Why don't we send nuclear waste to the center of the earth?

This is actually a valid suggestion but only applicable to transuranic elements which by the way are the longest half life part of the waste. The low atomic number radioactive elements like iodine and cesium isotopes have too high a vapor pressure to be injected into Earth. They are volatile and will come out as gases. read more

We have no access to The Center of the Earth. However we can sink our nuclear waste in the Marianna Trench which is under 7 miles of water. Plenty of water to absorb neutrons and ionizing radiation. Wrap the waste in borated glass containers and dump away. Heave ho. Out of sight out of mind, or as the Chinese say - Blind Idiot. read more

We've only sent one space probe near the Sun, when NASA and ESA launched Ulysses in 1990. To get to the Sun, they sent the probe to Jupiter in order to slingshot it into a few polar flybys of the Sun, each spaced out by about six years. read more