No, more like "time to learn how to do arithmetic", such as how little something like Fukushima amounts to when diluted in a volume the size of the Pacific Ocean.
The Soviets used to dump scrap ship reactors into the Arctic Ocean whole. Many of them, and over a long period of time.
I don't have an exact number for this reactor, but several sources indicate that nuclear reactors have something of the order of 100 tonnes of uranium in them (there are also fission products, of course, but those are in much smaller quantities).
The oceans have about 4.5 billion metric tons of uranium in them from natural sources.
It should be clear that even if you ground up the entire Fukushima reactor into a fine powder and dumped it straight into the ocean, it wouldn't make the slightest difference.
Can a reactor disaster pollute the local region, including ground water? Certainly.
Can a reactor disaster make a significant difference in something the volume of the Pacific Ocean? No, it's sheer nonsense.
The Soviets used to dump scrap ship reactors into the Arctic Ocean whole. Many of them, and over a long period of time.