My daughter is hardly atypical. In fact, multiple studies have shown that the vast majority of teens today are living with borderline to severe sleep deprivation. According to sleep expert Mary Carskadon, PhD, a professor of psychiatry at Brown University and director of chronobiology and sleep research at Bradley Hospital in Providence, Rhode Island, teenagers actually need more sleep than younger kids, not less. Nine and a quarter hours of sleep is what they need to be optimally alert. According to a 2010 large-scale study published in The Journal of Adolescent Health, a scant 8% of US high school students get the recommended amount of sleep. Some 23% get six hours of sleep on an average school night and 10% get only 5 hours.
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Most of the nuclear plants operating today were designed to last 25 to 40 years and with an average age of 35 years, a quarter of them in developed countries will likely be shut down by 2025. After the Fukushima meltdown, a number of countries began to consider phasing out their nuclear programs, with Germany expected to shut down its entire nuclear fleet by 2022.
The first generation of nuclear reactors was developed in the 1950s; by 2015, these had all shut down. Generation II reactors are the ones mostly in operation today. While they were designed to last only 40 years, as of 2018, the Nuclear Regulatory Agency had granted license renewals to 89 reactors for an additional 20 years. (Three of those reactors have since shut down.) A few plants have been relicensed out to 80 years. Relicensing usually involves upgrading or replacing old equipment and technology, and is less costly than constructing a brand-new reactor. 2ff7e9595c
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