Three Mile Island Nuclear Generating Station

The Three Mile Island accident was a partial nuclear meltdown of the Unit 2 reactor (TMI-2) of the Three Mile Island Nuclear Generating Station on the Susquehanna River in Londonderry Township, near the capital city of Harrisburg, Pennsylvania. The reactor accident began at 4:00 a.m. on March 28, 1979, and released radioactive gases and radioactive iodine into the environment. It is the worst accident in U.S. commercial nuclear power plant history. On the seven-point logarithmic International Nuclear Event Scale, the TMI-2 reactor accident is rated Level 5, an "Accident with Wider Consequences".The accident began with failures in the non-nuclear secondary system followed by a stuck-open pilot-operated relief valve (PORV) in the primary system that allowed large amounts of water to escape from the pressurized isolated coolant loop. The mechanical failures were compounded by the initial failure of plant operators to recognize the situation as a loss-of-coolant accident (LOCA). TMI training and operating procedures left operators and management ill-prepared for the deteriorating situation caused by the LOCA. During the accident, those inadequacies were compounded by design flaws, such as poor control design, the use of multiple, similar alarms, and a failure of the equipment to clearly indicate either the coolant-inventory level or the position of the stuck-open PORV.The accident crystallized anti-nuclear safety concerns among activists and the general public, and led to new regulations for the nuclear industry. It accelerated the decline of efforts to build new reactors.Anti-nuclear movement activists expressed worries about regional health effects from the accident. Some epidemiological studies analyzing the rate of cancer in and around the area since the accident did determine that there was a statistically significant increase in the rate of cancer, while other studies did not. Due to the nature of such studies, a causal connection linking the accident with cancer is difficult to prove.Cleanup at TMI-2 started in August 1979 and officially ended in December 1993, with a total cost of about $1 billion (equivalent to $2 billion in 2022). TMI-1 was restarted in 1985, then retired in 2019 due to operating losses. Its decommissioning is expected to be complete in 2079 at an estimated cost of $1.2 billion.

The Goldsboro Historic District is a national historic district that is located in Goldsboro in York County, Pennsylvania in the United States. It was listed on the National Register of Historic Places in 1984.

Goldsboro (formerly Goldsborough) is a borough in York County, Pennsylvania, United States. The population was 930 at the 2020 census.For historical reasons, the post office in Goldsboro is named "Etters", although there is no incorporated place known by that name, and the United States Postal Service (USPS) states that the name "Etters" is preferred over "Goldsboro" for addressing mail to ZIP code 17319. (see Etymology of the name "Etters")

Falmouth is an unincorporated community and census-designated place (CDP) in Conoy Township, Lancaster County, Pennsylvania, United States. As of the 2010 census the population was 420.

Swatara Creek (nicknamed the Swatty) is a 72-mile-long (116 km) tributary of the Susquehanna River in east-central Pennsylvania in the United States. It rises in the Appalachian Mountains in central Schuylkill County and passes through northwest Lebanon County before draining into the Susquehanna at Middletown in Dauphin County. The name "Swatara" is said to derive from a Susquehannock word, Swahadowry or Schaha-dawa, which means "where we feed on eels".

Cly is an unincorporated community in Newberry Township, York County, Pennsylvania, United States. Cly is located on Cly Road Route 262, between York Haven and Goldsboro on the Susquehanna River.

Royalton is a borough in Dauphin County, Pennsylvania, United States. As of the 2020 census the borough population was 1,134.It is part of the Harrisburg–Carlisle Metropolitan Statistical Area. It shares its ZIP code with neighboring Middletown.

Conewago Falls in Lancaster County, Pennsylvania was a historic river barrier 12 miles (19 km) below and south of Harrisburg at a wide spot (8,000 feet (2,400 m)), where the river drops 19 feet (5.8 m) in 1⁄4 mile (0.40 km) along the lower Susquehanna River along either side of Three Mile Island. The falls between the west bank and the west side of the island were inundated-by-design years ago by construction of the York Haven Dam which, when it was completed in 1904, for a time became the third largest in the world. Today the Falls hides inside the Frederic Lake reservoir along the west side of the island. The falls would often be portaged around by Native Americans with their elm bark canoes transiting between Susquehannock (and later, Iroquois and Lenape) Amerindian towns at points upriver to the Oyster beds in Chesapeake Bay or vice versa. The Falls blocked riverine navigation on the Susquehanna River, and were one of the factors preventing barge or ship water transport from Baltimore and the Chesapeake Bay.

The York Haven Dam is a low head, run-of-the river, dam and hydroelectric plant that is located on the Susquehanna River in the United States. This dam is situated 12 miles (19 km) south of Harrisburg, Pennsylvania, at the Conewago Falls impounding about 8,000 feet (2,400 m) of the river to the west side of Three Mile Island, where the river drops 19 feet (5.8 m) in 1⁄4 mile (0.40 km). When the dam was completed in 1904, it was the third largest in the world.

Swatara Ferry House, also known as "Old Fort," is a historic home located at Middletown, Dauphin County, Pennsylvania. It is a 1+1⁄2-story log building with a full stone foundation and cellar, built in two sections. It is believed to date to about 1820. It was added to the National Register of Historic Places in 1976.

Governor Stable is a notable geologic formation in northern Lancaster County, Pennsylvania. Scattered along the northern bank of a small drainage are a high number of large diabase boulders. Governor Stable is privately owned. Friends of Governor Stable administers a recreational lease on the property, allowing organization members access to the property for bouldering.

Charles and Joseph Raymond Houses consists of two historic homes located at Middletown, Dauphin County, Pennsylvania. They are two irregularly shaped brick and stone mansions in the Queen Anne style. They were built across the street from one another by two brothers, Charles and Joseph Raymond. The Charles Raymond House was built in 1891, and has a rusticated stone first story and a second story of brick. It features a variety of roof shapes and four articulated brick chimneys. The Joseph Raymond House was built in 1889, and has a rusticated stone first story and a second story of brick. It features a circular verandah and a square corner tower with an irregular pyramidal roof. It also has a large circular tower with a conical roof and a second floor balcony.It was added to the National Register of Historic Places in 1979.