Keeping cool under pressure

10 May 2016

Environmental issues have long been at the fore of the nuclear industry and have, over the decades, changed the way the industry operates. However concerns, whether reasonable or not, remain. But as Meredith Angwin reveals sometimes the environmental issues raised could arguably be used as a smokescreen.

The United States Nuclear Regulatory Commission is responsible for federal standards for nuclear design, operation and radiological safety. However, individual states have power and latitude for setting their own environmental standards. When a state government administration is against nuclear energy, it uses this to harass or attempt to close nuclear plants. Often, the state's attack point has something to do with water. Opponent groups also attempt to use state- level environmental power, even when the state government is in favour of the plant and values its environmental benefits.

There are several methods used by states in their attempts to close nuclear plants through water regulation. They have been known to attack the use of once-through cooling - even in cases with a condenser in the ocean. Accusations are made about fish fry entrainment and water temperature. Examples include attacks on two plants in the US, the operation of Diablo Canyon in California, Indian Point in New York, and Oyster Creek in New Jersey.

Even when cooling towers are in use, opponents can attack 'excess' temperature changes in river temperature, or excess fish entrainment. Examples include Vermont Yankee in Vermont. An opponent group frequently levels these charges against Columbia Generating Station in Washington.

Finally, claims may be made that the power plant causes various environmental issues in a coastal area. Examples include the California Coastal Commission forbidding seismic testing at Diablo Canyon and the New York Intertidal Commission claiming unspecified problems due to Indian Point.

Cooling and the fish

Diablo Canyon uses the Pacific Ocean for once-through cooling. It is a PWR, so ocean water circulates to cool the very clean secondary loop water that is used to condense turbine exhaust. The cooling water does become warmer as it cools the secondary loop's water. Moving cooling water through the final loop also entrains fish eggs and larvae at a low rate. Screens keep bigger objects, and larger fish, out of the plant.

For some in California this warming of ocean water and entrainment is seen as a real problem.

According to an article in the local Tribune newspaper when this issue was raised in 2013, 'Biologists have estimated that Diablo Canyon sucks in more than 1.5 billion fish larvae a year, most of which do not survive.' Since the same article says Diablo Canyon uses 2.5 billion gallons of seawater per day, this means the intake may affect one fish larva per approximately 500 gallons of water. There are no reports of any decline of fisheries in that area and none would be expected.

In considering this level of fish larvae mortality we might note that the average American Shad lays in the region of 30,000 eggs a year and a salmon 2,000 to 5,000 eggs. Fish eggs and larva have extremely high mortality because they're food for other fish. Fish lay thousands of eggs because most don't survive and become adult fish.

Alternatives to once-through cooling would be difficult to implement. Building cooling towers is one option discussed in the article. However, that might well require major excavations of a mountain behind Diablo Canyon.

According to plant operator PGE when the California Water Resources Control Board adopted a policy mandating that plants across the state update their once- through cooling systems, they included a way for nuclear plants to get a variance due to the importance of such clean plants to the grid. The Board carried out a study of the feasibility and cost of installing cooling towers at Diablo Canyon - estimated by PGE at $4.5 million with a significant environmental impact. The Board said if costs were seen to be 'wholly out of proportion' it would permit other forms of mitigation to be used instead. But following the study - which began in 2013 - a decision is still to be taken on what requirements to impose on the plant.

The NRC licenses for the two sister plants last until 2024 and 2025, but PG&E executives have not decided on whether to renew them. It is awaiting the results of other studies including a seismic safety review before making a decision.

Oyster Creek

Oyster Creek in New Jersey was faced with the state-mandated expense of building new cooling towers. The state determined that the plant's once-through cooling into Barnegat Bay was unacceptable. In this case the plant cut a deal with the state of New Jersey. Though the plant's NRC license extends to 2029, the state would grant the owners the right to operate the plant only until 2019 but the owners would not have to build cooling towers.

Indian Point is also constantly battling the accusation of ecological damage from its once-through cooling. The plant already uses ristroph screens that prevent even very small fish from being drawn in. However, operators have proposed adding wedge wire screens in the river that have already been approved for other facilities. Plant officials have said without contradiction that it is compliance with environmental permits that limit its discharge of heated water. Nevertheless, the state Department of Environmental Conservation has made the use of expensive cooling towers at Indian Point a major issue in state approval of relicencing.

Announcing the 2019 closure the state said: "Closure of the plant will have a significantly more beneficial environmental impact than requiring the installation of cooling towers, which, under the best case scenario would take seven or more years to be installed and, unlike plant closure, would result in significantly greater continued water withdrawals and discharges."

