Young offenders housed at Western Australia's high-security adult Hakea prison could be there even longer because of safety fears among officers tasked to guard them.
Nearly five months after a riot that wrecked WA's only juvenile prison, Banksia Hill, more than 100 teenage prisoners are still housed at Hakea.
The Department of Corrective Services is preparing to return the young offenders to the remodelled juvenile detention centre, which had to be repaired at a cost of $1.5 million after the January 20 riot.
But Toni Walkington, branch secretary of WA's Community and Public Sector Union, said youth custodial officers were refusing to go back to Banksia Hill until significant safety concerns were addressed.
"The overwhelming message from staff is that they were not going back until they are consulted on all their concerns," Ms Walkington said.
"Our members want to know that all remedial work on unit offices and cells is complete, safe and fully tested. They have to be convinced first."
Ms Walkington said the list of demands included an extra recreation area for young prisoners, additional staff training and testing of new security measures including metal detectors.
"The testers need to replicate the aggression the children showed at the time of the riot when they smashed windows, broke out of cells and climbed fences," Ms Walkington said.
A legal challenge by the family of a young inmate to the transfer of teens to Hakea failed in the WA Supreme Court but Chief Justice Wayne Martin acknowledged conditions at the prison - including 23-hour lockdowns, use of physical restraints, and continued chronic staff shortages - were "less than optimal".
The department has previously said it aimed to have the young offenders back at Banksia Hill by the end of this month.