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User`s Manual

1. User s Manual PRM 470A Hand Held Special Nuclear Material Monitor e 1919 86500 8686 E 0 99 SOWVTV 501 LALP 92 79 December 1992 This work was supported by the U 5 Department of Energy Office of Security Affairs Office of Safeguards and Security User s Manual for the PRM 470A Hand Held Special Nuclear Material Monitor Paul E Fehlau r 0338 51 S NATL LAB LIBS LOS ALAMO 3 93380 Table of Contents INTRODUCTION 10 cata o 1 Purpose Of the Manual acia 1 Searching for INM ado di 2 YOUR PRM 470A SEARCH MONITOR E 4 Detecting Radiation 4 Description of the 470 5 CONTROL PANEL FOR THE 470 6 GAMMA RADIATION 11 Radiation Shields 2 2 11 Radiation Sources sssssesssesrsseesssssseosenssessonseseaseessscseseseenes 12 Contamination A 13 Background Radiation A 13 Summary iia 14 OPERATING THE 470 15 Battery R charge viral iia pis treo ENS 15 Turning the Power
2. 16 Setting the Background roer 16 Using the Monitor iaa 17 SEARCH TECHNIQUES FOR PERSONNEL PACKAGES AND 5 556 18 Daily or Shift Change Performance Check 19 Personnel Search cscccsssssssessresssesscssnssserosssseusvosaseeesenseneerees 20 Package 22 Motor Vehicle Search 204 23 Preparing for a motor vehicle search 4 24 44 4 82 23 Searching 22 24 Searching the 24 Searching special vehicles sssssccsserssessserssneseeesseseess 25 What To Do When You Find Radioactive Material 26 Search 0 0 27 INTRODUCTION Purpose of the Manual This manual is for security inspectors who use a PRM 470A hand held SNM monitor to search people packages and vehicles for radioactive material The manual is both a teaching tool and a handy reference It acquaints first time users with the search monitor and the proper techniques for searching It is also a refresher for inspectors who have been reassigned to a search station Finally it serves as a reference at search stations by providing summaries and checklists This manual will acquaint you with the parts of your monitor examine the f
3. that is more frequent beeps However certain shields in the path of gamma rays block their passage just as objects in the Move close with your monitor to find radioactive material 1 Gamma Radiation continued path of light create a shadow Look for shields that may shadow radioactive material and prevent your monitor from detecting it For example brick and concrete walls thick metal containers and sheets of lead are shields that can reduce radiation intensity Radiation Sources The natural surroundings and SNM are not the only sources of gamma radiation Occasionally you may find radioactivity in everyday items For example some people may still wear watches with glow in the dark radium dials that your monitor will sense Radium dial watches are intense radiation emitters and a health hazard to the skin of a person who wears the watch for long periods of time Now most glow in the dark watches have harmless tritium dials that your monitor will not detect because they emit beta radiation which is totally absorbed inside the watch In addition to radioactive watches some camera lenses are radioactive because they are made with a type of glass that may contain thorium a natural radioactive element Another common item that contains thorium perhaps less likely to be encountered at a search station is a Coleman lantern mantle The mantle a small net bag is the part of a gasoline lantern that glows w
4. back Note You may move your monitor rapidly but remember that it will only detect radioactive material if it is close enough to sense it Step 1 Begin your scan near one foot Sweep up one side of the body to the head then sweep down the other side 2 Ask the person to turn around and repeat the inverted U shaped scan Pace your scan Each sweep should take 2 or 3 seconds Hence a front scan will take 5 or 6 seconds turning around takes a few more seconds and a back scan takes 5 or 6 seconds for a total of 15 seconds Scan personnel with a U shaped scan 20 Search Techniques continued Be sure to scan both front and back 21 Search Techniques continued Package Search Briefcases purses and packages are the common items that people carry follow these steps to search them Step 3 Look for large heavy objects that may be radiation shields 3 If a package is sealed and cannot be opened for a visual 5 search use more care in scanning to make sure it does not contain SNM Search slowly over the surface of the package taking plenty of time to scan all sides Exercise care in scanning sealed packages 22 Search Techniques continued Motor Vehicle Search Motor vehicles are more challenging to search for SNM than people or packages The search is a much longer procedure Remember to do a visual search as you scan with your moni
