I wish your analogy was useful. Look at the pictures of the storage tanks at the link, the thousands of gallons of highly contaminated water in each, the fact that the tanks have a “life span” of 5 years but tens of thousands of them would be needed to hold the contaminated water....
Fish taken off trawlers in San Diego had, according to a Wood’s Hole marine biologist, traces of Fukushima radiation. He sampled 13 fish and all 13 were contaminated...off the coast of San Diego. And that was fall of 2011. It’s been about 24 months since that sample was taken, 5 times more contamination (estimated - 5 months of continuous leaking from underground and flowing into the ocean x5 would be roughly 25months) has been dumped in the ocean and there is no plan for stopping it.
HEre’s the post about the tainted fish in San Diego.
The radioactive waste which contaminates seaweed enters the food chain (fish eaten by fish etc.) and concentrates in the larger predators which we tend to eat. There are alot of ways radiation in the ocean bad, the food web is one example.