ML20024B723
| ML20024B723 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 07/07/1983 |
| From: | Dempsey K, Fairobent J, Jeffrey Mitchell Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20024B704 | List: |
| References | |
| NUDOCS 8307110279 | |
| Download: ML20024B723 (13) | |
Text
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4 11.
UNITED STATES OF AMERICA
- NUCLEAR REGULATORY COPMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of DUKE POWER COMPANY, ET AL.
Docket Nos. 50-413 50-414 (CatawbaNuclearStation.
Units 1 and 2)
AFFIDAVIT OF JOCELYN A. MITCHELL, KENNETH C. DEMPSEY, AND JAMES E. FAIR 0 BENT IN SUPPORT OF
SUMMARY
Disp 0SITION OF DES CONTENTION 17 1.
I, Jocelyn A. Mitchell being duly sworn, do depose and state:
I am an employee of the U.S. Nuclear Regulatory Comission. My present position is Nuclear Engineer Accident Evaluation Branch of the Division of Systems Integration in the Office of Nuclear Reactor Regulation.
I am responsible for the analysis of t.ccidents for safety and environmental reviews, and have coordinated the environmental review P
of accidents for. the Catawba plant. My professional and education qualifications are attached to this statement.
I certify that I have personal knowledge of the matters set forth herein with respect to the above areas for which I am responsible, and that the statements made are true and correct to the best of my knowledge.
- 2..
I, Kenneth C. Dempsey, being duly sworn, do depose and state:
I am a Nuclear Engineer, Accident Evaluation Branch, Division of Systems Integration within the Office of Nuclear Reactor Regulation. My
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responsibilities include the review and evaluation of Safety Analysis 830711o279 83070s PDR ADDCK 05000413 O*
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Reports and Environmental Reports relative to accident mechanisms and 1
dose calculat%ns. A copy of my professional qualifications is attached.
1 I certify that I have personal knowledge of the matters set forth herein i
with respect to the above areas for which I am responsible, and that the statement > inade are true and correct to the best of my knowledge.
3.
I, James E. Fairobent, being sworn, do depose and state:
I am an employee of the U.S. Nuclear Regulatory Conmission (NRC). My present position is Meteorologist, Meteorology and Effluent Treatment Branch, Division of Systems Integration within the Office of Nuclear Reactor Regulation. My responsibilities include the evaluation of meteorological data used in the Staff's environmental reviews of accidents. I certify that I have personal knowledge of the matters set forth herein with respect to the above areas for which I am responsibic and that the state-ments made are true and correct to the best of my knowledge.
4.
This affidavit addresses DES Contention 17, which reads as l
follows:
The DES is concerned with environmental impacts. Presumably these are best represented as the entire range from trivial to serious, in conjunction with the estimates of likelihood. The DES averages meteorological conditions in its consideration of accidents, 5.9.4.5.
Because atmospheric inversions and quiet air are a very comon feature in this region, accident consequences should be calculated for the extreme condition of inversion and very slow air movement.
In the matter of assessing serious accidents, the environmental assumptions are complex and again do not appear to consider extreme weather, p. 5-37. The DES, which differs from the CP FES in considering severe accidents, is at fault in not considering the l
full range of radiological impacts by not considering extreme, but frequently encountered, weather conditions.
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5.
Tliis contention is in two parts:
Itassertsthat(1)the Staff's environmental impact statement (EIS) should calculate the consequences of design basis accients based on "the extreme condition of inversion and very slow air movement," and (2) the Staff's EIS should 1
consider " extreme, but frequently encountered, weather conditions" in its consideration of the radiological impacts of severe (beyond design hasis) accidents.
6.
The Staff's environmental reviews in connection with its environmental impact statements have been perfonned to comply with the following authorities, the National Environmental Policy Act of 1969, as amended (NEPA), and, second, the Comission's own implementing regula-tions and policy guidance. Section102(2)(C)(1)requiresagencies,"to the fullest extent possible," to explore the environmental effects of proposed actions. The Staff interprets this requirement to require a I
reasonably thorough discussion of environmental consequences, but not to require discussion of remote or highly speculative consequences. Part 51 of NRC regulations requires preparation of an environmental impact statement, and an EIS for an operating license application must address " matters which differ from, or which reflect new infomation in addition to, those matters discussed in the final environmental impact statement prepared in connection with the issuance of the construction pern;it." Section51.23(e). Finally, in implementing the NEPA mandate for an EIS, the Comission requires the Staff EIS to include " reasoned consideration of environmental risks (impacts) attributable to accidents" giving equal attention "to the probability of occurrence of releases and n.- -
to the probability of occurrence of the environnental consequences of those releases." Statement of Interim Pc' gy. 45 Fed. Reg. 40101, June 13, 1980.
