Water and Steam Chemistry Division, Bhabha Atomic Research Centre Facilities, Kalpakkam, Tamil Nadu, India.
Biofouling. 2009 Oct;25(7):581-91. doi: 10.1080/08927010903016543.
This article discusses aspects of biofouling and corrosion in the thermo-fluid heat exchanger (TFHX) and in the cooling water system of a nuclear test reactor. During inspection, it was observed that >90% of the TFHX tube bundle was clogged with thick fouling deposits. Both X-ray diffraction and Mossbauer analyses of the fouling deposit demonstrated iron corrosion products. The exterior of the tubercle showed the presence of a calcium and magnesium carbonate mixture along with iron oxides. Raman spectroscopy analysis confirmed the presence of calcium carbonate scale in the calcite phase. The interior of the tubercle contained significant iron sulphide, magnetite and iron-oxy-hydroxide. A microbiological assay showed a considerable population of iron oxidizing bacteria and sulphate reducing bacteria (10(5) to 10(6) cfu g(-1) of deposit). As the temperature of the TFHX is in the range of 45-50 degrees C, the microbiota isolated/assayed from the fouling deposit are designated as thermo-tolerant bacteria. The mean corrosion rate of the CS coupons exposed online was approximately 2.0 mpy and the microbial counts of various corrosion causing bacteria were in the range 10(3) to 10(5) cfu ml(-1) in the cooling water and 10(6) to 10(8) cfu ml(-1) in the biofilm.
本文讨论了核试验反应堆中热流体热交换器（TFHX）和冷却水系统中的生物污垢和腐蚀问题。在检查过程中，发现超过 90%的 TFHX 管束被厚厚的污垢沉积物堵塞。污垢沉积物的 X 射线衍射和穆斯堡尔分析都表明存在铁腐蚀产物。结节的外表面显示出钙和镁碳酸盐混合物以及氧化铁的存在。拉曼光谱分析证实了方解石相中存在碳酸钙水垢。结节的内部含有大量的硫化亚铁、磁铁矿和铁氧氢氧化物。微生物分析表明，铁氧化菌和硫酸盐还原菌的数量相当多（沉积物中每克有 10(5)到 10(6)个菌落形成单位）。由于 TFHX 的温度范围在 45-50°C 之间，因此从污垢沉积物中分离/检测到的微生物群被指定为耐热细菌。在线暴露的 CS 优惠券的平均腐蚀速率约为 2.0 mpy，冷却水中各种腐蚀性细菌的数量在 10(3)到 10(5)cfu/ml 之间，生物膜中的数量在 10(6)到 10(8)cfu/ml 之间。
