koeberg npp: severe accident management improvementssteam bunkers (sg pressure control) electrical...

Koeberg NPP: Severe Accident Management Improvements Rev 1

Dr Lindley Perryman

Eskom

Presentation Outline

• Introduction (2 slides)

• Shutdown & Spent Fuel Pool Accident Management (2 slides)

• Extreme Hazard Accident Management (5 slides)

• Severe Accident Management Training (1 slide)

Slide 2

Koeberg NPP 2 x 970 MWe PWRs commissioned in 1984 & 1985

Koeberg NPP SAM Background

• 1995: First implementation of Severe Accident Management Guidelines.

• 2006: Updated to include Reactor Shutdown accidents and Spent Fuel

Pool accidents.

• 2012: OSART SAM review results:

• No Recommendations or Suggestions,

• 2 Good Practices.

Slide 4






Slide 5

Shutdown Accident Management

Accident Severity

Normal

Operation

Transient Loss of

cooling or

Inventory

Core

Uncovery

High

Containment

Radiation

Vessel

Failure

Containment

Failure

Main

Control

Room

Technical

Support

Centre

Operating Procedures

Emergency Operating

Procedures (I.RRA-2 & 3)

Technical Support

to Control Room

Severe Accident

Management

Guidelines

(SAGs 3 to 7 & SCGs)

Local on-site

actions Support Guidelines: Local Action Sheets

(e.g., LAS-46, LAS-62 & LAS-64)

Emergency

Control Centre Emergency Plan

Spent Fuel Pool Accident Management

Accident Severity

Normal

Operation

Transient Loss of

cooling

Pool Boiling Fuel

Uncovery

Zircalloy

oxidisation

Radioactive

Releases

Main

Control

Room

Technical

Support

Centre

Operating / Incident

Procedures

Emergency Operating

Procedure (I.PTR)

Technical Support

to Control Room

Severe Accident

Management

Guidelines (SAG-8)

Local on-site

actions Support Guidelines: Local Action Sheets

(e.g., LAS-46, LAS-55 & KEP-89)

Emergency

Control Centre Emergency Plan






Slide 8

High-Level Extreme Hazard Mitigation Philosophy

Plant Operating Locations

MCR Main Control Room

CEMPs Cliff Edge

Management Points

ECPs External Connection

Points

Mitigative Equipment Location/ Storage

Installed Plant Equipment

Fire Station

On-Site Portable Equipment

Storage

Off-Site Accident Mitigation Storage

Depot

Command Location

MCR / Shutdown

Panel

TSC / ECC

Alternative ECC

(Bellville)

Dis

tan

ce

Slide 9

Cliff Edge Management Points (CEMPs) External Connection Points (ECPs)

CEMPs & ECPs

C & C

Communication Links

Main Control Room

Technical Support Centre

(Emergency Control Centre)

AFW Control Valve Room

(SG Feedwater

Control)

Steam Bunkers

(SG Pressure Control)

Electrical Building 7m

Level

(Shutdown Panel and

Switchgear)

Hot Penetration

Room

(RCS Injection Control)

External Connection

Points (ECPs)

(e.g., Make-up to SG, RCS &

SFP)

CEMPS & ECPs provide

decentralised hardened

mitigation Slide 10

Command

and Control

External Connection

Points

Internal Critical

Local Action

Management

Points

High-Level Extreme Hazard Mitigation Overview

Unit 1

ECP

Unit 2

ECP

Unit 2

ECP

Unit 1

ECP

Unit 1

Control

Room

Unit 2

Control

Room

Unit 1

7m

Level

Unit 2

7m

Level

TSC/

ECC

Unit 1

SG Inj.

CEMP

Unit 1

RCS Inj.

CEMP

Unit 2

RCS Inj.

CEMP

Unit 2

SG Inj.

CEMP

Unit 1

Steam

Bunker

Unit 2

Steam

Bunker

1. SG Injection

2. SFP Make-Up

3. RCS Injection

4. Containment Spray

External Connection Points (ECPs)

Slide 12

• Containment Spray (& RCS injection) external connection point for the use of mobile equipment.

• Similar connection points are provided for the SGs and the SFP.

• Diesel generator connection points planned.

CEMP (& ECP) Design Considerations

Hazards Robustness

Seismic Flooding Tornados and Extreme Wind

Loss of Electrical Power

Loss of Cooling

Accessibility Easy Access

Routes Access Route

Lighting Debris-Free

Routes Debris Removal

Equipment

Lighting Fixed

Emergency Lighting

Portable Emergency

Lighting

Portable Flood Lighting

Lighting Back-Up Power Supplies

Communication Air-phones Satellite Phones

Radio Back-Up

Charging Power supplies

Ventilation Operator

Habitability

Equipment Cooling

Requirements

Chemical Release

Protection

Radioactive Release

Protection

Equipment Staged Tools Protective

Equipment and Clothing

Equipment Back-Up Power

Supplies

Portable Ventilation Fans

Debris Removal Capability

Procedures Local Operating

Procedures Key Parameter

Indication

Communication with Command

and Control CEMPs

Indication Local Key

Parameters

Centralisation of Critical

Parameters

Indication Back-up Power Supplies

Slide 13






Slide 14

Provide comprehensive SAM training

Formal Program for SAMG User Qualification:

• Initial Qualification Training:

• Classroom site-specific training with table top exercises with specified entry

requirements related to the number of years of experience in accident

management,

• TSC equipment familiarisation.

• Annual Exercises and Drills:

• Severe Accident Management exercises,

• Emergency Response (including SAM) exercises,

• Exercises scope multiple units, reactor shutdown

states and the spent fuel pools.

• Annual Classroom Training:

• Classroom training with table top exercises,

• Plant walk downs of Local Action Sheets and

plant equipment used in SAM.

Slide 15

koeberg npp: severe accident management improvementssteam bunkers (sg pressure control) electrical...

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