Been reading up on Velikovsky again? There has been no global flood during humanity's time here, the signs it would have left on the planet's surface simply aren't present. Certainly there have been localized disastrous floods, but they're not synchronized into a single global event, they're scattered throughout geological time.
A Seyfert galaxy is one with an unusually active core that generates intense radiation across a broad spectrum. A few percent of the galaxies we can see are classified as Seyferts. Our galaxy is not currently a Seyfert, and there's no evidence that it has been recently, Seyfert status appears to be a stage early in the history of a galaxy when a black hole at the core is eating up all the gas and dust and stars nearby. It may also be a pulsed stage that comes and goes several times as a galaxy evolves, but if the core of our galaxy went Seyfert around 10,000 years ago, I think it probably still would be. Major cosmological events like that rarely happen on so short a time scale. I've seen calculations that suggest a Seyfert core in our galaxy would increase the radiation flux earth receives by about 2%, which certainly would be enough to affect weather patterns, but not on the scale of a global flood.