ML20238F105

Application for Amend to License DPR-79,revising TS to Provide for Insertion of Limited Number of Lead Test Assemblies,Beginning W/Unit 2 Operating Cycle 10 Core

ML20238F105
Person / Time
Site:	Sequoyah
Issue date:	08/27/1998
From:	Salas P TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20238F107	List: ML20238F105 ML20238F109
References
TVA-SQN-TS-98, TVA-SQN-TS-98-0, NUDOCS 9809030114
Download: ML20238F105 (8)

Text

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Tennessee Va!Iey Authority, Post Office Box 2000, Sodd/-Daisy, Temessee 37379 2000 August 27, 1998 TVA-SON-TS-98-04 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN:- Document Control Desk  !

Washington, D. C. 20555 '

Gentlemen:

In the Matter of ) Docket No. 50-328 Tennessee Valley Authority ) l l

SEQUOYAH NUCLEAR PLANT (SQN) - UNIT 2 - TECHNICAL SPECIFICATION (TS) CHANGE NO. 98-04, " INSERTION OF LEAD TEST ASSEMBLIES INTO THE UNIT 2 CORE" In accordance with the provisions of 10 CFR 50.4 and 50.90, TVA is submitting a request for an amendment to SON's licenses DPR-79 to change the TSs for Unit 2. The proposed  !

i change revises the current SON Unit 2 TSs to provide for insertion of a limited number of lead test assemblies, beginning with the Unit 2 operating Cycle 10 core. The lead test assemblies are described in the topical report submitted on August 7, 1998. The purpose of the lead test assembly topical report was to demonstrate that core designs using the reprocessed material will meet all operational, design, and safety criteria. The report also describes the cycle specific operating margins, power peaking margins, and

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! specific comparisons with and without LTAs for the Sequoyah Unit 2, cycle 10 core design. The operating margins for future cycles will be determined on a cycle specific basis. /

TVA has determined that there are no significant hazards considerations associated with the proposed change and that the change is exempt from environmental review pursuant to no the provisions of 10 CFR 51.22 (c) (9) . The SON Plant f 9809030114 980827 PDR ADOCK 05000328 P pg em.n - m-

U.S. Nuclear Regulatory Commission Page 2 August 27, 1998 l

l Operations Review Committee and the SQN Nuclear Safety Review Board have reviewed this proposed change and determined that operation of SON Unit 2, in accordance with the proposed change, will not endanger the health and safety of the public. Additionally, in accordance with 10 CFR 50.91(b) (1),

TVA is sending a copy of this letter to the Tennessee State Department of Public Health.

Enclosure 1 to this letter provides the description and evaluation of the proposed change. This includes TVA's determination that the proposed change does not involve a significant hazards consideration, and is exempt from environmental review. Enclosure 2 contains copies of the appropriate TS pages from Unit 2 marked-up to show the proposed change. Enclosure 3 forwards the revised TS pages for Unit 2 which incorporate the proposed change.

TVA requests that NRC approve this TS change by March 1999 to support the Unit 2 Cycle 9 refueling outage presently scheduled to begin in April 1999.

TVA requests that the revised TS be made effective within 45 days of NRC approval. If you have any questions about this change, please telephone me at (423) 843-7170 or J. D. Smith at (423) 843-6672.

Sincerel ,

/ Pe o Salas Licensing and Industry Affairs Manager efore e this 27dand Subscribed daysworn of toj/b9

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un y lD$ AN Notaff 90blic 7- l

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My Commission Expires October 21, 1998 Enclosures cc: See page 3

U.S. Nuclear Regulatory Commission Page 3 August 27, 1998 cc (Enclosures):

Mr. R. W. Hernan, Project Manager Nuclear Regulatory Commission (

One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 Mr. Michael H. Mobley, Director (w/o Enclosures)

Division of Radiological Health \

Third Floor L&C Annex 401 Church Street Nashville, Tennessee 37243-1532 NRC Resident Sequoyah Nuclear Plant 260C Igou Ferry Road Soddy-Daisy, Tennessee 37379-3624 Regional Administrator U.S. Nuclear Regulatory Commission Region II Atlanta Federal Center 61 Forsyth St., SW, suite 23T85 Atlanta, Georgia 30303-3415

! ENCLOSURE 1 l

TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN) l UNIT 2 DOCKET NO. 328 PROPOSED TECHNICAL SPECIFICATION (TS) CHANGE TS-98-04 l DESCRIPTION AND EVALUATION OF THE PROPOSED CHANGE j i

I. DESCRIPTION OF THE PROPOSED CHANGE A change is requested to the current SON Unit 2 TSs to l provide for insertion of a limited number of lead test assemblies (LTAs), beginning with the Unit 2 operating Cycle 10 core. The lead test assemblies are described in '

Framatome Cogema Fuels (FCF) Report BAW-2328 included as.

part of the topical report submitted on August 7, 1998.

