Resolution of Generic Safety Issues: Task III.D.3: Worker Radiation Protection Improvement (Rev. 3) ( NUREG-0933, Main Report with Supplements 1–35 )
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The objective of this task is to improve nuclear power plant worker radiation protection to allow workers to take effective action to control the course and consequences of an accident, as well as to keep exposures as low as reasonably achievable (ALARA) during normal operation and accidents, by improving radiation protection plans, health physics, inplant radiation monitoring, control room habitability, and radiation worker exposure data base.
ITEM III.D.3.1: RADIATION PROTECTION PLANS
DESCRIPTION
Historical Background
The purpose of this TMI Action Plan48 item is to improve nuclear power plant worker radiation protection programs by better defining the criteria and responsibility for such programs. Detailed appraisals of health physics programs at all operating nuclear power plants were performed in 1980 and 1981. These appraisals, summarized in NUREG-0855,204 indicated that certain generic deficiencies existed at many plants due in part to lack of specific performance criteria and/or assigned responsibility for programs. The establishment of a radiation protection plan as a guiding document for implementing procedures has been proposed as a method for formalizing commitment to specific performance criteria contained in Regulatory Guides and SRP Section 12.11 Proposed guidance and acceptance criteria for radiation protection plans have been published in draft form as NUREG-0761.205 A proposed amendment to 10 CFR 50 has been drafted.206
Safety Significance
The development of radiation protection plans has no impact on public safety. Instead, the safety significance lies in the reduction of occupational exposure.
Possible Solutions
As currently envisioned, radiation protection plans would tie together specific implementing procedures, many of which currently exist at licensed plants. Additional procedures may be required at many plants to fully implement the plan; however, extensive revision of procedures should not generally be required. Administrative and technical manpower would be required to develop the plan, revise and write procedures as necessary, and some additional equipment (such as additional survey equipment) may be required. Installation of such equipment should not require any significant work in radiation areas. The benefit of radiation protection plans would be in two primary areas: (1) reduction of individual and collective dose due to improved planning and controls for work in radiation areas, and (2) improved confidence in results of radiation protection programs.
PRIORITY DETERMINATION
The assessment of this issue and its resolution was first performed64 by consensus opinions of four PNL health physicists who were extensively involved in the Health Physics Appraisal Program. These personnel included expertise from both industry and regulatory sides of the issue. Estimates of routine cost and probable man-rem reductions were discussed and agreed upon. For core-melt accident recovery and refurbishing, the panel assumed man-rem savings comparable on a percentage basis to those for routine operations. The cost impact of these man-rem savings was then estimated by a PNL expert involved in estimating accident recovery costs.
Frequency/Consequence Estimate
There are three terms in the estimation of occupational dose change due to this safety issue. These are the change due to accidents, the change due to issue resolution implementation, and the change due to resolution operation.
The estimated change due to accidents (the first term) is the change in the product of accident frequency and occupational dose associated with the recovery from an accident. As previously stated, no change in accident frequency is expected to occur due to this issue. However, a small change in occupational accident recovery dose is expected. Radiation protection plans are primarily oriented toward routine plant operation. In the event of a major core-melt accident, specialized procedures would have to be developed. Having the upgraded radiation protection plan for normal operation in place, however, is expected to result in improved specialized procedures if required. The resulting reduction in occupational dose for plant recovery is estimated to be slightly less than 5%. Using the estimates of total occupational dose resulting from recovery from an accident, as listed in Appendix D of NUREG/CR-2800,64 this works out to 3.3 x 10-2 man-rem/RY for BWRs and 7.4 x 10-2 man-rem/RY for PWRs.
The implementation of radiation protection plans (the second term) would be an administrative effort. Therefore, there is zero exposure associated with implementation.
