ML20217B662

Safety Evaluation Supporting Amends 108 & 86 to Licenses NPF-68 & NPF-81,respectively

ML20217B662
Person / Time
Site:	Vogtle
Issue date:	09/30/1999
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20217B657	List: ML20217B650 ML20217B662
References
NUDOCS 9910130007
Download: ML20217B662 (7)

Text

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4 UNITED STATES s

,g NUCLEAR REGULATORY COMMISSION

't WASHINGTON, D.C. 20555-0001

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 108 TO FACILITY OPERATING LICENSE NPF-68 AND AMENDMENT NO. 86 TO FACILITY OPERATING LICENSE NPF-81 SOUTHERN NUCLEAR OPERATING COMPANY. INC.. ET AL.

VOGTLE ELECTRIC GENERATING PLANT. UNITS 1 AND 2 DOCKET NOS. 50-424 AND 50-425 1

1.0 INTRODUCTION

By letter dated April 13,1999, as supplemented by letter dated August 26,1999, Southern Nuclear Operating Company, Inc., et al. (SNC/the licensee) proposed license amendments to change the Technical Specifications (TS) for the Vogtle Electric Generating Plant (VEGP),

Units 1 and 2. The proposed changes would update Limiting Condition for Operation (LCO) 3.0.4 and Surveillance Requirement (SR) 3.0.4 in the existing VEGP TS to be consistent with the versions of the LCO 3.0.4 and SR 3.0.4 as they appear in Revision 1 to NUREG-1431.

The existing VEGP version of LCO 3.0.4, which was based on Revision 0 to NUREG-1431, has a potential cor.flict with its Bases. The existing Bases of LCO 3.0.4 state that "the provisions of LCO 3.0.4 sha.1 not prevent changes in MODES or other specified conditions in the Applicability that result from a normal shutdown." However, this languages does not appear in the existing TS LCO 3.0.4.

The proposed changes to the existing VEGP TS LCO 3.0.4 will eliminate the conflict with its Bases and as stated above will be consistent with Revision 1 to NUREG-1431. SNC requests approval of the proposed changes to support their use during the Fall 1999 refueling outage.

The supplementalletter dated August 26,1999, provided clarifying information that did not change the scope of the April 13,1999, application and the initial proposed no significant hazards consideration determination. The supplementalletter specifically proposed revisions to Notes to modify Condition C of LCO 3.3.1 and Condition A of LCO 3,3.8. The supplemental letter further committed to revise cold overpressure protection system enable temperature as part of the next update to the pressure and temperature limits for VEGP. Finally, the supplemental letter proposed revising TS to allow entry into the Applicability of LCO 3.4.12 (entry into Mode 4 from Mode 3) with one required power operated relief valve inoperable provided the licensee adheres to certain restrictions outlined in the TS.

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- 2.0 EVALUATlQN.

-The existing VEGP TS LCO 3.0.4, based on Revision 0 to NUREG-1431, states, in part, "This specification shall not prevent changes in MODES or other specified conditions in

. the Applicability that are required to comply with ACTIONS."

The proposed change would add the words "or that are part of a shutdown of the unit," to make

it clear that LCO 3.0.4 would not prevent shutdowns that are not necessarily required by TS Required Actions. These added words eliminate the above stated conflict between existing LCO 3.0.4 and its Bases.'. In addition, the' proposed change to LCO 3.0.4 would also add the following:

"LCO 3.0.4 is only applicable for entry into a MODE or other specified condition in the Applicability in MODES 1, 2, 3, and 4."

Similarly, the existing VEGP TS SR 3.0.4 states, in part,

~ "This provision shall not prevent entry into MODES or other specified conditions in the Applicability that are required to comply with ACTIONS."

The proposed change would add the words "or that are part of a shutdown of the unit," to make

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- it clear that SR 3.0.4 would not prevent shutdowns that are not necessarily required by TS 1

required actions. In addition, the proposed change would also add the following:

"LCO 3.0.4 is only applicable for entry into a MODE or other specified condition in the Applicability in MODES 1,2,3, and 4."

