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“More Information needed on Indian Point’s cable system” by Abby Luby

“The Nuclear Regulatory Commission wants more information from Entergy,

owner of the Indian Point nuclear power plants, about various cable systems at the

facility.

In a Safety Evaluation Report just issued, the NRC said it was concerned about

cables that were submerged under water.

“We have opened up manholes and have seen water that’s impacting these

cables,” said Neil Sheehan, spokesperson for the NRC. “We want to know how Entergy

will address moisture impacting cables especially if they are part of any of the safety

systems.”

The report was part of other informational requests needed by the NRC to renew

the operating license for Indian Point.

Nuclear power plants need expansive cable networks to operate. Cables are the

necessary infrastructure that transmits electricity to and from the plant, and are integral to

security and communications.

In February of 2007 the NRC asked Entergy to report on failures of certain

underground cables.

“We focused in on a specific issue with underground cables,” said Sheehan.

adding that all nuclear power plants in the U.S. were asked about their underground

cables.

The NRC request was prompted by two incidents in 2003 where buried cables for

key systems had failed to function; one was at the Oyster Creek nuclear facility in New

Jersey, the other at the Palisades Nuclear Plant in Michigan. At Oyster Creek buried

cables for an emergency diesel generator failed because the insulation rotted from being

submerged in water. At Palisades a buried cable failed because of premature aging.

Entergy responded to the NRC in May, 2007 citing the failure of only two buried

cables – one in 1994 and the other in 2005. One cable was 19 years old and had

“experienced catastrophic failure during operation.” The other was 30 years old whose

condition was classified as “degraded.”

More than a year later, in October 2008, NRC project manager John Boska sent a

letter to Entergy acknowledging their response, saying the issue was closed and “no

further action is requested at this time.”

Dave Lochbaum of the Union of Concerned Scientists, a Washington D.C.

watchdog group for the nuclear industry, said the NRC’s questions about underground

cables were too narrow.

“The proper question would have been whether any one has cables routed in

environments harsher than assumed in aging analyses,” said Lochbaum. “That could

include cables buried underground as well as cables routed inside buildings where

temperatures might be higher than assumed.”

Cable systems that sprawl under 239 acres where Indian Point sits is hard to quantify

said Indian Point’s on-site NRC inspector Paul Cataldo. “It’s hard to say how much cable

there is. We look at it in terms of voltage.”

High voltage transmission cables at Indian Point carry up to 138,000 volts. Some

of these are electrical feeder cables that supply electricity from the grid for the plant’s

day-to-day operation. Cables transmitting electricity to the power grid carry about

345,000 volts.

“Picture your electrical box at home,” said Cataldo. “Electricity comes in and out

of the plant with junctions and breakers that operate certain equipment like gears, pumps

and valves.”

The inability to monitor cable systems at Indian Point is a major issue with New

York State Attorney General Andrew Cuomo, who filed a 206-page contention document

last February opposing Entergy’s re-licensing application to keep the plants running for

an additional 20 years. Indian Point Unit 2 and 3 operating licenses expires in 2013 and

2015 respectively.

The attorney general attacked Entergy’s plan to check cables’ insulation once

every 10 years and for checking for water accumulation where cables are housed every

two years. According to Cuomo, Entergy’s license renewal application omitted “a copy

of the actual aging management plan for inaccessible Medium Voltage Cables.”

In their application Entergy said they will come up with a monitoring program

just before they get their license renewed. Cuomo found that unacceptable and cited agerelated

problems of degraded cables that “could threaten the capability to safely shut

down the reactor and maintain it in a safe shutdown condition” and “lead to the loss of

required plant functions.”

Sheehan said the license renewal application looks at aging management [of

cables] more broadly.

“We will be asking what Entergy is doing to protect cables for an additional 20

years.”

Entergy’s application stated that a management program monitoring certain types

of cables wasn’t required, prompting the NRC, in a May letter, to ask Entergy for an

explanation for not requiring a monitoring program. They also asked what types of cable

testing the utility company has been running.

Although Entergy spokesperson Jerry Nappi declined to comment on Entergy’s

current cable monitoring plan, NRC’s Cataldo did say that cable inspections are

performed periodically.

“The cables are in manholes and we go in and do physical checks. There are

connections to the control room where meters measure appropriate voltage and there is

surveillance of breakers.”

The issue of underground cables has consistently come up at local public

meetings for they are part of the license renewal process. Gary Shaw, a resident of Croton

said he has asked repeatedly how underground pipes, many of which house cables, are

examined.

“I have specifically asked the NRC how many linear feet of pipe are inaccessible.

What about the of 35-year old welds that have been exposed to corrosive salt water?

How are they going to determine their viability for another 20 years?””

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