ML20207L513
| ML20207L513 | |
| Person / Time | |
|---|---|
| Issue date: | 10/20/1986 |
| From: | Stello V NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | |
| References | |
| FRN-48FR50083, RULE-PRM-50-37 PR-861020, NUDOCS 8701120199 | |
| Download: ML20207L513 (11) | |
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~86 DEC 11 A10:03 10 CFR PART 50 7
Docket No. FRH-50-37 Lillian McNally; Denial cf Petition of Rulemaking AGENCY: Nuclear Regulatory Comission.
ACTION: Denial of Petition for Rulemakirg
SUMMARY
- The Nuclear Regulatory Comission is denying a petition submitted by Lillian McNally. The petitioner requested the Comission to amend its regulations: (1) to limit the concentrations of deuterium (heavy hydrogen of mass 2); (2) further limit tritium (radicactive heavy hydrogen of mass 3) concentrations in waters circulated "in and around" nuclear power plants; and (3) not permit the recombination of hydrcgen and oxygen. The petitioner states that these restrictions would increase public health protection. The Comission is denying the petition because tritium releases from nuclear power plants to the environment already are considered te be "as low as is reasonably achievable" under existing NRC regulaticns and the cessation of the use of hydrogen-oxygen recombiners would decrease plant safety and could increase health risks.
ADDRESSES: Copies of the petition, public coments received on the petition and tabular data sumaries on tritium releases and doses from reactors are available for inspection and copying under Docket No. PRM-50-37 in the NRC i
Public Document Room, 1717 H Street NW., Washington, DC.
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FOR FURTHER INFORMATION CONTACT:
Harold T. Peterson, Jr., Safety Research Application Branch, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC 20555, telephone (301) 443-7691.
SUPPLEMENTARY INFORMATION: A petition for rulemaking was filed by Lillian McNally on July 6,1983, and, as amended, her petition was docketed on September 23, 1983 as PRM-50-37 and noticed in the Federal Register on October 31, 1983 [45 FR 50083].
The amended petition requested the Commission to set standards for tritium and deuterium such that:
Water circulated in and around Nuclear Power Plants is not to exceed the natural environnent concentration of deuterium and tritium for one year; that in one year the concentration shall be limited to less than one part by weight in 10,000 parts, and that the amount by which the contaminants
[ exceed this limit] shall be reviewed annually thereafter to determine the attainable purity of circulating water.
The petitioner also requested that:
In no case should the reintroduction of contaminated water produced by the recombination of molecular hydrogen and oxygen in the plant be permitted.
SUMMARY
OF PUBLIC COMMENTS l
l Four public comments were received by the NRC in response to the notice of receipt for this petition. Three respondents reconcended denial of the petition. One respondent favored granting the petition.
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COMMENT FAVORING THE PETITION The commenter favoring granting the petition cites the following points:
1.
Comment: NRC and its licensees are mandated by NEPA to avoid
" degradation, risk to health and safety or other undesirable and 1
unintended consequences."
NRC Response: The section of the National Environmental Policy Act (Public Law 91-190) referred to by this comme.ter [9 101(b)(3),
42U.S.C.94331(b)(3)] states:
...(3) attain the widest range of beneficial uses of the en-vironment without degradation, risk to health or safety, or other undesirable and unintended consequences,...
However, the preface which precedes this paragraph i 101(b), 42 U.S.C.4331]statesinpart:
...(b) In order to carry out the policy set forth in this Act, it is the continuing responsibility of the Federal government to use all practicable means, consistent with other essential-considerations of national policy, to improve and coordinate Federal plans, functions, programs and resources to the end that the Nation may...
This preface indicates that the paragraphs which follow it, including paragraph (3), represent a series of national goals. The i
NRC believes that its existing regulations regarding radiation i
protection meet these goals.
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2.
Connent: Water is ubiquitous so that tritiated water is a concern regarding potential health effects.
NRC Response: Tritiated water can be of public health significance and, for that reason, its release to the environment is controlled 4
by the NRC under its regulations in 10 CFR Part 20.
3.
Comnent: NPDES [the EPA National Pollutant Discharge Elimination System) fails to deal with tritium.
NRC Response: Materials regulated under the authority of the Atomic Energy Act are not subject to the Federal Water Pollution Control Act Amendments of 1972 [Public Law 92-500, 86 Stat. 816, 33 U.S.C.1151],Section402ofwhichcreatedtheNationalPollutant Discharge Elimination System (NPDES). This explains why NPDES does not deal with tritium. Tritium releases to the environment, either to the atmosphere or in liquid effluents, are regulated under the Atomic Energy Act of 1954, as amended.
