Welcome to the early November edition of the Corrosionpedia News Roundup. For this installment, we discuss two instances of corrosion in the state of California. We also highlight exciting corrosion prevention innovations involving copper and concrete structures. A change in EPA regulations for corrosion prevention in drinking water systems is also spotlighted.
New Copper Corrosion Prevention Method Developed
Scientists have recently discovered a new way to protect copper from corrosion. A team at the Indian Institute of Technology in Varnasi, India has developed the new method, known as floating film transfer. Floating film transfer involves forming a film of a substance known as squarine on top of a container of water. This floating film is then placed onto the copper and dried. Floating film transfer differs from other methods of copper corrosion prevention because it is potentially more feasible and more effective at protecting a copper substrate, especially in an environment where pH levels are low.
Bacteria Used to Reduce Concrete Structure Corrosion
Japenese researchers have found an effective method to slow the rate of corrosion of concrete reinforcement materials using bacteria. Steel bars are frequently used to improve the mechanical properties of concrete structures; however, steel is subject to rusting. Over time, as the reinforcing steel rebar oxidizes, concrete structures become more susceptible to failure.
To prevent the oxidation of the steel bars, a team of scientists at Japan’s Ehime University have added a particularly resilient bacteria, known as Bacillus subtilis natto, to cement mixtures during their experiments. This bacteria consumes oxygen, thus reducing the amount available to corrode the steel reinforcing bars. The bacteria also encourage calcium carbonate formation, which can create a self-healing mechanism for damaged concrete.
EPA Offers Alterations to Lead and Copper Rule
The United States Environmental Protection Agency (EPA) has suggested changes to the Lead and Copper Rule, which sets the standard in the US for lead and copper levels in drinking water. One of the revisions suggested is for corrosion treatment systems. Under the current version of the Lead and Copper Rule, corrosion treatment systems must prevent lead levels from being above 15 particles per billion and copper levels from being above 1.3 particles per million. With the new revision, lead levels would be required to be under 10 particles per billion. This could require a substantial restructuring of some corrosion prevention systems that do not currently meet the 10 ppb lead level requirement.
New Well Plug Product Successfully Implemented
A new isolation cap developed by Universal Subsea Incorporated was recently installed at a job site for the first time. The plug, known as the Defender, is a subsea well plug. For its first implementation, it was sent to the Green Canyon oil field area in the Gulf of Mexico where it was used to plug an abandoned well. The isolation cap offers several product advantages, such as a complete mandrel isolation and a low-pressure design. For the installation, the isolation cap was used in conjunction with Defender Stasis equipment preservation fluid, which is an environmentally friendly substance that helps prevent corrosion.
Corrosion a Concern for Temporary Nuclear Storage
The California Coastal Commission and Southern California Edison are under scrutiny as they begin to move nuclear fuel from an old nuclear plant in San Onofre, California. The plant began operation in 1968 and closed in 2012 due to leaks and concerns about plant integrity. As part of the decommissioning, the nuclear fuel must be moved offsite. It is first being moved to a nearby interim location before being sent to its eventual permanent storage location. However, environmentalists are concerned that the canisters being used to contain spent nuclear materials are inadequate to make the journey from the interim storage site to the permanent storage site. In addition to wall thickness loss, corrosion resistance is a chief concern of this claim. Southern California Edison stated that the storage practices are currently meeting all regulations.
Corrosion Risks Close Elementary School
A school in Indio, California has cancelled classes due to structural corrosion. The primary concern is rusted steel support columns, which were discovered by a worker making improvements to the school. Currently, no one except authorized personnel are allowed to enter the school until it is deemed safe again. Plans are currently being developed to repair or replace the corroded supports.