4 RAD WASTE CONTAINERS 30 gal. Fiber drum 5 gal plastic 2.5 gal carboy (CRS )30 gal. Fiber drum(CRS )LINERS!5 gal plasticbucket
5 ALARA FOR RAM STORAGE AREAS The primary factors associated with RAM storage areas are distance and shielding. No one should spend time around RAM storage areas. Where you place your RAM and RAD waste is essential in keeping doses ALARAIf an ideal place is not suitable, then shielding should be implemented. Secondary containment should always be used.
9 RADIOACTIVE STORAGE CONSIDERSTIONS WEAK BETAS –( 3H, 14C, 33P, 35 S) STORAGE IN ORIGINAL PIG, & SECONDARY CONTAINMENTSTRONG BETAS – (32P) STORAGE IN ORIGINAL PIG, INSIDE LUCITE OR PLASTIC CONTAINER, SOMETIMES LEAD SHIELDING OUTSIDEALL GAMMAS STORAGE IN ORIGINAL LEAD PIG, SECONDARY CONTAINMENT, EXTRA LEAD SHIELDING
10 “Summary of Isotope Inventory” up to date at all times Know where your RAM is at all times !Utilize proper and accurate inventorycontrols.Keep this form,“Summary of Isotope Inventory” up to date at all times
11 State Requirements for Storage and Control of Licensed or Registered Sources of Radiation Must be secured to prevent unauthorized removal or access in unrestricted areas. Under Lock and Key is ideal. If not, area access doors locked, or constant surveillanceShall control and maintain constant surveillance if in an unrestricted area.
12 Radioactive Materials Security .03(10) lists SECURITY requirementsRecent incidents in this country and other states have prompted the NRC to increase security requirementsAll sources of radiation must be secured against theft or use by unauthorized individuals - CHECK SECURITY IN YOUR LAB !!
14 exposure rate in milliRoentgen per hour Survey InstrumentsPortable and hand-heldDirect, real time and immediate measurementsHow the survey instrument was calibrated will decide what it is measuring. Look closely at the calibration information.Measure:exposure rate in milliRoentgen per hourmR/hr
15 Selection of a Survey Instrument What type of radiation does the instrument detect?Some instruments detect more than one type of radiationIt is critical to use an instrument appropriate for the radiation of concernShow each instrument and briefly describe each. Do not get into great detail.G-M: can respond to , and : and ; or only depending on the tube/window wall thicknessThin windowed probes required to pick up weak Betas like C-14
16 Recommended Survey Instrument Ludlum model 3 instrument (Part No ) with a meter dial and extra cableExplain that we can service these instruments. We will not guarantee service or calibration on any other instruments. Show the instrument and the meter dial.
17 Recommended Survey Probes Ludlum model 44-9 (Part No ) Alpha, Beta, Gamma pancake probeGeneral PurposeLudlum model 44-3 (Part No ) Gamma probeLow Energy Gamma (10-60 keV, Iodine)Ludlum model 44-2 (Part No ) Gamma probeHigh Energy GammaShow each of these probes. Demonstrate the backgrounds for each. Compare the thin crystal background and take the Am-241 check source and demonstrate that this is what your body might sound like if it was a thin crystal probe.Demonstrate the pancake probe using a mantle lantern. What type of radiation are we seeing? Put a piece of paper over mantle. Does the count rate go down? May not hear the rate decrease, but should see the meter reading decrease. Relate this to detection sensitivities between monitoring clicks and static count. Place alpha probe on paper covered mantle. Remove paper and demonstrate shielding for alphas. Pull alpha probe away from mantle and demonstrate how far alphas go in air and how you can determine if alphas are present using the pancake and distance. Place the pancake back on the mantle and pull away to see how the rate changes with distance. Relate this to the radiation (alpha, beta, gamma). How can we shield for betas? Place a plastic cover over the pancake probe and measure the mantle. The count rate should go down because of the betas being shielded. What effect would placing plastic or parafilm over the probe have? Do we have gammas? Turn the probe over and measure through the back. The count rate should be above background but much lower. These may be gammas, but it may also be bremstrahlung created in the metal backing. Use the Co-60 check source to demonstrate high energy gammas. Use the pancake and the Am-241 check source. Wave the pancake over the source very fast and then slow down to demonstrate survey speed. Use the thin crystal and demonstrate how much more efficient it is at picking up the low energy photon from Am by waving it over the Am-241 source in the same manner as was illustrated with the pancake. Which one would you rather use for low energy photons? Use the thin crystal and measure the Co-60 source and then use the 1x1 NaI to measure the Co-60 source. Discuss the differences between the size of the crystals in the probes and the window on the thin crystal allowing low energy photons to enter easily. The thin crystal does respond to the Co-60.
18 What Can The Instrument Detect? Can the instrument detect tritium?Can there be contamination that the instrument cannot detect?There is an instrument to detect tritium, but it needs a gas cylinder, a smooth surface and does not work well in vertical surfaces because the gas does not distribute evenly through the probe.There may be contamination that is below the detection limit of the instrument for all nuclides that can be detected using wipe tests.