The specific change is described below:

Current Unit 2 TS page 5-4 In Paragraph 5.3.1, an additional sentence will be added to existing text as follows: "Sequoyah is authorized to place a limited number of lead test -

assemblies into the reactor, as described in the Framatome Cogema Fuels Report BAW-2328, beginning with i the Unit 2 operating Cycle 10 core."

II. REASON FOR THE PROPOSED CHANGE The purpose of placing the LTAs in the SON Unit 2 core is to verify that the effect of the LTAs on the core reactivity and power distributions are accurately calculated for a commercial light water reactor. This will ensure that the analytical methods that predict the behavior of LTAs are as accurate as the current methods used for predicting the behavior of enriched uranium fuel assemblies derived from natural uranium. j III.- SAFETY ANALYSIS l

The proposed change is justified based on detailed evaluations and analyses performed by TVA and FCF as described in the topical report submitted to the staff on August 7, 1998. The topical report provided the Blended Uranium Lead Test Assembly Design Report (BAW-2328) prepared by FCF, the ORNL Chemical and Isotopic Analysis prepared by Oak Ridge National Labs, and the TVA Lead Test El-1

i Assembly Performance Monitoring Plan. The evaluations and analyses were based on plant parameters taken from the SON Final Safety Analysis Report (FSAR). Except where noted

-otherwise, the data and evaluations provided in the topical L report were based upon the design and operational practices L of SON, and they are considered to be bounding.

l The potential effects of the LTAs on plant operations and safety have been evaluated in the Blended Uranium Lead Test Assembly Design Report (BAW-2328). Section 2.1.1 provides a comparison between the LTAs and the standard Mark-BW fuel assembly. Section 2.1.2 compares the LTA fuel pellets with the Mark-BW fuel pellets. The isotopic contents and chemical contaminant differences, manufacturing processes, mechanical properties, and material properties are addressed. The specifications for the two pellets are essentially the same. The manufacturing processes for the two pellets are the same. The mechanical and material properties of the LTA pellets are identical to those of the standard 002 pellets. Section 2.1.3 provides the fuel rod design and performance evaluation and concludes that the design limits are equal for both types of fuel. {

The nuclear design is provided in Section 2.2.

Section 2.2.1 discusses the neutronic model and its applicability to the LTA fuel. Section 2.2.2 is an assessment of the reactivity penalty associated with using blended uranium. Section 2.2.3 includes a comparison of fuel cycles with and without the LTAs and shows that the LTAs will not be the limiting assemblies in the core.

Section 2.2.4 quantifies the effects of the LTAs on safety parameters and shows that there is no safety concern.

Section 2.3 provides the thermal and hydraulic evaluation {

and concludes that these areas are not impacted by the use of the LTAs.

Section 3.0 provides the evaluation of FSAR Chapter 15 events. Both loss-of-coolant accident (LOCA) and non-LOCA events are evaluated. The LOCA evaluation in Section 3.1 concludes that the LOCA limits for standard uranium are equally applicable to the blended uranium fuel.

Section 3.2 provides the evaluation for all the events included in Regulatory Guide 1.70 and concludes that the LTAs will not cause a reduction to relevant acceptance criteria for all transients. Section 3.3 compares the radiological consequences for the LTAs and the Mark-BW fuel l and concludes that the current analyses are bounding and I that there is no increase in consequences for any design basis accident described in the FSAR. The criticality safety of the LTAs is assessed in Section 3.4, which shows that there is no loss in safety margin associated with their use.

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Section 4.0 is the operating margins evaluation. This evaluation demonstrates that the LTAs will not be the

, limiting assemblies and will not have any adverse effect on the core operating limits.

Section 5.0 discusses fuel handling considerations.

Section 6.0 provides the overall conclusion of the design report: the introduction of the LTAs will not have any adverse impact on the plant during the cycles in which they are inserted and does not constitute a significant difference from standard uranium assemblies.