The establishment of radiation protection plans is estimated to result in a reduction of occupational risk during operation (the third term). This reduction would be due to improved controls on personnel dose and an improved ALARA Program. PNL's experts estimated the occupational dose reduction to be on the order of 5%.64 However, the Occupational Radiation Protection Branch (ORPBR) of RES has been investigating the costs and benefits associated with radiation protection plans. Based on a comparison of plants with and without major radiation protection plans, it was estimated that occupational doses could be reduced by at least 10%. Savings of 25% or more appear achievable.207 The 1980 average occupational dose was about 800 man-rem. Therefore, we will assume that radiation protection plans could avert 200 man-rem/RY.
Cost Estimate
PNL estimated that 35 man-weeks at a cost of $35,000 and equipment worth $50,000 would be required per plant to implement the radiation protection plans.64 In order to operate under the new radiation protection plans, it was felt that most plants would have to add personnel. It was estimated that one professional and one technical staff member would be needed. At 52 weeks per year, this gives an additional 104 man-weeks per year for each plant, or $104,000 plant cost per year.
However, ORPBR has noted that the licensees' cost will vary widely depending on the adequacy of the present program.206 In addition, since radiation protection plans have the effect of reducing the time workers are exposed, individual tasks are often speeded up. Some licensees have found that the savings resulting from reduced downtime have compensated for the cost of the program.
Currently, there are 43 operating PWRs with a cumulative experience of 350 RY and 27 BWRs with a cumulative experience of 260 RY. If we add to these the 36 PWRs and 21 BWRs under construction and assume a plant lifetime of 30 years, there are 3,200 RY remaining: 1,180 RY for BWRs and 2,020 RY for PWRs.
ORPBR has estimated that 5 NRC staff-years will be required.206 Thus, NRC costs are estimated to be $500,000.
The total cost associated with the solution to this issue is $340.5M.
Value/Impact Assessment
The total risk reduction associated with this issue is 6.4 x 105 man-rem. Therefore, the value/impact score is given by:
Uncertainties
The dominant parameters in the evaluation of this issue are the percent saving in occupational dose during normal operation, which is unlikely to be incorrect by more than a factor of ten, and the cost to the licensee, which is expected to be within a factor of 5. This implies a range in S from 100 to 30,000 man-rem/$M and a range in total man-rem saved of 6 x 104 to 6 x 106.
CONCLUSION
Based on the value/impact score and potential reduction in occupational dose, this issue was give a high priority ranking. In resolving this issue, the staff agreed to support alternative regulatory concepts which recognize the contributions of industry self-policing programs to the extent that such programs are effective and consistent with NRC regulatory responsibilities. As a result, the staff entered into a "Coordination Plan for Radiological Protection Activities" with INPO under a "Memorandum of Agreement Between INPO and the USNRC." Under this agreement, over the two-year period outlined in the Coordination Plan, NRR staff developed a method for evaluating industry performance in radiation protection programs incorporating ALARA concepts at power reactors and observed the INPO evaluation and assistance process at a number of operating facilities.
The staff performed analyses of a number of radiological data trends as part of the effort to determine if the power reactor industry has achieved successful ALARA-integrated radiation protection programs. An analysis of these trends and portions of the supporting data bases were documented in the report, "Summary Analysis of Selected Radiological Trends at Power Reactors."912
Following the staff's compilation of data and evaluation of a number of trends in radiological protection at power reactors, the staff concluded that most power reactor radiation protection programs are adequately incorporating ALARA concepts and can satisfactorily perform at a level which meets the objectives of Item III.D.3.1 Thus, this issue was RESOLVED and no new requirements were established.913
ITEM III.D.3.2: HEALTH PHYSICS IMPROVEMENTS
The four parts of this item have been combined and evaluated together.
DESCRIPTION
Historical Background
In this TMI Action Plan48 item, four specific items were identified for resolution: (1) Requirement for Use of Certified Personnel Dosimeter Processors; (2) Audible Alarm Dosimeter Regulatory Guide; (3) Develop Standard Performance Criteria for Radiation Survey and Monitoring Instruments; and (4) Develop Air Purifying Respirator Radioiodine Cartridge Testing and Certification Criteria. Item (2) will not be considered further since Regulatory Guide 8.28 was issued in final form prior to this evaluation. Thus, Item (2) is considered resolved.
