ML20106E436

Proposed Rev to 840905 Tech Spec Changes Re Support Analog Transmitter Trip Sys Installation

ML20106E436
Person / Time
Site:	Hatch
Issue date:	10/18/1984
From:	GEORGIA POWER CO.
To:
References
TAC-55695, NUDOCS 8410290231
Download: ML20106E436 (9)

Text

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ENCIOSURE NRC DOCKET 50-321 OPERATING LICENSE DPR-57 EDWIN I. HA701 NUCLEAR PIANT UNIT 1 REVISION OF REQUEST FOR TECINICAL SPECIFICATION CHANGES TO SUPPORT ANAIDG TRANENI7TER TRIP SYSTEM INSTALLATION The following changes should be made to the docment entitled "Edwin I.

Hatch Nudlear Plant Unit 1, Docket No. 50-321, Technical Specifications Revisions Associated With Installation of Analog Transnitter Trip Systen" which 'was enclosed with Georgia Power Company Letter NED-84-436 (dated September 5,1984), using the pages enclosed with this subnittal:

Renove Page Insert Page 4-26 4-26 4-28a 6-2 6-2 6-3 6-3 3.2-6*

3.2-28*

i 3.2-54*

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• These pages are new proposed Unit 1 Technical Specification pages and should be added to_the section entitled " Proposed Technical Specifications Revision".

• • 1his page contains the significant hazards evaluation required for this revision by 10 CER 50.92 and should be added to Appendix 1.

8410290231 841018 DRADOCK05000g

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4.B.12 Miscellaneous Trio Setooint/ Allowable Value Modifications 4.B.12.a. New calculations were performed to determine the new'setpoint value for each ATTS instrument. The setpoint calculations were made using the criteria of Regulatory Guide 1.105. The Plant Hatch analytical limits were used (where applicable) to develop the allowable values and trip setpoints. Unless identified in the text, the analytical

limits used to develop these setpoints are the values used in the design basis of Plant Hatch. The values that are proposed to be inserted into.the Technical Specifications are the calculated allow-able values. The setpoints used at Plant Hatch will take into consideration instrument drift and will be developed frcm the allow-able values. The proposed Technical Specifications revisions include modifications of the trip setpoints/ allowable values for the follow-ing instruments:

RPS Trio Function Trip Unit MPL No.

1. Reactor vessel steam dome B21'N678A,B,C,D pressure - high

2. Reactor vessel water level - B21-N6SOA,B,C,0

. Level 3

3. Reactor vessel water level - 821-N681A,B,C,D Level 1 ECCS Trio Function Trip Unit MPL No.

1. Reactor vessel water level - B21-N691A,B,C,D Level 1

2. Reactor vessel steam dome 221-N690A,B,C,0 pressure - low

3. Reactor vessel steam dome B21-N690E,F presssure - low B21-N641B,C

4. Reactor vessel water B21-N695A,B level - Level 3

5. HPCI steamline differential E41-N657A, B pressure - high

. 4-26 Revision 1

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5. HPCI steam line differential pressure - high (E41-N657A,B) i The purpose of this instrumentation is to detect HPCI steam line breaks and to isolate the HPCI system to confine the resulting radioactivity release and limit the reactor inventory loss. The HELB analysis assumes that the HPCI turbine trips and the system isolates at 300 percent of rated flow. However, the HELB analysis is used for guillotine breaks which have flows several times higher than 300 percent of rated flow. A conservative analysis shows the leakage detection instrumentation isolates in the 400 percent of rated flow range with less inventory loss and less peak qualification parameters than the inventory loss and the qualification parameters calculated in the extreme HELB analysis. Since operability problems are a concern with setpoints derived from an analytical limit of 300 percent using Regulatory Guide 1.105 methodology for this function, it is proposed that the present Plant Hatch setpoint be maintained. This setpoint has been proven to be acceptable from operability considerations. Using this setpoint, an allowable value of 303 percent of rated flow was selected, taking into account instrument drift.

