James Tulenko: Safer than Daichi?


Published: Sunday, January 8, 2012 at 6:01 a.m.
Last Modified: Wednesday, January 4, 2012 at 11:01 p.m.

The primary question that remains after the incident at Fukushima, Daichi in Japan, where four of the six reactors were severely damaged and a large quantity of radioactivity was released, is what is the level of safety of U.S. nuclear plants?

While safety was always an important issue in the development of nuclear power, it came into stark focus after the accident at Three Mile Island, in Pennsylvania, in 1979. No one was injured by the radiation at that plant, including plant workers, however the core was destroyed and it took years to eventually decontaminate and decommission the reactor.

This was the proverbial wake up call for the nuclear industry in realizing that poor safety performance at one plant could have a serious impact across the entire nuclear power enterprise. The result was that not only did the Nuclear Regulatory Commission (NRC) mobilize to make sure such an event never happened again, the nuclear electric utilities did as well, creating the Institute of Nuclear Power Operations (INPO) by which the nuclear industry polices all plants to ensure their safe operation.

What emerged from the period after the TMI accident was a group of organizations that created and imposed a set of standards of operation to which all nuclear plants needed to adhere. Unlike the requirements from the NRC, these were not legally binding, but there was unanimous understanding that this is what was needed to successfully and safely operate their nuclear plants.

INPO, which came into being in 1981, sets performance standards and provides guidelines for operating nuclear plants. Out of that organization arose the National Academy for Nuclear Training, which accredits the training programs at nuclear utilities, such as Florida Power and Light, that train nuclear plant operators and operations supervisors. The author of this report spent two terms on this board accrediting the utility training programs.

It was not a rubber stamp approval, the board made sure that the U.S. utilities maintained the highest standards of safety in their training programs. By all measures, the intense attention to safety at U.S. nuclear plants has paid off. Since TMI there has not been an incident that came close to causing major damage to a reactor, and certainly not causing a threat to the public.

This safe record has been the result of the combined effort of the NRC and INPO to identify weaknesses in nuclear plant hardware as well as how nuclear plants were operated. Systems were revised or replaced to both make safety more automatic and, most importantly, very clearly tell the reactor operators what was going on in the plant.

This failure to understand what was happening at the plant was the real cause of the TMI accident. Also, always backing up the operational safety systems is the concept of defense-in-depth. The assumption is that one or more safety systems could fail and that backup systems would kick in, with ultimately multiple barriers to prevent the release of radioactive material providing the last bastion.

What we see today in nuclear plant safety statistics is a picture of an industry operating at a very high level. A key measure of safety is the number of annual significant events that occur; these are events that down the road could lead to safety problems. From peaks in the 1980s, those numbers fell steadily through the 1990s to a currently very low frequency, less than one-tenth of what they had been.

Another telling statistic is the capacity factor for U.S. plants, which is the percent of full power operation over a year. Today, U.S. nuclear plants consistently operate near 90 percent, which is unprecedented for any other power sources including coal, oil and gas.

The message is that running plants safely also means running them efficiently.

At Fukushima Daichi it took an earthquake of totally unexpected magnitude and a tsunami that nearly topped the reactor buildings to cause the serious accidents that occurred. While no member of the public was harmed by radiation, it is something we need to take seriously as we rereview nuclear plant safety in the U.S.

But to keep things in perspective, the events at the reactors in Japan were caused by a natural disaster that also took the lives of perhaps 20,000 Japanese. While it should not be a source of comfort, that reality needs to be understood as we plan for the future of nuclear power in Florida and the rest of the country.

James Tulenko is director of the Florida Laboratory for Development of Advanced Nuclear Fuels and Materials at the University of Florida.

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