CNSC Flashcards
what class does brachy fall into?
Class II nuclear facilities and prescribed equipment regulations
class II refers to brachytherapy remote afterloaders, and therapy linacs of various types (lower than 50 MeV for particles with <= 4 amu; lower than 15 MeV for particles with > 4 amu)
general requirements for class II nuclear facilities
o Door interlocks (no beam on when door open, beam off when door is opened) and last person out switch. Door should only lock from the outside (i.e., no one should ever be locked inside the room).
o Visual monitoring system.
o Source out of safe indicator.
o Independent radiation monitor which produces an audible alarm when someone enters the room while the beam is on, and which has an independent back up power supply.
o Emergency stop buttons throughout treatment room and at control console.
o A sign indicating 24 hour emergency contact.
o Device should be password/key protected so that only authorized personnel may operate the device.
o Following treatment, patients must be surveyed to ensure they are free of nuclear substances.
o A remote alarm system which detects and warns of any interruption in treatment.
o A shielded storage container for emergencies (e.g., when the source doesn’t retract).
o Remote handling tools necessary to recover the radioactive sources in an emergency.
o A radiation survey meter calibrated yearly with low battery indicator.
o Leak tests (wipe test) must be performed yearly (or at quarterly source change for e.g., Ir-192)
o A separate, locked storage room for storing old sources before they get shipped, and for new sources before they are installed.
ionizing radiation levels for exclusive use: limits for packages for transport
o 10 mSv/h on external surface of the package;
o 2 mSv/h on the surface of the conveyance (i.e., the vehicle, aircraft, etc.)
o 0.1 mSv/h at 2 m from the surface of the conveyance.
• Exclusive use means the sole use by a single consignor or a conveyance or of a large freight container.
limits for packages for transport for non-exclusive use
o 2 mSv/h on external surface of package (compare with 10 mSv/h for exclusive use)
o 0.1 mSv/h at 1 m from the package
o 2 mSv/h on the surface of the conveyance (same as for exclusive)
o 0.1 mSv/h at 2 m for surface of the conveyance (same as for exclusive)
typical background radiation
3 mSv/y (0.0003 mSv/h)
necessary markings for transport of radioactive source
• Necessary markings:
o Identification of either consignor or consignee, or both – need durable and legible marking
o Radiation trefoil symbol should be on outermost receptacle; should be water and fire resistant.
o Different types of shipping labels:
Category I white label with trefoil symbol giving list of radioactive components and the activity.
Category II or III yellow labels include transport index (TI)
how to calculate transport index
determine the max radiation level in mSv/h at 1 m distance from external surfaces of package. This value multiplied by 100 gives the TI. Values shall be rounded up to the first decimal place, except that values of 0.05 may be considered zero.
categorize I-white, II-yellow, III-yellow
o TI = 0 and max radiation level at any point on external surface <= 0.005 mSv/h I-white
o TI > 0 but <=1 and max radiation level at any point on external surface > 0.005 mSv/h but <= 0.5 mSv/h II-Yellow
o TI >1 but <=10 and max radiation level at any point on external surface > 0.5 mSv/h but <=2 mSv/h III-Yellow
o TI > 10 and max radiation level at any point on external surface > 2 mSv/h but <= 10 mSv/h III-Yellow, Must be transported under exclusive use.
• Where the TI satisfies the condition for one category but the surface radiation level satisfies the condition for a different category, assign it to the higher category.
what does LSA stand for?
low specific activity
what does SCO stand for
surface contaminated object
i.e., a solid object which is not itself radioactive but which has radioactive material distributed on its surface.
consigner vs consignee
consigneur is sender, consignee is receiver
what is UN number
as assigned by the United Nations Committee of Experts on the Transport of Dangerous Goods) – class “7” means some sort of radioactive material. A UN number is assigned in addition to the class in order to identify what type of radioactive material it is
-indicated with sticker with the 4 stars on it
what info does consigner have to include for transporting radioactive good?
- names and adresses of consigner and consignee
- UN number (7)
- radionuclides, their chemical form, and the max activity of the contents
- category I, II, or III
- transport index (for categories II and III only)
- certificate of approval from various relevent authorities
- specifify exclusive use if relevant
