Text

Proposed Tech Specs Re 24-month Fuel Cycle Surveillance Extensions for ECCS
	ML20086K317
Person / Time
Site:	Millstone
Issue date:	07/14/1995
From:	; NORTHEAST NUCLEAR ENERGY CO.
To:	;
Shared Package
ML20086K295	List: B15296, Application for Amend to License NPF-49 Re 24-month Fuel Cycle Surveillance Extensions for ECCS; ML20086K317;
References
	NUDOCS 9507200097
	Download: ML20086K317 (31)
	v • d • e

, _ _ . _.

w 4'

Millstone Nuclear Power Station, Unit No. 3 Proposed Revision to Technical Specifications 24-Month Fuel Cycle Page Number and Section Title Amendment Number.

4.5.2.d ECCS -Surveillance Requirements 3/4 5-4, Amendment 100 4'.5.2.e ECCS -Surveillance Requirements 3/4 5-5 Amendment 60 4.5.2.g.2 ECCS -Surveillance Requirements 3/4 5-5 Amendment 60 4.5.2.h ECCS -Surveillance Requirements 3/4 5-6 Amendment 60 4.5.5 ECCS--Surveillance Requirements 3/4 5-10*

pH Trisodium Phosphate Storage Amendment 115

$No changes are required. This page is provided for information only.

l 1

9507200097 950714 3 PDR ADOCK 0500

, P

.~ .

]-

stEtaENCY CORE C00LTHS SYSTEMS SURVEILLANCE REQUIREMENTS 4.5.2 Each ECCS subsystem shall be demonstrated OPERABLE:

a. At least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months by verifying that the following valves are in the indicated positions with power to the valve operators removed:

Valve Number Valve Function Valve Position 3SIH*MV8806 RWST Supply to SI Pumps OPEN 3SIH*MV8802A SI Pump A to Hot Leg Injection CLOSED 3SIH*MV8802B SI Pump B to Hot Leg Injection CLOSED 3SIH*MV8835 SI Cold Leg Master Isolation OPEN 3SIH*MV8813 SI Pump Master Miniflow OPEN Isolation 3SIL*MV8840 RHR to Hot Leg Injection CLOSED 3SIL*MV8809A RHR Pump A to Cold Leg OPEN Injection 3SIL*MV88098 RHR Pump B to Cold Leg OPEN Injection

b. At least once per 31 days by:

1) Verifying that the ECCS piping, except for the RSS pump, heat exchanger and associated piping, is full of water by venting the ECCS pump casings and accessible discharge piping high points, and

2) Verifying that each valve (manual, power-operated, or automatic) in the flow path that is not locked, sealed, or otherwise secured in position, is in its correct position.

c. rags, By a visual trash, inspection clothing, which inverifies etc.) is present that no loose the containment whichdebris cou (ld be transported to the containment sump and cause restriction of the aump suctions durir.g LOCA conditions. This visual inspection shall m performed:

1) For all accessible areas of the containment prior to establish-ing CONTAINMENT INTEGRITY, and

2) At least once daily of the areas affected (during each day) within containment by containment entry and during the final i entry when CONTAINMENT INTEGRITY is established.

d.

ga RE.s usi.irJ c, W ratw Ai At least once ger 18 monthslby: l

1) Verifying automatic interlock action of the RHR System from the Reactor Coolant System by ensuring that with a simulated or actual Reactor Coolant System pressure signal greater than or equal to 390 psia the interlocks prevent the valves from being opened.

N LLSTONE - UNIT 3 3/4 5-4 Amendment No. #, 77,100 cpf

w . .

= h 11, ivy 2

. EMERGENCY CORE COOLING SYSTEMS "

{

. SURVEILLANCE REOUIREMENTS (Continued) -

+

2) A visual inspection of the containment sump and verifying that the subsystem suction inlets are not restricted by debris and i that the sump components (trash racks, screens, etc.) show no evidence of structural distress or abnormal corrosion.

ecb REF u tucc, xmano w

e. At least once Fer 18 months, during shutdowT, by:

1) Verifying that each automatic valve in the flow path actuates to its correct position on a Safety Injection actuation test signal, and

2) Verifying that each of the following pumps start automatically upon receipt of a Safety Injection actuation test signal: ;

a) ' Centrifugal charging pump, l

b) Safety Injection pump, and c) RHR pump.

