OREANDA-NEWS. September 09, 2014. We sincerely regret the great trouble, anxiety, and inconvenience caused to the people of the local community and those concerned by the accident at the coal storage tower of No. 1 Coke Oven on the premise of Nagoya Works of Nippon Steel & Sumitomo Metal Corporation (“NSSMC”) on Wednesday, September 3, 2014. We also express our deepest regret and compassion to all those who were injured.

1. How the accident occurred
-    At about 10:30 a.m. on September 3, a rise in the temperature and a rise in the concentration of carbon mono-oxide (CO) were detected inside the coal storage tower of No. 1 Coke Oven on the premise of Nagoya Works. (The coal storage tower is to temporarily store the coal, the raw material for coke. The coal is transported from the ground and is fed to the coke oven.)

-    The operators went to check the site and found that white smoke came out of the hopper, a part of the coke storage tower which stores low moisture coal.

-    At about 11:30 a.m., the public and in-house fire brigades checked the inside of the tower and confirmed that only the smoke and no fire were generated.

-    As the smoke was filled within the tower, the direct watering to the hopper was not conducted. Instead, the fuming coal was removed out of the hopper. During this process, the abnormal combustion broke out.

2. What caused the accident
As of now, our understanding of the cause of the accident is as follows: low moisture coal was retained in the hopper of the coal storage tower of No. 1 Coke Oven for a long time and part of the coal generated heat; then, the heat generation of the coal produced flammable gas; furthermore, when the coal was removed out of the hopper, the air flew into the hopper, causing the abnormal combustion to break out.

In close coordination with the relevant authorities, we will continue to investigate the cause of the accident, mainly by the urgently-established Coke Accident Committee (see below).

3. What we organized for dealing with the accident
Since September 3, the Emergency Control Headquarters, headed by the President and with the objective of emergency response to the accident, has been convened every day for the purpose of enabling the initiative by the top management and the quick sharing of relevant information.

In addition, the Coke Accident Committee was launched on Thursday, September 4 to facilitate to take rapid and needed measures by the whole company. This Committee plans to invite some outside experts and is currently studying and selecting candidates.

4. What we do from here
Nagoya Works has five coke ovens (including No. 3 Coke Oven which is currently idle). After the accident occurred in No. 1 Coke Oven, No. 2, No. 4, and No. 5 Coke Ovens were suspended in order to ensure safety.

Based on our current judgment that the accident was triggered by the low moisture coal which was stored for a long time (see above), we have decided to stop using the low moisture coal and switch to the high moisture coal which would not generate heat even it were stored for a long time in No. 2 and No.4 Coke Ovens, the similar type to No. 1 Coke Oven. (No. 5 Coke Oven has a different equipment construction which prevents the air from flowing in.)

We explained the above decision to the regulatory and administrative authorities, which then acknowledged resumption of the operation of No. 2, No. 4, and No. 5 Coke Ovens which did not have the accident.

We will carefully confirm the safety of those three coke ovens and work on restarting them from today or later. At the same time, we will promptly start briefing sessions to the people of the local community. Subsequently, we will work on restarting other facilities including blast furnaces and steelmaking facilities. 

No. 1 Coke Oven where the accident occurred will remain stopped. We will thoroughly investigate the cause of the accident and take measures to prevent similar accidents.

5. How we recognize and deal with operational management issues behind the series of accidents
  
We will continue to keep reviewing the operational management issues of Nagoya Works and are determined to make utmost efforts to address those issues. The work process, organization structure, and training and fostering of employees form the foundation of the management of steel works. We will thoroughly review all those critical elements and take measures needed from short-term and long-term perspectives. The whole-company efforts will be made to review specific issues such as work allocation of the operational division and the maintenance division of the works, operational coordination between manufacturing floors and staff divisions, allocation and development of electrical and energy engineers, and the risk control structure.