The following information was received from the State of
New Mexico via email:
A radioactive gauge was found in a Farmington, NM scrap metal facility and reported to the New Mexico Radiation Control Bureau (Bureau) on Friday, April 18, 2008. An employee at the scrap metal facility reported that a semi-truck delivering scrap metal to a Colorado metal recycler was found to have a 'hot spot'. The radioactive bale was isolated and returned to NM.
Using information from the label on the gauge, the generally licensed source was traced to a NM radioactive material licensee. The Bureau's investigation included a review of Colorado's fax of DOT-SP 10656 Shipment Approval Form (Colorado survey: 1.8 mr/hr on side of trailer), interviews with personnel at the scrap metal facility, radiation surveys of the device, and interviews with licensee personnel. The Bureau's radiation survey of the gauge indicated exposure rates of 7-10 mr/hr at contact with the source housing and 0.3-0.5 mr/hr at one meter from the source.
Discussions with licensee personnel revealed the gauge was listed on the August 20, 2007 physical inventory and the Radiation Safety Officer (RSO) had been laid off on November 7, 2007 in the midst of a scheduled outage of operations that included removal of gauges from service. It appears the gauge was removed from service and discarded with other scrap metal, arriving at the scrap metal facility sometime in late March 2008.
The gauge was retrieved by the licensee and placed in secure storage. The loss of control of the radioactive source is attributed to lack of oversight of the licensee's radiation program during gauge removal operations. Based on scrap metal facility configuration, location of the radioactive bale on the semi trailer during transport, storage of the gauge upon return, and exposure rates from the gauge, it is estimated that public dose limits were not exceeded. The NM Environment Department is evaluating enforcement actions in response to the incident.
The
gauge was manufactured by Kay-Ray. It has a 50 mCi
Cs-137 sealed source, S/N
92B-03016 and was licensed to Public Service of
New Mexico.