[Federal Register Volume 64, Number 173 (Wednesday, September 8, 1999)]
[Notices]
[Pages 48856-48857]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-23297]
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NUCLEAR REGULATORY COMMISSION
[Docket Nos. 50-295 and 50-304]
Commonwealth Edison Company; (Zion Nuclear Power Station, Units 1
and 2); Exemption
I.
Commonwealth Edison Company (ComEd or the licensee) is the holder
of Facility Operating License Nos. DPR-39 and DPR-48, which authorize
the licensee to possess the Zion Nuclear Power Station (ZNPS). The
license states, among other things, that the facility is subject to all
the rules, regulations, and orders of the US Nuclear Regulatory
Commission (the Commission or NRC) now or hereafter in effect. The
facility consists of two pressurized-water reactors located at the
ComEd site on the west shore of Lake Michigan about 40 miles north of
Chicago, Illinois, in the extreme eastern portion of the city of Zion,
Illinois (Lake County). 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 50.12(a) of 10 CFR, ``Specific exemption,'' states that.* *
*
The Commission may, upon application by any interested person, or upon
its own initiative, grant exemptions from the requirements of the
regulations of this part, which are: (1) Authorized by law, will not
present an undue risk to the public health and safety, and are
consistent with the common defense and security. (2) The Commission
will not consider granting an exemption unless special circumstances
are present.
Section 50.12(a)(2)(ii) of 10 CFR states that special circumstances
are present when ``Application of the regulation in the particular
circumstances would not serve the underlying purpose of the rule or is
not necessary to achieve the underlying purpose of the rule.* * *'' The
underlying purpose of sections 50.47(b) and 50.47(c)(2) is to ensure
that there is reasonable assurance that adequate protective measures
can and will be taken in the event of a radiological emergency, to
establish plume exposure and ingestion pathway emergency planning zones
for nuclear power plants, and to ensure that licensees maintain
effective offsite and onsite emergency plans.
By letter dated April 13, 1999, ComEd requested an exemption from
certain provisions of 10 CFR 50.47(b) and 10 CFR 50.47(c)(2) on the
basis that the permanently shutdown and defueled condition of the ZNPS
had substantially reduced the risk to public health and safety. In
addition, the licensee submitted a proposed Defueled Station Emergency
Plan (DSEP) for NRC's approval. The DSEP proposed to discontinue
offsite emergency planning activities and to reduce the scope of onsite
emergency planning. Thus, exemptions from certain provisions of 10 CFR
50.47(b) and 50.47(c)(2) are required to implement the proposed DSEP to
maintain compliance with the regulation.
By letter dated April 13, 1999, and supplemental letters dated July
8, July 19, and August 30, 1999, the licensee also submitted an
analysis of the radiological consequences of a postulated event, an
analysis to determine the maximum Zircaloy cladding temperature in the
spent fuel pool (SFP) with the fuel exposed to an air environment, and
an analysis to determine the potential upper limit radiation fields at
the exclusion area boundary.
III.
The licensee stated that special circumstances exist at ZNPS
because of the station's permanently shutdown and defueled condition.
The standards in 10 CFR 50.47(b) and the requirements in 10 CFR
50.47(c)(2) were developed taking into consideration the risks
associated with operation of a nuclear power reactor at its licensed
full-power level. The risks include the potential for an accident with
offsite radiological dose consequences. There are no design basis
accidents or other credible events for ZNPS that would result in a
radiological dose beyond the exclusion area boundary that would exceed
the Environmental Protection Agency's (EPA) Protective Action
Guidelines (PAGs). Therefore, the application of all of the standards
in 10 CFR 50.47(b) and the requirements of 10 CFR 50.47(c)(2) are not
necessary to achieve the underlying purpose of those rules.
The licensee analyzed the heatup characteristics of the spent fuel
from a beyond design basis event that results in the complete loss of
spent fuel pool (SFP) water, when cooling depends on the natural
circulation of air through the spent fuel racks. The licensee presented
[[Page 48857]]
the results of an analysis showing that as of June 30, 1999, decay heat
could not heat the spent fuel cladding above 482 deg.C in the event
all water was drained from the SFP. The staff reviewed the licensee's
analysis and found the licensee's value for peak fuel cladding
temperature acceptable. On the basis of a staff determination that fuel
cladding will remain intact at this temperature, the staff concluded
that a complete loss of water from the ZNPS SFP would not result in a
release off site 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 (a beyond-design-basis event).
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 off site 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
gamma radiation dose rate at the exclusion area boundary would be
0.00294 rad per hour at an outside air temperature of 21 deg.C. At
this rate, it would take 14 days for the event to exceed the EPA early-
phase PAG of 1 rem. The EPA early-phase PAG is defined as the period
beginning at the projected or actual initiation of a release and
extending a few days later. 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
14 days available for action allow sufficient time to develop and
implement mitigative actions and provide confidence that additional
offsite measures could be taken without planning if efforts to
reestablish shielding over the fuel are delayed.
The standards and requirements that remain in effect are listed in
Attachment 1 to the licensee's letter of April 13, 1999, and Attachment
2 to the licensee's letter of July 8, 1999. On the basis of this
review, the staff finds that the radiological consequences of accidents
possible at ZNPS are substantially lower than those at an operating
plant. The upper bound of offsite dose consequences limits the highest
attainable emergency class to the alert level. In addition, because of
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. Accordingly, the
Commission has determined that special circumstances as defined in 10
CFR 50.12(a)(2)(ii) exist.
IV.
The Commission has determined that, pursuant to 10 CFR 50.12, the
exemption is authorized by law, will not present an undue risk to the
public health and safety and is consistent with the common defense and
security, and is otherwise in the public interest. Therefore, the
Commission hereby grants Commonwealth Edison Company an exemption from
certain requirements of 10 CFR 50.47(b) and 10 CFR 50.47(c)(2).
Pursuant to 10 CFR 51.32, the Commission has determined that
granting of this exemption will have no significant impact on the
environment (64 FR 45981).
This exemption is effective upon issuance.
Dated at Rockville, Maryland, this 31st day of August 1999.
For the Nuclear Regulatory Commission.
John A. Zwolinski,
Director, Division of Licensing Project Management, Office of Nuclear
Reactor Regulation.
[FR Doc. 99-23297 Filed 9-7-99; 8:45 am]
BILLING CODE 7590-01-P
