Do you have a question relating to radiation protection ? Email RPToday @ srp-uk . org or post on the general discussion area on the SRP forums ( member access only ).
A recent forum question concerned finding a copy of NRPB DL2 , long out of print . It ' s full name is Derived Limits for Surface Contamination by A D Wrixon et al . Written in 1979 it uses dose limits , annual limits and DAC values from ICRP26 to derive the action levels we commonly use for surface contamination for active areas , for surfaces of the skin and clean areas for various
-2 radionuclides ( i . e . 0.4 Bq cm alpha and 4 Bq
-2 cm beta ). Derived levels for the nuclear industry are based on the most restrictive radionuclides from a dose perspective such as Pu-239 or Sr-90 and this revision of the document expands the derived levels to include less restrictive radionuclides from non-nuclear uses of radioactivity such as factories , hospitals and universities .
NRPB DL2 provides all the calculations and assumptions on how the common surface contamination criteria were derived and how they relate to dose .
It is a great foundational text for anyone wishing to understand where the contamination criteria we commonly use come from . Unfortunately , since the document is now dated , the dose limits , ALIs and DAC values are from ICRP26 , and not ICRP60 / 103 . The document therefore needs to be read through a lens of new values and also new standards . But it is still useful for understanding - and the good news is we found it ( thanks Tony Wrixon !).
NRPB DL2 is available on the forum ( member access only ) or email RPToday @ srp-uk . org
14 Radiation Protection Today www . srp-rpt . uk