Section 144-220-I-12 - Ventilation systemsA. 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 Part D, Appendix A, Table I of this rule.B. A licensee, as required by Part D.7 of this rule, shall not vent, release or otherwise discharge airborne radioactive material to an unrestricted area which exceed the limits specified in Part D, Appendix A, Table II of this rule, except as authorized pursuant to D.17, or D.7.B of this rule. For purposes of I.12.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.10-144 C.M.R. ch. 220, § I-12