[Federal Register Volume 63, Number 29 (Thursday, February 12, 1998)]
[Notices]
[Pages 7186-7188]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-3582]


=======================================================================
-----------------------------------------------------------------------

NUCLEAR REGULATORY COMMISSION

[Docket No. 50-285]


In the Matter of Omaha Public Power District; Fort Calhoun 
Station, Unit No. 1; Exemption

I

    The Omaha Public Power District (OPPD) is the holder of Facility 
Operating License No. DPR-40 for the Fort Calhoun Station, Unit No. 1 
(FCS) which authorizes operation of the Fort Calhoun Station, Unit No. 
1. The license provides, among other things, that the licensee is 
subject to all rules, regulations, and orders of the Commission now or 
hereafter in effect.
    The facility consists of one pressurized-water reactor at the 
licensee's site located in Washington County, Nebraska.

II

    Section 70.24 of Title 10 of the Code of Federal Regulations, 
``Criticality Accident Requirements,'' requires that each licensee 
authorized to possess special nuclear material (SNM) shall maintain a 
criticality accident monitoring system in each area where such material 
is handled, used, or stored. Subsections (a)(1) and (a)(2) of 10 CFR 
70.24 specify detection and sensitivity requirements that these 
monitors must meet. Subsection (a)(1) also specifies that all areas 
subject to criticality accident monitoring must be covered by two 
detectors. Subsection (a)(3) of 10 CFR 70.24 requires licensees to 
maintain emergency procedures for each area in which this licensed SNM 
is handled, used, or stored and provides that (1) the procedures ensure 
that all personnel withdraw to an area of safety upon the sounding of a 
criticality accident monitor alarm, (2) the procedures must include 
drills to familiarize personnel with the evacuation plan, and (3) the 
procedures designate responsible individuals for determining the cause 
of the alarm and placement of radiation survey instruments in 
accessible locations for use in such an emergency. Subsection (b)(1) of 
10 CFR 70.24 requires licensees to have a means to identify quickly 
personnel who have received a dose of 10 rads or more. Subsection 
(b)(2) of 10

[[Page 7187]]

CFR 70.24 requires licensees to maintain personnel decontamination 
facilities, to maintain arrangements for a physician and other medical 
personnel qualified to handle radiation emergencies, and to maintain 
arrangements for the transportation of contaminated individuals to 
treatment facilities outside the site boundary. Paragraph (c) of 10 CFR 
70.24 exempts Part 50 licensees from the requirements of paragraph (b) 
of 10 CFR 70.24 for SNM used or to be used in the reactor. Paragraph 
(d) of 10 CFR 70.24 states that any licensee who believes that there is 
good cause why he should be granted an exemption from all or part of 10 
CFR 70.24 may apply to the Commission for such an exemption and shall 
specify the reasons for the relief requested.

