[ RadSafe ] U 238 BKG in US

[cobdw at tds.net]

To all,
I am in need of some information for a survey plan that I am developing. Can anyone point me in the right direction to determine the average background for U-238 in the southern California area? Specific area would be San Clemente. Additionally, can anyone point me in the right direction to obtain the cpm to microRem/hr ratio for a 3x3 NaI detector for the U-238 prodigy gamma emitters?

Thanks in advance,
D. Coble