1CAN069108, Application for Amend to License DPR-51,changing TS 5.3.1.6 & 5.4.1.1 to Increase Max Allowable Enrichment for New Fuel Being Cycled Through Facility from 3.5 to 4.1 Weight % U-235.Criticality Analysis Encl
| ML20076B330 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 06/27/1991 |
| From: | Carns N ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20076B333 | List: |
| References | |
| 1CAN069108, 1CAN69108, NUDOCS 9107110170 | |
| Download: ML20076B330 (8) | |
Text
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June 27, 1991 1CAN069108 U. S. Nuclear Regulatory Commission Document Control Desk c
Hall Station F1-137 Washington, DC 20555 SUllJECT:
Arkansas Nucinar One - Unit 1 Docket No. 50-313 l
bicenso No. DPR-51 Proposed Chango to the Technical Specification i
inctnaned Fresh Fuel Enrichment Gentlemen:-
Entergy Operations has-identified proposed changns to the Arkansas Nuclear Ono, Unit 1 (ANO-1) Technical Specifications 5.3.1.6 and 5.4.1.1.
These proposed changes increase the maximum allowable enrichment for new fuel being cycled through the facility from 3.5 to 4.1 weightc percent U-235.
These changes are needed for economic reasons to provido an increased cycle-energy while maintaining the feed batch size to a reasonable number of assemblies. Additionally, "2350" is being corrected to "U-235".
The request for the change to Specification 5.4.1.1 is supported by the enclosed Entergy Operations' report, " Criticality Analysis of ANO-1 Fresh Fuel Rack, December 1990".
Operation with increased enrichment will bo addressed in subsequent required reload analyses when required.-
The proposed changes have been evalunted in accordance with 10CFR50.91(a)(1), using the criteria in 10CFR50.92(c) and it has been determined that this request involves no significant hazards considerations. The basis for this determinat ion is included in the enclosed submitta1.
The-circumstances of this request are not exigent or emergency.
llowever, wn would appreciato a prompt review to allow for futurn roload design flexibility.
We request that the effective dato for_ this change be 30 days af ter NRC issuance of the amendment to allow for distribution of the amendment and procedural revisions necessary to implement the changes.
- Very truly yours, 40 g 41 C--
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Attachment I\\ \\
9107110170 910627
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s U. S.1:RC June 27, 1991 j
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Mr. Robert Hartin U. S. Nuclear Regulatory Commission Region IV 611 Ryan_ Plaza Drive, Suite 1000 Arlington, TX 76011 NRC Senior Resident inspector Arkansan Nuclear One - AND-1 6 2 Number 1, Nucinar Plant Road i
Russellville, AR 72801 Mr. Thomas W. Alexion j
NRR Project Hannger, Region IV/ANO-1 j
U. S. Nuclear Regulatory Commission i
NRR Hall Stop 11-D-23 l
One White Flint North
-11555-Rockv111e Pike l
Rockville, Maryland 20852 Hs. Shori R. Peterson NFR Project Manager, Region IV/ANO-2 U..S. Nuclear Regulatory-Commension NRR Hall Stop 11-D-23 One White Flint North 11555 Rockville Piko Rockvillo, Maryland 20852 Hs. Greta D1cus, Director Division of Radiation Control and Emergency Management Arkansas Department of Ilealth 4815 West Markham Street Little Rock, AR 72201 s
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STATE OF ARKANSAd
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OATil I, J. W. Yelverton, being duly sworn, subscribe to and say that I am General Manager, Plant Operatinns ANO for Entergy Operations, Inc.;
that I have full authority to execute this oath; that I have road the document numbered ICAN069108 and know the contents thereof; and that to the best of my knowledge, information and belief the statements in it arm true.
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/J. W. [elverto.1 St!BSCRISED AND SWORN TO me, a Notary Public in and for the County and State above named, this M M day of df,/rtZt>
1991.
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PROPOSED TECHNICAL SPECIFICATION CHANGE AND RESPECTIVE SAFETY ANALYSIS i-IN THE MATTER OF A'12NDING:
LICENSE NO. DPR-51 ENTERGY OPF. RATIONS, INC.
ARKANSAS NUCLEAR ONE,-UNIT l' DOCKET NO. 50-313 h
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PROPOSED CHANGE l
The proposed changes will amend Specification 5.3.1.6, " Reactor Core",
and 5.4.1.1, "New Fuel Storage", to increase the maximum enrichment of future reload fuel being cycled through the facility from 3.5 to 4.1 weight percent U-235.
Specification 5.4.1.1 is also being revised to delineate the allowable storage positions in the fresh fuel rack.
