If memory serves me correctly, the nacelle anti-ice system is provided by a switchable anti-ice valve that allows warm bleed air into the cowl of the engine nacelle. The air is circulated around the cowl and escapes through the anti-ice pressure-regulating valve to atomsphere when it achieves a set pressure. The NAI anti-ice valves are controlled from the cockpit by pushbutton switches. When selected on, the switchlights illuminate blue when a set bleed air pressure is sensed in the cowl or illuminate amber to notify the pilot of abnormal operation.
If the anti-ice pressure-regulating valve malfunctions in the closed position, one would hope that some sort or overpressure regulating safety valve would release the bleed air from the cowl so that structural failure of the cowl would be prevented.
In the case presented in this thread, we are faced by a structural failure of the engine cowl immediately after the application of maximum thrust for the go-around. The engine does not appear to exhibit any evidence of blade or component shedding that might have precipated the failure of the cowl.
Where do we go from here?