Chapter 2 Safety
Mini-Switch LB 471
2.5 Radiation Protection Areas
Radiation protection areas define the boundaries around a radia-
tion source. The maximum dose rate defines the limit. We distin-
guish three radiation protection areas:
2.5.1 Exclusion Areas
Exclusion areas are areas in which the local dose rate may be ex-
ceed 3 Millisievert (mSv) per hour. These areas have to be pro-
tected such that nobody has unchecked access to these areas –
not even with single body parts. Actually, these areas can occur
only in the active beam in the direct vicinity of the shielding.
The radiation protection directives have to be observed.
Exclusion areas have to be protected such that nobody has un-
checked access to these areas – not even with single body parts.
This has to be ensured through constructive measures, for exam-
ple by protective covers.
2.5.2 Controlled Areas
Controlled areas are areas in which persons in one calendar year
may receive an effective dose of more than 6 mSv if they stay in
this area 40 hours a week and 50 weeks per calendar year. Based
on this, the calculated maximum dose rate is 3 µSv/h. These areas
should be planned such that accessibility is virtually not possible or
that the required safety fences can be installed easily. If con-
trolled areas are accessible they have to be secured. Moreo-
ver, they have to be identified clearly and permanently by a radia-
tion danger sign and the comment “Controlled Area”. Persons may
access controlled areas only to carry out maintenance work for the
operations going on inside this area (§ 37). Body doses have to be
calculated or personal doses have to be measured. The authorities
may permit exceptions from the demarcation and identification
duty, provided individuals or the general population are not en-
dangered. Higher limit values are admissible if reliable in-
formation is provided that the person affected stays within
the controlled area for a shorter period of time.
To Next Page
Loading...
