TENNESSECOALASHVALLEY SPILL SUMMARY

The TVA Kingston Fossil Plant coal fly ash slurry spill occurred just before 1 a.m. on Monday December 22, 2008, when an ash dike ruptured at an 84-acre (0.34km2) solid waste containment area at the Tennessee Valley Authority's Kingston Fossil Plant in Roane County, Tennessee, USA. 1.1 billion gallons (4.2 million m³) of coalfly ashslurry was released. The coal-fired power plant, located across the Clinch River from the city of Kingston, uses ponds to dewater the fly ash, a byproduct of coal combustion, which is then stored in wet form in dredge cells. The slurry (a mixture of fly ash and water) traveled across the Emory River and its Swan Pond embayment, on to the opposite shore, covering up to 300acres (1.2km2) of the surrounding land, damaging homes and flowing up and down stream in nearby waterways such as the Emory River and Clinch River (tributaries of the Tennessee River). It was the largest fly ash release in United States history.

AMOUNT OF SPILL

The TVA and Environmental Protection Agency initially estimated that the spill released 1.7 million cubic yards (1.3 million m³) of sludge, which is gray in color.[1][2] After an aerial survey, the official estimate was more than tripled to 5.4 million cubic yards (4 millionm³) on December 25, 2008.[1][3] The spill covered surrounding land with up to six feet (1.8 m) of sludge.[4] The EPA first estimated that the spill would take four to six weeks to clean up; however, Chandra Taylor, the staff attorney for the Southern Environmental Law Center, said the cleanup could take months and possibly years.[5] As of June 2009, six months following the spill, only 3% of the spill had been cleaned and is now estimated to cost between $675 and $975 million to clean, according to the TVA.[6]

The 84-acre (0.34km2) unlined aboveground ash fill, which was situated 60feet (18m) above the ash pond and 74feet (23m) above the Emory River winter level, 741feet (226m) above sea level,[7] contained a watery slurry of fly ash generated by the burning of finely ground coal at the steam power plant.[8] The fly ash, which is the consistency of face powder, is the fine particulate pollutants produced by the combustion of coal, which are collected rather than allowing them to escape into the atmosphere, then mixed with water so they can be pumped into the retaining pond.[9] Once the particulate matter settles out, it is dredged to drying cells.[9] The dredge cell was surrounded by 60-foot (18m) tall earthen walls, which had twice developed leaks since 2002.[10] Although the land surrounding the power plant is largely rural rather than residential, the spill caused a mudflow wave[11] of water and ash that covered 12 homes,[12] pushing one entirely off its foundation, rendering three uninhabitable,[3] and caused some damage to 42 residential properties.[13] It also washed out a road,[9] ruptured a major gas line,[11] obstructed a rail line, downed trees, broke a water main,[14] and destroyed power lines. Though 22 residences were evacuated,[15] nobody was reported to be injured or in need of hospitalization.[12] It was the largest coal-related slurry spill in United States history

The 1.1 billion gallons of sludge were enough to fill 1,660 Olympic-size swimming pools,[5] and the volume released was about 101 times larger than the 1989 Exxon Valdez oil spill (1.1 billion/10.9 million=100.9). On December 23, 2008, a TVA spokesman, Gil Francis Jr., stated that, at the time of the spill, the area contained about 2.6 million cubic yards (2.2 millionm³) of ash, and that two-thirds of that had been released,[4] which would later be found to cover an area of 300acres (1.2km2).[7]The New York Times noted that the amount spilled is larger than the amount stated to have been in the pond before the spill, a discrepancy the TVA was unable to explain.[3] The containment area affected was one of three; the other two stayed intact, while only the retaining wall for the 84-acre (0.34km2) solid waste containment area was affected.[16]

The confluence of the Clinch and EmoryRivers, with the Kingston Fossil Plant in the distance, five days after the spill. The white foam floating on the water consists of cenospheres, which are a component of the ash.

IMPACT

The spill killed a "tremendous" number of fish, according to the Chattanooga Times Free Press.[17]

On January 1, 2009 the first independent test results, conducted at the Environmental Toxicology and Chemistry laboratories at Appalachian State University, showed significantly elevated levels of toxic metals (including arsenic, copper, barium, cadmium, chromium, lead, mercury, nickel, and thallium) in samples of slurry and river water.[18]

Approximately 500,000 cys of ash remain in the larger Watts Bar reservoir. This remaining material is spread out over a 12 miles area and will be addressed in the next phase of the cleanup. Simultaneously, the next phase also will be closing out the failed dredge cell with an earthquake proof subsurface wall and cap

The Kingston Fossil Plant is located on a peninsula at the junction of the EmoryRiver (to the north) and Clinch River (to the south and east), just over 4miles (6.4km) upstream from the latter's mouth along the Tennessee River. Watts Bar Dam, located along the Tennessee 38miles (61km) downstream from the mouth of the Clinch, impounds a reservoir (Watts Bar Lake) that spans a 72-mile (116km) stretch of the Tennessee (to Fort Loudoun Dam), the lower 23miles (37km) of the Clinch (to Melton Hill Dam), and the lower 12miles (19km) of the Emory. The plant, originally known as the Kingston Steam Plant, was built in the early 1950s primarily to provide electricity to atomic energy installations at nearby Oak Ridge.[44]

