NukeWorker Forum

Reference, Questions and Help => Nuke Q&A => Lessons Learned => Topic started by: RadConSuper on Jul 09, 2004, 12:30

Title: Moly-99
Post by: RadConSuper on Jul 09, 2004, 12:30

Could someone tell me what the dose rate from a 1130 Curie Moly-99 source would be. Also what the tenth value layer for DU is? Thanks for the help!

Title: Re: Moly-99
Post by: Roll Tide on Jul 09, 2004, 12:59

Quote from: RadConSuper on Jul 09, 2004, 12:30

Also what the tenth value layer for DU is? Thanks for the help!

http://www.labor-spiez.ch/e/bg_info/du/du_study_print.pdf
page 7 says 5 times better than lead. (Trying to get time to work on the calculation. I am assuming you need the Tc-99 daughter as well (with 66 hour half-life of your parent nuclide, you will have the Tc-99 much longer!)

Title: Re: Moly-99
Post by: Roll Tide on Jul 09, 2004, 03:14

Quote from: RadConSuper on Jul 09, 2004, 12:30

Could someone tell me what the dose rate from a 1130 Curie Moly-99 source would be.

Using 6CEN, I calculate 9221 R/hr at 1 foot. I haven't done too many of these lately, so double-check. If that is right, the doserate at 1 meter (40 inches) is 830 R/hr.

http://www.raymcginnis.net/Miscellaneous.aspx
results show 332,000 at 5 cm. This sounds like a good application for DU shielding. If I read it correctly, that is about 0.3 inches for a tenth-thickness given a ballpark 1 MeV decay energy.

I will need to be more awake to deal with the Tc-99 radioactive daughter! (Maybe one of the ALARA dudes on the site will sharpen up their sliderule and dazzle us!)

Title: Re: Moly-99
Post by: RadConSuper on Jul 12, 2004, 12:22

Thanks for the help Roll Tide.