The Pacific Northridge National Laboratory was able to extract uranium from seawater at $200/lb, as per the linked article. This is an order of magnitude greater than the price of conventional extraction, so it makes no sense for commercial providers. But uranium extraction amounts to a negligible fraction of the cost of nuclear power, so even if economies of scale fail to bring the price down this amounts a fraction of a cent increase in the cost per KWh. Not to mention there's at least hundreds of years worth - thousand of years if we use reprocessing - worth of conventionally accessible uranium.

There are none. Only one or two lab bench scale reactors at universities.