Jack Beales, 93, of Rhyl, carried out the attacks while she was a young girl, mainly when he was in his 70s.
He denied five charges of rape and six other sexual offences but was unanimously convicted by the jury at Mold Crown Court on 9 December.
Sentencing him on Wednesday, Judge Rhys Rowlands said Beales had destroyed his victim's childhood.
His victim, now aged in her 30s, took to the witness stand to read her victim impact statement.
The court heard the abuse began when she was aged six and continued for about 10 years.
She said she had wanted to commit suicide and hoped, when she confronted Beales last summer, it would bring some kind of closure.
But she said it had not and she was still on strong medication for depression and anxiety, and was awaiting counselling.
The court had heard she confronted Beales at his home and he admitted in front of her mother and his wife he had groped her as a child.
He later said "that was what men did".
The woman said every time she came into contact with Beales he made hurtful comments.
She said: "Once again I felt suicidal and felt I could not continue suffering while he was living a happy and carefree life, with no apparent suffering."
The woman said one of her biggest wishes in life was to start a family.
But she added: "I worry that there may be internal physical damage due to the abuse which may mean I am unable to conceive or carry a child to full term."
She said she felt she could not trust anyone and saw the world "as a very dangerous place".
"I am hyper vigilant when kids are left unattended or unsupervised around men," she told the court.
"I feel unable to relax, and as though I have a responsibility to be watchful over others."
Defending barrister Andrew Green said Beales had no previous convictions and accepted some acts had taken place but he denied other allegations including all the rapes.
Jailing him, Judge Rowlands said Beales did not have "an ounce of remorse" and was "devoid of any moral compass at all".
He will have to serve a further 12 months on licence.
Det Insp William Jones, of North Wales Police, said: "John (Jack) Beales was a manipulative and depraved sexual predator who committed multiple offences over a sustained period of time. He is now thankfully behind bars.
"No child should ever have to experience what the victim went through."
An NSPCC Wales spokesman said the victim "must be commended for showing incredible bravery in reporting what happened to her so Beales could eventually face justice for his crimes".
The victim of a pensioner jailed for 13 years for horrific sex attacks has told of the abuse that ruined her life.