Zr-2.5%Nb alloy is used as pressure tube material in Indian pressurised heavy water reactors (PHWR). Hydrogen diffusion studies have been carried out in this alloy in the temperature range 523 K-723 K. Samples were prepared by electrolytic hydrogen charging at one end and then subsequent annealing at said temperatures to form a concentration gradient. Neutron radiography and for the first time, metallography techniques have been used for hydrogen content profiling. Calibration studies for hydrogen in Zr-2.5%Nb alloy have also been carried out at Dhruva imaging beamline to determine the absolute hydrogen content from neutron transmission values. The hydride area fraction has been used as the measure of hydrogen content in metallography studies. The absolute hydrogen content for radiography and hydride area fraction for metallography; vs distance data were fitted with error function to obtain diffusivities at various temperatures. The diffusivity data were further processed to obtain the temperature-dependent diffusion coefficients for both techniques in the temperature range of 523 K-723 K. The results obtained from both techniques are consistent, establishing the fact that a simple lab-based technique like metallography can also be used for diffusion studies.

Zr-2.5％Nb合金在印度加压重水反应堆（PHWR）中用作压力管材料。在此合金中，在523 K-723 K的温度范围内进行了氢扩散研究。通过在一端充入电解氢，然后在所述温度下进行退火以形成浓度梯度来制备样品。中子射线照相术以及金相照相技术首次被用于氢含量分析。Zh-2.5％Nb合金中氢的校准研究也已在Dhruva成像光束线上进行，以确定中子传输值的绝对氢含量。氢化物面积分数已用作金相研究中氢含量的量度。射线照相的绝对氢含量和金相照相的氢化物面积分数；距离数据与误差函数拟合得到不同温度下的扩散率。进一步处理扩散率数据以获得这两种技术在523 K-723 K的温度范围内随温度变化的扩散系数。从这两种技术获得的结果都是一致的，这证明了简单的基于实验室的技术（如金相学）可以也可用于扩散研究。