PUBLIC COP 94ENTS OPPOSED TO THE PETITION The connenters who recommended denial of the petition cite the following specific reasons:
1.
Connent: The petitioner fails to demonstrate that releases of radioactive water to the atmosphere are at levels which have produced any public health concerns. Such releases have been within l
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NRC limits and the NRC limits in 10 CFR Part 20 and 10 CFR Part 20, Appendix B, are adequate to protect public health.
NRC Response: This issue is addressed in the NRC staff analysis supporting the recomendations to deny this petition.
2.
Coment:
It would be impossible to control the tritium and deuterium in reactor waters to levels not exceeding naturally-occurring levels as tritium and deuterium are both produced during reactor operation.
NRC Response: The petitioner intends that a deuterium / tritium removal process be employed to remove the deuterium prior to irradiation and tritium and deuterium as they are formed. The existence of a pending patent by Ms. McNally on a deuterium-tritium removal process is not a relevant factor in the Comission's decision on her petition.
3.
Coment: Petitioner's desired limit for a concentration of 1 in 10,000 "doesn't make sense" for tritium as it corresponds to about 1,000 C1/ liter which is many orders of magnitude above normal tritium levels during operation.
NRC Response: This is addressed in the NRC staff analysis which follows.
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4.
Comment: The petitioner does not present any data on the process to remove tritium. There is no proof of cost efficiency and therefore this process cannot be used to establish standards.
NRC Response: The NRC does not require specific details of the petitioner's proposed tritium separation process.
It is sufficient to note that there are existing methods for the separation of tritium and hydrogen isotopes which could be applied. The NRC regulations contain criteria for what constitutes "as low as rea-sonably achievable" which can be applied to the collective (population) doses from tritium releases in order to define justi-fiable control costs. No known method of isotopic separation could be used at a cost of less than $100 per ruclear power plant (See Analysisbelow).
5.
Coninent: Deuterium is outside of NRC's jurisdiction to regulate.
NRC Response: Deuterium (hydrogen-2) is neither a source, byproduct nor a special nuclear material regulated by the NRC under the Atomic Energy Act of 1954, as amended. However, to the extent that deuterium could affect public health and safety (such as through tritium production), it could be regulated by the NRC under its authority to regulate production and utilization facilities, including nuclear power reactors.
Other public connents are considered in connection with the analysis of the merits of the petition itself.
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ANALYSIS OF THE PETITION In light-water reactors (LWRs), deuterium in cooling water is a minor source of tritium production in the coolant; leakage of fission-product tritium produced in the fuel and by neutron reactions with boron and lithium are the principal sources of tritium (Ref. I through 6). In pressurized-water reactors, tritium is formed directly in the coolant by interactions with baron and lithium in addition to the deuterium (1, 2, 3 4,and6). Tritium is produced in the fuel rods and in boron control rods or plates of both BWRs and some PWRs, but it is generally contained in these materials and large quantities do not reach the coolant (4, 5 through6). However, release of even one percent of the tritium con-tained in the fuel or boron control rods would exceed the deuterium reac-tion as a source of tritium in a BWR. Because of the presence of these other sources of tritium in a LWR, removal or reduction of the deuterium concentration in the coolant as proposed by the petitioner would not result in any major reduction in the overall tritium production nor would it result in decreased tritium releases to the environment.
Petitioner's suggested limit for deuterium of one part by weight in 10,000 is 3 to 4 times lower than the natural concentration of deuterium in water.
Furthermore, additional tritium and deuterium will be produced by neutron capture by hydrogen during operation of the reactor.
This condition would require reducing the deuterium and tritium concen-trations at the plant water intakes to less than ambient levels in order to attempt to offset the levels produced from reactor operation.
The Commission has criteria determining the practicability of additional reductions in radioactive effluents from nuclear power 7
reactors. These criteria define "as lcw as is reasonably achiev able" or "ALARA" levels of radioactive materials in light-water-cooled nuclear power reactor effluents and are in Appendix I to 10 CFR Part 50. One of the criteria for ALARA is that additional equipment for effluent reduction and control must be added if the reduction in the collective (population) dose (person-rem) afforded by the control equipment multiplied by the worth of exposure reduction ($1,000 per person-rem reduced) would exceed the cost of adding this technology.
