The Atomic Energy Regulatory Board's (AREB) withdrawal of authorising Delhi University (DU) to use radioactive sources in its laboratories has started affecting the research work of post-graduate students and teachers. After repeated written requests from teachers and students, the university has requested the AREB to lift the ban on at least on mild sources of radiation. The ban was imposed last month, after the university had failed to submit its final reply on the radiation exposure incident at Mayapuri scrap yard in Delhi within the time-frame. The ban bars use of even mild radioactive sources which are harmless. Physics and chemistry department teachers argue that as much as 80 per cent of radioactive sources required in practical modules are mild and harmless and can be used following the basic precautions. "The entire course will be affected. In 60 per cent cases, radioactive substances required for reactions are harmless. If we resort to an alternative method to conduct experiments outside the university, the quality will suffer," said one of the professors teaching nuclear physics module in M.Tech. Looking at the damage that the ban will bring for research students, the university departments have already started getting their act together. Apart from security measures being put in place, a three-member panel has also been formed to look into the report prepared by the committee into the radiation fiasco. Recently, Dr A.K. Bakshi, head of the department of chemistry, and the university registrar met AERB officials and handed over the much delayed report on the Cobalt-60 incident prepared by a three-member committee. "The AERB has asked us to transfer radioactive substances that are not in use, besides, handing over to them a list, classifying the materials in the department's possession," Prof Bakshi said. He said while the department was hopeful that the ban on weak sources would be lifted, the use of X-rays and other strong sources would be stopped till the AERB is satisfied with the measures put in place by the university. Confirming the university's move, vice-chancellor Deepak Pental said, "We have written to the AREB and are hopeful that our request will be looked into. The AREB is sensitive to the university's needs for holding practical tests and research in M.Sc courses." Pental said, "As of now, we need not jump to any conclusion. The strong sources would have to be put away for some more time, but yes looking at the need of the hour, the association might agree on allowing mild sources, temporarily."