Comparison of Performance Indicators of Different Types of Reactors Based on the ISOE Data H. Janžekovič, M. Križman

Overview Introduction Types of reactors Radiation protection performance indicators from the ISOE database Conclusions

Introduction The extent of control of an operation in NPPs is related to: a risk a potential risk taking into account emergency scenarios. Control of an operation of radiation safety contains three main categories: 1. radiation protection of workers 2. radiation protection of the population and the environment through control of discharges and direct radiation 3. waste management.

Introduction Control of radiation safety depends on the life period of an NPP: pre - operation phase operation decommissioning The efficiency of control can be measured by using performance indicators - PI. The PI should be well defined measurable parameters which will suit regulators as well as operators to follow the relevant radiation protection issue. Overviews of PIs can be found in the NEA/CSNI/R(2001)11 publication containing also the WANO performance indicators.

Introduction

Introduction The PI of an NPP strongly depends on: I. Physical characteristics of an NPP type of a nuclear power plant life period of NPP maintenance and upgrading of an NPP (steam generator replacement...) refuelling practice of an NPP. II. Management of radiation protection issues.

441 nuclear power reactors in operation in 32 countries producing Introduction In the world *: 31 under construction 441 nuclear power reactors in operation in 32 countries producing 358661 MW (e) *IAEA, Nuclear Power Reactors in the World (2003).

Types of Reactors Today, mainly 4 types or reactors are in commercial use: LWR (light water reactor) HWR (heavy water reactor - CANDU) GCR (gas cooled reactor) RBMK (light water graphite moderated reactor) In addition, LWR could be PWR (pressurised water reactor) including Russian type VVER BWR (boiling water reactor).

Types of Reactors

Types of Reactors In the year 2002, 321 reactors were in operation*. The total of operating experience was 6014 years. * ISOE Rev. 63

Types of Reactors

Types of Reactors

Types of Reactors * ISOE database

Types of Reactors PWR - Saint Alban 1, 2, France Picture taken from http://www2.ijs.si/~icjt/plants/index.html

Types of Reactors CANDU - Darlington, Canada Picture taken from http://www2.ijs.si/~icjt/plants/index.html

Types of Reactors GCR - Dungeness, United Kingdom Picture taken from http://www2.ijs.si/~icjt/plants/index.html

Types of Reactors RBMK - Leningrad, Russia Picture taken from http://www2.ijs.si/~icjt/plants/index.html

Types of Reactors In the year 2002, 43 reactors were shut down with the mean age of 19.4 year at the time of shut-down. * * ISOE database

Types of Reactors

Radiation Protection Performance Indicators from the ISOE Database The performance indicator related to the occupational dose is usually the collective dose in a time period or trend of the collective dose. Around 80% of all exposure is usually due to high dose jobs, which can be estimated to represent only about 20% of all jobs in NPPs. * *OECD, Work Management in the Nuclear Power Industry (1997)

Radiation Protection Performance Indicators from the ISOE Database Picture taken from http://www.nek.si/ (NPP Krško, PWR)

Radiation Protection Performance Indicators from the ISOE Database Widely used radiation protection performance indicators related to occupational exposure: distribution of individual dose (maximum, average, mean etc.) collective dose over a period collective dose related to a specific task normalised collective dose by energy production percentage of internal exposure in the total dose contamination of workers or working area hot spots characteristics...

Radiation Protection Performance Indicators from the ISOE Database The total collective dose in the year 2002 was 402.3 man Sv. The number of workers is approximately 500 000.* *UNSCEAR, Sources and Effects of Ionising Radiation (2000)

Radiation Protection Performance Indicators from the ISOE Database

Radiation Protection Performance Indicators from the ISOE Database

Radiation Protection Performance Indicators from the ISOE Database

Radiation Protection Performance Indicators from the ISOE Database Specific jobs contribute significantly to the occupational exposure. Picture showing the outage at the PWR NPP taken from the archive of the SNSA.

Radiation Protection Performance Indicators from the ISOE Database * The contributions are averaged over countries. *UNSCEAR, Sources and Effects of Ionising Radiation (2000)

Conclusions The comparison of performance indicators of different types of reactors based on the ISOE database shows: the mean age of operating reactors in 2002 was the highest for BWR and the lowest for VVER in 2002 the PWR participating in ISOE achieved 3769 years of operating experiences while the lowest value of this parameter was 35 years, valid for RBMK the annual collective dose for GCR shows a stable decrease in the last five years but not a stable trend for other types of reactors was observed

Conclusions cont. the normalised average annual collective dose per TWh is the highest for RBMK the contribution to the outage to the collective dose is in the range from 70 % to 87 % in 2002