ML20052H011
| ML20052H011 | |
| Person / Time | |
|---|---|
| Site: | Clinch River |
| Issue date: | 04/30/1982 |
| From: | Mizuno G, Swanson D NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD) |
| To: | National Resources Defense Council, Sierra Club |
| Shared Package | |
| ML20052G984 | List: |
| References | |
| NUDOCS 8205190247 | |
| Download: ML20052H011 (18) | |
Text
4/30/82 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC AND SAFETY LICENSING BOARD In the Matter of
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U.S. DEPARTMENT OF ENERGY
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Docket No. 50-537 PROJECT MANAGEMENT CORPORATION
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TENNESSEE VALLEY AUTHORITY
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(Clinch River Breeder Reactor Plant)
NRC STAFF'S ANSWERS TO NATURAL RESOURCES DEFENSE COUNCIL, INC. AND THE SIERRA CLUB NINTH REQUEST TO STAFF FOR ADMISSIONS The Nuclear Regulatory Comission Staff (Staff) hereby responds to the Natural Resources Defense Council, Inc. (NRDC) and the Sierra Club Ninth Request to Staff for Admissions filed on March 18, 1982. Attached hereto are the Staff's answers to NRDC's and the Sierra Club's request for admissions. together with the affidavits of those individuals who preparedtheanswers.1/
In its April 14, 1982 Order Following Conference with Parties, the Licensing Board renumbered NRDC's contentions. When an old contention number appears in the request for admission or answer, the new contention number will be indicated in parentheses. At the April 20, 1982 Conference with parties, the Board withdrew discovery on Contentions 8a and 22, therefore, interrogatories #1 through #25 were not answered.
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The affidavits of Mr. Swift, Mr. Morris, Mr. Branagan and Mr. Bender are unsigned. Copies of their signed and notarized affidavits will be filed shortly.
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DR ADOCK 05000337 PDR
-2 Additionally, at the April 6, 1982 Prehearing Conference the Licensing Board withdrew discovery on Contention 23, therefore, inter-rogatories #1 and #2 in Section V pertaining to Contention 23 were not answered.
Respectfully submitted, f
Daniel T. Swanson Counsel for NRC Staff
.d Geary. Mizuno Counsel for NRC Staff Dated at Bethesda, Maryland this 30th day of April,1982 f
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NRC STAFF'S ANSWERS TO NRDC'S AND THE SIERRA CLUB'S REQUEST FOR ADMISSIONS I.
Contention 2 (renumbered as 1)
Statement 1 The assumed frequency of anticipated transient without scram (ATWS) accidents in LWRs in less than once in a thousand reactor years.
Response
The Staff neither admits nor denies the frequency of LWR ATWS events. Because of the uncertainty in ATWS frequency for LWRs and the possibility that this frequency may be close to once per thousand reactor years, the NRC has initiated rulemaking proceedings to either reduce the frequency of ATWS events or the consequences of ATWS events, or both (Federal Register, Vol. 96, No. 226).
Statement 2 The assumed frequency of anticipated transient without scram (ATWS) accidents in LWRs is on the order of once in a thousand reactor years.
Response
1 The response is identical to that for 1. above.
1 Statement 3 With LWRs, there have been several observed precursor events, i.e.,
faults detected that could have given rise to ATWS events.
Response
The Staff admits that such precursor events have been observed for LWRs (Federal Register, Vol. 46, No. 226).
Statement 4 The fact that there have been several observed precursor events that could have given rise to ATWS events suggests that the frequency of ATWS accidents, although less than once in a thousand reactor years, may not be very much less.
Response
The Staff admits to this for LWRs (Federal Register, Vol. 46, No.226).
Statement 5 There is insufficient actuarial experience with LMFBRs to reasonably indicate that the probability of an ATWS event in the CRBR is less than that in an LWR.
Response
The Staff neither admits nor denies this assertion. The existing acturial ATWS experience for LMFBRs and LWRs is not necessarily applicable to the determination of the probability of ATWS for CRBR.
Statement 6 It would be imprudent to assume for purposes of designing the CRBR to cope with accidents that the probability of an ATWS event in the CRBR is less than the probability of an ATWS event in an LWR.
Response
The Staff admits that such an assumption would be imprudent as a basis for design of CRBR and does not make it. The Staff will require in its safety review the acceptable implementation of a design including highly reliable redundant, independent, and diverse shutdown systems to assure that the probability ATWS for CRBR is sufficiently law. Even given this, the capability of CRBR to accommodate such events and assure acceptably low consequences will also be required.
