Castle Hill High School: Radioactive ‘yellowcake’ is discovered at Sydney campus

One Australia’s largest public schools has been partially locked down after a radioactive material that can cause kidney damage was discovered in a storeroom.

A box labelled ‘yellowcake’, which is concentrated uranium oxide powder, was found sitting on a science storage shelf at Castle Hill High School in north-west Sydney.

The box is understood to have been in the room for decades and was only discovered after white powder, suspected to be asbestos, fell onto it. 

The school was the centre of an asbestos scare in 2020 with several classrooms closed for a month after the dangerous material was detected in the roof.

A teacher said Castle Hill School’s principal confirmed the science storeroom was off limits. The school was the centre of an asbestos scandal in 2020

Teachers were told the science chemical storeroom was strictly off limits until further notice in an email from Castle Hill School principal Georgina Fleming (pictured)

A teacher at the school told news.com.au that the ‘incompetence is staggering’.

‘Somehow it got put in a red box and left in the storeroom… forever,’ he said.

Teachers were told the science chemical storeroom was strictly off limits until further notice in an email from Castle Hill School principal Georgina Fleming.

Ms Fleming said in the email that the school was ‘testing suspected asbestos and other material’. 

The room remains ‘isolated and secured’ until the material is properly tested and is likely to be removed by a hazmat team this week. 

Parents and guardians were also advised by email. 

Students were given yellowcake powder to set off radiation counters in classroom science experiments in the 1960s.

Yellowcake is radioactive, though not highly. It is extremely long-lasting, with a ‘half-life’ of over 4 billion years, meaning that it emits radiation at a slow rate.

The main reason it is considered toxic is it can cause kidney damage if inhaled.

The material is derived from the milling and chemical processing of uranium ores.

The Department of Education confirmed in a statement that ‘a potentially hazardous material’ was found in a ‘locked science block storeroom’ at the school on August 30.

‘The storeroom was not accessible to students and the material was in a sealed box and believed to have been used to support science experiments in the past,’ the statement said.

The statement said the science block was cleared after inspection as ‘safe for normal use’.

The toxic concentrated uranium powder is believed to have been sitting on the science storeroom shelf for up to 50 years. Pictured: stock image of a storeroom

Castle Hill School told parents in an email about the yellowcake scare but the science block is understood to be safe to use as normal

Staff and students complained for several years before 2020 that strange dust was falling from the ceilings before the asbestos was identified.

The school’s then principal Vicky Brewer, who retired in 2021, is understood to have ignored the complaints. 

The NSW Department of Education received a positive asbestos test result from the school four years earlier in 2016, but told the school it had come back negative.

Daily Mail Australia approached The Department of Education and Castle Hill School for comment.