Plutonium is much rarer in nature than uranium and is more commonly used for bombs rather than as reactor fuel. Like uranium, it comes in various isotope forms, with plutonium 239 the most commonly used. It is mixed with the much more unstable plutonium 240 to generate power.
It's my understanding that a horse's knees close around age 2- 2 1/2. My gelding JUST turned 3. A couple days ago in fact. Will a horse's knees almost certainly be closed by that age?
About.com Horses readers have submitted the ages of the oldest horses they know, and it's clear that many horses live beyond the age of 30 with good care. The average age is 28 + 5 years. That means the average life span is 25 to 33.