Wednesday, February 20, 2019

The problem with the uranium at the Grand Canyon story

There's a hot story right now about three buckets of uranium ore that was stored at a museum at the Grand Canyon, with a claim of it being quite radioactive and a particular employee claiming the whole thing was covered up. The problem is the employee's numbers are off by a factor of 1,000. The presentation slide has the outside background rate at 2 mRem/hr. That's gotta be wrong; an average exposure in the Colorado Plateau is about 90 mRem per year, which would be something like 0.01mRem/hr aka 10 uR/hr. The buckets at the surface were really more like 300uRem/hr, or 3mRem/hr.

Saturday, February 09, 2019

Image received from the International Space Station

I received an image that was being transmitted from the International Space Station as it passed nearly overhead this evening. They broadcast at about 25W of power at 145.800 MHz; an amount that is easily heard and received since the communication is line-of-sight and only a few hundred miles away. They only use it on occasion so it was nice to hear they were planning on a few days of sending images. I used a generic SDR receiver and a simple dipole and piped the audio output to MMSSTV. Some of the noise in the center of the image was because I forgot to correct the receiver for the Doppler shift of the ISS as it passed by.