Improvement of TEPCO’s ALARA Process

Shiro TAKAHIRATokyo Electric Power Company

Radiation Protection Group

ISOE-ATC Symposium

October 12, 2006, Yuzawa, Niigata-pref., Japan

Contents

• TEPCO situations– Exposure trends– ALARA activities

• Improvement of Process– Objectives and Approach– Identifying gaps– Scope of Activities

• Improved Process– Mid-/long-term dose target process– Outage dose target process

Profile - Location

TEPCO’s Nuclear Power Plants

17 BWRs including 2 ABWRs (total capacity 17,308MWe) - 28% of generation capacity - 33% of generated electricity (FY 2004)

TEPCO’s Nuclear Power PlantsUnit Type Capacity

(MW)

CommercialOperation　 Start

No.1 BWR-3 460 Mar.1971No.2 BWR-4 784 Jul.1974No.3 BWR-4 784 Mar.1976No.4 BWR-4 784 Oct.1978No.5 BWR-4 784 Apr.1978No.6 BWR-5 1100 Oct.1979No.1 BWR-5 1100 Apr.1982No.2 BWR-5 1100 Feb.1984No.3 BWR-5 1100 Jun.1985No.4 BWR-5 1100 Aug.1987No.1 BWR-5 1100 Sep.1985No.2 BWR-5 1100 Sep.1990No.3 BWR-5 1100 Aug.1993No.4 BWR-5 1100 Aug.1994No.5 BWR-5 1100 Apr.1990No.6 ABWR 1356 Nov.1996No.7 ABWR 1356 Jun.1997

FukushimaDaiichi(1F)

FukushimaDaini(2F)

KashiwazakiKariwa(KK)

Exposure Trends in TEPCOPerson-Sv No. of Person

Fukushima Daiichi NPS

Fukushima Daini NPS

Kashiwazaki Kariwa NPS

0

20

40

60

80

100

70 75 80 85 90 95 00 05Fical Year

Occ

upat

iona

l Dos

e (P

erso

n-Sv)

0

3,000

6,000

9,000

12,000

15,000

Num

ber

of w

orke

rs

TEPCO’S ALARA Activities• Radiation Field Control

– Source term removal • Reduced corrosion products from feed water piping by

injecting oxygen

• Use of low-cobalt material

• Use of weatherproof steel in component materials for feed water and condensate system

• Dual condensate purification system

• Flushing and Chemical Decon.

– Shielding • Permanent shielding in PCV• Temporary shielding for high-radiation work

• ALARA Management

Annual Collective Dose

0

1

2

3

4

5

6

7

8

9

10

'80 '81 '82 '83 '84 '85 '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04

Year

Per

son

-Sv

J apan USA Sweden Spain Finland France Korea

Collective Dose in FY2005

(Person-Sv/yr・ reactor)

Fukushima Daiichi （１Ｆ）

2.6

Fukushima Daini （２Ｆ） 1.1

Kashiwazaki Kariwa （ＫＫ）

1.3

Benchmarking

Collective Dose in BWR 2003-2005 Average（ ）

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Tar

apur

Per

ry

Fuku

shim

a D

aiic

hi(6

)

Tok

ai-I

I

Qua

d C

ities

(2)

Cof

rent

es

Lagu

na V

erde

(2)

Nin

e M

ile P

oint

(2)

Rin

ghal

s

Bro

wns

Fer

ry(2

)

Col

umbi

a G

en S

ta

Ham

aoka

(4)

LaSal

le(2

)

Shi

man

e(2)

Tsu

ruga

Kuo

shen

g(2)

Fuku

shim

a D

aini

(4)

Dre

sden

(2)

Riv

er B

end(

1)

Pilg

rim(1

)

Shi

ka

Ver

mon

t Yan

kee

Pea

ch B

otto

m(2

)

Coo

per

(1)

Kas

hiw

azak

i Kar

iwa(

7)

Hop

e C

reek

Bru

nsw

ick

(2)

Gun

drem

min

gen

Npp

(2)

Chi

nsha

n(2)

Mon

ticel

lo

Clin

ton

Ferm

i

Gra

nd G

ulf

Mue

hleb

erg

Bru

nsbu

ette

l

Sus

queh

anna

(2)

Leib

stad

t

Fitz

Pat

rick

Kru

emm

el

Phi

lipps

burg

Oys

ter

Cre

ek

Dua

ne A

rnol

d

Hat

ch(2

)

San

ta M

aria

De

Gar

ona

Lim

eric

k (2

)

Isar

Osk

arsh

amn(

3)

Olk

iluot

o(2)

Fors

mar

k(3)

Ona

gaw

a(3)

Col

lect

ive

Dos

ePer

son-

(yr

reac

tor

)（

Ｓｖ／

・）

Top Quartile2nd Quartile3rd QuartileBottom Quartile

Objectives • Reshape ALARA Management by；

– Reviewing ALARA management “As-Is” process– Identifying a gap between “As-Is” and “To-Be”

process– Focusing on the interface between radiation

protection and maintenance staff at work planning and post-outage steps

Incorporating ALARA Considerations into Job

More Efficiently and Effectively!