3) Verifying that the Residual Heat Removal pumps stop automatically upon receipt of a Low-Low RWST Level test signal. .

f. By verifying that each of the following pumps develop:, the indicated differential pressure on recirculation flow when tested pursuant to :

Specification 4.0.5:

1) Centrifugal charging pump 1 2411 psid,

2) Safety Injection pump 2 1348 psid,

3) RHR pump 2 165 psid, and

4) Containment recirculation pump 1 130 psid.

g. By verifying the correct position of each electrical and/or mechanical position stop for the following ECCS throttle valves: -

1) Within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months following completion of each valve stroking operation or maintenance on the valve when the ECCS subsystems are required to be OPERABLE, and

2) At least once fer 18 monthsh EAch ARFU EWC- WEW-ECCS Throttle Valves Valve Mumber Yalve Number 3SIH*V6 3SIH*V25 :

3SIH*V7 3SIH*V27 MILLSTONE - UNIT 3 3/4 5-5 Amendment No. 60 son:

Y - . - - . . _ _ ._ _ ., . _ ___ _ . _ _ . . _ _ ~ . - _

i

. .t::t n, M EMERGENCY CORE COOLING SYSTEMS- -

SURVEILLANCE REOUIREMENTS (Continued) p!

ECCS Throttle Valves Valve Number Valve Number 3SIH*V8 3SIH*V107 3SIH*Y? 3SIH*V108 3SIH*V21 3SIH*V109 3SIH*V23 3SIH*V111

h. By performing a flow balance test,(durino shutdoD following com-pletion of modifications to the ECCS subsystems that alter the subsystem flow characteristics and verifying that: <

1) For centrifugal charging pump 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 339 gpm, and b) The total pump flow rate is less than or equal to 560 gpm.

2) For Safety Injection pump 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 442.5 gpm, and -

b) The total pump flow rate is less than or equal to 670 gpm for the A pump and 650 gpm for the B pump.

3) For RHR pump lines, with a single pump running, the sum of the injection line flow rates is greater than or equal to 3976 gpm.

i i

1 l

.M MILLSTONE - UNIT 3 3/4 5-6 Amenament No. 60 l

$Nr

. . -May 2o, iGS5

.b ^

. ENERGENCY CORE C0OLING SYSTEMS 1[ I -

3/4.5.5 pH TRIS 0DIUM PHGSPHATE STORAGE BASKETS

)

LIMITING Cole! TION FOR OPERATION

, 3.5.5 The trisodium phosphate (TSP) dodecahydrate Storage Baskets shall be OPERABLE.

APPLICABILITY: N0 DES 1, 2, 3 and 4 ACTION:

With the TSP Storage Baskets inoperable, restore the system TSP Storage Baskets to OPERABLE status within 7 days or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in HOT SHUTDOWN the following 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

SURVEILLANCE REQUIREMENTS 4.5.5 The TSP Storage Baskets shall be demonstrated OPERABLE at least once each REFUELING INTERVAL by verifying that a minimum total of 974 cubic feet of TSP is contained in the TSP Storage Baskets.

9 3

)

MILLSTONE UNIT No. 3 3/4 5-10 Amendment No.115 eno:

L. _ _ _ . _ __ __ . . _ _ _ _ _ _ _ _ . . __

.= .. _.. .

d l

Docket No. 50-423 B15296 t

t t

I Attachment 2 l Millstone Nuclear Power Station, Unit No. 3 Proposed Revision to Technical Specifications 24-Month Fuel Cycle Emergency Core Cooling Systems Surveillance Extensions Retyped Pages ,

t 6

E July 1995 !

4 EMERGENCY CORE COOLING SYSTEMS SURVEILLANCE REQUIREMENTS 4.5.2 Each ECCS subsystem shall be demonstrated OPERABLE:

a. At least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months by verifying that the following valves are in the indicated positions with power to the valve operators removed:

Valve Number Valve Function Valve Position 3SIH*MV8806 RWST Supply to SI Pumps OPEN 3SIH*MV8802A SI Pump A to Hot Leg Injection CLOSED 3SIH*MV88028 SI Pump B to Hot Leg Injection CLOSED 3SIH*MV883S SI Cold Leg Master Isolation OPEN 3SIH*MV8813 SI Pump Master Miniflow OPEN Isolation 3SIL*MV8840 RHR to Hot Leg Injection CLOSED 3SIL*MV8809A RHR Pump A to Cold Leg OPEN Injection 3SIL*MV8809B RHR Pump B to Cold Leg OPEN Injection

b. At leas' per 31 days by:

1) Verii,y tog that the ECCS piping, except for the RSS pump, heat exchanger and associated piping, is full of water by venting the ECCS pump casings and accessible discharge piping high points, and

2) Verifying that each valve (manual, power-operated, or automatic) in the flow path that is not locked, sealed, or otherwise secured in position, is in its correct position.

c. By a visual inspection which verifies that no loose debris (rags, trash, clothing, etc.) is present in the containment which could be transported to the containment sump and cause restriction of the pump suctions during LOCA conditions. This visual inspection shall be performed:

I) For all accessible areas of the containment prior to establish-ing CONTAINMENT INTEGRITY, and

2) At least once daily of the areas affected (during each day) within containment by containment entry and during the final entry when CONTAINMENT INTEGRITY is established.

d. At least once each REFUELING INTERVAL by:

l I) Verifying automatic interlock action of the RHR System from the Reactor Coolant System by ensuring that with a simulated or actual Reactor Coolant System pressure signal greater than or equal to 390 psia the interlocks prevent the valves from being opened.

