Underneath the reactor containment vessel can be seen some of the shape of the vessel and the supporting foundation that distributes its weight to the hull. The vessel is attached to the ship's structure only at the aft end with 24-2 1/4" high-strength bolts. This allows the vessel to expand and contract as its temperature changes. The supports all round insure that the vessel would not be dislocated even in a 90° heel of the ship.
Each of the five openings and 76 penetrations was tested to the same 173 PSIG resulting from the maximum credible accident as the pressure hull itself.
One of the two special manholes at the bottom of the vessel is shown. It is designed so that should the ship sink, at about 100 foot deep its securing bolts will shear and allow the containment vessel to fill with water preventing its collapse in deep water. Once the pressure inside and out are the same, a spring closes the cover to prevent the escape of contained material.
Also in this area are several storage tanks for contaminated water that might have leaked out of valves, etc. It was stored here until safe disposal was available.
Just outside of view is the area where the primary loop purification equipment was located. Water to and from the charging and let down system was filtered here. The purity of the primary cooling water was essential to the safe and efficient operation of the reactor. The purification ion exchangers and gaseous absorption units where removed during the early steps in decommissioning Savannah.