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This slide presentation reviews risk assessment and its role in risk-informed decision making. It includes information on probabilistic risk assessment, typical risk management process, origins of risk matrix, performance measures, performance objectives and Bayes theorem.
The Johnson Space Center has pursued integrating risk management practices and techniques throughout a large organization with an extraordinarily diverse mission. Past mission and institutional failures have been used to inform NASA's safety culture and a implement a uniform risk management environment. Basics from the loss prevention industry have influenced NASA's approach to sustaining its unique, yet aging, infrastructure. Lessons learned at NASA can augment and enhance occupational safety, health and risk management capabilities within hazardous industries. By focusing on risk informed decision-making, building a pervasive safety culture, and accommodating human factors, NASA's safety capabilities have been specifically developed to minimize the risk of loss of life and loss of mission.
Aerospace electrical systems are required to withstand and adequately operate in extremely harsh environments that include, for example, high radiation exposure, temperature extremes, intense vibrational stress and drastic temperature cycling. The nature of aerospace electronics also demands high reliability since, with very few exceptions, there is no chance for hardware servicing or repairs. Common risk mitigation techniques for this type of situation are to perform a Reliability Analysis of the system throughout the development cycle, and to use electrical components that are regarded as “high reliability” because of additional controls and requirements applied in their design, manufacturing and testing. Unfortunately, studies have shown that even though these techniques are used, many systems fail to meet mission requirements well before the predicted lifetimes. This paper presents the analysis of failures of electrical parts, experienced during various stages of system development, at NASA Goddard Space Flight Center, Greenbelt MD, between the years 2001 and 2013. These components were subjected to qualification, screening and testing in which the goal was to ensure that the components would survive the stresses of the mission. The analysis categorizes failures by part type and failure mechanisms. One of the results of the analysis was the realization that a surprising proportion of failures experienced during system integration and testing were caused by human error (i.e. human induced defect). Further analysis included the determination of root failure mechanisms and any influencing factors contributing to these failures. The major causes of these defects were attributed to electrostatic damage (ESD), electrical overstress (EOS), mechanical overstress (MOS), and thermal overstress (TOS). Finally, the study proposes a risk analysis tool which incorporates these major causes for the failures, termed error-producing conditions (EPCs), and a proportionality factor representing the number of each type of failure that has occurred at the facility under study. These factors are quantified and used to communicate the risk of human induced defects for the assembly, integration and testing of space hardware based on the system’s electrical parts list. The new risk identification can trigger risk-mitigating actions more effectively, based on the presence of component categories or other hazardous conditions that have a history of failure due to human error.
NASA's Risk Management Program is designed to communicate risk at all levels of the Agency. This presentation serves as an introduction to NASA Risk Management principles and risk-informed decision making. The contents of this presentation are intended to familiarize attendees of NASA's Quality Leadership Forum with how to incorporate risk communication into their practices.
Exposure to space radiation and other spaceflight hazards may pose an increased risk for cardiovascular diseases (CVD) during and after spaceflight [1], that should be quantified to plan future long-duration space missions such as the flight to Mars. The first CVD clinical prediction models (CPMs) for individuals were developed by the Framingham Heart Study investigators in the 1960’s. Since then, many CPMs have been developed and refined. The CPMs consider cardiovascular risk factors such as blood pressure, diabetes, cholesterol, and smoking. As there is a relationship between radiation-induced CVD risk and the background (non-exposed) CVD risk, it is possible to use CPMs to calculate a personalized risk for astronauts.
Guidance on Sensor Placement was identified as the top research priority for hydrogen sensors at the 2018 HySafe Research Priority Workshop on hydrogen safety in the category Mitigation, Sensors, Hazard Prevention, and Risk Reduction. This paper discusses the initial steps (Phase 1) to develop such guidance for mechanically ventilated enclosures. This work was initiated as an international collaborative effort to respond to emerging market needs related to the design and deployment equipment for hydrogen infrastructure that is often installed in individual equipment cabinets or ventilated enclosures. The ultimate objective of this effort is to develop guidance for an optimal sensor placement such that, when integrated into a facility design and operation, will allow earlier detection at lower levels of incipient leaks, leading to significant hazard reduction. Reliable and consistent early warning of hydrogen leaks will allow for the risk mitigation by reducing or even eliminating the probability of escalation of small leaks into large and uncontrolled events. To address this issue, a study of a real-world mechanically ventilated enclosure containing GH2 equipment was conducted, where CFD modeling of the hydrogen dispersion (performed by AVT and UQTR, and independently by the JRC) was validated by the NREL Sensor laboratory using a Hydrogen Wide Area Monitor (HyWAM) consisting of a 10-point gas and temperature measurement analyzer. In the release test, helium was used as a hydrogen surrogate. Expansion of indoor releases to other larger facilities (including parking structures, vehicle maintenance facilities and potentially tunnels) and incorporation into QRA tools, such as HyRAM is planned for Phase 2. It is anticipated that results of this work will be used to inform national and international standards such as NFPA 2 Hydrogen Technologies Code, Canadian Hydrogen Installation Code (CHIC) and relevant ISO/TC 197 and CEN documents.
