ML20072V587

From kanterella
Jump to navigation Jump to search
Amends 188 & 169 to Licenses NPF-4 & NPF-7,respectively, Revising Na 1 & 2 TS HHSI Surveillance Requirements by Removing Explicit Numerical Values & Replacing W/Broader non-numerical Requirements
ML20072V587
Person / Time
Site: North Anna  Dominion icon.png
Issue date: 09/06/1994
From: Mccree V
Office of Nuclear Reactor Regulation
To:
Shared Package
ML20072V590 List:
References
NUDOCS 9409200060
Download: ML20072V587 (18)
v • d • e


Text

_

vana -

c I

uIh l

k UNITED STATES 5

NUCLEAR REGULATORY COMMISSION k.

,/

WASHINGTON, D.C. 20555 4001 l

VIRGINIA ELECTRIC AND POWER' COMPANY I

OLD DOMINION ELECTRIC COOPERATIVE DOCKET NO. 50-338 NORTH ANNA POWER-STATION. UNIT NO. I AMENDMENT TO FACILITY OPERATING LICENSE

' Amendment No. 188 License No. NPF-4 1

1.-

The Nuclear Regulatory Commission (the Commission) has found that:

A.

The application for amendment by Virginia Electric and Power Company-l et al., (the licensee) dated March 30, 1994, complies with the-standards and requirements of the Atomic Energy Act of 1954, as amended-(the Act), and the Commission's rules and regulations set forth in 10 CFR Chapter I; i

B.

The facility will operate in conformity with the application, the-provisions of the Act, and the rules ar.d :egulations of the Commission;

'I C.

There is reasonable assurance (1) that the activities authorized by-this amendment can be conducted without endangering-the health and i

safety of the public, and (ii) that such activities will_ be conducted in compliance with the' Commission's regulations; j

D.

The issuance of this amendment will not be inimical'to the common defense and security or to the health and safety of-the public;- and E.

The issuance of this amendment is in accordance with'10 CFR Part 51 of the Commission's regulations and all applicable requirements have-been satisfied.

i l

.9409200060 940906 PDR ADOCK 05000338

.P PDR a

~

=

^

, 2.

Accordingly, the license is amended by changes to the Technical Speci-fications as indicated in the attachment to this license amendment, and paragraph 2.D.(2) of Facility Operating License No. NPF-4 is hereby amended to read as follows:

(2) Technical Spec'ifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No.188, are hereby incorporated in the license.

The licensee shall operate the facility in accordance with the Technical Specifications.

3.

This license amendment is effective as of its date of issuance and shall be implemented within 30 days.

FOR THE GE@ARREGULATORYCOMMISSION h

WR Victor M. M ree, Acting Director Project Dir ctorate 11-2 Division of,eactde-Projects - I/II Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: September 6, 1994 I

i j

l s

a

-~;

4 J

ATTACHMENT T0 LICENSE AMENDMENT NO. 188 TO FACILITY OPERATING LICENSE NO. NPF !

DOCKET NO. 50-338 Replace the following pages of the Appendix "A" Technical. Specifications with the enclosed pages' as indicated. The revised pages are identified.by amendment number and contain vertical lines indicating the area of change.

The corresponding overleaf pages are also provided to maintain document

{

completeness.

Remove Paaes Insert Paaes XIV

'XIV l

3/4 5-5

-3/4 5-5 B 3/4 5-2 B 3/4 5-2 i

8 3/4 5-3 B 3/4 5-3 a

i f

i 4

)

-l i

s t

-l 1

-. -~;-.,.

