The report, produced by the Independent Monitoring Board, says the prison is operating in a safe manner but the reduced level of prison officers is putting them under unsustainable pressure.
It says the low numbers affect staff wellbeing which has a potential knock on effect on prisoners.
The report says the prison has never reached the 102 officers recommended. The board believes the is unsustainable and leaves the “safe running of the prison exposed”.
The report adds: “The board is aware this is a national issue and would ask the Minister what further proposals are planned as the recruitment campaigns to date have not supplied the 1,500 officers required.”
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The prison also has a “concerning” number of uncompleted Offender Assessment System reports.
Concern over staff shortages extended to management level, the report said, noting that a pledge to provide a full management team by March 2015 was not achieved.
There was considerable praise for the staff working in the Care & Support Unit for their managing of difficult prisoners.
The inspection was carried out from March 2014 and February 2015.