Model olarak alınan bir kimyasal tanker gemisine SEVESO II direktifinin uygulanması
Application of SEVESO II directive received as a model chemical tanker vessel
Yazar: TAYLAN GÜLER
Danışman: DR. ÖĞR. ÜYESİ ELİF BAL BEŞİKÇİ
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Deniz Ulaştırma Mühendisliği Ana Bilim Dalı / Deniz Ulaştırma Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2019
Konu: Denizcilik = Marine

Özet:
Günümüzde ülkelerin işletim sahasında kullanılan kimyasal ürün ve türevlerinin sayısı her geçen gün artmaktadır. Ülkelerin veya işletmelerin ihtiyaç duydukları kimyasal ürünlerin bir yerden başka bir yere transfer edilmesi veya nakliyesinde kullanılan araçlardan bir tanesi de kimyasal tanker gemilerdir. Ülkelerin ihtiyaçları ile birlikte taleplerinin artması, orantısal olarak kimyasal tanker gemilerinin sayılarının artmasına da neden olmuştur. Kimyasal tanker gemileri, bu talep edilen kimyasal ürünleri sıvı halinde tanklarında taşımaktadırlar. Bu taşıma işlemleri öncesinde ve sonrasında birçok operasyon yapılarak bir ülkeden diğer bir ülkeye transfer edilmektedir. Yapılan işlemlerden bazıları şunlardır; yükleme operasyonu, tahliye operasyonu, tank yıkama operasyonu, inertleme operasyonu vb. Bu yapılan operasyonlar gemi bünyesindeki personel ve mevcut ekipmanlar ile yapılarak proses devam etmektedir. 
Kimyasal ürünler çeşit çeşit olmakla beraber özellikleri bakımdan farklılık gösterebilmektedir. Bu maddelerin yanlış istiflenmesi veya yanlış operasyonlarının yapılması insan ve doğaya karşı büyük kaza ve tehlikelerin oluşmasına sebebiyet vermektedir. Bu maddelerin depolanması, kullanımı, üretimi veya bertarafı sırasında oluşacak bir aksaklık sonucu meydana gelebilecek bir patlama, yangın veya sızıntı, ağır tahribata yol açabilir. Son zamanlarda gemi ve kimyasal ürünlerindeki artış da kazaların artmasında etken oluşturmuştur. Gemilerde meydana gelebilecek kazaları minimize etmek için bir takım faaliyet ve bunları azaltmak için uygulanan bir takım uluslararası kurallar mevcuttur. Ancak bunlar olabilecek risklerin hesaplanmasına ya da tespit edilmesine yönelik değil önlem amaçlı personel ve işletmelere sunulmuştur. İşletmelerde ortaya konan kural ve yönetmelikleri gemilerine adapte ederek direktif veya bilgilendirme şeklinde Uluslararası Güvenli Yönetim sistemleri içerisinde gemi personeline sunmaktadırlar. Bu prosesin yürütülmesi gemi personeline yani insan eline bırakıldığı için birçok kaza da meydana gelmektedir. Kara sahasında bulunan kimyasal tesis veya terminallerde de kimyasal tanker gemisinin yapmış olduğu operasyonlara benzer prosesler bulunmaktadır. Ancak  meydana gelen birçok büyük kazalardan sonra kara tesisleri direktifler ile bunları minimize etmeye çalışmaktadırlar. Kara sahasında kullanılan en önemli direktiflerden bir tanesi de SEVESO direktifidir. SEVESO I sonrasında meydana gelen büyük endüstriyel kazalar SEVESO II'in geliştirilmesini zorunlu kılmış ve sonrasında SEVESO II olarak adlandırılan Avrupa Birliği Konsey Direktifi oluşturulmuştur. Türkiye, hem Avrupa Birliği üyelik sürecinin bir gerekliliği olarak hem de olası büyük kazaların önlenmesi için Seveso II Direktifi'ni, 'Büyük Endüstriyel Kazaların Kontrolü Hakkında Yönetmelik' ile iç hukuka aktarmıştır. Kara tesislerinde ve terminallerde direktifin getirmiş olduğu uygulamalar zorunlu hale getirilmiştir.