5. will be a slight natural variation caused by changes in the weather Some natural radioactive atoms are part of the atmosphere or are attached to dust that is suspended in the air When it rains these particles are washed out of the air onto the ground and the background radiation level temporarily increases Other more noticeable changes in background may be caused by temporary operations at a work site such as movement of radioactive material or operation of a nuclear reactor In any case your monitor is so sensitive that it will notice even slight variations in background radiation 13 Gamma Radiation continued Summary As we have seen SNM emits radiation that your monitor can detect You should also keep in mind the other sources of radiation that your monitor will detect Neutron sources for example are rarely encountered but neutrons from plutonium are important for detecting plutonium when it is shielded The more common radiation sources that you may encounter on the job are listed below Sources of Radiation Natural background Camera lens containing thorium e Low level contamination Medical radioisotope treatment e Radium dial wristwatch Special nuclear material SNM 14 OPERATING THE PRM 470A Operating your monitor properly takes a certain amount of know how The following steps ensure proper monitoring when you conduct a search and are further described below Step Action 0
6. 2 Make sure the battery is charged and the power is turned on 2 See that the LCD has a steady display of count rates updated each second 3 To conduct a search grasp the instrument firmly in one hand so you can read the writing on the front panel this places the sensitive end of the monitor away from you Note Armed inspectors are expected to keep their strong hand free so the other hand should grasp the PRM 470A Reset the background if necessa 5 Always keep the monitor within 4 to 6 inches of the surface ou are searching Battery Recharge The rechargeable battery will operate the monitor for up to 60 hours When you are not using the monitor for long periods of time recharge it by attaching the charger to it see photograph on following page and plugging the charger into an electrical outlet However don t make the habit of continuously charging the monitor because it is unhealthy for the batteries A second fully charged monitor should be available for use when the first needs to be charged 15 Operating the PRM 470A continued Turning the Power On To operate the monitor
7. from a distance Although it is not so easy to detect small quantities of radioactive material they are just as important to find Your monitor cannot sense a small quantity of radioactive material unless it is nearby This means that you have to scan all surfaces within a few inches and take the time to do a thorough job A copy of this manual should be available at every search station YOUR PRM 470A SEARCH MONITOR Detecting Radiation Detecting radiation is the most effective way to search for hidden quantities of SNM Although searching without a radiation monitor might meet the requirements of the DOE and the NRC that kind of search is slow and may not always locate the nuclear material Because all nuclear material is radioactive and emits radiation searching with a PRM 470A monitor is a better way to find it The PRM 470A is a commercial instrument based on a programmable search monitor developed at the Los Alamos National Laboratory LANL The instrument is an improvement over earlier hand held monitors also developed at LANL and it has found widespread use at nuclear facilities Your PRM 470A Search Monitor continued Description of the PRM 470A Your PRM 470A search monitor has a radiation detector inside it along with electronics that operate the instrument The radiation detector is located just under the display inside the case Each monitor also contains a battery to power the electronics The compact and li
8. g the old background and remember the number 3 when you see a new flashing number the background has been updated and you must 4 press MODE again to return to searching Operating MODE switch cont With this version always check to be sure that you are in search mode when you begin a search Inactive Version V1 01 This version has an inactive MODE switch To update the background you must 1 press POWER to turn off the PRM 470A 2 press POWER to turn it back on and 3 wait for the warmup background measurement countdown and start of operation in search mode Control Panel continued COUNTS SECOND X 1000 Count rate display LIGHT Display light BATTERY CHARGER Battery charge peration The count rate display is an LCD that shows the PRM 470A detector count rate in counts per second To read the count rate multiply the display 0 139 by 1000 to get the result 139 in counts per second If the number on the display changes each second the monitor is searching If the number counts down or flashes on and off the monitor is updating the background If you see LO instead of a number it is because the monitor checks its battery voltage and displays the letters LO sounds its beeper for 5 seconds and turns itself off when the battery is low At night or in dark places you can press LIGHT to illuminate the display LIGHT turns i
