Historical review of fire safety at NPP and application of fire PSA to Westinghouse PWR NPP in the frame of risk-informed decision making by

The importance of fire as a potential initiator of multiple-system failures took on a new perspective after the cable-tray fire at Browns Ferry in 1975 The review have shown that the first generation Nuclear Power Plant (NPP) fire safety was not factored as high risk area that needed to be effectively assessed and quantified. This resulted in development of peculiar fire safety regulations, standards and expensive backfits. Lack of appropriate regulations and effective methods of fire risk assessment, prescriptive, difficult and expensive retrofit regulations were instituted in USA. The alternative risk-informed performance based regulation was established in USA to resolve the challenges of the prescriptive rules. The review have revealed that both the prescriptive and risk-informed performance based approaches will not represent adequate design basis for new Nuclear Power Plants. The Japanese were pulled in the path of renew fire safety regulations and risk quantification after the Fukushima accident. It has been recognized that effective fire safety assessment, and culture, in concert with countermeasures to prevent, detect, suppress, and mitigate the effect of fires if they occur, will minimized NPP fire risk. Among the numerous recommendation the fire safety at NPP must be planned and engineered before construction begin using the state-of-the-arts technology. Also, the methods of fire risk assessment must integrate the state-of-the-arts deterministic and probabilistic approaches. Two methods are presented which serve to incorporate the fire-related risk into the current practices in nuclear power plants with respect to the assessment of configurations. The first method is a fire protection systems and key safety functions Unavailability Matrix (UM) which is developed to identify structures, systems, and components significant for fire-related risk. The second method is a fire zones and key safety functions (KSFs) fire risk matrix which is useful to identify fire zones which are candidates for risk management actions. The UM is an innovative tool to communicate fire risk. The Monte Carlo method has been used to assess the uncertainty of the UM. The analysis shows that the uncertainty is sufficiently bounded. The significant fire-related risk is localized in six KSF representative components and one fire protection system which should be included in the maintenance rule. The unavailability of fire protection systems does not significantly affect the risk. The fire risk matrix identifies the fire zones that contribute the most to the fire-related risk. These zones belong to the control building and electric penetrations building. The aggregation of Internal Events PSA model and Fire PSA model have shown that the Fire PSA contributes 38.4% to the Risk increase. The feasibility of developing Fire-related Risk Monitor from the FIRE PSA for the Spanish NPP was carried out. One of the main challenges is that RiskSpectrum® fire PSA has 384 fire cases and 384 CDF but in Risk Monitor one CDF is required. However, CAFTA is unable to convert a Sequential Fault Tree structure of the internal Event tree in the Fire PSA. The conversion fails to implement neither all of the sequences leading to core damage nor the Fault Tree selection of the frequency of fire. The proposal is to suppress exchange events and introduce the alignment of the consequences so that a unique result of core damage can be quantified. The detection and fire suppression Event Trees in the reference model were replaced by detection and fire extinction Fault trees. The frequency of each Fire Case of the conversion model and the reference model are quantified and the frequencies compared. The results shows that 90% of the cases are valid, however, the rest have challenges with MCS. A unique CDF of 7.65x10-7 is quantified compared with 9.83×10-6 of the reference. The conversion of the