ML052660267

Additional Proposed Changes for Technical Specification to Revise Frequency for Tadot of P-4 Interlock

ML052660267
Person / Time
Site:	North Anna
Issue date:	09/23/2005
From:	Matthews W Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
05-330A
Download: ML052660267 (16)

Text

VIRGINIA ELECTRIC AND POWER COMPANY

RICHMOND, VIRGINIA 23261 September 23, 2005 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Serial No.

05-330A NL&OS/ETS R1 Docket Nos. 50-338/339 License Nos. NPF4/7 VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 ADDITIONAL PROPOSED CHANGES FOR PROPOSED TECHNICAL SPECIFICATION CHANGES REVISED FREQUENCY FOR TADOT OF P-4 INTERLOCK In a letter dated March 1, 2005 (Serial No.05-111), Virginia Electric and Power Company (Dominion) requested amendments, in the form of changes to the Technical Specifications to Facility Operating License Numbers NPF-4 and NPF-7 for North Anna Power Station Units 1 and 2, respectively. The proposed changes were requested to revise the frequency for the Trip Actuating Device Operational Test (TADOT) and change the modes of applicability for the P-4 Interlock Function consistent with TSTF 444, Rev. 1. In a August 30, 2005 telephone conference call with the NRC staff to discuss the proposed changes, the NRC questioned: 1) the adequacy of our proposed required actions for an inoperable train of the P-4, and 2) whether existing Technical Specification requirements were sufficient if P-4 was applicable in Mode 4.

Since the call, Dominion has further evaluated the operability requirements of the P-4 interlock to address the NRC concerns. If the P-4 interlock function was required in Mode 4, then the required action would be to take the plant to Mode 5. However, based on our review of the generic analyses performed to support the Westinghouse Shutdown LOCA procedure (ARG-2), we have determined that the P-4 interlock function is not required to be operable in Mode 4 for North Anna to support the manual safety injection function. The operator can take appropriate actions, independent of the operability of P-4, to reduce and/or terminate safety injection as required. Therefore, Dominion is revising the initial proposed Technical Specifications changes, noted above, to eliminate the Mode 4 applicability for the P-4 interlock function.

The revised marked-up page and proposed typed page (TS 3.3.2-11) are included in the attachment to this letter. Please replace the pages from the original March 1, 2005 submittal with the attached pages to complete your review of the proposed amendment.

Serial No. 05-330A Docket Nos. 50-338/339 Page 2 of 4 We have evaluated the original proposed Technical Specification changes with respect to the additional change provided herein and have determined that the proposed changes remain bounded by the No Significant Hazards Consideration Determination and the Environmental Assessment previously provided in our March 1, 2005 submittal.

If you have any further questions or require additional information, please contact Mr. Thomas Shaub at (804) 273-2763.

Very truly yours, k R + 2 = e William R. Matthews Senior Vice President - Nuclear Operations Attachment Commitments made in this letter: None

cc:

U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW Suite 23T85 Atlanta, Georgia 30303 Mr. J. E. Reasor, Jr.

Old Dominion Electric Cooperative lnnsbrook Corporate Center 4201 Dominion Blvd. Suite 300 Glen Allen, Virginia 23060 Commissioner Bureau of Radiological Health 1500 East Main Street Suite 240 Richmond, Virginia 2321 8 Mr. J. T. Reece NRC Senior Resident Inspector North Anna Power Station Mr. S. R. Monarque NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North 1 1555 Rockville Pike Rockville, Maryland 20852 Mr. R. E. Martin NRC Lead Project Manager - North Anna and Surry U. S. Nuclear Regulatory Commission One White Flint North 1 1555 Rockville Pike Rockville, Maryland 20852 Serial No. 05-330A Docket Nos. 50-338/339 Page 3 of 4

Serial No. 05-330A Docket Nos. 50-338/339 Page 4 of 4 COMMONWEALTH OF VIRGINIA

)

COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by William R. Matthews, who is Senior Vice President - Nuclear Operations of Virginia Electric and Power Company.

He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that Company, and that the statements in the document are true to the best of his knowledge and belief.

Acknowledged before me this A3cdday of My Commission Expires:

?!

.G?Ofl/y

,2005.