The staff's review finds that the proposed changes for LCO 3.0.4 and SR 3.0.4 are consistent

,with Revision 1 to NUREG-1431 and are, therefore, acceptable. The Bases language that corresponds to the proposed changes is also taken from Revision 1 to NUREG-1431. The staff's review finds these revised Bases acceptable.

However, the Mode restrictions of the existing VEGP versions of LCO 3.0.4 and SR 3.0.4 are appWeable in all Modes. The above proposed change has the effect of removing those Mode restrictions from MODES 5 and 6. In other words, the proposed chtsnges provide additional Mode change flexibility that is not allowed by the existing VEGP TS. As a result, Revision 1 to i

NUREG-1431 version of LCO 3.0.4 and SR 3.0.4 includes a reviewer's note that requires an evaluation of the entire existing TS to determine where specific restrictions on Mode changes or Required Actions should be included in individual LCO to justify the change.

The licensee has performed this evaluation, which is summarized in a matrix that is included in of the submittal dated April 13,1999. Based on the licensee's evaluation, in some cases this additional flexibility has been determined to be inappropriate. In those cases, Notes

- restricting this flexibility have been proposed for specific affected LCOs. These affected LCOs are as follows:

LCO 3.1.1; LCO 3.3.1, Condition C; LCO 3.3.8, Condition A; LCO 3.4.8; LCO 3.4.12; LCO 3.9.1; and LC,0 3.9.6.

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. t*- The NRC technical staff has reviewed the proposed restrictive Notes for the above identified LCOs and their Bases. The staff's review results are as follows:

((1) LCO 3'1.1 Shutdown Margin - The licensee proposes to add a note in LCO 3.1.1 which

_. states:

'While this LCO is not met, transition to a lower Mode within the i

__ Applicability, and entry into Mode 5 from Mode 6 is not permitted."

This note is needed since the required shutdown margin (SDM) is increased at lower modes.

Thus, transitions from a high mode to a lower mode should not be made when the required SDM margin for this lower mode is not yet met. Also, entering Mode 5 without SDM met implies that the more restrictive SDM for Mode 6 has not been met. Under this condition, a transition to

- Mode 5 should not be made until the required SDM for Mode 5 is met. The licensee also proposes a note in the bases section of this LCO to describe the note proposed in LCO. The

- staff finds that the proposed notes are acceptable.

(2) ' LCO 3.3.1 Reactor Trip System (RTS) Instrumentation - The April 13,1999, submittal proposed to add a note to modify Condition C of LCO 3.3.1. The proposed note was as follows:

'With Function 1,17,18, or 19 in Table 3.3.1-1 not met, do not close the reactor trip breakers."

l However, the staff's review determined that the note as expressed above was not consistent with a Note already approved by the NRC staff in the same application for several other plants

~ that were also using the improved Technical Specifications (ITS) as represented by NUREG-1431. _Therefore, in a resubmittal dated August 26,1999, SNC has enclosed marked-up pages from the VEGP TS and Bases reflecting the following Note as applied to j

LCO 3.3.1, Condition C.

"While this LCO is not met for Functions 1.-17,18, or 19 in MODE 5, closing the reactor trip breakers is not permitted."

l The above revised Note only applies in MODE 5. The reason for adding a Note is that' l

Functions 1,17,18, or 19 are required to be operable in MODES 3,4, and 5 with the reactor trip breakers closed and the rod control system capable of rod withdrawal. _ Closing the reactor

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n trip breakers in these modes would constitute entry into the LCO applicability for these

' functions.- However, the proposed change to LCO 3.0.4 would make LCO 3.0.4 only applica' le o

_ in MODES 1 thru 4.' Therefore, a restriction is necessary for MODE 5, since LCO 3.0.4 would l

- no longer apply to MODE 5. It is not necessary to add a restriction for MODES 3 and 4 since

' LCO 3.0.4 would continue to apply in these' modes. The staff finds the revised notes to be acceptable.

