Buried Radioactive Materials Found; NRC Withdraws April California Emergency After Investigation

During the conversion of a former Maine World War II plant used for weapons support , radioactive contamination was discovered on sub-floors, according to a NRC statement.  The non-emergency alert issued July 24-26 concluded the materials found underground would not be life threatening.


"During conversion of the former Waltham Watch Co. property to offices and apartments the property owner discovered sub-floor areas to be contaminated with radium-226 and americium-241.

"The consultant submitted that the property had functioned as a watch factory; that during World War II the site was used to support the war effort; and that radium was used in self-luminous paints for watches, nuclear panels, aircraft switches, clocks, and instrument dials starting in the early 1900s and was still used as late as the 1960s. The americium was likely not part of the dial painting process and may have been associated with a former tenant.

"The consultant reported on radioactive waste manifest dated July 24, 2012 that a total of 890 microCuries (approximately 727 microCuries of americium-241 and approximately 163 microCuries of radium-226) was removed from the property. These materials are in addition to 10 microCuries of radium-226 that was removed from the property on May 23, 2012. In aggregate, the activities of materials meet the reporting requirements of 105 CMR 120.281(A)(1). Radioactive materials discovered and removed were mostly found under layers of flooring in areas of original wood subflooring materials in apartments not yet inhabited. The americium-241 was confined to two areas whereas the radium-226 was discovered in many areas. Final status surveys performed by the consultant indicate that no radioactivity is present above natural background levels in post-remediation areas.

"The Agency [Massachusetts Radiation Control Program] continues to investigate this incident and has performed on-site inspection of the specifically licensed person providing decontamination and decommissioning services to the property owner of the site."


Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf

This source is not amongst those sources or devices identified by the IAEA Code of Conduct for the Safety & Security of Radioactive Sources to be of concern from a radiological standpoint. Therefore is it being categorized as a less than Category 3 source.


Point Beach Nuclear Power Plant in Wisconsin issued an emergency alert April 26 for toxic gas in a vital area of the plant during maintenance. Upon investigation, the amount of gas was below the level necessary to have issued an alert. The prior alert is therefore retracted.