The Radiation Safety staff is responsible for ensuring the
safety of individuals using ionizing radiation (radioactive materials and
radiation-producing machines) at the UNM campus and in other locations where
these items may be used by University faculty and staff. Our objective is the
protection of people and the environment from unnecessary exposure to radiation.
We accomplish this by providing a radiation protection program to the University
community which is in compliance with both Federal and State Radiation
Obtaining Radioactive Materials
Radioactive materials are used in medical diagnosis, therapy and research in humans, human research subjects, research and development, animal studies, student instruction, shielding and instrument calibration in UNM facilities, and at temporary job sites within the State (not under exclusive Federal jurisdiction) as approved by the Radiation Safety Committee.
The UNM Radioactive Material License and the UNM Radiation Safety Manual must be followed in regard to radioactive materials and other sources of ionizing radiation.
Each individual or group who wishes to initiate a program that has radiological implications shall submit a written proposal to the Radiation Safety Division. All uses of ionizing radiation and radioactive materials must be performed under the authority of a Radiation Permit. The acquisition of radioactive material shall not be permitted until approvals have been received. The initiator of the proposal sends the application for a permit form RSF-01-1 to the Radiation Safety Officer for review. If the RCC (Radiation Control Committee) approves an application, a permit is issued. All users of ionizing radiation must submit a completed T&E (Training and Experience) Form to the Radiation Safety Division. Certain specific medical groups are exempt from this requirement.
All purchases of radioactive materials must be done with the prior approval of the Radiation Safety Division. The Radiation Safety Division is to be called prior to purchasing radioactive material. The items to be purchased should be identified and Radiation Safety will check the permit holder’s current inventory of radioactive materials and will give the caller an “authorization code” if appropriate. This code must be provided to the vendor when the material is purchased. The vendor must be instructed to include Radiation Safety authorization code on all packing slips. ALL radioactive material packages are sent directly to the Radiation Safety Division unless special arrangements are made with the Radiation Safety Office prior to delivery. The Radiation Safety Division will deliver the materials to the location specified on the same day that the package is received unless otherwise communicated.
Tracking of Radioactive Materials
The Radiation Safety Division currently uses a software program called Environmental Health & Safety Assistant (EHSA) to track all Radioactive Material (RAM) inventory at UNM. The Technicians at Radiation Safety enter all the information into the database and the Health Physicist at Radiation Safety performs the final review/approval of the database. From initial receipt to final disposal, all RAM is tracked by receipt date, activity, location and user. HPA allows the Radiation Safety Division to provide users with current information on all packages received by the Division. Current inventories of each permit holder authorized to use radioactive material at the University under the State of New Mexico Radioactive Materials license can be obtained from the Radiation Safety Division upon request. Quarterly statements are distributed to each permit holder at the end of each quarter to verify their inventories. The permit holder is responsible for determining if the actual inventory for the permit is in agreement with the inventory kept by the Radiation Safety Division.
Pickup of Radioactive Materials
Radioactive waste generated on campus is not to be discarded into the regular sanitary waste disposal system. Specific rules, regulations and guidelines must be followed for the disposal of radioactive waste. Emphasis is placed on segregation of different types of waste according to radionuclide, half-life, chemical form, physical form, or combination thereof. Radioactive waste with a half-life shorter than 90 days can be held for decay under the decay-in-storage program and safely disposed of as non-radioactive waste once the radioactivity levels have become indistinguishable from background levels. Radioactive waste for decay-in-storage must be held for a minimum of ten (10) half-lives. For a material with a half life of 90 days – multiply the 90 days times 10 for a total of at least 900 days in storage before the material could be considered for testing to see if it is fully decayed. All other radioactive waste is collected and packaged for disposal to an outside licensed disposal facility. Waste pickups are decayed to the original receipt date, not the date of pickup.
The Radiation Safety Division picks up all radioactive waste from the
locations in the UNM Departments where it is being utilized. Waste is only
accepted in radioactive containers supplied or authorized by the UNM Radiation
Safety Division. The Departments call the Main Radiaition Safety phone line
and request a waste pickup. A member of the Radiaition Safety department will
key the information into the Rdiation Safety database. Most waste is picked up
by a Radiation Safety Environmental Health & Safety Technician 3 the following
day. The average time spent by the Radiation Safety staff for a waste pickup
from start to finish is approximately two (2) hours. The time to complete a
waste pickup can be longer if more than six cans are picked up or the pickup
involves anything other than what can be contained in a 5 gallon can. Radiation Safety instructs lab personnel to limit the number of containers because the radiation technician has to transport the containers from the lab to SRS vehicles and an effort is made to minimize the number of trips needed.
