Northeast Nuclear Energy Company (NNECO), et al., Millstone Nuclear Power Station, Unit No. 3; Environmental Assessment and Finding of No Significant Impact

NUCLEAR REGULATORY COMMISSION

[Docket No. 50-423]

Northeast Nuclear Energy Company (NNECO), et al., Millstone

Nuclear Power Station, Unit No. 3; Environmental Assessment and Finding

of No Significant Impact

The U.S. Nuclear Regulatory Commission (the Commission) is

considering issuance of an amendment to Facility Operating License No.

NPF-49, issued to Northeast Nuclear Energy Company, et al. (the

licensee), for operation of the Millstone Nuclear Power Station, Unit

No. 3 (MP3) located in New London County, Connecticut.

Environmental Assessment

Identification of the Proposed Action

The proposed action is in response to the licensee's application

dated March 19, 1999, requesting an amendment to the operating license

for MP3 to support the rerack of its spent fuel pool to maintain the

capability to fully offload the core from the reactor as the unit

approaches the end of its operating license. To achieve this goal, the

licensee plans to install two types of additional higher density spent

fuel racks into the spent fuel pool. Existing spent fuel racks will

remain in the pool in their current configuration, but are reanalyzed

to only accept fuel lower in reactivity than they are presently

licensed to accept. The proposed additional racks will have a closer

assembly to assembly spacing to increase fuel storage capacity. The

number of fuel assemblies that can be stored in the spent fuel pool

would be increased from 756 assemblies to 1,860 assemblies (an increase

of 1,104).

The Need for the Proposed Action

An increase in spent fuel storage capacity is needed to maintain

the capability for a full core off-load. Loss of full core off-load

capability will occur as a result of refueling outage 6 (RFO 6), that

started on May 1, 1999. The licensee plans to install an additional 15

high density storage racks (with the capacity to store 1,104 fuel

assemblies) following RFO 6 (14 will be installed between RFO 6 and RFO

7, with the last one to be installed later if it is necessary), while

keeping the existing racks in place. The additional capacity will

ensure the capability for a full core off-load as the unit approaches

the end of its operating license (November 25, 2025).

Environmental Impacts of the Proposed Action

Radioactive Waste Treatment

MP3 uses waste treatment systems designed to collect and process

gaseous, liquid, and solid waste that might contain radioactive

material. These radioactive waste treatment systems were evaluated in

the Final Environmental Statement (FES) dated December 1984. The

proposed spent fuel pool expansion will not involve any change in the

radioactive waste treatment systems described in the FES.

[[Page 48676]]

Gaseous Radioactive Wastes

Gaseous releases from the fuel storage area are combined with other

plant exhausts. Normally, the contribution from the fuel storage area

is negligible compared to the other releases and no significant

increases are expected as a result of the expanded storage capacity.

Solid Radioactive Wastes

No significant increase in the volume of solid radioactive waste is

expected from operating with the expanded storage capacity. The

necessity for pool filtration resin replacement is determined primarily

by the requirements for water clarity, and the resin is normally

changed about once a year. During reracking operations, a small amount

of additional resins may be generated by the pool cleanup system on a

one-time basis.

Personnel Doses

During normal operations, personnel working in the fuel storage

area are exposed to radiation from the spent fuel pool. Radiological

conditions are dominated by the most recent batch of discharged spent

fuel. The radioactive inventory of the older fuel is insignificant

compared to that from the recent offload. Analysis shows that the

rerack will not significantly change radiological conditions.

Therefore, the rack expansion project falls within the existing design

basis of MP3's Spent Fuel Pool.

All of the operations involved in reracking will utilize detailed

procedures prepared with full consideration of ALARA [as low as is

reasonably achievable] principles. Similar operations have been

performed in a number of facilities in the past, and there is every

reason to believe that reracking can be safely and efficiently

accomplished at MP3, with low radiation exposure to personnel. Total

dose for the reracking operation is estimated to be between 2 and 5

person-rem. While individual task efforts and doses may differ from

those estimated, the total is believed to be a reasonable estimate for

planning purposes. Divers will be used where necessary, and the

estimated person-rem burden includes an estimate for their possible

dose. The existing radiation protection program at MP3 is adequate for

the reracking operations. Where there is a potential for significant

airborne activity, continuous air monitors will be in operation.

Personnel will wear protective clothing as required and, if necessary,

respiratory protective equipment. Activities will be governed by a

Radiation Work Permit, and personnel monitoring equipment will be

issued to each individual. As a minimum, this will include

thermoluminescent dosimeters (TLDs) and self-reading dosimeters.

Additional personnel monitoring equipment (i.e., extremity TLDs or

multiple TLDs) may be utilized as required. Work, personnel traffic,

and the movement of equipment will be monitored and controlled to

minimize contamination and to assure that dose is maintained ALARA.

