Integrated System Test Facility

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IST Attributes and Capabilities

The current IST facility represents an investment of over $30 million. High fidelity systems, process equipment, control and data acquisition system, and process instrumentation comprise the facility enabling separate effects and integrated system testing.

Learn more about the IST facility here.

Some of the key features of the IST include:

  1. Core Heaters – The IST heater bundle consists of 60 heaters, each containing one Inconel filament designed with an axial cosine heat flux profile, multiple (in some cases four) thermocouples, and a monel sheath.
  2. Steam Generator – The IST steam generator is a 19 tube (alloy 690) once through Babcock and Wilcox designed test-ready steam generator.
  1. Pressurizer and Emergency Core Cooling System – The pressurizer of the IST contains two connections to an emergency core cooling system. These connections lead to depressurization trains that flow to either a sparge nozzle in a 105-foot storage tank or directly to a pressure controlled containment simulation tank. Each location is capable of receiving RCS system maximum pressure, temperature, and “break” flow.
  1. Balance of Plant – The BOP at IST contains a complete feed and steam system with the ability to control water temperatures at the inlet to the steam generator with fine control from ambient to over 400°F.
  1. Reactor Coolant Inventory and Purification – RCIP system contains a high-pressure positive displacement pump capable of providing flow for letdown and make-up of the RCS and a low-pressure pump designed for long-term decay heat cooling.
  1. Test control algorithms – Test control algorithms are an important part of nuclear grade testing. Using algorithms ensures the operator – test interface does not confound the data coming from a test and allows the operator to maintain focus on plant safety. Algorithms give the researcher the ability to extract data and make decisions based on that data knowing there is no masking influence on the results.
  1. Quality Program – The IST instrument “data stream”; defined as signal inception at the instrument level, through communication architecture, conversion to digital data (temperature measurements), data acquisition and finally in storage media has been evaluated and documented using techniques from NQA-1 / 10 CFR Appendix B to Part 50.
  1. RELAP 5-3D Model of the IST – A RELAP5 3-D model has been constructed to accurately represent the conditions in the systems of the IST. Ancillary benefits including pre-test predictions, test planning and training, test procedure development, and test analysis
  1. Additional Test Equipment (potential upgrades)

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5’ removable test section

  • A five foot long, four-inch diameter schedule 160 stainless steel removable section immediately above the core heaters can be replaced with  test sections including but not limited to:
  • Sapphire window installation for optical access to process fluid
  • Test heater installed within 5’ test fixture, separately heated to investigate corroded sheathing / materials.
  • Use this section to create a slip-stream of flow from the top of the core for tertiary loop investigations with localized boundaries to lift cleanliness requirements of the IST RCS. Addition of PIV required materials, dyes, chemicals into tertiary loop.
  • A five-inch diameter test port is installed in a perpendicular flange to the RCS where the riser spills over to the steam generator directly below the pressurizer. This area contains dynamic flow regimes from normal operation to design basis event scenarios. This test port allows access to this are for additional instrumentation installation and can accommodate, like the 5’ pipe above the core, optical windows for advanced instruments. This area was originally designed to install and remove thermocouples that would extend through the primary side of the steam generator for heat transfer coefficient data gathering. This hardware has not yet been installed and is on location at the CAER.

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5” blind flange

  • Coupled with the test location at the bottom of the riser / top of the core this location can provide detailed investigations into the fluid process conditions within the RCS.
  • Flow, pressure, and temperature measurements in single and two-phase conditions can be assessed.
  • During transient tests where the top of the RCS / pressurizer is open for depressurization this location contains superheated steam.
  • Flanged steam lines from the exit of the steam generator to the main condenser are convenient locations to remove a steam for investigative and performance-based research.







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