Do you know what a nuclear outage schedule means and why it’s crucial? In this article, we’ll delve into the significance of statutory outages, the planning involved, and the role of contractors. Using the Heysham 2 Power Station’s 2021 outage season as a case study, we’ll explore the activities carried out and how they overcame challenges posed by Covid-19. We’ll also discuss the timing and safety measures of refueling outages in the United States. Join us to unravel the intricacies of nuclear outage schedules and their importance in safe and efficient power generation.

Importance of Nuclear Outage Schedule

The importance of the nuclear outage schedule lies in ensuring the safe and effective management of repair, maintenance, and testing activities during designated periods. Proper preparation strategies are crucial to ensure regulatory compliance and the coordination of outage activities. By adhering to the schedule, equipment maintenance can be carried out efficiently, minimizing downtime and maximizing plant performance. Safety measures are also a key aspect of the outage schedule, as they ensure the well-being of workers and the protection of the environment.

One of the main reasons for the outage schedule is to comply with regulatory requirements enforced by organizations such as the Office for Nuclear Regulation (ONR). These regulations aim to maintain the highest level of safety in nuclear power plants. By carefully planning and coordinating outage activities, plant operators can meet these requirements while ensuring the availability and cost-effectiveness of the plant.

Additionally, the outage schedule allows for the implementation of proper equipment maintenance. During outages, equipment can be inspected, repaired, and maintained to ensure optimal performance. This includes updating or exchanging equipment that may be outdated or no longer functioning properly. By addressing maintenance needs during scheduled outages, operators can minimize the risk of equipment failures and prolong the lifespan of critical components.

Planning and Execution of Nuclear Outage Activities

To plan and execute nuclear outage activities, you need careful coordination and preparation. The success of these activities relies on effective preparation and coordination of resources, as well as the implementation of safety measures. One important aspect of outage planning is the identification of equipment that may need updates or replacement. This includes managing obsolescence, especially when original equipment manufacturer (OEM) resources are unavailable. A detailed plan is prepared in advance for each outage period to ensure the safety of the plant throughout the process.

During the outage, various tasks are performed to maintain and improve the plant’s performance. This may include software updates, hardware refurbishment, and routine maintenance. The execution of these tasks requires precise coordination and adherence to safety measures. It is crucial to ensure that all activities are carried out efficiently and effectively to optimize outage performance.

Role of Contractors in Nuclear Outage Periods

During a nuclear outage period, you rely on contractors to play a crucial role in ensuring the success and efficiency of outage activities. Here are three key aspects of the role that contractors play:

• Contractor selection: Choosing the right contractors is essential for outage management. Contractors with specialized skills and experience in nuclear power plant maintenance and repair are preferred. Thorough evaluation and vetting processes are used to select contractors who can effectively contribute to the outage activities.
• Collaboration benefits: Collaborating with contractors brings numerous benefits to the outage process. Contractors bring fresh perspectives, innovative ideas, and different approaches to problem-solving. This collaboration fosters knowledge sharing and can lead to improved outage performance.
• Cost effectiveness and obsolescence management: Engaging contractors can be cost-effective compared to maintaining an in-house workforce solely for outage activities. Contractors can provide specialized services and expertise at lower costs. Additionally, contractors can help manage obsolescence issues by offering solutions for outdated equipment and technologies.

Case Study: Heysham 2 Outage Season 2021

In the Heysham 2 Outage Season 2021, you successfully completed software updates, hardware refurbishment, and routine maintenance. Despite facing challenges, such as the ongoing COVID-19 pandemic, you implemented outage safety measures to ensure the well-being and productivity of the team. Collaboration within the outage team was a key factor in the success of the outage season. Detailed software development and off-site refurbishment programs were carried out prior to the outage, ensuring that all necessary modifications were implemented and approved by EDF Energy. During the outage, confidence testing was performed successfully. In terms of maintenance tasks, various activities were undertaken, including fan and filter replacement, cubicle bonding, and compiling reports. The team’s dedication and adherence to safety protocols allowed for the safe and efficient completion of the outage season. Moving forward, the team continues to support EDF Energy with various projects, offering industrial electronic repair, refurbishment, and testing services to new organizations.

Timing and Duration of Nuclear Refueling Outages

You can expect nuclear refueling outages to occur at regular intervals, typically every 18 to 24 months. These outages are planned to coincide with periods of low electricity demand, usually in the spring and fall. The Energy Information Administration (EIA) tracks these outages based on data from the Nuclear Regulatory Commission (NRC). In the spring, peak outages occur in mid-April, with an average capacity out of service ranging from 15 GW to over 23 GW. Fall outages peak in late October, with a similar capacity offline as in the spring.

During refueling outages, safety precautions are a top priority. Plants schedule facility upgrades, repairs, and maintenance work while ensuring the protection of workers and the environment. For example, the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) undergoes routine refueling with strict safety measures in place. Spent fuel emits a luminescent blue glow due to Cherenkov radiation, highlighting the need for safety protocols.

The duration of refueling outages has seen a significant decrease over the years. In 1997, the average outage duration in the U.S. was over 80 days. However, continuous improvement efforts have reduced the average duration to about 33 days by 2002. While the duration has fluctuated, it has remained in the 30- to 46-day range over the past two decades, according to data from Statista.

To ensure effective refueling outage preparation and execution, the Electric Power Research Institute (EPRI) has issued guidance. Their technical report provides industry best practices for planning, preparation, and execution of nuclear power plant refueling outages. EPRI emphasizes the report as a consistent reference for outage team members.

EPRI has also developed ChemWorks Tools, including a shutdown calculator (SDC) module. The SDC tool models shutdown chemistry evolution and predicts cleanup times in pressurized water reactors (PWRs). It has been evaluated and found to provide reliable estimates of cleanup time using operational data, specifically cobalt-58 peak activity. This evaluation was conducted by researchers from Korea Hydro and Nuclear Powers (KHNPs) Central Research Institute.