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

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