I INDEX BASES SECTION PAGE 3/4.3 INSTRUMENTATION 3/4.3.1 PROTECTIVE INSTRUMENTATION............................... B 3/4 3-1 3/4.3.2 ENGINEERED SAFETY FEATURE INSTRUMENTATION................ B 3/4 3-1 3/4.3.3 MONITORING INSTRUMENTATION............................... B 3/4 3-1 3/4.4 REACTOR COOLANT SYSTEM 3/4.4.1 REACTOR COOLANT LOOPS.................................... B 3/4 4-1 3/4.4.2 and 3/4.4.3 SAFETY VALVES................................. B 3/4 4-2 3/4.4.4 PRESSURIZER.............................................. B 3/4 4-2 3/4.4.5 STEAM GENERATORS......................................... B 3/4 4-3 3/4.4.6 REACTOR COOLANT SYSTEM LEAKAGE........................... B 3/4 4-4 3/4.4.7 CH EM I ST RY................................................ B 3 / 4 4 -5 3/4.4.8 SPECIFIC ACTIVITY........................................ B 3/4 4-5 3/4.4.9 PRESSURE / TEMPERATURE LIMITS.............................. B 3/4 4-6 3/4.4.10 STRUCTURAL INTEGRITY..................................... B 3/4 4-11 3/4.4.11 REACTOR VESSEL HEAD VENT................................. B 3/4 4-13 j

NORTH ANNA - UNIT 1 XIII Amendment No. 32,4/3, 64'

N BASES -

SECTION PAGE jfLi EMERGENCY CORE COOLING SYSTEMS mCCS) 3/4.5.1 A CCUMULATORS............................................................................ B 3/4 5 - 1 3/4.5.2 and 3/4.5.3 ECCS S UB S YSTEMS............................................................... B 3/4 5-1 3/4.5.4 BORON INJECTION SYSTEM.......................................................... B 3/4 5-3 l

3/4.5.5 REFUELING WATER STORAGE TANK (RWST)................................ B 3/4 5-3 JL4.5 CONTAINMENT SYSTEMS 3/4.6.1 CONTAINMENT..................................................................................... B 3/4 6-1 l

3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS............................. B 3/4 6-2 3/4.6.3 CONTAINhENT ISOLATION VALVES................................................ B 3/4 6-3 3/4.6.4 COMBUSTIBLE G AS CONTROL......................................................... B 3/4 6 l 3/4.6.5 SUBATMOSPHERIC PRESSURE CONTROL SYSTEM...................... B 3/4 6-4 l

NORTH ANNA - UNIT 1 XIV Amendment No. 48,188

EMERGENCY CORE COOLING SYSTEM SURVEILLANCE REQUIREMENTS (Continued) i 2.

Verifying that each of the following pumps start automatically upon receipt of a safetyinjection test signal:

a) Centrifugalchargingpump,and 2

b) Low head safety injection pump.

f.

By verifying that each of the following pumps develop the indicated discharge -

pressure (after subtracting suction pressure) on recirculation flow when tested pursuant to Specification 4.0.5.

1.

Centrifugal charging pump 22410 psig.

2.

I.ow head safety injection pump 2156 psig.

By verifying that the following manual valves requiring adjustment to prevent g.

pump " runout" and subsequent component damage are locked and tagged in the -

proper position forinjection:

i i

1.

Within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> following completion of any repositioning or maintenance on the valve when ECCS systems are required to be OPERABLE.

2. '

At least once per 18 months.

1. 1-SI-188 Loop A Cold Leg i
2. 1-SI-191 Loop B Cold leg
3. 1-SI-193 -loop C Cold Leg
4. 1-SI-203' Loop A Hot leg
5. 1-SI-204 Loop B Hot Leg.
6. 1-SI-205 Loop C Hot Leg h.

By performing a flow balance test, during shutdown, following completion of-

{

modifications to the ECCS subsystems that alter the subsystem flow characteristics and verifying that:

1 1.

For high head safety injection lines, with'a single pump running:

a) The sum of the injection line flow rates, excluding the highest flow rate, i

' is greater than or equal to the minimum flow rate required to =

1 demonstrate compliance with' 10 CFR 50.46, and -

b). The total pump flow rate is less than or equal to the evaluated pump runout limit.

