- Korea’s largest power generator and the sole utility for nuclear power

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 Who is KHNP?

▶ KHNP: Korea Hydro & Nuclear Power Company

- Korea’s largest power generator and the sole utility for nuclear power

▶ Established: April 2001 (separated from KEPCO)

▶ Facilities: 82 [Nuclear(24), Pumped Storage (51), and Renewable (7)]

▶ Employees: 10,107 (as of June 2015)

Credit Ratings : Moody’s (Aa3/Positive), S&P (A+/Stable), Fitch (AA-/Stable)

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Seoul

In Operation

Under Construction Planned

(As of June 2015)

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5 KORI 1

1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025

KORI 3,4 HBN 1,2

HBN 3,4

HUN 3,4 WSN 2,3,4

HBN 5,6

HUN 5,6

SKN 1,2 SWN 1

SWN 2 SKN 3,4

SHN 1,2

SKN 5,6 SHN 3,4

p

O

C

32

28

24

9

3

PWR PHWR

APR1400

OPR1000+

OPR1000 (KSNP)

Component Approach

Turn-Key

TMI

(1979)

KORI 2 WSN 1

HUN 1,2

Chernobyl

(1986)

Fukushima

(2011)

PWR 1400MW X 4

PWR 1000MW X 4

PWR 1000MW X 8 PHWR 600MW X 3

PWR 900MW X 6

PWR/PHWR 600MW X 3

* P : Planned, O : Operation, C : Construction

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Part 1 Overview of the Fukushima Accident

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Fukushima #1

Fukushima#2

√ distance from epicenter / resistance to earthquake(g) : 150km / 0.37g

√ distance from epicenter / resistance to earthquake(g) : 160km / 0.37g

NPP Rx SFS Contai-

nment R/B

1 M ^AN ^I F

2 M ^AN ^F ^I

3 M ^AN ^I F

4 ^No-Fuel ^AN ^No-Fuel F

* M : Molten, AN : Abnormal, I : Integrity, F : Fail

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Automatic Rx trip Start-up of EDG

EDG

Turbine Building

Reactor Building

Earthquake occurred

1

Hydrogen explosion

4

Fuel overheated

from the loss of cooling

3

Station blackout

due to Tsunami

1 2

②

④

③

* Root Cause : Failure of reactor cooling due to station blackout

* EDG : Emergency Diesel Generator

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Part 2 Post-Fukushima Measures

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14 member countries and 20 regulatory experts

Reviewed the Korean regulatory system (July 10- 22, 2011) 44 internal & external experts

Integrity of 4 critical areas of the plant - On/Off-site power and core cooling - Containment and spent fuel pool

73 external experts and regulatory body Inspectors (for 21 nuclear units in operation)

* IRRS : Integrated Regulatory Review Service

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Government’s direct involvement in the post- Fukushima measures

An independent organization under the direct control by the President of Korea

Strengthens the national radiation emergency and disaster response

Safety-First corporate policy

Role reinforcement for nuclear safety

& disaster response

Running a Post-Fukushima TFT

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46 items

Joint Government-KHNP Team Identified (considering maximum earthquakes and tsunamis)

10 items

KHNP added

(from self-checks and overseas experiences)

Year ‘11 ‘12 ‘13 ‘14 ‘15 Total

Safety Check

(Government) 4 18 8 4 12

46

Additional

(KHNP) - 2 - 3 5

10

Total 4

(Finished) 20

(Finished) 8

(Finished) 7

(Finished) 17

(4Finished)

56 56 Items

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Emergency Response

Additional radiation protective equipment for the sake of residents

11 Earthquakes and Tsunamis

ASTS

Height extension of NPP sea wall

20 Severe Accidents

Passive hydrogen removal

equipment or ventilation facilities in the CV

Reinforcement of the SAMGs

10 Electrical Power and Cooling Ability

Mobile generator vehicles

Injection loop for SFP emergency cooling water

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2012

2013

2014

2015

 Extension of the sea-wall of Kori NPP

 Ensuring countermeasures when the cooling function of SFP is lost

 Reinforcing the radiation emergency training

 Improving plant seismic capacity

(e.g. seismic event alarm window in the control room)

 Investigating design basis of the sea water level of sites

 Preparing inundation prevention and restoration methods for loss of ultimate heat sink

 Installing passive hydrogen removal equipment

 Evaluating protective measures for residents

 Reinforcing the performance of emergency alarm facilities

 Installing ventilation or depressurizing facilities in the CV

 Installing conduits for injecting nuclear reactor emergency cooling water from external sources

* CV : Containment Vessel

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Part 3 Major Improvements

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Sea

wall ^Water-_proof Door

Diesel-driven Pump

PAR

CFVS

Reactor Emergency Cooling

SFP Emergency cooling

Mobile Generator REACTOR

Building

REACTOR Steam

Generator

EDG

SEA

① Height extension of the seawall at NPP

② Waterproof doors

③ Waterproof drain pumps (diesel-driven)

④ Mobile generator vehicles

⑤ External injection emergency cooling loop

⑥ Injection loop for SFP

⑦ Passive hydrogen removal equipment

⑧ Vent or depressurizing facilities

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Installed Automatic Seismic Trip System in the 24 NPPs in Korea

- Incorporate automatic reactor shutdown system for earthquakes exceeding a certain seismic level (0.18g)

 ASTS ensures a reactor is always tripped upon an occurrence of

the SSE, and yet prevents spurious trips during normal plant operations.