7.
Inasmuch as DES Contention 17 specifically challenges the adequacyoftheStaff'sconsiderationofmeteorology(" weather")inits accident analysis, the affidavit explains the manner in which the Staff's consideration of meteorological conditions, with respect to both design basis and severe accidents, is " reasonably thorough," and with specific reference to the Commissions' Policy Statement on severe accidents, how the Staff's meteorological assumptions permit a reasoned consideration of the probability of the occurrence of environment consequences.
8.
In the Catawba FES, the meteorological environment at the site was considered in three different ways, reflecting the use to which each type of calculation is put. The meteorological data on which each evaluation is based are considered representative of the frequency of occurrence of stable atmospheric oispersion conditions accompanied by low wind speeds (referred to in the contention as " atmospheric inversions and quiet air").
9.
The Final Environmental Statement discussed two analyses of theconsequencesofpostulateddesignbasisaccidents(identifiedin Table 5.9), one analysis used " average" meteorological conditions, the other "very poor" meteorology. The first analysis used " average"U conditions to arrive at " realistic" doses (FES, p. 5-35, Table 5.9);
the second analysis used very poor meteorological assumptions, in order
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Meteorological conditions were assumed that produce calculated doses that would not be expected to be exceeded more than 50% of the time because of other meteorological conditions at the site.
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to obtain conservative estimates of individual exposures from design basis accidents.
(FES,p.5-35).
- 10. The latter analysis is being performed for the Staff's safety evaluation to assure that the doses to any individual at the exclusion area boundary (EAB) (over a period of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />) will not exceed 25 rems to the whole body, or 300 rems to the thyroid, pursuant to 10 CFR Part 100, and uses the atmospheric dispersion model described in Regulatory Guide 1.145. -This safety evaluation is used to examine site suitability and the mitigative capability of the plant safety features. The atmospheric dispersion model for this evaluation uses onsite meteorological data considered representative of the site and vicinity to calculate relative concentrations (X/Q) values which will be exceeded no more than 0.5% of the time in any one sector (221*) and no more than 5% of the time for all sectors (360 ) at the EAB. Similar calculations are made at the outer boundary of the LPZ. Accidental releases through building vents and penetrations are assumed to be at ground-level for this evaluation.
For ground-level releases, the highest X/Q values are produced for stable atmospheric conditions (Pasquill types "E", "F", and "G") accompanied by low wind speeds. The combination of these conditions occurs quite frequently at Catawba. This relatively high frequency is reflected in the-two years (December 17, 1975 through December 16,1977) of onsite data considered for the evaluation of DBA's. By calculating X/Q values which are large enough to be exceeded only infrequently at the site and by_using meteorolcgical data with a high frequency of stable conditions accompanied by low wind speeds, the safety calculation of doses from DBA releases, therefore, considers " extreme, but frequently encountered, weather conditions."
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- 11. While the foregoing analysis is performed for purposes of the Staff safety evaluation, it was nevertheless considered in the FES as I
providing an upper bound for off-site doses for design basis accidents using conservative meteorological assumptions.
- 12. The same postulated design basis accidents were also, as noted, analyzed in the FES using " average" meteorological condition in I
order to obtain " realistic" doses. The values obtained, as shown in Table 5.9, reflect the average meteorological conditions used, and are much lower than the values shown in the very conservative safety analysis. Nevertheless, because the realistic dose calculations use representative'onsite meteorological data, these analyses include the relatively high frequency of stable atmospheric conditions accompanied by low wind speeds.
- 13. The Staff, therefore, considers both average and very poor meteorological conditions in order to obtain " realistic" and very conservative consequences for postulated design basis accidents.
In this manner, the Staff includes both the most expected, and the bounding valu'es produced by weather considerations. This treatment fully satisfies the requirement of providing a reasonably thorough discussion of environmental impacts under NEPA.
14.
In the Staff's evaluation of severe accidents, shown at Section 5.9.4.5(2) of the FES, the meteorological conditions at the site are taken into account in an entirely different manner from that used in either the safety analyses of DBA's or the realistic analyses.
In the j
severe accident analyses, hour by hour data from the site (representing a full year's worth of data) are used in assessing propagation of the l
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plume of radioactive material from the time of release to the time the plume reaches the end of the last spatial interval. Ninety-one different start times are used and from about 10 to 200 consecutive hours of data are required to evaluate plume transport (Section 7, Appendix VI, WASH-1400) for each start time.