new model in CAFTA was not successful due to software incompatibility.La importància del incendi com un potencial iniciador de sistema múltiples fallides van agafar una nova perspectiva després del incendi al cable-safata de Browns Ferry el 1975. La revisió ha mostrat que la primera generació de seguretat contra incendis de centrals d'Energia Nuclear (NPP) no va ser àrea de alt risc, àrea que necessitava ser efectivament avaluada i quantificada. Això va resultar en el desenvolupament de normes de seguretat de incendi peculiar, estàndards i cares revisions. La manca d'una reglamentació adequada i mètodes eficaços d'avaluació de risc d'incendi, va fer que als USA foren instituïts mètodes d'adaptació de normativa preceptius, difícils i costós. L'alternativa de regulació informada per el risc es va establir als USA per resoldre els reptes de la regulació preceptiva. La revisió ha mostrat que tant als enfocaments de normativa preceptiva i regulació informada per el risc no representen bases de disseny adequades per a noves NPP. Ha estat reconeguda que la efectiva avaluació de seguretat al incendi i la cultura en concert amb mesures per prevenir, detectar, suprimir i mitigar l'efecte d'incendis, si es produeixen, minimitzarà el risc d'incendi en una NPP. Entre les nombroses recomanacions la seguretat contra incendis a una NPP s'hauran previst i dissenyat abans de començar la construcció i utilitzant estat del art de la tecnologia. També, els mètodes d'avaluació del risc d'incendi tindran que integrar el estat del art en els enfocaments de determinista i probabilístics. Dos mètodes són presentats que serveixen per incorporar el risc relacionats amb el foc a les pràctiques actuals en centrals nuclears en respecte a l'avaluació de configuracions. El primer mètode és un sistema de protecció contra incendis i una matriu de indisponiblitats de les funcions clau de seguretat (MU) que es desenvolupa per a identificar estructures, sistemes i components significatius per riscos relacionats amb els incendis. El segon mètode és zones de focs i matriu de risc d'incendi i funcions (KSFs) clau de seguretat que és útil identificar les zones de foc que són candidats per a les accions de gestió de risc. La MU és una eina innovadora per comunicar el risc d'incendi. El risc significatiu relacionats amb el incendi està localitzat en sis components representatius KSF i un sistema de protecció de foc que cal que figuri en la regla de manteniment. La manca de sistemes de protecció contra incendis no afecta significativament al risc. La matriu de risc d'incendi identifica les zones de foc que mes contribueixen al risc relacionats amb el incendi. Aquestes zones pertanyen a l'edifici de control i edifici de penetracions elèctriques. L'agregació del model de PSA de esdeveniments interns i model de incendis PSA han demostrat que el PSA de incendis aporta 38.4% a l'augment de risc. S'ha desenvolupat la viabilitat del Monitor de risc de incendis a partir del PSA de incendis per a una central nuclear espanyola. Un dels reptes principals és que RiskSpectrum® incendis PSA te 384 casos de incendis i te 384 CDF però en risc Monitor és necessària una CDF. Tanmateix, el CAFTA és incapaç de convertir una estructura seqüencial de arbre de fallida de l'arbre esdeveniment interna en el PSA de incendis. La conversió fracassa al posar en pràctica totes les seqüències de danys al nucli i la selecció de l'arbre de fallida de la freqüència de incendi. La descoberta i supressió de arbres de l'esdeveniment de incendi en el model de referència es van substituir per detecció i els arbres de fallades d'extinció d'incendi. La freqüència de cada cas de incendi del model de conversió i el model de referència son quantificades i les freqüències son comparades. Els resultats demostra que el 90% dels casos són vàlid, no obstant això, la resta té reptes amb MCS. Un únic CDF de 7.65x10-7 s'ha quantificat en comparació amb 9.83 × 10-6 de la referència. La conversió del nou model a CAFTA no va tenir èxit a causa de la incompatibilitat del programari