.l 3

NORTH ANNA - UNIT 1 3/45-5

. Amendment No. 6,19, !?!,' !?6,188 i

3/4.5 EMERGENCY CORE COOLING SYSTEMS BASES 3/4.5.1 ACCUMULATORS The OPERABILITY of each RCS accumulator ensures that a sufficient volume of borated water will be immediately forced into the reactor core through each of the cold legs in the event the RCS pressure falls below the pressure of the accumulators. This initial surge of water into the core provides the initial cooling mechanism during large RCS pipe ruptures.

The limits on accumulator volume, boron concentration and pressure ensure that the assumptions used for accumulator injection in the safety analysis are met.

The accumulator power operated isolation valves are considered to be

" operating bypasses" in the context of IEEE Std. 279-1971, which requires that bypasses of a protective function be removed automatically whenever permissive conditions are not met.

In addition, as these accumulator isolation valves fail to meet single failure criteria, removal of power to the valves is required.

The limits for operation with an accumulator inoperable for any reason except an isolation valve closed minimizes the time exposure of the plant to a LOCA event occurring concurrent with failure of an additiorial accumulator which may result in unacceptable peak cladding temperature t.

If a closed isolation valve cannot be immediately opened, the full capability of one accumulator is not available and prompt action is required to place the reactor in a mode where this capability is not required.

3/4.5.2 and 3/4.5.3 ECCS SUBSYSTEMS l

The OPERABILITY of two independent ECCS subsystems ensures that suf-ficient emergency core cooling capability will be available in the event of a LOCA assuming the loss of one subsystem through any single failure consideration.

Either subsystem operating in conjunction with the-accumulators is capable of supplying sufficient core cooling to limit the peak cladding temperatures within acceptable limits for all post-ulated break sizes ranging from the double ended break of the largest RCS cold leg pipe downward.

In addition, each ECCS subsystem provides long term core cooling capability in the recirculation mode during the accident recovery period.

NORTH ANNA - UNIT 1 B 3/4 5-1

~

REACTIVITY CONTROL SYSTEMS BASES ECCS SUBSYSTEMS (Continued)

With the RCS temperature below 350 F, one OPERABLE ECCS subsystem is acceptable without single failure consideration on the basis of the stable reactivity condition of the reactor and the limited core cooling requirements.

The limitation for a maximum of one centrifugal charging pump and one low head safety injection pump to be OPERABLE and the Surveillance Requirement to verify all charging pum and low head safety injection pumps except the required OPERABLE pump to be inoperable below 316'F provides assurance that a mass addition pressure transient can be relieved by the operation of a single PORV.

The Surveillance Requirements provided to ensure OPERABILITY of each component ensures that at a minimum, the assumptions used in the safety analyses are met and that subsyste OPERABILITY is maintained.

i In the event of modifications to an ECCS subsystem that could alter the subsystem flow characteristics, a flow balance test shall be performed. The flow balance test criteria are estab-lished based on the system performance assumed in the safety analysis (minimum flow limit) and on HHSI pump runout protection (maximum flow limit). In performing the flow balance, the l

effects of flow measurement instrument uncertainties accounting for system configuration and the variability between installed pumps must be properly considered.

i Numerical acceptance criteria for the flow balance test are specified in the surveillance test procedure. These criteria are established based on the following considerations:

1) The totalinjected flow to the core (assuming spillage of the branch line with the highest flow) must meet or exceed that assumed in the safety analysis. The limiting safety analysis is the loss of coolant accident (LOCA) analysis. This criterion may vary, 1

particularly since the inputs to the safety analysis controlled by LCO 6.9.1.7 may vary with reload cycle. The safety analysis flow requirements are thus established by the currently applicable LOCA analysis which has demonstrated compliance with the ECCS acceptance limits of 10 CFR 50.46.

2) De total pumped flow must be less than the HHSIpump runout limit. This flow varies with the specific HHSI pump assumed to operate during the accident. Since the HHSI i

pumps also function as normal charging pumps, their characteristics, including runout limits, will vary over service life.