Directive 2002/32/EC of 7 May 2002 of the European Parliament and of the Council on undesirable substances in animal feed is the framework for the EU action on undesirable substances in feed. This framework Directive provides: ⁎that products intended for animal feed may enter for use in the Union from third countries, be put into circulation and/or used in the Union only if they are sound, genuine and of merchantable quality and therefore when correctly used do not represent any danger to human health, animal health or to the environment or could adversely affect livestock production. ⁎that in order to protect animal and public health and the environment, maximum levels for specific undesirable substances shall be established where necessary. ⁎for mandatory consultation of a scientific body (EFSA) for all provisions which may have an effect upon public health or animal health or on the environment. ⁎that products intended for animal feed containing levels of an undesirable substance that exceed the established maximum level may not be mixed for dilution purposes with the same, or other, products intended for animal feed and may not be used for the production of compound feed. Based on the provisions and principles laid down in this framework Directive, maximum levels for a whole range of undesirable substances have been established at EU level. During the discussions in view of the adoption of Directive 2002/32/EC, the European Commission made the commitment to review all existing provisions on undesirable substances on the basis of updated scientific risk assessments. Following requests of the European Commission, the Panel on Contaminants in the Food Chain (CONTAM) from the European Food Safety Authority (EFSA) has completed a series of 30 risk assessments undertaken over the last 5 years on undesirable substances in animal feed reviewing the possible risks for animal and human health due to the presence of these substances in animal feed. EU legislation on undesirable substances has undergone recently several changes to take account of these most recent scientific opinions. Furthermore EFSA has assessed the risks for public and animal health following the unavoidable carry-over of coccidiostats into non target feed. Maximum levels for the unavoidable carry-over have been established for the non-target feed and the food of animal origin from non-target animal species.
A risk-based decision-making methodology conceived and developed at JPL and NASA has been used to aid in decision making for spacecraft technology assessment, adoption, development and operation. It takes a risk-centric perspective, through which risks are used as a reasoning step to interpose between mission objectives and risk mitigation measures.
Purpose: The aim of this study was to evaluate the impact of variations in pelvic dimensions on the dose delivered to the target volumes and the organs at risk (OARs) in patients with high-risk prostate cancer (PCa) to be treated with whole pelvic radiation therapy (WPRT) in an attempt to define the hostile pelvis in terms of intensity modulated radiation therapy (IMRT). Methods and Materials: In 45 men with high-risk PCa to be treated with WPRT, the target volumes and the OARs were delineated, the dose constraints for the OARs were defined, and treatment plans were generated according to the Radiation Therapy Oncology Group 0924 protocol. Six dimensions to reflect the depth, width, and height of the bony pelvis were measured, and 2 indexes were calculated from the planning computed tomographic scans. The minimum dose (D{sub min}), maximum dose (D{sub max}), and mean dose (D{sub mean}) for the target volumes and OARs and the partial volumes of each of these structures receiving a specified dose (V{sub D}) were calculated from the dose-volume histograms (DVHs). The data from the DVHs were correlated with the pelvic dimensions and indexes. Results: According to an overall hostility score (OHS) calculation, 25 patients were grouped as having a hospitable pelvis and 20 as having a hostile pelvis. Regarding the OHS grouping, the DVHs for the bladder, bowel bag, left femoral head, and right femoral head differed in favor of the hospitable pelvis group, and the DVHs for the rectum differed for a range of lower doses in favor of the hospitable pelvis group. Conclusions: Pelvimetry might be used as a guide to define the challenging anatomy or the hostile pelvis in terms of treatment planning for IMRT in patients with high-risk PCa to be treated with WPRT.
