Development of the port-based diagnostic and service system integration in the Tokamak has been a challenging task for ITER (Nuclear Facility INB-174) engineering. Port integration is demanding more work on ex-vessel to identify electromagnetic thermal and nuclear environment in interspace and port cell regions. Protecting the diagnostic equipment in the interspace & port cell regions poses considerable engineering constraints. This paper will focus on the normal and accidental environmental conditions such as seismic, magnetic field, radiation, pressure, temperature etc., with particular interest on US Domestic Agencies (USDA) based diagnostic systems.