All these extra methods of preserving water adds cost, to a technology where paid off plants are struggling. Let alone ruinously expensive new builds.
They don't materially affect the cost of a nuclear power plant. Cooling towers or evaporating ponds are not expensive. Coal and gas power plants also use them.
You just can't easily retrofit them onto an _existing_ power plant.
At least these installations don't need to deal with radioactive material directly, so they will have the same financial infact as similar improvements to, say, coal-fired power plants.