002 Radiation Surveys

Identify conditions which require immediate notification of a supervisor.

• Dose rates greater than site limit outside the RCA.

• Radioactive material found outside the RCA.

• Changing conditions require posting or RWP changes.

If counts above background are identified on a Large Area Smear the following actions can be taken.

• Resurvey the area until no activity is detected.

• Take disc smears to determine where decontamination is needed.

Identify ALL true statements concerning Alpha Level 2 areas.

• > 20 dpm Alpha

• Beta/Gamma to Alpha Ratio 30,000 to 300

Identify ALL true statements concerning survey documentation.

• Beta dose rates are recorded with a "B" for true beat dose rates.

(OW-CW) X BCF

• Neutron dose rates are recorded with a "N".

• Contact dose rates are recorded with an asterisks.

When are beta dose rates required to be measured?

Contamination levels exceed 500,000 dpm/100 cm2

The GM pancake probe frisker is used for the following.

• Measuring low level beta/gamma contamination.

• Used to release tools and equipment from a Contaminated Area.

How may a smear be measured if the GM Pancake frisker is off scale.

• Ion Chamber (OW-CW) x BCF = mrad/hr/100cm2

• Ion Chamber open window reading times site conversion factor for mr/hr to dpm.

Identify ALL true statements concerning Alpha Level 3 areas.

• > 20 dpm Alpha

• Beta/Gamma to Alpha Ratio <300 : 1

What are ALL the requirements for counting Alpha smears?

• > 100,000 dpm/100cm² in Alpha Level 1

• >20,000 dpm/100cm² in Alpha Level 2

• 50% of smears in Alpha Level 3

Survey DRPs using an open and closed window ion chamber. Identify all true statements.

• If open to close window ratio is <10, the DRP is a fuel particle.

• If open to close window ratio is >30, the DRP is a corrosion product particle.

Identify ALL requirements for DRP surveys.

• If count rate exceeds 50,000 ncpm determine if cause is DRP.

• Use tacky material or cloth to survey for DRP when contamination levels exceed 100,000 dpm/100cm2

Identify ALL true statements concerning radiation surveys.

• Select instrument to minimize dose during survey.

• If entering area of unknown dose rates, use the highest anticipated scale.

Identify ALL true statements concerning Contact dose rates.

• Dose rate taken in contact with source.

• Used to determine need for extremity dosimetry.

Identify ALL true statements concerning survey documentation.

• Air samples locations are recorded with a triangle.

• Smear locations are recorded with a number in a circle.

• Gamma dose rates are recorded with just the number.

Identify ALL true statements concerning Large Area Smears.

• Wipe area >5 times surface area of wipe.

• Measure large area smear in an area of <200 cpm background.

Alpha contamination may be measured using the following instruments.

• Gas flow proportional counter.

• ZnS scintillation detector

Identify ALL true statements concerning General Area dose rates.

• Dose rate taken 30 cm from source or surface that radiation penetrates.

• Used for posting of RA, HRA and LHRA.

Identify ALL true statements concerning contamination instrument background.

• Maximum background for a GM Pancake detector is 200 cpm.

• Maximum background for an alpha frisker is site specific to meet MDA < 20 dpm.

Identify ALL requirements for surveying greater than 7 feet above the floor.

• Survey if ladders, scaffolds or platforms allow access.

• Place survey tag at base of ladder, if access is allowed without prejob survey.

Identify ALL requirements for dose rate gradient surveys.

• Taken if dose rates exceed 100 mr/hr between the knees and head.

• Measure dose rates at head, chest, waist and knees.

Identify ALL true statements concerning Alpha Level 1 areas.

• < 20 dpm Alpha

• Beta/Gamma to Alpha Ratio >30,000 : 1

Alpha frisking is required when working in an area with beta/gamma to alpha ratios of:

< 50

What is the purpose of Area Radiation Monitors?

• Identify changing or abnormal dose rates

• Identify background dose rates in an area.

The Ion Chamber is used for the following.

• Measuring beta/gamma dose rates.

• Measuring high level beta/gamma contamination.