Twenty Billion (minimum) to be wasted

The UK is to spend 20 billion to update their Trident Submarine nuclear threat.
What a waste of money.
We should not be spending more money on something we will never use. It had a purpose once but it does not now.
We should set an example to all the other countries who have nuclear weapons and either a) scrap them now or b) keep them but only until they are past their lifetime.
We do not need nuclear weapons.