Niagara Mohawk Power Corporation; Nine Mile Point Nuclear Station, Unit No. 1 Environmental Assessment and Finding of No Significant Impact

NUCLEAR REGULATORY COMMISSION

[Docket No. 50-220]

Niagara Mohawk Power Corporation; Nine Mile Point Nuclear

Station, Unit No. 1 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.

DPR-63, issued to Niagara Mohawk Power Corporation (the licensee), for

operation of the Nine Mile Point Nuclear Station, Unit No. 1 (NMP1),

located in the town of Scriba, Oswego County, New York.

Environmental Assessment

Identification of the Proposed Action

The proposed action would increase the number of fuel assemblies

that can be stored in the NMP1 spent fuel pool (SFP) from 2776 (i.e.,

1066 in the northern half of the pool and 1710 in the southern half of

the pool) to 4086. The modification will be achieved by two separate

campaigns. For the 1999 refueling outage (RFO15), the licensee will

first replace the non-poison racks in the northern half of the pool

with high density racks providing 1840 storage cells. Later, as further

capacity increase is warranted, the licensee will replace the racks in

the southern half of the pool with high density racks providing 2246

storage cells. The design of the new high density spent fuel storage

racks incorporates Boral as a neutron absorber in the cell walls to

allow for more dense storage of spent fuel.

The proposed action is in accordance with the licensee's

application for amendment dated May 15, 1998, as

[[Page 18060]]

supplemented September 25, October 13, December 9 (two letters), 1998;

January 11 and April 1, 1999.

The Need for the Proposed Action

An increase in spent fuel storage capacity is needed to reestablish

full core off-load capability. Loss of that capability will occur as a

result of RFO-15, currently scheduled to start April 11, 1999. Thus,

after RFO-15, the licensee will replace the eight non-poison rack

modules in the northern half of the NMP1 pool (which currently provides

1066 spent fuel storage locations) with new poison rack modules

providing 1840 storage locations. Ultimately, additional capacity will

be needed to accommodate future refueling outages. Thus, as further

capacity increase is warranted by the increasing fuel inventory in the

pool, the licensee will increase the capacity of the southern half of

the pool (currently limited to 1,710 storage locations) so as to

provide a total pool capacity for 4086 spent fuel assemblies. This

capacity of 4086 storage locations is sufficient to extend full core

off-load capability to at least the expiration date of the plant

operating license, August 22, 2009.

Environmental Impacts of the Proposed Action

Radioactive Waste Treatment

NMP1 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 January 1974. The

proposed SFP expansion will not involve any change in the waste

treatment systems described in the FES.

Gaseous Radioactive Wastes

The storage of additional spent fuel assemblies in the pool is not

expected to affect the releases of radioactive gases from the pool.

Gaseous fission products such as Krypton-85 and Iodine-131 are produced

by the fuel in the core during reactor operation. A small percentage of

these fission gases is released to the reactor coolant from the small

number of fuel assemblies that are expected to develop leaks during

reactor operation. During refueling operations, some of these fission

products enter the pool and are subsequently released into the air.

Since the frequency of refueling (and therefore the number of freshly

offloaded spent fuel assemblies stored in the pool at any one time)

will not increase, there will be no increase in the amounts of these

types of fission products released into the atmosphere as a result of

the increased pool fuel storage capacity.

The increased heat load on the pool from the storage of additional

spent fuel assemblies will potentially result in an increase in the

pool's evaporation rate. However, this increased evaporation rate is

not expected to result in an increase in the amount of gaseous tritium

released from the pool. The overall release of radioactive gases from

NMP1 will remain a small fraction of the limits of 10 CFR 20.1301.

Solid Radioactive Wastes

Spent resins are generated by the processing of SFP water through

the pool's purification system at NMP1. These spent resins are disposed

of as solid radioactive waste (``radwaste''). The water turbulence

caused by the removal and replacement operations in the pool

(``reracking'') may result in some resuspension of particulate matter

in the pool. This could result in a temporary increase in the

replacement frequency of the resin in the SFP purification system

during the pool reracking operation. The licensee will use an

underwater vacuum to clean the floor of the pool following removal of

the old spent fuel rack modules. Vacuuming the SFP floor will remove

any extraneous debris and crud and ensure visual clarity in the pool

(to facilitate diving operations). Filters from this underwater

vacuuming will be a source of solid radwaste. These filters and resins

are collected and disposed of in accordance with existing plant

radwaste procedures. Additional solid radwaste will consist of the old

spent fuel rack modules themselves, as well as any interferences or

pool hardware that may have to be removed from the pool to permit

installation of the new rack modules. The old rack modules and removed

hardware will be decontaminated, placed in shipping containers approved

by the U.S. Department of Transportation, and shipped offsite to a

licensed processing or disposal facility. Other than the radwaste

generated during the actual reracking operation, the NRC staff does not

expect that the additional fuel storage provided by the increased SFP

storage capacity will result in a significant change in the generation

of solid radwaste at NMP1.

Liquid Radioactive Wastes

The release of radioactive liquids will not be affected directly as

a result of the SFP modifications. The SFP ion exchanger resins remove

soluble radioactive materials from the pool water. When the resins are

replaced, the small amount of resin sluice water that is released is

processed by the radwaste system. As previously stated, the frequency

of resin replacement may increase slightly during the installation of

the new racks. However, the amount of radioactive liquid released to

the environment as a result of the proposed SFP expansion is expected

to be negligible.

