[Federal Register Volume 67, Number 184 (Monday, September 23, 2002)]
[Notices]
[Pages 59581-59583]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-24152]


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NUCLEAR REGULATORY COMMISSION

[Docket Nos. 50-327 and 50-328]


Tennessee Valley Authority, Sequoyah Nuclear Plant, Units 1 and 
2; Environmental Assessment and Finding of No Significant Impact

    The U.S. Nuclear Regulatory Commission (NRC) is considering 
issuance of amendments to Facility Operating Licenses DPR-77 and DPR-79 
issued to the Tennessee Valley Authority (TVA or the licensee) for 
operation of the Sequoyah Nuclear Plant (SQN), Units 1 and 2, located 
in Hamilton County, Tennessee. Therefore, as required by Title 10, Code 
of Federal Regulations (10 CFR), Section 51.21, the NRC is issuing this 
environmental assessment and finding of no significant impact.

Environmental Assessment

Identification of the Proposed Action

    The proposed action would change SQN's Technical Specifications to 
allow TVA to irradiate up to 2256 tritium-producing burnable absorber 
rods (TPBARs) in each of SQN's two reactor cores. Irradiating the 
TPBARs in the reactor cores supports the U.S. Department of Energy 
(DOE) in maintaining the nation's tritium inventory. TVA will insert 
the TPBARs into positions in the reactor cores where conventional 
burnable poison rods would normally be located (conventional poison 
rods contain boron which reacts with neutrons making them unavailable 
for interacting with uranium atoms, thereby slowing fission and heat 
generation). TPBARs are not reactor fuel and do not generate thermal 
energy for generating electrical energy.
    TPBARs use lithium rather than boron. Neutron irradiation in the 
reactor core converts the lithium in the TPBARs into tritium. After one 
operating cycle, TVA would remove the fuel assemblies containing TPBARs 
from the SQN cores and put them into the spent fuel pool. TVA would 
then, after several weeks (based on plant schedules rather than decay 
considerations), remove the irradiated TPBARs from the fuel assemblies 
and consolidate them into shipping casks for DOE to transport them to 
its tritium extraction facility at its Savannah River Site.
    The proposed action is in accordance with the licensee's 
application dated September 21, 2001, as supplemented by letters of 
June 11, July 19, August 9, August 30, September 5, and September 12, 
2002.

The Need for the Proposed Action

    The proposed action would allow SQN to provide irradiation services 
for DOE to maintain the nation's tritium supply as prescribed by Public 
Law (PL) 106-65. Section 3134 of PL 106-65 directs the Secretary of 
Energy to produce new tritium at TVA's Watts Bar Nuclear Plant (WBN) or 
the SQN plant.

