power reactor occupational radiation safety the first 50 years ralph andersen, chp senior director...
TRANSCRIPT
Power Reactor Occupational Radiation Safety The First 50 Years
Ralph Andersen, CHPSenior Director – Radiation Safety & Environmental Protection
Health Physics Society - 59th Annual Meeting July 14 • Baltimore, MD
1
By Way of Introduction
HEALTH PHYSICS: The science concerned with the recognition, evaluation and control of health hazards from ionizing radiation.
2
In the Beginning
3
The Early Days 1969-1979
OccupationalDose Limit:1.25 Rem/qtror3 Rem/qtr w/ N-18
4
Rugged Individualism 1969-1979
• RP is responsible for RP • Minimal staffing, equipment and resources • Pen and paper technology• Variable training• Compliance driven• “Necessary Inconvenience”• Some knowledge transfer and information
exchange (e.g., EEI HP Committee)5
No. of Operating Power Reactors1969-1979
1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 19790
10
20
30
40
50
60
70
80
LWRPWRBWR
6
Average Collective Radiation Dose Per Reactor (Person-Sv) 1969-1979
1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 19790
1
2
3
4
5
6
7
8
9
LWRPWRBWR
7
Average Measurable Dose per Worker (mSv/a) Measurable Dose (mSv) 1969-1979
1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 19790
2
4
6
8
10
12
LWRPWRBWR
8
Individual Annual Dose Distribution (mSv/a) 1973-1979 Per Cent of Monitored Workers with Measurable Dose
1973 1974 1975 1976 1977 1978 19790
5
10
15
20
25
30
35
40
>10>20>50
9
1980-1990
OccupationalDose Limit:1.25 Rem/qtror3 Rem/qtr w/ N-18
10
Three Mile Island
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NRC HP Appraisal Program (NUREG-0855)
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NRC HP Appraisal ProgramExample Questions (RP Organization)
• Does the Radiation Protection Manager have a direct reporting chain to the Plant Manager?
• Does the RP organization have adequate authority to ensure the RP program is implemented (e.g., enforce adherence to procedures, stop work, etc.)?
• Is the overall staffing level of RP technicians adequate to perform assigned responsibilities with the workload existing during normal and outage conditions?
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NRC HP Appraisal ProgramAdvice to HPs
• Don’t be satisfied with a program that merely meets the formal regulatory requirements
• When something goes wrong and a problem surfaces, be sure to search for the cause
• Take the time and effort to ensure that RP staff are assigned specific duties for routine operations and emergencies
• Make sure that the RP staff develops a depth of knowledge and understanding of RP principles and practices
• Perform frequent audits of performance (versus compliance)• Emphasize effective and respectful communication
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NRC HP Appraisal ProgramAdvice to Young HPs
“Another common mistake made by many of the younger professionals is to treat the technicians as lowly subordinates. This attitude can be very costly for the young professional and can be disastrous to the program. Cooperation is built on trust and respect; it does not come automatically with academic degrees and positions.”
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Institute of Nuclear Power Operations (INPO)
• The nuclear electric industry created the Institute of Nuclear Power Operations in 1979. INPO’s mission is to promote the highest levels of safety and reliability – to promote excellence– in the operation of nuclear electric generating plants.
• INPO conducts periodic evaluations to promote the highest levels of excellence in the operation, maintenance, and support of operating nuclear plants. All evaluation visits are based on performance objectives and criteria, developed by INPO with industry input and review. The evaluations are performance-oriented, emphasizing both the results achieved and the behaviors and organizational factors important to future performance.
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INPO
• The National Academy for Nuclear Training, which operates under the auspices of INPO, embodies the U.S. commercial nuclear utility industry’s commitment to high quality training and professionalism. The Academy integrates the training related efforts of nuclear utilities, the independent National Nuclear Accrediting Board and the Institute’s training activities.
• RP mission statement: To consistently promote the highest standards in radiological safety. We identify gaps to excellence and provide assistance to foster continuous improvement.
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Transformation 1980-1990
• Organizational Changes• Increased Staffing and Resources• Improved Technology• Performance-based• Stop-Work Authority• ALARA• Accredited Training• Problem Identification and Resolution
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No. of Operating Power Reactors1969-1990
1970 1975 1980 1985 19900
20
40
60
80
100
120
LWRPWRBWR
19
Average Collective Radiation Dose Per Reactor (Person-Sv) 1969-1990
1970 1975 1980 1985 19900
2
4
6
8
10
12
LWRPWRBWR
20
Average Measurable Dose per Worker (mSv/a) 1969-1990
1970 1975 1980 1985 19900
2
4
6
8
10
12
LWRPWRBWR
21
Individual Annual Dose Distribution (mSv/a) 1973-1990Per Cent of Monitored Workers with Measurable Dose
1975 1980 1985 19900
5
10
15
20
25
30
35
40
>10>20>50
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1991 - Present
OccupationalDose Limit:5 rem TEDE50 rem CDE15 rem LDE50 SDE
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HP Science – Discrete Radioactive Particles (DRP)
• Microscopic, high specific activity particles containing Co-60 or fission products
• Become electronically charged as a result of radioactive decay –highly mobile
• On the skin, DRPs can expose small amounts of tissue to relatively high, localized doses
• Potential biological effects include reddening or transient breaks in the skin
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DRP Impacts• Issue emerged in the late 80’s with use of more
sensitive portal monitors• Some exposures exceeded the NRC SDE limit,
when applying existing skin dose criteria and standards -enforcement and limitation of worker access
• Extraordinary measures were implemented to prevent regulatory overexposures
• Impacts not commensurate with actual health detriment
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Discrete Particle Impact Refueling Floor Controls: Pre-Industry Focus Refueling Floor Controls: Post-Industry Focus
Single Cotton PC’s Specialized training for RP & radworker
Single step off pad (SOP) Increased signage & designated “Discrete Particle” zone with double SOP’s
Hand frisk (self-performed) RP Tech performs initial survey on worker
Exist RCA via portals PC’s removed with RP support
RP Tech performs second survey
“Sticky” pads used as SOP’s and “sticky” rollers for decontamination (masslin not as effective)
Localized ventilation & downdraft equipment used
RWP approval by senior manager required
Increased survey frequency of the area required
Use of respirators increased
Double PC’s and “plastics” worn. Entire PC program evaluated
Significant increase in industrial safety concerns (heat stress, limited vision, etc.)
