[Federal Register Volume 62, Number 126 (Tuesday, July 1, 1997)]
[Notices]
[Pages 35533-35535]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-17145]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-482]


Wolf Creek Nuclear Operating Corporation (Wolf Creek Generating 
Station, Unit 1); Exemption

I

    On June 4, 1985, the Commission issued Facility Operating License 
No. NPF-42 to Wolf Creek Nuclear Operating Corporation (the licensee) 
for the Wolf Creek Generating Station, Unit 1 (WCGS). 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.

II

    Subsection (a) of 10 CFR 70.24, ``Criticality Accident 
Requirements,'' requires that each licensee authorized to possess 
special nuclear material (SNM) shall maintain in each area where such 
material is handled, used, or stored, an appropriate criticality 
monitoring system. In accordance with Subsection (a)(1) of 10 CFR 
70.24, coverage of all such areas at WCGS shall be provided by two 
criticality detectors. However, exemptions may be requested pursuant to 
10 CFR 70.24(d), provided that the licensee believes that good cause 
exists for the exemption. In particular, Regulatory Guide 8.12, 
Revision 2, ``Criticality Accident Alarm System,'' states that it is 
appropriate to request an exemption from 10 CFR 70.24 if an evaluation 
determines that a potential for criticality does not exist, as for 
example where geometric spacing is used to preclude criticality.
    By letter dated September 19, 1995, and supplement dated March 21, 
1997, the licensee requested an exemption from the requirements of 10 
CFR 70.24. A previous exemption from the provisions of 10 CFR Part 
70.24 for the storage of SNM, including reactor fuel assemblies 
[maximum amount of 2,400 kg of U-235 in uranium enriched to no more 
than 3.50 weight percent (w/o)], was granted to Wolf Creek Nuclear

[[Page 35534]]