The plant's ash pond disposal area is located immediately north of the plant along the peninsula's EmoryRiver shore. The ponds were originally created by diking off part of the lake at the Emory's confluence with Swan Pond Creek, which flows down from Harriman (just over the ridge to the northwest).[45] The disposal area consists of the main ash pond (where ash is initially dumped), which is flanked on the southeast by a stilling pond (where water from the main pond is placed to further separate it from the ash) and on the northwest by "dredge cells," where ash from the main pond is placed to further solidify. The dike breach occurred at the northwest corner of the dredge cell area, overlooking the Swan Pond Creek spillway.[46]

3 MILE ISLAND SUMMARY

The Three Mile Island accident was a partial coremeltdown in Unit 2 (a pressurized water reactor manufactured by Babcock & Wilcox) of the Three Mile Island Nuclear Generating Station in Dauphin County, Pennsylvania near Harrisburg, United States in 1979. The plant was owned and operated by General Public Utilities and the Metropolitan Edison Co. It was the most significant accident in the history of the American commercial nuclear power generating industry, resulting in the release of up to 481 PBq (13 million curies) of radioactive gases, and less than 740 GBq (20 curies) of the particularly dangerous iodine-131.[1]

The accident began at 4 a.m. on Wednesday, March 28, 1979, with failures in the non-nuclear secondary system, followed by a stuck-open pilot-operated relief valve (PORV) in the primary system, which allowed large amounts of nuclear reactor coolant to escape. The mechanical failures were compounded by the initial failure of plant operators to recognize the situation as a loss-of-coolant accident due to inadequate training and human factors, such as human-computer interaction design oversights relating to ambiguous control room indicators in the power plant's user interface. The scope and complexity of the accident became clear over the course of five days, as employees of Metropolitan Edison (Met Ed, the utility operating the plant), Pennsylvania state officials, and members of the U.S. Nuclear Regulatory Commission (NRC) tried to understand the problem, communicate the situation to the press and local community, decide whether the accident required an emergency evacuation, and ultimately end the crisis.

In the end, the reactor was brought under control, although full details of the accident were not discovered until much later, following extensive investigations by both a presidential commission and the NRC. The Kemeny Commission Report concluded that "there will either be no case of cancer or the number of cases will be so small that it will never be possible to detect them. The same conclusion applies to the other possible health effects."[2] Several epidemiological studies in the years since the accident have supported the conclusion that radiation releases from the accident had no perceptible effect on cancer incidence in residents near the plant, though these findings have been contested by one team of researchers.[3]

Public reaction to the event was probably influenced by The China Syndrome, a movie which had recently been released and which depicts an accident at a nuclear reactor.[4] Communications from officials during the initial phases of the accident were felt to be confusing.[5] The accident crystallized anti-nuclear safety concerns among activists and the general public, resulted in new regulations for the nuclear industry, and has been cited as a contributor to the decline of new reactor construction that was already underway in the 1970s

EVACUATIONS

Twenty-eight hours after the accident began William Scranton III, the lieutenant governor appeared at a news briefing to say that Metropolitan Edison, the plant's owner, had assured the state that "everything is under control".[43] Later that day, Scranton changed his statement, saying that the situation was "more complex than the company first led us to believe".[43] There were conflicting statements about radiation releases.[44] Schools were closed and residents were urged to stay indoors. Farmers were told to keep their animals under cover and on stored feed.[43][44]

Governor Dick Thornburgh, on the advice of NRC Chairman Joseph Hendrie, advised the evacuation "of pregnant women and pre-school age children ... within a five-mile radius of the Three Mile Island facility." Within days, 140,000 people had left the area.[6][43][45]

Post-TMI surveys have shown that less than 50% of the American public were satisfied with the way the accident was handled by Pennsylvania State officials and the NRC, and people surveyed were even less pleased with the utility (General Public Utilities) and the plant designer.[46

IMPACT ON NUCLEAR ENERGY

According to the IAEA, the Three Mile Island accident was a significant turning point in the global development of nuclear power.[54] From 1963–1979, the number of reactors under construction globally increased every year except 1971 and 1978. However, following the event, the number of reactors under construction in the U.S. declined every year from 1980 to 1998.[citation needed] Many similar Babcock and Wilcox reactors on order were canceled — in total, 51 American nuclear reactors were canceled from 1980–1984.[55]

The 1979 TMI accident did not, however, initiate the demise of the U.S. nuclear power industry. As a result of post-oil-shock analysis and conclusions of overcapacity, 40 planned nuclear power plants had already been canceled between 1973 and 1979. No U.S. nuclear power plant had been authorized to begin construction since the year before TMI. Nonetheless, at the time of the TMI incident, 129 nuclear power plants had been approved; of those, only 53 (which were not already operating) were completed. Federal requirements became more stringent, local opposition became more strident, and construction times were significantly lengthened to correct safety issues and design deficiencies

