TY - JOUR A1 - Sipilä, J. A1 - Auerkari, Pertti A1 - Heikkilä, A.-M. A1 - Tuominen, R. A1 - Vela-Wallenschus, Iris A1 - Itkonen, J. A1 - Rinne, M. A1 - Aaltonen, K. T1 - Risk and mitigation of self-heating and spontaneous combustion in underground coal storage N2 - While the self-heating and spontaneous combustion of coal is a known challenge at coal mines and storage sites, there are known methods for mitigating this challenge for typical open stockpile storage. However, closing the storage will reduce access for corrective action, and it is then important to manage the storage and its transport system with added attention without unduly adding cost or hindering availability. This paper aims to discuss the risk, prevention and extinguishing of fires in closed coal storage facilities, particularly in light of the experience with the Salmisaari underground rock storage facility in Finland. The observed autoignition events have indicated an array of contributing factors, some of which are unique to underground silo storage facilities. On the other hand, many features of the storage facilities can be compared with other extant closed storage systems. The factors affecting fire risk are described and the associated fault and event trees are outlined for autoignition at underground storage. Drawing upon the experiences with past events of self-heating and spontaneous combustion, recommendations are given on cost-effective preventive, corrective and other mitigating action for minimising fire risk and promoting storage availability. KW - Coal KW - Underground storage KW - Fire KW - Risk KW - Mitigation PY - 2012 U6 - https://doi.org/10.1016/j.jlp.2012.01.006 SN - 0950-4230 SN - 1873-3352 N1 - Geburtsname von Vela-Wallenschus, Iris: Vela, I. - Birth name of Vela-Wallenschus, Iris: Vela, I. VL - 25 IS - 3 SP - 617 EP - 622 PB - Butterworth CY - Guildford, Surrey AN - OPUS4-25729 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sipilä, J. A1 - Auerkari, Pertti A1 - Malmén, Y. A1 - Heikkilä, A.-M. A1 - Vela-Wallenschus, Iris A1 - Krause, U. T1 - Experience and the unexpected:risk and mitigation issues for operating underground storage silos for coal-fired power plant N2 - Observed autoignition events and extinguishing the resulting smouldering fires in an underground storage system of a coal-fired power plant have provided insight into the array of contributing variables, and some experience on quantifying the risk with alternative scenarios of event initiation, progress and potential mitigation. Although the first attempts to quantify the risk suggest high sensitivity to the sequence of action taken after fire alarm, and no similar storage sites really exist, some recommended preventive, corrective and other mitigating activities can be at least partly defined and improved by using the cumulative experience and parallel efforts in other closed or underground storage sites. However, there are also so-called black (or at least grey) swans: unexpected events for which the facility may be poorly prepared for. In the case of the underground storage silos, such an event was experienced when incoming cold coal during a harsh winter season froze the sewer system that normally protects the stored coal from seepage water. With blocked normal bypass, the seepage water found its way to the coal silos and created large clumps of icy coal that blocked the coal conveyors. Although freezing weather is not unusual at high-latitude power plants, the common methods to combat freezing of coal are mainly useful for open storage sites and above-ground transport. Options for mitigation are discussed, as well as the event chain leading to an event that had never previously occurred. The case is discussed from the point of view of options to prepare for rare or unforeseen events. KW - Coal KW - Underground storage KW - Fire KW - Freezing KW - Risk KW - Mitigation PY - 2013 U6 - https://doi.org/10.1080/13669877.2012.729530 SN - 1366-9877 SN - 1466-4461 N1 - Geburtsname von Vela-Wallenschus, Iris: Vela, I. - Birth name of Vela-Wallenschus, Iris: Vela, I. SP - 1 EP - 14 PB - Taylor & Francis CY - London [u.a.] AN - OPUS4-28260 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lerena, P. A1 - Auerkari, Pertti A1 - Knaust, Christian A1 - Vela-Wallenschus, Iris A1 - Krause, U. T1 - Approaches towards a generic methodology for storage of hazardous energy carriers and waste products N2 - Energy carriers – either conventional or 'new' ones – have to be provided in large amounts to meet the requirements of permanent availability and reliable supply of electricity. Depending on their state of aggregation, energy carriers are either stored in large masses (if solid or liquid) or at elevated pressures (if gaseous). Both impose the hazard of large-scale fire, in the latter case additionally the danger of explosion or unintended release. Very similar hazards occur for wastes. Solid wastes are present in large masses and only a small part is recycled. Most of the solid wastes are used in energy conversion. The main gaseous waste is CO2. During capturing also the hazard of unintended release exists. In this article, existing approaches for safe storage and fire prevention are discussed and a generic methodology is outlined. This methodology consists of the following steps: • gaining knowledge about the behaviour of the material stored (reactivity, thermal stability, etc.), • assessing the environmental conditions for the storage site (neighbourhood, safety distances, etc.), • assessment of prospective consequences of an incident and • development of individual loss prevention conceptions. All steps require both experimental testing and theoretical considerations about accident scenarios as integral parts of the methodology. KW - Storage KW - Hazardous materials KW - Energy carriers PY - 2013 U6 - https://doi.org/10.1080/13669877.2012.729524 SN - 1366-9877 SN - 1466-4461 N1 - Geburtsname von Vela-Wallenschus, Iris: Vela, I. - Birth name of Vela-Wallenschus, Iris: Vela, I. VL - 16 IS - 3-4 SP - 433 EP - 445 PB - Taylor & Francis CY - London [u.a.] AN - OPUS4-26882 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sipilä, J. A1 - Auerkari, Pertti A1 - Holmström, S. A1 - Vela-Wallenschus, Iris T1 - Early warning indicators for challenges in underground coal storage N2 - Early warning or leading indicators are discussed for unexpected incidences in case of large-scale underground coal storage at a power plant. The experience is compared with above-ground stockpiles for which established procedures are available but where access for prevention and mitigation are much easier. It is suggested that while the explicit organization, procedures, and the general safety systems aim to provide the targeted levels of performance for the storage, representing new technology without much precedence elsewhere in the world, the extensive experience and tacit knowledge from above-ground open and closed storage systems can help to prepare for and to prevent unwanted incidents in the underground storage. This kind of experience has been also found useful for developing the leading or early warning indicators for underground storage. Examples are given on observed autoignition and freezing of coal in the storage silos, and on occupational hazards. Selection of the leading indicators needs to consider the specific features of the unique underground facility. KW - Fire KW - Freezing KW - Risk indicator KW - Safety KW - Underground storage PY - 2014 U6 - https://doi.org/10.1111/risa.12273 SN - 0272-4332 SN - 1539-6924 N1 - Geburtsname von Vela-Wallenschus, Iris: Vela, I. - Birth name of Vela-Wallenschus, Iris: Vela, I. VL - 34 IS - 12 SP - 2089 EP - 2097 PB - Blackwell Publ. CY - Malden, Mass. [u.a.] AN - OPUS4-32511 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -