[Federal Register Volume 63, Number 133 (Monday, July 13, 1998)]
[Notices]
[Pages 37601-37605]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-18544]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-482]
Wolf Creek Nuclear Operating Corporation; Notice of Consideration
of Issuance of Amendment to Facility Operating License, Proposed No
Significant Hazards Consideration Determination, and Opportunity for a
Hearing
The U.S. Nuclear Regulatory Commission (the Commission) is
considering issuance of an amendment to Facility Operating License No.
NPF-42 issued to Wolf Creek Nuclear Operating Corporation (the
licensee) for operation of the Wolf Creek Nuclear Generating Station,
Unit No. 1 located in Coffey County, Kansas.
The proposed amendment would support a modification to the plant to
increase the storage capacity of the spent fuel pool and increase the
maximum nominal fuel enrichment to 5.0 nominal weight percent U-235.
Before issuance of the proposed license amendment, the Commission
will have made findings required by the Atomic Energy Act of 1954, as
amended (the Act) and the Commission's regulations.
The Commission has made a proposed determination that the amendment
request involves no significant hazards consideration. Under the
Commission's regulations in 10 CFR 50.92, this means that operation of
the facility in accordance with the proposed amendment would not (1)
involve a significant increase in the probability or consequences of an
accident previously evaluated; or (2) create the possibility of a new
or different kind of accident from any accident previously evaluated;
or (3) involve a significant reduction in a margin of safety. As
required by 10 CFR 50.91(a), the licensee has provided its analysis of
the issue of no significant
[[Page 37602]]
hazards consideration, which is presented below:
1. The proposed change does not involve a significant increase in
the probability or consequences of an accident previously evaluated.
In the analysis of the safety issues concerning the expanded Spent
Fuel Pool storage capacity, the following previously postulated
accident scenarios have been considered:
a. A spent fuel assembly drop in the Spent Fuel Pool
b. Loss of Spent Fuel Pool cooling flow
c. A seismic event
d. Misloaded fuel assembly
The probability that any of the accidents in the above list can
occur is not significantly increased by the modification itself. The
probabilities of a seismic event or loss of Spent Fuel Pool cooling
flow are not influenced by the proposed changes. The probabilities of
accidental fuel assembly drops or misloadings are primarily influenced
by the methods used to lift and move these loads. The method of
handling loads during normal plant operations is not significantly
changed, since the same equipment (i.e., Spent Fuel Pool Bridge Crane)
and procedures will be used. A new offset handling tool will be
required to assess some storage rack cells located adjacent to the pool
walls. The grapple mechanism, procedures, and fuel manipulation methods
will be very similar to those used by the spent fuel handling tool.
Therefore, this tool does not represent a significant change in the
methods used to lift or move fuel. Since the methods used to move loads
during normal operations remain nearly the same as those used
previously, there is no significant increase in the probability of an
accident.
During rack removal and installation, all work in the pool area
will be controlled and performed in strict accordance with specific
written procedures. Any movement of fuel assemblies required to be
performed to support the modification (e.g., removal and installation
of racks) will be performed in the same manner as during normal
refueling operations. Shipping cask movements will not be performed
during the modification period.
Accordingly, the proposed modification does not involve a
significant increase in the probability of an accident previously
evaluated.
The consequences of the previously postulated scenarios for an
accidental drop of a fuel assembly in the Spent Fuel Pool have been re-
evaluated for the proposed change. The results show that the postulated
accident of a fuel assembly striking the top of the storage racks will
not distort the racks sufficiently to impair their functionality. The
minimum subcriticality margin, Keff less than or equal to
0.95, will be maintained. The structural damage to the Fuel Building,
pool liner, and fuel assembly resulting from a fuel assembly drop
striking the pool floor or another assembly located within the racks is
primarily dependent on the mass of the falling object and the drop
height. Since these two parameters are not changed by the proposed
modification, the structural damage to these items remains unchanged.
