[Fido969]

Is that going to leak into the ocean and radiate the Pacific Ocean and spread over the globe..

Happily, distance is in our favor. Concentration decreases by about the square of the distance, so by the time it any radiation gets to us, unless it's concentrated in a plume, it won't have any real effect, aside from statistical. Even Chernobyl was merely concentated to some areas in eastern Europe.

But it was very tough on the people who were affected.

[BenKenobi]

Even in Chernobyl, Kiev at 50 miles from the plant was entirely unaffected.

[kroll]

Concentration decreases by about the square of the distance,

Indeed it would, if they were no currents, and no continents/land-masses, no salinity and heat in the ocean. Unfortunately or fortunately (depending on what the currents do) the movement of radioactive substances can be more, or Less organized (i.e. More diffusive). In this case it is almost certainly More diffusive because of the powerful Kuroshio current (the japanese equivalent of the Gulf-stream). It would get pretty well-mixed by the time it flows towards the alaska current and makes it into the californian current. It still sucks for the locals though...