The proposed new prison on Spike Island, Co Cork, will hold 450 inmates and will be open in three years, Minister for Justice Michael McDowell has said.
The new facility will include separate male and female sections as well as one for juvenile offenders.
Mr McDowell told delegates at the Prison Officers' Association (POA) annual conference that the new prison would replace the closed facility on the island. It would also replace Cork Prison which is experiencing overcrowding.
Cork Prison needs to be replaced with a modern facility with the full range of work, training, educational and medical services for inmates as well as predominantly single cell accommodation with proper sanitation facilities, Mr McDowell said.
As part of the Spike Island redevelopment plans, a new bridge will be built to the island, which currently can only be accessed by boat. Mr McDowell told the prison officers that the new island jail was just one element of a wider plan to modernise the entire prison system.
The new Mountjoy Prison at Thornton Hall, north Co Dublin, will open in three years and will hold 1,100 inmates. Preparations are well advanced and construction would begin around April next year.
An additional 150-bed wing is due to open at Wheatfield prison, Dublin. And 100 extra spaces would be provided at the open facilities of Loughan House, Co Cavan, and Shelton Abbey, Co Wicklow.
He was responding to criticism from the POA that overcrowding was becoming so acute in jails that a revolving door system was beginning to emerge again.
"Less than 3 per cent of prisoners are on temporary release at any one time. We did have a situation under the rainbow government when the revolving door meant up 20 per cent of prisoners were out on temporary release, that's no longer the case," he said.