Cooling towers

In general if the state is against a power plant even installing expensive cooling towers will not help. Vermont Yankee had cooling towers which operated in the summer; in the winter it used river cooling. The cooling towers did not protect the plant from attack by opponents and by the state, on ecological grounds.

Around the time the NRC extended Vermont Yankee's license, the state attempted to shut the plant down with a legal maneuver in the legislature. Entergy sued the state in a case which ended with judges determining that radiation issues were the core of the legislative attempt. Entergy won the lawsuits because radiation safety is a federal issue. Authorities later turned to water quality issues as a way to gain leverage over plant operation.

The state of Vermont commissioned a study which concluded that a plume of hot water extended 25 to 50 miles downriver from Vermont Yankee. Among other things, such a plume would have meant that the heated plume survives the mixing that inevitably occurs when the Connecticut river passes through Vernon Dam, located near Vermont Yankee, and was formerly the plant's 'black start' facility. Despite the attempts of the state the plant continued to operate on the basis of its extended 2005 certificate for water discharges.
The state of Vermont sued the NRC claiming Vermont Yankee's NRC license extension was invalid because the plant did not have a valid water permit from the state at the time of the extension. Even some plant opponents were puzzled by this tactic of suing the NRC about a state certificate. This lawsuit did not conform to standard administrative law practice. New York State added its weight to the Vermont lawsuit, but the lawsuit ultimately failed with the state lost the suit.

When Vermont Yankee announced it would close it received a water permit for the last few months of its operation, in accordance with agreements that Entergy and the state made about shutdown. It should be noted in a statement by the Public Affairs specialist with US Fish and Wildlife, the Service suggested they had never said Vermont Yankee was out of compliance with its discharge permit.

Looking briefly at Columbia Generating Station in Washington, anti-nuclear groups have argued for expensive and unneeded changes to its cooling water intake system on the basis that the existing structures "may have resulted in the impingement and entrainment of fish". These groups offered no scientific evidence to support that claim while Columbia could present their measurements to show they are in full compliance with all environmental regulations. A state district court rejected the anti-nuclear groups lawsuit last year.

In other words, even having cooling towers and being in compliance with existing permits may not be enough for an American plant to avoid lawsuits and the threat of not being granted a Certificate of Public Good by the state.

Serve and protect

California has strong protections for coastal areas and coastal lands. Any changes to the Diablo Canyon cooling system would have to be approved by the California's Coastal Commission. This commission generally stands against any further building on the coast, especially in rural areas such as Diablo Canyon's location. They would likely not welcome digging into a mountain to build cooling towers.

The Coastal Commission has its own rules: it refused to allow Diablo Canyon to do offshore seismic testing because of the effect of the blasts of sound on sea mammals. This may make it hard for PGE to do the seismic surveys that may be required for relicencing.

On the East Coast, the Hudson River is still partially tidal at Indian Point. The river's tidal properties extend deep inland which, it is said, fooled explorer Henry Hudson into thinking the river was part of the long-sought Northwest Passage. Today the tidal properties of the Hudson mean the Federal Coastal Zone Management Act considers that part of the Hudson to be a coastal region.

That determination seemed to imply that Indian Point needs a review by the Coastal Management Program in order to get an extended license. However, coastal management review is not required for earlier environmental reviews. Such plants are 'grandfathered' against further review by the coastal programme. Though it would seem obvious that Indian Point fell into the 'grandfathered' category, Entergy has had to fight New York State in court, moving up through appeals courts, before that determination can be made. So far Entergy has prevailed. However, despite a unanimous - five to zero - ruling in favour of Entergy by judges in an intermediate court, the state has appealed the grandfathering case to New York's highest court, the New York State Court of Appeals meaning lawsuits are ongoing.

It's not in the water

When you get right to the crux of the matter these issues are not about the water. Billions of fish larvae make little difference to the number of fish in the river: fish lay thousands of eggs because the survival rates are so small, due to the nature of fish predators. The cooling towers at Columbia Generating Station and Vermont Yankee did not shield them from attacks by anti-nuclear groups on the basis of water quality. Entergy has to sue New York State to persuade state authorities the plant was 'grandfathered' from Coastal Requirement. Every time Entergy wins, the state appeals the ruling.

This is not about the water, ultimately; it is about the politics. In the US - particularly in states with administrations that are negative toward nuclear energy - water quality issues become a convenient reason for attacking nuclear power plants.


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