With the new tech, that is mostly true, the 70s tech is like the first of any tech: unwieldy, hard to control and very inefficient in both production and retirement.
Compare the first x-ray machine to a modern PET-scanner. The former caused cancer in fetuses and caused radiation poisoning through walls, the latter is a clean cellular resolution scanner that can be serviced and recycled as well as most anything.
Modern nuclear plants take about 1 Mt of fuel per ton of waste, and energy production is about 70-90% effective. Modern systems also dispose about 80-90 % of spent fuel at decay times that leave only a percent of radiation every 20 years.
Nuclear is however indeed a dead end, with current exponentially increasing energy needs we probably only have 150 years of Uranium before we need to figure out an alternative. At current energy levels, we have about 550 years.
150 years of very low pollution, stable energy is however a better, cleaner, cheaper and safer energy source than fossil oil has been throughout human history, and safer than current wind, solar and hydroelectric power.