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4-28a Revision 1 I

TABLE 6.1 INSTRUCTIONS FOR INCORPORATING TECHNICAL SPECIFICATIONS REVISIONS If the Technical Specifications revisions are accepted as proposed, the HNP-1 Technical Specifications (Appendix A to Operating License DPR-57) should be incorporated as follows:

Deletions Insertions Applicable SER*<a>

Item (Page) (Page) Section(s) 1 1.0-6 1.0-6 4.B.10 2 1.1-3 1.1-3 4.B.11, 4.B.12 3 1.1-4 1.1-4 4.B.10 4 1.1-5 1.1-5 4.B.3, 4.B.11, 4.B.12 5 1.1-13 1.1-13 4.B.11, 4.B.12 6 1.1-14 1.1-14 4.B.10 7 Fig. 2.1-1 Fig. 2.1-1 4.B.2, 4.B.3, 4.B.4, 4.B.11, 4.B.12 8 1.2-1 1.2-1 4.B.12 9 1.2-2 1.2-2 4.B.9 10 1.2-4 1.2-4 4.B.9 11 1.2-6 1.2-6, 6a 4.B.9 12 3.1-3 3.1-3 4.B.11, 4.B.12 13 3.1-4 3.1-4 4.B.11, 4.8.12

.14 3.1-5 3.1-5 4.B.10 .

15 3.1-7 3.1-7 ATTS, 4.B.11 16 3.1-8 3.1-8 ATTS 17 3.1-11 3.1 11 4.B.11 3.1-12 3.1-12 4.B.11, 4.8.12 18 19 3.1-14 3.1-14 ATTS 20 3.1-15 3.1-15 ATTS 21 3.1-17 3.1-17 ATTS 22 3.1-18 3.1-18 ATTS 23 3.2-1 3.2-1 4.8.1 24 3.2-2 3.2-2 4.B.2, 4.B.3, 4.B.6, 4.3.11, 4.B.12 25 3.2-5 3. 2- 5 4.B . 3, 4.B .4, 4.B .11, 4. B.12 26 3.2-6 3.2-6 4.B.12 l' 27 3.2-8 3.2-8 4.B. 3, 4.B . 4, 4. B . 5, 4.B .11, 4.B .12 28 3.2-10 3.2-10 4.B.ll , 4.B.12 29 3.2-11 3.2-11 4.B .ll , 4.B.12 30 3.2-14 3.2-14 4.B.11, 4.B.12 31 3.2-20 3.2-20 4.B.3 32 3.2-22 3.2-22 4.B.8 33 3.2-23c 4.B.1 34 3.2-24 3.2-24 ATTS, 4.B.11 35 3.2-27 3.2-27 ATTS, 4.B.11 36 3.2-28 3.2-28 ATTS 3.2-30 3.2-30 ATTS, 4.B.11 l 37 38 3.2-33 3.2-33 ATTS, 4.B.ll 39 3.2-35 3.2-35 ATTS, 4.B.11 40 3.2-38 3.2-38 ATIS, 4.B.ll 6-2 Revision 1