Cycle specific calculations, using core specific parameters continue to
ensure that the radiological dose at the exclusion area boundary remain
within the limits documented in the WCGS [Wolf Creek Generating
Station] Updated Safety Analysis Report. Dose levels remain well within
the levels required by 10 CFR 100, paragraph 11, as defined in Section
15.7.4.II.1 of the Standard Review Plan. Thus, the results of the
postulated fuel drop accidents remain acceptable and do not represent a
significant increase in consequences from any of the same previously
evaluated accidents that have been reviewed and found acceptable by the
NRC.
The consequences of a loss of Spent Fuel Pool cooling have been
evaluated and found to have no increase. The concern with this accident
is a reduction of Spent Fuel Pool water inventory from bulk pool
boiling resulting in uncovering fuel assemblies. This situation would
lead to fuel failure and subsequent significant increase in offsite
dose. Loss of Spent Fuel Pool cooling at WCGS is mitigated in the usual
manner by ensuring that a sufficient time lapse exists between the loss
of forced cooling and uncovering fuel. This period of time is compared
against a reasonable period to re-establish cooling or supply an
alternative water source. Evaluation of this accident usually includes
determination of the time to boil. The time allowed for operator action
is much less than the onset of any significant increase in offsite
dose, since once boiling begins it would have to continue unchecked
until the Spent Fuel Pool surface was lowered to the point of exposing
active fuel. The time to boil represents the onset of loss of Spent
Fuel Pool water inventory and is commonly used as a gage for
establishing the comparison of consequences before and after a
refueling project. The heat up rate in the Spent Fuel Pool is a nearly
linear function of the fuel decay heat load. The fuel decay heat load
will increase subsequent to the proposed changes because of the
increase in the number [of] assemblies and higher fuel burnups. The
methodology used in the thermal-hydraulic analysis determined the
maximum fuel decay heat loads which are allowed by maintaining the
current time allowed for operator action (i.e., more than two hours to
boil during complete loss of forced cooling). Therefore, the allowed
operator action time remains unchanged from the previous design basis.
In the unlikely event that all Spent Fuel Pool cooling is lost,
sufficient time will still be available subsequent to the proposed
changes for the operators to provide alternate means of cooling before
the onset of pool boiling. Therefore, the proposed change represents no
increase in the consequences of loss of Spent Fuel Pool cooling.
The consequences of a design basis seismic event are not increased.
The consequences of this accident are evaluated on the basis of
subsequent fuel damage or compromise of the fuel storage or building
configurations leading to radiological or criticality concerns. The new
racks have been analyzed in their new configuration and found safe
during seismic motion. Fuel has been determined to remain intact and
the storage racks maintain the fuel and fixed poison configurations
subsequent to a seismic event. The structural capability of the pool
and liner will not be exceeded under the appropriate combinations of
dead weight, thermal, and seismic loads. The Fuel Building structure
will remain intact during a seismic event and will continue to
adequately support and protect the fuel racks, storage array, and pool
moderator/coolant. Thus, the consequences of a seismic event are not
increased.
Fuel misloading accidents were previously postulated occurrences.
The consequence of this type of accident has been analyzed for the
worst possible storage configuration subsequent to the proposed
modification and the consequences were found to be acceptable because
the reactivity in the Spent Fuel Pool remained below 0.95. After the
proposed modification, the worst case postulated accident condition,
for the Mixed Zone Three Region configuration, occurs when a fresh fuel
assembly of the highest possible enrichment is inadvertently loaded
into a Region 2 storage cell. Further, after the proposed modification,
the worst case postulated accident condition, for the checkerboard
configuration, occurs when a fresh fuel assembly of the highest
possible
[[Page 37603]]
enrichment is inadvertently loaded into an empty storage cell. In both
postulated accident scenarios, credit is allowed for soluble boron in
the water, and the Spent Fuel Pool reactivity is maintained below 0.95.
Therefore, there is no increase in consequences due to the
modification.
Therefore, it is concluded that the proposed changes do not
significantly increase the probability or consequences of any accident
previously evaluated.
2. The proposed change does not create the possibility of a new or
different kind of accident from any accident previously evaluated.
