Publications

Under the sponsorship of the United States Nuclear Regulatory Commission (NRC), Sandia National Laboratories is conducting several research programs with the common goal of developing a complete methodology for the prediction of the ultimate pressure capacity, at elevated temperatures, of light water reactor (LWR) containment systems. These programs are collectively known as the Containment Integrity Programs. This paper will provide a brief overview of these programs. As a part of the Containment Integrity Programs, a series of scale model containment test have been conducted at Sandia including a 1:8-scale steel model and a 1:6 scale reinforced concrete model. The model were pneumatically pressurized up to point of functional failure; that is, the point at which the containment was no longer effective in preventing significant leakage past its pressure boundary. Also, a 1:10-scale prestressed concrete model has been hydrostatically tested in the United Kingdom under a cooperative agreement with the NRC and others. Because the containment pressure boundary consists of numerous mechanical and electrical penetrations, several independent test programs of typical penetrations have also been performed to determine their leakage behavior when subjected to severe accident conditions. Completed containment penetration research programs include testing of typical compression seals and gaskets, inflatable seals, a personal air lock and electrical penetration assemblies (EPAs). Also, an investigation of leakage due to ovalization of penetration sleeves has been conducted as a part of the scale model test. Currently, testing of the unseating equipment hatch of the 1:6-scale containment model is under way. 23 refs., 3 figs., 2 tabs.

Sandia National Laboratories, under the sponsorship of the United States Nuclear Regulatory Commission, is currently developing test validated methods to predict the pressure capacity of light water reactor containment buildings when subjected to postulated severe accident conditions. These conditions are well beyond the design basis. Scale model tests of steel and reinforced concrete containments have been conducted as well as tests of typical containment penetrations. As a part of this effort, a series of tests was recently conducted to determine the leakage behavior of inflatable seals. These seals are used to prevent leakage around personnel and escape lock doors of some containments. The results of the inflatable seals tests are the subject of this report. Inflatable seals were tested at both room temperature and at elevated temperatures representative of postulated severe accident conditions. Both aged (radiation and thermal) and unaged seals were included in the test program. The internal seal pressure at the beginning of each test was varied to cover the range of seal pressures actually used in containments. For each seal pressure level, the external (containment) pressure was increased until significant leakage past the seals was observed. Parameters that were monitored and recorded during the tests were the internal seal pressure, chamber pressure, leakage past the seals, and temperature of the test chamber and fixture to which the seals were attached. 8 refs., 34 figs., 7 tabs.