Safety and Accident Analysis Services

RMA offers a full range of services related to the use of the MELCOR, MAAP, RELAP and SCDAP computer codes, which are developed by the US Nuclear Regulatory Commission. RELAP is a first principle thermal hydraulic nodalization code for transient and design basis safety analyses of PWRs or BWRs. Best estimate assumptions or licensing assumptions can be used. SCDAP and MELCOR are first principle nodalization codes for severe accident progression analyses. The progression of core damage accidents can be analyzed from the initiating event to the release of an accident source term from the containment. These codes continue to be improved under an international cooperation agreement, under which they are available for use by US and non-US users. RMA’s range of services includes:

  • Develop plant specific models for transient and accident analyses.
  • Develop models for safety systems, control systems and plant protection systems.
  • Perform client requested analyses using these codes and models.
  • Activate MELCOR, MAAP and RELAP models for interactive accident analysis using the MEL_SIMTM, MAAP_SIMTM or REL_SIMTMsystem respectively.

One of RMA’s areas of specialization is the development of validated RELAP plant models for operational transient, safety and licensing analyses that power plants and their utilities can use in-house for training and as an alternative to contracting such analyses to the plant manufacturer. These RELAP models include models for the power conversion system (turbine and condenser) and for the containment. They are developed from data available at the power plant without the use of proprietary data from the plant manufacturer. A plant specific RELAP model is tested against recorded plant transient data and other available information.