Tag Archives: Massachusetts

Investigation findings: Corrosion at Michigan nuclear plant due to stainless steel components

A recent investigation by the Nuclear Regulatory Commission found that the failure of a water pump due to the corrosion of certain kinds of stainless steel components caused an August shutdown of the Palisades nuclear power plant in Covert.

In a news release from his office,Congressman Edward J. Markey, D-Mass., senior member of the House Energy and Commerce Committee, questioned why a substandard steel is still being used for certain plant components.

Here’s what it says:

Despite scientific findings and industry experience reporting its vulnerability to cracks and corrosion, the types of stainless steel –known as 410SS and 416SS – continues to be used in water pumps used to provide cooling water to critical safety-related equipment such as component cooling water, diesel generators, and containment vessel air coolers for nuclear power plants throughout the U.S.

Markey sent a letter querying the NRC about the vulnerability of these metals to corrosion cracking and their continued use despite two decades of failures in nuclear power plants, according to the news release.

Here’s more from the release:

Despite NRC alerting licensees about issues with these pumps, failures continue and licensees have not been required to take any action or even report back to the NRC regarding what they are doing to identify, mitigate or prevent corrosion cracking that could cause component failures.

“They say there was never a good knife made of bad steel. Similarly, you can’t have a safe nuclear reactor made of bad steel,” Markey said. “I am concerned that U.S. nuclear power plants using components made from 410 and 416 steel may be subject to failures of critical safety equipment and at risk of shutdown. NRC must ensure that it requires licensees to take steps to identify and mitigate any corrosion of its components in order to demonstrate that they will perform satisfactorily in service, especially for critical safety-related operations.”

In the letter, Markey asks the NRC to respond to questions that include:

• Which U.S. nuclear power plants currently use 410SS and 416SS components and what are the known uses of 410SS and 416SS?

• Will the NRC undertake a review of 410SS and 416SS steels to determine if additional periodic inspections and mitigation efforts are warranted?

• What regulatory actions will be undertaken in order to assess, require licensee reporting and inspection of, and address problems involved in 410SS and 416SS components?

In March, Congressman Fred Upton pledged support of the nation’s nuclear plants, three of which — Palisades Power Plant in Van Buren County and two at the Cook Nuclear Plant in Berrien County— are in his district, which covers southwestern Michigan.

Upton is chairman of the House Committee on Energy and Commerce.

SOURCE: http://www.mlive.com/news/kalamazoo/index.ssf/2011/12/bum_steel_creates_dangers_at_p.html

Bridge inspection in Bristol, Massachusetts revealed ‘severe’ corrosion

Bristol, MA — The inspection that led the state to drop the Brightman Street Bridge weight limit to 3 tons noted “severe” deficiencies in multiple parts of the bridge, including some that were said to require action as soon as possible.

Five months after the inspection, the Department of Transportation hasn’t made the repairs because the bridge is expected to be replaced by late summer by the Veterans Memorial Bridge, a DOT spokesman said. The weight limit was lowered instead.

Corrosion in some locations was also so bad that parts of some beams had withered away entirely. The report, from an inspection in February, also described “wavy deformations” on some bridge supports and “severe cracking” — including some fissures longer than two feet — to some steel girders and beams.

In addition, 170 cracked steel bars were found on the bridge deck, and corrosion holes of up to 1.5 inches in steel grid primary bars, the inspection said.

The condition of multiple supports was marked “severe,” a 3 on a 0-to-9 scale, indicating deterioration, or cracking steel or concrete that made “local failures… possible.”

Brightman street bridge
Advanced deterioration throughout the length of a sidewalk stringer on the Brightman Street Bridge.

The DOT said in a statement that safety remains its highest priority.

“Mass DOT carefully monitors and inspects all bridges on a routine basis,” spokesman Michael Verseckes said. “Through a combination of strategic repairs and the reduction in the weight limit, we have taken the necessary steps to ensure the Brightman Street Bridge is safe for travel for ordinary motor vehicles as well as ambulances. We look forward to the opening of the new Veterans Memorial Bridge in the near future.”

The inspection focused on five parts of the bridge — the deck and various support beams and girders — that had also previously been noted as being in “severe” condition. The only worse conditions on the rating guide are “critical,” in which the bridge may need to be closed until repairs are made, “imminent failure,” in which the bridge is closed but could be repaired, and “failed,” when a bridge is beyond repair.

Photos included in the report show cracks to the steel bars in the middle of the bridge span, major deterioration to support beams below the sidewalk, cracked welds, and corrosion in numerous other areas.

A cover sheet to the inspection report dated May 24 suggested the weight limit for vehicles be lowered from 9 tons to 3 until the recommended repairs were made or until the bridge was taken out of service. The weight limit was reduced about a month later.

Since then, despite police presence leading to the bridge, vehicles that well exceed the limit have been seen passing over the bridge anyway, including an 18-wheeler soon after the limit was changed. Ambulances, which can weigh up to 9 tons, were allowed an exception as long as they’re driven in the middle of the two travel lanes. One beam below the bridge deck, called a stringer beam, was repaired last weekend.

The Veterans Memorial Bridge is planned to open in August or September, but no specific dates have been given.

SOURCE: http://www.heraldnews.com/archive/x1009566775/Brightman-Street-Bridge-inspection-revealed-severe-deficiencies#ixzz1Spm8Dl37