1CAN128602, Proposed Tech Specs Deleting Requirements for Enrichment Limit for Reload Fuel Assemblies

Proposed Tech Specs Deleting Requirements for Enrichment Limit for Reload Fuel Assemblies

ML20215F615
Person / Time
Site:	Arkansas Nuclear
Issue date:	12/12/1986
From:	ARKANSAS POWER & LIGHT CO.
To:
Shared Package
ML20215F608	List: 1CAN128602, Proposed Tech Specs Deleting Requirements for Enrichment Limit for Reload Fuel Assemblies ML20215F605
References
1CAN128602, NUDOCS 8612240004
Download: ML20215F615 (5)

Text

J PROPOSED TECHNICAL SPECIFICATION CHANGE IN THE MATTER OF AMENDING LICENSE' NUMBER DPR-51 ARKANSAS POWER AND LIGHT COMPANY ARKANSAS NUCLEAR ONE - UNIT 1 DOCKET NUMBER 50-313 DECEMBER 12,~1986 I

i l

i.

~

i 8612240004 861212

! PDR ADOCK 05000313 PDR p

I 1CAN128692

PROPOSED CHANGE Change Specifications 5.3.1.6 and 5.3.1.4 (Page 114) as shown on the marked up copy attached to this transmittal.

DISCUSSION This proposed change relates to the requirements for the enrichment limit for reload fuel assemblies. The change is needed to decrease feed batch size (increase discharge burnup) for economic reasons. The request involves deletion of the reload fuel enrichment limit and, instead, specifies the use of low enrichment fuel while maintaining the design basis of the initial core loading. Exact specification of the initial enrichment for reload fuel assemblies is unnecessary and inconsistent with current reload analysis practices.

Although it is used in conjunction with a number of parameters and considerations in determining safe operation 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 measurable 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 for 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 amendment. These safety and operating limits assure fuel cladding integrity, reactor coolant system integrity, availability of sufficient instrumentation to provide automatic protective actions, acceptable core power distribution during power operation, core subcriticality after a reactor trip, and prevents the release of significant amounts of fission product activity. The Technical Specifications also specify limits for the enrichment of new fuel which will be stored in the spent fuel pool.

Remaining unchanged by the proposed amendment, those limits ensure that fuel in the pool will remain sufficiently subcritical.

Current reload practices for a given cycle requires a safety evaluation and Technical Specification change with respect to 10CFR50.59 and 50.90. Safety and operating limits are established and verified acceptable to the appropriate criteria, in accordance with NRC approved reload design methodology for ANO-1. The ANO-1 Reload Reports submitted for NRC review document the acceptance of key physics parameters to the appropriate criteria, the review of each SAR accident analysis, and assure that the transient evaluation of the reload cycle is bounded by previously accepted analysis.

ICAN128602

This proposed amendment also addresses a changa in Specification 5.3.1.4.

The active height of the core is currently 141.8 inches, not 144 inches.

Since this dimension may vary slightly from one reload to another, an approximate value of.142 inches is proposed for inclusion within the Technical Specifications. The specific assembly heights are identified and evaluated as a part of the core reload report. This change is only administrative in nature and, therefore, is of no significance'with respect to the health and safety of the public.

.+ l!

DETERMINATION OF SIGNIFICANT HAZARDS Arkansas Power and Light Company has performed an analysis of the proposed change in accordance with 10CFR90.91(a)(1) regarding no significant hazards consideration, using the standards'in 10CFR90.92(c).

A discussion of those standards as they relate to this amendment request follows:

Criterion 1 - Does not involve a significant~ increase in the probability or s consequences of an accident previously evaluated.

The proposed change would not increase the probability or consequences of any accident previously evaluated since the fuel enrichment is not a direct input to the reactor safety analysis and, therefore, would not affect previously analyzed accidents associated with plant operations.

Criterion 2 - Does not create the possibility of a new or different kind of accident from any previously evaluated.

The proposed change would not create the possibility of a new or different kind of accident from any previously analyzed since the current request does not address the actual enrichment currently utilized in the ANO-1 core; but, it merely deletes a numerical limitation for new fuel. A separate safety evaluation is required prior to the use of such reload fuel which will address specific enrichments.

, Criterion 3 - Does not involve a significant reduction in a margin of

, safety.

The proposed change would not involve a significant reduction in the margin of safety since the request does not in itself affect a Limiting Condition for Operation, a Safety Limit or a surveillance requirement required for current operation of the plant.

ICAN128602

a y

PROPOSED TECHNICAL SPECIFICATION CHANGES 1CAN128602

n 5.3 REACTOR Specification 5.3.1 Reactor Core 5.3.1.1 lhe reactor core contains approximately 93.1 metric tons of slightly enriched uranium dioxide pellets. The pellets are encapsulated in Zircaloy-4 tubing to form fuel rods. The reactor core is made up of 177 fuel assemblies. Each fuel assembly contains 208 fuel rods.(1,2) 5.3.1.2 The reactor core approximates a right circular cylinder with an equivalent diameter of 128.9 inches and an active height of approximately 142 inches.(2) l 5.3.1.3 The average enrichment of the initial core is a nominal 2.62 weight percent of 23su. Three fuel enrichments are used in the initial core. The highest enrichment is less than 3.5 weight percent 235U.

5.3.1.4 There are 60 full-length control rod assemblies (CRA) and 8 axial power shaping rod assemblies (APSRA) distributed in the reactor core as shown in FSAR Figure 3-59. The full-length CRA contain a 134-inch length of silver-indium-cadmium alloy clad with stainless steel. The APSRA contain a 36-inch length of silver-indium-cadmium alloy.(3) 5.3.1.5 The initial core has 68 burnable poison spider assemblies with similar dimensions as the full-length control rods. The cladding is Zircaloy-4 filled with alumina-boron and placed in the core as shown in FSAR Figure 3-2.

5.3.1.6 Reload fuel assemblies and rods shall conform to design and evaluation described in FSAR and shall be of low enrichment. l 5.3.2 Reactor Coolant System 5.3.2.1 The reactor coolant system is designed and constructed in accordance with code requirements.(4) 5.3.2.2 The -eactor coolant system and any connected auxiliary systems exposed to the reactor coolant conditions of temperature and pressure, are designed for a pressure of 2500 psig and a temperature of 650 F. The pressurizer and pressurizer surge line are designed for a temperature of 670 F.(5) 5.3.2.3 The reactor coolant system volume is less than 12,200 cubic feet.

Amendment No. 114