Statement 7 Most studies of the likely causes of serious accidents conclude through probabilistic risk analysis that over 50% of the risk is associated with human failure to perform as intended. This observation includes human errors in design and construction, in maintenance and testing during operation, and, of course, mistakes by operators in response to unusual occurrences.
Response
The Staff can neither admit nor deny this assertion without more specific information regarding the subject studies.
Statement 8 The NRC has concluded that the reliability of current light water reactor protection systems has not been demonstrated to be adequate and most likely is not adequate.
Response
The Staff neither admits nor denies this assertion, Because of the uncertainty regarding the frequency of ATWS events the NRC has initiated rulemaking proceedings to either reduce.the frequency of ATWS events, reduce the consequences of ATWS events, or both. However, the NRC concluded that there is reasonable assurance of safety of continued operation of LWRs until implementation of a rule is complete.
. II. Contention 3 (renumbered as 2)
Statement 1 Reasonable assurance that a proposed site is a suitable location for a reactor of the general size and type proposed by Applicants requires a determination of an exclusion area and a low population zone as defined in 10 C.F.R. 1 100.3.
Response
The Staff admits these statements except that 10 CFR 100.11(a) provides that an applicant "should determine" an exclusion area and an LPZ, and should calculate a source term; it does not " require" such determinations.
Statement 2 Determination of an exclusion area requires calculations of dosages to the whole body and selected organs from an assumed radioactive release, i.e., a source term.
Response
The Staff admits these statements except that 10 CFR 100,11(c) provides that an applicant "should determine" an exclusion area and an LPZ, and should calculate a source term; it does not " require" such determinations.
Statement 3 The source term assumed in a site suitability assessment must, in terms of its potential health hazard, not be exceeded by the release from any accident considered credible.
Response
The Staff denies this statement.
10 CFR 100.11 Fn. I sets out the specific requirements regarding the site suitability accident evaluation.
1 Statement 4 For purposes of assessing the suitability of the Clinch River site with reasonable assurance, accidents involving the disruption of the reactor core caused in part by failure to scram the reactor must be considered credible.
Response
4 The Staff denies this statement.
Statement 5 For purposes of assessing the suitability of the Clinch River site with reasonable assurance, it is inappropriate to use the source term used for purpo",es of assessing the suitability of a light water reactor site.
Response
The Staff denies these statements. The Staff judged that the i
hypothetical release to the containment of one percent of the plutonium in the core together with the source term of fission products usual for light water reactors provides a better source term for evaluation of the suitability of the site for a reactor of this gene al size and type than the source term usual for light water reactors.
Statement 6 For purposes of assessing the suitability of the Clinch River site with reasonable assurance, it is inappropriate to use the source term used for purposes of assessing tha suitability of a light water reactor site because of significant differences in designs and potential accident scenarios.
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n previous page.
E response to Statement 5 o esponse See hi site River suitability of the Clincht d with absorbed dose source term)
Statement 7 For purposes of assessing thethe health risks associa ees whole body with reasonable assurance, ioactive releasociated with absorbed doses d rad to lung from postulateexceed the health risks ass or thyroids.
a pond to in vague for the Staff to resFirst, admission #7 ref
Response
Admission #7 is too following reasons.
s accidents, whereas meaningful manner, for therning postulated design base the Staff's to site suitability conce dmission #7 refers, concerns not design bases (CDAs),whichare g" is contention #3, to which a of core disrupti,e accidents which " absorbed dose by lun listed in analysis Secondly, it is not clearAbsorbed doses to th accidents.
7 referred to in admission #.rt" (Docket No. 50-537 ted the " Site Suitability Repo calculated or compared ceptors of the FES for different reHealth risks ca organ is specified.
tables releases."
radioactive hole body or a particular unless the dose to the w
9-Statement 8 For purposes of assessing the suitability of the Clinch River site with reasonable assurance, the health risks associated with absorbed dose to bone from postulated radioactive releases (i.e., the source term) exceed the health risks associated with absorbed doses to the whole body or thyroids.
Response
See response to #7.
Statement 9 For purposes of assessing the suitability of the Clinch River site with reasonable assurance, the health risks associated with absorbed dose to lung from postulated radioactive releases (i.e., the source term) are likely to exceed the health risks associated with absorbed doses to the whole body or thyroids.
Response
See response to #7 Statement 10
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For purposes of assessing the suitability of the Clinch River site l
with reasonable assurance, the health risks associated with absorbed dose to bone from postulated radioactive releases (i.e., the source term) are likely to exceed the health risks associated with absorbed doses to the whole body or thyroids.
Response
See response to #7.
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w-g a IV. Contention 8b (renumbered as 11)
Statement 1 Almost without exception, detectable mutations have been found to be mildly or strongly deleterious in their effects.
