Safety Aspects

 

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There are a few safety aspects in relation to the Kr81m generator.

Weight

Probably the greatest risk is the weight of the generator system! The lead shielding means that the generator can weigh about 13kg or more. Standard lifting precautions must therefore be taken when setting up and moving the generator. A movable trolley can avoid too much manual handling.

External Radiation Dose

The generator gives an external exposure due to the high energy gamma emissions of the Rubidium radionuclides. This will depend on the activity of the generator and also on the production technique. General radiation precautions of using distance and time to reduce any exposure should be used. Although a secondary shield is designed primarily to reduce the camera background it clearly cuts down operator exposure also. Typical values for external dose rate are given below for a generator without the secondary shield, reflecting the situation during delivery and unpacking.

Typical external dose rates from a 600MBq generator   -    ÁSv.hr-1
(no secondary shield in place)
External Surface of generator xx
20cm from generator (approx. at  surface of transport container) xx
1m from generator xx

NB

Never dismantle the generator. The dose rate on the surface of the column can be xxxxxxxx ÁSv.hr-1

Contaminants

There is always a potential for radioactive contaminants of the Kr81m from the Rubidium radionuclides on the generator. This is obviously a very unlikely event although very small levels of contaminant can get through the generator filters. These do not pose a radiation risk to the patient. However an in-line micropore filter can act as a barrier. The only precaution with this is that if the filter gets wetted, even from   a few drops of moisture, then its resistance to flow can stop the generator.

Return of Spent Generator

Remember that a 'spent' generator can still be radioactive even after a few days. There may be some Rb83 and Rb84 present on the generator. The packaging for return of the generator may therefore need to reflect this.

 

 

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Last modified: November 29, 2002