The AERB has given a two weeks time to respond to the show cause notice.
1 person was killed and 7 others were injured after they were exposed to radiation in a scrap market in Mayapuri in the first week of Apr 2010.
"We have given two weeks time to the university to provide its explanation," Chairman, AERB S S Bajaj said in Mumbai.
The move by the AERB came after the Delhi police traced the origin of the radioactive Cobalt-60 found in Delhi's Mayapuri scrap market to a chemistry lab on Thursday, Apr 29.
"We have issued a show cause notice to explain about the unauthorised disposal of radioactive cobalt 60 source from one of its labs as scrap thus violating the safe disposal of radioactive waste rules and radiation protection rules," Bajaj said.
"We are also suspending permission to use all the radioactive sources which the university holds," he said.
"Once we get a reply from the University in two weeks, we will take the next step of punishment under the Atomic Energy Act," he said.
Bajaj said that AERB discovered that the authorisation for the gamma cell was given by the then Directorate of Radiation Protection in January 1970 of the Department of Atomic Energy.
"Negligence was there. Radioactive materials should be disposed off in controlled condition. Strict guidelines have been formulated by Atomic Energy Regulatory Board. It appears DU has not followed it," a senior Delhi police official said.
Delhi University Vice Chancellor Deepak Pental on Thursday, Apr 29, accepted 'moral responsibility' for the mishap after the radioactive source to the scrap was traced to university's chemical lab.
"The university is very apologetic and takes moral responsibility (for the accident)... No amount can compensate for the damage," Pental had said.