Section 120.711 - Ventilation Systems(A) Ventilation systems shall be provided to ensure that personnel entering any area where airborne radioactivity may be produced will not be exposed to airborne radioactive material in excess of those limits specified in 120.296: Appendix B, Table I.(B) A registrant, as required by 105 CMR 120.221, shall not vent, release, or otherwise discharge airborne radioactive material to an unrestricted area which exceeds the limits specified in 105 CMR 120.296: Appendix B, Table II, except as authorized pursuant to 105 CMR 120.221(A)(3) or 120.222(C). For purposes of 105 CMR 120.711(B), concentrations may be averaged over a period not greater than one year. Every effort should be made to maintain releases of radioactive material to unrestricted areas as far below these limits as is reasonably achievable.