Occupational Dose Consideration

Radiation Protection personnel at NMP1 will constantly monitor the

doses to the workers during the SFP expansion operation. If it becomes

necessary to utilize divers for the reracking operation, the licensee

will equip each diver with whole-body and extremity dosimeters having

remote, above surface, readouts that will be continuously monitored by

Health Physics personnel. The total occupational dose to plant workers

as a result of the SFP expansion operation is estimated to be between 6

and 12 person-rem. This dose estimate is comparable to doses for

similar SFP modifications performed at other nuclear plants. The

upcoming SFP rack installation will follow detailed procedures prepared

with full consideration of ALARA (as low as is reasonably achievable)

principles.

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

staff concludes that the NMP1 SFP reracking operation can be performed

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

ALARA. The estimated dose of 6 to 12 person-rem to perform the proposed

SFP reracking operation is a small fraction of the annual collective

dose accrued at NMP1.

Accident Considerations

In its application, the licensee evaluated the possible

consequences of a fuel handling accident to determine the thyroid and

whole-body doses at the site's Exclusion Area Boundary, Low Population

Zone, and in the NMP1 Control Room. The proposed SFP rack installation

at NMP1 will not affect any of the assumptions or inputs used in

evaluating the dose consequences of a fuel handling accident and,

therefore, will not result in an increase in the doses from a

postulated fuel handling accident.

The NRC staff reviewed the licensee's analysis of a fuel handling

accident and performed confirmatory calculations to check the

acceptability of the licensee's doses. The NRC staff's calculations

confirmed that the thyroid doses at the Exclusion Area Boundary, Low

[[Page 18061]]

Population Zone, and in the Control Room from a fuel handling accident

meet the acceptance criteria and that the licensee's calculations are

acceptable. The results of the NRC staff's calculations are presented

in the Safety Evaluation to be issued with the license amendment.

An accidental cask drop into the pool continues to be unlikely as

none of the features preventing such a drop (e.g., design and

maintenance of the main hoist, the controlled cask movement path, and

the hydraulic guide cylinder cask drop protection system) are affected

by the proposed action. The licensee also found that the consequences

of a loss of SFP cooling was acceptable in that ample time would be

available for the operators to re-establish cooling before the onset of

pool boiling. Evaluation of a design basis seismic event indicated the

new racks would remain safe and impact-free, the structural capability

of the pool would not be exceeded, and the reactor building and crane

structure would continue to retain necessary safety margins. Thus,

these potential accidents have no environmental consequences.

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 affect nonradiological plant effluents and has no other

nonradiological environmental impact.

Accordingly, the Commission concludes that there are no significant

environmental impacts associated with the proposed 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 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 Nine Mile Point Nuclear Station

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 or Site or to the NMP2 Spent Fuel Pool

for Storage

The shipment of fuel to another utility or transferring NMP1 spent

fuel to the NMP2 spent fuel pool for storage would provide short-term

relief from the storage problem at NMP1. 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 NMP2 spent fuel pool has been designed with capacity

to accommodate NMP2 and, therefore, transferring spent fuel from NMP1

to the NMP2 pool would create fuel storage capacity problems for NMP2.

The shipment of fuel to another site or transferring it to NMP2 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.

Alternatives Creating 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 into 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 cost. 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 NMP1 would have

to be located outside the secured perimeter of the plant site. Concerns

for vault dry storage include security, land consumption, eventual

decommission 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 NMP1

because such an effort would require about 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 an 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 will occur as a result of the NMP1

refueling outage scheduled to begin about April 11, 1999, because the

spent fuel to be transferred to the pool for storage has now almost

completed its operating history in the core. For many years now, NMP1

has been

[[Page 18062]]

operating on the basis of 24-month refueling cycles, with core designs

and fuel management schemes optimized accordingly. 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

The NRC staff also 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. The

environmental impacts of the proposed action and the alternative

actions are similar.

Alternative Use of Resources

This action does not involve the use of any resources not

previously considered in the Final Environmental Statement for the Nine

Mile Point Nuclear Station, Unit No. 1.

Agencies and Persons Consulted

In accordance with its stated policy, on April 7, 1999, the NRC

staff consulted with the New York State official, Jack Spath of the New

York State Research and Development Authority, 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 May 15, 1998, as supplemented by letters dated

September 25, October 13, December 9 (two letters), 1998; January 11

and April 1, 1999. These letters are available for public inspection at

the Commission's Public Document Room, The Gelman Building, 2120 L

Street, NW., Washington, D.C., and at the local public document room

located at the Reference and Documents Department, Penfield Library,

State University of New York, Oswego, New York 13126.

Dated at Rockville, Maryland, this 7th day of April 1999.

For the Nuclear Regulatory Commission.

S. Singh Bajwa,

Chief, Section 1, Project Directorate I, Division of Licensing Project

Management, Office of Nuclear Reactor Regulation.

[FR Doc. 99-9172 Filed 4-12-99; 8:45 am]

BILLING CODE 7590-01-P