Evaluation of the effect of ion exchange resin on feeder integrity

Lepreau核电站（PLNGS）在出口给料器上安装了一个在线氢气渗出监测仪（来自UNB CNER的HEPro），以监测氢气渗透率，从而监测给料器变薄的速度。初步结果表明，翻新停运期间安装的高铬给料器的总体腐蚀速率明显低于先前安装的低铬给料器。对氢气渗出率的监测表明，探针对初级热传递系统中的化学变化（例如，在加油过程中引入低浓度的溶解氧）很敏感。最近的观察结果之一是，在PHT净化回路中安装新的锂化IX树脂床后，氢气渗出率显著增加（超过两倍）。观察结果表明，由于这种化学变化，给料机疏化率发生了显著变化。高腐蚀率（仍远低于翻新前）持续了一个月，直到计划停运，并在工厂重启后以更高的速度恢复，但此后一直在下降。初步计算表明，新离子交换树脂以足够快的速度从溶液中去除铁，从而显著影响核心出口的欠饱和程度，从而改变流动加速腐蚀速率。**该项目的目的是评估当前离子交换树脂的做法对喂料器完整性的影响，并确定是否可以优化使用的树脂混合物，以降低从溶液中去除的铁量，同时满足活性运输要求。该范围包括对PLNGS HEPro数据（2006年至今）的全面分析，以评估离子交换树脂实践与FAC率之间的联系。这项工作的第二个方面将进一步评估离子交换树脂对铁和成膜胺的吸收特性，这些胺可以用作该站二级系统的添加剂。****

Point Lepreau Nuclear Generating Station (PLNGS) has installed an online hydrogen effusion monitor (HEPro from CNER at UNB) on an outlet feeder to monitor the hydrogen permeation rate and hence the rate of feeder thinning. Initial results have shown that the general corrosion rate of the higher chromium feeders installed during the refurbishment outage is significantly lower than the previously installed low chromium pipes. Monitoring the rate of hydrogen effusion has shown that the probe is sensitive to chemistry changes in the primary heat transport system (e.g. the introduction of low concentrations of dissolved oxygen during fueling). One of these recent observations was a significant increase (more than double) in the hydrogen effusion rate following the installation of a fresh, lithiated IX resin bed in the PHT purification circuit. The observation suggests that the feeder thinning rate changed significantly due to this chemistry change. The elevated corrosion rate (still much lower than pre-refurbishment) persisted for a month, until a planned outage and resumed at the higher rate following plant restart but has since been decreasing. Preliminary calculations suggest that the fresh ion exchange resin is removing iron from solution at a fast enough rate to significantly influence the degree of under-saturation at the core outlet and hence change the flow accelerated corrosion rate.** The objective of this project is to evaluate the influence of current ion exchange resin practices on feeder integrity and to determine if the resin mixtures in use can be optimized to lower the amount of iron being removed from solution while meeting activity transport requirements. The scope includes a full analysis of the PLNGS HEPro data (2006 - present) to evaluate the link between ion exchange resin practices and FAC rates. A secondary aspect of this work will further evaluate the absorption characteristics of ion exchange resins for iron species and for film forming amines that may be used as additives to the station's secondary system.****