3) ne requirements for reactor coolan't pump seal injection must be met during normal operation, and the effects of seal injection during accidents must be considered in meeting constraints 1) and 2) above.

{

NORTH ANNA - UNIT 1 B 3/4 5 2 Amendment No.16,68, !!?,170,188

'l

e v

EMERGENCY CORE COOI ING SYSTEMS e

BASES G

3/4.5.4 BORON INJECTION SYSTEM The OPERABILITY of the boron injection system as part of the ECCS ensures that sufficient negative reactivity is injected into the core to counteract any positive increase in reactivity caused by RCS system cooldown. RCS cooldown can be caused by inadvertent depressurization, a loss-of-coolant accident or a steam line rupture.

e The limits on injection tank minimum contained volume and boron concentration ensure.

that the assumptions used in the steam line break analysis are met.

'Ihe OPERABILITY of the tedundant heat tracing channels associated with the boron injection system ensure that the solubility of the boron solution will be maintained above the solubility limit of 111*F at 15,750 ppm boron.

3/4.5.5 REFUEI ING WATER STORAGE TANK The OPERABILITY of the RWST as part of the ECCS ensures that a sufficient supply of borated water is available for injection by the ECCS in the event of a LOCA. The limits on RWST.

i minimum volume and boron concentration ensure that 1) sufficient wateris available within '

containment to permit recirculation cooling flow to the core, and 2) the reactor will remain l

suberitical in the cold condition following mixing of the RWST and the RCS water volumes with all control rods inserted except for the most reactive control assembly. These assumptions are.

consistent with the LOCA analyses.

The contained water volume limit includes an allowance for water not usable because of tank discharge line location or other physical characteristics.

The limits on contained water volume and boron concentration of the RWST also ensure a pH value of between 8.5 and 11.0 for quench spray and between 7.7 and 9.0 for the solution recirculated within the containment after a LOCA. This pH minimizes the evolution ofiodine and minimizes the effect of chloride and caustic stress corrosion on mechanical systems and '

components.

An RWST wide range level instrument loop ;ncertainty was included in the safety analysis and therefore need not be considered by the operator.

i i

NORTH ANNA - UNIT 1 B 3/4 5 3 Amendment No. M,93, !!O.188

_,+' * " q,,4 e-4 S

- UNITED STATES

-E NUCLEAR REGULATORY COMMISSION

%.....,/ -

wAssinoTon. o.c. nosss-oooi VIRGINIA ELECTRIC AND POWER COMPANY OLD DOMINION ELECTRIC COOPERATIVE DOCKET NO. 50-339 HDRTH ANNA POWER STATION. UNIT NO. 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 169 License No. NPF-7

't 1.

The Nuclear Regulatory Commission (the Commission) has found that:

A.

The application for amendment by Virginia Electric and Power Company et al., (the licensee) dated March 30, 1994, complies with the l

standards and requirements of the Atomic Energy Act.of 1954, as amended (the Act), and the Commissinn's rules and regulations set forth in 10 CFR Chapter I; B.

The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; 1

C.

There is reasonable assurance (i) that the activities authorizea by-this amendment can be conducted without endangering the health and safety of the public, and-(ii) that such activities will be conducted in compliance with the Commission's regulations; 3

D.

-The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.

The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

l

' i 1

1 1

w a

.j l

o

= '

)

12.

Accordingly, the license is amended by changes to the Technical Speci-l

-P' fications as indicated in the attachment to this license amendment, and 1

paragraph 2.C.(2) of Facility Operating License No. NPF-7 is hereby i

amended to read as follows:

l (2) Technical Specificatioqi The Technical Specifications contained in Appendices A and B, as '

revised through Amendment No.169

, are hereby incorporated in the license. The licensee shall operate the facility in accordance

]'

with the Technical Specifications.

i 3.