19 Sensitivity and Energy Response Sensitivity – how does the instrument respond to the level of radiationEnergy Response – response of instrument may depend on the energy of the radiationSome instruments over-respond or under-respond to different radiation energiesDiscuss sensitivity. CSU calibrates the low scales because we expect these to be the scales used most. Show them a calibration label and read that at the x1000 scale it responds low. If we were in high levels we would calibrate the high scales.Discuss the calibrations that CSU performs for different nuclides.Take the Cl-36 check source and have one individual hold the probe at the required distance (see calibration information on the instrument) have another individual read the count rate. Calculate the activity and discuss how this can be used to determine activities of spills.Try to calibrate the instrument relative to the nuclide of interest.
20 Time Constant and Survey Speed Slow setting (s) reduced meter fluctuations, but requires more time to stabilizeFast setting (f) increases meter fluctuations, but requires less time to stabilize and gives faster readingsDoes not change the audible signalShow switch and demonstrate using a source. Show reset button and how to use it.Demonstrate survey speed.Survey SpeedBasic speed is 1 detector width per second as close to the source as possible without touching the source
21 High background may indicate: What is the background?High background may indicate:Radiation Field above backgroundLight Leak in ProbeHumidity ProblemsContaminated InstrumentIncorrect High VoltageNot Warmed UpIntermittent Cable Connection (short)No Background then Malfunction (Maybe OK for Probe)Show the alpha probe and the thin window. Holes in the window increase background. GM detectors with holes will continuously alarm once the gas has escaped.Humidity may short electronics.How do you know if the instrument is contaminated? Wipe test or survey with backup instrument. Must have backup in case the primary instrument is out for calibration and to check for contamination of other instruments. To clean, do not immerse in water. Take a wet towel or cloth and clean the instrument. The RCO will not pick up and calibrate contaminated instruments.High voltage discussed on next slide.Old instruments some times need to warm up. Read instruction manual.Order second cable and replace. Show that at connections it can break and work occasionally. The RCO will fix cables.
22 CalibrationSurvey Instruments subjected to hard use can go out of calibrationCalibration information is attached to the instrument and is part of your lab recordsCalibrate to the nuclide of interest if possibleGo over calibration information on the sticker. Take an end window GM and have an individual measure a Cs-137 check source. Record the measurement on the board. Take a pancake and have an individual measure the same source. Record the measurement on the board. Why are they so different? When an individual reports to the RCO in CPM what does it mean? Use the calibration factor on each instrument and calculate the exposure rate. Are they comparable? If they are still not close? Ask what the definition of exposure is. The Cs-137 gives off betas. This is not what the definition of exposure is. Take measurements again through the side of the end window and through the back of the pancake. The exposures should be very close. Now the measurements are comparable. Tell the individuals that they can take the measurements through the window because it will calculate a higher exposure and this works towards ALARA. Use the highest exposure measured and calculate the time to receive 5 rem (assume 1 R = 1 rem) from the source. Remember that the hands can get 50 rem (10 x more time). This is an overestimate.Discuss pulse generator calibration.Explain situations that happened at large irradiators where individuals entered a facility because a GM read 0. Individuals died and/or had major amputations because the source was exposed.Some instruments under respond at high exposures – some GM instruments read 0 and some read off scale. What does the instruction manual say?
23 Calibration Frequency UGA performs calibrations at least annuallyInstrument in calibration if performed within one yearFor extreme conditions increase frequencyBriefly discussImmediately after performance failureAfter any maintenance or repair (not including battery change)
24 Check Sources Specific procedures for check source placement Long half-life to minimize correction for decayNo impurities (134Cs, 137Cs)Chemically stableDurable with handlingCross check with another instrumentContact RSO for check sourcesShow different check sources.
25 Conducting a Performance Check Check for in service calibration stickerCheck battery using battery check positionCheck for any physical damage to meter or probeMeasure Background and compare to previous bkg historyMeasure response to check sourceDoes speaker work?Use instrument with corresponding QA/QC and perform a daily check. Have individual perform a check without telling them how to position the source. They should be off of the chart. Tell them to do the check again, but this time tell them how to position the source. Stress the importance of describing how the source is positioned.
26 Failure of a Performance Check DO NOT USE METER !Use a back up meter or borrow oneRemove instrument from use and contact the RSO for assistance. Your meter will need maintenance or repair and recalibrationBriefly discuss.
27 Liquid Scintillation Counting Set wipe counting protocol to full scale, 1000 channels ( 2000 KeV) Eliminate counting geometry variables Do IPC Know your typical background countrate?Use biodegradable LSF (Cocktail)Count BKG before and after sample set.Dark adapt samples including background Save all counting printouts
29 Radiation Surveys .03(7) requires radiation surveys and monitoring Chapter 6 of the 2003 UGA Radiation Safety Manual covers Radiation Surveys
30 Radiation Monitoring and Surveys Measurements of radiation AND contamination to evaluate the radiation hazardContamination is any radioactive material that is in any location where it is not desired.Surveys are conducted for restricted and non-restricted working areas and areas surrounding a facility.Hand and Foot or Whole Body surveys are recommended when leaving the radiation use laboratory.How many of you survey outside of your work area? This is what the RCO provides for you to meet the CSU license requirements.
