ML18227C720

Letter Transmitting Proposed Amendment to Facility Operating Licenses, Proposing Amend to Tech Spec Consisting of Revisions to Tech Spec with Regards to Control Rod & Power Distribution Limits

ML18227C720
Person / Time
Site:	Turkey Point
Issue date:	02/25/1976
From:	Robert E. Uhrig Florida Power & Light Co
To:	Stello V Office of Nuclear Reactor Regulation
References
L-76-69
Download: ML18227C720 (20)

Text

NRC FORM 195 I2 76)

U.S. NUCLEAR REGULATORY C ION

"'N~gi FILE NUMBER NRC DISTRIBUTION FQR PART 50 DOCKET MATERIAL TOI FRoM:Flordia Power & Light Co. DATE OF DOCUMENT V. Stello Miami, Flordia 2-25-76 R.E. Uhrig DATE RE C) I V E 9 C3LETTER $ 5NOTOR I2E 0 PROP INPUT FORM NUMBER OF COPIES RECEIVED 5IOR IGINAL Gl UN C LASS I F I E D 0 COPY DEscRIPTIDN Ltr. notari zed 2-25-76... ENCLOSURE Ltr. trans the following....... Proposed Amdt. to OL/Change to Tech. Specs:

Consisting of revisions to,Tech,- Spec, with regards to Control Rod and Power Distrubution .

Limits.....W/Attachments (1 Signed Cy. Received)

ACKNOW',EDGED.

Turkey Point 0 3 8 4 PLANT NAME. DO NOT REMOVE S FETY FOR ACTION/INFORMATION ENVIRO SAB 3-5-76 SSIGNED AD; ASSIGNED AD .-

BRANCH CHIEF: ear BRANCH CHIEF ~

PROJECT MANAGER; PROJECT MANAGER :

CD ST arras LIC, ASST INTERNAL D IST RI BUTION C PDR ERNST 8c E BENAROYA ALLARD SPANGLER OSSICK 6 STAFF EN INEER N IPPOLITO SITE TECH KNIGHT OPERATING REACTORS GAMMILL SIHWEIL STELLO STEPP

. PAm.ICKI HUIIIAN OPERATING TECH PROJECT MANAGEMENT REACTOR SAFETY SENHUT SITE ANALYSIS BOYD ROSS VOLIMER P, COLLINS NOVAK ER HOUSTON ROSZTOCZY CHWENCER J COLLINS PETERSON CHECK RIMES KREGER MELTZ HELTEMES AT&I SITE SAFETY & ENV R SKOVHOLT SALTZMAN ANALYSIS RUTBERG DENTON 6c MULLER EXTERNAL DISTRIBUTION CONTROL NUMBER LpD ~ Ms am> a. 'NATL LAB BROOKHAVEN NATL LAB TIC REG V-IE ULRIKSON(ORNL)

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~cu p(g FLORIDA POWER 5 LIGHT COMPANY il SP9 February 25, 1976 L-76-69 Office of Nuclear Reactor Regulation ATTN: Mr. Victor Stello, Jr., Director Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D. C. 20555

Dear Mr. Stello:

Re: Turkey Point Units 3 and 4 Docket Nos. 50-250 and 50-251 Proposed Amendment to Facility 0 eratin Licenses DPR-31 and DPR-41 In accordance with 10 CFR 50.30, Florida Power & Light Company submits herewith three (3) signed originals and forty (40) conformed copies of a request to amend Appendix A of Facility Operating License DPR-41.

Unit 4 is currently in its second cycle of operation. A refueling outage is scheduled for April 19, 1976 with Cycle 3 startup planned for late May. This submittal proposes Technical Specification changes relating to the Control rod insertion limits for Unit 4, Cycle 3. The changes are minor and clarify the control rod insertion limit curves and explanatory text. which will be applicable to Cycle 3.

The proposed Technical Specification changes are as des-cribed below and as shown in the accompanying Technical Specification pages bearing the date of this letter in the lower right. hand corner.

