Session: OAC-04-01 Storage and Transportation of Radioactive and other Hazardous Materials

Paper Number: 154619

154619 - A Fire Test Stand for Thermal Testing of Extra-Large Packages 

Abstract: 

Packages for the transport of high-active radioactive materials are designed to withstand severe accidents. These packages must adhere to the specification-based criteria of the International Transport Regulations of the International Atomic Energy Agency (IAEA). To ensure compliance with these requirements, specific mechanical and thermal tests need to be addressed with respect to the package type. Typically, the Regulations prescribe mechanical tests followed by a thermal test as part of a cumulative test scenario. The thermal test is specified by the exposure of a test specimen for a period of 30 Minutes to a thermal environment that provides a heat flux equivalent to that of a hydrocarbon fuel-air fire with an average fire temperature of at least 800°C and fully engulfing the test specimen. The Federal Institute for Materials Research and Testing (BAM) operates various test facilities for this purpose at their test site near Berlin in Germany, to verify the compliance of packages for the transport of radioactive material with the regulatory requirements.

The thermal tests are carried out in an established fire test stand that can be adapted by the test-setup to the geometric boundary conditions of a test specimen. The fire test stand is mainly built of a flat concrete trough in the dimensions of 12 m x 8 m for test specimens with masses up to 200,000 kg and geometric dimensions relating to large transport packages including their impact limiters. The test specimen is usually placed on a water-cooled rig in the middle of the concrete trough. The fire is realized by burning propane gas which is released horizontally in liquid state from an array of gas nozzles in a pipe surrounding the test specimen in form of a ring burner. A permanent water circulation system cools the propane gas pipes and the concrete trough. For particularly extra-large test specimens, two burner rings are used, one above the other and at different heights to achieve first, full fire engulfment with a significantly larger volume of fire and secondly, the required heat output. The heat output can be mainly regulated by variating the mass flux of the propane, the number of nozzles and its cross-section. The effect of side wind is regulated using wind deflector plates made of heat-resistant steel sheets surrounding the concrete trough.

Usually, BAM performs so-called fire reference tests or calorimeter tests in advance of a regular fire test to determine the test conditions for compliance with the IAEA requirements. These tests are carried out using a generic package, the fire reference package, which corresponds to the external geometric dimensions of the test specimen used later in the approval test. The reference package, which is fully instrumented with thermocouples on the inside of the container walls, is then exposed to a fire for several minutes in the fire test stand under defined test parameters. Then, the heat input to the package is determined from the temperature changes measured on the package.

The paper shows the experimental proof of the suitability of the fire test stand for thermal testing of extra-large packages based on fire reference tests performed with a test specimen built of a large cylindrical cask body and cylindrical impact limiters. The heat input and fire temperatures fully meet the IAEA criteria but can also be set significantly higher for e.g. extra-regulatory testing.

Presenting Author: Thomas Quercetti Bundesanstalt fuer Materialforschung und -prüfung (BAM)

Presenting Author Biography: Currently responsible for the working group ‘Experimental Testing of Containers’ within the division ‘Safety of Transport Containers’ at the Federal Institute for Materials Research and Testing (BAM), Germany. Research and project engineer on the field of safety of transport casks for radioactive materials.

Authors:

Thomas Quercetti Bundesanstalt fuer Materialforschung und -prüfung (BAM)
Martin Feldkamp Bundesanstalt für Materialforschung und -prüfung (BAM)
Tobias Gleim Bundesanstalt für Materialforschung und -prüfung (BAM)
Andre Musolff Bundesanstalt für Materialforschung und -prüfung (BAM)
Jan Werner Bundesanstalt für Materialforschung und -prüfung (BAM)
Frank Wille Bundesanstalt für Materialforschung und -prüfung (BAM)