CLEANUP

Three Mile Island Unit 2 was too badly damaged and contaminated to resume operations; the reactor was gradually deactivated and mothballed. TMI-2 had been online only three months but now had a ruined reactor vessel and a containment building that was unsafe to walk in — it has since been permanently closed. Cleanup started in August 1979 and officially ended in December 1993, having cost around US$975 million. Initially, efforts focused on the cleanup and decontamination of the site, especially the defueling of the damaged reactor. Starting in 1985, almost 100 short tons (91t) of radioactive fuel were removed from the site. The defueling process was completed in 1990, and the damaged fuel was removed and disposed of in 1993.[citation needed] However, the contaminated cooling water that leaked into the containment building had seeped into the building's concrete, leaving the radioactive residue impractical to remove.[citation needed] In 1988, the Nuclear Regulatory Commission announced that, although it was possible to further decontaminate the Unit 2 site, the remaining radioactivity had been sufficiently contained as to pose no threat to public health and safety.

HEALTH EFFECTS

In the aftermath of the accident, investigations focused on the amount of radiation released by the accident. According to the American Nuclear Society, using the official radiation emission figures, "The average radiation dose to people living within ten miles of the plant was eight millirem, and no more than 100 millirem to any single individual. Eight millirem is about equal to a chest X-ray, and 100 millirem is about a third of the average background level of radiation received by US residents in a year."[36][56]

The Radiation and Public Health Project cited a spike in infant mortality in the downwind communities two years after the accident.[37][57] Anecdotal evidence also records effects on the region's wildlife.[37] For example, according to one anti-nuclear activist, Harvey Wasserman, the fallout caused "a plague of death and disease among the area's wild animals and farm livestock", including a sharp fall in the reproductive rate of the region's horses and cows, reflected in statistics from Pennsylvania's Department of Agriculture, though the Department denies a link with TMI.[58]

GULF OF MEXICODEAD ZONES SUMMARY

Dead zones are hypoxic (low-oxygen) areas in the world's oceans, the observed incidences of which have been increasing since oceanographers began noting them in the 1970s. These occur near inhabited coastlines, where aquatic life is most concentrated..

In March 2004, when the recently established UN Environment Programme published its first Global Environment Outlook Year Book (GEO Year Book 2003) it reported 146 dead zones in the world's oceans where marine life could not be supported due to depleted oxygen levels. Some of these were as small as a square kilometre (0.4mi²), but the largest dead zone covered 70,000 square kilometres (27,000mi²) in the Gulf of Mexico at the mouth of the Mississippi River.

The zone occurs between the inner and mid-continental shelf in the northern Gulf of Mexico, beginning at the Mississippi River delta and extending westward to the upper Texas coast.

CAUSES

The dead zone is caused by nutrient enrichment from the Mississippi River, particularly nitrogen and phosphorous. Watersheds within the MississippiRiver Basin drain much of the United States, from Montana to Pennsylvania and extending southward along the Mississippi River. Most of the nitrogen input comes from major farming states in the Mississippi RiverValley, including Minnesota, Iowa, Illinois, Wisconsin, Missouri, Tennessee, Arkansas, Mississippi, and Louisiana. Nitrogen and phosphorous enter the river through upstream runoff of fertilizers, soil erosion, animal wastes, and sewage. In a natural system, these nutrients aren't significant factors in algae growth because they are depleted in the soil by plants. However, with anthropogenically increased nitrogen and phosphorus input, algae growth is no longer limited. Consequently, algal blooms develop, the food chain is altered, and dissolved oxygen in the area is depleted. The size of the dead zone fluctuates seasonally, as it is exacerbated by farming practices. It is also affected by weather events such as flooding (more info) and hurricanes

Effects

Low oxygen levels recorded along the Gulf Coast of North America have led to reproductive problems in fish involving decreased size of reproductive organs, low egg counts and lack of spawning.

It might be expected that fish would flee this potential suffocation, but they are often quickly rendered unconscious and doomed. Slow moving bottom-dwelling creatures like clams, lobsters and oysters are unable to escape. All colonial animals are extinguished. The normal re-mineralization and recycling that occurs among benthic life-forms is stifled.

Nutrient overloading and algal blooms lead to eutrophication(link to USGS definition), which has been shown to reduce benthic(link to definition) biomass and biodiversity. Hypoxic water supports fewer organisms and has been linked to massive fish kills in the Black Sea and Gulf of Mexico.

The Gulf of Mexico is a major source area for the seafood industry. The Gulf supplies 72% of U.S. harvested shrimp, 66% of harvested oysters, and 16% of commercial fish (Potash and Phosphate Institutes of the U.S. and Canada, 1999). Consequently, if the hypoxic zone continues or worsens, fishermen and coastal state economies will be greatly impacted.