«Item 7b Severe Accidents Related Issues Preliminary Monitoring Report Report to the Federal Ministry of Agriculture, Forestry, Environment and Water ...»
The SAGs should provide instructions to determine the availability of equipment, positive and negative aspects of the strategy, limitations on the use of this strategy, impact of not implementing the strategy, and plant response after implementing the strategy (short-term and long-term). More than one SAG may be evaluated at a time, but the implementation of SAG strategies should follow priorities specified in the DFC.
The SCGs are similar to SAGs except that they do not contain evaluation of negative impacts. The SCG is not terminated before the relevant SCST parameter has change status (as specified in the SCST setpoints).
The SAEG-1 provides instructions for TSC long-term monitoring. These guidelines are used once any strategy is implemented (in addition to DFC and SCST monitoring). SAEG-1 instructs to monitor the parameters associated with active strategies. SAEG-2 provides instructions for SAMG termination. It is implemented once a controlled stable state is reached. Concerns to be addressed when leaving structured SAMG guidance are identified using this procedure.
It should be noted that the structure and format of SAMGs should follow general principles on human factor. Preparing appropriate instructions on writing the SAMGs (procedure writers’ guidelines) at the beginning of the SAMG development project is considered a good practice.
Current plant status The structure and format of SAMGs at Temelín were described during the Prague workshop [Dessars 03, Sỷkora 03 a]. They are consistent with the recommendations provided in the generic WOG guidelines [WOG 01] (as discussed above).
Evaluation The structure and format of SAMGs at Temelín can be considered to reflect the current stateof-the-art practice since the authors were using all available WOG support.
72 ETE Road Map - Preliminary Monitoring Report – Item 7b: Severe Accidents Related Issues
3.6 SAMGs Development and Implementation The SAM strategies, which were selected, (based on the process discussed in Section 3.2) need to be implemented at the plant in procedural form (SAMGs). The overall scope of the
plant specific implementation consists of several parts:
- Definition of SAMG setpoints based on plant specific parameters;
- Development of plant specific computational aids;
- Documentation of plant specific equipment capabilities, flow path alignments and support conditions (for the attachments to the SAGs and SCGs);
- Assessment of instrumentation ranges and capabilities to define the preferred and alternate methods for obtaining quantitative information for the key plant parameters in Diagnostic Flow Chart (DFC) and the Severe Challenge Status Tree (SCST) used in the TSC;
- Integration of plant specific IPE/PSA insights into the generic SAMG;
- Introducing plant specific EOP changes based on ERG revisions for transitions to the SAMG;
- Preparation of plant specific control room SACRGs; and
- Preparation of plant specific TSC guidance (DFC and SCST, SAGs, and SCGs).
The overall development of a plant specific severe accident management program should also include several other tasks which are not directly related to the preparation of procedures, but which would be required to enhance the usability of the guidance on site. These tasks are related to the emergency preparedness and include development of a program for training the utility emergency response staff and management in the usage of the SAMG, review of and co-ordination with the existing overall ERP, and validation of SAMGs against the site E-Plan.
Correctness and quality of the plant specific SAMG package needs to be ensured by following a well defined and strictly controlled process during the development of the guidelines and by provisions for proper maintenance of the related plant documents. The following subsections address relevant aspects of SAMG implementation process.
Sections 3.6.1 – 3.6.4 focus on the relevant quality aspects relating to SAMGs development.
1 discusses basic QA rules that should be covered in the QA programme. The role of internal and external reviews at different stages of the development is addressed in Section 3.6.
2. Validation tests that should be conducted using plant specific simulator are covered in Section 3.6.3. Provisions for SAMG revision and update are addressed in Section 3.6.4. Sections 3.6.5 – 3.6.7 are devoted to staff proficiency aspects, covering the SAMrelated staffing and staff qualifications (Section 3.6.5), training process (Section 3.6.6), and feedback from training (Section 3.6.7).
3.6.1 QA during SAMGs Development
VLI No. VLI title / description 7.1.1 What administrative arrangements have been introduced at the plant to control the process of SAMG development and implementation?
7.1.2 Has the SAMG writer team been established from plant personnel or outside sources?
What was the role of plant staff in the preparation and review of the SAMG package?
7.1.3 What was the expertise and depth of knowledge of the staff involved?
ETE Road Map - Preliminary Monitoring Report – Item 7b: Severe Accidents Related Issues 73 State-of-the-art requirements and practices QA applied during the development and implementation of the SAMG package should be
conducted in accordance to existing QA requirements related to document control. The following basic QA rules should be followed:
- Documents should be controlled in accordance to management/administrative procedures (as defined in the overall QA program in place at the plant),
- Staff responsible for analyses should be qualified for the job and their qualification should be documented,
- All documents needed for a subsequent review should be recorded,
- Only validated and accepted references (design inputs, as-built drawings, system design description, etc.) should be used,
- Chosen strategies and assumed means (systems, structures, components) should be independently reviewed,
- Complete supporting analysis/reviews (setpoints calculations, chosen flowpaths, etc.) should be archived for a reasonable period of time.
Current plant status It is known that general requirements of QA for preparation of safety related procedures are in place at the plant. Some information on QA aspects was provided during the Prague Workshop in the context of verification the new symptom based EOPs [Hončarenko 03].
It was stated that this process followed INPO guidelines [INPO 83-004]. Most of the QA principles mentioned above were followed. These include requirements on using qualified staff in the process of development and verification, independent reviews, strictly defined criteria for the evaluation of discrepancies, documentation of verification process, etc. Given this background, it is reasonable to assume that similar QA rules will be applied in the implementation of SAMGs.
Evaluation Based on the information on QA principles applied at Temelín for the development of EOPs and considering the considerable experience gained in this area it can be expected that QA aspects will be satisfactorily addressed also in relation to SAMGs.
3.6.2 Internal and External Reviews VLI No. VLI title / description 7.2.1 Have internal and external reviews been conducted at various stages of SAMG development and implementation? Have the recommendations been implemented?
7.2.2 What mechanisms and administrative arrangements have been in place to identify potential shortcomings of SAMGs?
7.2.3 What mechanisms and administrative arrangements have been in place to ensure effective feedback from these reviews?
74 ETE Road Map - Preliminary Monitoring Report – Item 7b: Severe Accidents Related Issues State-of-the-art requirements and practices Internal and external reviews and approval are important element of QA process. It is relevant that internal reviews are performed starting from early phase of SAM development.
Identified strategies should be subject to a careful technical review by operating plant staff with broad knowledge of the plant design and safety case as well as operational aspects. Staff with good knowledge of accident phenomena and SA calculations (Department of Engineering Support) should also be involved. The existing plant Safety Committees can also play an important role.
Final instructions of the SAMG package (also the translated version) should be reviewed with respect to human performance aspects focusing on clarity of procedures (step-by-step format, use of checklists and place keeping aids, etc.). Staff responsible for this part of the review should have broad knowledge of plant design and more specific knowledge of human factor issues and ‘good practise’ in procedure writing.
External review should be conducted at the later stage of the SAMG development, preferably when the whole SAMG package is completed. The reviewers should have experience in the development and implementation of SAMGs. Review would also be desirable with regard to the validation exercise.
Administrative arrangements should be in place at the plant to ensure identification of potential shortcomings and effective feedback from all the reviews.
Current plant status It was stated during the Prague workshop that the SAMG package will be subject to internal review by the team independent from the team involved in the development [Sỷkora 03 b].
No information was provided on reviews at intermediate stages of SAMG preparation.
Evaluation Evaluation of this aspect is of limited scope due to lack of detailed information relating to the plant specific situation. However, it can be expected that experience gained by the plant staff so far (in the development of EOPs) will be satisfactorily used.
3.6.3 Organisation and Conduct of SAMGs Validation Tests VLI No. VLI title / description 7.3.1 Have validation exercise been conducted? If not, what arrangements are planned?
7.3.2 Was the validation exercise properly designed in order to verify the completeness and adequacy of the guidelines, and its good perception in conditions corresponding as close as possible to real severe accidents?
Which accident scenarios were selected for the validation exercise?
7.3.3 Is the documentation of the exercise comprehensive (covering the preparation, conduct, results, insights, and conclusions)?
7.3.4 Have all the lessons from the exercise properly analysed and used to propose improvements of the guidelines?
7.3.5 Did the selection of accident scenarios for validation exercise allow for testing relevant parts of the SAMG package and roles of different users?
ETE Road Map - Preliminary Monitoring Report – Item 7b: Severe Accidents Related Issues 75 State-of-the-art requirements and practices The validation exercise should be properly designed in order to verify the completeness and adequacy of the guidelines. This should include demonstration of its good perception in conditions corresponding as close as possible to real severe accidents. Consideration should be given to relevant aspects including the selection of accident scenarios used in the exercise, its preparation and conduct, documentation of the exercise, and feedback of lessons learned.
The selection of accident scenarios should allow for testing relevant parts of the package and roles of different users. The documentation of the exercise should be comprehensive. It should cover the preparation, conduct, results, insights, and conclusions. All lessons from the exercise should be properly analysed and used to propose improvements of the guidelines.
Current plant status The validation process for SAMGs at Temelín is in the planning stage [Sỷkora 03 b]. No information was provided on the details related to this process.
Evaluation The plant has considerable experience in the validation of EOPs. The plant is also expected to receive considerable support from the Westinghouse Company, which was directly involved in the preparation of SAMGs and has both appropriate expertise in SAM and knowledge of the plant. It can be expected that this process will be carried out satisfactorily. This aspect should be subject to detailed independent review (e.g. by IAEA RAMP mission), which would be conducted when the implementation process is finalized.
3.6.4 Provisions for Systematic Revision and Update of SAMGs
VLI No. VLI title / description 7.4.1 Are appropriate arrangements/procedures in place at the plant to review the SAMG package in the future?
7.4.2 Is there a well defined and formalized programme for conduct of reviews and their execution at regular intervals?
7.4.3 Is there a formalized programme to capture new insights, changes in technology and modifications of the plant?
State-of-the-art requirements and practices Appropriate administrative arrangements should be in place at the plant to review the SAMG package in the future. These reviews should focus on the modifications of the plant addressing eventual changes of the plant equipment and interrelated procedures. Provisions should also be made to capture new insights and changes in technology.
The reviews should be conducted according to a well-defined and formalized programme and executed at regular intervals. The existing administrative procedures on the review of plant procedures can support this process.
Current plant status Arrangements for periodic reviews of SAMGs and their updating are planned to be established. This issue was specifically mentioned in one of the presentation provided at the Prague workshop [Sỷkora 03 b].
76 ETE Road Map - Preliminary Monitoring Report – Item 7b: Severe Accidents Related Issues Evaluation It can be expected that appropriate arrangements for periodic reviews of SAMGs will be established in due time. A five-year SAMG update cycle was discussed at the Prague workshop, with consideration of final design changes as they occur.
This aspect should be addressed within an independent review, which would be conducted when the implementation process is finalized (e.g. by IAEA RAMP mission).
3.6.5 SAMGs-Related Staffing and Qualifications of the Staff
VLI No. VLI title / description 7.5.1 Have staffing/qualification requirements been identified and documented?