Area Monitors

1. Area Monitors • Neutron and Gamma Area Monitors are Read Out In the Control Room. • Displays Read mRem/Hour. • Red Alarm Lamp Indicates Radiation in Excess of 2.5 mR/Hr. • Only the Control Room Audible Alarm is Connected.

2. Researchers • Researchers Obtain A Thermoluminescent Dosimeter (TLD) On Initial Check In At TUNL. • Researchers Obtain A New Personnel Packet Which Contains the TLD Application and Other Important Documents. • TUNL Provides A Rack In The Control Room For TLD’s. • These Detect X & Gamma Radiation and also Fast Neutrons. • They Must Be Worn At All Times While In The Lab. • They Are Exchanged Every Three Months. • The TLD Reports Are Posted In The Control Room For Inspection.

3. Workers • Workers and Visitors Are Permitted In Research Areas ONLY If No Radiation Is Present. • Workers Obtain A Card Pass From The Secretary In Room 414, Visitors must be escorted by a badged TUNL employee. • TUNL Provides Pocket Dosimeters For Workers or Visitors. • These Detect X & Gamma Radiation from Beam Activated Components or Sources. • They Must Be Signed Out on Entry and Back In On Exit. • The Difference Between The Sign Out and Sign In Readings Must Be Recorded.

4. Visitors • Visitors Are Permitted In Research Areas ONLY If No Radiation Is Present. Visitors must be escorted by authorized TUNL staff. • Minors (under age 18) may accompany adults. • TUNL Provides Pocket Dosimeters For Visitors. • These Detect X & Gamma Radiation from Beam Activated Components or Sources. • They Must Be Signed Out on Entry and Back In On Exit. • The Difference Between The Sign Out and Sign In Readings Must Be Recorded.

5. Kill Switches • Kill Switches Are Located at Each Entrance To The Experimental Areas. • They are located inside of a Red Painted Block on the Walls. • When thrown - down - they interrupt beam from the ion sources at the tandem low-energy Faraday Cup. • The Toggle Switch must be Up in order for the beam to be accelerated. • They may not be over-ridden from any other location.

6. Door Interlocks • Entry Doors and Gates To Experimental Areas are Equipped With Interlock Switches. • When The Door Or Gate Is Opened, The Switch Signals The Safety Circuit. • If The Radiation Level Beyond the Door/Gate is >2.5 mRem/Hr, The Low Energy Faraday Cup Will Be Inserted. • Once Tripped, The Door/Gate Must Be Closed and The Interlock Reset At The Safety Panel. • Interlocks Must NEVER Be Bypassed!

7. Accelerator “ON” Illuminated Signs • Illuminated “Accelerator On” Warning Signs are positioned near entrances to Radiation Areas. • They are illuminated whenever the accelerator control power is on. • These signs alert occupants that the accelerator is in operation and radiation may be present.

8. Klaxon • Loud Klaxon warnings are sounded whenever the accelerator control power is turned on. These last for five seconds. • They warn occupants of the laboratory of the potential for accelerator induced radiation.

9. Audible Warning • State Regulations Require a Fifteen Second Audible Warning before Beam is Introduced Into any Area. • In TUNL, A Laboratory Paging System is in Place at the Console. • Operators must Use the Control Console Mounted Microphone to make a Warning Page before Putting Beam through the Tandem Accelerator. • The Low Energy Faraday Cup Must be Kept In Until The Page is Completed. • This Allows Time for Researchers to Exit or to throw a kill switch.

10. Neutron Monitors • Neutron Monitors are Located In each Experimental Area • They consist of white Polyethylene “Rem Balls” which simulate a human body’s response to neutrons - with BF3 tubes inside • A preamplifier sends the counts from the BF3 tube to the readout in the Control Room. • Area Monitors are tested monthly and calibrated Annually.

11. Gamma-Ray Monitors • Gamma-Ray Monitors are Located In Experimental Areas where either X-Ray Radiation or Gamma-Ray’s may be present from Activated Equipment or Sources. • They consist of small Tan Metal Boxes Mounted on the walls which contain a Geiger Muller Tube. • In Several Locations they are mounted alongside the Neutron Rem Balls. • A preamplifier sends the counts from the GM tube to the readout in the Control Room. • Area Monitors are tested monthly and calibrated Annually.

12. Warning Beacons • Red Rotating Illuminated Warning Beacons are Located in each Experimental Area. • They are activated when the local area monitor detects radiation in excess of 2.5 mRem/Hour. • When a Beacon is active - personnel should not be present in the area. A “Kill” switch can be thrown to interrupt beam. • Doors or gates opened to an area with an illuminated beacon will trip the safety circuit - interrupting beam to the tandem.

13. Safety Circuit • The Safety Circuit Located In The Control Room Monitors The Status of All Area Radiation Monitors, Door Interlocks, and Kill Switches. • The Status Of These Devices Are Indicated On The Safety Circuit Panel Which Contains An Overlay Of The Lab Floor Plan. • When A Door Interlock Is Tripped, The Interlock Must Be Reset On The Safety Circuit Panel After The Area Is Cleared And The Door Closed. • Kill Switches Cannot Be Over-Ridden At The Safety Circuit Panel.

14. High Radiation Areas • High Radiation is Defined as Greater than 100 mRem/Hour. • TUNL has three areas where Neutron Radiation can exceed this level and in fact can approach 10 R/Hr. • These locations are the 20-70 analyzing magnet vault, the Neutron time-of-flight room, and Target Room #1 at the 59-degree scattering chamber. • The door and Gates at the approach to these areas are marked with “Caution High Radiation Area” signs.

