The Nuclear Regulatory Commission (NRC) has directed agency staff to continue enhancing the security of cesium chloride radiation sources, while encouraging research and further technological developments for alternative chemical forms of cesium-137.

Concern over the security of these sources has led some people to advocate banning cesium chloride altogether; however, the commission said it believes that near-term replacement of cesium chloride sources in existing blood, research, and calibration irradiators is not practicable and would be harmful to the delivery of medical care, research and emergency response capabilities.

"Banning or phasing-out cesium chloride radiation sources at this time--before a replacement form or other technology is available--would be counterproductive, because society would lose the many benefits these sources provide in medicine, industry and research," said NRC's Chairman Dale E. Klein.

Security controls already implemented over the past several years have significantly improved the security of these sources, the NRC stated. However, it directed the staff to continue exploring new ways to further improve security, including working with federal and state agencies to define criteria for a "dispersible source of concern" that could then be used to guide research efforts to develop an alternative form of cesium.

The staff was also directed to develop a policy statement detailing the NRC's emphasis on security of cesium chloride sources, which fall into the International Atomic Energy Agency's Categories 1 and 2, and are widely used in irradiators to sterilize human blood, in bio-medical and industrial research, and for calibration of radiation instrumentation and dosimetry.