Using CO2 in enhanced oil recovery (CO2-EOR) is a promising technology for emissions management because CO2-EOR can dramatically reduce sequestration costs in the absence of emissions policies that include incentives for carbon capture and storage. This study develops a multiscale statistical framework to perform CO2 accounting and risk analysis in an EOR environment at the Farnsworth Unit (FWU), Texas. A set of geostatistical- based Monte Carlo simulations of CO2-oil/gas-water flow and transport in the Morrow formation are conducted for global sensitivity and statistical analysis of the major risk metrics: CO2/water injection/production rates, cumulative net CO2 storage, cumulative oil/gas productions, and CO2 breakthrough time. The median and confidence intervals are estimated for quantifying uncertainty ranges of the risk metrics. A response-surface-based economic model has been derived to calculate the CO2-EOR profitability for the FWU site with a current oil price, which suggests that approximately 31% of the 1000 realizations can be profitable. If government carbon-tax credits are available, or the oil price goes up or CO2 capture and operating expenses reduce, more realizations would be profitable. The results from this study provide valuable insights for understanding CO2 storage potential and the corresponding environmental and economic risks of commercial-scale CO2- sequestration in depleted reservoirs.
If Carbon dioxide Capture and Storage (CCS) is to be effective in mitigating climate change, it will need to be carried out on a very large scale. This will involve many thousands of miles of dedicated high-pressure pipelines in order to transport many millions of tonnes of CO 2 annually, with the CO 2 delivered to many thousands of wells that will inject the CO 2 underground. The new CCS infrastructure could rival in size the current U.S. upstream natural gas pipeline and well infrastructure. This new infrastructure entails hazards for life, health, animals, the environment, and natural resources. Pipelines are known to rupture due to corrosion, from external forces such as impacts by vehicles or digging equipment, by defects in construction, or from the failure of valves and seals. Similarly, wells are vulnerable to catastrophic failure due to corrosion, cement degradation, or operational mistakes. While most accidents involving pipelines and wells will be minor, there is the inevitable possibility of accidents with very high consequences, especially to public health. The most important consequence of concern is CO 2 release to the environment in concentrations sufficient to cause death by asphyxiation to nearby populations. Such accidents are thought to be very unlikely, but of course they cannot be excluded, even if major engineering effort is devoted (as it will be) to keeping their probability low and their consequences minimized. This project has developed a methodology for analyzing the risks of these rare but high-consequence accidents, using a step-by-step probabilistic methodology. A key difference between risks for pipelines and wells is that the former are spatially distributed along the pipe whereas the latter are confined to the vicinity of the well. Otherwise, the methodology we develop for risk assessment of pipeline and well failures is similar and provides an analysis both of the annual probabilities of accident sequences of concern and of their consequences, and crucially the methodology provides insights into what measures might be taken to mitigate those accident sequences identified as of concern. Mitigating strategies could address reducing the likelihood of an accident sequence of concern, or reducing the consequences, or some combination. The methodology elucidates both local and integrated risks along the pipeline or at the well providing information useful to decision makers at various levels including local (e.g., property owners and town councils), regional (e.g., county and state representatives), and national levels (federal regulators and corporate proponents).
The risk associated with the accidental release of carbon/graphite fibers (CF) from fires on commercial transport aircraft incorporating composite materials was assessed. Data are developed to evaluate the potential for CF damage to electrical and electronic equipment, assess the cost risk, and evaluate the hazard to continued operation. The subjects covered include identification of susceptible equipments, determination of infiltration transfer functions, analysis of airport operations, calculation of probabilities of equipment failures, assessment of the cost risk, and evaluation of the hazard to continued operation. The results show the risks associated with CF contamination are negligible through 1993.
NASA uses environment models such as ORDEM96 to characterize the long-term orbital debris collision hazard for spacecraft in LEO. Occasionally, however, there are breakups of satellites or rocket bodies that create enhanced collision hazard for a period of time. This enhanced collision hazard can pose increased risks to space operations - especially those involving manned missions where the tolerance for risk is very low. NASA has developed SBRAM to simulate the enhanced debris environment in the days and weeks that follow such a breakup. This simulation provides the kind of risk probabilities that can be used by mission planners to consider if changes are warranted for the mission. Announcements of breakups come to NASA from US Space Command as soon as they are identified. The pre-breakup orbit and time of breakup are used to determine the initial conditions of the explosion. SBRAM uses the latest explosion models developed at NASA to simulate a debris cloud for the breakup. The model uses a Monte Carlo technique to create a random debris cloud from the probability distributions in the breakup model. Each piece of debris randomly created in the cloud is propagated in a deterministic manner to include the effects of drag and other orbital perturbations. The detailed geometry of each simulated close approach to the target spacecraft is noted and logged and the collision probability is computed using an estimated probability density in down-range and cross-range positions of both the target spacecraft and debris object. The collision probability is computed from the overlap of these probability densities for each close-approach geometry and summed over all computed conjunctions. Cloud propagation runs over the desired time interval are then repeated until the scale of the collision risk can be estimated to a desired precision. This paper presents an overview of the SBRAM model and a number of examples, both real and hypothetical, to demonstrate its use. In addition, a number of different examples are shown how the data can be used by decision makers on issues such as spacecraft orientation and timing of EVAs.