Pa e 3. 2-1 Sections 3.2.l.b, 3.2.1.c, and 3.2.l.d are amended to clarify the applicability of control group insertion limit.

curves for Units 3 and 4. Sections 3.2.1.b and 3.2.l.c are reworded to be consistent with one insertion limit applicable for an entire fuel cycle.

~Fi ure 3. 2-1 The control group insertion limit graph for Unit 4 three loop operation is revised to be consistent with one insertion HELPING BUILD FLORIDA

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Mr. Victor Stello February 25, 1976 limit which is applicable for the entire cycle. The revised graph is identical to the dashed-line portion of the Cycle 2 graph.

Fi ure 3.2-1(a)

More conservative control group insertion limits are provided for Unit 4 two loop operation.

The bases for specification 3.2 are amended to be consistent with one insertion limit which is applicable for an entire fuel cycle.

The proposed amendment has been reviewed and the conclusion reached that it does not involve a significant hazards consid-eration because the proposed contxol, group insertion limits are more conservative than current limits. Therefore, prenoticing pursuant to 10 CFR 2.105 should not be required.

Very truly yours, Robert E. Uhrig Vice President REU:MAS:nch Attachments cc: Mr. Norman C. Moseley Jack R. Newman, Esquire

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STATE OF FLORlDA )

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Robert E. Uhrig, being first duly sworn, deposes and says:

That he is a Vice President of Florida Power S Light. Company, the Licensee herein; That he has executed the foregoing document; that the statements made in this said document are true and correct to the best of his knowledge, information and,belief; and that he is authorized to execute the document on behalf of said Licensee.

Robert E. U rz.g Subscribed and sworn to before me t:his g Bay of / 1976 ee',

t Not y Public, in and for the County of e Dad , State of Florida L

PL'"r te NOTARY <<C STATE OF FlORIDA AT lARGE ~i )r JAN. 26, 1979 r(s lrDt o My Commission expires:

MY CO]rIMISSIOH EXPIRES N tC'. I (sh" 1 W fraatrrl C 1 tartr

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3.2 " CONTROL ROD AND POWER DXSTRXBUTXON LXMXTS Applies to the operation of the control rods and power distribution limits.

. ~0b'ective: To ensure,.(l) core subcriticality after a reactor trip,'2) a limit on potential reactivity insertions from a hypo-thetical control rod ejection, and (3) an acceptable core power distribution during power operation.

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Whenever the reactor is critical, except for. physics tests and control rod exercises, the shutdown control rods shall be fully withdrawn.

b. For Unit 4, whenever the reactor is critical, except for physics tests and control rod exercises, the control 'group rods shall be no further inserted than the limits shown on Figure 3.2-1 for three loop operation and on Figure 3.2-1(a) for two loop 'I operation.

c. h'or Unit 3, whenever the reactor is critical, ex-cept for physics tests and control rod exercises,

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the control group rods shall be no- further in-serted than the limits shown on Figure 3.2-1(b)'or three loop opeiation and on Figure 3.2-1(c) for two loop operation.

The Unit 4 contcol rod insertion limits shown on Figure 3.2-1 and the Unit 3 control rod insertion limits shown on Figure 3.2-1(b)"may be revised on the basis of physics calculations and physics data obtained during startup and subsequent operation.

e. Part length rods shall not be permitted in the core except for low power physics tests and for axial offset calibration tests performed below 75% of rated power.

2/25/76 3.2-1

0 UNIT 4 CONTROL CROUP INSERTION'LIMITS FOR THREE LOOP OPFRATION 100 80 Bank C

~t 60 40-Bank D 20 0

0 20 40 60 80 l00 POWER LEVEL, PERCENT RATED 4

FIGURE 3.2-1 2/2S/76

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UNIT 4

,CONTROL GROUP INSERTION LIMITS I'OR TWO LOOP OPERATION 100 80 ~

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60 40 Bank 7 D 20

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~J 0 , 20 40 60 80 100 POWER LEVEL, PERCENT RATED FIGURE 3.2-1(a) 2!25/76

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B3. 2 BASES FOR LIMITING CONDITIONS FOR OPERATION, CONTROL AND PONER DISTRIBUTION LIGHTS Reactivity changes accompanying changes in reactor power are compensated by control rod motion. Reactivity changes associated with xenon, samarium, fuel depletion, and large changes in reactor coolant temperature (operating temperature to cold shutdown) are compensated by changes in the soluble boron concentration. During power operation, the, shutdown groups are fully withdrawn and control of reactor power is by the control groups. A reactor trip occurring during power operation will put the reactor into the hot shutdown condition.

