear power systems, radiation shielding, nuclear nonproliferation, safeguards and security, and fusion energy systems design.

He admitted that the nuclear disaster in Japan has slowed down some of the nuclear expansions that have been talked about.

"The U.S. has slowed down a little bit, some have stopped, but others are continuing. It is different country by country," he said.

"The kinds of lessons we have learned of the disaster in Japan are related to the operations of the systems and the availability of the electricity to provide the power. I know the utilities in the U.S. are working hard to address this issue. But it is important to remember that if there had been a 45-meter sea wall, this would not have happened," said the expert.

"But remember the 20,000 people died of the tsunami and earthquake, not the nuclear disaster," Klein added.

He stressed that the disaster that happened in Japan is extraordinary because of the nature of the natural event.

Asked on what lessons the U.S. has learned from the disaster, Klein said："As far as I know the plants in California have been looked at and have been determined that they have done the protective measures necessary. But they will continue to keep looking at in case of something new comes up."

Asked whether this disaster could be avoided, Klein said："I don' t think we could avoid disasters such as the tsunami and earthquake, but we can avoid the nuclear disasters because every nuclear plant when it was built was looked at those issues."

He said it will be site dependent and will be country dependent upon where they choose to go ahead.

Asked whether nuclear energy will be replaced by other measures to electricity, Klein said："The U.S. has got 20 percent of electricity from nuclear, and if we believe the greenhouse gas emission should be reduced, the only way we can change that, and the major way to eliminate both natural gas and coal is to get large amount of electricity from nuclear."

But Klein said it is wise to have a diverse set of options for electricity generations.

"I think nuclear energy has to be important and the other technology is important to continue to develop. The problem is the sun does not shine all the time and the wind does not blow all the time when people want electricity," he added.

"I think nuclear electricity is still a valuable piece of energy, and turning off the 104 nuclear plants in the U.S. will be a huge mistake. I think new plants will continue to be developed," said Klein.

"Four plants have been developed in Southeast U.S. It will be new designs and should be much safer than the other designs that are 45 or 50 years old. So the lesson we have learned is to keep nuclear energy safe but not to avoid it," said Klein.

Yong-Gang Li, professor of earth science research at University of Southern California, told Xinhua in an interview that the nuclear disaster caused by the tsunami is a serious lesson to Japan and other countries in the world.

In his opinion, one of the lessons is that people had underestimated the seriousness of the earthquake. The Fukushima Daiichi nuclear power plant was designed to survive 8-magnitude quake, but the actual quake was 9-magnitude.

He said the Oceanside nuclear power plant in Southern California was designed to resist 7.5-magnitude quake, but if an 8-agnitude quake takes place, there will be another disaster.

According to Professor Li, scientists are considering an option to raise the sea wall, but it is hard to build, and it is difficult to determine how long the sea wall should be.

However, according to Li, there are ways to have water supplied for the cooling system in case of a power shortage to avoid a meltdown and those measures will be taken by most of the nuclear power plants.

He said the fourth generation of nuclear power plant is much safer, so the four new plants to be built in the U.S. will have much sophisticated technology, but in his opinion, it is unlikely the U.S. will replace all the old reactors with new technology.

"I think the United States will slow down in building new nuclear plants, but will not completely give up nuclear energy. The U.S. is actively developing new energy and will gradually reduce the dependence on nuclear energy with new energy," said Li.

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U.S.experts talk about future disaster prevention one year after Japanese earthquake

新华网

LOS ANGELES, March 9（Xinhua）-- One year after Japan's devastating earthquake, U.S. experts summed up the lessons learned from the tragedy and offered their suggestions on reducing damages by future disasters.

Yong-Gang Li, professor of earth science research at University of Southern California, said the Japanese government and communities had all underestimated the massiveness of the earthquake before it took place.

Japan had been preparing itself for massive earthquakes, but not for a 9-magnitude one, Li said, as scientists only expected a possible 8-magnitude quake. So when the 9-magnitude earthquake struck the island, people were caught off guard.

According to the earth science expert, the chance to have a 9-magnitude earthquake in Japan is something once in a thousand years, so most of the buildings and nuclear power plants in Japan were only built to resist a quake up to 8 magnitude.

They also underestimated the possibility of a devastating tsunami caused by the quake, said Li.

He said Japan's tsunami warning only predicted 15-meter waves, while the waves turned out to be 30-meter high, twice as strong as estimated.

Li said scientists are now studying how such a strong tsunami would take place, and Japan is going to drill deep into the seabed to the earthquake center to find out the cause of the earthquake, with support from the United States and other countries.

Li said that for now, it is impossible to predict accurately when an earthquake would happen, but scientists can provide both long and short term warnings based on history records and the earth structure.

He said many people in California are now worried that a big earthquake might come soon, but in his opinion the chance is slim in the near future.

Based on research, the frequency for Northern California, including San Francisco, to have an 8-magnitude quake is once in 200 to 250 years, while the last time a major earthquake hit the place was in 1906, just a little bit over 100 years.

However, the danger to have an 8-magnitude earthquake in Southern California, including Los Angeles, is increasing, said Li. A major earthquake could hit the area anytime from now on, he added.

Li explained that the last devastating earthquake hitting Southern California was in 1695, far over the 250-year rule, so it is important for people in Southern California to be fully prepared for a major earthquake.

But the expert said Southern California was unlikely to experience devastating tsunami like what happened in Japan last March, as their earth structures are different and the movement of fault in Southern California is horizontal, not vertical, which usually produces strong tsunami.

Li said it is important to have the government coordinate research institutes, communities and local people in the education and prevention training against earthquakes.

During the Japanese earthquake, a tsunami warning was issued 3 to 4 minutes after the earthquake, but to have people moved to a safer place is more important, so education and prevention training is crucial, Li said.

He said the government should select and build emergency shelters at safer places before the earthquake, and residents should be trained to evacuate in time and order.

Also, it is important to make sure that buildings and structures in the earthquake frequent areas have the capability to resist major earthquakes, Li said.

Hiroo Kanamori, professor in physics of earthquakes at California Institute of Technology, told Xinhua that there is no way to predict earthquakes, but it is possible to provide tsunami warnings soon after an earthquake.

In the case of Japan, it took about 30 minutes for the tsunami to reach the shore and cause damages to properties, and Japan can now issue tsunami warnings three minutes after an earthquake, which means there are 27 minutes for people to leave, and that 27 minutes are life saving.

He said Japan now already has had a tsunami warning system, but the system needs to be more accurate. That requires new technology and a whole network which demands more manpower, software and hardware.

Only in this way can the government provide more accurate tsunami warnings and enable residents to move to safer places in a shorter period of time, Kanamori said.

Disaster prevention training is very important, he said. The Japanese government has already learned the lesson and realized the importance to make residents more prepared, he added.

Kanamori said disasters usually take place unexpectedly, and there is no experience to rely on. So to have everyone prepared before the disaster is very crucial.