Three-dimensional field studies of thermal backwashing plumes

Journal Article · Fri Jan 01 00:00:00 EST 1982 · Environ. Manage.; (United States)

DOI:https://doi.org/10.1007/BF01866807· OSTI ID:5339388

Hartwell, A D ^[1]; Mogolesko, F J

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1. Sanders Associates, Inc., Nashua, NH

Using specially designed temperature profiling equipment, two surveys were conducted during thermal back-washing operations at Pilgrim Nuclear Power Station to determine the spatial and temporal extent of temperature rises above ambient. Thermal backwashing is a process where biofouling is combated by a heat treatment procedure. Back-washing formed a thermal plume about 5- to 6-ft thick (1.5- to 1.8-m) in front of the intake screenwall. Maximum observed surface temperatures were 101.0/sup 0/F (38.3/sup 0/C), representing a rise (..delta..T) of about 43.4/sup 0/F (24.1/sup 0/C) above ambient. The frontal zone of the plume spread gradually seaward at about 0.2 kn. Its outer edge became thinner and rapidly cooled, presumably by advection and turbulent diffusion associated with currents from the reverse pumping and local changes from dissipation to the atmosphere. Along the intake shoreline, the plume was often less than 1 ft (0.3 m) thick. Most of the hot water was dissipated within several hundred feet of the intake with ..delta..Ts of about 10.0 to 15.0/sup 0/F (5.6 to 8.3/sup 0/C) above ambient. Under the influence of 15 mph southwesterly winds during the second survey, some warmed water was apparently carried beyond the outer breakwaters into Cape Cod Bay. These surveys provided real-time data indicating that the backwashing operation caused a relatively thin thermal plume, which spread rapidly from the intake out across the study area and along the seaward breakwater. Within a few hours these backwash thermal plumes were completely dissipated.

• OSTI ID: 5339388
• Journal Information: Environ. Manage.; (United States), Vol. 6:1
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
54 ENVIRONMENTAL SCIENCES
BIOLOGICAL FOULING
INHIBITION
NUCLEAR POWER PLANTS
THERMAL EFFLUENTS
DIFFUSION
FIELD TESTS
HEAT TREATMENTS
MEDIUM TEMPERATURE
OPTIMIZATION
PLUMES
WATER POLLUTION
FOULING
NUCLEAR FACILITIES
POLLUTION
POWER PLANTS
TESTING
THERMAL POWER PLANTS
220503* - Nuclear Reactor Technology- Environmental Aspects- Chemical & Thermal Effluents
520400 - Environment
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