The estimated population doses associated with tritium releases from light-water reactor (LWR) effluents in 1981 ranged between 1.1 x 10-6 person-rem to 3.4 person-rem at individual LWR sites (6). The total for all reactor sites was 8.3 person-rem. This means that, using the Appendix I criterion of $1,000 per person-rem reduced, expenditures for tritium control up to $3,400 per year maximum per reactor might be justified. The maximum total cost for all plants that could be justified would be $8,300 (8.3 person-rem x $1,000 per person-rem). The average justifiable cost per plant would be around $100. The processing of in-plant liquid and effluent streams containing tritium may entail handling tens of thousands of gallons of liquids. There is no demonstrated separation technology that could concentrate and separate tritium and deuterium from this volume of liquid for a hundred dollars or i
less. Therefore, the NRC concludes that the petitioner's request to require a reduction in tritium levels in waters circulating in and around reactor plants is not " reasonably achievable" under the Comission's established criteria in Appendix I to 10 CFR Part 50.
The application of the one part in ten thousand (by weight; 1:10,000) ratio to tritium would, as one of the public comenters noted, 8
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result in reactor coolant tritium concentrations which greatly exceed those that could be tolerated without excessive dose to plant workers. A tritium-to-hydrogen ratio of 1:10,000 by weight corresponds to a tritium activity concentration of approximately one curie per gram (or per milliliter) which is equivalent to 1,000 curies per liter of water.
Although it would be almost impossible to reach such concentrations in a light-water reactor, such a limit could not be tolerated for tritium because of worker protection considerations. Therefore, the portion of the petition requesting the NRC to adopt this limit for tritium is unacceptable.
The petitioner also requested that:
In no case should the reintroduction of contaminated water produced by the recombination of molecular hydrogen and oxygen in the plant be permitted.
Hydrogen and oxygen gases are produced in normal reactor operation by the radulytic (radiation-induced) decomposition of water. The purpose of the petitioner's request would be to keep tritium-contaminated hydrogen gas from mixing with the large volume of water within the plant.
These gases are potentially explosive and can represent a significant portion of the total quantity of radioactive waste gases produced. Controlled recombination of these gases back into water reduces not only the poten-tial explosive hazard, but also the volume of the gaseous wastes which have to be stored and treated. The volume reduction resulting from recombination of hydrogen and oxygen permits longer in-plant holdup of radioactive waste gases, longer periods of radioactive decay and, consequently, results in lower radiation doses from gaseous effluents.
Because the elimination of recombiners could have an adverse impact on 9
i the potential safety of reactor systems, would have adverse impacts on waste gas holdup times and would increase offsite radiation doses, and cannot be justified solely on the potential reduction of the already-low doses from tritium, the NRC also denies this aspect of the petition.
BASIS FOR DENIAL The NRC denies the petitioner's request to establish limits on the deuterium and tritium concentrations in reactor coolants on the basis that:
(1) reductions in the deuterium levels would not necessarily produce corresponding reductions in tritium production, (2) tritium in the coolant of operating light-water reactors already is at or beneath j
the numerical limits requested by the petitioner and (3) the associated tritium releases from nuclear power plants are already "as low as is reasonably achievable." The request not to permit hydrogen and oxygen recombination is also denied because this recombination is desirable both for safety reasons and for reducing the levels of gaseous radioactive releases. Therefore, the petition is denied.
References Cited 1.
C. L. Weaver, E. D. Harward, and H. T. Peterson, Jr., " Tritium in the Environment from Nuclear Power Plants," Public Health Reports, 84_(4):363-371 (April 1969).
2.
H. T. Peterson, Jr., J. E. Martin, C. L. Weaver and E. D. Harward,
" Environmental Tritium Contamination from Increasing. Utilization of Nuclear Energy Sources" in Environmental Contamination by Radioactive Materials (Proc. FAO-IAEA - WHO Sentinar.
- Vienna, Austria 24-28 March 1969) Vienna:
IAEA pp 35-58(1969).
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3.
J. Locante and D. D. Malinowski, " Tritium in Pressurized Water Reactors" in Tritium (A. A. Moghissi and M. W. Carter, eds.)
CONF-710809, Las Vegas, NY: Graphics (May 1973) pp. 45-57.
4.
J. M. Iacovino, Jr., " Tritium Control Strategies in PWRs," paper presented at the American Nuclear Society winter meeting, Washington, D.C., November 18, 1976. Abstract in Trans. Amer.
Nucl. Soc., 24:106-108 (Nov. 1976).
5.
J. M. Smith and R. S. Gilbert, " Tritium Experience in Boiling Water Reactors" in Tritium (A. A. Moghissi and M. W. Carter, eds)
Messenger Graphics, Las Vegas, NV (May 1973) pp 57-68.
6.
H. T. Peterson, Jr. and D. A. Baker, " Tritium Production, Releases and Population Doses at Nuclear Power Reactors," Fusion Technology, 8(2):2544-2550(September 1985).
Dated at Bethesda, MD this Jb day of
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For the Nuclear Regulatory Comission m
A
/u v4 Victor Stello', Jr.V Executive Director for Operations 1
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