• The project team “Dose Target Control Peer Team” organized

• Team Members– Leader : Radiation Protection Manager(H/O)– Permanent Members : Radiation Protection,

Radiation Safety, Chemistry staff from H/O , 1F, 2F, KK

– Temporary Members: Maintenance staff from H/O,1F, 2F, KK

Approach

Identifying Gaps

• Lack of mid- and long-term target

• Lack of inter-group communication between RP and maintenance group– Little RP staff involvement of work planning

and post-job performance review – Little chance to identify good practice and

to propose dose reduction measures for job

Lack of Mid- / Long-term Target

Vision

Expectations from the management(Division Director,Site President)

Projection of :•Each work dose•Outage dose•Annual dose

Mid- and Long-term Dose Plan

Lack of Interface

Annual dose plans

RWA Review / approval

Outage dose plan

Tracking dose

RWA report

Outage report

Long-term plan

Outage plan

Review detailed work schedule

Work management

Post-outage follow-up

Incorporation of lessons learned

Review main work schedule

Maintenance RP

Weak Relations

Weak Relations

Team Vision

The Dose Target Control Peer Team facilitates

the Maintenance Department and Radiation

Control Department as they jointly define

provisions to be implemented in each step of

maintenance processes(planning, scheduling,

work and evaluation), and communicate with

each other to evaluate planned and actual

figures in dose targets, thereby achieving dose

reduction.

Scope of Activities

Setting Outage Dose Target Process

Planning

Work

Check&Review

Follow-up Action

Setting Mid- and Long-term Dose Target Process Proposal for incorporating

dose reduction measures

Reviewing dose performance

Examining reflection items

for the next outage

Basic Policy for Mid- and Long-term Exposure

Reduction

Dose Target Plans for annual and Mid- /Long-term Exposure

Reduction

Maintenance

Process

Radiation Protection Management

Setting Mid- / Long-term Plans

Expectedperformance

Projected performance

The world’s top 25%

The world’s top XX%

The world’s top AA%

Mid- / Long-term and Annual Dose

plans

Basic Policy

out

pu

t

input

Future schedule

Past performance

input

input

New processNew process

Expectations

Vision of site doseperformance

Basic Policy

• Proposed by Radiation Protection & Management Group (head office)

• Approval of director of nuclear power plant management department(head office)

• Annually assess implementation results and determine the need for review

Ex.)World BWR’s top quartile of exposure reduction performance

Mid- / Long-term and Annual Dose Plans

• Proposed by Radiation Safety Group (Site)

• Approval of Site President

• Annually review

• Site president assesses “projected performance” by comparing with “expected performance”, and decides “vision of site dose performance”.

Interface between Maintenance and RP

Mid- /Long-term andMid- /Long-term and annual dose plansannual dose plans

RWA Review / approval

Outage dose plan

Tracking dose

RWA report

Outage reportOutage report

RP proposalRP proposal

Involved in work scheduleInvolved in work schedule

Long-term plan

Outage plan

Review detailed work schedule

Work management

Post-outage follow-up

Incorporation of lessons learned

Review main work schedule

Maintenance RP

RP Proposal

• Proposed dose reduction measures to maintenance team before outage contract

• RP Proposal– Effecting long-term or short-term(outage)

maintenance plans– For selected job (High radiation work)– Based on lessons learned at former outage

Involvement in Work Schedule• RP share information of detailed work

schedule with maintenance team and contractors.

• RP involvement– Suggestions for rearranging the work steps

which achieve significant dose reduction.– Providing dose information of the same

operation areas to maintenance team and contractors (Each job process optimally planned from the perspective of dose reduction).

Outage Report• Prepared by RP at post-outage follow-

up step and report out to maintenance team

• Including what maintenance team expect to know about outage jobs

• Involving following information – Dose performance of selected jobs– Proposals for dose reduction measures

that should be reflected to the next outage or other plants

– Punch lists for the proposal.

Implementation Program

• Mid- and long-term dose target process– Beyond FY 2007– Identifying site goal(slogan and target

value)• (ex.)World’s Top quartile at 20XX which means

yearly 1 person-Sv per reactor

– Draft document of basic policy and mid-/long-tern dose plan in this year

Process performance evaluated after implementation

Implementation Program• Outage dose target process

– Trial implementations this year– One or two plants of each stations for the

trial– Selected a couple of high radiation jobs of

each trial plants– Trial implementation identify validity of

process and issues before the start of full implementation

Process performance evaluated after trial implementation

SummaryExpected effects of process improvement ;• Setting “targets” in the basic policy as well

as mid/long-term and annual plans, will clarify the expectation of the management and the vision of exposure reduction.

• RP can provide more suggestions or feedbacks to the maintenance personnel in the outage dose target process by enhancing communications, then ALARA activities goes more effectively and efficiently.