2010-08-16

In September 2008, the Nuclear Regulatory Commission (NRC) conducted a workshop on the security and continued use of cesium-137 chloride (CsCl) sources. CsCl sources are widely used in irradiators to sterilize human blood, in biomedical and industrial research, and for calibration of radiation instrumentation and dosimetry. Gamma-ray irradiation of lab animals by CsCl-containing devices is widely used in hematology, immunology, and stem cell biology research.

CsCl sources have come under scrutiny from a security standpoint because cesium is a compressed powder that is highly soluble in water and dispersible as an aerosol. Alternatives such as x-ray irradiators and cobalt-60 irradiators could be used in some cases, but not all; and the cost of switching to these alternatives would be financially prohibitive to most users.

During the September 2008 workshop, the NRC solicited comments from stakeholders on a draft paper that discussed alternative CsCl sources and technologies, a phase-out of CsCl, additional enhanced security measures, and other potential future requirements. ASH submitted comments urging the Commission to consider how the elimination of CsCl sources would compromise care and research that leads to development of clinical treatments for patients. Dr. Steven Sloan, Medical Director Pediatric Transfusion Medicine at Children’s Hospital Boston, and ASH staff participated in a focus group organized by the NRC on this topic in 2009. ASH also shared its concerns with the staff of Representative Edward Markey (D-MA) who has sponsored legislation that would give the NRC authority to further regulate radiation sources such as CsCl.

In November 2008, NRC staff submitted a memorandum outlining three possible options for the Commission’s consideration regarding the continued use and security of CsCl sources. The option recommended by NRC staff for approval, and for which ASH advocated, suggests maintaining current CsCl use in blood irradiation, biomedical research, and calibration, while also advocating for developing enhanced security systems for new and existing units and for developing a Commission policy statement. This option also acknowledges that significant impediments exist to any potential phase-out of CsCl and states that there is insufficient information available to develop a technical basis for rulemaking. The NRC is moving forward with adapting the staff recommendations and has released a draft policy based on the report. ASH is pleased that the NRC staff’s analysis and conclusions echoed the Society’s concerns. ASH will continue to monitor this issue and keep members updated on any future developments.

The NRC is seeking comments on the draft policy, and will also hold a public meeting November 16-17, 2010 in Rockville, MD. ASH will be submitting comments on this proposed policy and is looking for interested members to participate in the stakeholder meeting in November. The deadline for nominations for panel discussion members is October 6, 2010. If you are interested in participating or have any comments on the proposed policy, please contact ASH Scientific Affairs Manager Ulyana Desiderio at udesiderio@hematology.org.

back to top