Improvement of TEPCO’s ALARA Process Shiro TAKAHIRA Tokyo 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 Plants Unit Type Capacity (MW) Commercial Operation Start No.1BWR-3460Mar.1971 No.2BWR-4784Jul.1974 No.3BWR-4784Mar.1976 No.4BWR-4784Oct.1978 No.5BWR-4784Apr.1978 No.6BWR-51100Oct.1979 No.1BWR-51100Apr.1982 No.2BWR-51100Feb.1984 No.3BWR-51100Jun.1985 No.4BWR-51100Aug.1987 No.1BWR-51100Sep.1985 No.2BWR-51100Sep.1990 No.3BWR-51100Aug.1993 No.4BWR-51100Aug.1994 No.5BWR-51100Apr.1990 No.6ABWR1356Nov.1996 No.7ABWR1356Jun.1997 Fukushima Daiichi(1F) Fukushima Daini(2F) Kashiwazaki Kariwa(KK)

Exposure Trends in TEPCO Person-SvNo. of Person Fukushima Daiichi NPS Fukushima Daini NPS Kashiwazaki Kariwa NPS

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 Collective Dose in FY2005 (Person-Sv/yr ・ reactor) Fukushima Daiichi （１ Ｆ） 2.6 Fukushima Daini （２Ｆ） 1.1 Kashiwazaki Kariwa （Ｋ Ｋ） 1.3

Benchmarking

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

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 Expected performance 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 output input Future schedule Past performance input New process Expectations Vision of site dose performance

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 and annual dose plans annual dose plans RWA Review / approval Outage dose plan Tracking dose RWA report Outage report RP proposal Involved 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

Summary Expected 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.