Wednesday, October 02, 2013

Why the Electric Sector Needs Flexibility to Comply With 316(b), Not Just Cooling Towers

The following post was submitted by William Skaff, NEI's Director of Policy Development.

The Sierra Club and Riverkeeper report, Treading Water, claims that the 316(b) rule governing cooling water intake structures of existing facilities should impose a national standard that requires the installation of cooling towers everywhere, preventing state environmental agencies from determining the best technology available at their sites for minimizing environmental impact.

As the U.S. National Renewable Energy Laboratory reports, “[C]ooling tower technologies consume at least twice as much water as once-through cooling technologies” [emphasis added]. 1 That is, cooling towers consume twice as much of aquatic life habitat as once through cooling systems. Given that climate change modeling indicates freshwater constraints, why would we want a nation of cooling towers? How can doubling water consumption possibly protect fish in a water-constrained future?

All cooling systems, including cooling towers, have advantages and disadvantages. Thus, the best approach is site-specific—adopting the cooling system that best preserves a given local ecology. There is a total of 3,153 species of fish in the fresh and salt waters of the United States. 2 Every water body has a different mix and population of these species, and each species differs in susceptibility to impingement and entrainment, to potential impingement and entrainment mortality, and in behavioral responses to various technologies developed to prevent these occurrences. Thus, the most effective deployment of cooling system impingement and entrainment mitigation technologies will be according to site-specific analysis.

According to the U.S. Environmental Protection Agency, “Most facilities potentially regulated under the proposed Existing Facilities rule have intake technologies already in place.” 3 In fact, EPA did not select closed-cycle cooling as the “technology basis” for impingement mitigation for existing units because “modified traveling screens with a fish return system and closed-cycle cooling are comparable in impingement mortality performance.” 4 Moreover, once-through cooling systems are not outdated: the United Kingdom’s Environment Agency recommends that new nuclear plants be built on coastal sites with once-through cooling precisely because of their environmental attributes in view of climate change. 5 In fact, site-specific research conducted at power plant sites across the country submitted to state authorities as a requirement of their NPDES permit indicates that once-through cooling systems have no adverse environmental impact to aquatic life at the population level.

In conclusion, the more environmentally responsible approach to the 316(b) rule at existing facilities is to provide flexibility in choice of fish protection technology according to the ecology of the specific site, considering environmental, social, and economic factors. And who would know these sites the best but the state environmental agency?

1 National Renewable Energy Laboratory (Jordan Macknick, et al.), A Review of Operational Water Consumption and Withdrawal Factors for Electricity Generating Technologies, NREL/TP-6A20-50900, March 2011, p. 6.
2 FishBase at (accessed June 27, 2011).
3 Technical Development Document for the Proposed Section 316(b) Phase II Existing Facilities Rule, EPA-821-R-11-001, March 28, 2011, p. 4-14.
4 76 Fed. Reg. at 22,205.
5 United Kingdom, Environment Agency, Cooling Water Options for the New Generation of Nuclear Power Stations in the UK, June 2010, pp, 181, 185.


Paul said...

It looks to me like a chess move: force all thermal power plants to use cooling towers, then claim that thermal power plants with cooling towers are using (evaporating) too much water that could be used for potable water, irrigation, or habitat.

Dan Williamson said...

Just another thinly-veiled gambit to drive up the cost of nuclear. And if the dirt-burners take a little collateral damage, so be it.