Food security, risk management and climate change

This report identifies major constraints to the adaptive capacity of food organisations operating in Australia. This report is about food security, climate change and risk management. Australia has enjoyed an unprecedented level of food security for more than half a century, but there are new uncertainties emerging and it would be unrealistic – if not complacent – to assume the same level of food security will persist simply because of recent history. The project collected data from more than 36 case study organisations (both foreign and local) operating in the Australian food-supply chain, and found that for many businesses,  risk management practices require substantial improvement to cope with and exploit the uncertainties that lie ahead. Three risks were identified as major constraints to adaptive capacity of food organisations operating in Australia:  risk management practices; an uncertain regulatory environment – itself a result of gaps in risk management; climate change uncertainty and projections about climate change impacts, also related to risk management

Computer trading and systemic risk: a nuclear perspective

Financial markets have evolved to become complex adaptive systems highly reliant on the communication speeds and processing power afforded by digital systems. Their failure could cause severe disruption to the provision of financial services and possibly the wider economy. In this study we consider whether a perspective from the nuclear industry can provide additional insights

Development of a method for studying cascading effects between critical infrastructures

Most current methods for studying cascading effects rely on written sources to extract information. This thesis presents an empirical method for studying cascading effects, when little written information of the event is available. The method presented has been influenced by incident investigation methods. It has been applied on a case of flooding in south of Sweden and revised based on the results. The case study showed that the method is able to gather and structure information about cascading effects and conditions that affect the outcome of cascading effects. An advantage of this method is that it captures conditions as well as potential cascading effects.Kaskadeffekter inom samhällsviktig verksamhet Det är först när man rullar in trettio minuter försenad på perrongen, som man inser hur kritiska vissa infrastrukturer är för samhället. Ibland beror de här felen på störningar från andra system, så kallade kaskadeffekter. Alla som har växt upp på landet, speciellt innan Gudruns framfart ledde till åtgärder, är plågsamt medvetna om hur jobbigt allting blir när den elektriska energin inte riktigt når fram till sin slutdestination, ditt hem. Ett träd faller över fel ledning och det blir mörkt, vatten kan inte pumpas upp från brunnen, ingen tv, inget internet (för routern är död) och toaletten fungerar bara ett par gånger eftersom det inte kommer vatten. På lite längre sikt: saker i kyl och frys förstörs och hur skall kvällsmaten ordnas? Liknande kaskadeffekter sker även på samhällsnivå. Vid studier av dessa kaskadeffekter använder sig forskare ofta av olycksutredningsrapporter eller artiklar i media för att samla information om händelsen. Ett problem med sådana rapporter och artiklar är att de fokuserar på vad som har inträffat och framförallt varför det inträffade, medan den som studerar kaskad-effekter är intressera av: vad hände sedan? Ibland finns det inte ens någon utredning. För att ändå kunna studera händelser med detta fokus behövs en metodik anpassad för att tackla detta problem, vilket är det arbetet har fokuserat på. Metodiken som togs fram lämpar sig för att samla in information om kaskadeffekter, såsom: vilka system som var inblandade, vilka konsekvenser som uppstod, omfattningen i tid och rum, men även speciella omständigheter, så kallade conditions. Ett exempel på ett condition är effekten av att ett fjärrvärmenät inte kan leverera, på sommaren är det inte så stort problem, men skulle samma händelse inträffa på vintern blir det ganska snabbt problem. En begränsad studie av översvämningarna i Malmö den 31:a augusti 2014 gav visade att ett flertal kaskadeffekter var närvarande, det fanns även gott om conditions som var intressanta. Till exempel klarade sig ett server-rum bra eftersom organisationen bara ett par veckor innan hade installerat två vattenpumpar i rummet. Med mer kunskap om kaskadeffekter, exempelvis genom en databas med studier som den i Malmö, skulle det vara möjligt att se om det finns system som blir särskilt utsatta, eller system som sprider effekter i större utsträckning än andra. Ett annat användningsområde är som inspiration för tänkbara scenarier till risk- och sårbarhetsanalyser på kommunal nivå. Ett tredje område, som dock kräver lite mer omfattande kunskap och utveckling, är integrera databasen i ett beslutfattningsstöd. Då skulle till exempel en insatsledare kunna beskriva typen av händelse och sedan få tillbaka tips på vilka kaskadeffekter som skulle kunna uppstå, därmed har hen en chans att motverka spridningen. Om vi någonsin kommer kunna samla tillräckligt med data och utveckla ett sådant verktyg som är tillräckligt bra för att användas i skarpa lägen, återstå att se

Flood zoning and developing strategies to increase resilience against floods with a crisis management approach

Assessment and planning of crisis management with the approach to natural flood disasters include many factors. In this regard, one of the basic principles of crisis management is based on the resilience of urban infrastructure against floods. This study developed strategies to increase resilience by flood zoning and crisis management. The investigation of the current situation shows that despite the efforts being made, the climatic and environmental conditions of the rivers, the settlements of the infiltration basin, the constructions, and the location inaccuracy of the following structures indicate many challenges in managing the current situation in various components of crisis management. In this regard, the main direction of this article is to evaluate the urban resilience of the Khuzestan region against floods based on a crisis management approach and technique for order preference by similarity to ideal solution (TOPSIS) and Fuzzy weighting methods using geographic information system (GIS)

Investigating the compatibility between Natura 2000 site protection and geomorphological landscapes

Natura 2000 was established under the 1992 Habitats Directive as a EU wide network of nature protection areas by ensuring long-term survival of Europe’s most valuable and threatened species and habitats. Under the Natura 2000 scheme, there are a total of 32 protection areas in both Malta and Gozo. The different structural properties of the various rock layers results in various characteristic formations which are of ecological importance providing important refuge for many Maltese flora and fauna. In Malta, the different geomorphologic features are mainly a result of tectonic movement in which some are still dynamic and over the years will change. As this change occurs, habitats will change and the biota within will be forced to adapt to this change in the abiotic environment. This may result in a change in distribution patterns of species, as competition for niche space may lead to further changes in the overall make-up of the floral assemblage, which will in-turn have an impact on the fauna that depend on the habitat in question. Such modifications within the terrain, may threaten the status of certain species depending on their adaptation and vulnerability to change. The threats on geomorphology are the key factors in compatibility with ecology protection. The examination of the Natura 2000 sites along with the mapping of the geomorphological features shaping these habitats has shown a link between the two. Through this a series of conclusions and a number of recommendations have been drawn out based on these findings

Introduction to Hazards Analysis, in Hazards Analysis: Reducing the Impact of Disasters - Chapter 5

The book details a systematic process of hazards identification, vulnerability determination, and consequence assessment for the natural, built, and human environment. Using a cross-disciplinary approach, this book effectively demonstrates how to use the results of vulnerability assessment, spatial analysis, and community planning to reduce adverse disaster outcomes and foster social, economic, and environmental sustainability. Throughout, the book stresses that hazards analysis is not an isolated process but one that must engage the local community