~ 50 - the value selected by Kathren be used when.the RF is unknown to determine the ambient ground contamination standard. Apolying an RF=10-4 m+ to the ambient M2Ca standard recommended in the previous section, we obtain a maximum permissible surface contamination (MPSC) c of 9x10 -8 "7 2 uCi/me. ’ B6 level for hot particles . . 2 This is roughly 1 hot particle/m. In areas where an RF greater or less than 1074 ml could be shown to apoly, the MPSC could be altered aporopriately. E, As Low as Practicable Hearinc It is to be understcod that the abova recomtendations co not represent endorsement on our vart of the ris ct ct I innerent in the existing rad ation protec lon guidelines upon which these recommendations are basec. Rather, we offer }- tnese ‘3 Let) yn tha racticabls. Therefore, we guidelines Se incorporated 1-- recermend as Ltt Further ne cr spelow these guicel od tne admonition that the exposures should be kept as far mio the existing regulations without delay and that the limits for exnssure to not particles. 24, This value is derived as follows: The recammendad MPCa For not partistes is 9x190713 uci/ml which corressonds to 3x19712 uciyed. The maximum ground cancamination level, using pralo74 m4, is 9xlovl2y1o-4 = OxLlo-? utivn2. wee cepwee OR yt ay ER eee ne ke ern tee gen ene foPEE ele eT ee fe ag er gest ROR GS Mp ar a pee Om Vr ET ‘ .