EPRI Advanced Nuclear Plant Design Recommendations for Radiation Protection/ALARA

54th HPS Annual MeetingJuly 14, 2009Karen KimSr. Project Engineer

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EPRI Advanced Nuclear Plants Activities

• Radwaste Liquid processing strategy flexibility and solid waste minimization

• ALARA/RP Reduction of personnel dose exposure• Groundwater Groundwater Protection• Chemistry Source term reduction, component and

fuel reliability

Implement operating experience, lessons learned, and advanced technologies in the design, construction, and operation of new nuclear power plant for life of plant benefits regarding:

Benefit: Implementation of technically sound and cost effective technologies and methodologies.

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Image: Areva U.S. EPR

Past and Current EPRI Projects

Review of Westinghouse AP1000:– Review of Westinghouse AP1000 LLW

Management Program (TR-1008016, 2003).– AP 1000 Radioactive Waste Management –

Utility Position Report (TR-1008129 , 2004)– Mobile Processing and Treatment Systems

(2005)– Review of Westinghouse AP1000 ALARA/RP

Program (Continuing into 2008)

Review of GE ESBWR:– Technical Support for GE ESBWR Radwaste

System Design (TR-1013503, Nov. 2006 Blue Chip Deliverable)

– EPRI Review of the GE ESBWR ALARA/RP Design Provisions (Continuing into 2008)

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Past and Current EPRI Projects

Technical Support to NRC and NEI– Industry Review of DG-1145 (RG-1.206) Regulatory Guide for the

Combined Operating License Application (Fall 2006)• Radwaste and ALARA/RP Chapters

– DG-4012 Industry Recommendations for Regulatory Guidance to 10CFR20.1406: Minimization of Contamination (Spring 2007)• Groundwater Protection and Decommissioning• 25% of EPRI Recommendations Included in DG-4012.

EPRI Utilities Requirement Document (URD) for Advanced Plant Design– Review and Revision of Radwaste Chapter (2006-2007, COMPLETE)– Groundwater Protection Provisions (2007)– Review and Revision of Chemistry Provisions (2007, COMPLETE)– Development of ALARA/RP Section (2007-2008)

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ALARA/RP for Advanced Plant DesignJanuary 2008 Status Update

• Westinghouse AP1000 Review:– Top 8 High Impact Issues developed by EPRI ALARA/RP

Committee (2006-2007)– Top 8 High Impact Issues transmitted to Westinghouse Design

Team in collaboration with NuStart (Spring 2007)– NuStart and Westinghouse develop resolution/mitigation solutions

for Top 8 High Impact Issues (Summer 2007)

• GE ESBWR Review– Top 8 High Impact Issues developed by EPRI ALARA/RP

Committee (2007)

• EPRI URD ALARA/RP Revision (November 2007)– URD Revision developed.– Pending review by EPRI ALARA/RP Committee.

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ALARA/RP Considerations for New Plant Designs

SOURCE. TIME. DISTANCE. SHIELDING.

1. Personnel Exposure2. Source Term Reduction3. Remote Monitoring4. Component Shielding5. Component Accessibility6. Component Design7. Access Control to High Radiation Areas8. Groundwater Protection

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1) Personnel Exposure & 2) Source Term Reduction

• Meet decreasing industry personnel exposure goals:– 120 rem for BWR and 60 rem for PWR by 2010– US NRC consideration of 2 person-rem/yr limits

• Source Term Reduction:– Use of low-cobalt alloys in in-core instruments– Pre-treatment surfaces of all major primary system components (i.e.

electropolish & passivate)– Fuel cleaning– Zinc addition at initial startup by design– Reference EPRI Source Term Reduction Guidelines and Water

Chemistry Guidelines

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3) Remote Monitoring

• Remote Monitoring:– Teledosimetry & enhanced audio-visual monitoring and communications

capabilities for:• Radiation monitoring• Process monitoring• Waste storage inspection

– Improved technologies being implemented at current operating plants.– New plant infrastructure should be designed to support remote

monitoring.• Support for wireless and wired communications between buildings.• Include enough margin in design to accommodate new technologies

throughout the life of the plant– Reference: EPRI URD, EPRI Remote Monitoring Guidelines and Field

Implementation Reports.

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4) Component Shielding and 5) Accessibility

• Component Shielding:– Permanent shielding for systems & components that contribute to routine

worker exposure.• If permanent shielding is not possible, consider permanent supports

for temporary shielding.• Consider shielded insulation panels for components and piping where

needed and possible.

• Component Accessibility:– Permanent platforms, scaffolding, ladders– Services (lighting, water, air)– Adequate workspace, overhead clearance– Components should be oriented to facilitate operation and maintenance– Rigging, lifting, and transport of components and equipment

• Padeyes, monorails, cranes.

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6) Component Design

• Component Designs:

– Cartridge Filters• Design system or filters to last one full fuel cycle• Design filter and housing for change-out using remotely operated or

long-handled tools.

– Pump Design & Maintenance• Pumps should be modular• Facilitate pump maintenance and removal

– Provide for lifting and transport (padeyes, rigging, cranes, monorails; eliminate berms/curbs around pump)

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6) Component Design

• Component Designs:

– RWCU System Decontamination• Demins and filters shall be separately isolable and shielded so that

access to one will not require draining of the other.• Demins and filters should be configured to allow one to be used for

shutdown cleanup & isolated in-situ for a cycle for decay.• Designed to facilitate chemical decontamination to reduce radiation

levels in piping & components.

– System Piping & Routing; Tank Designs• Prevent buildup high solids/slurry/spent resin (that lead to hot spots)

in piping and tanks• Include provision for easy cleanout/decontamination for waste system

and other high solids (e.g. hydrolaser, self-traveling probe.)

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7) Access Control to High Radiation Areas

• Access Control to High Radiation Areas:– Component and system designs shall eliminate the potential for creating

accessible areas that are greater than 100 mR/hr during any plant operating mode. • (Specific exceptions include but are not limited to reactor and large

component internals, BWR TIP rooms, etc.)• Minimize or eliminate the need for plant personnel to enter the area

for routine operation (i.e. remote monitoring/operations)• Incorporating positive, physical controls to limit accessibility to 100%

of the affected area.

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8) Groundwater Protection

• Groundwater Protection:– Minimize building joints and seams

• Single pour construction of building foundations– Eliminate underground and embedded piping for transferring radioactive

liquids.• If underground piping is required apply engineering barriers to

prevent and detect leaks (i.e. pipe chases)• Document any underground piping with GPS technology

– Design spent fuel pool weld leak collection systems to facilitate location of leaks in liner.

– Outside tanks:• Concrete pads and bermed area that can contain 110% of the tank

capacity• Hard-piped overflows to receiving tanks or sumps

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Conclusion

• Identify high dose tasks and causes (from operating experiences and lessons learned) and implement solutions in new plant designs.

• Implementing these solutions during design/construction phase will obviate the need for (usually costly) retrofits during operation.