Whew, busy and tiring shift today. Been messing all day with 5 incoming Cf-252 sources.  The two hottest ones are now no problem; they’re within massive shielding.  The other three, though, are the portable 0.5 µgram ” bucket o’ ” size. 

And they’re not really a problem, per se.  In a few years there’ll be complaints about how wimpy they are.  But for now, fresh at the start of their very first 2.5 year half-life, each flirts with being a Radiation Area:  30cm dose rate of 5 mrem/h  (50 uSv/h). 

So what happens if you get them close together–say, inside a neutron source cabinet?  Why, if you’re not careful, you make a Radiation Area by overlapping their radiation fields.  Had to shuffle buckets like cards and separate them like unruly children.