Penn State University Radionuclide Safety Training. Environmental Health and Safety Radiation Protection 865-6391 Created by Russel O. Dunkelberger II, Revised Sept. 2004. 1. Introduction. Introduction.
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Environmental Health and Safety
Created by Russel O. Dunkelberger II, Revised Sept. 2004
N = number of neutrons
Z = atomic number = number of protons
X = elementNomenclature
1 Ci = 2.22 x 1012 dpm = 3.7 x 1010 Bq
1 Ci = 2,220,000 dpm = 37,000 Bq
A = A0e-t
A = Activity at time, t
A0 = Initial activity
= ln 2 / half-life
t = Elapsed time
Elapsed time, t # half-lives Activity
0 weeks 0 1 mCi
2 weeks 1 0.5 mCi
4 weeks 2 0.25 mCi
6 weeks 3 0.125 mCi
8 weeks 4 0.0625 mCi
From NRC Regulatory Guide 8.29:
(available at http://www.nrc.gov/NRC/RG/08/08-029.pdf)
From NRC Regulatory Guide 8.29:
Health Risk Estimate of Life Expectancy Lost
Smoking 1 pack cigarettes per day 6 years
Being 15% overweight 2 years
Alcohol consumption 1 year
Being in any accident 1 year
Natural hazards 7 days
Medical radiation 6 days
Occupational radiation exposure
300 mrem/year from age 18 to 65 15 days
1000 mrem/year from age 18 to 65 51 days
*Adapted from B.L. Cohen and I.S. Lee, “Catalog of Risks Extended and Updated,” Health Physics, Vol. 61, September 1991.
For a single exposure to extremely high levels of radiation (>50 rem), the following sequence of events may occur:
Ablation of bone marrow, death within months, if untreated
Desquamation of intestinal epithelium, death within weeks, if untreated
Unconsciousness within minutes, death within days, if untreated
Efficiency = cpm / dpm
dpm = cpm / Efficiency
If we detect 2,200 cpm of P-33 with a Pancake GM probe, we can determine the activity. The efficiency for P-33 with a Pancake GM probe is about 10 %.
dpm = 2,200 cpm / 0.10 = 22,000 dpm = 2.2 x 104 dpm
We already know that 1 Ci = 2.22 x 1012 dpm.
2.2 x 104 dpm x (1 Ci / 2.2 x 1012 dpm) = 1 x 10-8 Ci
1 x10-8 Ci x (106Ci / Ci) = 1 x10–2 Ci = 0.01 Ci
1. Stop the spread of radioactive material. If there is any sign of hallway contamination, run a rope across the hall at least 10 feet from the door on both sides of the lab. Use Caution signs and duct tape. Enforce the no-pass rule, station someone to stop traffic.
2. Warn others in laboratory. This will help minimize the spread of the contamination. Call EHS for assistance at 865-6391.
3. Survey all lab personnel. Record results (Fred left shoe: 10,000 cpm-GM at 1 cm, Betty palm of right hand: 950 cpm-GM at 1 cm). Pay particular attention to skin contamination. Skin dose may be a problem. Document levels prior to a quick clean, recheck/re-document.
4. Survey people in other labs if there is any indication of widespread problems. Instruct others to survey their own labs.
5. Call in Help. The laboratory supervisor should be present to organize the cleanup. The supervisor should call in all staff and students.
Request help for cleanup from EHS.
6. Determine if the chemical composition of the spill could cause airborne particulate contamination if the spill was allowed to dry. If so, mop immediately.
7. Establish a 'Clean' area. The area should be inside the room if possible, in the hallway if not. Issue boots or plastic bags for shoe covers. Absorbent bench paper is handy for covering floors to use as a clean area.
8. Survey public areas. Have someone with clean feet survey hall, elevator, stairs, etc.
If wider contamination is found, expand your roped
9. Survey the room. Remove people from lab until a survey of the room is performed. Smears are not necessary, but documentation is required.
10. Assign some lab personnel to cleaning the halls while others continue to survey. Extend roped off area as necessary. Do not permit lab personnel to decontaminate their own space until all public areas are clean. Radiation protection staff will not necessarily help perform the decontamination, but they will help train, supervise, and monitor.
1. Enforce glove changes whenever a glove gets contaminated.
2. Work from cleaner areas towards areas with more contamination.
3. Do not permit removal of contaminated shoes. People tend to contaminate their socks, then their feet. Have personnel place plastic bags over their shoes and walk carefully.
4. If the room has to be roped off and not used until the next day, NRC notification may be required.
1. Radioactive materials may only be possessed or used in accordance with authorizations issued by the University Isotopes Committee.
2. Persons working in radionuclide laboratories must be familiar with regulations and radiation safety procedures. New personnel must contact EHS to arrange for required safety instruction before beginning work with radioactive materials.
3. Orders for shipment of radioactive materials to and from the University and transfers between supervisors within the University must be processed through EHS.
4. Inventory forms for radioactive materials must be kept current. Completed inventory forms must be returned to EHS when the material has been used up or has decayed to an insignificant activity level.
5. People using radioactive materials are responsible for conducting routine surveys to detect excessive contamination or radiation levels each time unsealed radioactive materials are used.
6. People using radioactive materials are responsible for the immediate decontamination of facilities that become contaminated in excess of allowed levels.
7. Pipetting by mouth is prohibited in laboratories where unsealed radioactive materials are used.
8. Persons working with unsealed radioactive material must wear laboratory coats, or other protective clothing and appropriate protective gloves.
9. Eating, drinking, or the storage of food or beverages is prohibited in laboratories where unsealed radioactive materials are used. Radiation protection staff have been directed by the University Isotopes Committee to order the use of radioactive materials be stopped immediately in any laboratory in which food or drinks are found. Use of radioactive materials must not resume until the laboratory supervisor has taken action to correct the problem and has received written approval to start work from the University Isotopes Committee.
10. Radioactive materials must be discarded only into appropriately labeled radioactive waste containers. Radiation protection staff has been directed to order the use of radioactive materials stopped immediately in any laboratory in which radioactive material is found in normal trash, biohazard waste, or recycling containers. Radionuclide use may not resume until the laboratory supervisor has taken action to correct the problem and has received written approval to start work from the University Isotopes Committee.
11. All containers with greater than 1 Ci of radioactive material that are left unattended must be labeled with: the radiation caution symbol, the user’s name, the radionuclide, the activity and the date. Lead shields, cabinets, refrigerators and other storage areas for radioactive material must also be conspicuously labeled.
12. Licensed radioactive material in storage must be secure from unauthorized removal or access. Radioactive material not in storage must be controlled and under constant surveillance.