[Federal Register Volume 65, Number 207 (Wednesday, October 25, 2000)]
[Notices]
[Pages 63900-63902]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-27384]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-275]
Pacific Gas and Electric Co.; Diablo Canyon Power Plant, Unit 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-80, issued to Pacific Gas and Electric Company (PG&E, or the
licensee), for operation of the Diablo Canyon Nuclear Power Plant, Unit
1 (DCNPP), located in San Luis Obispo County, California.
Environmental Assessment
Identification of Proposed Action
The proposed action would allow PG&E to increase the maximum
reactor core power level from 3338 megawatts thermal (MWt) to 3411 MWt,
which is an increase of 2.2 percent of rated core thermal power for
DCNPP Unit 1.
[[Page 63901]]
The proposed action is in accordance with PG&E's application for
amendment dated December 31, 1999, as supplemented by letters dated
January 18, July 7, September 22, and September 29, 2000.
The Need for the Proposed Action
The proposed action would permit an increase in the licensed core
thermal power from 3338 MWt to 3411 MWt and would provide the
flexibility to increase the potential electrical output of DCNPP Unit
1.
Environmental Impacts of the Proposed Action
PG&E has submitted an environmental evaluation supporting the
proposed power uprate and provided a summary of its conclusions
concerning both the radiological and non-radiological environmental
impacts of the proposed action. Based on the NRC's independent analyses
and the evaluation performed by the licensee, the staff concludes that
the proposed increase in power is not expected to result in a
significant environmental impact.
Radiological Environmental Assessment
Radwaste Systems
The reactor coolant contains activated corrosion products, which
are the result of metallic materials entering the water and being
activated in the reactor region. Under power uprate conditions, the
feedwater flow increases with power and the activation rate in the
reactor region increases with power. The net result may be an increase
in the activated corrosion product production. However, the total
volume of processed waste is not expected to increase appreciably.
Non-condensible radioactive gas from the main condenser, along with
air in-leakage, normally contains activation gases (principally N-16,
O-19 and N-13) and fission product radioactive noble gases. This is the
major source of radioactive gas (greater than all other sources
combined). These non-condensible gases, along with non-radioactive air,
are continuously removed from the main condensers which discharge into
the offgas system. The gaseous effluents will remain within the
original limits following implementation of the power uprate.
PG&E has concluded that the operation of the radwaste systems at
DCNPP will not be impacted by operation at uprated power conditions and
the slight increase in effluents discharged would continue to meet the
requirements of Part 20 of Title 10 of the Code of Federal Regulations
(10 CFR) and 10 CFR part 50, appendix I. Therefore, the power uprate
will not appreciably affect the licensee's ability to process liquid or
gaseous radioactive effluents and there are no significant
environmental effects from radiological releases.
Dose Consideration
PG&E evaluated the effects of power uprate on the radiation sources
within the plant and radiation levels during normal and post-accident
conditions. Post-operation radiation levels in most areas of the plant
are expected to increase by no more than the percentage increase in
power level. In a few areas near the spent fuel pool cooling system
piping and the reactor water piping, where accumulation of corrosion
product crud is expected, as well as near some liquid radwaste
equipment, the increase could be slightly higher. In this regard,
procedural controls are expected to compensate for increased radiation
levels. Occupational doses for normal operations will be maintained
within acceptable limits by the site's as-low-as-reasonably-achievable
program, which is required by 10 CFR 20.1101(b).
The power uprate would not involve significant increases in offsite
doses to the public from noble gases, airborne particulates, iodine,
tritium, or liquid effluents. A review of the normal radiological
effluent doses shows that, at the current power level, doses are less
than one percent of the doses allowed by the plant's technical
specifications (TS). Present offsite radiation levels are a negligible
portion of background radiation. Therefore, the normal offsite doses
would not be significantly affected by operation at the uprated power
level and would remain below the limits of 10 CFR part 20 and 10 CFR
part 50, appendix I.