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Raised seawall heights of Kori NPP to the height level of other NPP sites reflecting evaluation results

Installed waterproof gates and waterproof drainage pumps in major structures to prevent possible inundation

19

5.8m 7.5m

E.L 5.8m E.L 7.5m E.L 10.0m 2.5m

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Equipped one vehicle-mounted emergency generator per site in a safe place and secure separate DC control power for flooding

Expanded the fuel supply capacity of an alternative emergency diesel generator considering multi-unit failure

Capacity : 3.2MW

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Installed a connection point at SFP building so as to allow a fire engine to inject water to the spent fuel pool

- The importance of the cooling of spent fuel and the need to secure additional SFP

cooling injection

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Installed PAR that can operate without any power supply based on earthquakes DBA and equipment survivability & equipment operability in SA

Installed CFVS within a containment building

NPP DBA SA

Total

L M S L M S

Kori (3 units) 4 4 - 42 10 10 70 Hanbit (6 units) 12 - - 70 52 8 142 Hanul (6 units) 12 - - 82 76 - 170 Wolsong (3 units) - 6 12 12 39 24 105

* PAR : Passive Autocatalytic Recombines, DBA(Design Base Accident), CFVS : Containment Filtered Vent System)

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* SBO (Station Blackout), LUHS (Loss of Ultimate Heat Sink)

Areas

Guideline

①Earthquake ②Tsunami ③Loss of Safety Functions(SBO+LUHS)

④Severe accident Management ⑤Emergency response

NSSC ‘s Stress Test Specifications of (2013.04.30)

Operator

Self-Assessment

① Adequacy Reviews

(including plant walk-down)

② Detailed Reviews

(regulator + private experts)

NSSC Reviews

Step 1 Step 2 Step 3

‘13.9.1

Step 1 Step 2

‘13.12.20 In progress

KORI-1

COD : 1978

‘13.5.1

Step 2

Step 1 Step 3

‘13.7.12 ‘14.12.12 ‘15.2.27

WOLSONG-1

COD : 1983

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Test Area

Earthquakes Floods

Loss of safety functions (SBO+LUHA)

Severe accidents

Earthquakes Floods

Loss of safety functions (SBO+LUHA)

Severe accidents

Emergency Response

Main Inspector

NPP operator NPP operator & Regulatory Body

Results Review &

Suggestions

Regulatory Body Regulatory Body

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YEAR 2015 2016 2017 2019 2020 TOTAL

Equipment

Reinforcement 1 3 4 1 - 9

System

Improvement - 1 1 - - 2

Long-term

Studies 2 1 2 1 2 8

SUM 3 5 7 2 2 19

These 19 items do not require immediate actions to secure Wolsong #1

NPP’s life extension, but are recommended to improve its long-term safety.

KHNP has established a long-term safety improvement plan

and its response capacity for extreme natural disasters will be strengthened.

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Part 4 Safety Enhancement Plan

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Government: 46 items KHNP: 10 items

Post-Fukushima Measures

Enhanced response for Extreme Natural

Disasters

2012

2015

21 items of 5 categories Emergency response team Emergency response center Follow-up of Stress Tests

Enhanced response for Multi-unit Accidents

2013

2014

Securing Response of BDBA Evaluation of plant status Reinforcement of fire response equipment Reinforcement of mobile equipment

Ensuring plant safety in Every Type of Disasters

2015

2020

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Quantitative real-time assessment of the safety level Performance monitoring/maintaining of main system

Comprehensive Nuclear Safety Assessment (Reflection of plant operation condition)

Re-check the safety of the latest technical standard

Check the next 10 years to secure safety

Perform impact mitigation measures, in preparation for severe accident

Development of SAMG for lower power operation during shutdown period

Development of connection guideline between EOP and SAMG

Prevent ion Mitiga tio n

Shot-term (real-time)

Mid-term (5~10year)

Long-term (10year)

Emergency

response

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Part 5 Summary

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Control the Electric Power

Step 1* Step 2*

▪ ASTS

▪ Mobile generator vehicle

▪ Waterproof door

▪ Raised seawall height

▪ (+) mobile cars (multi units)

▪ Improve firefighting abilities

▪ (+) power and instruments (PHWR, SCR)

Core Cooling

Step 1 Step 2

▪ External injection line (Core, SFP)

▪ Seismic resistance(↑) - core cooling equipment

▪ (+) mobile pumps

▪ Additional supplements (SFP cooling capacity)

Contain the F.P inside C.V Communication, Culture, etc.

Step 1 Step 2

▪ Secure additional equipment

(prolonged emergency)

▪ Improve emergency response facilities

▪ Reinforce emergency alarm facilities

▪ Secure emergency response organization

▪ Secure emergency response facility

▪ Secure

communication for long-term power loss

Step 1 Step 2

▪ CFVS(PHWR)

▪ PAR

▪ Revise SMAG

▪ SAMG

(Low-Power Shutdown)

▪ CFVS(PWR)

▪ SAMG

(Long-term Shutdown)

4C

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