Operating Corporation (WCNOC) in NRC Materials License No. SNM-1929. 
The materials license was issued on May 9, 1984, and expired upon 
conversion of the construction permit to an operating license on June 
4, 1985. In this request the licensee proposes to handle and store 
unirradiated fuel in the fuel handling building and in the new fuel 
section of the spent fuel pool without having a criticality monitoring 
system with two separate criticality detectors or performing the 
emergency drills as required by 10 CFR 70.24.
    The basis for the exemption is that the potential for accidental 
criticality is precluded because of the geometric spacing of fuel in 
the new fuel storage facility and spent fuel pool and administrative 
controls imposed on fuel handling procedures from the time the fuel is 
removed from approved shipping containers, until it is placed in 
specially designed storage racks.
    SNM is present at WCGS principally in the form of nuclear fuel, 
although other quantities of SNM are present in the incore nuclear 
instrumentation, health physics sources, and in quality control 
radiography sources. However, the small quantity of SNM present in 
these latter items precludes any criticality concerns.
    A new fuel storage facility (NFSF) is located within the fuel 
building, and provides onsite dry storage for 66 new fuel assemblies 
(approximately one-third core), arranged in three double rows (2x11) of 
ports. Each port will hold just one fuel assembly. The ports within 
each double row are on 21-inch centers and there is a nominal 28-inch 
aisle between each pair of rows. The spacing between new fuel 
assemblies in the storage racks is sufficient to maintain the array in 
a subcritical condition even under accident conditions where unborated 
water is assumed present. For the flooded condition, assuming new fuel 
with a maximum enrichment of 4.5 w/o U-235 in place, the effective 
multiplication factor (keff) does not exceed 0.95. The 
effective multiplication factor does not exceed 0.98 assuming optimum 
moderation by low-density sources of moderator such as aqueous foam or 
mist. The NFSF is protected from the effects of natural phenomena, 
including earthquakes, tornadoes, hurricanes, floods, and external 
missiles. The NFSF is designed to perform its intended function and 
maintain structural integrity after a safe shutdown earthquake (SSE) or 
following a postulated hazard, such as fire, internal missiles, or pipe 
break. The new fuel storage racks are designed for the following loads 
and combinations thereof: dead loads, live loads (fuel assemblies), 
crane uplift load (up to 5000 pounds), SSE loads and operating basis 
earthquake (OBE) loads. The new fuel storage racks are designed to 
seismic Category I criteria, and are anchored to the seismic Category I 
floor and walls of the NSFS.
    The new fuel is stored in an enclosed vault with reinforced 
concrete walls and a steel plate top. Hinged covers are provided 
directly over each fuel storage position. The covers and fuel racks are 
sized to prevent insertion of a fuel assembly into other than its 
prescribed location. The steel protective cover protects the storage 
racks from possible dropped objects and has been determined capable of 
sustaining the maximum fuel assembly drop. The new fuel storage racks, 
loaded with fuel, are designed to resist distortion or buckling. 
Drainage is provided to prevent accumulation of water within the NFSF.
    New fuel shipping containers only carry two new fuel assemblies. 
The procedure used for new fuel receipt requires the use of the 
monorail auxiliary hoist on the cask handling crane for lifting 
operations. A special new fuel handling tool is required to be attached 
to the monorail auxiliary hoist to lift each fuel assembly from the 
shipping container. This new fuel handling tool can only be attached to 
the top nozzle of one fuel assembly at a time. The attached fuel 
assembly is moved to either the new fuel storage racks or the new fuel 
elevator if the assembly is going to be stored in the spent fuel 
facility. Both of these storage positions will only accommodate one 
fuel assembly in a designed location. Therefore, the design of the new 
fuel storage rack, the fuel handling equipment, and the administrative 
controls are such that subcriticality is assured under normal and 
accident conditions.
    The spent fuel pool is divided into two separate and distinct 
regions, which for the purpose of criticality considerations may be 
considered as separate pools. Region I, reserved for core offloading 
and new fuel storage, has the capacity for a minimum of 200 assemblies. 
Wolf Creek Technical Specification 5.6.1.1.a limits the enrichment of 
new fuel to 4.45 w/o U-235. The spent fuel pool is designed to store 
fuel in a geometric array that precludes criticality (keff 
no greater than 0.95), even in the event of complete loss of the 
soluble boron in the pool water. Fuel movements are procedurally 
controlled and designed to preclude conditions involving criticality 
concerns. Moreover, previous accident analyses have demonstrated that a 
fuel handling accident (i.e., a dropped fuel element) will not create 
conditions which exceed design specifications. In addition, the 
Technical Specifications and the Wolf Creek Final Safety Analysis 
Report specifically address the new fuel enrichment limits (4.45 w/o 
uranium-235), refueling operations and limit the handling of fuel to 
ensure against an accidental criticality and to preclude certain 
movements over the spent fuel pool and the reactor vessel.
    Notwithstanding the fact that procedures and controls prevent an 
inadvertent criticality during fuel handling, area radiation monitors, 
as described in Section 12.3.4 of the Wolf Creek UFSAR, are located 
near the spent fuel pool, new fuel storage vault, and cask handling 
area. These monitors are provided in accordance with GDC 63 and 10 CFR 
70.24 to serve as criticality alarm monitors, and they conform to the 
requirements of 10 CFR Part 70, Regulatory Guides 8.5 and 8.12, and 
Standards ANSI/ANS-8.3-1979 and USAS N2.3-1967. These monitors will 
remain in place and will continue to provide prompt warning of high 
radiation in the unlikely event of an inadvertent criticality accident.
    Workers qualified to work in radiologically-controlled areas are 
trained, as part of Plant Access Training, to immediately evacuate an 
area in which an area radiation monitor is alarming and to notify the 
control room following evacuation. Personnel currently qualified to 
respond to potential fuel handling accidents receive additional 
training, which directs them to identify the affected area, place fuel 
in a safe location, evacuate the affected area, and minimize the spread 
of airborne radiation.
    In summary, the training provided to personnel involved in fuel 
handling operations, the design of the fuel handling equipment, the 
administrative controls, the technical specifications on new and spent 
fuel handling and storage and the design of the new and spent fuel 
storage racks preclude inadvertent or accidental criticality.
    Based upon the information provided, there is reasonable assurance 
that irradiated and unirradiated fuel will remain subcritical. 
Furthermore, there is reasonable assurance that, should an inadvertent 
criticality occur, the licensee will detect such a criticality and 
workers will respond properly. Procedures, monitors, and training 
constitute good cause for granting an exemption to 10 CFR 70.24. In 
addition, the licensee has verified that a separate radiation 
monitoring system remains available to meet the requirements of 10 CFR 
Part 50, Appendix A, General

[[Page 35535]]

Design Criterion 63, to detect excessive radiation levels and to 
initiate appropriate safety actions in fuel storage and handling areas. 
Therefore, the staff concludes that the licensee's request for an 
exemption from the requirements of 10 CFR 70.24 is acceptable and 
should be granted.

III

    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 Wolf Creek Nuclear 
Operating Corporation an exemption as described in Section II above 
from 10 CFR 70.24, ``Criticality Accident Requirements.''
    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 (61 FR 9207).
    This exemption is effective upon issuance.

    For The Nuclear Regulatory Commission.

    Dated at Rockville, Maryland, this 24th day of June 1997.
Frank J. Miraglia,
Acting Director, Office of Nuclear Reactor Regulation.
[FR Doc. 97-17145 Filed 6-30-97; 8:45 am]
BILLING CODE 7590-01-P