Verdantas (formerly Alden Research Laboratory) was engaged to evaluate the performance of a submerged sample holder intended for use in a reactor vessel, where it would be exposed to high temperature, pressure, and single-phase water flow. The client required assurance that the sample holder could withstand flow-induced forces and vibration, maintaining structural integrity and reliable operation.

Verdantas constructed a specialized flow loop, approach/discharge structure, and enclosure for a full-scale mock-up, to simulate the full range of anticipated operating conditions. The design of the flow loop and operational boundary was informed by Verdantas’ secondary CFD analysis. The sample holder and scaled portion of reactor shroud, provided by the client, was instrumented with precision sensors and subjected to comprehensive testing—including baseline flow mapping, instrumentation sensitivity checks, operating map evaluations, long-term exposure, and dynamic impact response assessments.

Results confirmed that instrumentation did not alter the flow field, and that vibration amplitudes increased predictably with flow velocity, without activating unexpected structural modes. Long-term testing at the most adverse conditions revealed no significant loss of bolt pre-load or change in dynamic response, demonstrating the sample holder’s resilience.

The project was executed under a rigorous nuclear QA program, with all measurements and analyses meeting strict uncertainty and calibration requirements. Verdantas’ approach provided the client with clear, data-driven confidence in the sample holder’s ability to perform reliably in its intended environment.