Evaluation of Automation Trustworthiness in Nuclear Power Plants: A Risk-Informed Approach using Probabilistic Validation and Integrated Probabilistic Risk Assessment

In the pursuit of enhanced efficiency and operational safety, the U.S. nuclear industry is progressively integrating automation technologies into Nuclear Power Plants (NPPs). To make informed decisions about large-scale investments in these technologies, stakeholders require robust evidence of their transparency, trustworthiness, and operational acceptability. This study presents a risk-informed approach to evaluate automation trustworthiness, combining an advanced Integrated Probabilistic Risk Assessment (I-PRA) methodological framework with a Probabilistic Validation (PV) methodology. This paper is part of an ongoing project, funded by the Department of Energy (DOE) under the Nuclear Energy University Program (NEUP), which aims to develop a probabilistic validation and risk importance ranking methodology for automation trustworthiness and transparency in NPPs. The I-PRA framework, developed by the PI's team in previous studies, connects simulation models of underlying physical and social phenomena with the existing plant PRA model through a probabilistic interface. I-PRA adds realism into the risk estimation by explicitly incorporating time and space into the underlying models while avoiding significant changes to the plant PRA model and its associated costs (e.g., peer review). In this project, I-PRA is advanced by adding or advancing automation-related modules to enable a clear tracing and capture of relationships between the plant risk metrics and input parameters associated with the underlying physics, automation, and human performance. A Global Importance Measure (GIM) method is added to I-PRA to rank significant sources of uncertainty at the level of underlying physics, automation, and human performance concerning their contribution to the plant risk uncertainty. The PV methodology lies at the core of our approach for evaluating automation trustworthiness. It characterizes and propagates the uncertainties associated with the human-automation-physics coupling, with the degree of automation trustworthiness measured by the magnitude of epistemic uncertainty associated with the automation output. Execution of the PV methodology for evaluation of automation trustworthiness in NPPs requires that the uncertainties from the underlying automation model level be propagated up to the level of plant risk metrics, which necessitates a computational platform that is achievable by leveraging the advanced I-PRA framework. The acceptability of the degree of automaton trustworthiness for a specific automation application is evaluated against predefined acceptance criteria that can be found available at one or more levels of the system hierarchy (e.g., automation output level or plant risk metric level). The PV methodology, in conjunction with advanced risk importance ranking results, provides an efficient algorithm to enhance automation trustworthiness. To demonstrate the feasibility and practicality of the advanced I-PRA framework and the PV methodology, this paper presents a case study centered on an AI-based automated firewatch system. By integrating the advanced I-PRA framework with the PV methodology, the proposed approach offers a holistic evaluation of automation technologies' trustworthiness, considering complex interactions among human operators, automation technologies, and the evolution of physical phenomena in NPPs. This comprehensive evaluation will assist in making informed decisions about the deployment and operation of automation technologies in NPPs, ultimately contributing to the enhancement of plant safety and efficiency

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

The patterns of clinical presentations of cerebellar syndromes among adult Sudanese patients

Cerebellar syndromes are one of the commonest neurological diseases.Objectives: To study the patterns of clinical presentations of cerebellar syndromes and to identify the possible causes.Methods: This is a prospective hospital based, cross-sectional study. One hundred adult Sudanese patients with cerebellar syndromes were included in the study during the period from January 2006– January 2007.Results: The most common age group affected was 18 – 25 years. Male to female ratio was 1.5: 1 unsteadiness on walking was the most common symptom (83%). Gait-ataxia was the most common sign (83%). Cerebrovascular disease was the most common aetiology (25%).Conclusion: Cerebellar syndromes are not rare in Sudan. However, they were diagnosed more commonly at the central regions of the country probably because of more awareness of patients and better facilitiesfor diagnosis. The age of onset, the male predominance, the presentation and clinical findings were not different from reported literature. This also goes for the common causes apart from alcohol which is a strikingly rare as a cause in this study and could be accounted for the implementation of Elshariya (Islamic laws) Laws in Sudan.Keywords: ataxia, dysmetria, disdiadochokenesis, decomposition, nystagmus, dysarthria

Search for new physics in the multijet and missing transverse momentum final state in proton-proton collisions at √s=8 Tev

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Measurement of Higgs boson production and properties in the WW decay channel with leptonic final states

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Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112

Study of double parton scattering using W+2-jet events in proton-proton collisions at √s=7 TeV

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Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Measurements of the tt¯ charge asymmetry using the dilepton decay channel in pp collisions at √s=7 TeV

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