General Employee Radiological Training

(GERT)

TMS course ESH738

Argonne National Laboratory

ESH Division

Training Group

May 1999

COURSE OBJECTIVES

Upon completion of this program, you will be able to discuss the Argonne-East Radiological Control Program in regards to radiological terminology, hazards and risks, controls and identification systems, and employee responsibilities. You will be able to:

Identify fundamental radiological terms and concepts.

Identify natural and man-made sources of background radiation.

State the potential health effects of radiation exposure.

Compare risks due to occupational radiation exposure with other common health risks.

Identify the ALARA concept and practices.

State the methods used to recognize and control radiological hazards.

State management and individual responsibilities for the site radiological control program.

INTRODUCTION

General Employee Radiological Safety Training (GERT) is provided to all new employees and other site workers who may routinely enter Controlled Areas or encounter radiological barriers, postings or radioactive materials. Employee responsibilities for observing and obeying radiological control postings and procedures are emphasized throughout this training.

It is important to note that general employees will probably not be exposed to radiation or radioactive materials.
Additional training beyond GERT is required for employees who are identified as radiological workers.

1. TERMS AND CONCEPTS

There are certain fundamental terms and concepts used at radiological facilities to explain the nature of the work performed. As a worker at a DOE site, you should be familiar with these terms and concepts.

A. Radiological Terms

Ionizing radiation - radiation with enough energy to remove electrons from atoms. This type of radiation is of most concern to us.

rem - is the basic unit of ionizing radiation dose equivalent. It is usually expressed in smaller units called millirem (mrem):

1 rem = 1000 mrem

The rem and mrem measure biological damage or health risk to our bodies.

Radioactive material - any object containing unstable (radioactive) atoms which release ionizing radiation.

Radioactive contamination - radioactive material in an unwanted place. Usually in a dispersible form such as powder, dust or liquid which can be spread from one surface to another by casual contact. Also includes "fixed" contamination which has been embedded in another material.

B. Radiological Concepts

1. Atoms

The elements that make up all matter are composed of atoms. Each atom is made up of three major parts: protons, neutrons and electrons. The protons and neutrons are located in the center of the atom, called the nucleus. Electrons orbit the nucleus.

Stable atoms - Most atoms contain the proper ratio of neutrons to protons to be stable. They do not need to rid themselves of excess energy.

Unstable Atoms - Some atoms are not stable. Their ratio of neutrons to protons is too high or too low. They contain too much energy and therefore try to become stable by releasing their excess energy in the form of radiation. This energy release is classified as either ionizing or non-ionizing radiation.

atom

2. Ionizing radiation

The four basic types of ionizing radiation are:

- alpha particles

- beta particles

- neutron particles

- X-rays / gamma rays ( X-rays differ from gamma rays only in their origin)

3. Non-ionizing radiation - does not have enough energy to remove an electron from an atom. Even though non-ionizing radiation can cause biological damage, it is not a major radiological concern. Common types of non-ionizing radiation include: microwaves, radio waves, visible light, heat (infrared), magnetic fields and ultrasound.

4. Comparison - A common misunderstanding is that exposure to radiation can contaminate a person. Exposure to radiation does NOT result in contamination. Radiation is a type of energy. Contamination can only occur if a person comes in direct contact with a radioactive powder, dust or liquid; i.e. loose radioactive material.

2. BACKGROUND RADIATION

People have always been exposed to natural radiation. We are exposed to radiation from our environment and from within our bodies. The average person living in the U. S. receives a radiation dose of about 360 mrem every year. This comes as a combination of both natural and man-made sources of radiation.

background rad sources

A. Natural Background Radiation

This exposure is a result of cosmic rays (radiation from the sun and outer space), radioactivity in the earth's crust (rocks and soil), radon gas, and radioactive material present in our bodies (e.g. potassium) from our food and water.