This license amendment is effective as of its date of issuance and shall be implemented within 30 days.

j FOR THE EAR REGULATORY COMMISSION Victor M. Mc ee, ting Director Project Dire torat 11-2 Division of Reacto Projects - I/II Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications 1

Date of Issuance: September 6, 1994 6

7 i

[t i

4 ATTACHMENT TO LICENSE AMENDMENT N0. 169 TO FACILITY OPERATING LICENSE NO. NPF-7 DOCKET NO. 50-339 Replace the following pages of the Appendix "A" Technical Specifications with the enclosed pages as indicated.

The revised pages are identified by amendment number and contain vertical lines indicating the area of change.

The corresponding overleaf pages are also provided to maintain document completeness.

Remove 9 aces Insert Paaes XII XII 3/4 5-5 3/4 5-5 B 3/4 5-2 B 3/4 5-2 B 3/4 5-3 B 3/4 5-3 4

i INDEX BASES

.SECTION PAGE l

3/4.3 INSTRUMENTATION 3/4.3.1 and 3/4.3.2 PROTECTIVE AND ENGINEERED SAFETY FEATURES (ESF) INSTRUMENTATION....

B 3/4 3-1 1

3/4.3.3 MONITORING INSTRUMENTATION.

B 3/4 3-1 3/4.4 REACTOR COOLANT SYSTEM 3/4.4.1 REACTOR COOLANT LOOPS AND COOLANT CIRCULATION..

B 3/4 4-1

)

l 1

3/4.4.2 and 3/4.4.3 SAFETY AND RELIEF VALVES....

B 3/4 4-2 3/4.4.4 PRESSURIZER................

B 3/4 4-2 3/4.4.5 STEAM GENERATORS...

B 3/4 4-3 3/4.4.6 REACTOR COOLANT SYSTEM LEAKAGE................

B 3/4 4-4 i

l 3/4.4.7 CHEMISTRY.

B 3/4 4-5 l...

-3/4.4.8 SPECIFIC ACTIVITY.....................................

B 3/4 4 3/4.4.9 PRESSURE / TEMPERATURE LIMITS.

B 3/4 4-6 i

1-3/4.4.10 STRUCTURAL INTEGRITY...

Be J 4-16 3/4.4.11 REACTOR VESSEL HEAD VENT................................

B 3/4 4-17 l

l

' NORTH ANNA - UNIT 2 XI Amendment No. 49 I

INDEX BASES SECTION PAGE i

31.1.1 EMERGENCY CORE COOLING SYSTEMS (ECCS) 3/4.5.1 ACCUMULA'IORS................................................................ B 3/4 5 1 3/4.5.2 and 3/4.5.3 ECCS SUBSYSTEMS................................................................... B 3/4 5-1 3/4.5.4 BORON INJECrlON SYSTEM........................................................ B 3/4 5-3

.l 3/4.5.5 REFUELING WATER STORAGE TANK (RWST)............................... B 3/4 5 3 a

3/.16 CONTAWMENT SYSN 3/4.6.1 CONTAINMENT

................................................................B3/46-1 l

3/4.6.2 DEPRESSURIZA'I1ON AND COOLING SYSTEMS............................. B 3/4 6-3 3/4.6.3 CONTAINMENT ISOLATION VALVES............................................... B 3/4 6-3 3/4.6.4 COMBUSTIBLE GAS CONTROL..................................................... B 3/4 6 4 3/4.6.5 SUBATMOSPHERIC PRESSURE CONTROL SYSTEM...................... B 3/4 6-4 -l t

i i

-)

l i

1 1

1 l

i

)

.l 1

l j

1

-l l

NORTH ANNA - UNIT 2 XH Amendment ?lo. 169 j

i

.~

.... ~ ~

=. -..

t

^

,+

l EMERGENCY CORE CODIlNG SYSTEM

-(

SURVEILLANCE REQUIREMENTS (Continued)

\\

f.

~ By verifying that each of the following pumps develop the indicated discharge l

pressure (after subtracting suction pressure) on recirculation flow when_ tested.'

pursuant to Specification 4.0.5.