15. X-Ray Radiation Areas • X-Rays are produced by high voltage equipment. • TUNL has three areas where X-Ray Radiation may be produced. • These are: the Atomic Beam Polarized Ion Source, The Direct Extraction Negative Ion Source, and the mini-tandem Accelerator. • These areas are posted with “Caution X-Ray Radiation” Signs. • Portable Instruments should be used to survey work areas around these areas when they are in operation.

16. Contaminated Beam Lines • Two Beam Lines In The Tandem Laboratory Have Tritium Contamination. They are Marked With Yellow Warning Signs. • Any Work Requiring Venting These Beam Lines Requires A Work Permit. • Permit Applications Are Available At The Tandem Console. • Applications Will Be Reviewed By the TUNL RSM or Designate. • The Contaminated Beam Lines are the Low-Energy Capture Beam Line and the Neutron Time Of Flight Beam Line.

17. Radiation Areas • All Experimental Areas are Designated Radiation Areas. • The Entry to Each Area is marked with Appropriate Signage. • TUNL Provides Hand-Held Geiger Counters for Personnel Entering These Areas. • These Detect X & Gamma Radiation from Beam Activated Components or Sources. • Some Areas Include Remote Readouts for the Area Monitors in these Areas.

18. Target Areas • All Experimental Areas Where Accelerated Beam May Be Introduced Are Designated Target Areas. • These Include: The Tandem High Energy End, Shielded Source Area, Target Room #1, The NTOF Room, & Target Room #4. • Prior To Introducing Beam Into a Target Area: • A Sweep Must Be Made To Be Sure That No One Is In The Area. • The Area Must Be Secured By Closing All Entries & Exits. • Verify That The Entry Interlock Switch Is Closed At The Safety Panel • Page The Lab To Warn That Beam Is About To Be Introduced To The Specific Area. This Page Must Last A Minimum of 15 Seconds.

19. Survey Meters • All Experimental Areas Have Portable Geiger Counters at their Entrance Door. • These Include: Eberline’s E-120 instrument, and Ludlum Model 2 & 3 Instruments. • Geiger Counters are sensitive mainly to X & Gamma Ray Radiation. • Use Them To Survey for Activated Beamline Components When Entering. • Some probes have a Thin Window That Will Detect Energetic Beta Radiation Also. • Additional Meters Are Kept In a Cabinet In The Control Room. • TUNL has two portable neutron survey meters - called “Snoopy”. They consist of a heavy polyethylene cylinder with a BF3 counter inside. They are insensitive to gamma radiation.

20. Radioactive Waste & Tritium Targets • All Radioactive Contaminated Materials Are To Be Stored In The TUNL Radiological Fume Hood. • Radioactive Waste Should Tagged, Dated and Placed In The Waste Receptacles In This Hood For Disposal By The TUNL RSM. • Tritium Targets Are To Be Stored On The Shelves Provided In The Hood. • The Hood Exhaust is Monitored For Tritium And The High Speed Fan Will Be Activated If The Preset Level Is Exceeded.

21. Radioactive Sources • All Radioactive Sources Must Be Secured Against Unauthorized Access When Not In Use. • Three Locations Are Provided: A Well for Pole Sources, A Locker for Small Check Sources, and Two Safes for Activated Components and Larger Sources. • Keys And Combinations To These Storage Locations Are Available Only To Authorized Personnel. • A Signout Log Is Provided and All Sources Must Be Signed Out And Back In.

22. Radioactive Sources II • A list of Radioactive Sources is posted near the TUNL Source Locker. • Special Handling Instructions are Posted for 241Am sources. • Sources must be signed out and back in on the form provided. • Only Specific Locations are authorized for the use of Radioactive Materials, these are indicated on the “Authorized Locations” form which is posted. • Radioactive Sources may not be transported off campus or on any public road without proper DOT packaging and labeling. Contact the TUNL RSM if you need to use a source off campus.

23. Handling Radioactive Sources • Most TUNL Radioactive Sources are Sealed. • Although Sealed Sources may be handled safely with Bare Hands, it is Prudent to wear Hand Protection. • Check gloves for Activity after Use. Dispose of in ordinary Trash if “clean”. • Alert the RSM or TUNL Director if a source is found to be leaking or is damaged. • If a source is dropped or damaged - contact the RSM to do a leak test immediately.

24. Handling Radioactive Sources II • Especially Strong Sources are mounted on long, 2 meter poles. • The poles allow handling from a distance thereby reducing exposures. • Never tamper with or open the source capsule on the end of the poles. • Alert the RSM or TUNL Director if a pole source is damaged. • If a source is dropped or damaged - contact the RSM to do a leak test immediately. • Store pole sources in the special well behind the source lockers. • Always post a RAM sign near these sources when in use.

25. Handling Radioactive Sources III • TUNL Possesses several Americium-241 Sources that are not sealed. • The Americium is plated onto a metal surface which permits the Alpha particles to be emitted without attenuation. • Never tamper with or touch the Americium Surfaces. • Alert the RSM or TUNL Director if an Americium source is damaged. • If a source is dropped or damaged - contact the RSM to do a leak test immediately. • Americium Sources are stored in a secondary containment and mustbe handled with gloves.