Based on a review of the existing FSAR analyses and the information supplied FCF design report, it is concluded that the LTAs can be safely used in Sequoyah Unit 2.

IV. NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION TVA has concluded that operation of SON Unit 2, in accordance with the proposed change to the technical specifications [or operating license (s)], does not involve a significant hazards consideration. TVA's conclusion is based on its evaluation, in accordance with 10 CFR 50. 91 (a) (1) , of the three standards set forth in 10 CFR 50.92(c).

A. The proposed amendment does not involve a significant increase in the probability or consequences of an

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accident previously evaluated.

The LTAs are identical to the other Mark-BW fuel assemblies with the exception of minor differences internal to the fuel rods. These differences will not adversely affect reactor neutronic or thermal-hydraulic performance; therefore, they do not significantly increase the probability of accidents while in the reactor. The reload design analyses performed for SON Unit 2 Cycle 10 accounts for any minor neutronic differences of the LTAs and confirms any effects on the reload core to be within established fuel design limits.

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The pressure and temperature safety limits for the I

cycles in which the LTAs will be in the core are the same as those for the current operating cycle thus ensuring that the fuel will be maintained within the same range of safety parameters that form the basis for the FSAR accident evaluation. The potential effects of the LTAs on plant operation and safety have been evaluated. This evaluation investigated both LOCA and non-LOCA events, and concluded that the current analyses remain bounding and that there will l El-3

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be no increase in the probability of occurrence for any design basis accident described in the FSAR.

The impact of the LTAs on key safety analysis parameters was examined and it was concluded that there will be an insignificant impact.

The impacts of the LTAs on the radiological consequences for all postulated events have been evaluated. The total calculated source term and the source term-activity of isotopes, which significantly contribute to operator and off-site accident exposure levels, were shown to be less than standard fuel assemblies, therefore, it will not increase the consequences of any accident previously evaluated.

B. The proposed amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated.

The fuel assembly design for the LTAs is identical to the standard fuel assemblies. The main difference between the LTAs and the production fuel is that the concentration of the U 234 and U 236 isotopes will be higher in the LTA fuel pellets than that typically l found in standard fuel. These isotopic. differences j will not affect the chemical, mechanical or thermal '

properties of the fuel pellet.

The LTAs meet the same design criteria and licensing basis criteria as the standard fuel assemblies and were. manufactured with the same processes. The LTA skeleton is identical to the standard skeleton, which ensures that the loadings associated with normal operation, seismic events, LOCA events, and shipping and handling are not affected.

Pressure and temperature safety limits will be maintained the same as those for the current operating cycle, thus ensuring that the fuel will be maintained within the same. range of safety parameters that form the basis for previous accident evaluations. No new performance requirements are being imposed on any system or component that exceed design criteria or l cause the core to operate in excess of design basis l

operating limits. No credible scenario has been L identified, which could jeopardize equipment that could cause intensify or mitigate events or accident sequences. Therefore, the LTAs will not create the possibility of accidents or equipment malfunctions of a different type than previously evaluated while in the reactor.

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C. The proposed amendment does not involve a significant reduction in a margin of safety.

The LTAs will not adversely affect reactor neutronic or thermal-hydraulic performance. The LOCA acceptance criteria with LTAs installed in the core will continue to be met: peak cladding temperature of 5 2200 *F, peak cladding oxidation of 5 17 percent, average clad oxidation of 5 1 percent, and long-term coolability.

The acceptance criteria for departure from nucleate boiling (DNB) events with the LTAs installed in the core will also continue to be met: 95 percent probability and 95 percent confidence interval that DNB is not occurring during the transient. Other acceptance criteria have also been demonstrated to remain within acceptable limits. The total calculated source term-activity and the source term-activity of isotopes, which significantly contribute to operator and off-site accident exposure levels of the LTAs, was determined to be less than that for the standard fuel assembly. All previously' evaluated events remain bounding and valid. For these reasons, the proposed amendment does not involve a significant reduction in a margin of safety.

V. ENVIRONMENTAL IMPACT CONSIDERATION l

The proposed change does not involve a significant

-hazards consideration, a significant change in the types of or significant increase in the amounts of any effluents that may be released offsite, or a i significant increase in individual or cumulative occupational radiation exposure. Therefore, the proposed change meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22 (c) (9) .

Therefore, pursuant to 10 CFR 51.22(b), an environmental assessment of the proposed change is not required.

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