But experts cast doubt on their expertise, equipment and chances of success.
The plot was foiled when police raided homes and arrested five suspects in Bandung, West Java, last week, the sources with direct knowledge of the plot said. After the raids, police spoke of a plan to explode a “chemical” bomb but provided no other details……

The three counter-terrorism sources, speaking on condition of anonymity, said the militants had hoped to transform low-grade radioactive Thorium 232 (Th-232) into deadly Uranium 233 (U-233).
The highly radioactive uranium would be combined with the powerful home-made explosive triacetone triperoxide (TATP) to create a “nuclear bomb”, according to an instruction manual used by the militants and reviewed by Reuters.
In fact, the device would be, at best, a radiological dispersal device or dirty bomb that could spray radioactive material when the conventional bomb exploded.

A spokesman for Indonesia’s national police, Inspector General Setyo Wasisto, declined to confirm or deny the plot to construct the device, but said it would have been more potent than the two bombs made from TATP that killed three police in Indonesia’s capital Jakarta in May.
“If this bomb was finished, it would have had a more destructive impact than the bomb made from ‘Mother of Satan’,” he said, using the nickname for TATP.
“It could burn anything and make it hard for people to breathe.”
Thorium-232 can be transformed into Uranium-233 but requires the Thorium to absorb a neutron, a process that needs powerful irradiation, generally from a nuclear reactor, according to three analysts contacted by Reuters and the website of the World Nuclear Association, which represents reactor vendors and nuclear engineers, among other industry stakeholders….

One senior Indonesian counter-terrorism source said the Bandung-based cell had bought a large amount of a household item and had begun to extract the Thorium. Reuters has chosen not to name the item.
“They needed three weeks. It was still only one week (into the process when police raided),” the source said…..

According to police, the suspected Bandung plotters were members of JAD and were considering targets like the presidential palace in Jakarta and police headquarters in Bandung and the capital….. (Reporting by Tom Allard and Agustinus Beo Da Costa Additional reporting by Stefanno Reinard; Editing by Ed Davies and Nick Macfie) https://au.news.yahoo.com/a/36844136/exclusive-indonesian-militants-planned-dirty-bomb-attack-sources/