L-78-242, 07/20/1978 Letter Supplement to Proposed Amendment to Facility Operating Licenses to Allow Full Power Operation with Up to 25% of the Steam Generator Tubes Plugged

07/20/1978 Letter Supplement to Proposed Amendment to Facility Operating Licenses to Allow Full Power Operation with Up to 25% of the Steam Generator Tubes Plugged

ML18227D802
Person / Time
Site:	Turkey Point
Issue date:	07/20/1978
From:	Robert E. Uhrig Florida Power & Light Co
To:	Stello V Office of Nuclear Reactor Regulation
References
L-78-242
Download: ML18227D802 (5)

Text

REGULATORY INFORMATION DISTRIBUTION YSTEM (RIDS>

DISTRIBUTION FOR INCOMING MATERIAL 50-250 2 1 REC: STELLO V ORG: UHRIG R E DOCDATE." 07/20/78 NRC FL PWR 8. LIGHT DATE RCVD: 07/28/7".

DOCTYPE: LETTER NOTARIZED: NO COP I E RECEIVED

SUBJECT:

LTR 3 ENCL 40 FORWARDING SUPPLEMENT TO APPLICANT"S 07/10/78 PROPOSED AMEND TO LIC NOS DPR-31 4 41 RE FULL PWR OPERATION WITH UP TO 25/. OF STEAM GENERATOR TUEWES PLUGGED'ONSISTING OF NON LOCA ACCIDENTS SAFETY EVALUATION FOR HIGHER LEVELS OF STEAM GENERATOR TUBE PLUGS /<4 PLANT NAME: TURKEY PT 03 REVIEWER INITIAL: X JM TURKEY PT 04 DISTRIBUTER INITIAL: ~

DISTRIBUTION QF THIS MATERIAL IS AS FOLLOWS GENERAL DISTRIBUTION FOR AFTER ISSUANCE OF OPERATING LICENSE.

(DISTRIBUTION CODE A001)

FOR ACTION: BR CHIEF ORB01 BC4+W/7 ENCL INTERNAL: R G F L~M W/ENCL NRC PDR+4W/ENCL E~~W/2 ENCL OELD++'LTR ONLY HANAUER++W/ENCL CORE PERFORMANCE BR>+W/ENCL AD FOR SYS 8( PROJ+4W/ENCL ENGINEERING BR++A/ENCL REACTOR SAFETY BR44W/ENCL PLANT SYSTEMS BR+>W/ENCL EEB~~W/ENCL 'EFFLUENT TREAT SYS+4W/ENCL J. MCGOUGH+4W/ENCL EXTERNAL: LPDR S MIAMIi FL++W/ENCL TERA++W/ENCL NSIC4+WfENCL ACRS CAT B>+W/16 ENCL DISTRIBUTION: LTR 40 ENCL 39 CONTROL NBR: 7820~0005 S I ZE: 3P+43P THE END %4 4 +%4%%4 %%%44 %0%%%%%4 %4%%%%%%4%4 4

r"LQF!1D* pGSVHR ~o s lo'iti COiVipAAY July 20, l978 L-78-242 Office of Nuclear Reactor Regulation Attention: Hr. Victor Stello, Director Division of Operating Reactors U. S. Nuclear Regulatory Coranission Washington, D. C. 20555

Dear Nr. Stello:

Re: Turkey Point Units 3 and 4 Docket Nos. 50-250 and 50-251 Supplement to Proposed Amendment to Facility 0 eratin Licenses DPR-31 and DPR-41 Florida Power & Light Company (FPL) letter L-78-230 of July 10, 1978, con-tained proposed amendments to the Turkey Point Units 3 and 4 Operating Licenses to allow full power operation with up to 25K of the steam generator tubes plugged. The proposed amendments resulted from an evaluation of non-LOCA transients. An analysis of the LOCA transients, which could lead to further proposed amendments, is scheduled to be submitted by August 10, 1978.

On July 12, after receipt of the FPL July 10 submittal, the NRC staff initiated a telephone conference call to discuss the FPL safety evaluation submitted in support of the proposed amendments. During the phone call, FPL representatives and the NRC staff scheduled a meeting for the purpose of continuing the discussi on. The meeting was held on July 13, 1978. As a result of the meeting, it was agreed that FPL would submit a supplement to the July 10 lette~ containing a corresponding evaluation developed by the NSSS vendor . The NSSS vendor analysis is attached. The difference between it and the FPI analysis is as follows:

a) Section 3.2 - Evaluation The NSSS vendor did not consider the effects of fuel rod bow in the evaluation and recommended that the generic rod bow penalty on F~H be applied. Where appropriate, FPL modified the evalua-tion such that it included the effects of a rod bow penalty, consistent with a previous submittal (FPL letter L-77-106 of April 4, 1977) and showed that the rod bow penalty could be ab-sorbed ~iithout a reduction in F~H. Any other differences are edi tori al in nature.

b) Section 3.3.1 -, Uncontrolled Control Rod Assembl Mithdrawal at Power

/

The NSSS vendor reanalysis did not include the development of new transient curves. Instead the NSSS vendor examined the setpoints and concluded that there was substantial margin in the current toe~

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Office o f Nuclear Reactor Regulation Page Three Please call if you have further questions regarding this or previous submittals ~

Very truly yours, Robert E. Uhrig Vice President REU/MAS/RDH/cpc Attachment cc: Mr. James P. O'Reilly, Region EI Robert Lowenstein, Esquire

Office of Nuclear Reactor Regulation Page Two (FSAR) Overtemperature dT setpoint and that the Overpower aT setpoint should be changed. FPL performed a reanalysis of the transients with the setpoints developed by the NSSS vendor with the rod bow penalty included and showed that the DNBR limits were not violated. The Overpower aT and Overtemperature aT setpoints resulting from the two reanalyses are therefore identical.

c) Section 3.3.2 - Loss of'eactor Coolant Flow Flow Coast-Down ccident The NSSS vendor reanalysis did not consider the effects of fuel rod bow. FPL modified the reanalysis to include a rod bow penalty.

Although the vendor reanalysis did not consider rod bow, the minimum DNBR obtained by the vendor during the transient is 1.48. This value shows that the effect of rod bowing can be accommodated wi thout penalizing any operating parameter.

d) Section 4.0 Technical S ecifications The only difference between the Technical Specifications proposed by the NSSS vendor and FPL are the Reactor Core Thermal and Hydraulic Safety Limits curves, Figure F 1-lb. In generating these curves the vendor did not include the effects of rod bow penalty, but FPL did. The FPL curves were developed using the COBRA code exclusively, in conformance wi th the methods used to generate the companion curves, submitted in FPL letter L-78-217 on June 22, 1978, for lesser amounts of steam generator tube plugging. As the rod bow penalty is already included in these curves, there is no need for any further penalty to the F<H limit or to any other operating parameter.

e) Section 6.0 - References FPL requests a timely review of their Safety and Fuel Management Analysis Methods (Reference 6) and of the DYNODE-P Code (Reference 7),

as these methods and codes are to be used in future analyses to be submitted by FPL in support of licensing actions .

A question was raised at the J'uly 13 meeting concerning the NSSS vendor's use of a modified FLARE code on the Unit 4, Cycle 5 design (refer to Unit 4, Cycle 5 Reload Safety Evaluation, FPL letter L-78-210, dated June 19, 1978).

Me have discussed the use of this code with NSSS vendor representatives, and they have verified that all uses of the FLARE model for the cycle 5 design

,.were backed up (confi rmed) with the use of their standard methods.