[Federal Register Volume 63, Number 172 (Friday, September 4, 1998)]
[Notices]
[Pages 47331-47333]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-23878]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-213]


Connecticut Yankee Atomic Power Company and Haddam Neck Plant; 
Exemption

I

    Connecticut Yankee Atomic Power Company (CYAPCO or the licensee) is 
the holder of Facility Operating License No. DPR-61, which authorizes 
the licensee to possess the Haddam Neck Plant (HNP). The license 
states, among other things, that the facility is subject to all the 
rules, regulations, and orders of the U.S. Nuclear Regulatory 
Commission (the Commission or NRC) now or hereafter in effect. The 
facility consists of a pressurized-water reactor located at the 
licensee's site in Middlesex County, Connecticut. The facility is 
permanently shut down and defueled and the licensee is no longer 
authorized to operate or place fuel in the reactor.

II

    Section 50.54(q) requires power reactor licensees to follow and 
maintain in effect emergency plans that meet the standards of Section 
50.47(b) and the requirements of Appendix E to 10 CFR Part 50.
    Pursuant to 10 CFR 50.12(a), NRC may grant exemptions from the 
requirements of the regulations, which are (1) authorized by law, will 
not present an undue risk to public health and safety, and are 
consistent with the common defense and security, and (2) present 
special circumstances. Special circumstances exist when application of 
the regulation in the particular circumstance would not serve the 
underlying purpose of the rule or is not necessary to achieve the 
underlying purpose of the rule (10 CFR 50.12(a)(2)(ii)). The underlying 
purpose of Section 50.54(q) is to ensure that licensees follow and 
maintain in effect emergency plans which provide reasonable assurance 
that adequate protective measures can and will be taken in the event of 
an emergency at a nuclear reactor.

III

    By letter dated May 30, 1997, CYAPCO requested an exemption from 
the provision of 10 CFR 50.54(q) that requires emergency plans to meet 
all of the standards of 10 CFR 50.47(b) and all of the requirements of 
Appendix E of Part 50. The request for exemption was based on the 
substantially reduced the risk to public health and safety resulting 
from the permanently shutdown and defueled condition of the Haddam Neck 
Plant (HNP). In addition, the licensee submitted a proposed Defueled 
Emergency Plan (DEP) for NRC approval. The DEP proposed to discontinue 
offsite emergency planning activities and to reduce the scope of onsite 
emergency planning, which met only a portion of the standards and 
requirements. Thus, an exemption is required from the provision of 10 
CFR 50.54(q) that requires emergency plans to meet all of the standards 
of 10 CFR 50.47(b) and all of the requirements of Appendix E of Part 
50. By letter dated September 19, 1997, the licensee submitted the 
Emergency Action Levels that it proposed to use with the DEP. By letter 
dated September 26, 1997, the licensee submitted the results of an 
assessment of the ability of the HNP spent fuel to heat up in the 
absence of water in the spent fuel pool (SFP). By letter dated October 
21, 1997, the licensee submitted additional information on certain 
aspects of the DEP and identified the specific standards and 
requirements of 10 CFR 50.47(b) and Appendix E of Part 50 which the 
proposed DEP would no longer meet. By letters dated December 18, 1997, 
January 22, March 25, June 19, and July 31, 1998, the licensee sent 
additional information on the proposed DEP. Tables 1 and 2 of 
Attachment 2 of the licensee's March 25, 1998 letter revised and 
consolidated the list of standards and requirements of 10 CFR 50.47(b) 
and Appendix E to Part 50 that would remain in effect.
    The licensee stated that special circumstances exist at HNP because 
of the plant's permanently shutdown and defueled condition. With the 
plant in this condition, most of the design-basis accidents postulated 
for operating reactors are no longer possible.
    However, CYAPCO postulated two design-basis accidents that are 
relevant to the permanently shutdown condition: (1) a release from 
combustible radioactive ion exchange resin, and (2) fuel handling 
accidents. With the exception of Kr-85, the noble gas and iodine 
nuclides that contribute to the dose consequences of releases from 
operating reactors have decayed to a negligible amount. CYAPCO 
calculated doses due to resin handling and fuel handling accidents and 
concluded that doses at the residence nearest to HNP would not exceed 
the Environmental Protection Agency (EPA) Protective Action Guides 
(PAGs) for activation of the offsite emergency response organization.
    In addition, the licensee has evaluated the potential consequences 
of a beyond-

