Some items from today’s Nuclear Regulatory Commission’s Event Reports page:
1. The Yaffe Iron and Metal Company reported to the Oklahoma Department of Environmental Quality that the scrap metal yard had discovered an “orphaned radioactive source” in an outgoing shipment of scrap aluminum. The source was contained in a fifteen inch metal rod. The source of the radiation is thought to be Radium-226. Because the rod had been at the scrap yard for an undetermined time, the possibility of worker exposure exists. According to the Event Report: “The State of Oklahoma is currently on the scene investigating and will determine a list of potential individuals who may have been exposed to the source. A preliminary assessment has determined that one individual received about 600 mRem to the hand.”
2. Last Friday, two employees working for Nondestructive and Visual Inspections (NVI) received an exposure to excess radiation while using a radiography camera to inspect a pipeline in Wyslusing, Pennsylvania. One of the employees noticed that the indicator that shows full retraction of the camera’s radioactive source had not popped out. Both employee’s survey meters read zero at that time. However, one crew member’s survey meter was chirping, “but not very loudly.” Both crew member’s alarms had been inspected prior to beginning the job. The crew managed to manually crank the source back into the camera. After completion of the repair, both crew member’s badges were off-scale. The crew reported the exposure to NVI’s Radiation Safety Officer and were removed from work. The badges were sent for processing, and the whole body exposure of the two men were reported to be 5133 mR and 1447 mR. Cause of the malfunction is under investigation.
3. Last week, there was a similar event at a Valero refinery in Benicia, California. Two workers employed by TC Inspections were using a similar radiography device when the source retractor failed and had to be manually reset. One member of the crew was determined to have received 10 mR of exposure. The cause of the malfunction is thought to be excess wear on the aluminum camera fittings, preventing proper retraction of the iridium source, combined with failure to follow proper procedures.
4. In a followup report to an August incident, Jeppeson Radiation Oncology in Bay City, Michigan said that a survey of a number of cases at the Bay Regional Medical Center showed fifteen additional cases where medical radiation dosage was at least 25 per cent less than the prescribed dosage. Examination of Bay Regional’s radiation procedures is underway.
5. On October 5, 2011, a patient at Lankenau Hospital in Wynnewood, Pennsylvania, received radiation treatment. The patient had received a pregnancy test prior to the treatment. The results of the pregnancy test were negative. Last week, the patient reported to the hospital that she is now pregnant. Subsequent tests showed that the fetus was 10 days old at the time of the radiation treatment. Fetal dosage was estimated to be 17.4 rads.
6. Yesterday, a security officer at Colorado’s Fort St. Vrain Independent Spent Fuel Storage Installation noticed that the inlet screens at the fuel storage facility were 95 to 100 per cent blocked by ice. The inlet screens provide a cooling path for the used fuel. The problem was remedied by “lightly hitting the screen by hand.” (One wonders if this is a long term solution. Doesn’t it frequently get cold in Colorado in the winter? I’ve seen The Shining.) The storage facility holds spent fuel from the Fort St. Vrain nuclear power plant, which was decommissioned in 1992.
7. During a regularly scheduled fire inspection yesterday at the Wolf Creek nuclear power plant in Kansas, it was discovered that the facility did not meet requirements for control room evacuation during a fire. Inspectors say that a fire requiring control room evacuation could lead to steam generators overfilling and result in possible damage to the turbine driven auxiliary feedwater pump. The plant’s compensatory measure consists of an hourly fire watch. Changes in fire evacuation procedures are in the works.
8. A system vulnerability assessment at the Calvert Cliffs nuclear power plant in Maryland yesterday showed that the emergency diesel generator for the Unit 2 reactor did not meet fire safety standards. A review is underway about possible solutions. Meanwhile, the reactor continues to chug along at full output.
9. And finally, the Control Room Ventilation System at the Diablo Canyon nuclear power plant was found yesterday to be potentially inadequate in case of a design basis accident. Inspectors determined that control room air could be bypass the plant’s filters under some scenarios.