(3) E LCO 3.3.8 High Flux at Shutdown Alarm (HFASA) - The April 13,1999, submittal proposed a Note that modified Condition A of LCO 3.3.8 as follows

"With one channel of HFASA inoperable, entry into the Applicability and MODE transition within the Applicability is permitted provided that p. _Y

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,5 o required Action B.1 and B.2 and their associated Completions Times are met within the time of entry into the Applicability or the MODE transition, as applicable."

The staff's review concurred with the intent of the Note, but commented that the Note more properly modified Required Action A.1 rather than Condition A itself. In addition, the staff felt that the Note could be expressed in simpler terms, and requested that the Bases provide a more detailed discussion of the reason for the Note. In the August 26,1999, resubmittal, the pages from LCO 3.3.8 and Bases have been marked-up to apply a Note to Required Action A.1, and the Note has been simplified to read as follows:

" Exception to LCO 3.0.4: MODE changes are only permitted when Required Actions B.1 and B.2 are met."

The basis for adding the Note is as follows. LCO 3.0.4 allows Mode changes when the associated Actions to be entered provide for continued operation for an unlimihd period of time, or to comply with Actions, or to facilitate a shutdown of the unit. The associated Actions of LCO 3.3.8 provide for continued operation for an unlimited period of time. Therefore, with one channel of HFASA inoperable, LCO 3.0.4 would permit entry into the Applicability of 3.3.8 and Mode changes within the 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> Completion Time allowed by Required Action A.1, before Condition B and Required Actions B.1 and B.2 would become applicable. In particular, when transitioning down through MODES 3,4, and 5, the shutdown margin requirements become more restrictive to compensate for a postulated boron dilution event. Required Action B.1 is a periodic verification of shutdown margin, and Required Action B.2 ensures that the unborated water source isolation valves are shut, precluding a boron dilution event. With one channel of HFASA inoperable, it is prudent to take the compensatory actions of Required Actions B.1 and 8.2 if Mode changes are desired or required. The Bases have been marked-up to include the above explanation. The staff's review finds these changes to be acceptable.

(4) LCO 3.4.8 Reactor Coolant System (RCS) Loops - (Mode 5 Loops Not Filled) - The licensee proposes to add a Note which states:

"While this LCO is not met, entry into MODE 5 with RCS loops not filled is not permitted."

This Note is needed since during Mode 5 with loops not filled, the residual heat removal (RHR) system is essential for prcviding decay heat removal capability. Also, without an RHR train in operation, the boron dilution safety analysis will not bound these plant conditions. Therefore, l

when this LCO is not met, it is unsafe to enter MODE 5 with loops not filled. The licensee also proposes a Note in the bases section of this LCO to describe the Note proposed in the LCO.

The staff finds that these proposed Notes are acceptable.

(5) LCO 3.4.12 Cold Overpressure Protection System - In its letter dated April 13,1999, supplemented by a letter dated August 26,1999, the licensee proposes to add the following two Notes:

1)"While this LCO is not met, entry into MODE 6 with the reactor vessel head on from Mode 6, and entry into Mode 5 from Mode 6 with the reactor vessel head on is not permitted."

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e aV l 2)'With one required PORV inoperable for the purpose of cold i

overpressure protection: entry into MODE 4 from MODE 3 is l

permitted provided that RCS temperature is maintained above 275 "F, l~

and, within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />, either the PORV is restored to OPERABLE l

status, or an RHR suction relief valve is placed in service so that the requirements of LCO 3.4.12 are met. Otherwise, the reactor vessel

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must be depressurized and vented in accordance with Required Action F.1."

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' (6) SThe licensee also proposes a revised BASES 3.4.12 which provides the technical bases of

' its proposed Notes.

