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- Mechanische Bewertung (4)
- Numerische Analyse (4)
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- Safety assessment (3)
- Design testing (2)
- Drop test (2)
- Numerical analysis (2)
- Spent fuel transport cask (2)
- Transport packages (2)
- Accident transport conditions (1)
Verification of activity release compliance with regulatory limits within spent fuel transport casks
(2010)
The paper presents technical details of the drop test performance as well as some experimental results of tests carried out with the Japanese 'Yoyushindo-disposal' waste container for intermediate depth disposal. The tests were accompanied by various metrology to collect data as basis for safety assessment.
Fire testing is an essential part of the hypothetical, cumulative mechanical and thermal accident test conditions that shall guarantee package safety in severe accidents. Not only for radioactive material transport packages but also for other containments of dangerous goods international standards require specific thermal load specifications. Following the guideline 'Safety in tech-nology and chemistry' BAM as a scientific and technical German federal government institute operates a 12 km² large open air test facility for experimental investigations of dangerous goods and their containments. On an area besides the well-known 200-ton drop test facility we put into operation new fire test facilities. This facility area provides two fire test stands that are utilized with liquid Propane as fuel from a central earth-covered 60 m³ LPG storage tank. From that stor-age the Propane is pumped via pipelines to the test stands where the gas is released from nozzles, and ignited by ignition burners. The fire exposed test facility areas are 12 m x 8 m. Fire test facil-ity B (with gas release nozzles below water-covered ground) is designed for fire testing of con-tainers that may burst during the test. Fire test facility A (with ring burner systems) is designed for heavy test objects up to 200 tons, e.g. for full-scale spent fuel casks.
The paper will present a detailed description of the facility, insight into first test performances, and results of calorimeter fire tests, using containers of various sizes, to verify the absorbed heat fluxes, demonstrating that regulatory fire test conditions are met, and that the Propane fire can be compared with a kerosene or heating oil pool fire.
Within the last years BAM has carried out numerous drop tests with prototype casks made of ductile cast iron onto targets according to the requirements for final disposal of non-heat generating waste in the German KONRAD repository. The results have shown that the target specifications in the acceptance criteria have to be defined more accurately to get reproducible test results with high precision. Hence, a suitable test stand foundation was developed with much effort. The integrity of the upper concrete layer of this target must be preserved during a test.
Recently the geometrical properties of a tested cubic cast iron container led to a concentration of the impact forces beneath the container walls. The target was damaged strongly with the consequence of inadmissible reduction of cask stresses. For that reason the target construction was modified. However, the basic design was not changed. A prefabricated concrete slab was still joined by a mortar layer to the IAEA target of the BAM drop test facility. In the course of the optimization of the test stand foundation the concrete slab dimensions and the reinforcement were enlarged. During the drop test repetition the target kept intact. Additionally, the mechanical behavior of the cast iron container and the target was analyzed by finite element calculations.
This improved target construction is suggested as a reference target for drop tests with casks whose mass and base area are covered by the container types VI or VII respectively according to the KONRAD repository acceptance criteria.
The measurements during the drop tests with cast iron casks have provided the strains on the cask surface at selected positions. This allows the verification of finite element simulations of drop tests which show the stress distribution also inside the component. In September 2008 a drop test was carried out with a cylindrical cast iron cask containing an artificial material defect which was designed under consideration of critical stress states in the cask body. This drop test could demonstrate the safety against failure by fracture of a cask made of a special cast iron with reduced fracture toughness.
Mechanical design assessment approaches of actual spent fuel and HLW transport package designs
(2010)
Requirements and test programs for sealed radioactive sources are specified in international standards for safety in transport and in use.
Sealed sources which are approved as special form radioactive material according to the Transport Regulations, IAEA Safety Standards TS-R-1, must be able to withstand mechanical (9 m drop, percussion and bending) and thermal (800°C heat) tests without loss of radioactive content.
The International Standard ISO 2919 provides a set of tests which classifies the sources for their safety in use. Performance tests specified in this standard are temperature (high and low), external pressure, impact, vibration and puncture tests. Each test can be applied at different levels of intensity depending on typical usage.
As a criterion of pass or fail, leakage testing has to be done after each test.
The poster gives an overview of BAM s comprehensive test equipment and experience in testing sealed radioactive sources.