B. Manufactured Sources of Radiation

These man-made sources include medical and dental use of X-rays, radio pharmaceuticals (radioactive drugs), consumer products (e.g. smoke detectors, lantern mantels, tobacco products, old vacuum tube televisions), transportation of radioactive materials and fallout from nuclear weapons testing.

C. Annual Radiation Dose from Selected Sources (mrem/year):

pie chart gif

Total of all manufactured and natural background sources: 360 mrem/year

3. HEALTH EFFECTS

A. Introduction

Our knowledge of radiation health effects is mainly from cases where very high doses of radiation were received over very short periods of time. For example, victims of the atomic bomb radiation in Japan and persons who received high doses of radiation for certain medical treatments.

B. Potential Health Effects to Exposed Individuals

Workers at radiological facilities who receive any radiation exposure tend to receive small amounts over long time periods. These are called chronic radiation doses. Our dose from natural background radiation, routine medical x-rays and occupational radiation are examples of chronic exposures. Persons who receive chronic radiation doses may increase their risk of cancer. The probability of cancer due to occupational radiation exposure is very small compared to the natural cancer death rate which is 20% of all deaths.

C. Future Children of Exposed Individuals

Radiation induced genetic disorders that are passed on to future generations are called heritable effects. These effects have been shown in carefully controlled experiments using plants and laboratory animals. Such experiments would not be conducted on humans. However, retrospective studies of humans who were exposed to high doses of radiation from medical therapy or atomic weapons have revealed NO heritable effects in their children. But, lack of observed effects does NOT mean that they are not possible. We assume that heritable effects can occur in humans but that the probability is low compared to the normal rate of genetic disorders.

D. Prenatal Radiation Exposure

pregnant woman photo

A developing embryo/fetus is especially sensitive to ionizing radiation. Radiation exposure to the embryo/fetus may increase the chances that the child will develop conditions such as:

- lower birth weight

- mental retardation

- stunted physical growth

- reduced IQ

These effects have been observed in humans (atomic bomb survivors) when the fetal radiation dose exceeded 15,000 mrem. These effects may also be caused by exposure to other toxic substances in our environment. Alcohol and tobacco products now warn pregnant women not to consume them for this reason. Although it has not been observed, it is also possible that prenatal radiation may increase the risk of childhood cancer.

E. DOE and Argonne Prenatal Radiation Policy

The risk of these effects is minimized by having special protective measures for pregnant radiological workers and by keeping all exposures as low as reasonably achievable. Argonne implements DOE prenatal radiation policy as follows:

The radiological worker is encouraged to voluntarily notify her supervisor of her pregnancy. She should also submit a "declaration of pregnancy" form to the Medical Department. Blank forms are available at the Medical Office in building 201 or can be printed from the ESH Manual chapter 5-23.
The worker will receive counseling from ESH Health Physics on prenatal radiation health effects.
The "declared pregnant" worker and her supervisor are encouraged to arrange for a mutually agreeable reassignment of work tasks (without loss of pay or promotional opportunity) such that occupational radiation exposure is unlikely.
Argonne's policy toward pregnant radiation workers is to limit the dose to the fetus/embryo as far below the DOE limit of 500 mrem as is reasonably achievable. An exposure control level of 50 mrem per month is also followed.

4. RISK COMPARISON

A. Radiation Dose Limits

The radiation dose limit for workers at DOE facilities is 5000 mrem/year, while for site visitors, minors, and the general public the legal limit is 100 mrem/year.

Workers who have the potential to receive above 100 mrem/year are required to complete Radiological Worker Training. Most workers at Argonne will receive less than 100 mrem/year. This GERT program is sufficient radiological training for most workers at Argonne.

B. Relative Risk Comparison

Let's compare the risk of working with or around sources of ionizing radiation versus other risks we accept as part of everyday life. Table 1 shows activities and their corresponding risks. If you partake in any of these listed items, you have one chance in a million of dying as a result. While some of the items like driving or flying are real risks, others are hypothetical risks. For example, no one really knows if smoking just a few cigarettes or receiving a few mrem of radiation carries any risk at all. We do know that these activities carry a measurable risk at high doses, such as smoking 100,000 cigarettes or receiving 100,000 mrem. It is prudent to minimize exposure to all risks.