To assess the possibility of new or different kind of accidents, a
list of the important parameters required to ensure safe fuel storage
was established. Safe fuel storage is defined here as providing an
environment which would not present any significant threats to workers
or the general public. In other words, meeting the requirements of 10
CFR 100 and 10 CFR 20. Any new events which would modify these
parameters sufficiently to place them outside of the boundaries
analyzed for normal conditions and/or outside of the boundaries
previously considered for accidents would be considered a new or
different accident. The criticality and radiological safety evaluations
were reviewed to establish the list of important parameters. The fuel
configuration and the existence of the moderator/coolant were
identified as the only two parameters which were important to safe fuel
storage. Significant modification of these two parameters represents
the only possibility of an unsafe storage condition. Once the two
important parameters were established, an additional step was taken to
determine what events (which were not previously considered) could
result in changes to the storage configuration or moderator/coolant
presence during or subsequent to the proposed changes. This process was
adopted to ensure that the possibility of any new or different accident
scenario or event would be identified.
Due to the proposed changes, an accidental drop of a rack module
during construction activity in the pool was considered as the only
event which might represent a new or different kind of accident.
An installation accident of a rack dropping onto stored spent fuel
or the pool floor liner is not a postulated event due to the defense-
in-depth approach to be taken, as discussed in detail within Section
3.5 of the Licensing Report [Enclosure I to the March 20, 1998 letter].
This approach is similar to that taken previously for lifting a pool
gate with the Spent Fuel Pool Bridge Crane. A new temporary hoist and
rack lifting rig will be introduced to lift and suspend the racks from
the bridge of the Cask Handling Crane. These temporary lift items have
been designed in accordance with the requirements of NUREG-0612 and
ANSI N14.6 with respect to redundancy in load path or safety margin.
The postulated rack drop event is commonly referred to as a ``heavy
load drop'' over the pools. Heavy loads will not be allowed to travel
over any racks containing fuel assemblies, thus a rack drop onto fuel
is precluded. A rack drop to the pool liner is not a postulated event,
since all of the lifting components (except for the Cask Handling
Crane) either provide redundancy in load path or are designed with
safety margins greater than a factor of ten. Nevertheless, the analysis
of a rack dropping to the liner has been performed and shown to be
acceptable. However, the question of a new or different type of event
is answered by determining whether similar heavy loads have been
carried over the pool. As stated above, pool gates have been previously
lifted within the Spent Fuel Pool. The pool gate and the storage racks
are both designated as ``heavy loads'' and the safeguards taken to
preclude these accidents are similar. All movements of heavy loads over
the pool will comply with the applicable administrative controls and
guidelines (i.e., plant procedures, NUREG-0612, etc.) Therefore, the
rack drop does not represent a new or different kind of accident.
The proposed change does not alter the operating requirements of
the plant or of the equipment credited in the mitigation of the design
basis accidents. The proposed change does not affect any of the
important parameters required to ensure safe fuel storage. Therefore,
the potential for a new or previously unanalyzed accident is not
created.
3. The proposed change does not involve a significant reduction in
a margin of safety.
The function of the Spent Fuel Pool is to store the fuel assemblies
in a subcritical and coolable configuration through all environmental
and abnormal loadings, such as an earthquake or fuel assembly drop. The
new rack design must meet all applicable requirements for safe storage
and be functionally compatible with the Spent Fuel Pool.
WCNOC has addressed the safety issues related to the expanded pool
storage capacity in the following areas:
1. Material, mechanical and structural considerations
2. Nuclear criticality
3. Thermal-hydraulic and pool cooling
The mechanical, material, and structural designs of the new racks
have been reviewed in accordance with the applicable provisions of the
NRC Guidance entitled, ``Review and Acceptance of Spent Fuel Storage
and Handling Applications''. The rack materials used are compatible
with the spent fuel assemblies and the Spent Fuel Pool environment. The
design of the new racks preserves the proper margin of safety during
abnormal loads such as a dropped assembly and tensile loads from a
stuck assembly. It has been shown that such loads will not invalidate
the mechanical design and material selection to safely store fuel in a
coolable and subcritical configuration.