[[Page 47332]]

design-basis event that would completely remove the spent fuel pool 
water inventory. The analysis demonstrated that, even with no cooling 
by water, the decay heat load has decreased to the point that air 
cooling would maintain fuel cladding temperatures low enough to ensure 
the integrity of the cladding material.
    In the permanently shutdown and defueled condition, the source term 
of nuclides that are readily dispersible in air and the energy 
available to propel radioactive materials off site are significantly 
reduced in comparison to an operating plant. The staff has evaluated 
the potential for a permanently shutdown plant with spent fuel stored 
in the spent fuel pool to generate a release of radioactive material 
that would result in offsite dose consequences. The two source terms of 
primary concern are low-level radioactive waste generated by 
decommissioning activities and the spent fuel.
    The first source term, from low-level radioactive waste at the 
site, is much lower than the one from the spent fuel. However, the 
potential dose consequences of a release from a low-level waste 
container have been evaluated. An event that would provide a motive 
force for the release and transport of airborne activity offsite is a 
fire in low-level radioactive waste. The bounding accident for low-
level radioactive wastes present on site is a fire in ion exchange 
resins used to process wastes from a reactor coolant system chemical 
decontamination. While they are in use, the resins are immersed in 
water. Upon depletion, used ion exchange resins are placed in 
containers called liners for dewatering prior to shipment to a disposal 
site. The licensee calculated that a fire in a resin liner, loaded with 
wastes having the maximum activity allowed by procedure, would result 
in an offsite dose which does not exceed the EPA PAGs. The staff 
reviewed the calculational methods and assumptions used by the licensee 
to determine the consequences of a resin fire and found them to be 
acceptable. The staff concludes that the consequences of a resin liner 
fire at HNP would not exceed the EPA PAGs.
    The second source term considered is spent fuel. However, wet 
storage of spent fuel possesses inherently large safety margins due to 
the simplicity and robustness of the SFP design. The design basis 
includes the ability to withstand an earthquake and retain the ability 
to hold sufficient water to adequately cool and shield the spent fuel. 
Thus, the loss of all the water from the Haddam Neck SFP is a beyond-
design-basis event, with a very low probability of occurring.
    However, there are two potential consequences from a beyond-design-
basis event that postulates the complete removal of water from the SFP. 
In the absence of water cooling, during the period that decay heat 
generation is relatively high the fuel could heat up to such a degree 
that a release could occur. In the absence of water shielding, the 
radiation from the fuel could cause radiation exposure to individuals 
offsite from the scatter of gamma rays streaming up from the pool.
    In order for a release that would result in offsite dose 
consequences to occur, a motive force must exist to cause radioactive 
material to move into an unrestricted area. At a permanently shutdown 
and defueled plant, decay heat in the spent fuel could provide this 
force. However, decay heat decreases over time, and at some point it 
can no longer overcome the ability of the fuel cladding to retain 
fission products. When decay heat can no longer cause the fuel to heat 
to the point where fission products could be released, a significant 
release off the site is no longer possible by this means.
    The licensee analyzed the heatup characteristics of the spent fuel 
in the absence of SFP water, when cooling depends on the natural 
circulation of air through the spent fuel racks. By letter dated 
September 26, 1997, the licensee presented the results of an analysis 
showing that as of October 1, 1997, decay heat could not heat the spent 
fuel cladding above 538 deg. C, in the event all water was drained from 
the SFP. The licensee's heat up analysis was based on a particular 
configuration of the spent fuel in the SFP. By letter dated December 
18, 1997, the licensee stated, that as of October 23, 1997, the spent 
fuel had been moved into a configuration consistent with the analysis. 
The staff evaluated the licensee's analysis by performing heat up 
calculations using computer codes validated to be accurate to within 
15 deg.C of actual peak fuel cladding temperatures. The licensee's 
value for peak fuel cladding temperature was found to be acceptable. On 
the basis of a previous staff determination that fuel cladding will 
remain intact if its temperature remains below 565 deg.C, the staff 
concluded that it is no longer possible for a complete loss of water 
from the Haddam Neck SFP to result in a release offsite that exceeds 
the early phase EPA PAGs.
    Although a significant release of radioactive material from the 
spent fuel is no longer possible, in the absence of water cooling, a 
potential exists for radiation exposure to an offsite individual in the 
event that shielding of the fuel is lost. Water and the concrete pool 
structure serve as radiation shielding on the sides of the pool. 
However, water alone provides most of the shielding above the spent 
fuel. A loss of shielding above the fuel could increase the radiation 
levels offsite because of the gamma rays streaming up out of the pool 
being scattered back to a receptor at the site boundary. The licensee 
calculated the offsite radiological impact of a postulated complete 
loss of SFP water and determined that the dose rate at the residence 
nearest to HNP would be 0.016 rem per hour. At that rate, it would take 
2.6 days for the event to exceed the EPA early phase PAG of 1 rem. The 
PAGs were developed to respond to a mobile airborne plume that could 
transport and deposit radioactive material over a large area. In 
contrast, the radiation field formed by scatter from a drained SFP 
would be stationary, rather than moving, and would not cause transport 
or deposition of radioactive materials. The 2.6 days available for 
action allows sufficient time to develop and implement mitigative 
actions and provides confidence that additional offsite measures could 
be taken without planning, if efforts to reestablish shielding over the 
fuel are delayed.
    The staff has evaluated the radiological consequences, onsite 
emergency organization, facilities, equipment, procedures, and support 
resources of the licensee's proposed DEP. The staff reviewed the 
licensee's proposed DEP against the planning standards in 10 CFR 
50.47(b) and (d), the requirements of Appendix E to 10 CFR Part 50, the 
acceptance criteria in NUREG-0654/FEMA-REP-1, Revision 1, and the 
guidance contained in NUMARC/NESP-007, Revision 2. The staff review 
took into consideration the permanently shutdown and defueled status of 
the facility, the configuration of the stored fuel, and the length of 
time since power operation.

