Nuclear Waste is one of the biggest disadvantages of Nuclear Energy generation apart from the dangers of nuclear reactor accidents,weapons proliferation etc.Governments around the world have mismanaged Nuclear Waste Storage leaving the solution to another day.This procrastination has led to thousands of tons of nuclear waste being stored in temporary dry cask and wet pools.This High Level Nuclear Waste poses a big danger to human health from nuclear waste effects.Nuclear Energy proponents say that Nuclear Energy is quite safe with numerous safeguards but Nuclear Waste Accidents happen with alarming regularity around the world leading to a number of Radiation Deaths.Nuclear Waste Accidents and Deaths are even reported in countries which don’t have Nuclear Power as Nuclear Waste is dumped in developing countries which have little environmental safeguards.Here is a list of some of the major nuclear waste accidents that have happened.

1. Brazil – Goiânia accident was a radioactive contamination accident that occurred at Goiânia, in the Brazilian State of Goiás. It took place after an old radiotherapy source was scavenged from an abandoned hospital site in the city. It was subsequently handled by many people, resulting in four deaths and radioactive contamination of 245 other people, 20 of who showed signs of radiation sickness and required treatment
2. India– A laboratory instrument procured by Delhi University from Canada 42 years ago and lying unused for 20 years was the source of the radiation that killed one person in Delhi and  Eight other persons involved in the scrap business were exposed to gamma radiation from radioactive cobalt-60 in 2010 after they tried to process metal junk in their scrapyard in a Delhi suburb.
3. Russia – Lake Karachay is a small lake in  westernRussia. Starting in 1951 the Soviet Union used Karachay as a dumping site for radioactive waste from Mayak, the nearby nuclear waste storage and reprocessing facility,In 1968, following a drought in the region, the wind carried radioactive dust away from the dried area of the lake, irradiating half a million people with 185 petabecquerels (5 MCi) of radiation
4. USA – Maxey Flat is a hilltop community in Kentucky.From 1963 to 1977 the Maxey Flat Low Level Radioactive Waste facility served as a dump for 832 corporations and government agencies.Approximately 4,750,000 cubic feet of Low Level USA Radioactive Waste was deposited on-site. These trenches were capped with dirt when they reached their capacity limit, but because of the heavy rainfall in the area the soil collapsed into the trenches and the trenches filled with water. It has since been referred to as the “bathtub effect.” The water that invaded the trenches became radioactive and had to be disposed of.
5. France – Tricastin Nuclear Power Plant is a collection of sites run by Areva and EDF.In July 2008, 18,000 litres of Uranium solution containing natural uranium were accidentally released.French authorities banned the use of water from the Gaffière and Lauzon for drinking and watering of crops. Swimming, water sports and fishing were also banned. This incident has been classified as Level 1 on the International Nuclear Event Scale. – source Wikipedia

Note this is just a small list of the nuclear incidents have happened.Here is a list of nuclear reactor and nuclear waste incidents that have occurred in the USA and globally.