9. gh glass whenever possible instead of through metal Take extra time when you are searching the inside of a vehicle from outside Search the cargo areas in trucks and bumpers and the wheel wells in front and behind the tires Search the exterior of the vehicle Include under frame rails 24 Search Techniques continued Include the hood as well in your search Searching special vehicles In addition to the standard scanning procedures for all vehicles some vehicles require additional steps in scanning Follow these additional steps for special vehicles Action Pickup trucks Scan the bed of the pickup Just because the bed is empty does not mean you can skip it A container of SNM may be attached to the underside Large trucks Search wherever possible It helps to have a step vans flatbed small stepladder or step stool to reach the high trucks dump places Search all the accessible spaces and trucks garbage search the exterior of any inaccessible spaces trucks etc Escorted Search even though they have been watched commercial by a security escort The escort is responsible vehicles for watching the occupants which may take their eyes off the vehicle therefore conduct a full search of the vehicle 25 Search Techniques continued What To Do When You Find Radioactive Material Your station orders should tell you specifically what to do when you detect SNM or other radioactive mate
10. ght weight monitor is designed for hand use The case and its contents weigh only 2 9 Ib For its size and weight the monitor is highly sensitive The PRM 470A monitor can sense the low intensity radiation called background radiation that is part of our natural environment The monitor continuously counts pulses produced in its detector by radiation and once each second it displays a new average count rate counts per second on its liquid crystal display LCD Natural background usually produces about 130 counts per second An increase in radiation intensity for example one that is caused by a nearby radiation source will increase the displayed result However don t watch the display to detect SNM watching the display would divert your attention from searching Instead listen for beeps from the monitor to detect SNM To make it possible to detect small increases in count rate the PRM 470A has a small computer that compares its measurements with a recorded background measurement If the computer detects a significant intensity increase it alerts you with a beeping sound The closer you come to the source of radiation the more beeps you will hear until the sound becomes continuous Keep your eyes on the area that you are searching and listen for beeps to discover or locate a source of radiation CONTROL PANEL FOR THE 470 Grasp the PRM 470A firmly with one hand and hold it in front of you so that you can read the writ
11. hen the lantern is lit Only the newest mantles are not radioactive Most of the thorium containing items are low intensity gamma ray emitters you may not be able to detect radiation from an old mantle for instance unless your monitor is almost touching it A relatively uncommon form of radioactivity that security inspectors encounter once in a great while is inside people who are undergoing diagnosis with a medical radioisotope When these individuals present themselves for search before their bodies have had time to eliminate the radioisotope they can be very intense sources of gamma radiation Normally these individuals are cleared through a search station by special procedures 12 Gamma Radiation continued Contamination Another infrequent source of radiation detected at search stations is contamination Occasionally a security inspector will detect a person with contaminated protective clothing or equipment For example an inspector may detect contamination on someone s coveralls This can happen when a persistent gamma ray emitter does not wash out in the laundry Or the contamination may be fresh Security inspectors detect gamma ray contamination because their search monitors are highly sensitive to gamma rays and can detect very small amounts of certain radioactive materials Background radiation Finally a word about the background radiation at a monitoring station The background may vary occasionally Perhaps it
12. ing on the front panel The sensitive front end of the monitor now points away from you as it should during a search Your interface with the PRM 470A is through the front panel The following diagram and tables will familiarize you with its contents Sensitive end COUNTS SECOND X 1000 Z PRM 470A Systems LIGHT BATTERY CHARGER Control Panel continued These tables describe the function of the front panel components Operation Turns the monitor on If you do not see count rates being displayed press the POWER Pressing again turns power off POWER switch The PRM 470A has two operating modes a search mode that detects SNM and a back ground update mode Your PRM 470A will one of three software versions that use the MODE switch in the following different ways Operating Automatic Mode Version V1 02 This version allows you to update the MODE SKIED background automatically Pressing MODE causes the LCD to count from 9 down to 0 as background is measured Then the monitor returns to the search mode You know you have V1 02 if MODE causes a countdown from 9 to 0 Control Panel continued Mode Swap Version V1 00 This version uses MODE to change the PRM 470A operation from one mode to the other So if you are searching and need to update the background you must 1 press MODE to enter background mode 2 watch the display start flashin