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- 15. The authors of WASH-1400 evaluated various sampling strategies for the meteorological data. This evaluation is discussed in some detail in Section 13.2, Appendix XI of WASH-1400.
(Note that a statement in Section 13.2.1 is incorrect; the stratified sampling strategy was not four days plus one hour, but every four days on 13 hour1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> intervals). The authors concluded that the statistic of early fatalities is most sensitive to the number of samples, and that-sampling beyond 90 is not warranted because the statistics show that the differences are within the uncertainties of the consequence model. The statistics evaluated were not only the mean, which is the most important from the point of view of a reasoned consideration of risk, but also the variance and third and fourth moments. These latter statistics serve to f
describe the sufficiency of the sample to determine the " tail" or peak behavior of the probability density function. The Catawba FES in Tables 5.11, 5.12 and 5.13 contains information on the mean values of l
selected measures of risk (e.g., early and latent fatalities and costs) as well as impacts at selected probability levels, representing the probability density function.
- 16. Section 5.9.4.5(7) of the Catawba FES discusses the uncertainties in the assessment of severe accidents. Specifically discussed in this section is the atmospheric dispersion model. This
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. discussion indicates that an improved meteorological sampling scheme i
would reduce variability due to that source, but that important uncertainties would still remain in the meteorological model. These include particle size distribution and chemical form of the radionuclides released, plume rise, and duration of the release. The staff judgment is presented in that same section that the risk results are a reasonable analysis and that the uncertainty bounds would likely be over a factor of 10, but not so large as a factor of 100.
- 17. The Staff's consideration of meteorologica, conditions in the evaluation of environmental impacts of severe accidents is thus
" reasoned" and " thorough" and fully implements the Comission's Policy Statement to give " equal attention to the probability of occurrence of the environmental consequences of... releases" in consideration of environmental risk (impacts). 45 Fed. Reg. 40101.
- 18. The Staff's consideration of meteorological conditions is thus shown to be appropriate for both design basis and severe accidents evaluations. If the Staff were to have relied principally or solely upon " worst-case" meteorological conditions, whether due to atmosphere inversionsorsomeotherpostulatedsetofatmosphericconditions(such as those " extreme" conditions suggested by Intervenors in their responses to discovery), in the environmental impact evaluations of severe accidents, inappropriate weight would have been given to remote or speculative consequences, which would have distorted the reasoned l
consideration of risks. That the Staff's consideration of both design basis and severe accidents is both " reasoned" and " thorough" can also be seen when one considers the purpose of the calculations and assumptions used by.the Staff in DBA and severe accident evaluations as described above.
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- 19. The " realistic" doses are presented in the FES to demonstrate the doses th.tt may be expected in the event of design basis accidents.
They are not intended to incorporate extreme elements of conservatism and average meteorology is appropriately assumed. The safety calculations used in the FES to establish bounding values of offsite doses are, as indicated earlier, intended to examine the mitigative capability of the facility as it affects site suitability and are conservatively based not only on the meteorological considerations, but also with respect to other parameters such as radioactive material content and release rate.
Overall conservatism is thereby maintained, but extreme values of each and every parameter is neither necessary nor desirable because this would represent a class of accidents with vanishingly small probability of occurrence, and no useful information concerning the mitigative features i
of the plant would be obtained.
- 20. With respect to the severe accider.t calculations in the FES, the actual meteorological conditions at the site are represented in the data' base. The choice of the sampling scheme, as discussed earlier, has been shcwn to be adequate to represent probability density functions of accident impacts. The probability range reported in the FES table of impacts is also sufficiently broad so as to provide a reasoned evaluation of risks.-
The uncertainties in the calculation of severe accident risks have been discussed. Therefore, the staff concludes that L
no additional meaningful information would be gained by a separate assessment of probability and consequences of extremely low likelihood events.
C4 c62/
Jotelyn A. Mitchell I
O.
M Kenneth C. Dempsey I
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Subscribed and sworn to before me this'1A* day of h & N 1983.
C IhWsr 7 IIlQ Notary Public My Commission Expires:
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JOCELYN A. MITCHELL PROFESSIONAL QUALIFICATIONS ACCIDENT EVALUATION BRANCH DIVISION OF SYSTEMS INTEGRATION I am employed as a nuclear engineer in the Accident Evaluation Branch, Division of Systems Integration U. S. Nuclear Regulatory Comission, Washington, D. C.
My duties include accident analyses for safety and environmental reviews, evaluation of extended burnup in power reactors as it impacts radiological consequences of accidents, and. evaluation of other safety-related studies for power and nonpewer reactor facilities.
