NuclearCraft adds nine different ores to the game. They are copper, tin, lead, silver, uranium, thorium, plutonium, lithium, boron, and magnesium.
Basic Ores
Copper and tin are useful starting in early game for tools and other basic necessities and are still necessary in the later game. Lead also becomes useful during construction of machines and reactors.
Fission Ores
Uranium and Thorium are found in the over world and serve primarily as fuel for Fission reactors. Plutonium is a rare nether ore that is also extremely useful for fission. Mining Plutonium will normally yield 1 small pile of Plutonium-239, or it can be silk-touched to double the output with a crusher.
Silver is used for making RTG's, Solar panels, and empty capsules.
Fusion Ores
Lithium and Boron are both fairly useful in the fueling of Fusion reactors. In addition, boron makes a good substitute for iron armor.
Accelerator Ores
Magnesium, combined with boron to produce magnesium diboride, is used when setting up a particle accelerator.