J

/y&

Notary Public (SEAL)

Serial No. 05-330A Virginia Electric and Power Company North Anna Power Station Units 1 and 2 Proposed Technical Specifications Changes For P-4 Interlock Function Response to Request for Additional Information Revised Marked-up and Proposed TS pages North Anna Power Station Units 1 and 2 Virginia Electric and Power Company (Dominion)

ESFAS Instrumentation 3.3.2 Table 3.3.2-1 (page 4 o f 4)

Engineered Safety Feature Actuation System Instrumentation FUNCTION APPLICABLE MODES OR OTHER SPEC1 FI ED REQUIRED SURVEILLANCE ALLOWABLE CONDITIONS CHANNELS CONDITIONS REQUIREMENTS VALUE

6. Auxiliary Feedwater

a. Automatic Actuation Logic 1, 2, 3 2 t r a i n s G

SR 3.3.2.2 NA and Actuation Relays SR 3.3.2.3 SR 3.3.2.5

b. SG Water Level-Low Low

c. Safety I n j e c t i o n

d. Loss o f O f f s i t e Power

e. T r i p o f a l l Main Feedwater Pumps

7. Automatic Switchover t o Containment Sump

a. Automatic Actuation Logic and Actuation Relays

b. Refueling Water Storage Tank (RWST) Level-Low Low 1, 2. 3 3 Der SG D

SR 3.3.2.1 2 17%

SR 3.3.2.4 SR 3.3.2.8 SR 3.3.2.9 Refer t o Function 1 (Safety Injection) f o r a l l i n i t i a t i o n functions and requi rements.

1, 2. 3 1 per bus, F

SR 3.3.2.6 2 2184 V 2 buses SR 3.3.2.8 SR 3.3.2.9 1, 2 2 per pump H

SR 3.3.2.7 NA SR 3.3.2.9

1. 2, 3. 4 2 t r a i n s C

SR 3.3.2.2 NA SR 3.3.2.3 SR 3.3.2.5 1, 2, 3. 4 4

I SR 3.3.2.1 2 18.4% and SR 3.3.2.4 I 2 0. 4 %

SR 3.3.2.8 SR 3.3.2.9 Coincident with Safety I n j e c t i o n requirements.

Refer t o Function 1 (Safety Injection) f o r a l l i n i t i a t i o n functions and

8. ESFAS Interlocks

a. Reactor Trip, P-4 1, 2, 3 1 per train, 2 t r a i n s F

SR 3.3.2. @

NA

b. Pressurizer Pressure, P-11 1, 2. 3 3

J SR 3.3.2.1 I 2 0 1 0 psig SR 3.3.2.8 C. TaVg-Low LOW, P-12 1, 2. 3 1 per loop J

SR 3.3.2.1 2 542°F and SR 3.3.2.8 C 545°F North Anna Units 1 and 2 3.3.2-11 Amendments 2 - e

ESFAS Instrumentation B 3. 3. 2 BASES APPLICABLE SAFETY

8. Engineered Safety Feature Actuation System Interlocks (continuedl ANALYSES, LCO, AND interlock Functions back up manual actions t o ensure APPLICABILITY bypassable functions are i n operation under the conditions assumed i n the safety analyses.

a. Engineered Safety Feature Actuation System Interlocks-Reactor Trip, P-4 The P-4 interlock is enabled when a reactor trip breaker (RTB) and i t s associated bypass breaker are open. Once the P-4 interlock i s enabled, automatic SI reinitiation i s blocked after a 60 second time delay.

This Function allows operators t o take manual control of SI systems after the initial phase of injection is complete. Once SI i s blocked, automatic actuation of S I cannot occur u n t i l the RTBs have been manually closed, resetting the P-4 interlock. The functions of the P-4 interlock are:

Trip thp main turbinep

>5aZT-1 1

• protect i on system.

North Anna Units 1 and 2 B 3.3.2-29

~~

Revision B-

ESFAS Instrumentation B 3.3.2 BASES APPLICABLE

8.

SAFETY ANALYSES, LCO,

AND APPLICABILITY Engineered Safety Feature Actuation System Interlocks (continued)

a. Engineered Safety Feature Actuation System Interlocks-Reactor Trip, P-4 (continued) excYed

/

/

operation.

