B-1-(i)Appendix 1 - HSV-2024-043-CA01 Condition assessment - Factorydale
10 passages
1.1.3 Recollections of the incident in December 2023 One of the PLT during our site assessment explained the incident. He reported that he was called to investigate why the power was decreasing. He saw that the wicket gate controls were tr...
AI summary A PLT investigated a December 2023 incident where turbine power decreased despite wicket gate controls attempting to open. The rpm remained steady, but controls failed to respond, accompanied by grinding noises. The turbine was shut down and found in the same damaged state. Don confirmed these observations.
Wicket Gate mechanism The mechanism is operated by a hydraulic governor, which operates a rotating shaft and moves two pairs of levers, a common arrangement on units of this age. Figure 7: Wicket gate mechanism in 3D Figure 8: Unit fully a...
AI summary The Wicket Gate mechanism is operated via a hydraulic governor and rotating shaft, with corrosion observed on components. A wooden branch found in the scroll case indicates potential foreign object intrusion, though it may not have caused the damage. Pins connecting arms to the operating ring show past replacement due to failures, with no current signs of deformation.
Wicket gate 08 Figure 18: Wicket gate 08, half attached to the pivot shaft Figure 19: Wicket gate 8, half attached to the control link Of all the Wicket Gates, this one, and the missed number 14, are key to understanding one of the causes...
AI summary Wicket Gate 08 failed due to an impact that broke the gate into two pieces, leaving the bronze control link intact. The link's design as a 'mechanical fuse' allowed it to remain in place, while the gate's casting quality, previously discussed in metallurgical tests, is highlighted as a contributing factor.
3.4 Governor The hydraulic governor is the original from 1968, when the plant was commissioned to its current state. Figure 31: Woodward Governor Figure 32: Woodward Governor, additional views We couldn't find technical specs of this gover...
AI summary The 1968 hydraulic governor has undergone undocumented modifications and repairs over 60 years, showing oil leaks and safety risks. Emerson still services these governors, but technical specs were unavailable during the report. The governor functioned properly before the 2023 failure, though maintenance records were incomplete.
Table 22: HydroAMP - Performance Scoring Performance Scoring Observations (Criteria) Condition Indicator Score Off-line and on-line response and stability normal, governor free from hunting, accuracy of frequency within < 0.2 Hz, synchroni...
AI summary The performance scoring table evaluates the governor's response and stability, with scores ranging from 1 to 3 based on criteria like frequency accuracy and remote start capability. Despite not being designed for remote start, the governor performs well with local commands, resulting in a score of 2.
Implement Continuous Monitoring Systems: Install continuous monitoring systems for critical components such as the turbine, generator, and hydraulic systems. Focus on monitoring vibration, temperature, pressure, and flow rates. Immediate d...
AI summary The text advocates for installing continuous monitoring systems on critical infrastructure components like turbines and generators to track parameters such as vibration and temperature. This proactive approach aims to detect issues early, preventing failures and ensuring operational safety.
Initiate Immediate Inspections: Conduct thorough inspections of all critical components, particularly those identified as high-risk in the assessments (e.g., turbine seals, generator bearings, and hydraulic systems). Document any findings...
AI summary The text emphasizes conducting immediate inspections of high-risk infrastructure components (e.g., turbine seals, generator bearings) to identify issues early, prevent unplanned outages, and ensure operational reliability through timely interventions.
Upgrade Control and Automation Systems: Following the turbine replacement, upgrade the control systems to include modern digital controls, remote monitoring, and automated safety shutdowns. Integrate these systems with the new turbine for...
AI summary The document outlines the necessity to upgrade control systems following turbine replacement, emphasizing modern digital controls, remote monitoring, and automated safety shutdowns. It highlights that the current system, installed in 2020 and tested in 2023, is outdated and lacks remote control capabilities, which could compromise operational efficiency, safety, and reliability.
CONCLUSION The condition assessment of the Factorydale Hydropower Plant reveals that while certain components remain operational, the plant's overall health is compromised by aging infrastructure and significant damage to critical componen...
AI summary The Factorydale Hydropower Plant requires urgent turbine replacement due to aging infrastructure and critical damage. While a generator rewind extends its lifespan, ongoing maintenance is vital. Three options are proposed: like-for-like turbine replacement, installing a modern unit, or decommissioning. The report advocates turbine replacement for continued efficient operation.