13. itional steps Careful search techniques involve the following steps A detailed search checklist can be found at the end of this document 1 Scan the monitor over the surface of every person package and vehicle Avoid contact when monitoring a distance of 2 to 6 inches from a surface is close enough 18 Notice that when the monitor senses a source of radiation it will begin beeping more and more as the monitor approaches the radiation source Pinpoint small sources of radiation by moving the monitor around a radioactive area to find the strongest response Note If the monitor beeps everywhere as you move the monitor around an object the radioactivity may be distributed uniformly over the object This sometimes happens in the case of contamination Search Techniques continued Daily or Shift Change Performance Check Certain checks must be performed regularly to verify that the NNV 470A monitor is operating properly Turn the monitor on if necessar 2 Check that it has a recent background Bring your monitor near the small radioactive source that is kept in the station for performance check and verify that it detects the radiation Verify that your monitor detects radiation 19 Search Techniques continued Personnel Search Follow these procedures to perform a thorough personnel search Allow 15 seconds to conduct it This is enough time to search the person front and
14. press the POWER switch The display will show 8 s and the beeper will sound then the current alarm factor is displayed during a short warm up period Next the display counts down to zero until the monitor is ready for operation and displaying new count rate once per second Setting the Background When the power is turned on the PRM 470A measures the radiation background while it shows a countdown from 9 to 0 on its display The average count rate is not displayed but it is stored in the monitor s memory The alarm factor can be as large as 4 for plutonium monitoring but no greater than 3 for uranium monitoring 16 Operating the PRM 470A continued The background produces count rates of roughly 130 counts per second in the PRM 470A when it is calibrated using the manufacturer s procedures The count rate may be higher or lower at your station A large decrease or increase from count rates that you usually see could indicate that the background has changed for some reason It could also indicate that your monitor may need repair so if it persists tell your supervisor There is one obvious way to tell when you need to take a new background the monitor beeps too often When the background is properly set the monitor may beep occasionally To res t back ground use the procedure for your operating program listed under MODE switch in the section on Panel Functions beginning on p 7 Using the Monitor When the moni
15. rials Use your eyes as well as your ears in searching 26 Search Techniques continued SEARCH CHECKLIST Note Search distance is 2 to 6 inches from surface Preliminaries Monitor is turned on Background is current Personnel Search 15 seconds Front inverted U shaped scan Back inverted U shaped scan Package Search Monitor inside and conduct a visual inspection Monitor outside very carefully for sealed packages Motor Vehicle Search Engine shut off Driver and passengers get out and open compartments e Search occupants e Search engine area under hood Search hood Search trunk area Search trunk lid Search under seats Search dashboard Search sun visor Search headliner Search floor Search behind rear seat Search cargo area of trucks Search under frame rails Search under bumpers Search wheel wells Search bed of pickup trucks 27 Produced by Information Services Division for the Advanced Nuclear Technology Group N 2 Editing Gerry Edwards Composition and Layout Randi Bagley Illustrations AnnMarie Dyson and Rodney L Furan Photographs Daniel F Morse Enrique F Ortega and Robert M Pena This brochure is a revision of a previous publication Hand Held Search Monitor for Special Nuclear Materials User s Manual Los Alamos National Laboratory document LALP 84 15 March 1984 28 _LosAlamos FATIONAL LABORATORY Los Alamos New Mexico 87545
