Transcript No Slide Title

OPERATIONAL EXPERIENCE WITH A LEGAL
ELECTRONIC DOSIMETRY SYSTEM
Dr Tasos Zodiates
British Energy
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CURRENT BRITISH ENERGY STATUS
• 6 Stations Legal with the EPD Mk 1
• 1 Station close to Legal with the EPD Mk 2
• 1 Station to implement EPD Mk2 as Control Dosemeter
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British Energy’s power plants - 2004
British Energy HQ
(East Kilbride)
Hunterston B
1,195MW
Heysham 1
1,060MW
Torness
1,210MW
Hartlepool
1,205MW
Eggborough
2,000MW
Heysham 2
1,340MW
Hinkley Point B
1,270MW
Sizewell B
1,200MW
Dungeness B
1,120MW
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EPD System - Schematic Drawing
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EPD SYSTEM REQUIREMENTS
• Health Physics with computing skills
• Software/hardware support from Thermo
• Contingency arrangements:
–
–
–
–
contingency plan for any fault / event
local mode operation
data back ups: daily / every 15-20 min
server back up
• In house computing support: Windows / Oracle
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EPD Mk1 EQUIPMENT - TYPICAL STATION
NUMBERS
EPD Numbers
• Normal Operation: ~150
• Emergency Use: 50-80
• Outage Use: 350-450
Operate a Pool arrangement to support
3 coincident outages:
• Normal ops:
450
• Outage:
1200
• Emergency:
350
• Calibration/repair:
100
Total
2100
EPD Related Equipment
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•
•
•
Access Terminals: 8-12
Access Control Units: 4-6
Desktop Readers: 2
each station holds its own stock
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USES OF EPD SYSTEM - OUTAGE MONITORING
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USES OF EPD SYSTEM - OUTAGE MONITORING
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USES OF EPD SYSTEM - OUTAGE MONITORING
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EXPERIENCE WITH THE EPD Mk1
• User mishandling &
damaged/lost EPD
• battery problems:
• Beta Window Failure:
• RFI problems:
improving
resolved
being managed
design deficiency;
HYA improvements
RFI + Beta window result in a number of dose investigations
and amendments requiring effort from Health Physics
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EPD Mk1 2003 PERFORMANCE STATISTICS
Station
Total Visits
Dose Amendments
SXB
HNB
HYA
HYB
~ 50000
~ 170000
~ 132000
~ 109000
140
360
448
391
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SIZEWELL B EPD FAULT BREAKDOWN
RFI
Counter PCB
Beta Window*
Electrostatic Discharge
Mechanical Impact
Other
Total
58
23
19
16
8
16
140
* 13 Amendments due to one faulty EPD
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SIZEWELL B EPD FAULT BREAKDOWN
14%
11%
16%
RFI
6%
Counter PCB
Beta Window
17%
11%
Electrostatic Discharge
Mechanical Impact
42%
Other
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HPB EPD Mk2 EXPERIENCE COMPARISON
400,000 visits over 3 years:
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•
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1 dose amendment due to RFI (proximity to welding)
1 dose amendment due to damaged beta window
38 dose amendments due to EPD losing communications
9 dose amendments due to user losing EPD
Mk2 Generic Manufacturing/Design Defects
• top lid cracking
• flexiconnector / battery internal connector
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OTHER EPD ISSUES
Associated with Legal Status
• Approvals by Regulator - length of time
• System within the Station Modifications Process
Associated with Software
• Level of required computing support
• User driven software upgrades
• Cost & Resource for enforced software upgrades
(Microsoft Windows, Oracle)
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FUTURE DEVELOPMENTS
• All stations legal with EPD
• Transition to EPD Mk 2 ( 2004 - 2007?)
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smaller, lighter, more robust
overcomes RFI
cheaper batteries
more dosimetric information
• Move to Windows XP / Oracle 9i
• DCS4? Common EPD platform software for all UK users
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