MILLSTONE - UNIT 3 3/4 5-4 osos Amendment No. 79, /f, 199,

,-- i

.e: ,

EMERGENCY CORE C0OLING SYSTEMS SURVEILLANCE REQUIREMENTS (Continued) ;

2) A visual inspection of the containment sump and verifying that l the subsystem suction inlets are not restricted by debris and :

that the sump components (trash racks, screens, etc.) show no ,

evidence of structural distress or abnormal corrosion. ,

e. At least once each REFUELING INTERVAL by: l-

1) Verifying that each automatic valve in the flow path actuates to i its correct position on a Safety Injection actuation test signal,-

and l

2) Verifying that each of the following pumps start automatically upon receipt of a Safety Injection actuation test signal: i a) Centrifugal charging pump, !

i b) Safety Injection pump, and i

c) RHR pump.

4

3) Verifying that the Residual Heat Removal pumps stop automatically upon receipt of a Low-Low RWST Level test signal. <

'I

f. By verifying that each of the following pumps develops the indicated ,

differential pressure on recirculation flow when tested pursuant to !

Specification 4.0.5: -l

1) Centrifugal charging pump 2 2411 psid,

2) Safety Injection pump 2 1348 psid,

3) RHR pump 2 165 psid, and I

4) Containment recirculation pump 2 130 psid. 1 l

g. By verifying the correct position of each electrical and/or mechanical ,

position stop for the following ECCS throttle valves: l

1) Within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months following completion of each valve stroking operation or maintenance on the valve when the ECCS subsystems ,

are required to be OPERABLE, and

2) At least once each REFUELING INTERVAL. l ,

ECCS Throttle Valves Valve Number Valve Number 3SIH*V6 3SIH*V25 3SIH*V7 3SIH*V27 NILLSTONE - UNIT 3 3/4 5-5 Amendment No. pp, om L

, EMERGENCY CORE C0OLING SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

I ECCS Throttle Valves

! Valve Number Valve Number 3SIH*V8 3SIH*V107 3SIH*V9 3SIH*V108 3SIH*V21 3SIH*V109 3SIH*V23 3SIH*V111

h. By performing a flow balance test following completion of modifications to the ECCS subsystems that alter the subsystem l flow characteristics and verifying that:

1) For centrifugal charging pump 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 339 gpm, and 1

b) The total pump flow rate is less than or equal to 560 l gpm.

l 2) For Safety Injection pump 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 442.5 gpm, and l b) The total pump flow rate is less than or equal to 670 gpm for the A pump and 650 gpm for the B pump.

3) For RHR pump lines, with a single pump running, the sum of the )

injection line flow rates is greater than or equal to 3976 gpm.

1 MILLSTONE - UNIT 3 3/4 5-6 Amendment No. J7, o40s L... .. ..

j i

l

\

\

Docket No. 50-423 B15296 I

')

i

.'1 l

i Attachment 3 l Millstone Nuclear Power Station, Unit No. 3 i Proposed Revision to Technical Specifications 24-Month Fuel Cycle "

Emergency Core Cooling Systems Surveillance Extensions :

1 Description of the Proposed Technical Specification changes i i

l l

I l

]

July 1995

4

U. S. Nuclear Regulatory Commission B15296/ Attachment 3/Page 1 July 14, 1995 Millstone Nuclear Power Station, Unit No. 3 l Description of the Proposed Technical l Specification Changes j l

Introduction On June 7, 1995, Millstone Unit No. 3 began operating on a ,

nominal-24-month fuel cycle instead of the previous 18-month fuel' cycle. To take advantage of this longer fuel cycle, Northeast

' Nuclear Energy Company (NNECO) is proposing to modify the frequency of a number of the surveillance requirements-existing in the Millstone Unit No. 3 Technical Specifications. The proposed changes are described below:

1. Section 4.5.2.d.1 and 4.5.2.d.2, ECCS Subsystem Surveillance Requirements Surveillance Requirement 4.5.2.d.1 verifies automatic interlock action of the residual heat removal (RHR) system from the reactor coolant system (RCS) by ensuring that with a simulated or actual (RHR) pressure signal greater than or equal to 390 psia the interlocks prevent the valves from being opened. Surveillance Requirement 4.5.2.d.2. requires a~ l visual inspection of the containment sump and it also j verifies that the subsystem suction inlets are not restricted j by debris and that the sump components show no evidence of )

structural distress or abnormal corrosion. Both of these surveillances are required to be performed at least once per 18 months. NNECO proposes to extend the frequency of j Surveillance Requirements 4.5.2.d.1 and 4.5.2.d.2 to at least i once each refueling interval (i.e.,. nominal 24' months).