IV

    The NRC staff has completed its review of the licensee's request 
for an exemption from the requirement of 10 CFR 50.54(q) that emergency 
plans must meet all of the standards of 50.47(b) and all of the 
requirements of Appendix E of 10 CFR Part 50. Standards and 
requirements that remain in effect are listed in Tables 1 and 2 of 
Attachment 2 to the licensee's letter dated March 25, 1998 (Docket No. 
50-213, Accession No. 9804020370). On the basis of this

[[Page 47333]]

review, the NRC staff finds that the radiological consequences of 
accidents possible at HNP are substantially lower than those at an 
operating plant. The analyses submitted by the licensee are consistent 
with the commitment made in their Post Shutdown Decommissioning 
Activities Report, which stated that any radiation exposure to an 
offsite individual will be bounded by the EPA PAGs. The upper bound of 
offsite dose consequences limits the highest attainable emergency class 
to the alert level. In addition, due to the reduced consequences of 
radiological events still possible at the site, the scope of the onsite 
emergency preparedness organization may be reduced. Thus, the 
underlying purpose of the regulations will not be adversely affected by 
eliminating offsite emergency planning activities or reducing the scope 
of onsite emergency planning.
    For these reasons, the Commission has determined that, pursuant to 
10 CFR 50.12, elimination of the offsite emergency planning activities 
and implementation of the DEP will not present an undue risk to public 
health and safety and is consistent with the common defense and 
security. Further, special circumstances are present as stated in 10 
CFR 50.12(a)(2)(ii).
    Pursuant to 10 CFR 51.32, the Commission has determined that 
granting this exemption will have no significant impact on the 
environment (63 FR 43967, dated August 17, 1998).
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland this 28th day of August 1998.

    For the Nuclear Regulatory Commission.
Samuel J. Collins,
Director, Office of Nuclear Reactor Regulation.
[FR Doc. 98-23878 Filed 9-3-98; 8:45 am]
BILLING CODE 7590-01-P