RISK ASSESSMENT Risk Number System Component Risk Scenario Description Likelihood (1-5) Impact (1- 5) Risk Level (Likelihood x Impact) Mitigation Measures 1.5.7 Turbine Turbine Seal Safety and Environmental Impact: Sudden Seal Failure Lead...
AI summary The risk assessment identifies a potential risk related to turbine seal failure, which could lead to flooding and damage to downstream equipment. Mitigation measures include regular inspections, backup seals, and emergency response training.
B-1-(iii)Appendix 3 - HSV-2024-043-SREP02 Feasibility Study
12 passages
1.2 Root Case Analysis: Conclusions - The most likely scenarios were reviewed based on evidence gathered on-site, laboratory analyses, and computer simulations. The evaluation strongly indicates that a large object passed through the turbi...
AI summary The root cause analysis concludes that a large object caused catastrophic turbine failure, exacerbated by substandard cast iron and design flaws in wicket gates and blade attachments. The analysis highlights material inadequacies and engineering shortcomings that contributed to irreversible damage.
2.3.5 Generator The proposed project involves the replacement of the existing electric generator at Factorydale with a new synchronous AC generator, rated between 650 kW and 750 kW, operating at 2300 V, 514 rpm, with 14 poles and 60 Hz fre...
AI summary The proposal involves replacing Factorydale's existing generator with a new 650-750 kW synchronous AC generator, enhancing efficiency and sustainability while adhering to IEC/CSA standards. Key requirements include humidity control, corrosion resistance, SCADA integration, and compliance with environmental and operational standards for reliability under transient conditions.
2.3.6 Switchgear The Factorydale hydropower project includes the replacement and upgrade of the existing switchgear system, ensuring comprehensive protection, control, and isolation of electrical systems associated with the new hydro-gener...
AI summary The Factorydale hydropower project involves upgrading switchgear to ensure electrical system protection, control, and isolation. Compliance with IEC and CSA standards is mandatory, with advanced protection mechanisms and detailed maintenance protocols. Grounding systems and surge protection are emphasized for reliability.
2.3.7 SCADA, Control, Automatization, Protection and Measurement The proposed Factorydale hydropower project involves upgrading the existing SCADA, Control, Automation, Protection, and Measurement systems. The upgrade will include a comple...
AI summary The Factorydale hydropower project proposes upgrading SCADA, control, automation, protection, and measurement systems. Key upgrades include PLC-based panel replacement, remote communication, machine learning for predictive maintenance, multifunctional relays, advanced power quality meters, redundant SCADA infrastructure, and compliance with IEC standards to enhance operational efficiency, reliability, and safety.
4.1 Grid Modernization - Improving the utilization and efficiency of existing assets. The project modernizes a hydropower facility, enhancing the efficiency of existing infrastructure. Upgrades to the turbine, generator, and draft tube opt...
AI summary The project modernizes a hydropower facility to enhance efficiency, improve system reliability through advanced monitoring, and increase renewable energy integration. Upgrades include turbine and generator improvements, SCADA systems, and real-time monitoring to reduce losses, ensure reliability, and support decarbonization goals.
4.2 Customer Value The Factorydale Hydropower Plant Refurbishment delivers significant value to ratepayers by improving affordability, reliability, and environmental sustainability while supporting broader community benefits.
AI summary The Factorydale Hydropower Plant Refurbishment enhances affordability, reliability, and environmental sustainability while delivering community benefits. It positions hydropower as a key resource for ratepayer value through improved operational efficiency and reduced environmental impact.
• Improved Reliability and Resiliency o Modern controls, SCADA integration, and advanced protection systems enhance operational reliability, reducing the risk of outages. Real-time monitoring enables proactive maintenance, ensuring uninter...
AI summary Modern controls, SCADA integration, and advanced protection systems enhance grid reliability and resiliency by reducing outage risks, enabling proactive maintenance, and improving stability. Substation upgrades support renewable energy integration and load redirection, strengthening grid capacity.
4.5 Societal Benefits The Factorydale Hydropower Plant Refurbishment delivers societal benefits by enhancing energy affordability, reliability, and accessibility for Nova Scotians, especially those that are part of the Berwick Electric Com...
