When this occurs there is a rapid rise in temperature and pressure within the reactor causing {HEAD ~ emergency vent valves} to open in {TAIL ~ order} to reduce the pressure within the reactor and vent the reactor contents 
to open in
When this occurs there is a rapid rise in temperature and pressure within the reactor causing { HEAD ~ emergency vent valves } to open in { TAIL ~ order } to reduce the pressure within the reactor and vent the reactor contents
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH