Verification and Validation of Accident Management Guidelines in Indian PHWRs

Transcription

1 Verification and Validation of Accident Management Guidelines in Indian PHWRs By RS&A, NPCIL Mumbai, India IAEA Headquarters, Vienna, Austria, December /20

2 NPCIL Nuclear Power Corporation of India Limited is a Public Sector Enterprise Under the administrative control of the Department of Atomic Energy (DAE), Government of India. NPCIL is responsible for design, construction, commissioning and operation of nuclear power reactors. NPCIL is presently operating 20 nuclear power reactors with an installed capacity of 5780 MW. Currently NPCIL has five reactors under various stages of construction/commissioning totalling 3800 MW capacity. IAEA Headquarters, Vienna, Austria, December /20

3 Introduction Having (severe) accident management guidelines in place is a requirement (AERB Codes) There are uncertainties in scenario of severe accident progression and severe accident modeling and analysis. Regulatory Guides call for best estimate approach AERB Codes give high level requirements for consideration of severe accidents and preparation of severe accident management guidelines. NPCIL has indigenously developed document on accident management and it ascertained that guidelines developed for Indian PHWRs are in general similar to the one developed by CANDU utilities. IAEA Headquarters, Vienna, Austria, December /20

4 Basis Document Contents Severe accident analysis Training Accident Management Guidelines AMG Document is compiled in two volumes Volume-I : Generic Technical Basis Document Volume-II: Station Specific Accident Management Guidelines AMG includes objective and identification of accident management guidelines, both in Preventive Mitigating domains IAEA Headquarters, Vienna, Austria, December /20

5 Accident Management Document Preparation Volume-1: Generic Technical Basis Document Covers all the designs of Indian PHWRs Basis for back ground information Deterministic Safety analysis of severe accident scenario Comprehensive training material Volume-2: Station Specific AMG 3-4 days workshop for individual station personnel Basis is taken from Volume-1 Includes Station specific features Independent review and feedbacks taken from each station and followed by review in HQ and concurred by independent station review committee. IAEA Headquarters, Vienna, Austria, December /20

6 Preparation of Document IAEA Headquarters, Vienna, Austria, December /20

7 Probabilistic and Deterministic Safety Analyses PSA Dominant Sequences are Identified Deterministic analysis Entry and Exit to AMG Navigation Chart Time Available Containment Response Dose estimations for equipment survivability assessment and for corrective action IAEA Headquarters, Vienna, Austria, December /20

8 Accident Management Training One day Seminar at Each station before implementation of accident management guideline Accident Management Trainers Training Programme at HQ 4 programs 20 faculties is trained per programme All these trainers are connected in a forum for continuous feedbacks and discussions. Accident Management syllabus is included in the qualification of plant personnel Plant Walkdown IAEA Headquarters, Vienna, Austria, December /20

9 Human Factors under Severe Accident Conditions Cognitive Mindfulness Situation awareness Communication (in stressful situations) Decision making Adversity quotient Positive psychological capital Emotional Emotional intelligence Stress management Behavioral Crisis Leadership Followership Effective teamwork Situation Awareness Mindfulness Associated Human Factors Requirement Assessment of Situation Associated Uncertainties Resource Limitation Unseen Condition Associated Human Factors Communication Teamwork Decision making Leadership Followership Complex Situation Explicit Procedure Not Available Ability to Handle Adverse Situation Requirement Severe Accident Situation Requirement Collective Handling of Situation IAEA Headquarters, Vienna, Austria, December 2016 Adverse Radiological Conditions Immediate External Help Not Available Adversity Quotient Positive Psychological Capital Emotional Intelligence Stress Management Associated Human Factors Requires Unconventional Ways to Handle 09/20

10 Verification AMG includes templates for preparing procedure Computational aids Instrumentation aids Guidelines for reviewing and mode of revision. IAEA Headquarters, Vienna, Austria, December /20

11 Guidelines for reviewing and mode of revision IAEA Headquarters, Vienna, Austria, December /20

12 Validation Plant Exercises/Mock-up Drills Integrated exercise Table top exercise IAEA Headquarters, Vienna, Austria, December /20

13 Plant Exercises/Mock-up Drills This exercise is done to demonstrate that water can be arranged from water sources (nearby lake/river/onsite water storage for UHS maintenance) to one of the identified hookup points. Mock exercise for checking adequacy of mobile pump with the hookup points IAEA Headquarters, Vienna, Austria, December /20

14 Integrated exercise Following are the objectives of integrated mock up exercise:- To verify and validate accident management guidelines, use of navigation chart, computational and instrumentation aids, use of accident management provisions. To demonstrate capability to safely handle progression of accident in both units simultaneously by way of terminating and/or mitigating the accident. To assess communication effectiveness between various groups involved in accident management. To assess time required for providing alternate water. IAEA Headquarters, Vienna, Austria, December /20

15 Integrated exercise Photographs of measuring RTD resistance To assess time required for mobilizing air-cooled DG set to the specified point, laying of cables, starting of the DG set on no load and simultaneously charging of unit-1and unit-2 emergency power panels, keeping the main plant electrical system isolated. To assess time required for normalization of hook-up connections. IAEA Headquarters, Vienna, Austria, December /20

16 Table top exercise A tabletop exercise is a discussion type/role play exercise conducted around a table. Main objectives : i) Access to the Accident Management Guidelines (AMG) document. ii) The participants shall be able to use the guidance provided in the AMG to perform the evaluations. IAEA Headquarters, Vienna, Austria, December /20

17 Table top exercise ii) Apply the entry criteria and exit conditions for applicable guidelines. iii) Determine which strategies are available and applicable under current plant conditions. iv) Decide when to implement a guideline. v) Check the effectiveness of an implemented guideline and determine whether additional guideline should be attempted. vi) Use computational aids, as needed IAEA Headquarters, Vienna, Austria, December /20

18 Raj Interface of Accident Management Ritesh Programme and Emergency Response Plans Accident management guidelines is limited to implementing on-site actions to arrest accident progression. Emergency response plans include actions for implementing countermeasures within site and off-site based on actual measurement of radiation release rates inside and outside plant boundaries. Glimpses of Emergency Preparedness Exercises IAEA Headquarters, Vienna, Austria, December /20

19 Summary AMG Volume 1 is prepared and reviewed by regulatory. Station Specific Guidelines is available at all stations after complete review process. AMG syllabus is included in the qualification of plant personnel. Verification and Validation of AMG is done through Mockup drills Table top Exercises Integrated Exercises IAEA Headquarters, Vienna, Austria, December /20

20 Questions? IAEA Headquarters, Vienna, Austria, December /20