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Introduction • B&H authorities, in 1998, established Radioactive Waste Storage Facility in order to accommodate for a relatively long term period the disused sealed radioactive sources (DSRS) for which regulatory control was lost as a result of the war (1991-1995). • Since then, the Facility has been operated as the centralized radioactive waste storage facility. • The operator of the Facility has been the Institute for Public Health of FB&H . • The purpose of the Rakovica Facility is to provide for safe and secure storage of DSRS, mainly radioactive lighting rods (Eu-152/154), but also various industrial gauges and sources used in medicine. In addition, low level solid radioactive waste collected as a result of the incidents is stored.
SC Purpose • License application • Optimization of the dose received by the workers • As a basis for identifying measures to upgrade the facility for conditioning of the DSRS • SC assumes the envisaged lifetime for the facility of 10 years • In the CRWSF is not built within 10 years, IPH would make a submission to Reg. Auth. to amend the license to extend it for a defined period of time (i.e. re-licensing at 5 year intervals).
SC Scope • The SC supports the continued operation of an existing storage facility • The SC is focused on the as-built facility and its operational aspects • Demonstration of safety of facility and activities is addressed in SC
Safety Assessment (SA) • The assessment is carried out to assist in demonstration of safety • The assessment covers facility in its current and future operational status up to 10 years • Radiological safety criteria are taken from BOH radiation protection legislation • Considerations are given to the normal operation of the facility and to the accidental situations caused by disturbing events that can occur
SA approach • The radiological assessment is based upon realistic and conservative approach taking into consideration measured data where possible • When such data are not available SAFRAN code is applied to model exposure
SA Endpoints • Dose to workers • Dose to security personnel • Dose to public in nearby village
SA Scenarios • Development and justification of scenarios • Normal operations • Scenarios for accidents • Screening of the PIEs for the relevance • Creation of the PIE list and assessment for probability and relevance as a basis for the development of the scenarios • Creation of the scenarios and assessment for probability and relevance as an input for the possible impacts
SA Assessment Models • Formulation and implementation of assessment models • Normal operations - Exposures to the workers and police security is quantified taking into account external exposure • Accidents – Workers, fire fighters and remediation workers are identified as potentially exposed. Exposures are quantified taking into account selected sources, based on radiotoxicity and routes of exposure that can pose risk for the defined endpoints
SA Calculations and Analysis • Calculations are conducted for a given inventory of stored waste under different assumptions based on simple and conservative models and parameter values • Results of the assessments are compared to safety assessment criteria (dose limit to workers, 20 mSv/a and public, 1 mSv/a) • Normal operations, workers, 0.8-1.2 mSv/a • Accidents, workers, bare source Co-60, cat.III, ≈30 mSv/incident • Accidents, public, fire fighter, airborne release of Am-241, ≈70 mSv/incident
Comparison with Safety Criteria • Under normal operation the risk for the workers is within radiation protection legislative requirements • The public and environment are unlikely to be affected by normal operation and accident conditions in facility • In the case of unplanned loss of shielding, the time delay in detection of such a source has significant impact • In the case of a collection of the large number of low activity Am-241 sources from smoke detectors, significant exposures could occur if sources are not protected against direct heating in excess of 600°C
Unresolved Issues • The SC indicates some information and other gaps that need to be addressed in order to improve the ability of the SC to demonstrate safety and security
Unresolved Issues • Legal and regulatory framework • Sections of the SC need to be revised once any new regulations are fully implemented • Basic engineering analysis • Original documentation not available. Revise the SC in accordance with obtained information from relevant institutions and organizations • Optimization of protection • Development and implementation of formal operational optimization programme • Review of the Am-241 container with regards to its ability to withstand heat up to 600C and its ability to perform its containment function
Unresolved Issues • Non-radiological hazards • Plan and conduct a comprehensive non-radiological hazard assessment • Implemented waste management practice • Review and finalization of the WAC document • Integrated management system • Derive a plan for the development of the integrated management system • Management of uncertainties • Expand a confirmatory monitoring plan to verify the dose rate assumptions • Facility specific limits and conditions • Development of a procedure that lists the agreed limits and conditions as applicable to the various facilities and activities
SC Overall Results • The practical results are: • a structured summary of the important safety elements and functions, • an identification of a number of weaknesses in the safety, • ideas for improvements of the safety
SC Revision • Unresolved issues • Reliability of the information, reference inputs • Adequacy of the models (simple vs complex) • Quality of measured data/derived parameters • Review scenarios (expected and altered) • Uncertainty analysis (system description, model and data/parameter)
SC Development • Baseline/initial SC - for the initial two years (due to uncertainties in inventory and capacities for processing and storage) • Conditioning/intervention SC – for the processing of the stored waste • Operational SC – for the continuation of the operation of the facility • Retrieval SC – for the retrieval of the waste, decommissioning and closure of the facility
IAEA Assistance • AVILA, Rodolfo (SWE) • BACKELANDT, Luc (BEL) • GUSKOV, Andrey (RUS) • HEARD, Rob (SAF) • HOFMAN, Dmytro (UKR) • HOWELL, Eric Kellan (USA) • HUNT, Jeremy Gareth (UK) • METCALF, Philip Edward (SAF) • SELLING, Hendrik (BEL) • VISAGIE, Abraham Lodevikos (SAF)