The young artists behind the Children Hospital's new collection

Benjamin Zinsli is hoping his colourful drawing of Noah's Ark will brighten up the day for other young patients at the Children's Hospital at Westmead.

The six-year-old, who was diagnosed with spina bifida and hydrocephalus soon after he was born, has taken comfort from the artwork on the hospital's walls during countless visits, and his own piece will now hang alongside them.

"When his teacher mentioned the Operation Art competition, he said he thought he'd give it a go to try to make other kids happy who also had regular visits," his mother Sally Zinsli said.

As part of his treatment, Benjamin has undergone scans enabled by nuclear medicine that will be produced in massive quantities in Australia by the end of next year.

The Australian Nuclear Science and Technology Organisation is building a new facility in Lucas Heights that will ramp up production of nuclear medical agents from 550,000 doses to 10 million doses per year, the equivalent to about a quarter of global supply.

Australia's emergence as a major exporter of the medicine will come at a time when the facilities that produce as much as 70 per cent of the world's nuclear medicine are due to shut down because of age.

Demand for nuclear imaging agent Technetium 99-mm is currently at about 40 million doses a year, but the general manager of ANSTO Nuclear Medicine Jayne Senior said this will rise in coming years.

"This is increasing as the world population expands and more countries modernise their health system," Ms Senior said. "So there will be a major deficit of supply, and that's where Australia comes in."

ANSTO's use of low-enriched uranium technology could also drive down demand for medicine based on high-enriched uranium and contribute to non-proliferation and nuclear security goals, she said.

The nuclear medicine department at Westmead Children's Hospital is the largest in Australia and in the top 10 internationally, and administers treatments to about 4000 children every year.

The head of the department, Professor Robert Howman-Giles, said ANSTO's facility would be important in advancing the field, including the growing use of PET scans for children with cancer.

"It's a major growth area worldwide," Professor Howman-Giles said. "The new facility is going to be looking at a lot more new agents."

Nuclear medicine treatments are mostly administered intravenously, and he said a welcoming environment is especially important in the hospital's preparation and injection rooms.

"We've got a lot of art in those rooms, the entire rooms have been painted with stories and cartoons, so you can be talking to them about that.

"We have some professional, very expensive art at the department, but the kids identify a lot more with what other children produce."

Benjamin's artwork will be on display along with 800 pieces by schoolchildren across NSW from this weekend at the Armory Gallery at Sydney Olympic Park. A selected 50 will be given to the Children's Hospital at Westmead.