Environmental Impacts of the Proposed Action

    DOE's Environmental Impact Statement, DOE/EIS-0288, Final 
Environmental Impact Statement (EIS) for the Production of Tritium in a 
Commercial Light Water Reactor, dated March 1999, assessed the 
environmental impacts of producing tritium at WBN and SQN. TVA was a 
cooperating Federal agency in preparing this EIS and adopted the EIS in 
accordance with 40 CFR 1506.3(c) of the Council on Environmental 
Quality regulations. DOE also prepared a Tritium Production Core (TPC) 
Topical Report, NDP-98-181, Rev. 1, to address the safety and licensing 
issues associated with incorporating TPBARs in a reference pressurized-
water reactor. The NRC used its Standard Review Plan (NUREG-0800) as 
the basis for evaluating the impact of the TPBARs on a reference plant. 
The NRC reviewed the TPC Topical Report and issued a Safety Evaluation 
Report, NUREG-1672, in May 1999. NUREG-1672 identified 17 plant-
specific interface issues that a licensee would be required to address 
in support of a plant specific amendment to operate a tritium 
production core. TVA's application of September 21, 2001, and 
supplements, addressed these interface issues. The NRC staff is 
reviewing TVA's amendment request and will issue a safety evaluation 
documenting its review.
1. Radiological Impact From Tritium Release to the Reactor Coolant 
System (RCS) Under Normal Plant Operations With 2256 TPBARs in each 
Core
    Tritium levels in the RCSs of large pressurized-water reactors have 
ranged as high as 4000 curies per year (Ci/yr) without exceeding 
regulatory limits. TVA estimated, as discussed in its June 11, 2002, 
letter, that the tritium level in the RCS of each SQN unit would be 
about 3126 Ci/yr with 2256 TPBARs in each unit's reactor. This 
increased tritium level could increase overall occupational exposure, 
but NRC data summarized in NUREG-0713, ``Occupational Radiation 
Exposure at Commercial Nuclear Power Reactors and Other Facilities,'' 
dated 1995, indicate tritium exposure is not an important contributor 
to overall occupational exposure.
    TVA, in its letter dated June 11, 2002, stated that it does not 
expect the increased RCS activity at SQN to greatly affect normal RCS 
feed-and-bleed operation throughout the cycle. The NRC staff finds no 
reason to disagree with TVA's conclusion. Thus, primary coolant 
discharge volumes should be similar to current volumes.
    The staff concludes that the additional dose rate from operating 
SQN with 2256 TPBARs in each reactor will not have a significant impact 
on TVA's ability to control worker radiation doses and keep them well 
within regulatory limits using the controls and practices in SQN's 
existing Radiation Protection Program.
    If increased RCS feed and bleed is required, it may be necessary to 
temporarily store the increased volume of tritiated liquid onsite, or 
to dilute the tritiated liquid to ensure that 10 CFR Part 20 discharge 
limits are met. SQN has sufficient storage tanks to accommodate this 
additional liquid waste.

[[Page 59582]]

2. Radiological Impact From Liquid Effluents Under Normal Plant 
Operations With 2256 TPBARs in Each Core
    The SQN facility has waste-treatment systems designed to collect 
and process liquid waste that may contain radioactive material. The 
tritium in liquid effluents from SQN is diluted to a relatively low 
concentration before it reaches even the most highly exposed members of 
the public. TVA's submittal of June 11, 2002, shows that the total 
additional dose to the maximally-exposed member of the public is 
estimated to be less than 0.01 millirem per year (mrem/yr). This total 
dose, considering the minimal increase from tritium production, is less 
than 1.0 percent of the NRC 3-mrem/yr guideline for effluent exposure 
to the public. The staff concludes that the potential radiological 
impact from liquid effluents on plant workers, members of the public, 
and the environment from operation with the TPC complies with all 
regulatory dose limits.
3. Radiological Impact From Radioactive Gaseous Emissions Under Normal 
Plant Operations With 2256 TPBARs in Each Core
    A portion of the tritium might be released to the atmosphere. The 
amount would depend on plant conditions and the manner in which TVA 
operates SQN. Individuals could be exposed to tritium in a variety of 
pathways if it was released to the atmosphere. These pathways include 
inhalation and skin absorption, as well as consumption of meat, 
vegetables and milk. According to TVA, in its submittal of June 11, 
2002, the calculated incremental increase in the gaseous emission dose 
to the most highly-exposed member of the public through all pathways 
because of the TPBARs would be about 1.7 percent of the NRC annual 15 
mrem exposure guideline for airborne effluents.
4. Radiological Impact From Solid Radioactive Waste Under Normal Plant 
Operations With 2256 TPBARs in Each Core
    Irradiation of TPBARs is expected to increase the number of curies 
and volume of solid radioactive waste, primarily because of disposal 
(offsite) of the associated base plates and thimble plugs, which become 
irradiated. The estimated increase in activity inventory from solid 
waste (assuming 2256 TPBARS) is approximately 2700 Ci/year and the 
estimated increase in volume is from 32,820 cubic feet/year to 32,853 
cubic feet/year. As the result of this increase in solid waste, the 
estimated increase in total worker dose from handling the additional 
solid waste is approximately 1.7 person-rem (about 1.1 percent of the 
dose assessment estimate of record). Offsite shipment and disposal 
would be in accordance with established agreements between TVA and DOE.
5. Radiological Impact to Workers in the Fuel Storage Area Under Normal 
Plant Operations With 2256 TPBARs in Each Core
    The proposed amendments are not expected to significantly affect 
the doses to the workers in the fuel storage area. The TPBARs are 
designed to have minimal effect on plant operations, including 
refueling operations. Unirradiated TPBARs will produce no increase in 
exposure, occupational or public, because they are essentially non-
radioactive. Possible increases in tritium airborne activity may 
increase dose to workers handling and consolidating radioactive TPBARs. 
However, TVA stated, in its submittal of June 11, 2002, that SQN's 
station dose assessment of record bounds the expected increase.
6. Non-Radiological Impact With 2256 TPBARs in Each Core
    The proposal does not affect non-radiological plant effluents. The 
proposal does not result in any significant changes to land use or 
water use. It also does not result in any significant changes to the 
quantity or quality of effluents, and no effects on endangered or 
threatened species or on their habitats are expected. Therefore, no 
changes in, or different types of, non-radiological environmental 
impacts are expected as a result of the amendments.
7. Radiological Impact From Postulated Accidents With 2256 TPBARs in 
the Core
    TVA's submittal of June 11, 2002, discussed the effects of TPBARs 
on the possible consequences of the following postulated accidents 
discussed in SQN's Updated Final Safety Analysis Report (UFSAR):

