Source: CNN

5 Early Lessons From Japan's Nuclear CrisisJapan is desperately racing to prevent three power reactors from melting down after last week's devastating earthquake and tsunami. This is an almost unthinkable challenge.

A similar accident happened at one reactor at Three Mile Island many years ago, but Japan's rescue effort is taking place in near-battlefield conditions on a site that is truly a no-man's-land.

The nuclear reactors at the Fukushima Daiichi and Fukushima Daini power stations were automatically shut off after the earthquake. But with external power lost and local backups damaged by the tsunami, emergency cooling systems failed to work. This has forced Japanese authorities to improvise and find other ways to keep the reactors cool, prevent pressure from building up inside the vessels holding the fuel, and prevent the reactor cores from melting significantly.

Without full knowledge of everything Japanese authorities have done since the crisis began, it is too early to properly evaluate the country's response. But even as we wait for all the facts, there are early lessons that we all can take from the nuclear crisis in Japan:

• The world should be building and operating modern nuclear reactors. Countries should build and operate nuclear reactors that use the latest and safest technology available and licensing standards need to be improved regularly. The reactors at Fukushima are 40 years old and would never be given a green light for new construction by Japanese regulators today. But China and India, two rising powers that plan to invest considerably in nuclear energy, are continuing to use 25-year-old designs for new construction. In February, the Japanese government was prepared to permit the oldest of the Fukushima reactors to operate for another 10 years after its license expired this year.
   
• Countries should not be over-reliant on nuclear energy. Last week's earthquake and another one in 2007 knocked out 15 of 17 reactors operated by Tokyo Electric Power Company on its two sites in northern Japan. If a country greatly depends on nuclear power for electricity, a major nuclear accident can trigger an electricity supply crisis. Policy makers can also face significant pressure to continue operating reactors even under unsafe conditions if the country is over-dependent on nuclear power.

• Relying on nuclear energy requires significant know-how and resources. With the threat of global warming and burgeoning energy demand around the world, nuclear power has gained favor. Dozens of countries have announced an interest in starting nuclear energy programs, and existing operators are looking to bump up their operations. But Japan's crisis underscores that generating electricity by using nuclear fission requires the best know-how, infrastructure, management experience and resources available. New plants must meet essential preconditions for safety and international cooperation should ensure that plants can withstand possible emergencies.

• Companies and countries must plan for the worst. Both earthquakes that set back Tokyo Electric were stronger than had been expected. There is a clear need to re-evaluate how seismic risk analysis is done to make sure that nuclear power plants are built to weather the worst threats they could face.

• Safety concerns must not take a back seat to energy production or prestige. For many newcomer nuclear countries -- especially those facing dire energy needs -- the temptation may be great to get new nuclear power plants on line as fast as possible. Critical aspects of nuclear programs that won't contribute to profits or generate power, such as spent fuel and waste management and emergency preparedness, cannot be neglected by governments and industry leaders aiming to achieve fast results or save money.

Given the global impact of nuclear disasters, it is in all of our best interests to ensure that nuclear operators can effectively handle unpredictable and even extreme external events that impact their installations. It will take time to fully understand the extent of the crisis in Japan, but there are steps that can be taken today that will make the world's nuclear programs safer.