In 1955. I joined the Westinghouse Electric Corporation at the Bettis Atomic Power Laboratory in West Mifflin, PA. During the time until 1980. I was involved in reactor physics evaluations of naval plants and the Shippingport Atomic Power Station. I was a reactor operator.
I also participated in safety reviews of critical facility operations, stcrage areas, feel shipments and manufacturing facilities as a member of various Safety Committees.
I was involved with the design, conduct, and evaluation of reactor physics experiments and cross section measurements.
I was the marager of a group which was responsible for the development of a nondestructive assay device for spent fuel rods and for the maintenance of an inactive critical facility.
I was the co-author of 16 technical publications covering physics measurements and calculations. These were published in Nuclear Science and Engineering, in the Bettis Technical Memoranda Series, or in the American Nuclear Society Transactions.
In 1980. I joined the Nuclear Regulatory Commission in the Reactor Safety Branch. During the few months before I joined the Accident Evaluation Branch, I was involved in the safety evaluation of nonpower i
reactor facilities.
In the Accident Evaluation Branch I have completed severe, accident assessments for Environmental Statements for seven l
sites.
I have also reviewed accident calculations for older piants as part of the Systematic Evaluation Program, and have reviewed license l
amendments for operating reactors.
t My fomal education consists of an A.B. degree in chemistry from Connecticut College.
In addition. I have taken post-graduate courses in chemistry at Carnegie Institute of Technology (presently Carnegie-Mellon University).
I have also studied Computer Science at the University of Pittsburgh and Nuclear Physics at the Bettis Reactor Engineering School.
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KENNETH C. DEMPSEY PROFESSIONAL QUALIFICATIONS OFFICE OF NUCLEAR REACTOR REGULATION.
U. S. NUCLEAR REGULATORY COMMISSION I am a Nuclear Engineer assigned to the Accident Evaluation Branch, Division of Systems Integration Office of Nuclear Reactor Regulation, U. S. Nuclear Regulatory Commission. My responsibilities include the review and evaluation of Safety Analysis Reports and Environmental Reports relative to accident mechanisms and dose calculations.
I have served in this capacity since May 1980 From 1976 to 1980, I worked for the U. S. Army Corps of Engineers where IheldpositionsasaNuclearEngineer(1976-1977) and a General
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Engineer (1977-1980). The work included development of designs, specifications, estimates, and performing engineering investigations and field engineering services. Estimating and evaluating radiation doses to the environment surrounding a nuclear power barge were also part of the duties.
Prior to working for the Corps of Engineers, I spent a year with the Singer Corporation, where I was a Systems Engineer in the design of l
Nuclear Power Plant Simulators.
i I have a Bachelor of Science degree with Honors in Nuclear Engineering from Lowell Technological Institute (1973) and I have had a year of
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graduate studies in Physics at the University of Maryland.
I am a member of Tau Epsilon Sigma and ASHRAE.
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I' James E. Fairobent Meteorology Section Meteorology and Effluent Treatment Branch
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Division of Systems Integration Office of Nuclear Reactor Reoulation Professional Qualifications 1 have been a Heteorologist with the Atomic Energy Commission, Directorate of Regulation, and subsequently the Nuclear Regulatory Comnission, Office
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of Nuclear Reactor Regulation, since February 1977.
I received a B.S. degree with a major in meteorology from the University While an undergraduate, I participated in a study of Michigan in 1970.
of precipitation scavenging by convective stoms which included field t
research programs in Oklahoma and Illinois. % responsibilities included maintenance of a precipitation collection network, analyses of mesoscale weather systems conducive of the formation of convective stoms, and neutron activation and radio-chemistry analyses of rainwater samples.
I entered the graduate program at the University of Nichigan in 1971, I and was awarded an M.S. degree with a major in meteorology in 1972.
continued my association with the precipitation scavenging project as a graduate student as well as becoming weather observer at the University of Michigan climatological station and a teachin9 fellow.
I accepted my present position in February 1973. I am responsible under the supervision of the Meteorology Section leader, for the evaluation of the meteorological characteristics of reactor sites and their implications with respect to safety requirements of nuclear facility Since design and the impact of these facilities on the environment.
1973, I have participated in the safety and envirornental. reviews of i
about 40 nuclear power plant sites.
I worked as a meteorologist for the National Comission on Air Quality from June 1979-March 1981 evaluating the Clean Air Act.
I returned to the NRC in March 1981 and resumed my former duties.
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I am a member of the American Meteorological Society, and the Ame Association for the Advancement of Science.
the Scientific Research Society of North America.
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