AI summary The Factorydale Hydropower Plant Refurbishment enhances energy affordability, reliability, and accessibility for Nova Scotians, particularly those on the Berwick Electric Commission (BEC) grid. It reduces energy costs for vulnerable households, improves grid reliability for rural customers, and enables future renewable energy initiatives like community solar gardens and battery storage, reducing energy poverty.
• Addressing Energy Affordability and Security o By modernizing the Factorydale plant, the project ensures the continued supply of renewable, cost-effective energy to the grid, directly benefiting communities that rely on affordable electr...
AI summary Modernizing the Factorydale plant ensures renewable, cost-effective energy supply, benefits communities with affordable electricity, and reduces outage risks for vulnerable customers.
5.1 Grid Modernization - Improving the utilization and efficiency of existing assets. - o Turbine-Generator Efficiency: Increase from 60% to 90% using hydropower efficiency tests (power output vs. hydraulic input). - o Unplanned Downtime R...
AI summary The Grid Modernization section outlines initiatives to improve asset efficiency (e.g., increasing turbine-generator efficiency from 60% to 90%), enhance grid reliability (e.g., reducing SAIDI by 30%), and boost renewable integration (e.g., achieving >55% renewable penetration). Metrics include SCADA/AMI analytics, PPA data, and generation reports.
5.2 Customer Value - Reliability & Service Quality. - o Outage Reduction (SAIDI): Reduce customer outage duration. - Target: 30% reduction in outage hours (1.5 to 1.05 hrs/customer annually). - Measurement: Utility event logs, SCADA tracki...
AI summary The section outlines targets for reducing outage duration (30% reduction in SAIDI) and improving power quality (95% voltage compliance). It also aims to increase customer satisfaction from 85% to 92% through annual surveys. Metrics include SCADA tracking, utility logs, and complaint data.
Key Risks Probability Impact Risk Mitigation Strategies Inaccurate initial schedules Medium High Thorough schedule validation, include contingencies, regular progress reviews. Delays in regulatory approvals Medium Medium Early engagement w...
AI summary The document outlines key risks associated with a project, including inaccurate schedules, regulatory delays, scope changes, cost escalations, and supply chain disruptions. Mitigation strategies include schedule validation, early regulatory engagement, fixed-price contracts, and cybersecurity protocols. Safety and natural disaster risks are also addressed with specific plans and insurance.
B-3-(i)Appendices - Redacted
12 passages
2024 DAM SAFETY REVIEW
AI summary The document outlines the 2024 Dam Safety Review, focusing on the assessment and evaluation of dam infrastructure to ensure safety and compliance with regulatory standards.
4.1.3 OPERATIONS, MAINTENANCE & SURVEILLANCE The BEC does not have any policies or procedures grouped in an operations, maintenance and surveillance (OMS) manual at Factorydale Dam. But there are standard practices that operators follow in...
AI summary The BEC lacks an OMS manual at Factorydale Dam, relying on standard practices that need documentation for safety. Issues include limited understanding of upstream controls, discontinuous lake level monitoring, lack of debris monitoring, and undefined TARP levels. Independent verification of inspections is recommended to ensure dam safety.
Freeboard compliance in establishing the MFL assumes stoplogs are removed from the spillway prior to the onset of the storm. During the IDF event, with all stoplogs removed, the concrete dam is overtopped by +0.62 meters and the entombed p...
AI summary The text discusses freeboard compliance and the impact of stoplog removal on dam safety during an IDF event. With stoplogs removed, the concrete dam and entombed parapet are overtopped by specific amounts, while not removing them could lead to a 210 mm increase in reservoir stage.
Table 4.4 Results of Sliding Stability Analysis Load Condition Required Factor of Factor of Safety Safety Section A (SCP Anchor) Section B (Rockbolts) Spillway Usual 1.5 1.9 1.8 2.1 Usual (No Ice) 1.5 3.2 22 3.1 Unusual (Flood) 1.3 1.7 4.9...
AI summary The stability analysis of the dam and spillway shows compliance with CDA guidelines under usual, unusual, and extreme load conditions. Sensitivity analysis highlights potential risks if rock anchors relax or the concrete-bedrock interface deteriorates, but no current signs of these issues were observed. Some areas of the dam remain at risk due to lack of post-tensioning.
