Friday, July 27, 2012

More on Nuclear Energy Facilities, Summer Heat and Water Use

The following guest post was submitted by NEI Media Manager, Mitch Singer.

Perhaps it’s asking too much in today’s media climate (no pun intended), but it would’ve been nice if Ginger Zee refrained from making the flippant comment on America This Morning that cooling ponds near nuclear plants are “either getting too low or too warm for the plants to function safely.” Ginger’s wrong on a number of accounts.

Safety is paramount to the nuclear industry and all plants have contingency plans in place to adjust to extreme weather conditions and continue operating, albeit at a lower electrical power output. All nuclear power plants operate under their respective states’ water discharge permits and when the water’s ambient temperature reaches a certain level the plant’s power output must be lowered. Thus, they continue to “function safely.”

The Browns Ferry Nuclear Plant in Alabama operated by the Tennessee Valley Authority (TVA) provides a great example of how in spite of extreme heat and higher-than-normal water temperatures a nuclear plant can continue to produce electricity. TVA’s Ray Golden explained it clearly to me in a conversation earlier today:
In the summers of 2010 and 2011 TVA had to reduce electrical power output at all three Browns Ferry units up to 50 percent (approximately 500 megawatts each) to maintain downstream river temperatures within the thermal compliance limits associated with its State of Alabama water discharge permit.
Browns Ferry draws water from the Tennessee River to cool plant equipment. In the process of cooling this equipment the water gets heated. This heated water is sent to a series of seven, very large cooling towers. The cooling towers use large fans to cool the water before returning it to the river.

When the river’s upstream ambient temperature rises to 90 degrees, TVA’s water permit does not allow any additional increase in water temperature. In order to comply with this regulation, at times Browns Ferry’s power output has to be lowered.  By lowering power output we reduce the discharge temperature.

During periods of extended high river temperatures and low rainfall, the company’s environmental compliance model requires the need to take prompt action to avoid exceeding any permit limits.

TVA returns Browns Ferry and other fossil-powered generating stations to full power when temperatures and river flow conditions are adequate for full power operation without challenging river temperature permit limits.

TVA has been proactively working on a project to address the issue of summer river temperatures and the requirement to reduce Browns Ferry power output.
In the summer of 2012, TVA completed construction of a seventh cooling tower which provides additional river water cooling during the hot summer months. The seventh tower is twice the size of the existing cooling towers and uses state-of-the-art engineering and equipment to maximize cooling capability. With cooling tower #7 in operation the need to reduce Browns Ferry’s power output has been eliminated so far this summer.

TVA returns Browns Ferry and other fossil-fueled plants to full power when temperatures and river flow conditions are adequate for full power operation without challenging river temperature permit limits.
Unfortunately, there are too many reports such as this morning’s where the issue of context is never considered. The fact is that ANY power plant, including coal and natural gas, that generates electricity through steam turbines and uses cooling water to condense the steam would face similar circumstances under drought conditions.

As my colleague David Bradish pointed out in his July 11 blog post, the National Oceanic and Atmospheric Administration reported that the month of June experienced “170 all-time high temperature records being broken or tied throughout the country.” Yet, America’s nuclear plants operated at an average of 90 percent capacity, as they have done so for most of the past decade. That’s a record of consistency that would make baseball great Cal Ripken take notice.

The Brown's Ferry nuclear energy facility in Alabama. Pic courtesy of TVA.

3 comments:

jim said...

I really wouldn't let Ginger Zee's specious quip slide unchallenged and uncorrected. Every off-hand media remark like that sets back the hard valiant progress of public nuclear energy education programs months and sows instant FUD. ABC is just going to sweep my email aside, so it'd help of there was a concerted effort to admonish Lee and ABC on this, especially since we all know how the media is going to commemorate the virtues and record of nuclear energy this coming Aug 6th!

James Greenidge
Queens NY

Anonymous said...

I dread the prospect of this annual rite of self-flagellation we indulge in every August 6th. The nuclear industry has nothing to apologize for or made to suffer any guilt trips over. We weren't even around then. If the nuclear industry is going to be blamed for Hiroshima and Nagasaki, then so should the wind power industry, since those weapons were delivered with propeller-driven aircraft, and I think there is more linkage between prop planes and windmills than there is between power reactors and bombs. If they are going to play those games, I say we throw it right back in their (ugly) faces.

SteveK9 said...

If heat waves like this continue, and become common, I suspect some of those temperature limits are going to be raised. Either put water back in the stream 2 C higher than before, or go without air conditioning in 105 F temperature --- I think I know how most people will vote.