Interlocks-Pressuri zer Pressure, P-11 The P-11 interlock permits a normal unit cooldown and depressurization without actuation of SI. With two-out-of-three pressurizer pressure channels (discussed previously) less than the P-11 setpoint, the operator can manually block the Pressurizer Pressure-Low Low SI signal. Additionally, the P-11 signal blocks the automatic opening of the pressurizer power operated re1 ief valves (PORVs).

With two-out-of-three pressurizer pressure channel s above the P-11 setpoint, the Pressurizer Pressure-Low Low SI signal is automatically enabled. The operator can also enable this function by use of the respective manual reset switches. The automatic opening capability for the pressurizer PORVs is

b. En ineered Safet Feature Actuation S stem I

(continued)

North Anna Units 1 and 2 B 3.3.2-30 Kevi si on -&

Insert 1 Function Isolate MFW Regulating Valves with coincident low Tavg Trip the main turbine Prevent automatic reactuation of SI after a manual reset of SI Reset high steam flow setpoint to no-load value (1) SI-High Steam flow in Two Steam Lines Coincident With Steam Line Pressure - Low (2) SI - High Steam Flow in Two Steam Lines Coincident With Tavg - Low Low Steam Flow in Two Steam Lines Coincident With Steam Line Pressure - Low (4) Steam Line Isolation - High Steam Flow in Two Steam Lines Coincident With Tavg

- Low Low Prevent opening of the MFW Regulating Valves if they were closed on SI or SG Water Level - High High (3) Steam Line isolation - High Purpose Feedwater isolation Prevents excessive cooldown, there by Condition II event does not propagate to Condition Ill event Allows alignment of ECCS for recirculation mode, prevents subsequent inadvertent alignment to iniection mode bv auto SI Ensures setpoint is reset to low/zero power reference value following plant trip, regardless of turbine first stage pressure indication Seal-in feedwater isolation to prevent inadvertent feeding of de-pressurized SG Required MODES 1,2 1, 2,3 (function not required if MSTVs are closed and deactivated)

Each of the above functions is interlocked with P-4 to avert or reduce the continued cooldown of the RCS following a reactor trip. An excessive cooldown of the RCS following a reactor trip could cause an insertion of positive reactivity with a subsequent increase in core power. Addition of feedwater to a steam generator associated with a steamline or feedline break could result in excessive containment building pressure.

To avoid such a situation, the noted Functions have been interlocked with P-4 as part of the design of the unit control and protection system.

The turbine trip Function is explicitly assumed in the non-LOCA analysis since it is an immediate consequence of the reactor trip Function. Block of the auto SI signals is required to support long-term ECCS operation in the post-LOCA recirculation mode.

The RTB position switches that provide input to the P-4 interlock only function to energize or de-energize or open or close contacts. Therefore, this Function has no adjustable trip setpoints with which to associate an Allowable Value.

This Function must be OPERABLE in MODES 1, 2, and 3, as noted above, when the reactor may be critical or approaching criticality or support of the auto SI block function is required. This Function does not have to be OPERABLE in MODES 4, 5, or 6 because the main turbine and the MFW System are not required to be in operation.

ESFAS I nstrumentat i on 3. 3. 2 Table 3.3.2-1 (page 4 o f 4)

Engineered Safety Feature Actuation System Instrumentation APPLICABLE MODES OR OTHER SPEC I F I ED REQUIRED SURVE I LLANCE ALLOWABLE FUNCT I ON COND I T I ONS CHANNELS COND I TI ONS REQU I REMENTS VALUE

6. Auxi I iary Feedwater

a. Automatic Actuation Logic and Actuation Relays

b. SG Water Level-Low Low

c. Safety Injection

d. Loss o f Offsite Power

e. Trip o f a l l Main Feedwater Pumps 7. Automatic Switchover t o Conta i nment Sump

a. Automat i c Actuat i on Log i c and Actuation Re I ays

b. Refueling Water Storage Tank (RWST) Leve I -Low Low Coincident with Safety I nj ect i on

8. ESFAS Interlocks

a. Reactor Trip, P-4

b. Pressurizer Pressure, P-11 C. TaVg-Low LOW, P-12 1, 2. 3 2 t r a i ns G

SR 3.3.2.2 NA SR 3.3.2.3 SR 3.3.2.5

1. 2, 3 3 per SG D

SR 3.3.2.1 t 17%

SR 3.3.2.4 SR 3.3.2.8 SR 3.3.2.9 Refer t o Function 1 (Safety Injection) f o r al I i n i t i a t i o n functions and requirements.

