Patent Number: 044951396
Section: description

SPECIFIC DESCRIPTION As seen in the drawing a vessel 1 of spherulitic cast iron has a cover 2 of the same material. The vessel has a mouth formed with a shoulder 23 lying in a plane perpendicular to the vessel center axis, a cylindrical intermediate surface extending up from its outer periphery, and another shoulder 24 parallel to the shoulder 23. Other than these formations, some bolt holes, and a groove 26, the vessel 1 is not machined much, but can be a raw casting. The cover 2 is basically formed of a flange part 4 and a plug part 6. The plug part 6 forms an inner shoulder 5 closely juxtaposed with and axially confronting the shoulder 23, and an intermediate cylindrical surface 7 complementary to the surface 27. The flange forms another shoulder surface 25 confronting and complemtnary to the surface 24. Bolts 21 extending through the outer regions of the flange 4 secure the cover 2 to the vessel 1. A safety cover 21 is secured by further bolts 22 to the rim of the vessel 1 in the groove 26 and serves principally to protect the cover 2 from physical harm. The surfaces 5 and 7 are formed with respective axially downwardly and radially outwardly open grooves receiving respective O-ring seals 10 and 9 that tightly engage the surfaces 23 and 27, and that form an annular compartment 15. The surface 24 of the flange 4 is formed with two concentric and radially spaced grooves that receive respective C-section seals 8a and 8b of an outer seal 8. The rings 8a and 8b together form an annular outer compartment 17, and the ring 8b forms with the ring 9 an intermediate compartment 16. In addition the cover 2 is formed with respective passages 11, 12, and 13 opening into the respective chambers 15, 16, and 17 and provided at their other ends with valves 14 of a monitoring means 3. The cover is formed with an axially upwardly open recess 19 in which the valve 14 of the intermediate chamber 16 opens, although normally it is covered by a cap 28. Another cover 29 closes this recess 19 for maximum protection, and the outer passage 13 of the outer chamber 17 opens directly into this recess 19, so the valve 14 in its cover 29 can be tapped to test for leaks. Normally the interior 18 of the vessel 1 is filled with a pressurized, easily detectable tracer gas above the radioactive material in it. If this gas is detected though the monitoring means 3 in any of the chambers 15-17, the container can be refitted. In any case, the outermost chamber 17 can be sampled easily by removing the safety cover 20, then pulling the cover 30 off the valve 14 in the cover 29 and connecting up to this valve 14. If no leak is detected one can be sure that the cover 29 can be removed to sample the chambers 15 and 16. This is an extremely safe procedure. Thus the container according to the instant invention can be made quite a bit more cheaply than the prior-art one, as all of the tricky machining is done on the relatively portable cover 2. In addition three chambers are provided in a row to test for leakage in the statutorily required failsafe manner, and all three of these chambers are formed by structure on the cover 2. These chambers can be individually sampled and/or charged at superatmospheric pressure.