Biofouling and its control in a tropical coastal power station: A case study

Macrofouling in the cooling circuits of coastal nuclear power stations is an important problem from the operational and safety viewpoints. However, comprehensive studies on settlement, biomass build‐up and response of settled organisms to control measures are very few. This paper presents data on the biofouling problems encountered in the precondenser section of the cooling circuit of a tropical coastal power station and the control measures adopted to alleviate them.

In the Madras Atomic Power Station, development of severe, mussel‐dominated biofouling was noticed in the cooling water intake tunnel, in spite of intermittent chlorination used as a fouling control measure, resulting in serious pressure drop in the cooling water circuits. Switching over to shock dose chlorination, followed by continuous low dose chlorination helped removal of a large quantity of sessile biomass from the tunnel, leading to satisfactory flow performance. The data also indicate the effectiveness of continuous low level chlorination to “flush out”; young mussels without killing them. Since the breeding pattern of mussels in the study area shows two peaks spread over 8–9 months of the year, it is imperative to use uninterrupted chlorination to keep biofouling at acceptable levels.

Key words:

• Biofouling
• coastal power stations
• cooling water
• chlorination
• Perna viridis

Notes

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