Changes must be made to address the failures that led to tens of thousands of children being sexually abused in Australian institutions, the head of a royal commission says.

Branding the findings of the royal commission “a national tragedy”, chair Justice Peter McClellan warned that the sexual abuse of children is not just a problem of the past, with children continuing to be abused in institutions today.

Justice McClellan said many institutions failed children over many decades, while the child protection, criminal and civil justice systems let them down.

The royal commission has already called for significant reforms in areas such as the criminal and civil systems, as well as measures to make institutions safe for children.

Its final report, to be handed to the Governor-General on Friday, will outline further changes.

“There may be leaders and members of some institutions who resent the intrusion of the royal commission into their affairs,” Justice McClellan told the final sitting of the five-year inquiry in Sydney on Thursday.

“However, if the problems we have identified are to be adequately addressed, changes must be made.

“There must be changes in the culture, structure and governance practices of many institutions.”

Justice McClellan paid tribute to the child abuse survivors who shared their stories with the inquiry, saying they have helped the commission decide what should be done to make Australian institutions safer in the future.

Their personal stories had a profound impact on the commissioners and commission staff, he said.

More than 4000 individual institutions have been reported to the royal commission as places where abuse occurred, with tens of thousands of victims.

Justice McClellan said the number of children who are sexually abused in family settings or other circumstances far exceeds those abused in institutions.

“The sexual abuse of any child is intolerable in a civilised society.

“It is the responsibility of our entire community to acknowledge that children are being abused.

“We must each resolve that we should do what we can to protect them.

“The tragic impact of abuse for individuals, and, through them, our entire society, demands nothing less.”

Prime Minister Malcolm Turnbull and Opposition Leader Bill Shorten attended the final sitting with both acknowledging the courage of survivors.

Meanwhile, the survivors abuse are demanding the government immediately adopt the upcoming recommendations of a five-year inquiry into their suffering.

Joan Isaacs, one of the first people to give evidence against the Catholic church, praised its work.

“Not only did we have a voice but we have been heard and believed. Many, for the first time in their lives,” she told reporters.

“The job of the commission is done, but the journey is not over.”

While survivors were owed justice from the institutions and others, law changes were also needed to keep children safe.

“These recommendations must be implemented in their entirety and done so as soon as possible,” she said.

“To be able to change the future, we have to know the truth of the past.

“We have to accept it, we have to take responsibility for it, we have to move forward.”

Ray Leary, a child victim of the infamous Dolly Dunn paedophile ring, said the time for tears was over.

“I would like to let everyone know it is your time now, the royal commission is done, if you want to speak, come forward everyone is listening now,” he told reporters.

“No more tears for us, we are survivors and we are going to get it out there and we are going to be dealt with.”

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