B787 First Officer reported a 'right pack' EICAS message during climb out along with a 'fireworks' type of odor in the cockpit and passenger cabin. Crew ran checklist but did not comply with the 'reset' portion of the procedure for fear of losing the operating pack. Crew elected to return to departure airport versus continuing on with ETOPS flight on one pack.

Narrative

Diversion to ZZZ due to single Pack Failure. Departing from ZZZ en route to ZZZ1 we experienced a R Pack EICAS Messages on climb out. We had also smelled a certain firework; type smell that had been noticed by Flight Attendants and passengers. Originally we were not sure where the smell was coming from but all indications had looked normal until we lost the R Pack. We proceeded to do all non-normals which had called for a reset. We elected as a crew that a reset could possibly trip off the remaining good pack so we elected to forgo that specific item. After completing all checklist we were unsure if we wanted to continue our very long fight on a single pack so we used the satellite phone to have a discussion with the dispatcher; Maintenance Control; and the Chief Pilot. After a lengthy discussion we all had agreed that we did not want to risk a flight on one pack over the ocean into ETOPS airspace. At that point we decided to return to field and land back in ZZZ. We were overweight so we did have to jettison fuel and we ran all associated checklists. We coordinated with ATC; Flight Attendants; and spoke to the passengers. We then returned back to ZZZ with no further issues.