1, 2. 3 1 per bus, F

SR 3.3.2.6 2 2184 V 2 buses SR 3.3.2.8 SR 3.3.2.9 1, 2 2 per pump H

SR 3.3.2.7 NA SR 3.3.2.9 1, 2, 3, 4 2 t r a i ns C

SR 3.3.2.2 NA SR 3.3.2.3 SR 38.3.2.5

1. 2, 3, 4 4

I SR 3.3.2.1 t 18.4% and SR 3.3.2.4 2 2 0. 4 %

SR 3.3.2.8 SR 3.3.2.9 Refer t o Function 1 (Safety Injection) f o r a l I i n i t i a t i o n functions and requirements.

1, 2, 3 1 per train, F

SR 3.3.2.1 NA I

2 t r a i ns

1. 2, 3 3

J SR 3.3.2.1 2 2010 psig

1. 2. 3 1 per loop J

SR 3.3.2.1 t 542°F and SR 38.3.2.8 SR 3.3.2.8 I 5 4 5 " F North Anna Units 1 and 2 3. 3 11

ESFAS I nstrumentat i on B 3. 3. 2 BASES APPLICABLE SAFETY

8.

Enqineered Safety Feature Actuation System Interlocks (continued)

ANALYSES, LCO,

AND APPL I CAB I L I TY interlock Functions back up manual actions t o ensure bypassab I e functions are i n operat i on under the cond i t i ons assumed i n the safety ana I yses.

a. Enq i neered Safety Feature Actuation System I nter I ocks-Reactor T r i p, P-4 The P-4 interlock i s enabled when a reactor t r i p breaker (RTB) and i t s associated bypass breaker are open. Once the P-4 interlock i s enabled, automatic S I reinitiation i s blocked after a 60 second time delay.

Th is Function a I lows operators t o take manua I contro I o f SI systems after the i n i t i a l phase o f injection i s complete. Once SI is blocked, automatic actuation o f SI cannot occur unti I the RTBs have been manual ly closed, resetting the P-4 interlock. The functions o f the P-4 interlock are:

Purpose I

Required MODES I

Function Isolate MFW regu I a t i ng va I ves with coincident low Tavg Trip the main turbine Feedwater i so I a t i on Preventsexcessive coo I down, thereby Condition I I event does not propagate t o Condition 1 1 1 event 1, 2 1, 2 (continued)

North Anna Units 1 and 2 B 3.3.2-29

ESFAS I nstrumentat ion B 3.3.2 BASES APPLICABLE

8.

Enq i neered Safety Feature Actuat ion System I nter I ocks SAFETY (continued)

ANALYSES

LCO, AND

a. Enq i neered Safety Feature Actuation System-APPLICAB LlTY I nter I ocks-Reactor Trip, P-4 (cont i nued)

Function Prevent automatic reactuation o f SI a f t e r a manual reset o f S I Purpose A l lows a l ignment o f ECCS f o r recirculation mode, prevents subsequent inadvertent alignment t o i n j ect i on mode by auto SI Required MODES 1, 2, 3 (continued)

North Anna Units 1 and 2 B 3.3.2-30

ESFAS I nstrumentat i on B 3.3.2 BASES APPLICABLE

8.

Enqineered Safety Feature Actuation System Interlocks SAFETY (cont i nued)

ANALYSES, LCO, AND

a. Enq i neered Safety Feature Actuat ion System APPLICABILITY I nter I ocks-Reactor Tr i p, P-4 (cont i nued)

Function Reset h i gh f I ow setpo no-load va

1. SI-High flow i n steam n t t o ue Steam Two Steam Lines Coincident W i t h Steam Line Pressure - Low Purpose Ensures setpoint i s reset t o I ow/zero power reference value following plant t r i p, regardless o f turbine f i r s t stage pressure i nd i cat ion Requ i red MODES 1,. 2, 3 (function not required i f MSTVs are c I osed and deactivated)

2. SI -High Steam Flow in Two Steam Lines Coincident With Tavg - LOW LOW

3. Steam Line isolation -

H i gh Steam F I ow in Two Steam L i nes Coincident W i t h Steam Line Pressure - Low

