1. When risk assessment for thermal power plant (TPP) is needed?
According to Article 15, QCVN 11:2012/BCT, the thermal power activities of which the quantitative risk assessment is compulsory, including:
- The thermal power activities include the construction, installation, operation, renovation, and dismantlement of coal thermal power stations and gas thermal power stations of which the output reaches at least 300 MW;
- The construction, installation, operation, renovation, and dismantlement of coal thermal power stations and gas thermal power stations of which the output is lower than 300 MW, but the capacity of the oil storage exceeds 10,000 m3.
Objectives of the risk assessment report include:
- Identify all hazards can harm people, environment, asset by qualitative risk assessment workshop;
- Consequence modeling to determine impact dimension of incidents;
- Calculate risk based on frequency analysis and consequence;
- Recommend to reduce risk to ALARP level;
- Demonstrate that risk values are in acceptable ranges for obtaining approval from the Ministry of Industry and Trade or the Department of Industry and Trade for risk assessment report.
3. Legal requirements
- Law No. 84/2015/QH13 on occupational safety and hygiene;
- Circular No 07/2016/TT-BLĐTBXH, regulation on occupational health and safety in producing and trading facilities;
- Law No. 06/2007/QH12 on chemicals;
- The law No. 40/2013/QH13 amending and adding a number of articles of the law on fire prevention and fighting and related law documents;
- Circular 40/2018/TT-BCT dated October 30, 2018 prescribing formulation and contents of documents on management of safety for petroleum operations;
- Circular No. 50/2012/TT-BCT of December 28, 2012, promulgating the national technical regulation on risk acceptance criteria used for quantitative risk assessment (QRA) of petroleum, oil and petrol, chemical, thermal power activities;
- Circular No. 43/2010/TT-BCT dated December 29, 2010 regulation on safety management in industry and trade;
- Document 42/EVN-AT dated January 04, 2018 on the execution of risk assessment and management.
4. Contents of the Risk assessment report
Risk assessment report will be followed on circular 40/2018/TT-BCT. The content includes:
- Chapter 1: Introduction
- Chapter 2: Methodology
- Chapter 3: Risk acceptance criteria
- Chapter 4: Hazard identification
- Chapter 5: Frequency analysis
- Chapter 6: Consequence modeling
- Chapter 7: Risk calculations
- Chapter 8: Conclusion and recommendations
5 How is a good quality risk assessment report for the TPP developed?
In order to develop a good quality risk assessment report, besides a safe and efficient site survey for obtaining all information about TPP, the following notes should be considered:
- For qualitative risk assessment, all hazards in areas and from operational and maintenance activities shall be identified. Safeguards including prevention and mitigation will be also assessed. Proposed recommendations will be considered by TPP management for reducing risk. HAZID workshop with the participation of TPP staff (HSE, operation, maintenance, worker, etc.) will meet the above requirement for qualitative risk assessment. In the workshop, a major accident event (MAE) will be described by Bowtie XP software that illustrates the Bowtie diagram. Bowtie is the method to identify the threats and consequences of the initial event and establish barriers to reduce risks from both sides, before the incident (prevention) and after the incident (mitigation).
- Quantitative risk assessment includes:
- Failure frequencies will be referred to as reputable references, e.g. OGP, HSE UK, OREDA, CMPT, WOAD, etc.
- Modeling data will be referred to as TPP operational parameters. During the collection process, incorrect information can be incorrect. The consultant will submit an assumption register to the client for a review of the consistent methodology and data used for quantitative risk assessment.
EVN group’s document No.42/EVN-AT dated 04/01/2018 regulated “Risk assessment is compulsory for electric operations including production, transmission and distribution” in which, qualitative risk assessment was instructed in detail. Simultaneously, “EVN requires subsidiaries to research and implement risk management and assessment in accordance with the provisions of the legal documents to prevent and mitigate labor accidents and occupational diseases”. QCVN 11:2012 only regulated quantitative risk assessment for thermal power plants with a power of 300 MW or higher and quantitative risk assessment must be conducted at the design phase. In operation, QRA will be assessed periodically every 5 years without modification. With the importance of qualitative risk assessment mentioned above, all thermal power plants with the power of lower than 300 MW, need to be qualitative risk assessed to reduce risk as well as comply with the requirements of EVN.