16. tor Check large heavy containers very carefully with your monitor Preparing for a motor vehicle search Certain procedures must be followed before you can even begin to search a motor vehicle Follow these steps to prepare for the motor vehicle search Step Action and has recent background off the engine and open the hood trunk and all doors Request that the driver and any passengers get out of the vehicle and stand away from it during the search Prepare the vehicle for search 23 Search Techniques continued Searching occupants A vehicle search involves not only the vehicle itself but also any occupants of the vehicle Conduct a personnel search of each occupant while they are out of the vehicle Allow them to go back inside after you complete your vehicle search Searching the vehicle You are now ready to conduct a motor vehicle search Follow these steps to ensure a thorough vehicle search Remember to move the monitor within 6 inches of every surface Action Search under the vehicle s hood Don t forget to search the hood itself Search the vehicle s trunk Search the vehicle s interior Enter each door and search around every object and surface within reach Include unlikely places such as the dashboard sun visor headliner area floor under the seats and the space behind the rear seat Note If you cannot reach an area search it from outside the vehicle throu
17. tor is turned on and has a recent background measurement it is ready for use If the monitor is already at the search location you are ready to conduct a search If the monitor is inside the station and you take it outside to search you may have to reset the background Or if it has been quite a while since you set the background you may have to reset it just before starting a search In either case reset the background in the search area but not close to the search object Your best bet is to leave the monitor at the search location to minimize the amount of background resetting Background Radiation A count rate of 130 0 130 or so on the PRM 470A display would be normal in the natural background Radiation Areas Radiation areas where you should not loiter are posted with yellow and magenta warning signs and may have backgrounds of several milliroentgens per hour In these areas the PRM 470A might display numbers in the tens of thousands 10 00 if gamma radiation is the reason for posting 17 SEARCH TECHNIQUES FOR PERSONNEL PACKAGES AND MOTOR VEHICLES Your sensitive and intelligent monitor is only as good as your search technique The care and thoroughness that you take in conducting a search are essential to the security of the access area that you are protecting The recommended search techniques that follow are for locating small quantities of SNM Large amounts are easy to detect of course and require no add
18. tself off after 30 seconds The beeper sound indicates an alarm in search mode Occasional beeps are usually from natural variation in count rate Frequent beeps usually indicate a radiation source The beeper also sounds after POWER is pressed and when the battery is low When the battery is low it can be recharged First turn off the monitor Then attach the charger cable to the monitor and plug the charger into a wall socket Control Panel continued If you see LO displayed hear a long beep or find your PRM 470A turning itself off it needs to be recharged 10 GAMMA RADIATION Gamma radiation is emitted by radioactive atoms that are part of the natural environment Gamma radiation is similar to light except that the eye cannot see it A radiation source emits gamma rays in all directions just as a light bulb emits light in all directions And just as the intensity of light fades rapidly as you move away from a light bulb the intensity of gamma radiation fades as you move away from its source This comparison is true for bare light bulbs only reflectors or lamp shades can redirect visible light but there is no way to redirect the flow of gamma radiation Radiation Shields The closer your monitor comes to radioactive material the greater the radiation intensity and the easier it is to find the material To find radioactive material you should follow the direction of increasing intensity
19. undamentals of radiation explain how to operate the monitor and recommend search techniques Your manual is a handy reference Introduction continued Searching for SNM One of your most important duties as a security inspector is to prevent unlawful removal of special nuclear materials SNM from access areas Plutonium and enriched uranium qualify as SNM The Department of Energy DOE and the Nuclear Regulatory Commission NRC require inspectors to search all persons packages and vehicles for these materials at exits from access areas Introduction continued The search for SNM can be conducted with a hand held monitor that detects radiation emitted by special nuclear materials Although the greatest amount of radiation is gamma radiation plutonium also emits neutrons The PRM 470A monitor has a detector that is particularly sensitive to gamma ray and neutron radiation By using the monitor properly to conduct exit searches you can detect even small quantities of plutonium and enriched uranium When the monitor senses radiation it beeps more and more often as you move it toward radioactive material This makes it possible for you to conduct a search by listening to the beeps You do not have to watch the display You will know you have located the radiation source when the monitor beeps most frequently It is relatively easy to detect a large quantity of radioactive material the monitor senses it

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