Additionally, "235U" is being corrected to "U-235" on this page.
DISCUSSION The proposed changes relate to the requirements for the enrichment limit of reload fuel assemblies. The changes are needed for economic reasons to provide an increased cycle energy while maintaining feed batch size.
The changes involve an increase in the maximum allowable enrichment of fual being cycled through the facility from 3.5 to 4.1 weight percent U-235.
In letter DCAN028302 (dated February 17, 1983), Arkansas Power & Light (AP&L) submitted a Technical Specification change request to allow operations with the proposed expansion of the spent fuel pool capacit;.
This submittal also included the request to increase the enrichment o the fuel assemblies to 4.1 weight percent U-235 In a "0CAN048312, Forwards Vols 1-3 to Arkansas Nuclear One Units 1 & 2 Response to Suppl 1 to NUREG-0737 Requirements for Emergency Response Capability,Generic Ltr 82-33, Per [[CFR" contains a listed "[" character as part of the property label and has therefore been classified as invalid.. Task Force Formed & Organizational Structure Established|letter dated April 15, 1983]], the NRC issued Amendment 76 to the ANO-1 Technical Specifications which approved the Technical Specifications proposed in the February 17, 1983, AP&L's letter.
In the Safety Evaluation associated with Amendment 76, the Staff concluded thet any number of fuel assemblies of the Babcock & Wilcox (B & W) 15 x 15 design having enrichments no greater than 4.1 weight percent U-235 may be stored in Regions 1 and 2 of the ANO-1 spent fuel pool.
Subsequent to the receipt of the Safety Evaluation, it was noted that we had inadvertently failed to propose to change the enrichment limit for new (reload) fuel listed in Specification 5.3.1.6.
In letter ICAN128602 (dated De.9mber 12, 1986) AP&L submitted a Technical Specification change res;est to delete the specification of the maximum enrichment limit for reloaa fuel and specify in its place the use of low enrichment fuel while maintaining the design basis of the initial core loading.
In April 1989, in an effort to clear the back log of outstanding Technical Specification changes under consideration by the NRC Staff, AP&L was questioned by the NRR Project Manager pertaining to the immediate need for the December 12, 1986 submittal.
As it was not deemed essential at the time it was mutually agreed to consider the request withdrawn.
To make the maximum allowable enrichment level for reload fuel (Speci fication 5. 3.1. 6) consistent with the enrichment limits for new fuel which can be stored in the spent fuel poc1, Entergy Operations is also proposing to change Specification 5.3.1.6.
Current practice is to store the new fuel, after receipt inspection, in the~ spent fuel pool, llowever, to be consistent in storage evaluations, we are requesting Specification 5.4.1.1 be changed.
The-scope of the request for Specification 5.4.1,1 is limited to the handling and storage of fuel with 4.1 or less weight percent enrichment. The current Specification 5.4.1 1 limits the maximum enrichment of-fuel to an enrichment of 3.5 weight percent of U-235.
ANO-1 is planning to begin transitioning to a higher energy fuel cycle beginning with Cycle 11.
To accomplish this plan, Entergy Operations proposes to increase the maximum allowed initial enrichment for fuel up to of 4.1 weight percent U-235._ The fuel bundles currently being procured for ANO-1 are the B &
W supplied MK-B8.
The design of these fuel bundles is not affected by these proposed changes.
Althouhh it is used in conjunction with a number of parameters and considerations in-determining safe operat!on of the reactor core, the fuel enrichment is not a direct input to the reactor safety analysis.
The fuel enrichment, number of fuel assemblies, exposure (burnup) of existing fuel, burnable poisons and fuel management schemes-are used to derive measurabic reactor core parameters important to safe operation.
These dynamic parameters, rod worths and peaking factors are currently included in the ANO-1 Technical Specifications.
The specification of fuel enrichment in the core design section alone does not uniquely determine nor limit the values of the reactor core parameters which are important to safe operation.
The existing safety limits and limiting conditions for operation (LCOs) as' established in the Technical Specifications will not be changed by the proposed changes, These safety and operating limits assure fuel cladding intogrity, reactor coolant syriem integrity,~ availability of sufficient instrumentation to provide zatomatic protective actions, acceptable core power distribution during power operation, core cuberiticelity after a reactor trip, and prevents the release of significant amounts of fission product activity.
The fuel. loading errors pellets, rod, and assembly, which were discussed in the FSAR presented example cases using enrichments up to 3.40 weight percent and stated "the enrichments analyzed are conservative and the-gr(atest possible enrichments." Even though these enrichments.were the highest planned at that time (1972), this was not intended to invalidate the statements pertaining to fuel misicadings with' fuel of higher enrichment for the following-reasons:
(1) As currently noted in the ANO-1 SAR, the incore instrumentation is designed to detect _the occurrence of gross core loading errors by observing power distribution anomalies during startup physics testing.