[sbull] Fuel-handling accident
[sbull] Design basis loss-of-coolant accident (LOCA)
[sbull] Main steamline failure outside of containment
[sbull] Steam generator tube rupture
[sbull] Loss of normal alternating current power to plant auxiliaries
[sbull] Waste gas decay tank failure
[sbull] Rod ejection accident
[sbull] Failure of small lines carrying primary coolant outside 
containment

Discussions of the postulated accidents with the greatest radiological 
consequences appear below.
    a. Fuel-Handling Accident. This accident is defined as dropping a 
spent fuel assembly containing irradiated TPBARs resulting in rupture 
of the cladding on all the fuel rods. TVA's calculations conservatively 
assumed that 24 TPBARs (the maximum possible number) are in the dropped 
spent fuel assembly and that they all rupture and transfer their 
tritium to the spent fuel pool. Releasing this activity to the (1) 
control room boundary, (2) Exclusion Area Boundary over 2 hours, and 
(3) Low Population Zone over 30 days results in the doses to the 
thyroid, skin (beta), whole body (gamma), and Total Effective Dose 
Equivalent (TEDE), as defined in 10 CFR Part 20, that are small 
percentages of regulatory limits.
    b. LOCA. This accident is defined as losing reactor coolant at a 
rate in excess of the capability of the reactor coolant makeup system. 
LOCAs could occur from breaks in pipes in the reactor coolant pressure 
boundary up to and including a break equivalent in size to the double-
ended rupture of the largest pipe in the RCS. TVA conservatively 
assumed that the entire tritium content of the 2256 TPBARs is released 
into containment during a postulated LOCA. Releasing this activity to 
the (1) control room boundary, (2) Exclusion Area Boundary over 2 
hours, and (3) Low Population Zone over 30 days results in doses to the 
thyroid, skin (beta), whole body (gamma), and TEDE that are small 
percentages of regulatory limits.
8. Post-LOCA Hydrogen Generation Inside Containment
    TVA's submittal of September 21, 2001, stated that TPBARs could 
release additional hydrogen to the containment following a large-break 
LOCA (LBLOCA). SQN has emergency operating procedures in place to start 
a hydrogen recombiner train when the containment volumetric percentage 
of hydrogen reaches 3 percent. A previous analysis for a conventional 
(non-TPBAR) core in the SQN UFSAR indicated that for an LBLOCA, with no 
recombiners started, the containment hydrogen concentration reached 
3.75 percent 4 days following event initiation. With additional 
hydrogen from the TPBARs, TVA's analysis indicated that the containment 
hydrogen concentration would only slightly increase 2 days following 
event initiation. If one recombiner train is started 24 hours after 
event initiation for the TPBAR core, the peak containment hydrogen 
concentration is limited to less than 4 percent for up to 6 days. 
Having up to 24 hours to place a recombiner train in service to 
maintain the containment hydrogen