(See The Effects on Populations of Exposure to Low Levels of Ionizing Radiation (National Academy Press, 1980) (BEIR III) p. 79.)
Response
Staff admits this statement which is a slight rewording of NRDC's request for admission on contention 8a, 21 and 27 which were responded to by staff on November 18, 1976. Staff notes that as reworded non-detectable mutations which would of course be those without detectable deleterious effects are excluded.
Statement 2 In every species studies by geneticists, the overwhelming majority of mutations that have effects large enough to be readily observed are deleterious. (See The Effects on Populations of Exposure to Low Levels of Ionizing Radiation (National Academy Press, Nov. 1972) (BEIR I),
- p. 49.)
Response
The Staff denies this statement, which is essentially the same as NRDC's request for admission on contention 8(a) #24 dated September 16, 1976. While this statement is true for the classes of mutations studies up to the past few years, the recent application of biochemical tech-niques has allowed the study of mutations which may not be all detri-mental.
It may be that the reason that most of the mutations studied in the past had deleterious : *fects is simply that such mutations were easily detected by the tecnniques then available.
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- Statement 3 Because radiation-induced transmitted genetic effects have not been unequivocably demonstrated in man, and because of-the likelihood that adequate information will not soon be forthcoming, estimation of genetic risk must be based on laboratory onimal data.
(See BEIR III, supra, pp. 4-5; 73.)
Response
The Staff admits that there have been no studies demonstrating radiation-induced transmitted genetic effects in man; estimation of i
genetic risk must thus be based primarily upon laboratory animal data.
Nevertheless, the BEIR III Subcommittee on Genetic Effects did utilize some human data in various of it's calculations.
(See BEIR III.)
In addition, Staff believes that the recent analysis of the accumulated data on genetic effects among the offspring of survivors of the atomic bombings at Hiroshima and Nagasaki by Schull, et al. (Schull, Otake and Neel, 1981, Science 213,1220-1227) which suggests that the human j
doubling dose may actually be larger than that for the laboratory mouse, should be taken into consideration in estimating human genetic risk.
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i Statement 4 Any increase in the mutation rate is likely to be harmful to future generations.
(See BEIR III, supra, p. 80.)
Response
i The Staff admits this statement.
i Statement 5 While genetic risk to humans is based largely on animal studies, for purposes of licensing the Clinch River Reactor, one should assume that any increase in the human mutation rate will be harmful to future generations.
Response
The Staff can neither admit nor deny this statement because the phrase "For purposes of licensing the Clinch River Reactor" calls for legal conclusions. However, the Staff does admit that it is prudent to assume that any increase in human mutation rate will be harmful to future generations.
Statement 6 For purposes of licensing the Clinch River Reactor, at low levels of exposure one should assume that the effect of radiation in producing either (1) those genetic disorders which depend on changes in individual genes (gene mutations or small deletions), or (2) those which depend on changes in chromosomes, either in the total number or in the genes' arrangement (chromosomal aberrations) will be proportional to dose.
Response
The Staff can neither admit nor deny this statement by reason of the inclusion of the phrase "For purposes of licensing the Clinch River Reactor" which calls for a legal conclusion. Furthednore, as worded the statement does not make it clear in what way the effects would be " pro-l portional to dose" (i.e. whether the relationship is linear, quadratic, etc.). The Staff admits that it is reasonable and prudent to assume that the frequencies of both sorts of changes will be a linear function of dose for the low doses and low dose rates of concern.
4 Statement 7 It is reasonable to assume that the estimated relative mutation risk for humans exposed to continuous exposure over a large number of genera-tions is 0.02-0.004 per rem (or a doubling dose of 50-250 rems).
(See BEIR III, supra, pp. 96.)
Response
The staff admits this statement. However, using the relative mutation risk (or doubling dose) ranges adopted by BEIR III, it must be kept in mind that recent evidence (Shull, Otake and Neel, 1981, Science 213,1220-1227) strongly suggests these values may be more conservative than thought by the BEIR Subcommittee on Genetic Effects because the human doubling dose may be larger than that for the mouse.
Statement 8 An exposure of one rem received in each generation is estimated to result at genetic equilibrium in an increase of 60-1100 serious genetic disorders per million live-born offspring.
(See BEIR III, supra, pp. 5, 96.)
Response
The Staff admits this statement. However, in the light of the recent analysis by Shull, et al. (1981, Science 213,1220-1227),the range of fron 60-1100 serious genetic disorders may be an overestimate.
In addition, it is appropriate to note that this or any estimate must a considered in relation to the current incidence of such disorders which is taken to be 107,000 per million live-born (BEIR III, Table IV-2, p.85).