When picking up radioactive waste from the various locations across the UNM
Campus – the following procedures are followed. The technicians will pull the
request information from the database. They then print out an inventory of the
permit holder of the requesting location so they can verify for accuracy the
information provided by the department as to what is in the waste containers.
They then prepare replacement waste containers for the ones they are scheduled
to pick up. The technicians drive to the lab and pick up the waste, record the
information on the Radiation Safety waste forms and have the lab personnel sign off on the pickup. The material is then brought back to
Radiation Safety, visually inspected to make sure no hidden items may have
been placed into the waste containers, segregated and packed into drums based
on its physical form and half life. The technician then enters the information
into an Excel database to calculate the decayed amount of material that was
picked up. They enter this information on the waste form, drum log and into
the Radiation Safety radiation work log book. The form is then given to the
Health Physicist to check the technician’s calculations. If the calculations
are correct, the Health Physicist then enters the information into the
Radiation Safety radiation database. Lastly, the Health Physicist files the
completed form in the Radiation Safety file cabinets. The technician then does
a survey of the containers that were picked up to make sure there is no
external contamination on the containers they picked up and enter this
information on the Radiation Safety counting logs.
There are several waste categories (which are all described in the following paragraphs). If more than one waste category exists in a laboratory, the waste containers need to be specifically marked as to which type of waste is placed in each container. The different categories of waste must not be mixed together in each container.
- Solid dry waste. This normally consists of absorbent pads, gloves, disposable labware, pipettes and other similar items contaminated with radioactive material.
- Aqueous liquid waste. This denotes any waste of which the primary solution is water and any soluble organic and inorganic constituents, all present in quantities and forms that do not result in phase separation or precipitation.
- Liquid scintillation waste. This is liquid waste, which usually consists of a combustible based scintillation fluid.
- Biological waste. This primarily consists of animal carcasses, bedding and excrement. It may also include specimens in vials or containers.
- Mixed waste. This contains radioactive material and one or more hazardous chemical components. Hazardous waste contractors will not accept a hazardous waste that contains radioactive material. Any waste stream that involves the mixing of a hazardous waste with radioactive material must have prior approval from the Radiation Safety Division before generation.
- Uranyl/Thorium Compounds and Staining Solutions. Dry Uranyl Acetate, Uranyl Nitrate, Thorium Nitrate and solutions containing concentration of these shall be collected and disposed of as radioactive waste.
- Chelating Agents. The presence of high concentrations of chelating agents in radioactive waste may have an effect on waste-site stability.
The dry waste and biological waste is picked up from the departments in 5 gallon size buckets and is then emptied into larger drums. It is noted that some dry waste is received in 30 gallon size containers from the departments. Sharps containers are also picked up from the departments. Liquid waste is received from the departments in 1 gallon size containers and are transported within a 5 gallon size bucket to ensure there are no spills/leakage.
Shipment of Radioactive Materials
All outgoing radioactive material shipments must be processed or authorized by the Radiation Safety Division. Records of each shipment to an outside agency must be maintained. It is the responsibility of the Radiation Safety Division to assure that shipments are packaged and labeled in accordance with regulations and that the consignee is licensed to receive the shipment.
When radioactive waste is put in storage at the Radiation Safety Division storage area – the holding time starts for the decay in storage. If the half life of the isotope is greater than 90 days, the Radiation Safety Division will typically wait to ship these to an offsite radioactive waste disposal site until they have accumulated at least 10-20 drums for shipments. The drums range in size from 15-55 gallons. Shipments have been typically sent out every 3 to 4 years because of the transportation and handling cost of shipping these items. There are several fees and regulations involved in the disposal of the radioactive waste – including the cost of labeling, manifest, and transportation as well as the disposal cost per container charged by the contractor. UNM currently ships the waste to several places depending what the material is via the use of a broker.
Billing of Radioactive Materials
>Waste Manifests generated from the Environmental Health & Safety Assistance (EHSA) system can be used in the tracking of the collection and subsequent billing of UNM Departments for shipments of radioactive materials. Deposits should be obtained on an annual basis from the Main and HSC Campuses based on estimates provided by the Safety & Risk Services Division for the amount of waste to be shipped at a future date. The Finance Manager for SRS along with personnel from the Radiation Safety Division will develop these estimates and charge the fees for said waste disposal to the respective campuses via journal entry. The deposits will be accumulated in the General Ledger liability account code L3J1 - Deposits and Funds Held for Others. When the shipment occurs, the deposit amounts will be applied to the total invoice amount and then either: 1) refunded to the respective campuses if the deposit is in excess of the actual invoice cost or 2) an additional charge to the respective campuses will occur if the amount on deposit does not cover the actual amount of the invoice.