Safety Significance
(1) Requirement for Use of Certified Personnel Dosimetry Processors.
The proposed resolution would amend 10 CFR 20 to require that only nationally certified dosimetry processors be used by NRC licensees for personnel radiation dosimetry. Processors would be required to meet ANSI N13.11 (or its replacement standard) criteria for testing. Certification of processors would be performed by the National Voluntary Laboratory Accreditation Program (NVLAP) administered under the auspices of the U.S. Department of Commerce (DOC).
This issue does not specifically address core-melt accidents nor the public risk, occupational dose, or accident avoidance costs associated with such accidents. It is related to the worker's right to accurate measurements of occupational dose. The proposed resolution would require accurate and precise determinations of individual worker doses using dosimeters, readout systems, and processing procedures certified to be capable of meeting minimum criteria defined in a national standard. The administrative and regulatory limits for occupational dose would be unaffected by this work.
A draft ANSI standard (ANSI N13.11) for dosimeter testing was issued for trial use in 1978. This standard has undergone substantial testing and remains only to be finalized for issuance as a new ANSI standard. Once issued, it will form the basis for amending 10 CFR 20. Testing and certification of dosimeter processors for criteria contained in this standard will be performed by NVLAP under DOC.
(2) This item has been resolved as discussed before.
(3) Develop Standard Performance Criteria for Radiation Survey and Monitoring Instruments
Testing of radiation survey and monitoring instruments will provide a high degree of quality assurance that instruments are capable of performing intended functions under specified conditions. This will allow consistent utilization of workers without impacting current individual or collective occupational dose. A draft standard for health physics instrumentation testing (ANSI N42.17-D2) has been developed.
This standard will undergo a field trial period, using off-the-shelf instruments, to determine its adequacy. This trial period is presently estimated to continue through FY-1984 and is jointly funded by NRC and the Department of Energy (DOE) at $400,000 each. Following the trial period, a final standard will be adopted by NRC and only those instruments meeting this standard would be acceptable for use in NRC licensed facilities.
At this time, a plan for implementing the testing program has not been developed. It is anticipated, however, that independent testing laboratories would, for a fee, test instruments submitted by vendors or reactor licensees.
The testing laboratories would be certified by NVLAP under DOC. Costs associated with NVLAP certification and instrument testing fees would be passed on to industry in the form of higher instrument prices.
(4) Develop Air Purifying Respirator Radioiodine Cartridge Testing and Certification Criteria
Air purifying respirators are not currently acceptable for radioiodine protection due to the lack of accepted test procedures for certifying cartridge filtering efficiency. The result is that bulky self-contained breathing apparatus (SCBA) must be worn by workers in radioiodine environments. Such environments are expected during and after core-melt accidents. The results of wearing SCBA is to substantially reduce worker efficiency due to physical stress and the relatively short working time limited by air tank capacity. Use of air purifying respirators would reduce worker stress and improve worker efficiency.
It is expected that operator dose would be unaffected by the availability of respirators. Immediately after an accident, SCBA would still be used due to immediate hazards. During long-term recovery activities respirators could be used. However, reduced external dose due to efficient use of time
in radiation zones is expected to be offset by the reduced effectiveness of the respirators, compared to SCBA, in avoiding internal exposures. Criteria and test procedures for radioiodine cartridges have been under development by LASL using NRC funds. The technology has been developed and is in the process of being transferred to NIOSH. When transfer is complete, it is anticipated that NIOSH will amend 30 CFR 11 to incorporate the testing methods and criteria into respirator test and certification schedules. Respirator and cartridge manufacturers would submit products for certification testing and periodic quality control checks would be performed.
Following establishment of certification programs, NRC evaluation is anticipated regarding the need to specify the quantity and types of respirators necessary for normal and emergency use at a typical power reactor.
This issue will have no impact on public risk associated with core-melt accidents. The occupational dose impact is also considered to be zero, the benefit to workers being reduced stress, improved comfort and, consequently, better worker performance.
