1. It caps the liability for an incident at a single reactor. It goes up with inflation and I believe it's currently $500 million;
2. It establishes an industry-wide secondary self-insurance fund for broader incidents and caps liability. I believe the current theoretical value is $15-20 billion; and
3. In the event of a wider incident, the per-reactor liability cap is lower than (1). I believe it's $150 million.
So who pays if an incident exceeds these caps? The government does. These are either entirely or largely privately owned. Why exactly are we subsidizing private providers this way while enjoying none of the profits?
Now go and look at the cleanup costs of either Chernobyl or Fukushima. The latter is going to take decades, possibly a century, and the costs are in the hundreds of billions of dollars. Chernobyl is probably higher.
Yet these get hand-waved away by nuclear advocates despite there being 2 major events when fewer than 700 nuclear plants have been built (and I believe that includes non-power plants).