Patent Number: 045047391
Section: summary

TECHNICAL FIELD This invention relates to radiation shields of the type comprising a container formed of thin flexible material filled with a radiation attenuating liquid. BACKGROUND OF THE PRIOR ART Radiation shields of the type comprising a container formed of thin flexible material filled with a radiation attenuating liquid were originally disclosed in my U.S. Pat. No. 4,090,087, issued May 16, 1978. Such radiation shields have come into widespread use. However, despite their popularity, their use has presented certain problems, particularly in properly filling and emptying the shields. The radiation shields are stored in a collapsed condition, and, when it is desired to use one, it is taken out and filled with a radiation attenuating liquid, such as a hydrogeneous liquid. If the filling takes place remote from the radiation source, it is sometimes difficult to move the heavy and unwieldy filled shield into place adjacent to the radiation source. And, if the filling takes place adjacent to the radiation shield, the radiation shield sometimes unfolds and extends in unpredictable, exasperating, and potentially dangerous directions and orientations as the attenuating liquid is pumped into the shield, causing the shield to gradually take on its filled shape. When it is desired to empty a radiation shield of this type, the common practice has been to open a liquid drain valve at the bottom and to allow the liquid to drain out. This practice has required lengthy waits, and the drainage is not always complete because there is only atmospheric pressure and/or mechanical manipulations of the bag to force the liquid out. Alternatively, in situations where the radiation shield is connected to a recycling system for the radiation attenuating liquid, such as is disclosed in my U.S. Pat. No. 4,090,087, the pump is either turned off or reversed, but the drainage is still quite slow. OBJECTS OF THE INVENTION It is, therefore, a general object of the invention to provide methods of filling and emptying such radiation shields which will obviate or minimize problems of the type previously described. It is a particular object of the invention to provide a method of filling and forming such radiation shields which permits them to be easily and safely placed in a desired relationship to a radiation shield. It is another object of the invention to provide a method of solidifying such shields in their developed dimensional configurations even when they are not entirely filled with radiation attenuating liquid, either deliberately or due to leakage. It is still another object of the invention to provide a method of emptying such radiation shields which permits them to be rapidly and relatively completely emptied of radiation attenuating liquid. Other objects and advantages of the invention will become apparent from the detailed description of a preferred embodiment thereof given hereinafter. BRIEF SUMMARY OF THE INVENTION The invention comprises (1) a method of filling radiation shields of the type previously described comprising the steps of (a) filling the radiation shield with a gas to form the shield and then (b) replacing the gas with a radiation attenuating liquid, (2) a method of solidifying such shields in their designed dimensional configurations when they are not entirely filled with radiation attenuating liquid, either deliberately or due to leakage, comprising the step of providing an overpressure of gas above the radiation attenuating liquid in the shields, and (3) a method of emptying such radiation shields comprising the step of forcing the radiation attenuating liquid out through one or more outlets by forcing a gas into the radiation shield.