III

    The SNM that could be assembled into a critical mass at FCS is in 
the form of nuclear fuel. In addition, the quantity of SNM other than 
fuel that is stored on site in any given location is small enough to 
preclude achieving a critical mass. As set forth below, the 
Commission's technical staff has evaluated the possibility of an 
inadvertent criticality of the nuclear fuel at FCS.
    By letter dated August 29, 1997, as supplemented by letter dated 
October 23, 1997, the licensee requested an exemption from the 
requirements of 10 CFR 70.24 in its entirety for FCS. The licensee 
proposes to handle and store unirradiated fuel without having a 
criticality monitoring system with the sensitivity required by 10 CFR 
70.24.
    The basis for the staff to determine that inadvertent or accidental 
criticality is extremely unlikely can be established through compliance 
with the FCS Technical Specifications, the geometric spacing of fuel 
assemblies in the new fuel storage racks and spent fuel storage pool, 
and administrative controls imposed on fuel handling procedures.
    SNM, as nuclear fuel, is stored in the new fuel storage rack and in 
the spent fuel pool. The spent fuel pool is used to store irradiated 
fuel under water after its discharge from the reactor and new 
(unirradiated) fuel prior to loading into the reactor. New fuel is 
stored in the new fuel storage rack in a dry condition.
    SNM is also present in the form of excore fission chamber detectors 
and startup neutron sources. The small quantity of SNM present in these 
latter items precludes an inadvertent criticality.
    The spent fuel pool is designed to store the fuel in a geometric 
array using a solid neutron absorber that precludes criticality. The 
effective neutron multiplication factor, keff, is maintained 
less than or equal to 0.95 by the solid neutron absorber for fuel 
enriched to 4.5 wt% U-235. Although soluble boron is maintained in the 
spent fuel pool, no credit is taken for it in determining 
keff.
    The new fuel storage racks may be used to receive and store new 
fuel in a dry condition upon arrival onsite and prior to loading in the 
reactor or spent fuel pool. The spacing between new fuel assemblies and 
the solid neutron absorbers in the storage racks is sufficient to 
maintain the dry array in a subcritical condition. The new fuel storage 
rack is located at an elevation of 18.75 feet above the main floor 
which provides adequate drainage and precludes flooding. Because no 
fire protection sprinkler system exists in this area, there is no 
source of low-density aqueous foam optimum moderation. The current 
approved maximum enrichment of 4.5 wt% U-235 for the new fuel 
assemblies results in a maximum keff of less than 0.90 under 
dry conditions.
    Nuclear fuel is moved between the NRC-approved shipping containers, 
the new fuel storage racks, the reactor vessel, and the spent fuel pool 
to accommodate refueling operations. In all cases, fuel movements are 
procedurally controlled and designed to preclude conditions involving 
criticality concerns. For example, during new fuel receipt inspection, 
FCS fuel handling procedures allow a maximum of two fuel assemblies to 
be in the inspection stands in the receipt area (out of the shipping 
container and not in the new fuel storage rack). However, when 
installed in the inspection stands, both assemblies have an edge-to-
edge separation distance in excess of 14 feet. This geometric spacing 
is well in excess of that maintained by the NRC-approved shipping 
container (approximately 3 inches). There are no sprinklers in the new 
fuel receipt/storage room and the use of fire fighting equipment is 
very unlikely since there are no combustible materials permanently 
stored in this room. Even if fire suppression water were introduced 
into the room, sufficient drainage exists to preclude potential 
moderation of new fuel assemblies. Therefore, because of the large 
physical separation of new fuel assemblies and the extremely unlikely 
event of any potential moderation, there is sufficient assurance that 
keff remains less than 0.95, thus precluding criticality.
    FCS was licensed to the 70 General Design Criteria for Nuclear 
Power Plant Construction published as drafts in the Federal Register 
(32 FR 10213) on July 11, 1967. Draft Criterion 18, Monitoring Fuel and 
Waste Storage, was met. As noted in Section 11.2.3 and Appendix G of 
the FCS Updated Safety Analysis Report, area monitoring of dose rates 
is supplied in the containment and auxiliary buildings, including the 
fuel storage areas. Local and control room alarms and indicators (not 
necessarily meeting the 10 CFR 70.24 sensitivity requirements) are 
provided to alert personnel to take appropriate action in the unlikely 
event of excessive radiation levels due to accidental criticality.
    The purpose of the criticality monitors required by 10 CFR 70.24 is 
to ensure that if a criticality were to occur during the handling of 
SNM, personnel would be alerted to that fact and would take appropriate 
action. In view of the above information, the staff has determined that 
it is extremely unlikely for an inadvertent criticality to occur in SNM 
handling or storage areas at FCS. Criticality is precluded with the 
present design configuration, Technical Specification requirements, 
administrative controls, and the fuel handling equipment and 
procedures. In addition, as described above, the licensee has radiation 
monitors, as required by General Design Criterion 63, in fuel storage 
and handling areas. These monitors will alert personnel to excessive 
radiation levels and allow them to initiate appropriate safety actions. 
The low probability of an inadvertent criticality, together with the 
licensee's adherence to General Design Criterion 63, constitutes good 
cause for granting an exemption to the requirements of 10 CFR 70.24.

IV

    Accordingly, the Commission has determined that, pursuant to 10 CFR 
70.14, this exemption is authorized by law, will not endanger life or 
property or the common defense and security, and is otherwise in the 
public interest. Therefore, the Commission hereby grants Omaha Public 
Power District an exemption as described in Section II above from 10 
CFR 70.24, ``Criticality Accident Requirements'' for the Fort Calhoun 
Station.
    Pursuant to 10 CFR 51.32, the Commission has determined that the 
granting of this exemption will have no significant impact on the 
quality of the human environment (63 FR 5821).
    This exemption is effective upon issuance.

For the Nuclear Regulatory Commission.


[[Page 7188]]


    Dated at Rockville, Maryland, this 6th day of February 1998.
Frank J. Miraglia, Jr.,
Acting Director, Office of Nuclear Reactor Regulation.
[FR Doc. 98-3582 Filed 2-11-98; 8:45 am]
BILLING CODE 7590-01-P