4. Steam Line Isolation -

H i gh Steam F I ow in Two Steam L i nes Coincident W i t h Tavg - LOW LOW (continued)

North Anna Units 1 and 2 B 3.3.2-31

ESFAS I nstrumentat i on B 3.3.2 BASES

~

~

~

~

~

~

~

APPLICABLE 8,

Enq i neered Safety Feature Actuat ion System I nter I ocks SAFETY (cont i nued)

ANALYSES, LCO, AND

a. Ens i neered Safety Feature Actuation System APPLICABILITY I nter I ocks-Reactor T r i p, P-4 (cont i nued)

Function Purpose 1

Required MODES Prevent open i ng o f the MFW regu I a t i ng valves i f they were closed on SI or SG Water Level

- High High Sea I - i n feedwater isolation t o prevent inadvertent feeding o f depressur i zed SG 1, 2, 3 Each o f t h e above Functions is interlocked with P-4 t o avert or reduce the continued cooldown o f the RCS following a reactor t r i p. An excessive cooldown of the RCS f o l lowing a reactor t r i p could cause an insertion o f positive reactivity with a subsequent increase in core power. Addition o f feedwater t o a steam generator associated with a steamline or feedline break could result in excessive containment building pressure. To avoid such a situation, the noted Functions have been interlocked with P-4 as part o f the design o f the u n i t control and protection system.

The turbine t r i p Function is e x p l i c i t l y assumed in the non-LOCA analysis since i t i s an immediate consequence o f the reactor t r i p Function. Block o f the auto SI signals i s required t o support long-term ECCS operation i n the post-LOCA rec i rcu I at: i on mode.

The RTB position switches that provide input t o the P-4 interlock only function t o energize or de-energize or open or close contacts. Therefore, t h i s Function has no adjustable t r i p setpoint with which t o associate an Al lowable Value.

This Function must be OPERABLE in MODES 1, 2, and 3, as noted above, when the reactor may be c r i t i c a l or approaching c r i t i c a l i t y or support o f the (continued)

North Anna Units 1 and 2 B 3.3.2-32

ESFAS I nstrumentat i on B 3.3.2 BASES APPLICABLE

8.

Enqineered Safety Feature Actuation System Interlocks (continued)

LCO,

SAFETY ANALYSES AND APPL I CAB LlTY

a. Enq i neered Safety Feature Actuat ion System I nter I ocks-Reactor Tr i p, P-4 (cont i nued) auto S I block function i s required. This Function does not have t o be OPERABLE in MODES 4, 5, or 6 because the main turbine and the MFW System are not required t o be in operation.

b. Enq i neered Safety Feature Actuation System Inter locks-Pressur i zer Pressure, P-11 The P-11 interlock permits a normal u n i t cooldown and depressur i zat i on without actuation o f S I. With two-out-of -three pressur i zer pressure channe Is (d i scussed previous I y) I ess than the P-1 1 setpo i nt, the operator can manually block the Pressurizer Pressure-Low Low S I s i gna I. Add i t i ona I I y, the P-11 signal blocks the automatic opening o f t h e pressur i zer power operated re I i e f va I ves (PORVs).

With two-out-of-three pressurizer pressure channels above the P-11 setpo i nt, the Pressurizer Pressure-Low Low SI signal i s automatical ly enabled. The operator can also enable t h i s function by use o f t h e respective manual reset switches. The automatic opening capabi I i t y f o r the pressurizer PORVs is reinstated above the P-11 setpoint. The ECCS accumulator isolation valves w i l l receive an automatic open signal when pressurizer pressure exceeds the P-11 setpoint. The Allowable Value reflects only steady state instrument uncertainties.

This Function must be OPERABLE in MODES 1, 2, and 3 t o allow an orderly cooldown and depressurization o f the unit without the actuation o f S I. This Function does not have t o be OPERABLE in MODE 4, 5, or 6 because system pressure must already be below the P-11 setpoint f o r the requirements o f the heatup and cooldown curves t o be met.

c. Enqineered Safety Feature Actuation System I nter I ocks-T,,,-Low 4 Low, P-12 On i ncreas i ng reactor coo I ant temperature, the P-12 interlock reinstates SI on High Steam Flow Coincident (cont i nued)

North Anna Units 1 and 2 B 3.3.2-33