.	Table 1 - Activities with 1 Chance in 1,000,000 of Dying
.	Smoking 1.4 cigarettes. (lung cancer)
.	Eating 40 tablespoons of peanut butter (aflatoxin poisoning)
.	Eating 100 charcoal broiled steaks (carcinogenic substances produced by grilling)
.	Spending 2 days in New York City (air pollution)
.	Driving 40 miles in a car (automobile accident)
.	Flying 2,500 miles in a commercial jet (crash)
.	Paddling a canoe for 6 miles (drowning)
.	Receiving 10 mrem radiation dose (cancer)
.	.

Table 2 presents several activities and the average lost life expectancy which occurs to a person who dies as a result. The number of days of life lost is calculated by measuring the days lost by a deceased person in the category of interest and then averaging these days over all persons who partake in the activity. Many people who partake in these activities will suffer no reduced life expectancy.

Table 2 - Average Loss of Life Expectancy

Activity

Days of Life Lost

Being an unmarried male

3500

Smoking 1 pack per day of cigarettes

2250

Being an unmarried female

1600

Employed as a coal miner

1100

Being 25% overweight

777

Alcohol abuse

365

Employed as a construction worker

227

Employed in general industry in U.S.

Radiation dose of 100 mrem/year for 70 years

Drinking coffee

C. Occupational exposure

The risks associated with occupational radiation exposures are very small and considered acceptable when compared to that of other accepted occupational risks. Here are the average annual radiation doses received by persons who work in various occupations

Table 3 - Average annual radiation dose by occupation

mrem/yr

Industrial radiographer

490

Airline flight crew member (elevated cosmic radiation)

350

Nuclear power plant worker

310

ANL-E radiation workers who have any measurable dose

125

Worker in Grand Central Station, NY (high background radiation)

120

Medical personnel (X-rays and nuclear medicine procedures)

DOE & DOE contractors

All ANL-E radiation workers

D. Benefit versus risk

Accepting risk is a personal matter and each individual must weigh the benefits against the potential risk. We know that there are many benefits from ionizing radiation. However, because it may harm us if we receive too much, just like taking too many aspirin can be fatal, we must learn to respect it and learn to work safely with and around radiation.

5. ALARA CONCEPT

The DOE and Argonne Lab are firmly committed to having a Radiological Control Program of the highest quality. Therefore, maintaining occupational exposures to radiation and radioactive materials As Low As Reasonably Achievable is an integral part of all site activities. This ALARA philosophy applies to our workers, visitors, persons living offsite, as well as the environment.

Three basic practices are used by workers to maintain their radiation exposures ALARA:

Time - Reduce the amount of time spent near a source of radiation.

Distance - Stay as far away from the radiation source as possible.

Shielding - Place some type of shielding between you and the source.

6. RADIOLOGICAL CONTROLS

In support of the ALARA concept, radiological controls have been established in order to protect individuals from exposure to radiation and radioactive material.

Rad Tech survey photo

A. Area Monitoring

Since radiation cannot be detected with any of the human senses, special detection devices must be used. The Health Physics section of ESH Division routinely measures radiation and contamination levels in all areas of the Argonne site. Locations where radiological conditions exist are clearly posted, and radioactive materials are labeled to indicate the hazard. There are other methods used to help you identify radiological hazards.

B. Hazard Identification

Here are examples of methods used to identify and control radiological hazards:

	Areas which contain radiological hazards are posted at the access point.
	Signs, labels and tags with the trefoil radiation symbol colored magenta or black on a yellow background are used to mark areas and objects.	Warning lights may be used to indicate a radiological hazard.
Workers wear lab coats and gloves in areas where radioactive liquids and powders are used.			Yellow and magenta rope, tape, chains or other barriers are often used to designate the boundaries of posted areas.
	Alarms may warn of an abnormal radiological condition.	The general response to alarms is:
		STOP what you are doing.
		EXIT the area.
		NOTIFY the proper authority.