The control rod insertion limits provide for achieving hot shutdown by reactor trip at any time, ass'uming the highest worth control rod remains fully withdrawn, with sufficient margins to meet the assumptions used in the accident analysis. (1) In addition, they provide a limit on the max-imum inserted rod worth in the unlikely event of a hypothetical rod ejection, and provide for acceptable nuclear peaking factors. Figures 3.2-1 and 3.2-1(a) meet the shutdown requirements of Unit 4. Figures 3.2-1(b) and 3.2-1(c) meet the shutdown requirements of Unit 3. The Unit 4 and Unit 3 rod insertion limits may be determined on the basis of startup and operating data to provide a more realistic limit which operation and still assure com-m will allow for more flexibility in pliance with the shutdown requirement. The maximum shutdown margin requirement occurs at end-of-core life and is based on the value used 1

in analysis of the hypothetical steam break accident. Early in core life, less shutdown margin is required, and Figure 3 '-2 shows the shutdown margin equivalent to 1.77% reactivity at end-of-core-life with respect to an uncontrolled coold'own. All other accident analyses are based on 1% reactivity shutdown margin.

B3 ~ 2-1 2/25/76

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SAFETY EVALUATION Introduction By letter dated February 25, 1976, Florida Power and Light Company (FPL) proposes changes to the Technical Specifications of Facility Operating Licenses DPR-31 and DPR-41 for Turkey Point Nuclear Generating Units 3 and 4. The proposed changes clarify the control rod insertion limits, a limiting condition for oper-ation (LCO), fo'r Unit 4 Cycle 3.

Because Units 3 and 4 share joint Technical Specifi-cations, FPL proposes to modify the Technical Speci-fications for Unit 3 to refl'ect the proposed revision to the Unit 4 Technical, Specifications. However, the operating limits for Unit 3 are unchanged by the Unit 4 reload for core Cycle 3.

Discussion Section 3.2 of the Technical Specifications contains graphs which define the control group insertion limits for two-loop and three-loop operation. A description of what the insertion limits provide is contained in Section 'B3.2. Current Sections 3.2.1 and B3.2 have provisions for adjusting the Unit 4 insertion limits after 70% burnup of Cycle 2. Cycle 3, however, will have one insertion limit which is applicable for the entire cycle. Therefore, appropriate revisions have been made t'o the text and figures applicable to the Unit 4 insertion limits. The revisions are minor and are intended to clarify the text and graphs associated with Unit 4 to avoid confusion between Cycle 2 and Cycle 3 insertion limits.

The three loop insertion limit for all of Cycle 3 .is the same as the corresponding limit for the end of Cycle 2. The two-loop insertion limit for Cycle 3 is more conservative than the corresponding limit for Cycle 2.

Conclusions The proposed amendment will not result in any physical change to plant equipment or systems and will not ef-fect previously performed applicable safety analyses.

Comparison of Cycle 2 and Cycle 3 insertion limits shows that the proposed limits are at least as conser-vative as current limits and will provide an adequate shutdown margin throughout Cycle 3 life. The proposed amendment is consistent with the plant operation, neces-sary for the design and safety evaluation conclusions contained in the Unit 4 Cycle 3 Reload Submittal to

0 Based on these considerations, (l) the proposed change does not increase the probability or consequences of accidents or malfunctions of equipment important to safety and does not reduce the margin of safety as de-fined in the basis for any technical specification, therefore, the change does not involve a significant hazards consideration, (2) there is reasonable assur-ance that the health and safety of th'e public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not, be inimical to the common de-fense and security or to the health and safety of the public.

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