SEVESO direktifi şu anda  gemilerde uygulanmaya başlanmamıştır. Ancak benzer processlerin olduğu kimyasal terminal veya tesislerde uygunlanmaktadır. Bu tez ile model olarak alınan Kimyasal tanker gemisi üzerinde Seveso II direktifinin getirmiş olduğu metodoloji ve analizler  , model olarak seçilen kimsayal tanker gemisinde  bir senaryo belilenererek uygulanmıştır. Senaryoda çıkan risk eşiği SEVESO II kritirleri ile değerlendirilirek uygunluğu kontrol edilmiştir.

Anahtar Kelime : SEVESO II ,  Kantitatif Risk Değerlendirnmesi , Kimyasal Tanker Gemisi  ,Kimyasal Tanker Operasyonları, ARAMIS , MIMAH , MIRAS.

Abstract:
Presently, the number of chemical products and derivatives that has been used in processing grounds of countries are escalating. Chemical tankers are one of the main tools for transferring these chemical products that are needed by countries and companies. Along with the increasing needs of countries and consequent rising in demands, total number of tankers that are designed to carry these products are in an increasing trend. Chemical tankers carry products by storing them into their tanks. Before and after each carrying operation, there are many operations that should be carried out. Some processes are; loading, discharging, tank cleaning and inerting etc. All of these operations are conducted by the personnel and the equipment on board a vessel and the process goes on. 
There are various types of chemical products and they all have different specifications. Improper stowing or misconducting of the operation may result in a disaster for both human and the environment. A fault in stowing, using, producing and disposing these substances may cause an explosion, fire and leakage related damages. Lately, insufficient trainings of ship's crew about chemical substances and the increasing numbers of  chemical product types are the main reasons for escalating numbers of accidents. 
To minimise these probable accidents in ships, there are some applications and international regulations. Nevertheless, these are not designed for detection and calculation of risks but rather presented as precautional purposes to related staff and companies. Companies adapt these instructions to their vessels and presents as a manual or information booklet for their staff in accordance with International Safety Management. Performing of these processess and procedures are carried out by ship's personnel so there are many accidents stems from the human factor. Chemical facilities and terminals on shore side are also have  similar processes like chemical tankers. Shore terminals are trying to minimise these accidents with adopted directives and one of the main directives is the SEVESO. 
Industrial accidents that had occured after the implementation of SEVESO I  had entailed improvements to SEVESO I and consequently 96/82/EC Counsil Directive which is named as SEVESO II is introduced. Turkey has transferred SEVESO II to its domestic law within the scoep of both United Nation membership procedures and to prevent disasters with a name of "Regulations for Controlling  Industrial Accidents". Regulations that are obliged by the directive became compulsory for shore facilities and terminals.
SEVESO II is the most important item for protection of the environment and people  among all UN directives. This directive is in use by  industries that use highly hazardous substances. Directors of these industrial corporations must show that they have an administrative system policies that include both hardware and software measurements to prevent fatal accidents. Although it is not an easy task to reveal naturally, These policies should be able to decrease risk levels of  not only the accidents with high probability and low impact but also the accidents with low probability but  severe impacts. 
In United Nations, "Defining  Probable Accident Scenarios" is a significant issue in risk assessment in the scope of SEVESO II Directive. Existence of uncertanities about determining probable accident scenarios and to pinpoint where to begin risk assessments initially, had led to the creation of ARAMIS methodology which is developed by European Union Countries to overcome these uncertanities and to guide them. 