The change in core inventory that would result from the power
uprate is expected to increase post-accident radiation levels by no
more than the percentage increase in power level. The licensee
reanalyzed the large break loss-of-coolant accident (LOCA), the small
break LOCA, the overtemperature and overpressure T
(OTT/OPT) setpoint calculation, and the accidental
reactor coolant system (RCS) depressurization event. The residual heat
removal (RHR) cooldown calculation and main steam line break at full
power were also reanalyzed as part of the uprate project. The slight
increase expected in the post-accident radiation levels would have no
significant effect on the plant nor on the habitability of the control
room envelope, the Emergency Operations Facility, or the Technical
Support Center. Thus, the licensee has determined that access to areas
requiring post-accident occupancy would not be significantly affected
by the power uprate. The licensee evaluated the whole body and thyroid
doses at the exclusion area boundary that might result from the
postulated design basis LOCA and determined that expected doses remain
below established regulatory limits. Therefore, the results of the
radiological analyses remain below the 10 CFR Part 100 guidelines and
all radiological safety margins would be maintained if the amendment
were granted.
Summary
The proposed power uprate would not significantly increase the
probability or consequences of accidents, would not involve any new
radiological release pathways or would not result in a significant
increase in occupational or public radiation exposure, and would not
result in significant additional fuel cycle environmental impacts.
Accordingly, the NRC staff concludes that there are no significant
radiological environmental impacts associated with the proposed action.
Non-Radiological Environmental Assessment
The licensee reviewed the non-radiological environmental impacts of
the requested power uprate based on information submitted in the
Environmental Report, Operating License Stage, the NRC Final
Environmental Statement (FES), and the requirements of the
Environmental Protection Plan. Based on this review, the licensee
concluded that the proposed power uprate would have no significant
effect on the non-radiological elements of concern and the plant will
be operated in an environmentally acceptable manner as established by
the FES. In addition, the licensee states that existing Federal, State,
and local regulatory permits presently in effect accommodate the power
uprate without modification.
The cooling water systems at DCNPP (e.g., circulating water and
auxiliary saltwater systems) are drawn from the ultimate heatsink,
Diablo Cove, part of the Pacific Ocean. DCNPP has determined that the
power uprate would not cause any change to the DCNPP Environmental
Protection Plan, however, it would reduce the margin between DCNPP
performance and the allowable heat rejection to the Pacific Ocean. The
licensee is allowed a maximum of 22 deg.F between the cooling water
intake and outflow between the two units. The outflows of both units
[[Page 63902]]
mix together, therefore a 2.2 percent uprate of DCNPP Unit 1 will tend
to increase the temperature change by 1.1 percent, or approximately 0.2
deg.F.
DCNPP operates in compliance with a National Pollution Discharge
Elimination System (NPDES) Permit, which requires all effluents to be
closely monitored to assure compliance with the permit levels. DCNPP
does not expect any effluent increases due to the power uprate of DCNPP
Unit 1. With regards to potential non-radiological impacts, the
proposed action would not change the method of operation at DCNPP or
the methods of handling effluents. No changes to land use would result
and the proposed action does not involve any historic sites. Therefore,
no new or different types of non-radiological environmental impacts are
expected. Accordingly, the NRC concludes that there are no significant
non-radiological environmental impacts associated with the proposed
action.
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 change in current
environmental impacts, but would reduce the operational flexibility
that would be afforded by the proposed change. The environmental
impacts of the proposed action and the alternative action are not
significantly different.
Alternative Use of Resources
This action does not involve the use of any resources not
previously considered in the FES for DCNPP.
Agencies and Persons Consulted
In accordance with its stated policy, on October 3, 2000, the staff
consulted with the California State official, Mr. Steve Hsu, of the
Radiologic Health Branch of the State Department of Health Services,
regarding the environmental impact of the proposed action. The State
official had no comments.
Finding of no Significant Impact
Based upon 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 December 31, 1999, as supplemented by letters
dated January 18, July 7, September 22, and September 29, 2000, which
may be examined, and/or copied for a fee, at the NRC's Public Document
Room, located at One White Flint North, 11555 Rockville Pike (first
floor), Rockville, Maryland. Publicly available records will be
accessible electronically from the ADAMS Public Library component on
the NRC Web site (the Electronic Reading Room).
Dated at Rockville, Maryland this 19th day of October 2000.
For the Nuclear Regulatory Commission.
Stephen Dembek,
Chief, Section 2, Project Directorate IV & Decommissioning, Division of
Licensing Project Management, Office of Nuclear Reactor Regulation.
[FR Doc. 00-27384 Filed 10-24-00; 8:45 am]
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