I 1.

Centrifugal charging pump greater than or equal to 2410 psig.

,l 2.

Low head safety injection pump greater than or equal to 156 psig.'

g.

By verifying that the following manual valves requiring adjustment to prevent -

pump " runout" and subsequent component damage are locked and tagged in the.

j

.a properposition forinjection:

t 1.

Within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> following completion of any repositioning or maintenance on the valve when the ECCS systems are required to be OPERABLE.

2.

At least once per 18 months.

1. 2-SI-89 Loop A Coldleg
2. 2-SI-97 Loop B Cold Leg
3. 2-SI-103 Loop C Coldleg
4. 2-SI-116 Loop A Hot Leg-

'i

5. 2-SI-111 Loop B Hot Leg
6. 2-SI-123 ' loop C Hot leg i

h.

By performing a flow balance test, during shutdown, following completion of -

modifications to the ECCS subsystems that alter the subsystem flow characteristics and verifying that:

1.

For high head safety injection lines, with a single pump running:

a) The sum of the injection line flow rates, excluding the highest flow rate, is greater than or equal to the minimum flow rate required to demonstrate compliance with 10 CFR 50.46, and i

b) The total pump flow rate is less than'or equal to the evaluated pump -

-i runout limit.

~'

.1 is a

I.4 NORTH ANNA - UNIT 2..

i 3/45-5 Amendment No. 454r4H,169

3/4.5 EMERGENCY CORE COOLING SYSTEMS e

BASES 3

3/4.5.1 ACCUMULATORS The OPERABILITY of each RCS accumulator ensures that a sufficient volume of borated water will be immediately forced into the reactor core through.

1 each of the cold legs in the event the RCS pressure falls below the l

pressure of the accumulators. This initial surge of water into the core provides the initial cooling mechanism during large RCS pipe ruptures.

The limits on accumulator volume, boron concentration and pressure ensure that the assumptions used for accumulator injection in the safety analysis are met.

The accumulator power operated isolation valves are considered to be

" operating bypasses" in the context of IEEE Std. 279-1971, which requires that bypasses of a protective functicn be removed automatically whenever permissive conditions are not met.

In addition, as these accumulator 1 solation valves fail to meet single failure criteria, removal of power to the valves.is required.

The limits for operation with an accumulator inoperable for any reason -

except an isolation valve closed minimizes the time exposure of.the plant to a LOCA event occurring concurrent with failure of an additional accumulator which may result in unacceptable peak cladding temperatures.

If a closed isolation valve cannot be immediately opened, the full

. capability of one accumulator is not available and ~ prompt action is required to place the reactor in a mode where this capability is not required.

3/4.5.2 and 3/4.5.3 ECCS SUBSYSTEMS

- The OPERABILITY of two independent ECCS-subsystems ensures that suf--

ficient emergency. core cooling capability will be available in'the event.

of a LOCA assuming the loss of one subsystem through any> single. failure consideration'. Either subsystem operating in conjunction-with-the accumulators is capable of supplying sufficient core cooling to limit the peak cladding temperatures'within acceptable lirits for all post-

~ulated break sizes ranging from the double ended break of the largest' RCS' cold leg pipe downward.

In addition,'each ECC5-subsystem provides long' term core cooling capability in the recirculation mode during the accident recovery period.

t

..t NORTH ANNA - UNIT.2 B 3/4 5-1 5

h f

~

i l

\\

REACTTVITY CONTROL SYSTEMS BASES 1

ECCS SUBSYSTEMS (Continiwh With the RCS temperature below 350'F, one OPERABLE ECCS subsystem is acceptable without single failure consideration on the basis of the stable reactivity condition of the reactor and the limited core cooling requirements.

\\

The limitation for a maximum of one centrifugal charging pump and one low head safety _

injection pump to be OPERABLE and the Surveillance Requirement to verify all charging pumps i

and low head safety injection pumps except the required OPERABLE pump to be inoperable below 358'F pmvides assurance that a mass addition pressure transient can be relieved by the.

i operation of a single PORV.