31 State Rules for Surveying and Monitoring Must evaluate:Radiation levelsConcentrations or Quantities of Radioactive MaterialPotential Radiological HazardsStress the importance of potential hazards.
32 CONTAMINATION SURVEYS The primary purpose of contamination surveys are to identify the quantity (or verify the absence) of radioactive contamination on surfaces. The objective is to prevent the inhalation, ingestion, or absorption of radioactive contamination by personnel and to ensure that contamination is not spread to the surrounding environment.
33 TYPES OF CONTAMINATION SURVEYS Direct Scan Survey – use of the direct scan technique to measure the activity emitted from a surface. The radiation detected is the total result of any fixed and transferable contamination on the surface, and of any radiation that may be penetrating through the surface or emanating from another source.
34 TYPES OF CONTAMINATION SURVEYS Transferable Contamination Survey – An assessment of the amount of readily removable contamination present on a surface. A collection medium is used to wipe a surface while applying moderate pressure. The amount of activity detected on the collection medium is then determined using radiological instrumentation.
35 TYPES OF CONTAMINATION SURVEYS 100 cm2 Wipe Testswipe survey – the use of a collection medium (paper disc or equivalent) to cover approximately 100 square centimeters of surface area in the assessment of transferable contamination.
36 Standard industry practice 100 cm2 Wipe TestsStandard industry practice 100 cm2100 cm212” to 14”Show the size of filter paper to use and demonstrate an s-wipe. Talk about areas to wipe test and how to keep from spreading contamination. Talk about wipe test areas and to include them on the wipe test forms.4” x 4”
37 TYPES OF CONTAMINATION SURVEYS Large Area Wipe Survey – the use of a collection medium ( paper towel, disposable wipe, or equivalent) to perform a transferable contamination survey of a surface area significantly larger than 100 square centimeters.
38 TYPES OF CONTAMINATION SURVEYS Large Area Wipe Survey for Floors Masslin MopsSwiffers
39 TYPES OF CONTAMINATION SURVEYS Hand and foot Survey when exiting the rad work area
40 Glove ProtocolsSurvey your gloves at times while wearing them to reduce the spread of contamination
41 Know how to remove your gloves without touching your skin or clothing! Glove ProtocolsKnow how to remove your gloves without touching your skin or clothing!
42 LSC standard wipe counting efficiency = 0.33 Correction Factor = 3 CPM to DPM Conversion Using the Standardized LSC Wipe Counting EfficiencyLSC standard wipe counting efficiency = 0.33Correction Factor = 3Net cpm to equal 200 dpm = 67 cpmNet cpm to equal 1000 dpm = 333 cpmTherefore; CPM from printout x CF = DPMCPM X 3 = DPMFor wipe tests with whatever Isotope
43 Transferable Contamination ALARA Action Levels Unrestricted Area = 200 dpm/100cm2 (<66 cpm/wipe)Restricted Area = 1000 dpm/100cm2 (<333 cpm/wipe)Free Release Transferable Contamination ALARA Action Levels200 dpm/100cm2 (<66 cpm/wipe)
44 Types of Radiation Surveys On Contact The primary purpose of radiation surveys are to identify the magnitude (or verify the absence) of dose rates so that personnel exposure to radiation is maintained As Low As Reasonably Achievable (ALARA).The RCO will determine survey frequencies when the PU submits a project for approval.Types of Radiation Surveys On Contact1 foot (30 cm)1 meter
45 The performance of radiation dose rate surveys is not required in authorized use locations where the radioactive materials are limited exclusively to milliCi quantities of isotopes that emit primarily beta radiation with energies below 250 keV (H-3, C-14, S-35, and P-33). The exclusive use of I-125 immunoassay kits with <25 microCi per kit is also exempted.You must indicate what isotopes you use in the comments section of your monthly RSFUse of P-32, I-125 and all gamma producing isotopes require monthly documented radiation surveys on the RSF
46 Radiation Dose Rate ALARA Action Levels Unrestricted Area normally occupied for 40 hours per week <0.05 mrem/hr @ cm (whole body dose rate)Restricted Area normally occupied for 40 hours per week or unrestricted area with limited occupancy (< 10 hours per week)<2 30 cm (whole body dose rate)Any doserate > 5 mR/hr, notify RSO immediately
47 Survey Records and Reports Keep for 3 Years Explain circled items and that these can be circled as used. All instruments can be added to form and circled as used.
49 Questions ??? 542-5801 www.esd.uga.edu If you have any questions while reading the Radiation Safety ProceduresPlease Feel Free to Contact:The Radiation Safety OfficeEnvironmental Safety DivisionUniversity of Georgia240A Riverbend RoadAthens, GeorgiaKeep checking our website for new stuff