105 CMR 120.649
Radiation Monitors
(A) Irradiators with automatic product conveyor systems must have a radiation monitor with
an audible alarm located to detect loose radioactive sources that are carried toward the product
exit. If the monitor detects a source, an alarm must sound and product conveyors must stop
automatically. The alarm must be capable of alerting an individual in the facility who is prepared
to summon assistance. Underwater irradiators in which the product moves within an enclosed
stationary tube are exempt from the requirements of 105 CMR 120.649(A).
(B) Underwater irradiators that are not in a shielded radiation room must have a radiation
monitor over the pool to detect abnormal radiation levels. The monitor must have an audible
alarm and a visible indicator at entrances to the personnel access barrier around the pool. The
audible alarm may have a manual shut-off. The alarm must be capable of alerting an individual
who is prepared to respond promptly.