SMOPIE - Work packages 2 and 3 Industry case studies and workplace categorisation Peter Shaw, HPA-RPD, UK

SMOPIE: Case Studies and Partners

Process materials: Bq/g

Industry Characteristics Large scale processes Dusty (in parts) Many process steps mechanical plant manual tasks multi-tasking All have workplace/individual monitoring all do air sampling (personal and/or static)

Personal air sampling (PAS) for dose estimates - UK1, UK2 and N1 (and F1) shift and task sampling radiometric and gravimetric Static air sampling (SAS) for dose estimates - F1 and N2 reassurance monitoring and particle size (N1) Real-time dust sampling (RTDM) SMOPIE surveys (not dose assessment) gravimetric and optical (particle counting)

Annual internal doses - Inhalation

Results and conclusions from different case studies Each case study is different Annex 2 to Main Report A lot of information strategies and methods results advantages and limitations practical tips Just a small selection in this presentation

UK1 - Zircon sand, grinding and milling Existing dust monitoring programme for many years (PAS) UK industrial hygiene regulations accepted by workers Results used to assess radiation doses Provided limited ALARA information dusty areas and tasks long terms trends More sampling recommended

UK1 - Real-time dust monitoring Specifically for the SMOPIE project 200 measurements in 2 days complete “map” of workplace day-to-day changes short-term variations localised dust levels dust sources tasks leaking pipes/vessels exhaust air from extractors cleaning machine!

UK1 R-T dust results - by location

UK1 R-T dust results - time variations

F1. Case Study - U concentrate conversion Comhurex, Malvési Different to other case studies activity concentration much higher radiation protection (nuclear) background rather than industrial hygiene Extensive monitoring programme SAS, urine and lung Focus on first step in the process sampling drums of U concentrates

F1. PAS campaign - sampling stage Drum unbanding/rebanding SAS v PAS both produce same rankings of dusty areas PAS doses 30-100 times higher important factors sampler location time profile of dust source of dust

Improvements to filling station F1 Case study Improvements to filling station hopper modified to prevent over-filling containment installed Effectiveness demonstrated by PAS (task) Problems with 1 drum type (from PAS/SAS) Real-time (optical) particle counting showing contamination peaks Further improvements at filling station drum handling equipment new (confined) rebanding station

F1. RT sampling inside filling station

N1 - phosphorus production

N1. Monitoring programme Focus on precipitator dust Leaching tests lung class S PAS (on 2% of shifts) alpha/beta counting 3 week delay 5 day count 245 results from 1998-2001

Doses categorised according to type of work N1 - PAS results Doses categorised according to type of work 0.1 to 2.8 mSv/y mean = 1.2 mSv/y Statistical uncertainties are important worker variation is greater than task variation varied work patterns changing air concentrations Only cleaners (2.8 mSv/y) and control room (0.1-0.2 mSv/y) show significant difference

Conclusions from WP2 Case Studies Categorisation of workplaces A strict categorisation is not helpful Instead focus on characteristics common to ALL case studies multiple dust sources, from machinery and workers airborne dust is always present dust levels always varying with space and time working patterns are complex and often change

Conclusions from WP2 Case Studies Monitoring strategies To implement ALARA assessment of internal dose, and information on how/where doses arise requires a combination of monitoring techniques Air sampling is better than other methods dose assessment and ALARA information Sampling uncertainties are significant are not considered enough in practice

Conclusions from WP2 Case Studies Monitoring strategies PAS provides best estimate of worker doses SAS to check doses are low (reassurance) underestimates, always compare with PAS Real-time not for dose assessment only suitable in certain workplaces can provide best ALARA information

SMOPIE - WP3 Categorisation of exposure situations Case studies indicated that categorisation was not helpful Same conclusions apply in all cases Some other factors to consider gravimetric analysis requires constant Bq/g alpha/beta counting requires contant radionuclide ratios Bq/g and dose coefficent influence choice of analysis method (sensitivity)