Statement 9 It is reasonable to assume that the BEIR III estimate of 60-1100 cases per million live births for 1 rem per person per generation underestimates the total of all genetic and chromosomal diseases or defects and that the number of cases may be in the range of 191'to more than 20,000.
(See John W. Gofman, Radiation and Human Health, Sierra Club Books, 1981, p. 849.)
Response
The Staff denies this statement. The BEIR III estimates which constitute a concensus of views give ranges (1.e. 60-1100 cases)the upper boundary of which were intended to represent the maximum believed credible by the Committee.
Statement 10 It is reasonable to assume that in the first generation one rem of parental exposure before conception throughout the general population will result in an increase of 5-65 additional serious genetic disorders per nillion live-born offspring.
(SeeBEIRIII, supra,page97.)
Response
The Staff admits this statement. However, it should be qualified as for 8 above.
Statement 11 It is reascnable to assume that the BEIR III estimate of 5-65 additoinal cases of serious genetic disorders underestimates the total of all genetic and chromosomal diseases or defects and that the number of cases may be as much as 20 times higher.
(See Gofman, supra, p. 849).
Response
The Staff dentes this statement for the same reasons given for 9 above.
4.
Statement 12 Some experts in radiation health effects research believe that BEIR III underestimates the genetic risks associated with radiation exposure.
(See Gofman, supra, p. 849.)
Response
The Staff denies this statement as it is unaware that Dr. Gofman is an expert in the genetic risks associated with radiation exposure. The Staff admits that this is Dr. Gofman's opinion, but notes that some qualified experts in the genetic risks associated with radiation exposure believe the BEIR III Report overestimates the number of genetic and chromosomal diseases (see Shull, Otrake and Neel, 1981, Science 213, 1220-1227.)
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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of
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UNITED STATES DEPARTMENT OF ENERGY
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Docket No. 50-537 PROJECT MANAGEMENT CORPORATION
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TENNESSEE VALLEY AUTHORITY (Clinch River Breeder Reactor Plant) )
AFFIDAVIT OF JERRY J. SWIFT I, Jerry J. Swift, being duly sworn, state as follows:
1.
I am employed by the U.S. Nuclear Regulatory Commission as a Reactor Engineer, Clinch River Breeder Reactor Program Office, Office of Nuclear Reactor Regulation.
2.
I am duly authorized to participate in answering the March 18, 1982 9th Request for Admissions,Section II, concerning Contention 3 (re-numbered as 2) #1 through #6 and I hereby certify that the answers given are true to the best of my knowledge.
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Jerry J. Swift Subscribed and sworn to before me this day of April, 1982.
Notary Public My Commission expires:
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of
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UNITED STATES DEPARTMENT OF ENERGY Docket No. 50-537 PROJECT MANAGEMENT CORPORATION
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TENNESSEE VALLEY AUTHORITY
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(Clinch River Breeder Reactor Plant)
AFFIDAVIT OF BILL M. MORRIS I, Bill M. Morris, being duly sworn, state as follows:
1.
I am employed by the U.S. Nuclear Regulatory Commission as a Section Leader of the Technical Review Section, Clinch River Breeder Reactor Program Office, Office of Nuclear Reactor Regulation.
2.
I am duly authorized to participate in answering the March 18, 1982 9th Request for Admissions,Section I, concerning Contention 2 (re-numbered as 1) #1 through #8 and I hereby certify that the answers given are true to the best of my knowledge.
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Bill M. Morris Subscribed and sworn to before me this day of April,1982.
Notary Public My Commission expires:
UNITED STATES OF AMERICA NUCLEAR REGULATORY COM?ilSSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of UNITED STATES DEPARTMENT OF ENERGY
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Docket No. 50-537 PROJECT MANAGEMENT CORPORATION
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TENNESSEE VALLEY AUTHORITY (Clinch River Breeder Reactor Plant) )
l AFFIDAVIT OF EDWARD F. BRANAGAN, JR.
1 I, Edward F. Branagan, Jr., being duly sworn, state as follows:
l 1.
I am employed by the U.S. Nuclear Regulatory Comission as a Radiological Physicist, Radiological Assessment Branch, Division of Systems Integration, Office of Nuclear Reactor Regulation.
2.
I am duly authorized to participate in answering the March 18, 1982 9th Request for Admissions,Section II, concerning Contention 3 (re-numbered as 2) #7 through #10 and I hereby certify that the answers given are true to the best of my knowledge.
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EDWARD F. BRANAGAN, JR.
Subscribed and sworn to before me this day of April, 1982.
NOTARY PUBLIC My Commission expires:
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