CONCLUSION
The above issues and their proposed resolutions do not impact public risk nor are they expected to increase or decrease occupational dose. They relate to the rights of workers to be assured of adequate radiation protection and would reduce stress during the performance of work in radiation zones. Therefore, this item is considered to be a Licensing Issue. The disposition of the four parts of this item is listed below.
ITEM III.D.3.2(1): AMEND 10 CFR 20
This Licensing Issue was evaluated in Item III.D.3.2 and was later resolved in February 1987 with the publication of a final rule on the requirement for the use of NBS-accredited personnel dosimetry processors.1046
ITEM III.D.3.2(2): ISSUE A REGULATORY GUIDE
This Licensing Issue was evaluated in Item III.D.3.2 above and was determined to be resolved.
ITEM III.D.3.2(3): DEVELOP STANDARD PERFORMANCE CRITERIA
The NRC/DOE project has produced several procedure manuals for future performance testing of radiation survey instruments and airborne radioactivity monitoring systems, after a certification program is established. These manuals are based on laboratory tests of sample instruments and monitoring systems using a draft of ANSI 42.17, "Performance Specifications for Health Physics Instrumentation." The IEEE Standard development working group is now using the results of the NRC/DOE project to finalize the standard for use in the accreditation program.
No further NRC action will be taken unless the instrument manufacturing industry fails to establish a satisfactory certification program within a reasonable period of time following final publication of ANSI 42.17. The final draft of this standard is under review by ANSI participants; some manufacturers' concerns still need to be resolved.
The NRC staff has taken the position that the industry should establish its own certification program and that the NRC would intervene only if the industry failed to do so, or if its program proved to be unsatisfactory. Thus, this Licensing Issue has been resolved.954
Item III.D.3.2(4): Develop Method For Testing and Certifying Air-Purifying Respirators
A research project has been completed that provides experimental data and recommendations for establishing a standard test procedure and acceptance criteria for air purifying respirator cartridges and canisters used to protect workers, and simultaneously measure penetrations of radioiodine and normal iodine vapor species through beds of various charcoals. The effects of various conditions of use (bed depth, contact time, concentration, relative humidity, temperature, flowrate, and flow cycling) were studied to identify testing requirements. Recommendations for testing and approval were based on consideration of the effects of these parameters. An apparatus designed and built for testing has been delivered to NIOSH, the responsible institute for testing and certifying respiratory protection equipment. Such certification is required in 10 CFR Part 20. In 1983, the staff published NUREG/CR-3403.969
NIOSH certification is now available. Licensees who wish to take credit for such equipment may do so after obtaining individual authorization from NRC. Thus, this Licensing Issue has been resolved.954
ITEM III.D.3.3: IN-PLANT RADIATION MONITORING
The four parts of this item are listed separately below.
ITEM III.D.3.3(1): ISSUE LETTER REQUIRING IMPROVED RADIATION SAMPLING INSTRUMENTATION
This item was clarified in NUREG-0737,98 requirements were issued, and MPA F-69 was established by DL for implementation purposes.
ITEM III.D.3.3(2): SET CRITERIA REQUIRING LICENSEES TO EVALUATE NEED FOR ADDITIONAL SURVEY EQUIPMENT
DESCRIPTION
This NUREG-066048 item required NRR to set criteria requiring licensees to evaluate in their plants the need for additional survey equipment and radiation monitors in vital areas and requiring, as necessary, installation of area monitors with remote readout. NRR was to evaluate the need to specify the minimum types and quantities of portable monitoring instrumentation, including very high dose rate survey instruments. Operating reactors were to be reviewed for conformance with SRP11 Section 12.3.4, "Area Radiation and Airborne Radioactivity Monitoring Instrumentation." NRR was to revise SRP Sections 12.5 and 12.3.4 to incorporate additional monitor requirement criteria.
CONCLUSION
In December 1980, the requirements for high range area and portable monitors were incorporated into Regulatory Guide 1.97, Revision 2. In July 1981, SRP11 Sections 12.3 and 12.5 were revised to incorporate the requirements for in-plant radiation monitoring. Thus, this item was RESOLVED and new requirements were established.
