Nope. It would just explode the unit and throw the fuel inside everywhere. You have to ramp things down smoothly as reactors are basically atom bombs in super slow motion so they can be kept in a feedback loop.
Normally some plants can take days or even weeks to fully shutdown and that is with full power, full staff, no earthquake/tsunami damage.
Right now they are dealing with damaged systems operating way outside any normal environment with limited resources.
The seawater and boric acid is a last ditch effort to avoid some local, albeit serious, contamination.
Thanks for answering, much appreciated.