C. Radiological Postings

Postings (signs) are used to alert you of a potential or known radiological hazard and to aid you in minimizing exposures and preventing the spread of contamination. All radiological postings used at ANL are similar to the example below:

CAUTION		All radiological postings include a warning a the top. Usually "CAUTION" is indicated.
		The radiation trefoil or "propeller" symbol is always included.
CONTROLLED AREA		The words, "CONTROLLED AREA" are always used on radiological postings at Argonne.
RADIOACTIVE MATERIAL		This space displays the radiological area designation which applies for this specific area.
Entry Requirements:		Entry Requirements are always listed.
- NO EATING, DRINKING		Controlled areas forbid eating and drinking. Do not smoke, chew gum or tobacco, apply cosmetics, etc.
- TLD REQUIRED		Any other requirements for the area are indicated. In this case, you must wear your thermoluminescence dosimetry (TLD) radiation badge.
Dose rate at this sign: 10 microrem/hr JGB 5/26/99		The last item gives the radiation dose rate measured at this sign. Normal background radiation is 5-20 microrem/hr. If the measured rate is higher, you should practice ALARA and move to a low background area.

Persons who have GERT training are NOT allowed to make unescorted access to any areas posted with a RADIOLOGICAL AREA DESIGNATION, like in the example above. The common designations are: "Radioactive Material", "Radiological Buffer Area", "Radiation Area", "High Radiation Area","Contamination Area", "Airborne Radioactivity". Some areas may have a posting similar to the sample above, but the radiological area designation field is blank. This indicates that the radiological hazard potential is very low. Occasional access to such areas should not result in a dose above 100 mrem/year. Persons who have completed GERT level training are allowed to access such areas without an escort.

D. Radiation Dosimeters

TLD badge photo

Workers who may receive a dose of at least 100 mrem/yr are issued a radiation dosimeter (also called a TLD badge). About 2500 people are issued TLD badges at Argonne each year. However, only about 10% of these badged workers receive any measurable radiation dose. The average dose to the workers with measurable dose is about 100 mrem/year. TLD badges do not protect you from radiation. They simply monitor your radiation dose.

APS TLD photo

Standard Argonne TLD Badge

TLD Badge Used at APS

E. Other Controls

Your work area may have unique hazards, controls, warnings and emergency response procedures. Your supervisor will arrange for area specific training, typically included in your building safety orientation.

7. RESPONSIBILITIES

A. Management Responsibilities

The management of Argonne National Lab is responsible to establish an effective ALARA program. Some of the ways this has been implemented includes:

- Establish radiation exposure administrative control levels and annual ALARA goals.

- Solicit feedback from the workforce on improvements to the radiological control program.

- Implement policies and procedures to maintain radiation exposures ALARA.

- Hold workers accountable for radiological performance.

B. Your Responsibilities

- Obey all signs and postings and comply with all radiological safety rules and procedures.

- Do not enter any posted controlled area which includes a radiological area designation, unless you are escorted by a radiological worker who is familiar with the area.

- If accessing a radiological area with an escort, you must obey his or her instructions, wear any required radiation dosimeter and practice ALARA to minimize your exposure.

- Know how to contact the Health Physics group for your work area.

- Be alert for and respond to any unusual radiological condition.

- At some locations, you may be required to monitor yourself for radioactive contamination. Follow the directions for use posted on the Hand and Shoe Monitor. Or, ask an experienced worker or Health Physics personnel to show you.

If you get a positive indication of contamination:

- Stay in the immediate area.

- Call Health Physics or have some else call.

- Wait for help to arrive.

hand shoe monitor

Questions? Email: Steve Butala - ESH Training Group: sbutala@anl.gov