Insertions Deletions Applicable _SER"ca>

Item -(Page) (Page) Section(s) 41' 3.2-45 3.2-45 4.B.11 42 3.2-49c 4.B.1 43 3.2-50 3.2-50,-50a 4.B.2, 4.B.3, 4.B.6, 4.B.9, 4.3.11, 4.B.12 44 3.2-52 3.2-52 Editorial, 4.B.3, 4.B.11, 4.B.12 45 .3.2-53 3.2-53 ATTS t 4.B.4, 4.B.11, 4.B.12 46 3.2-54 3.2-54 4.B .12 l 47 3.2-55 3.2-55 Editoria l , ATTS , 4.B.3, 4.B.11 48 3.2-56 3.2-56 ATTS, 4.B.4, 4.B.5, 4.B.11, 49 3.2-58 3.2-58 4.B.11, 4.B.12 50 3.2-59 3.2-59 4.B.12 51 -3.2-60 3.2-60 4.B.12 52 3.2-62 3.2-62 4.B.11, 4.B.12 53 3.2-68a 3.2-68a 4.B.1 54 3.2-69 3.2-69 ATTS 55 3.6-9 3.6-9 4.B.1 56 3.6-9a 3.6-9a, 9b 4.B.1 57 3.6-21 3.6-21 4.B.1 58 3.6-22 3.6-22 4.B.1 59 3.7-17 3.7-17 4.B.7 60 3.7-18 3.7-1? 4.B.7

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61 3.7-19 3.7-19 4.B.7, 4.B.11, 4.B.6, 4.B.2 62 3.7-35 3.7-35 4.B.2, 4.B.6, 4.B.7, 4.B.11 SER-Safety Evaluation Report a.- 1. ATTS refers to proposed revisions justified in Section III of this submittal.

2. 48.1 through 48.12 refer *.o justifications presented in Section IV of this submittal.

3. Editorial refers to the correction of a typographical error.

Revision 1

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Table 3.2-2 (Cont.)

Recpired Operable Ref. Trip Channels No. Condition . per Trip (a) Instmment - . Nomenclature System (b) Trip Setting Remark

9. HPCI Steam Line Pressure Iow 2 2 100 psig Closes isolation valves.in HPCI system, trips 'HPCI turbine.

10. HPCI Steam Line AP (Flow) High 1 5 303% rated Close isolation valtes in HPCI flow system, trips HPCI turbine,

11. HPCI 'nirbine Exhaust High 1 $ 10 psig Close isolation valtes in HPCI' Diaphragm Pressure system, trips HPCI turbine.

g 12. Suppression Chamber Area High 1 11790F Close isolation valtes in HPCI-m Jabient Tenperature system, trips HPCI turbine.

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13. Suppression Chamber Area High 1 5500F ,

Close isolation valves An hPCI Differential Air Tenperature -

system, trips HPCI turbine.

14. Condensate Storage Tank Inw 2 10 inches hitomatic interlock switches Invel suction from CSP to suppression chamber

15. Suppression Chamber inter High 2 s 0 inches Altomatic interlock switches Letel alction from CIS to alppression chamber

16. HPCI Ingic Power Failure 1 Not Applicable Monitors availability of power Monitor to logic system.

a. 'Ite colunn entitled "Ref. No." is only for convenience so that a one-to-one relationship can be established between items in Table 3.2-2 and items in Table 4.2-2.

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iTable 4.2-2 (Cont'd)

Ref. Instnament Oeck - Instmment RInctional Test - ' Instmment Calibration 1 No. Miniinlm FreqJency Minim 1m Freq2ency. Minin1m Freq2ency (a) (b) - (c)-

10 -HPCI Steam Line Once/ Shift Once/ month. 'Once/ operating cycle l AP (Flow) -

11 HPCI 'R1rbine Exhalst None (d) D ery 3 months Diaphragm Presaire 12 alppression Gamber Area None (d) Every 3 months Ambient Tenperature 13 alppression Gamber Area -None (d) Dery 3 months Differential Air Tenperature

, 14 Cordensate Storage None (d) Dery 3 months

, Tank Iesel i

5 15 alppression Gamber None (d) Dery 3 months eter Iasel 16 HPCI Iogic Power .None Once/ operating cycle None Failure Monitor Notes for Table 4.2-2

a. 'Ibe colunn entitled "Ref. No." 'is only for convenience so that a one-to-one relationship can be established between items in table 4.2-2 and items in Table 3.2-2.