The Surveillance Requirements provided to ensure OPERABILITY of each component

{

ensures that at a minimum, the assumptions used in the safety analyses are met and that subsystem.

OPERABILITY is maintained.

l In the event of modifications to an ECCS subsystem that could alter the subsystem flow -

characteristics, a flow balance test shall be performed. The flow balance test criteria are 1

. established based on the system performance assumed in the safety analysis (minimum flow limit) ~

and on HHSI pump runout protection (maximum flow limit). In performing the flow balance, the -

i effects of flow measurement instrument uncertainties accounting for system configuration and the j

variability between installed pumps must be properly considered.

~

Numerical acceptance criteria for the flow balance test are specified in the surveillance test procedure. These criteria are established based on the following considerations:

1) The totalinjected flow to the core (assuming spillage of the branch line with the highest -

flow) must meet or exceed that assumed in the snfety analysis. De limiting safety 1

analysis is the loss of coolant accident (LOCA) analysis, nis criterion may vary, j

panicularly since the inputs to the safety analysis controlled by LCO 6.9.1.7 may vary with reload cycle. The safety analysis flow requirements are thus established by the -

l cunently applicable LOCA analysis which has demonstrated compliance with the ECCS acceptance limits of 10 CFR 50.46.

J

2) The total pumped flow must be less than the HHSI pump runout limit. This flow varies with the specific HHSI pump anumed to operate during the accident. Since the HHSI pumps also function as normal charging pumps, their characteristics, including runout limits, will vary over service life.
o..
3) ne requirements for reactor coolant pump seal injection must be met during normal operation, and the effects of seal injection during accidents must be considered in meeting constraints I) and 2) above.

j 1

NORTH ANNA UNIT 2 B 3/4 5 2 Amendment No. 54, "",169 g g,

y.

m

EMERGENCY CORE COOLING SYSTEMS BASES 3/4.5.4 BORON INJECTION SYSTEM The OPERABILITY of the boron injection system as part of the ECCS ensures that sufficient negative reactivity is injected into the core to counteract any positive increase in reactivity caused by RCS system cooldown. RCS cooldown can be caused by inadvertent depressurization, a loss-of-coolant accident or a steam line rupture.

The limits on injection tank minimum contained volume and boron concentration ensure that the assumptions used in the steam line break analysis are met. The contained water volume limit includes an allowance for water not usttble because of tank discharge line location or other physical characteristics.

The OPERABILITY of the redundant heat tracing channels associated with the boron injection system ensure that the solubility of the boron solution will be maintained above the solubility limit of 111*F at 15,750 ppm boron.

3/4.5.5 REFUELING WATER STDRAGE TANK The OPERABILITY of the RWST as part of the ECCS ensures that a sufficient supply of borated wateris available for injection by the ECCS in the event of a LOCA. The limits on RWST minimum volume and boron concentration ensure that 1) sufficient water is available within containment to permit rectreulation cooling flow to the core, and 2) the reactor will remain suberitical in the cold condition following mixing of the RWST and the RCS water volumes with all control rods inserted except for the most reactive control assembly. These assumptions are consistent with the LOCA analyses.

The contained water volume limit includes an allowance for water not usable because of tank discharge line location or other physical characteristics.

The limits on contained water volume and boron concentration of the RWST also ensure a pH value of between 8.5 and 11.0 for quench spray and between 7.7 and 9.0 for the solution recirculated within the containment after a ? TOA. This pH minimizes the evolution ofiodine and minimizes the effect of chloride and caustic stress corrosion on mechanical systems and components.

An RWST wide range level instrument loop uncertainty was included in the safety analysis and therefore need not be considered by the operator.

' NORTH ANNA - UNIT 2 B3/45-3 Amendment hlo. Mr96,159

,

Retrieved from "https://kanterella.com/w/index.php?title=ML20072V587&oldid=4407245"