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DRPEveryone Stepped Up
• INPO summarized industry experience and recommended best practices to control and minimize exposures
• NCRP published Report No. 106 estimating negligible stochastic health effects from DRPs
• NRC funded Brookhaven (BNL) to study health effects and develop guidance –demonstrated through pig-skin studies that DRPs do not pose any serious health detriment
• EPRI did collaborative research that confirmed BNL conclusions regarding negligible health detriment
• NCRP issued Report No. 130 including a dose-limiting guideline of 50 rads averaged over 10 square centimeters.
• NRC issued a policy statement on discretionary enforcement for DRP exposures until a new rule was issued
• NRC issued a final rule in incorporating the use of averaging exposure over 10 square centimeters for SDE
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Insights• Implementation of new technologies or methods
may produce unanticipated outcomes • Controlled-restricted areas, TEDE-ALARA, Alarming
Dosimeters and Centralized Remote Monitoring are additional examples
• These are change management issues and often need specific orientation or training for all affected parties and an effective communication plan
• Pilot programs, table tops and pre-implementation walkthroughs are useful
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No. of Operating Power Reactors1969-2014
1970 1975 1980 1985 1990 1995 2000 2005 20100
20
40
60
80
100
120
LWRPWRBWR
29
Average Collective Radiation Dose Per Reactor (Person-Sv) 1969-2013
1970 1975 1980 1985 1990 1995 2000 2005 20100
2
4
6
8
10
12
LWRPWRBWR
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Average Measurable Dose per Worker (mSv/a) 1969-2011
1970 1975 1980 1985 1990 1995 2000 2005 20100
2
4
6
8
10
12
LWRPWRBWR
31
Individual Annual Dose Distribution (mSv/a) 1973-2011Per Cent of Monitored Workers with Measurable Dose
1975 1980 1985 1990 1995 2000 2005 20100
5
10
15
20
25
30
35
40
>10>20>50
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Fukushima
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Fukushima
• Facilitated full engagement of the US nuclear power HP community with the international HP community
• More useful exchange than expected, despite cultural and governmental differences
• Expanded existing information exchange and benchmarking opportunities
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Occupational Radiation Protection in Severe Accident Management:
Sharing Practices and ExperiencesCo-sponsored by OECD Nuclear Energy Agency (NEA) and International Atomic Energy Agency (IAEA)
Hosted by the Nuclear Energy Institute (NEI)
Washington DC, USA 17-18 June 2014
Continuous Learning Opportunities
• HPS Powernet• HPS Power Reactor Sessions• INPO Operating Experience Network• INPO Workshops• EPRI Research Projects and Workshops• NEI Radiation Protection Forum• ISOE Network and Workshops• And many others
36
Looking Ahead
• Major Revisions to NRC Regulations• Source Term Reduction• Focus on RP Fundamentals • Focus on Specialized Workers and Tasks• Workforce
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Revisions to Regulations – Knowledge Transfer and Retention Opportunity
• USEPA 40 CFR 190
• USNRC 10 CFR 20
• USNRC Appendix I to 10 CFR 50
• And many, many USNRC regulatory guides
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Source Term ReductionWhere the Dose Comes From
• Reduce cobalt inventory• Improve water chemistry control and filtration• Eliminate hot spots• Reduce number of high radiation areas• Install permanent shielding• Maintain excellent fuel performance
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RP Fundamentals
“It’s not about stopping the work when you think that something is wrong. It’s about stopping the work when you don’t know that everything is right.”
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Focus on Specialized Workers & TasksWhere the Dose Is
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Nuclear Industry Employment Distribution by Age
0%
5%
10%
15%
20%
25%
30%
18-22 23-27 28-32 33-37 38-42 43-47 48-52 53-57 58-62 63-67
Empl
oyee
s
Age Range
2003
2005
2007
2009
2011
2013
Source: 2013 NEI Pipeline Survey Results, Contractors and vendors not included
Total Employment:
2013–62,170
2011 - 59,700
2009 - 57,200
2007 - 55,900
2005 - 57,900
2003 - 58,400
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Some Closing Thoughts• Remind yourself from time to time why you got into Health
Physics –it helps to refocus• Radiation protection is much about culture, communication
and trust –not just dose• Learn from experience -it is always possible to do better the
next time and the next tine and the next time• Change is often desirable and sometimes necessary –but think
about and plan for unintended consequences• Reach out broadly for peer information exchange and
networking –it actually does “take a village…”• Set the best possible example for the next generation
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Thanks for the Memories
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Acknowledgements
• Ellen Anderson, Jerry Hiatt, Jim Slider and Janet Schlueter at NEI
• Roger Pedersen at NRC• Roger Shaw at Shaw and Associates• Inid Deneau at Landauer • Nuclear Suppliers Association• All dose data from NRC NUREG 0713 series• And many others
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