One hundred and fifty nine prison officers have accepted voluntary redundancy under the prison reform scheme, Justice Minister David Ford told MLAs, on 18 September 2012.
Mr Ford said a total of 544 officers had applied for the scheme, and a further 139 would be released "when appropriate".
In reply to a question from Sinn Fein's Raymond McCartney, the minister said 60 new recruits were now in training in Millisle, County Down.
The SDLP's Colum Eastwood asked what progress had been made on the installation of full body scanners in prisons.
Mr Ford said the first millimetre wave scanner had been delivered to Magilligan Prison in preparation for the pilot there, and a second such machine was due for delivery to Hydebank Wood Prison.
An application had been made for permission to test transmission x-ray scanners, he added.
Anna Lo of Alliance was concerned about the possible effect of scanners on pregnant women.
The minister said the use of millimetre wave scanners was increasingly common in airports and they did not using ionising radiation.
Mr Ford said the use of transmission x-ray scanners raised the issue of pregnant women and young people.
He said there was no intention to use millimetre wave scanners on female prisoners.
Social Development Minister Nelson McCausland answered questions on a number of matters, including the replacement of double-glazed windows in Housing Executive homes, the role of the Ilex urban regeneration company in the Fort George redevelopment site in Londonderry and the Welfare Refom Bill.