On the basis of its review of the licensee's proposal, the NRC

staff concludes that the MP3 spent fuel pool reracking operation can be

performed in a manner that will ensure that doses to workers will be

maintained ALARA. The estimated dose of 2 to 5 person-rem to perform

the proposed spent fuel pool reracking operation is a small fraction of

the annual collective dose accrued at MP3.

Accident Considerations

The licensee has evaluated the consequences of an accidental drop

of a fuel assembly in the spent fuel pool and the consequences of an

accidental drop of a fuel pool gate onto racks. The results show that

such accidents will not distort the racks sufficiently to impair their

functionality. The analysis indicates no radiological consequences from

these postulated accidents. The consequences of a design basis seismic

event have been evaluated and found acceptable. The proposed additional

racks and existing racks have been analyzed in their new configuration

and found safe and impact-free during seismic motion, save for the

baseplate-to-baseplate impacts of the proposed additional racks that

are shown to cause no damage to the racks' cells or Boral (used for

criticality control). The structural capability of the pool walls and

basemat will not be exceeded under the loads. Thus, the consequences of

a seismic event are not significantly increased. The criticality

consequences of a misloading/drop of a fuel assembly during fuel

movement have been evaluated. The minimum subcriticality margin,

keff less than or equal to 0.95, will continue to be

maintained because of the proposed pool water soluble boron related

requirements. The consequences of an accidental drop of a rack module

into the pool during placement have been evaluated. The analysis

confirmed that very limited damage to the liner could occur. Expected

damage from this accident is repairable. Any small seepage occurring is

well within makeup capability, and is mitigated by emergency operating

procedures. The consequences of a spent fuel cask drop into the pool

have not been considered in this submittal since the licensee is not

currently licensed to move a fuel cask into the MP3 cask pit area.

Radiological concerns due to fuel damage are not an issue, since

the fuel handling design basis accident considers the worst case

condition of a falling assembly (a fuel assembly falling onto another

fuel assembly). This design basis accident remains unchanged. Fuel

assembly damage subsequent to a fuel assembly drop is primarily

influenced by the weight and design of the fuel assembly, the drop

height (determines the kinetic energy upon impact), and the orientation

of the falling assembly. Since none of these parameters are changed

under the proposed modification, the results of the previously analyzed

and NRC-accepted design basis accident bound the radiological

consequences of accidents analyzed for the spent fuel pool rerack.

In summary, the proposed action will not increase the probability

or consequences of accidents, no changes are being made to radioactive

waste treatment systems or in the types of any radioactive effluents

that may be released offsite, and the proposed action will not result

in a significant increase in occupational or offsite radiation

exposure. Accordingly, the Commission concludes that there are no

significant radiological environmental impacts associated with the

proposed action.

With regard to potential nonradiological impacts, the proposed

action does not involve any historic sites. The proposed action does

not affect nonradiological plant effluents and has no other

nonradiological environmental impacts. Therefore, there are no

significant nonradiological environmental impacts associated with the

proposed action.

Accordingly, the Commission concludes that there are no significant

environmental impacts associated with this action.

Alternatives to the Proposed Action

Shipping Fuel to a Permanent Federal Fuel Storage/Disposal Facility

Shipment of spent fuel to a high-level radioactive storage facility

is an alternative to increasing the onsite spent fuel storage capacity.

However, the U.S. Department of Energy's (DOE's) high-level radioactive

waste repository is not expected to begin receiving spent fuel until

approximately 2010, at the earliest. In October 1996, the

Administration did commit DOE to begin storing waste at a centralized

location by January 31, 1998. However, no location has been identified

and an interim federal storage

[[Page 48677]]

facility has yet to be identified in advance of a decision on a

permanent repository. Therefore, shipping spent fuel to the DOE

repository is not considered an alternative to increased onsite spent

fuel storage capacity at this time.

Shipping Fuel to a Reprocessing Facility

Reprocessing of spent fuel from the MP3 is not a viable alternative

since there are no operating commercial reprocessing facilities in the

United States. Therefore, spent fuel would have to be shipped to an

overseas facility for reprocessing. However, this approach has never

been used and it would require approval by the Department of State as

well as other entities. Additionally, the cost of spent fuel

reprocessing is not offset by the salvage value of the residual

uranium; reprocessing represents an added cost.

