Again which micro controller for electromagnetic noisy environments

Dear Friends,

I am about to chose a micro controller for another power control unit
application. Earlier I used Renesas (26 series) it was immune enough. For
my new application I need some new features like self programming
controller which can update its firmware with a new version from a serial
port ,better tools support, at least 3 serial ports, no limitation in
using all serial ports ( in Renesas 26 series ,while using debugger one
serial port does not work). For this new application I am considering AVR
, but I am doubtful about its immunity to noisy enviroment like power
switching ( 230V AC , 60A contactor switching taking place within a radius
of 1 feet )

Does any have experience in using AVR in noisy environment say power
switching or automotive applications.

I am aware that bette layout and engineering guidelines should be
followed.
But inspite of that I may get problems if the controller is sensitive.

Any suggestions 

Thanks in advance

Narender Rao