The Mini-Research Module-2 (MRM-2), a Russian module on the International Space Station, does not meet its requirements for micrometeoroid and orbital debris probability of no penetration (PNP). To document this condition, the primary Russian Federal Space Agency ISS contractor, S.P. Korolev Rocket and Space Corporation-Energia (RSC-E), submitted an ISS non-compliance report (NCR) which was presented at the 5R Stage Operations Readiness Review (SORR) in October 2009. In the NCR, RSC-E argued for waiving the PNP requirement based on several factors, one of which was the risk of catastrophic failure was acceptably low at 1 in 11,100. However, NASA independently performed an assessment of the catastrophic risk resulting in a value of 1 in 1380 and believed that the risk at that level was unacceptable. The NASA Engineering and Safety Center was requested to evaluate the two competing catastrophic risk values and determine which was more accurate. This document contains the outcome of the assessment.
The 2015 Sensorimotor Risk Standing Review Panel (from here on referred to as the SRP) participated in a WebEx/teleconference with members of the Human Health Countermeasures (HHC) Element, representatives from the Human Research Program (HRP), NASA Headquarters, and NASA Research and Education Support Services (NRESS) on December 17, 2015 (list of participants is in Section VI of this report). The SRP reviewed the new Evidence Report for the Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Spaceflight (from here on referred to as the 2015 Sensorimotor Evidence Report), and also received a status review of the Risk. The opening section of the 2015 Sensorimotor Evidence Report provides written descriptions of various incidents that have occurred during space missions. In most of these incidents, the main underlying contributing factors are not easy to identify unambiguously. For example, in section 1.9, a number of falls occurred while astronauts were walking on the moon. It is not clear to the SRP, however, why they fell. It is only possible to extrapolate from likely specific psychophysical or physiological abnormalities, but how these abnormalities were determined, and how they were directly responsible for the falls is unclear to the SRP. Section 2.1.2 on proprioception is very interesting, but the functional significance of the abnormalities detected is not clear. The SRP sees this as a problem throughout the report: a mapping between the component abnormalities identified and the holistic behaviors that are most relevant, for example, controlling the vehicle, and locomotion during egress, is generally lacking. The SRP thinks the cognitive section is too strongly focused on vestibular functioning. The SRP questions the notion that the main cognitive effects are mainly attributable to reversible vestibular changes induced by spaceflight. The SRP thinks that there can also be independent cognitive effects. The Functional Task Test (FTT) protocols and the Field Test are particularly valuable. The conclusion is that the unloading of major postural muscles experienced during spaceflight plays a central role in the alteration of functional task performance and balance control. This conclusion stands in contrast with the statements in other parts of the document that emphasize the role of vestibular changes on these functions. It would help to more fully integrate these two views on the predominant effects of spaceflight. Although the SRP thinks the countermeasures section is interesting, the proposed countermeasures are not well integrated with the abnormalities described in previous sections. The SRP thinks it would help enormously to have explicit links among each abnormality, its 2015 Sensorimotor Risk SRP Evidence Review Final Report 2 overall importance/impact on function, and the appropriate countermeasure that can be implemented to maintain adequate functioning.
The Risk, Responsibility, and Performance Matrix (RRP Matrix) is the energy savings performance contract (ESPC) document that focuses on 16 areas of risks and responsibilities in an ESPC project. The RRP Matrix summarizes and documents the contractor (energy service company, i.e., ESCO) and ordering agency’s agreements about allocating risks and responsibilities – to the ESCO, to the ordering agency, or shared. Ordering agencies and ESCOs should be mindful, however, that the ESCO remains responsible for achieving energy savings guaranteed under the ESPC, notwithstanding the allocations of risks, responsibilities, and performance.
Risk Registers for major subsystems completed according to the methodology described in the Risk Management Plan [DE-EE0008627 D1.2 Risk Management Plan PD v1.1 07-19-2019.pdf], also included here.