The methodology used in the criticality analysis of the expanded
Spent Fuel Pool meets the appropriate NRC guidelines and the ANSI
standards (GDC 62, NUREG-0800, Section 9.1.2, the ``OT Position for
Review and Acceptance of Spent Fuel Storage and Handling
Applications,'' Regulatory Guide 1.13, and ANSI ANS 8.17). The
criticality analysis for the Mixed Zone Three Region and/or
checkerboard configuration confirms that the Keff is
maintained less than 0.95 without credit for the soluble boron in the
Spent Fuel Pool. Calculations show that for the most severe accident
condition, a soluble boron concentration of 500 ppm boron, in addition
to the Boral contained in the racks, would be adequate to maintain the
Keff less than 0.95. In accordance with NRC guidelines, the
soluble boron in the Spent Fuel Pool may be credited in accident
conditions. A minimum boron concentration of 2000 parts-per-million
(ppm) is maintained in the Spent Fuel Pool. The soluble boron in the
Spent Fuel Pool will ensure that Keff is maintained
substantially less than the design limitations under all conditions.
The margin of safety for subcriticality is maintained by having the
neutron multiplication factor equal to, or less than, 0.95 under all
accident conditions, including uncertainties. This criterion is the
same as that used previously to establish criticality safety evaluation
acceptance and remains satisfied for all analyzed accidents.
The thermal-hydraulic and cooling evaluation of the pool
demonstrated that the pool can be maintained below the specified
thermal limits under the conditions of the maximum heat load and during
all credible accident sequences and seismic events. The bulk pool
temperature will not exceed 207 deg.F during the worst single failure
of a
[[Page 37604]]
cooling pump. Localized pool boiling is predicted to occur in the worst
single failure of a cooling pump in the hypothetical worst case storage
cell, immediately following the completion of a full-core discharge.
This cell is very conservatively modeled to contain the hottest spent
fuel assembly, with maximum flow resistance including 50% blockage of
both the inlet and outlet flow areas. However, bulk pool boiling will
not occur, nor will fuel cladding experience DNB [departure from
nucleate boiling] or excessive thermal stresses. The fuel will not
undergo any significant heat up after an accidental drop of a fuel
assembly on top of the rack blocking the flow path. A loss of cooling
to the pool will allow sufficient time (2 hours) for the operators to
intervene and line up alternate cooling paths and the means of
inventory make-up before the onset of pool boiling. Therefore the
allowed operator action time remains unchanged from the previous design
bases. In the unlikely event that all pool cooling is lost coincident
with the completion of a full-core discharge, sufficient time will
still be available subsequent to the proposed changes for the operators
to provide an alternate means of cooling before the onset of bulk pool
boiling. Therefore, the accepted margin of safety remains the same.
Thus, it is concluded that the changes do not involve a significant
reduction in the margin of safety.
The NRC staff has reviewed the licensee's analysis and, based on
this review, it appears that the three standards of 10 CFR 50.92(c) are
satisfied. Therefore, the NRC staff proposes to determine that the
amendment request involves no significant hazards consideration.
The Commission is seeking public comments on this proposed
determination. Any comments received within 30 days after the date of
publication of this notice will be considered in making any final
determination.
Normally, the Commission will not issue the amendment until the
expiration of the 30-day notice period. However, should circumstances
change during the notice period such that failure to act in a timely
way would result, for example, in derating or shutdown of the facility,
the Commission may issue the license amendment before the expiration of
the 30-day notice period, provided that its final determination is that
the amendment involves no significant hazards consideration. The final
determination will consider all public and State comments received.
Should the Commission take this action, it will publish in the Federal
Register a notice of issuance and provide for opportunity for a hearing
after issuance. The Commission expects that the need to take this
action will occur very infrequently.
Written comments may be submitted by mail to the Chief, Rules and
Directives Branch, Division of Administrative Services, Office of
Administration, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001, and should cite the publication date and page number of
this Federal Register notice. Written comments may also be delivered to
Room 6D59, Two White Flint North, 11545 Rockville Pike, Rockville,
Maryland, from 7:30 a.m. to 4:15 p.m. Federal workdays. Copies of
written comments received may be examined at the NRC Public Document
Room, the Gelman Building, 2120 L Street, NW., Washington, DC.
