Light Water Reactor Containment Research Articles

A multi-crucible core-catcher concept: Design considerations and basic results

A pulti-crucible core-catcher concept to be implemented in new light water reactor containments has recently been proposed. This paper deals with conceptual design considerations and the various ways this type of core-catcher could be designed to meet requirements for reactor application. A systematic functional analysis of the multi-crucible core-catcher concept and the results of the preliminary design calculation are presented. Finally, the adequacy of the multi-crucible core-catcher concept for reactor application is discussed.

Leakage potential of LWR containment penetrations under severe accident conditions

This paper is an overview of a Sandia National Laboratories, Albuquerque (SNLA) study of the performance of mechanical penetrations in light-water reactor (LWR) containment buildings that are subjected to severe accident environments. The study is concerned with modes of failure as well as the magnitude of leakage. The following tests have been completed, are under way, or are planned: (a) seals and gaskets have been tested to register the effects of radiation aging, thermal aging, seal geometry, and squeeze on seal and gasket materials in severe accident environments; (b) the performance of a full-scale airlock will be evaluated at severe accident temperature and pressure levels; (c) personnel airlock and equipment hatch tests were made on a 1 8 - scale model of a steel containment building; and (d) tests of mechanical penetrations are planned as part of a test on a 1 6 - scale model of a reinforced concrete building. This program is part of an overall US Nuclear Regulatory Commission (USNRC) effort to evaluate the integrity of LWR containment buildings.

Condensing Heat Transfer Following a Loss-of-Coolant Accident

A new method for calculating the steam mass condensation energy removal rates on cold surfaces in contact with an air-steam mixture has been developed. This method is based on the principles of mass diffusion of steam from an area of high concentration to the condensing surface, which is an area of low steam concentration. This new method of calculating mass condensation has been programmed into the CONTEMPT-LT Mod 26 computer code, which calculates the pressure and temperature transients inside a light water reactor containment following a loss-of-coolant accident. The condensing heat transfer coefficient predicted by the mass diffusion method is compared to existing semi-empirical correlations and to the experimental results of the Carolina Virginia Tube Reactor Containment natural decay test. Closer agreement with test results is shown in the calculation of containment pressure, temperature, and heat sink surface temperature using the mass diffusion condensation method than when using any existing semi-empirical correlation.

Protective Coatings (Paints) for PWR and BWR Reactor Containment Facilities

Protective coatings applied to the interior surfaces of containment facilities are expected to be resistant to an irradiation exposure up to 109 rads, pressures up to 60 psig (followed by a spray of heated borated suppression solution), and to remain in place during and following a design basis accident (DBA) occurring as late as the last day of 40 years of service. Many coating systems exposed to simulated DBA conditions in the laboratory and field evaluations survived the tests. The test data were used as a basis for writing a standard, “ANSI 101.2-1971 Protective Coatings (Paints) for Light Water Reactor Containment Facilities.”