As a radiation safety officer, or a safety manager in a radioactive work environment, it’s your job to plan, plan, plan. That includes having a plan to stop – and clean up – radioactive spills. In lab, academic and testing environments, spills are the most common type radioactive “accident.”
They can range from large spills on counter tops or floors, to something as small as a leaky pipette or unwitting spray that emerges when you open a new stock vial. Some are significant, some are practically undetectable – but all require an efficient, practiced and knowledgeable response.
SWIMS your way through a radioactive spill
SWIM is a simple acronym to remember and a good place to start if you’re in the process of establishing a radiation exposure response plan, or you simply want to review and amend the current one. SWIMS has been adopted by entities around the nation – from the Navy, to universities and defense labs.
- S – Stop the spill. If it’s a larger spill, you may need to stop all activity while you think and assess the situation.
- W – Warn others. This might be as simple as a verbal warning or it may also include a call to emergency response personnel
- I – Isolate the spill area. The spill area must be isolated and restricted from access or contact from anyone not involved in the response/cleanup efforts.
- M – Minimize radiation exposure. Monitor the situation carefully. Look for additional signs of contamination around the spill area and on yourself or others.
- S – Stop ventilation if it will help. Stay on the scene until emergency personnel arrive if the spill is significant.
This acronym doesn’t have to be addressed in order – it should simply serves as a mantra that keeps you and others focused on the tasks that need to be done.
Stop the spill
The first step in stopping the spill is to prevent it from getting worse. If you aren’t already, it’s imperative that you wear gloves and other relevant protective clothing or shielding that protects you from skin contamination. Don’t worry about cleanup until you‘re sure the spill is completely resolved and contained. Pick up or right any spilled containers, and use absorbent material to wick up what’s spilled to prevent it from spreading.
Others need to be warned. Of course, ‘W’ can come before or alongside ‘S’ in most situations. Alert those around you of what’s happened – especially anyone within about three feet of where the spill occurs. Depending on the nature of the spill and the environment, you may need to delegate this task to continue cessation and containment.
The Radiation Safety Officer (RSO) should be notified immediately –even for minimal spills.
Isolate the area and the spill
The last thing you want during a spill is for someone to walk through and add contamination to the list of incidents. Use physical barriers to block the area. Caution tape or rope with cones are effective, but even a table across a walkway or door will work. Barriers should be obvious obstructions so others must move them or circumvent them to get through.
You will need to leave enough room to work in – ideally this would be a spill boundary that’s at least three-feet away from the outermost drop of radioactive material. Nobody should be allowed to penetrate the spill boundary unless they’re wearing proper protective equipment. If someone does cross the spill boundary, gear or not, they should not be permitted to leave until thoroughly surveyed by the RSO.
Spills should be contained and cleaned up – working from the outside borders to the inside, or from the top of the spill to the bottom (for example, if the spill moves from the counter or a table to the floor). As you clean, any towels, rags or other cleanup materials should be isolated in a plastic bag immediately after they’re used. Anyone holding or touching the bag should be wearing protective gloves.
Minimize radiation exposure
The best way to minimize radiation exposure is to stop and think. Rushing in doesn’t help anyone and can often make the situation worse as a hurried response can lead to further contamination or a violation of your company’s well-planned safety procedures. Instead, take a moment to stop and think about what is needed to address the situation at hand:
Are respirators necessary? What clean up equipment is necessary? Do you have what you need on hand or does something need to be procured? Have the right entities been contacted? Are the spill boundaries set up effectively? By assessing the situation calmly and logically, you’ll minimize exposure to yourself and others.
If shutting down applicable ventilation systems requires getting in the way of the spill, take extra precaution – wearing the right gear and respecting before/after survey and check out protocols. Otherwise, ventilation and recirculating air systems should almost always be shut down to avoid contamination by air. Keep in mind that ventilation may include things like refrigerators, fans, open windows, venting computers, etc.
Survey the radioactive spill area when you’re done
Once the area is cleaned up, it must be surveyed. Survey the entire area, including the areas immediately adjacent to the spill boundaries to ensure radiation levels are within acceptable limits. Those who worked on the contamination cleanup should also be surveyed. If there is any doubt about what those acceptable limits are, consult the Nuclear Regulatory Commission’s Reg Guide 18.6, which serves as the industry standard.