The filing of requests for hearing and petitions for leave to
intervene is discussed below.
By August 12, 1998, the licensee may file a request for a hearing
with respect to issuance of the amendment to the subject facility
operating license and any person whose interest may be affected by this
proceeding and who wishes to participate as a party in the proceeding
must file a written request for a hearing and a petition for leave to
intervene. Requests for a hearing and a petition for leave to intervene
shall be filed in accordance with the Commission's ``Rules of Practice
for Domestic Licensing Proceedings'' in 10 CFR Part 2. Interested
persons should consult a current copy of 10 CFR 2.714 which is
available at the Commission's Public Document Room, the Gelman
Building, 2120 L Street, NW., Washington, DC, and at the local public
document room located at the Emporia State University, William Allen
White Library, 1200 Commercial Street, Emporia, Kansas 66801 and
Washburn University School of Law Library, Topeka, Kansas 66621. If a
request for a hearing or petition for leave to intervene is filed by
the above date, the Commission or an Atomic Safety and Licensing Board,
designated by the Commission or by the Chairman of the Atomic Safety
and Licensing Board Panel, will rule on the request and/or petition;
and the Secretary or the designated Atomic Safety and Licensing Board
will issue a notice of hearing or an appropriate order.
As required by 10 CFR 2.714, a petition for leave to intervene
shall set forth with particularity the interest of the petitioner in
the proceeding, and how that interest may be affected by the results of
the proceeding. The petition should specifically explain the reasons
why intervention should be permitted with particular reference to the
following factors: (1) the nature of the petitioner's right under the
Act to be made party to the proceeding; (2) the nature and extent of
the petitioner's property, financial, or other interest in the
proceeding; and (3) the possible effect of any order which may be
entered in the proceeding on the petitioner's interest. The petition
should also identify the specific aspect(s) of the subject matter of
the proceeding as to which petitioner wishes to intervene. Any person
who has filed a petition for leave to intervene or who has been
admitted as a party may amend the petition without requesting leave of
the Board up to 15 days prior to the first prehearing conference
scheduled in the proceeding, but such an amended petition must satisfy
the specificity requirements described above.
Not later than 15 days prior to the first prehearing conference
scheduled in the proceeding, a petitioner shall file a supplement to
the petition to intervene which must include a list of the contentions
which are sought to be litigated in the matter. Each contention must
consist of a specific statement of the issue of law or fact to be
raised or controverted. In addition, the petitioner shall provide a
brief explanation of the bases of the contention and a concise
statement of the alleged facts or expert opinion which support the
contention and on which the petitioner intends to rely in proving the
contention at the hearing. The petitioner must also provide references
to those specific sources and documents of which the petitioner is
aware and on which the petitioner intends to rely to establish those
facts or expert opinion. Petitioner must provide sufficient information
to show that a genuine dispute exists with the applicant on a material
issue of law or fact. Contentions shall be limited to matters within
the scope of the amendment under consideration. The contention must be
one which, if proven, would entitle the petitioner to relief. A
petitioner who fails to file such a supplement which satisfies these
requirements with respect to at least one contention will not be
permitted to participate as a party.
Those permitted to intervene become parties to the proceeding,
subject to any limitations in the order granting leave to intervene,
and have the opportunity to participate fully in the conduct of the
hearing, including the opportunity to present evidence and cross-
examine witnesses.
[[Page 37605]]
If a hearing is requested, the Commission will make a final
determination on the issue of no significant hazards consideration. The
final determination will serve to decide when the hearing is held.
If the final determination is that the amendment request involves
no significant hazards consideration, the Commission may issue the
amendment and make it immediately effective, notwithstanding the
request for a hearing. Any hearing held would take place after issuance
of the amendment.
If the final determination is that the amendment request involves a
significant hazards consideration, any hearing held would take place
before the issuance of any amendment.
