The Australian Nuclear Science and Technology Organisation's (ANSTO) is fixing tech errors in response to workers’ concerns.

The Community and Public Sector Union (CPSU) says its members have reported a range of concerns about data in ANSTO’s SAP system, which runs a range of its internal operations including employee leave, rosters and pay.

CPSU deputy secretary Beth Vincent-Pietsch said concerns “ranged from privacy issues to problems with leave allocations and superannuation payments”.

A recent glitch saw around 250 staff afforded more leave than they were entitled to.

“Staff who have been identified as having excess leave have been notified that this excess balance will be deducted in the next pay cycle,” the union said in a statement.

“The reason for this error is not clear, as many of the affected staff believe that they checked their carryover when the new SAP system was implemented last July and found no error at the time.”

The union says the situation must be handled delicately to avoid disadvantaging anyone that had made plans or already taken too much leave based on the incorrect figures, but claimed ANSTO is making “an immediate deduction”.

An ANSTO spokesperson told reporters that only “a small number” of staff went over their actual entitlement.

“An independent payroll consultant was immediately engaged to undertake a review, and already more than 80 percent of the affected staff have had their correct balances restored," the spokesperson said.

“We are working individually with all staff who have concerns or questions.”