verification and validation of accident management ... • nuclear power corporation of india...

Verification and Validation of Accident Management Guidelines in

Indian PHWRs

ByRitesh Raj

RS&A, NPCILMumbai, India

[email protected]

Technical Meeting on the Verification and Validation of Severe Accident Management GuidelinesIAEA Headquarters, Vienna, Austria, 12–14 December 2016 01/20

Ritesh RajNPCIL, India

NPCIL• Nuclear Power Corporation of

India Limited is a Public SectorEnterprise Under theadministrative control of theDepartment of Atomic Energy(DAE), Government of India.

• NPCIL is responsible fordesign, construction,commissioning and operationof nuclear power reactors.

• NPCIL is presently operating20 nuclear power reactorswith an installed capacity of5780 MW.

• Currently NPCIL has fivereactors under various stagesof construction/commissioningtotalling 3800 MW capacity.



• Having (severe) accident management guidelines in placeis a requirement (AERB Codes)

• There are uncertainties in scenario of severe accidentprogression 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 ofsevere accident management guidelines.

• NPCIL has indigenously developed document on accidentmanagement and it ascertained that guidelines developedfor Indian PHWRs are in general similar to the onedeveloped by CANDU utilities.

Introduction



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 AccidentManagement Guidelines

AMG includes objective andidentification of accident managementguidelines, both in• Preventive• Mitigating domains



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 materialVolume-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 byindependent station review committee.

Accident Management Document Preparation



Preparation of Document



Probabilistic and Deterministic Safety Analyses

PSA• Dominant Sequences are Identified

Deterministic analysis• Entry and Exit to AMG• Navigation Chart• Time Available• Containment Response• Dose estimationsfor equipment survivability assessment and for correctiveaction



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



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

Technical Meeting on the Verification and Validation of Severe Accident Management GuidelinesIAEA Headquarters, Vienna, Austria, 12–14 December 2016

Severe Accident Situation

Unseen Condition

Complex Situation

Adverse Radiological Conditions

Resource Limitation

Explicit Procedure

Not Available

Immediate External Help Not Available

Requires Unconventional Ways to Handle

Associated Uncertainties

Requirement

Assessment of Situation

Requirement

Ability to Handle Adverse Situation

Requirement

Collective Handling of

Situation

Situation Awareness Mindfulness

Associated Human Factors

Adversity Quotient Positive Psychological

Capital Emotional Intelligence Stress Management



Communication Teamwork Decision making Leadership Followership

09/20


Verification

• AMG includes templates for preparingprocedure

• Computational aids• Instrumentation aids• Guidelines for reviewing and mode of

revision.



Guidelines for reviewing and mode of revision



Validation

• Plant Exercises/Mock-up Drills • Integrated exercise• Table top exercise



Plant Exercises/Mock-up DrillsThis exercise is done to demonstrate that water can be arrangedfrom water sources (nearby lake/river/onsite water storage forUHS maintenance) to one of the identified hookup points.

Mock exercise

for checking adequacy of mobile

pump with the hookup

points



Integrated exerciseFollowing are the objectives of integrated mock up exercise:-

To verify and validate accident management guidelines, use ofnavigation chart, computational and instrumentation aids, use ofaccident management provisions.

To demonstrate capability to safely handle progression of accidentin both units simultaneously by way of terminating and/ormitigating the accident.

To assess communication effectiveness between various groupsinvolved in accident management.

To assess time required for providing alternate water.Technical Meeting on the Verification and Validation of Severe Accident Management Guidelines

IAEA Headquarters, Vienna, Austria, 12–14 December 2016 14/20


Photographs of measuring RTD resistanceIntegrated exercise…

To assess time required formobilizing air-cooled DG set tothe specified point,

laying of cables, starting ofthe DG set on no load andsimultaneously charging ofunit-1and unit-2 emergencypower panels, keeping themain plant electrical systemisolated.

To assess time required fornormalization of hook-upconnections.



Table top exerciseA tabletop exercise is a discussion type/role play exerciseconducted 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.Technical Meeting on the Verification and Validation of Severe Accident Management Guidelines

IAEA Headquarters, Vienna, Austria, 12–14 December 2016 16/20


ii) Apply the entry criteria and exit conditions for applicableguidelines.

iii) Determine which strategies are available and applicableunder current plant conditions.

iv) Decide when to implement a guideline.

v) Check the effectiveness of an implemented guideline anddetermine whether additional guideline should be attempted.

vi) Use computational aids, as needed

Table top exercise…



Interface of Accident Management Programme and Emergency Response Plans

• Accident management guidelinesis limited to implementing on-siteactions to arrest accidentprogression.

• Emergency response plansinclude actions for implementingcountermeasures within site andoff-site based on actualmeasurement of radiation releaserates inside and outside plantboundaries.

Glimpses of Emergency Preparedness Exercises



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



Questions?

20/20Technical Meeting on the Verification and Validation of Severe Accident Management Guidelines

IAEA Headquarters, Vienna, Austria, 12–14 December 2016


verification and validation of accident management ... • nuclear power corporation of india...

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