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. i BASES FOR LIMITING CONDITIONS FOR OPERATION 3.2.B.8 HPCI Riuipnent Rom Teperature High (Continued) tmperature setting 900F + abient was selected to be far enough above anticipated normal HPCI systs operational levels to avoid spurious isolation but low enough to provide timely detection of HPCI turbine stem line break. h e high tmperature trip initiates a timer which isolates the HPCI turbine stem line if the ta perature is not reduced below the setpoint.

9. HPCI Stem Line Pressure Iow Iow pressure in the HPCI stem line could indicate a break in the HPCI stem line. %erefore, the HPCI stem line isolation valves are autmatically closed. ne stem line low pressure function is provided so in the event that a gross rupture of the HPCI stem line occurred upstrem fra the high flow sensing location, thus negating the high flow indicating function, isolation would be effected on low pressure. %e allowable value of &100 psig is selected at a pressure sufficiently high so as to prevent turbine stall.

10. HPCI Stem Line AP (Flow) High HPCI stem line high flow could indicate a break in the HPCI l turbine stem line. %e automatic closure of the HPCI stem line isolation valves prevents the excessive loss of reactor coolant and the release of significant mount of radioactive materials fra the nuclear system process barrier. . Upon detection of HPCI stem linc high flow the HPCI turbine stem line is isolated. %e high stem flow trip setting of 303% flow was selected high enough to avoid l spurious isolation, i.e., above the high stem flow rate encountered during turbine starts. %e setting was selected low enough to provide timely detection of an HPCI turbine stem line break.

11. HPCI Turbine Exhaust Diaphragn Pressure High High pressure in the HPCI turbine exhaust could indicate that the turbine rotor is not turning, thus allowing reactor pressure to act on the turbine exhaust line. 'Ihe HPCI stem line isolation valves are autmatically closed to prevent overpressurization of the turbine exhaust line. 'Ihe turbine exhaust diaphragm pressure trip setting of 510 psig is selected high enough to avoid isolation of the HICI if the turbine is operating, yet low enough to effect isolation before the turbine exhaust line is unduly pressurized.

12. Suppression Chaber Area Air Teperature High As in the HPCI quipment room, and for the see reason, a taperature of 900F+ ambient will initiate a timer to isolate the HPCI turbine stem line.

3.2-54

10 CFR 50.92 Evaluation for the Proposed HPCI Steamline Differential Trip

~Setpoint/ Allowable Edwin I. Hatch Value Nuclear Modificati9n)to Plant-Unit lla the Technical Specifications for Georgia Power Company (GPC) reviewed the requirements of 10 CFR 50.92 as they relate to the proposed HPCI steamline differential pressure trip setpoint/

allowable value modification to the Technical Specifications. The purpose of this change is to update the Technical Specifications trip setpoint for these instruments which are being replaced by the analog transmitter trip system (ATTS). Since the time that original setpoint was determined, a better calculational method has been developed. This proposed change uses the Regulatory Guide 1.105 methodology in updating the setpoint for the new ATTS instruments, and takes credit for the improved error and drift characteristics of the new system. This change replaces the trip setpoint listed in the Technical Specifications with the newly evaluated allowable value determined through Regulatory Guide 1.105 methodology.

GPC reviewed the proposed change and considers it not to involve a significant hazards consideration for the following reasons:

1. It will not significantly increase the probability or consequences of an accident previously evaluated, because the new ATTS instruments are of a superior design as compared to the current instruments. In addition, the setpoint was determined using the criteria of Regulatory Guide 1.105, and therefore, still meets the Final Safety Analysis Report (FSAR) criteria.

2. It will not create the possibility of a new or different kind of accident from any accident previously evaluated, because the basic trip function, as described in the FSAR, is unchanged.

3. It will not involve a significant reduction in a margin of safety, because the original design basis was maintained. In addition, Regulatory Guide 1.105 criteria were used in the calculation of the new setpoint, e

a. See subsection 4B.12.b.5 (page 4-28a) for discussion of proposed revisions.

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