Nuclear Compensation Convention Takes Effect
It is intended to increase the amount of compensation available in the event of a nuclear accident through public funds to be made available by the contracting parties.
The International Atomic Energy Agency announced that the Convention on Supplementary Compensation for Nuclear damage (CSC) entered into force on April 15. It was adopted Sept. 12, 1997, along with the Protocol to Amend the Vienna Convention on Civil Liability for Nuclear Damage. The CSC stipulates that at least five signatory states with a minimum of 400,000 units of installed nuclear capacity have to deposit their instrument of ratification, acceptance, or approval with the IAEA before it can take effect, and Japan did so on Jan. 15, 2015, making it take effect three months later. Argentina, Morocco, Romania, the United Arab Emirates, and the United States were the other states to do so.
The CSC is intended to increase the amount of compensation available in the event of a nuclear accident through public funds to be made available by the contracting parties on the basis of their installed nuclear capacity and UN rate of assessment and also to establish treaty relations among states that belong to the Vienna Convention on Civil Liability for Nuclear Damage, the Paris Convention on Third Party Liability in the Field of Nuclear Energy, or neither of them, while leaving intact the 1988 Joint Protocol that establishes treaty relations among states that belong to the Vienna Convention or the Paris Convention.
The 36th anniversary of the most serious nuclear accident in the United States, the partial meltdown of the Three Mile Island Unit 2 reactor near Middletown, Pa., recently passed. It occurred March 28, 1979. The Nuclear Regulatory Commission describes it as the most serious accident in the U.S. commercial nuclear power plants' operating history, "although its small radioactive releases had no detectable health effects on plant workers or the public. Its aftermath brought about sweeping changes involving emergency response planning, reactor operator training, human factors engineering, radiation protection, and many other areas of nuclear power plant operations," according to the agency, and "also caused the NRC to tighten and heighten its regulatory oversight. All of these changes significantly enhanced U.S. reactor safety."
According to NRC, a combination of equipment malfunctions, design-related problems, and human errors caused the partial meltdown and off-site releases of radioactivity.
It began about 4 a.m. on March 28 when the power plant experienced a failure in the secondary, non-nuclear section of the plant, and either a mechanical or electrical failure prevented the main feedwater pumps from sending water to the steam generators that removed heat from the reactor core. As a result, the plant's turbine-generator and then the reactor began to automatically shut down, causing pressure in the nuclear portion of the plant to rise. The plant's staff was unaware that cooling water was pouring out of a stuck-open valve, according to the NRC's summary of the accident.
"As coolant flowed from the primary system through the valve, other instruments available to reactor operators provided inadequate information. There was no instrument that showed how much water covered the core. As a result, plant staff assumed that as long as the pressurizer water level was high, the core was properly covered with water. As alarms rang and warning lights flashed, the operators did not realize that the plant was experiencing a loss-of-coolant accident. They took a series of actions that made conditions worse. The water escaping through the stuck valve reduced primary system pressure so much that the reactor coolant pumps had to be turned off to prevent dangerous vibrations. To prevent the pressurizer from filling up completely, the staff reduced how much emergency cooling water was being pumped in to the primary system. These actions starved the reactor core of coolant, causing it to overheat," the summary states.
Still, the reactor's containment building remained intact and contained almost all of the accident's radioactive material. "The NRC conducted detailed studies of the accident's radiological consequences, as did the Environmental Protection Agency, the Department of Health, Education and Welfare (now Health and Human Services), the Department of Energy, and the Commonwealth of Pennsylvania. Several independent groups also conducted studies. The approximately 2 million people around TMI-2 during the accident are estimated to have received an average radiation dose of only about 1 millirem above the usual background dose. To put this into context, exposure from a chest X-ray is about 6 millirem and the area's natural radioactive background dose is about 100-125 millirem per year for the area. The accident's maximum dose to a person at the site boundary would have been less than 100 millirem above background," the summary states. "In the months following the accident, although questions were raised about possible adverse effects from radiation on human, animal, and plant life in the TMI area, none could be directly correlated to the accident. Thousands of environmental samples of air, water, milk, vegetation, soil, and foodstuffs were collected by various government agencies monitoring the area. Very low levels of radionuclides could be attributed to releases from the accident. However, comprehensive investigations and assessments by several well respected organizations, such as Columbia University and the University of Pittsburgh, have concluded that in spite of serious damage to the reactor, the actual release had negligible effects on the physical health of individuals or the environment."
NRC also lists major changes made since the partial meltdown:
- Upgrading plant design and equipment requirements, including fire protection, piping systems, auxiliary feedwater systems, containment building isolation, reliability of pressure relief valves and electrical circuit breakers, and the ability of plants to shut down automatically
- Revamping operator training and staffing requirements
- Improved instrumentation and controls for operating the plant
- Establishing fitness-for-duty programs for plant workers to guard against alcohol or drug abuse
- Requirements for plants to immediately notify NRC of significant events and an NRC Operations Center staffed 24 hours a day
The reactor was permanently shut down and all its fuel was removed.