TECHNICAL MEMORANDUM– CDA GUIDELINES Project: 2024 Dam Safety Review Factorydale Hydroelectric Development Subject CDA Dam Safety Review Synopsis Author: Perry Mitchelmore, P.Eng. Date: December 10, 2024 The purpose of this Technical Memor...
AI summary This technical memorandum summarizes the application of the Canadian Dam Association (CDA) Dam Safety Guidelines to the 2024 Dam Safety Review for the Factorydale Hydroelectric Development. The CDA Guidelines provide a non-prescriptive framework for assessing dam safety, including classification based on failure consequences, condition assessments, design adequacy evaluations, and management practices.
2 CONDITION ASSESSMENT Overall, Factorydale Dam is in Fair condition, with minor deficiencies, but should continue to operate for the intended purpose. The concrete dam and spillway was in Fair condition. There is some spalling on the 2008...
AI summary Factorydale Dam is in Fair condition with minor deficiencies, including spalling, seepage, and debris accumulation. Some structural elements are in good condition, but there are concerns about overtopping and lack of public safety measures. The BEC has not completed a PSAD risk assessment, and the dam lacks signage or barriers to prevent public access.
Photo # Location Priority Defect Recommended Mitigation 14 Catwalk Medium Loose nut on catwalk plate, second pier from left (looking downstream) Secure nut properly to baseplate 20 Right Dam Section High Overtopping at the right dam sectio...
AI summary The document outlines various structural issues and recommended mitigations for a dam and associated infrastructure, including loose nuts, seepage, erosion, and public access risks. Priority levels are assigned to each issue, and mitigation strategies are proposed.
High Priority action; - The vegetation should be cleared periodically for better inspection of the abutments and downstream face of the right dam section. - A Public Safety Around Dams (PSAD) risk assessment is required to form the basis o...
AI summary The text outlines high-priority actions for dam safety, including periodic vegetation clearing, conducting a Public Safety Around Dams risk assessment, and installing a timber parapet as part of a 2008 remedial design.
3.3.5 SCS Unit Hydrograph The unit hydrograph shape controls the portion of rainfall volume that will occur before the peak of the inflow hydrograph. The SCS has a unit hydrograph with 37.5% of unit runoff occurring before the peak flow as...
AI summary The SCS unit hydrograph is defined by a standard shape where 37.5% of runoff occurs before the peak flow. The peak rate factor (PRF) reflects this. Lag time, calculated using geometric subbasin values and approximated by 0.6 times the time of concentration, is 4.6 hours for the Factorydale Dam Watershed.
4.4.2 Failure at Factorydale Dam/Spillway Dam breach results are shown in [Table 4.5.](#page-0-79) The results compare Factorydale Dam's performance under two primary scenarios: Fir-weather Failure and Flood-induced Failure. Each scenario...
AI summary The text discusses the results of dam breach simulations at Factorydale Dam under two scenarios: Sunny Day Failure and Rainy Day Failure. It highlights the rapid failure times and the significant increase in peak breach flow rates and outflow volumes during different flood events, including the AEP100 and PMF scenarios.
Table 6 : Runup and Setup Calculations Freeboard Normal Minimum Comments Wind Setup - S 0.03 m 0.01 m Hourly winds Surf Similarity Factor - E p 1.0 1.9 Correction Factors A 1.6 1.6 C 0 0 γr 1 1 γb 1 1 γh 1 1 Angle of Incidence - β 0 ° 0 °...
AI summary Table 6 provides runup and setup calculations, including wind setup, surf similarity factors, correction factors, and runup values. These calculations are essential for assessing flood risks and designing infrastructure to withstand potential water levels.
(4) Extreme Load Condition (Seismic) Horizontal Loads Name Pressure (kPa) Force (kN) Moment (kN m) Normal H2O HydrostaticNOL -54.9 -153.8 -287.1 Normal H2O HydrostaticTWN 0.0 0.0 0.0 SoilUpstream Active -26.2 -14.0 -14.9 SoilDownStream Act...
AI summary This section outlines the analysis of extreme load conditions, specifically seismic loads, on a structure. It presents detailed tables of horizontal and vertical loads, including pressures, forces, and moments, and evaluates factors of safety for sliding and overturning under various conditions such as usual, unusual (flood and wave), and extreme (earthquake). The appendix likely provides further technical details or supporting documentation.