[[Page 59583]]

concentration below 4 percent is adequate in satisfying NRC Regulatory 
Guide 1.7. Accordingly, reactor operation with the TPBARs will not be a 
significant contributor to the post-LOCA hydrogen inventory, and will 
not have a significant impact on the total hydrogen concentration 
within the containment when compared to the values associated with the 
non-TPBAR core. The maximum containment hydrogen concentration can be 
maintained at less than the lower flammability limit of 4.0-volume-
percent, with one recombiner train started at a 3-percent hydrogen 
concentration approximately 24 hours after an LBLOCA.

Summary

    The Commission has completed its evaluation of the proposed action. 
The proposed action will not significantly increase the probability or 
consequences of accidents, no changes are being made in the types of 
effluents that may be released offsite, and there is no significant 
increase in occupational or public radiation exposure. Therefore, there 
are no significant radiological environmental impacts associated with 
the proposed action.
    With regard to potential non-radiological impacts, the proposed 
action does not have a potential to affect historic sites. It does not 
affect non-radiological plant effluents and has no other environmental 
impact. Therefore, there are no significant non-radiological 
environmental impacts associated with the proposed action.

Environmental Impacts of the Alternatives to the Proposed Action

    As an alternative to the proposed action, the staff considered 
denial of the proposed action (i.e., the ``no-action'' alternative). 
Denial of the application would result in no significant change in 
current environmental impacts. However, because there are no 
significant environmental impacts associated with this action, and 
because PL 106-65 directs that DOE produce tritium at WBN or SQN, this 
is not considered a viable option.

Alternative Use of Resources

    DOE evaluated alternatives to the proposed action, including 
completing construction of one or both of the Bellefonte Nuclear Plant 
Units and construction of an accelerator facility at the Savannah River 
site and concluded that the proposed action has the least environmental 
impact of the options considered. The NRC has no reason to disagree 
with DOE's decision.

Agencies and Persons Consulted

    On September 16, 2002, the staff consulted with the Tennessee State 
official, Elizabeth Flannagan of the Tennessee Bureau of Radiological 
Health, regarding the environmental impact of the proposed action. The 
State official had no comments.

Finding of No Significant Impact

    On the basis of the environmental assessment, the NRC concludes 
that the proposed action will not have a significant effect on the 
quality of the human environment. Accordingly, the NRC has determined 
not to prepare an environmental impact statement for the proposed 
action.
    For further details with respect to the proposed action, see the 
licensee's letter dated September 21, 2001, as supplemented by letters 
dated June 11, July 19, August 9, August 30, September 5, and September 
12, 2002. Documents may be examined, and/or copied for a fee, at the 
NRC's Public Document Room (PDR), located at One White Flint North, 
11555 Rockville Pike (first floor), Rockville, Maryland. Publicly 
available records will be accessible electronically from the Agencywide 
Documents Access and Management System (ADAMS) Public Electronic 
Reading Room on the Internet at the NRC Web site, http://www.nrc.gov/reading-rm/adams.html. Persons who do not have access to ADAMS or who 
encounter problems in accessing the documents located in ADAMS, should 
contact the NRC PDR Reference staff by telephone at 1-800-397-4209 or 
301-415-4737, or by e-mail to [email protected].

    Dated at Rockville, Maryland, this 17th day of September 2002.

    For the Nuclear Regulatory Commission.
Ronald W. Hernan,
Senior Project Manager, Section 2, Project Directorate II, Division of 
Licensing Project Management, Office of Nuclear Reactor Regulation.
[FR Doc. 02-24152 Filed 9-20-02; 8:45 am]
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