The main aim of ARAMIS project is to unify the strengths of common risk assessment methods that are currently being used by European Union countries and to create an integrated model. ARAMIS consists of following stages:
• Methodology for Identification of major accident hazards (MIMAH)
• Identification of safety bariers and performance assessment
• Assessment of safety management efficiency for barier reliability
• Methodology for Identification of reference accident scenarios (MIRAS)
• Assessment of the impacts of reference scenarios
With this thesis, stages in ARAMIS methodology which forms the content of ARAMIS directive have been applied on a specific chemical tanker and the conformityof  risk threshold which is agreed by SEVESO II directive is controlled according to the present equipment. 
In the introduction part, the purpose of the SEVESO II, definition of ARAMIS project, accidents in chemical tankers and facilities and information about the model chemical tanker have been given. After the introduction part which is mainly focused to highlight the assessment stages of ARAMIS methodology, chemical tanker operations are explained and present equipments that are being used are defined. Scenarios have been pre-selected for the application of SEVESO II directive. Risk assessments of the operations that have been carried out in chemical tankers are assessed by HAZOP study and the most probable accident scenario is determined. Information about the chemical product which is used in the scenario and the risk of the operations that are conducted onboard the ship and furthermore, the precautions that should be taken, are given. Additionally, specifications of the model chemical tanker and current equipments are presented. 
Methodologies and analysis in the thesis have been conducted as a part of SEVESO II directive  within the scope of ARAMIS methodology and divided into 3 stages. These are: 
• Survey study
• Identification and assessment of  fatal accident hazards and  applied methodology
• Data resources
In the application process of ARAMIS methodology, it is asked to be weighted that the safety management efficiency index and safety culture of the employees and companies. Each company's approach is the same. Chemical tanker companies and employees' safety culture and safety management efficiency index is calculated via a questionnaire survey. Results are used in the determination of the barrier's error ratio  in bow-tie analysis. Barrier types and equipments and the data structure that are used in survey papers and in the thesis are defined. 
During the identification of significant accident hazard and the application process of SEVESO II, risk analysis method that is used in MIMAH methodology is  Quantitative Risk Assessment (QRA). The purpose is to analyse the risk created by a  company for its surroundings by using risk contour maps and F-N curves  that consist of individual and social risks. However, as the aim in the thesis is to identify whether the risk frequency is above or under the SEVESO II threshold, risk contours and F-N curves are not given but briefly mentioned. In accordance with ARAMIS methodology, these steps listed below are used in data gathering for the model chemical tanker:
• Analysis of hazardous chemical substances in the chemical tanker have been made
• Potential risky equipments are identified. In this process, ARAMIS-VADE MECUM and Dow Fire and Explosion indexes have been utilised.   
• HAZOP , LOPA , Fault tree and bow-tie analysis were used for identification of hazards and basis for risk threshold have been created.
• In order to define and select the accident scenario where SEVESO II directive is applied, reference has been made by using MIRAS methodology.
• For quantitative risk analysis, information about major accidents, selected root causes and loss of integrity are defined in the selection process of scenarios.
• After forementioned processes, how calculations are made and risk thresholds are defined and calculated respectively. 
• Results of risk thresholds that are obtained from scenarios have been evaluated by ALARP methodology according to their eligibility to SEVESO II. 
To identify failure rates of equipments which are used in scenarios and error rates and/or probability of errors by crew members, Literature Equipment Reliability Data and Protective Systems Failure Rates Sources and Technique to Estimate Operator's Errors (TESEO) methods are used and data obtained. 
A reference accident scenario for a model chemical tanker is addressed and results are obtained by bow-tie method in the scope of ARAMIS methodology, Obtained risk is 7,826 x10-3 incident/year and this result is  about 78 times higher than the accident threshold introduced in SEVESO II which is 1x10-4. The result clearly indicates that the model chemical tanker is highly dangerous and has a significant risk potential. 

Keywords: SEVESO II ,  Quantitive Risk Assesment , Chemical Tanker, Chemical Tanker Operations, ARAMIS , MIMAH , MIRAS.