Shipping Fuel to Another Utility, Site, or the Millstone Units 1 or 2

Spent Fuel Pool for Storage

The shipment of fuel to another utility or transferring MP3 spent

fuel to the Millstone Units 1 or 2 spent fuel pool for storage could

provide short-term relief from the storage problem at MP3. The Nuclear

Waste Policy Act of 1982 and 10 CFR part 53, however, clearly place the

responsibility for the interim storage of spent fuel with each owner or

operator of a nuclear plant. The Millstone Units 1 and 2 spent fuel

pools have been designed with the capacity to accommodate each of those

units and, therefore, transferring spent fuel from MP3 to either of

these pools would create fuel storage capacity problems with those

units. The shipment of fuel to another site or transferring it to

Millstone Units 1 or 2 is not an acceptable alternative because of

increased fuel handling risks and additional occupational radiation

exposure, as well as the fact that no additional storage capacity would

be created.

Alternative Creation of Additional Storage Capacity

Alternative technologies that would create additional storage

capacity include rod consolidation, dry cask storage, modular vault dry

storage, and constructing a new pool. Rod consolidation involves

disassembling the spent fuel assemblies and storing the fuel rods from

two or more assemblies in a stainless steel canister that can be stored

in the spent fuel racks. Industry experience with rod consolidation is

currently limited, primarily due to concerns for potential gap activity

release due to rod breakage, the potential for increased fuel cladding

corrosion due to some of the protective oxide layer being scraped off,

and because the prolonged consolidation activity could interfere with

ongoing plant operations. Dry cask storage is a method of transferring

spent fuel, after storage in the pool for several years, to high

capacity casks with passive heat dissipation features. After loading,

the casks are stored outdoors on a seismically qualified concrete pad.

Concerns for dry cask storage include the potential for fuel or cask

handling accidents, potential fuel clad rupture due to high

temperatures, the need for special security provisions, and high costs.

Vault storage consists of storing spent fuel in shielded stainless

steel cylinders in a horizontal configuration in a reinforced concrete

vault. The concrete vault provides missile and earthquake protection

and radiation shielding. Due to large space requirements, a vault

secured area for MP3 would likely have to be located outside the

secured perimeter of the plant site. Concerns for vault dry storage

include security, land consumption, eventual decommissioning of the new

vault, the potential for fuel or clad rupture due to high temperatures,

and high cost. The alternative of constructing and licensing a new fuel

pool is not practical for MP3 because such an effort would require many

years (i.e., 10 years) to complete and would be the most expensive

alternative.

The alternative technologies that could create additional storage

capacity involve additional fuel handling with attendant opportunity

for a fuel handling accident, involve higher cumulative dose to workers

effecting the fuel transfers, require additional security measures, are

significantly more expensive, and would not result in a significant

improvement in environmental impacts compared to the proposed reracking

modifications.

Reduction of Spent Fuel Generation

Generally, improved usage of the fuel and/or operation at a reduced

power level would be an alternative that would decrease the amount of

fuel being stored in the pool and thus increase the amount of time

before full core off-load capacity is lost. With extended burnup of

fuel assemblies, the fuel cycle would be extended and fewer offloads

would be necessary. This is not an alternative for resolving the loss

of full-core offload capability that occurred as a result of MP3

refueling outage that began on May 1, 1999, because the spent fuel

transferred to the pool for storage during this outage eliminated the

licensee's ability to conduct a full core offload. Operating the plant

at a reduced power level would not make effective use of available

resources, and would cause unnecessary economic hardship on the

licensee and its customers. Therefore, reducing the amount of spent

fuel generated by increasing burnup further or reducing power is not

considered a practical alternative.

The No-Action Alternative

As an alternative to the proposed action, the staff considered

denial of the proposed action. Denial of the exemption would result in

no change in current environmental impacts. The environmental impacts

of the proposed exemption and this alternative are similar.

Alternative Use of Resources

This action does not involve the use of any resources not

previously considered in the ``Final Environmental Statement Related to

the Operation of Millstone Nuclear Power Station, Unit No. 3,'' dated

December 1984 (NUREG-1064).

Agencies and Persons Contacted

In accordance with its stated policy, on June 21, 1999, the staff

consulted with the Connecticut State official, Mr. Gary McCahill of the

Department of Environmental Protection, 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 Commission

concludes that the proposed action will not have a significant effect

on the quality of the human environment. Accordingly, the Commission

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 March 19, 1999, which is available for public

inspection at the Commission's Public Document Room, The Gelman

Building, 2120 L Street, NW., Washington, DC, and at the local public

document rooms located at the Learning Resources Center, Three Rivers

Community-Technical College, 574 New London Turnpike, Norwich,

Connecticut, and the Waterford Library, ATTN: Vince Juliano, 49 Rope

Ferry Road, Waterford, Connecticut.

For the Nuclear Regulatory Commission.

[[Page 48678]]

Dated at Rockville, Maryland, this 27th day of August, 1999.

James W. Clifford,

Chief, Section 2, Project Directorate I, Division of Licensing Project

Management, Office of Nuclear Reactor Regulation.

[FR Doc. 99-23158 Filed 9-3-99; 8:45 am]

BILLING CODE 7590-01-P