A wider range of fuel enrichments, lump burnable poison concentration, 'and burnup would result _ in an equal or higher probability of the detections of a power distribution change from a core loading error.
(2) Strict administrative controls during fabrication prevent pellet or rod enrichment loading errors et the fabrication tNcility as currently stated in the ANO-1 SAR.
7 Current reload practicos for a given cyclo require a safety evaluation and Technical Specification change with respect to 10 PVR 50.59 and 50.90.
Safety and_ operating limits are established and verified ac optable to the appropriato critoria, in accordance with NRC approved reload design methodology for ANO-1.
The ANO-1 Roload Reports document the acceptance of key physics paramotors to the appropriato criteria, e
the review of each SAR accident analysis and e
the assurance that the transient evaluation of the roload cycle is bounded by previously accepted analysis.
Entorgy Operations also requests the addition of Figure 5.4-1 to Technical Specification 5.4.1.1 to indicato the locations in the Fresh Fuel Storago-Rack that will be prohibited from uso.
Thoso locations are prohibited to maintain k-of fectivo below 0.98 with an optimum moderat ion as required by NUREG-0800, Section 9.1.1.
This is demonstrated in tho 1
attached criticality analysis (At.tachment 1).
DETERMINATION OF SIGNIFICANT HAZARDS In accordance with 10 GFR 50.92, Entorgy Operations has ovaluated whether the proposed changos involves a significant nafety hazards consideration. The following discussion for the proposed change to Specification 5.4.1.1 is limited to the fuel storage and handling accident scenarios since the impact of core onrichment upon operational safety margins is an integral part of each reload analysis.
Entergy Operati ns has concluded that the proposed changes to Techvital Specifications 5.3.1.6 and 5.4.1.1 do not involve a significant hazards consideration because the operation of Arkansas Nuclear One, Unit 1 in i
accordanco with those changes would not:
(1) Involve a significant increase in the probability or consequences of an acci<1ent previously ovaluated.
Tho propased changes will not significantly increase the probability or consequences of any accident previously evaluated since the offect of increasing fuol enrichment is included in the calculation of mnasurable core paramotors each reload cycle and
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th er,o, in turn, are reviewed to ensure adequate margins for safo poration and conformanco to t.ho safety limits and LCOs established c
by Technical Specifications are mot.
The fission product inventory contained in the fuel is a function of burnup, not enrichment, so the consequences of postulated accident releases are unchanged.
The fuel loading errors originally addressed in the FSAR have boon reviewed and the statements mado continuo to be valid for thn higher 4.1 wolght porcent onrichment, Gross coro loading errorg would be detected with an equal or higher probability and tho strict administrativo controin used to prevent pollet and rod enrichment errors continue to romain in effect.
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Fresh fuel-handling accidents remain bounded by the original FSAR i
analysis.- The only accident scenarios for which the probability of occurrence are affected by fuel enrichment involve criticality events during fuel handling and storage. The enclosed criticality analysis demonstrates that the calculated k-ef fective, during fuel hsndling and storage, is adequate to ensure subcriticality for all defined accident conditions.
Since subcriticality is maintained, no releases result f rom the above fuct handling criticalit y accident scenario.
(2) Create the possibility of a new or dif ferent kind of accident from any previously evaluated.
The proposed changes will not create the possibility of a new or different kind of accident from any previously analyzed since the current request does not addtess the actual enrichment currently utilized in the ANO-1 core; but merely changes the maximum allowable enrichment limit for new fuel. A separate safety evaluation is required priot to the use of such reload fuel which will address specific enrichments. The possibility of loading assemblies.into the prohibited spaces in the Fresh Fuel Storage Rack will be prevented by physical blockage of these spaces prior to any fuel storage in the Rack.
It should be noted that if these spaces were not blocked through error and if the rack was fully loaded, then inadvertant criticality would still not occur until foam of the appropriate density was introduced into the racks.
(3) Involve a significant reduction in the margin of safety.
The proposed enrichment increase may cause an increase in future fresh fuel reactivity but it will not change or reduce the related margins of safety, such as the Limiting Condition for Operation which requires maintaining a 1% Ak/k shutdown margin or the Safety Limits on DNBR or allowable power peaking.
The enclosed criticality analysis demonstrates that there is adequate margin to ensure subcriticality of the new fuel during storage and handling operations.
Therefore, based on the evaluation discussed above, Entergy Operations has concluded that the proposed changes do not involve a significant hazards consideration.