Cathode-Ray Tubes

substance. Monitor the tools and implements for

5. Isolate the immediate area of exposure to

radiation with an authorized radiac set to ensure that

protect other personnel from possible contamination

they are not contaminated.

and exposure.

As you can see, the cleanup that results from

6. Follow the established procedures set forth in

breaking a radioactive tube is a long and complicated

the Radiation, Health, and Protection Manual,

procedure. You can avoid this by simply ensuring that

NAVMED P-5055.

you don't break the tube.

7. Do not permit contaminated material to come

in contact with any part of a person's body.

CATHODE-RAY TUBES

8. Take care to avoid breathing any vapor or dust

Cathode-ray tubes (CRTs) should always be

that may be released by tube breakage.

handled with extreme caution. The glass encloses a

9. Wear rubber or plastic gloves at all times

high vacuum and, because of its large surface area, it

during cleanup and decontamination procedures.

is subject to considerable force caused by atmospheric

pressure. The total force on the surface of a 10-inch

10. Use forceps for the removal of large fragments

CRT may exceed 4,000 pounds, with over 1,000

of a broken radioactive tube. The remaining small

pounds exerted on its face alone.

particles can be removed with a vacuum cleaner, using

an approved disposal collection bag. If a vacuum

The chemical phosphor coating of the CRT

cleaner is not available, use a wet cloth to wipe the

internal face is extremely toxic. When disposing of a

affected area. In this case, be sure to make one stroke at

broken tube, be careful not to come in contact with this

a time. DO NOT use a back-and-forth motion. After

compound. Certain hazardous materials may be

each stroke, fold the cloth in half, always holding one

released if the glass envelope of a CRT is broken. If

clean side and using the other for the new stroke.

contact is made, seek medical aid immediately.

Dispose of the cloth in the manner stated in item 14.

When handling a CRT, you should take the

11. No food or drink should be brought into the

following precautions:

contaminated area or near any radioactive material.

1. Avoid scratching or striking the surface of a

12. Immediately after leaving a contaminated area,

CRT, particularly the rim.

personnel who have handled radioactive material in any

way should remove any clothing found to be

2. Do not use excessive force when removing or

contaminated. They should also thoroughly wash their

replacing a CRT in its deflection yoke or its socket.

hands and arms with soap and water, and rinse them

3. Do not try to remove an electromagnetic type of

with clean water.

CRT from its yoke until the high voltage has been

13. Notify a medical officer immediately if a

discharged from its anode connector (hole).

wound is sustained from a sharp radioactive object. If a

4. Never hold a CRT by its neck.

medical officer cannot reach the scene immediately,

mild bleeding should be stimulated by pressure about

5. Always set a CRT with its face down on a thick

the wound and by the use of suction bulbs. DO NOT

piece of felt, rubber, or smooth cloth.

USE THE MOUTH if the wound is of the puncture type.

If the opening is small, make an incision to promote free

6. Always handle a CRT gently. Rough handling

bleeding and to facilitate cleaning and flushing of the

or a sharp blow on the service bench can displace the

wound.

electrodes within the tube, causing faulty operation.

14. When cleaning a contaminated area, all debris,

7. Safety glasses or goggles and protective gloves

cleaning cloths, and collection bags should be sealed in

should always be worn when you are handling a CRT.

a container, such as a plastic bag, heavy wax paper, or

One additional procedure you should be aware of

glass jar, and placed in a steel can until disposed of

is the proper method of disposal of a CRT. When a

according to existing instructions.

CRT is replaced, the old CRT cannot be simply thrown

15. Decontaminate by use of soap and water all

over the side of the ship or placed in the nearest

dumpster. When thrown over the side of a ship, a CRT

tools and implements used to remove a radioactive

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