A request for a hearing or a petition for leave to intervene must
be filed with the Secretary of the Commission, U.S. Nuclear Regulatory
Commission, Washington, DC 20555-0001, Attention: Rulemakings and
Adjudications Staff, or may be delivered to the Commission's Public
Document Room, the Gelman Building, 2120 L Street, NW., Washington, DC,
by the above date. A copy of the petition should also be sent to the
Office of the General Counsel, U.S. Nuclear Regulatory Commission,
Washington, DC 20555-0001, and to Jay Silberg, Esq., Shaw, Pittman,
Potts and Trowbridge, 2300 N Street, N.W., Washington, D.C. 20037,
attorney for the licensee.
Nontimely filings of petitions for leave to intervene, amended
petitions, supplemental petitions and/or requests for hearing will not
be entertained absent a determination by the Commission, the presiding
officer or the presiding Atomic Safety and Licensing Board that the
petition and/or request should be granted based upon a balancing of the
factors specified in 10 CFR 2.714(a)(1)(i)-(v) and 2.714(d).
The Commission hereby provides notice that this is a proceeding on
an application for a license amendment falling within the scope of
Section 134 of the Nuclear Waste Policy Act of 1982 (NWPA), 42 U.S.C.
10154. Under Section 134 of the NWPA, the Commission, at the request of
any party to the proceeding, must use hybrid hearing procedures with
respect to ``any matter which the Commission determines to be in
controversy among the parties.'' The hybrid procedures in Section 134
provide for oral argument on matters in controversy, preceded by
discovery under the Commission's rules, and the designation, following
argument, of only those factual issues that involve a genuine and
substantial dispute, together with any remaining questions of law, to
be resolved in an adjudicatory hearing. Actual adjudicatory hearings
are to be held on only those issues found to meet the criteria of
Section 134 and set for hearing after oral argument.
The Commission's rules implementing Section 134 of the NWPA are
found in 10 CFR Part 2, Subpart K, ``Hybrid Hearing Procedures for
Expansion of Spent Nuclear Fuel Storage Capacity at Civilian Nuclear
Power Reactors'' (published at 50 FR 41670, October 15, 1985) to 10 CFR
2.1101 et seq. Under those rules, any party to the proceeding may
invoke the hybrid hearing procedures by filing with the presiding
officer a written request for oral argument under 10 CFR 2.1109. To be
timely, the request must be filed within 10 days of an order granting a
request for hearing or petition to intervene. (As outlined above, the
Commission's rules in 10 CFR Part 2, Subpart G, and 2.714 in
particular, continue to govern the filing of requests for a hearing or
petitions to intervene, as well as the admission of contentions.) The
presiding officer shall grant a timely request for oral argument. The
presiding officer may grant an untimely request for oral argument only
upon showing of good cause by the requesting party for the failure to
file on time and after providing the other parties an opportunity to
respond to the untimely request. If the presiding officer grants a
request for oral argument, any hearing held on the application shall be
conducted in accordance with the hybrid hearing procedures. In essence,
those procedures limit the time available for discovery and require
that an oral argument be held to determine whether any contentions must
be resolved in adjudicatory hearing. If no party to the proceedings
requests oral argument, or if all untimely requests for oral argument
are denied, then the usual procedures in 10 CFR Part 2, Subpart G,
apply.
For further details with respect to this action, see the
application for amendment dated March 20, 1998, as supplemented by
letter dated May 28, 1998, which is available for public inspection at
the Commission's Public Document Room, the Gelman Building, 2120 L
Street, NW., Washington, DC, and at the local public document room
located at the Emporia State University, William Allen White Library,
1200 Commercial Street, Emporia, Kansas 66801 and Washburn University
School of Law Library, Topeka, Kansas 66621.
Dated at Rockville, Maryland, this 7th day of July 1998.
For the Nuclear Regulatory Commission.
Kristine M. Thomas,
Project Manager, Project Directorate IV-2, Division of Reactor Projects
III/IV, Office of Nuclear Reactor Regulation.
[FR Doc. 98-18544 Filed 7-10-98; 8:45 am]
BILLING CODE 7590-01-P
