Verdantas (formerly Alden Research Laboratory) conducted qualification testing of seven SCRAM valves critical to reactor safety systems. The objective was to validate valve performance under design-basis conditions, ensuring compliance with nuclear QA requirements per 10 CFR 50 Appendix B and ANSI/NQA-1 standards. Testing was performed in a custom-built hydraulic test loop designed to replicate plant operating conditions, including pressures up to 3000 psig.

The program included:

• Hydrostatic Pressure Testing: Verification of valve body integrity and actuator housing leak tightness under static pressure conditions.
• Actuator Set Point Calibration: Measurement and adjustment of pneumatic actuator trip pressures to confirm alignment with design specifications.
• Dynamic Response Analysis: High-speed data acquisition captured valve stroke times during simulated SCRAM events, ensuring rapid closure within required limits.
• Seat Leakage Evaluation: Quantification of leakage rates across valve seats under differential pressure, using calibrated flow instrumentation.
• Instrumentation & QA: All sensors (pressure transducers, displacement sensors, and strain gauges) were calibrated to meet ±1% uncertainty requirements. Data acquisition was performed at high sampling rates (≥1kHz) to capture transient events accurately.

Throughout the campaign, iterative adjustments, such as diaphragm bolt torquing, packing gland tightening, and seal cleaning, were implemented to achieve compliance. Post-test inspections confirmed no structural degradation or abnormal wear. Six of seven valves met all acceptance criteria; the remaining valve required corrective action for actuator performance prior to final approval.

This rigorous, data-driven approach provided the client with validated performance metrics and full traceability under a nuclear-grade QA program, ensuring these safety-critical components are qualified for reliable service in reactor SCRAM systems.