1. Safety of Nuclear Power Reactors Final Presentation ESL 598.04 Fall 2006 Anatoliy Borodin

2. Why are Nuclear Reactors Dangerous? Radiation is a health hazard because it can damage or destroy cells within the human body. Nuclear reactors split uranium atoms to produce energy. Unstable atoms formed as a result of chain reactions emit radiation to become stable.

3. The Main Safety Concern: Possibility of an uncontrolled release of radioactive materials, leading to contamination and subsequent radiation exposure off-site. Radiation in itself can be easily stopped. Thick concrete walls of nuclear reactor buildings are a good shield against it.

4. Unfortunately, Not Only a Possibility Three Mile Island Harrisburg, Pennsylvania (1979) Chernobyl, Ukraine (1986) The more reactors we have and the longer they operate, the more accidents there will be. However, we can hope that due to accumulated experience, they won’t be significant. The two significant accidents

5. Nuclear Future Only in the United States alone, there are 104 working nuclear power plants, which generate about 20% of the nation's electrical power. The United States Department of Energy has estimated that energy use in the U.S. will increase by 20% by 2010 and 30% by 2015. The only real way to increase the amount of energy is to increase the number of nuclear power reactors. It does not seem a big deal to provide safety for a few reactors…

6. Simple and Effective Solutions A nuclear reactor cannot explode: the fuel is enriched only to 4%. An old generation reactor could melt through (China Syndrome).

7. Modern Reactors Cannot Melt Modern reactors use normal water to both cool the reactor and control the reaction. If the water leaks out or turns to steam, the reactor automatically shuts down because the presence of water is required to sustain the nuclear reaction.

8. Basic Strategy: ‘In-Depth Defense’ Although measures to avoid accidents are taken, it is assumed that accidents may still occur. Systems, therefore, are designed to combat them and to ensure that their consequences are limited to the accepted minimum. An example: The provision of leak-tight ‘barriers’ between the public and radioactive source.

9. Leak-Tight Barriers

10. My Personal Experience The allowable leakage, as specified in the Technical Specifications, is extremely small and not easy to measure. I had to create a special program to test the local and integrated containment leakage at Smolensk power plant. In my personal experience, it is very difficult to provide tightness for such a huge structure.

11. The Terrorist Factor After September 11, terrorism plays an ever-increasing role in the argument of whether nuclear power is safe or not. I believe the good guys are able to provide safety of nuclear reactors, but nothing can stop the bad guys from attacking power plants.

12. Should We Use Nuclear Energy? A popular Russian song describes the following situation: … If you do not have a dog, your neighbor will not be able to poison him; if you do not have a wife, she will never leave you for another men… The suggested solution of the problem is: Think for yourself, decide for yourself: to have or to have not. Scientists and engineers have done everything they could for people to have reliable technologies. People should decide to use or not to use them.

13. Questions? Comments? Thank You.