Rome (CNN) Sister Veronica Openibo, a Nigerian-born nun, is one of only three women to address an unprecedented Vatican summit on clergy sexual abuse.

She did not waste the opportunity.

In clear, direct and unsparing language, Openibo challenged the church's culture of silence on sexual issues and said priests are too often put on pedestals. Openibo also criticized the practice of letting elderly clergy who had abused children retire quietly with their pension and good names in place.

"Let us not hide such events anymore because of the fear of making mistakes," Openibo said after reading a searing summary of abuse cases she has heard about during her work on sexual education in Nigeria.

"Too often we want to keep silent until the storm has passed! This storm will not pass by. Our credibility is at stake."

Sister Veronica Openibo stands next to Chicago Archbishop Cardinal Blase J. Cupich, left, and Father Tomaz Mavric as they wait for the Pope's arrival at the beginning of the third day of a Vatican's conference on clergy sex abuse.

At one point, Openibo appeared to look toward Pope Francis, who was sitting on the dais to her right, when calling for a policy of "zero tolerance" toward clergy who abuse children.

In calling for "zero tolerance," a policy whose definition appears to vary widely among Catholics, Openibo echoed the calls of dozens of abuse survivors gathered for protests and vigils on the streets of Vatican City this week.

Wearing glasses and speaking gently though plainly, she addressed the Pope directly as "Brother Francis." Openibo said she admired his candor and willingness to admit mistakes he made in evaluating the claims of Chilean abuse survivors about a notorious priest who was defrocked last year, and the bishops who covered up his crimes.

"Thank you for providing this opportunity for us to check and see where we have acted strangely, ignorantly, secretly and complacently," she said.

Openibo also thanked the Pope for allowing her to address the assembly of 190 Catholic leaders, 114 of whom are bishops and cardinals from around the world. About a dozen of the participants are women, most Superiors General of religious orders.

"Usually, it is just the men who come," Openibo said with a smile.

Who is Veronica Openibo?

Openibo was invited to address the Meeting on the Protection of Minors here in Vatican City through her role on the executive committee of the International Union of Superiors General.

In 2010, Openibo, who has a doctorate in pastoral education from Boston College in the United States, was elected as the first African leader of her religious order, the Society of the Holy Child Jesus. Founded in England by an American-born nun, the order focuses particularly on education.

The nun said her experience in the "Global North" -- fifteen years in Rome and three in the US -- give her a distinct perspective on the church's massive and morally compromising sexual abuse scandal.

Openibo said she has heard from African and Asian leaders who deny that clergy sexual abuse is an issue in their cultures, and watched young men in Rome attain an unearned, exalted status as soon as they enter the seminary.

"It worries me when I see in Rome, and elsewhere, the youngest seminarians being treated as though they are more special than everyone else, thus encouraging them to assume, from the beginning of their training, exalted ideas about their status," Openibo said. She also said the study of human development raises troubling questions about minor seminaries, schools in which teenage boys begin their training for the priesthood.

But Openibo saved her most challenging criticisms for the bishops themselves, many of whom she said have wounded the church's moral standing by covering up the abuses in their church.

"We proclaim the Ten Commandments and 'parade ourselves' as being the custodians of moral standards and values and good behavior in society. Hypocrites at times? Yes! Why did we keep silent for so long?"

Openibo said her eyes welled up as she prepared her speech, an experience, she recalled, that reminded her of watching the movie "Spotlight," about the Boston Globe's 2002 expose on the clergy sexual abuse crisis.

"How could the clerical Church have kept silent, covering these atrocities? The silence, the carrying of the secrets in the hearts of the perpetrators, the length of the abuses and the constant transfers of perpetrators are unimaginable," she said.

Members of Ending Clergy Abuse, a global organization of prominent survivors and activists, continued demonstrations in Rome on Saturday.

Openibo added, "At the present time, we are in a state of crisis and shame. We have seriously clouded the grace of the Christ-mission. Is it possible for us to move from fear of scandal to truth?"

After Openibo's address, Cardinal Blase Cupich of Chicago, one of the summit's organizers, told CNN that women's voices should be heard more.

"She spoke from the heart," Cupich said. "And the voice of a woman in the aula (hall) was very compelling, and is something that is causing bishops to say we need the voices of women more often in events like this gathering."

Evidence destroyed or not created

Also on Saturday, it was revealed that documents that could have contained proof of abuse in the Catholic Church were destroyed or never drawn up.

Archbishop of Munich Cardinal Reinhard Marx made the admission during a speech at the Vatican in which he said, "Files that could have documented the terrible deeds and named those responsible were destroyed or not even created."

He added, "The stipulated procedures and processes for the prosecution offenses were deliberately not complied with, but instead canceled and overridden."

The admission came on the third day of a historic Vatican summit focused on combating clergy sexual abuse. The day's theme was transparency, which Marx said could help to tackle abuse of power.

"Such standard practices will make it clear that it is not transparency which damages the Church, but rather the acts of abuse committed, the lack of transparency, or the ensuing coverup," he said.

At a press conference, Marx said that the information about destroying files came from a study commissioned by German bishops in 2014. The study was "scientific" and did not name the particular church leaders or dioceses in Germany that destroyed the files.

"The study indicates that some documents were manipulated or did not contain what they should have contained," Marx said. "The fact in itself cannot be denied."

Marx said he doubts the destruction of files related to clergy sexual abuse was limited to one diocese.

"I assume Germany is not an isolated case."