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In its letter dated August'26,1999, the licensee stated that it will revise the Cold Overpressure Protection System (COPS) enable temperature as part of the next update to

' the pressure and temperature limits for Vogtle units early next year. The licensee intends to use the methodology allowed by ASME Code Case N-514 for determining the COPS l

. enable temperature. Using this methodology, the estimated COPS enable temperature at l-Vogtle units will be well below 275 *F. Since the current COPS enable temperature is conservatively set at 350 *F, as a compensatory measure, the proposed Note 2 also requires action within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> to restore the redundant COPS after entering MODE 4 (as contrasted to the previous LCO 3.4.12 Condition D 7-day provision). This requirement will further minimize the risk associated with a postulated cold overpressure event at the RCS temperature of above 275 *F and inadequate COPS. Therefore, the staff considers that to l

enter MODE 4 above 275 *F from MODE 3 with one inoperable PORV does not present a safety concern. Therefore, the staff finds that the licensee proposed Notes are acceptable.

(7) LCO 3.9.1 Boron Concentration - The licensee proposes to add a note which states:

"With the RCS boron concentration specified in the COLR for Mode 6 L

' not met, entry into Mode 6 is not permitted."

This note is needed to prevent a transition from MODE 5 to MODE 6 without adequate boron concentration to satisfy MODE 6. The note does not need to cover the potential transition from a defueled condition to MODE 6 since the required actions in this TS would prevent this trarden by suspending core alteration and positive reactivity additions. - The licensee also

- proposed a note in the bases section of the LCO to describe the note proposed in LCO. The staff finds that the proposed notes are acceptable.

L (8) LCO 3.9.6 Residual Heat Removal and Coolant Circulation - Low Water Level - The licensee proposes to add a note which states:

While this LCO is not met, entry into Mode 6 with water level less than 23 feet above the top of the reactor vessel flange is not permitted."

' This note is needed to assure adequate decay heat removal capability by RHR systems in the low water level conditions. - Also, when RHR is not operable during MODE 5 or MODE 6 with high water level, immediate action is required to restore RHR to operable status. While this 1

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. required action is not completed, a transition from these Modes should be deferred. The licensee also proposes a note to the bases section of the LCO to describe the note proposed in j

the LCO.; The staff finds that the proposed notes are acceptable.

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3.0 STATE CONSULTATION

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l in accordance with the Commission's regulations, the Georgia State official was notified of the j

proposed issuance of the amendments. The State official had no comments.

4.0 ENVIRO' NMENTAL CONSIDERATION The amendments change requirements with respect to installation or use of a facility I

component located within the restricted area as defined in 10 CFR Part 20 and change surveillance requirements. The NRC staff has determined that the amendments involve no j

significant increase in the amounts and no significant change in the types of any effluents that may be released offsite and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding

. that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (64 FR 43779).- Accord:ngly, the amendments meet the eligibility criteria for categorica! exclusion set forth in 10 CFR S1.22(c)(9). Pursuant to 10 CFR l

- 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.

5.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by

. operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributors: Chu-Yu Liang '

Carl S. Schulten

~ Angela T. Chu

~ Datei September 30, 1999 1

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,!. B. Beasley, Jr. September 30, 1999 A copy of the related Safety Evaluation is also enclosed. A Notice of issuance will be included in the Commission's biweekly Federal Register notice.

Sincerely, ORIGINAL SIGNED BY:

Ramin Assa, Project Manager, Section 1 Project Directorate 11 3

Division of Licensing Project Management i

Office of Nuclear Reactor Regulation l

Docket Nos. 50-424 and 50-425

Enclosures:

1. Amendment No.108 to NPF-68

2. Amendment No. 86 to NPF-81

3. Safety Evaluation cc w/encis: See next page DISTRIBUTION:

RScholl (e-mail SE only)

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Docket Fila.

PSkinner, Ril -

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