CUI Major Incident #0.1: Leakage of fuel oil into the sea

Date and Place of the Incident:

On October 11, 1990, a leakage in the pipe containing fuel oil occurred during the fuel transfer process between oil tanks at Jetty near Kawasaki, Japan.

Summary of the Incident:

1. It was observed that the piping with insulation was corroded by salt.
2. The increasing pressure of the receiving pipe from the jetty to the tank resulted in the leakage of the pipe from the corroded portion.
3. The leakage in the pipe resulted in the flow of oil into the sea.

Root Cause of the Incident:

1. Corrosion under insulation was the major cause of the accident.
2. Inadequate waterproofing of piping insulation allowed the seawater to invade the piping under insulation.
3. It was observed that the piping did not contain a corrosion protection coating. The corrosion attack resulted in adherence of up to 10 mm thick corrosion scales.

Financial Loss to Freedom Industries:

About 190 liters of fuel oil was leaked from the ruptured pipe which resulted in a substantial financial loss to G Petroleum Co., Ltd.

Environmental Impact of the Incident:

The leak resulted in contaminating the seawater causing serious environmental implications.

Fatality or injury due to the Incident:

No injury or fatality was reported due to this incident.

Non-Compliance of Safety Guidelines and Reliability Practices:

Flaws in oil facility management due to inadequate safety consciousness or information gathering are regarded to be the reason for the incident. Some of the reasons for the incident are illustrated below:

1. The company did not perform inspection checks for 10 years after the last inspection in 1980.
2. Insufficient maintenance work was performed to deal with external corrosion.
3. The pipe did not contain any undercoating to prevent corrosion under insulation. As it is extremely difficult to evade corrosion due to moisture that seeps through the insulation.
4. It was observed that the insulation was not replaced for over 30 years which resulted in deterioration of the insulation.
5. As salt corrosion progresses quickly due to various environmental conditions, a detailed inspection needs to be performed with a planned replacement of the insulation and piping.

Recommendations to Avoid Corrosion:

The incident of corrosion under insulation could have been avoided if the following precautions had been followed by G Petroleum Co., Ltd:

1. Proper maintenance of entire insulation and piping is necessary to avoid unforeseen events.
2. Leak and crack detection mechanisms must be installed in insulated structures to ensure timely actions.
3. Regular external and internal inspection of the pipes should be performed to detect and fix structural issues.
4. Suitable corrosion protection mechanisms must be installed to avoid corrosion. Adequate techniques of corrosion protection include cathodic protection, internal and external coatings, internal tank liners (with regular replacements), maintaining suitable pH of the chemical mixture, and use of high alloy steels. Some of the protection mechanisms include:
5. Application of thermal spray aluminum on steel to avoid corrosion under insulation (caused by general corrosion and stress corrosion cracking).
6. Utilizing aluminum foil wrapping over stainless steel structures to inhibit stress corrosion cracking.
7. Employing duplex alloys for enhanced corrosion resistance.

These techniques are congruent with best guidelines, industrial standards, and practices that
would aid in the prevention of corrosion under insulation.

Links to the photos/videos:

The incident report and the relevant image of the incidents can be accessed at the following web addresses:

http://www.shippai.org/fkd/en/cfen/CC1000181.html

https://minerva.jrc.ec.europa.eu/en/shorturl/minerva/mahb_bulletin_no4_final_forthewebpdf