Joe O'Reilly was on suicide watch and was checked by prison staff every 15 minutes on Friday night after losing the appeal against his conviction for murdering his wife Rachel.
However, despite the precautions, prison sources say the 36 year-old was "not as downbeat as expected", even though his life sentence is now official. O'Reilly is being offered counselling this weekend.
He was led back to his cell at the Midlands Prison in Portlaoise on Friday after the Court of Criminal Appeal rejected his appeal.
O'Reilly was convicted in July 2007 of murdering his wife at their home in Naul, Co Dublin, in October 2004. His lawyers have not ruled out an appeal to the Supreme Court.
"There was no round of applause by prisoners when he was brought back. He's quiet; he's always kept to himself. We expected him to be more downbeat but he seems fine. He's never been one to show too much emotion," said a prison source.
O'Reilly will remain on suicide watch until prison authorities believe he is no longer a risk. He returned to his job of cleaning the prison landing this weekend.
Meanwhile, the two ringleaders of a mini-riot at Dublin's Mountjoy prison on Thursday have been transferred to prisons outside the capital and lost some of their privileges.
The row erupted when two inmates, Jeffrey Finnegan and Graham Byrne, attempted to grab a set of keys from an officer who had been dragged into a cell on a landing in the B-wing.
Finnegan, 29, from Rathvilly Drive, Finglas, is serving a four-year sentence for unlawful use of a stolen car and other driving offences. He was questioned about the murder of Coolock woman Donna Cleary, who was killed at a birthday party in March 2006, but was freed because his detention was illegal.
Byrne, 34, from Sean McDermott Street, Dublin, is serving eight years for conspiring to steal €200,000 from a Securicor van in 2007.