ITEM III.D.3.3(3): ISSUE A RULE CHANGE PROVIDING ACCEPTABLE METHODS FOR CALIBRATION OF RADIATION-MONITORING INSTRUMENTS
DESCRIPTION
This NUREG-066048 item required RES to issue a rule change providing acceptable methods for calibration of radiation-monitoring instruments.
CONCLUSION
The required change was covered in the overall revision to 10 CFR 20, Paragraph 20.501(c). Thus, this item was RESOLVED and new requirements were established.
ITEM III.D.3.3(4): ISSUE A REGULATORY GUIDE
DESCRIPTION
This NUREG-066048 item required RES to issue a Regulatory Guide providing acceptable methods for calibration of air-sampling instruments.
CONCLUSION
Regulatory Guide 8.25 was issued in August 1980. Thus, this item was RESOLVED and new requirements were established.
ITEM III.D.3.4: CONTROL ROOM HABITABILITY
This item was clarified in NUREG-0737,98 requirements were issued, and MPA F-70 was established by DL for implementation purposes.
ITEM III.D.3.5: RADIATION WORKER EXPOSURE
The three parts of this item have been combined and evaluated together.
DESCRIPTION
This TMI Action Plan48 item called for the NRC to continue its efforts to improve and expand the data base on industry employees in order to facilitate possible future epidemiological studies on worker health. The three parts of this item are as follows:
| (1) | "Improve and expand the data base on industry employees." This item is considered important in improving a data base used by the NRC in judging the adequacy of its radiation protection standards. Meetings have been held with DOE, ORM, NCI, AIF, and officials of Canadian and British national dose registries and health statistics organizations to discuss issues related to this item. Although these meetings have resolved certain generic issues, this item is a long-term goal requiring on-going cooperation between nuclear regulators, industries, and workers.409 |
| (2) | "Investigate non-legislative means of obtaining employee health data." This item was completed in September 1982 following discussions about worker health data with DOE, AIF, EPRI, and officials of British and Canadian national dose registries and health statistics organizations.409 |
| (3) | "Include as part of the overall rewrite of 10 CFR Part 20 consideration of a requirement for licensees to collect worker medical data." This item was completed in February 1981 following a decision by the Part 20 task force not to require the collection of worker medical data.409 |
The value of this item does not lie in the reduction of public or occupational risk. Instead, it will provide data on which future regulatory decisions will be based. Therefore, this item is not directly related to public safety and is considered a licensing issue.
CONCLUSION
The disposition of the three parts of this Licensing Issue is listed below.
ITEM III.D.3.5(1): DEVELOP FORMAT FOR DATA TO BE COLLECTED BY UTILITIES REGARDING TOTAL RADIATION EXPOSURE TO WORKERS
10 CFR 20.408 requires utilities that operate nuclear power plants to submit to the NRC a report that provides identification and exposure information for each monitored individual at the time of completion of the individual's assignment or employment at a particular plant. In order to improve the processing of this worker dose data, the NRC staff developed NRC Form 439, "Report of Terminating Individual's Occupational Exposure." This new form improved and expanded the dose data base that would be needed to support possible future epidemiological studies. The NRC staff, in cooperation with HHS, plans to recommend that the Committee for Interagency Radiation Research Policy Coordination (CIRRPC) review the issue of a worker registry and epidemiologic studies and formulate recommendations. The staff concluded954 that the NRC does not have the authority or the resources to support a worker registry or epidemiological health effects studies. Thus, this Licensing Issue has been resolved.
ITEM III.D.3.5(2): INVESTIGATIVE METHODS OF OBTAINING EMPLOYEE HEALTH DATA BY NON-LEGISLATIVE MEANS
This Licensing Issue was evaluated in Item III.D.3.5 above and was determined to be resolved.
ITEM III.D.3.5(3): REVISE 10 CFR 20
This Licensing Issue was evaluated in Item III.D.3.5 above and was determined to be resolved.
REFERENCES
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