The Nuclear Regulatory Commission’s (NRC) Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident states that plants should increase their coping time from the standard 8 hours to 72 hours in an effort to outlast a natural disaster or terrorist attack. The nuclear industry responded with the FLEX strategy which relies on additional, portable equipment to prevent the loss of cooling capability and electrical power. Utilities are moving fast to implement FLEX with almost all U.S. plants installing and training their staff on the new equipment by the end of 2016 according to the Nuclear Energy Institute.
That’s a lot of hours and equipment that plants haven’t previously been required to train on. What’s more, simulator guidelines do not require them to simulate beyond design basis accidents, meaning that your training program is going to have to train your operators and engineers on new procedures related to these recommendations with good ol’ pen and paper and classroom instruction.
Why does an industry that widely recognizes high-fidelity simulation as the most effective way to provide experiential learning for operators and engineers think that personnel can properly train on beyond design basis accidents without it? When you think about it, operators might experience plant startups, shutdowns and other plant normal evolutions that they are also legally required to train on with a high-fidelity nuclear power plant simulator, but take away the power to the entire plant and we assume they’ll be fine having learned what to do via PowerPoint?
Experiential learning can be achieved safely for FLEX and coping strategies with your existing full-scope simulator assuming that you make some updates to reflect the new equipment and procedures. Many plants have already taken this next step knowing that it’s the best way to train and perhaps trying to stay ahead of any future simulator requirements that might be coming.
Training for extended loss of offsite power events
When preparing to train for extended loss of offsite power events, your plant’s training staff must answer some important questions. What new equipment, new operating scenarios, and new communications paths must your operators learn as your plant evolves to respond to potential catastrophic events? How should you improve your simulator to teach them? What are we missing that a walkthrough on a plant referenced simulator might reveal to us?
To answer the larger questions, it might be easier to address some smaller questions centered primarily on the flexible equipment strategy (FLEX) recommended for handling such events. (See our checklist for help.) FLEX depends on providing power and cooling to key systems in the plant through portable diesel generators, portable pumps, and auxiliary water supplies.
Who sets these up? Who operates them? Who controls their operation?
Properly training operators on new equipment and new procedures may require some simulator upgrades. For example, depending on the age of your simulator, it’s possible that your battery and power supply models are over-simplified. While these models are fine for normal operation, shifting loads and optimizing battery discharge rates could be the key to increasing coping time to the recommended 72 hours. How do you train your operators on these important new procedures?
Questions you should ask of your simulator models
In general, it’s likely that you’ll need to upgrade your electrical, communications, and plant piping system models to adequately train your plant’s operators and engineers on the new FLEX equipment and procedures, but here are some questions that you’ll need to ask of your simulator systems:
Electrical Systems Modelling
Electrical systems are key. Can you simulate cross-connecting 480 VAC busses, instrument busses, and power for key individual AC loads? Are you installing new batteries, or upgrading existing batteries? Are you installing new chargers for your batteries? Can you simulate cross-connecting DC busses or batteries? Can you simulate cross-connecting power for key individual DC loads? Can you simulate installing manual cables and operating manual transfer switches to accomplish the cross connections?
Communications Systems Modelling
Have you thought about the modeling of your communication systems? Can you model a failure of the power supplies that enable communications? How long do your Uninterruptable Power Supplies (UPSs) last and can you model their failure in the simulator? How do you charge the radio batteries in the simulator control room and can you model a loss of the charging capability?
Plant Piping Systems Modelling
And finally, what about the plant piping systems? Can you install portable cooling systems? And if so, does your model show their effect in the simulator?
With your existing models, can you accurately train operators for these situations?
Should you upgrade your simulator to adequately train on FLEX equipment?
These are just some of the many questions you’ll need to address. And depending on your answers, you’ll have to upgrade your models and training scenarios accordingly. We’ve compiled a list of 37 questions around your plant’s FLEX equipment installation and your simulator models. Answer them and then you decide.