2. Section 4.5.2.e.1, 2, and 3, and 4.5.2.h, ECCS Subsystem Surveillance Requirements Surveillance Requirement 4.5.2.e.1 verifies the operability of each automatic valve in the ECCS injection flow path to ensure adequate - core cooling during the injection phase of the accident. Surveillance Requirement 4.5.2.e.2 verifies the operability of each pump in the charging system,. safety injection system and the RHR system by verifying that each pump starts automatically upon receipt of a safety injection actuation test signal. Surveillance Requirement 4.5.2.e.3 verifies that the RHR pumps stop automatically upon receipt of a low-low refueling water storage tank (RWST) test signal.

These surveillances are required to be performed during shutdown at least once per 18 months. NNECO proposes to extend the irequency of Surveillance Requirements 4.5.2.e.1, 4.5.2.e.2 and 4.5.2.e.3 from at least once per'18 months to

O l

U. S. Nuclear Regulatory Commission B15296/ Attachment 3/Page 2 July 14, 1995 at least once each refueling interval (i.e., nominal 24 months). In addition, the phrase "during shutdown" in Surveillance Requirement 4.5.2.e and. 4.5.2.h is being deleted. Because the terms " hot shutdown" and " cold shutdown" are defined in the Millstone Unit No. 3 Technical Specifications as operating modes or conditions, the added restriction to perform certain surveillances may be misinterpreted. This change is consistent with the guidance provided in Generic Letter 91-04.

3. Section 4.5.2.g.2, ECCS Subsystem, Surveillance Requirements Surveillance Requirement 4.5.2.g.2 verifies the correct position of each electrical and/or mechanical position stop for the ECCS throttle valves once per 18 months. NNECO proposes to extend the frequency of surveillance requirement 4.5.2.g.2 from at least once per 18 months to at least once per refueling interval (i.e., nominal 24 months).

4. Section 4.5.5, pH Trisodium Phosphate Storage Baskets, Surveillance Requirements Surveillance Requirement 4.5.5 requires that the trisodium phosphate (TSP) baskets shall be demonstrated operable at least once each refueling interval by verifying that a minimum total of 974 cubic feet of TSP is contained in the TSP storage baskets. Presently, a refueling interval is defined as at least once per 18 months. NNECO is proposing to extend the . frequency of surveillance requirement 4.5.5 from at least once per 18 months to at least once per refueling interval (i.e., nominal 24 months). No wording changes are required to Surveillance Requirement 4.5.5.

w

Dagket No. 50-423 B15296 Attachment 4 Millstone Nuclear Power Station, Unit No. 3 Proposed Revision to Technical Specifications 24-Month Fuel Cycle Emergency ~ Core Cooling Systems Surveillance Extensions Safety Assessment and Significant Hazards Consideration for Changes to:

-- ECCS Subsystems--Tavg Greater Than or Equal to 350' F

-- pH Trisodium Phosphate Storage Baskets July 1995 i

y..

}ll a

. .. 'c .

l U. S. Nuclear Regulatory Commission B15296/ Attachment 4/Page 1 :

July 14, 1995

{

l I

Millstone Nuclear Power Station, Unit No. 3 Proposed Revision to Technic 41 Specifications 24-Month Refuel Cycle Emergency Core Cooling Systems Surveillance Extensions ;

Safety Assessment and Significant Basards Consideration {

l SAFETY ASSESSMENT AND SIGNIFICANT R& BARDS- CONSIDERATION FOR CHANGES TO mMERGENCY CORE COOLING SYSTEMS SURVEILLANCE !

REQUIREMENTS l

Background

On June 7, 1995, Millstone Unit No. 3 began operating on a j nominal 24-month fuel cycle instead of the previous 18-month !

cycle. To be consistent with this longer fuel cycle, Northeast Nuclear Energy Company (NNECO) is proposing to modify the frequency of a number of surveillance requirements existing in the Millstone Unit No. 3 Technical Specifications. The safety assessment and significant hazards consideration for the proposed changes to-Sections 4.5.2 (ECCS Subsystems--Tavg Greater than 350" F) and '4.5.5 (pH Trisodium Phosphate Storage Baskets) are l 2 described below. In the near future, NNECO will be proposing additional changes to the Millstone Unit No.- 3 Technical

~

Specifications to prepare for the conversion to nominal 24-month' !

fuel cycles. Each of these submittals will contain evaluations that are independent and which stand alone.

I. surve111mnee neauirement 4.5.2.d.2. visual Inspection of containment an=p safety Assessment The four containment recirculation pumps take suction from a common containment sump which is enclosed by a protective screen assembly. Three stages of trash rejection are provided:

grating, coarse mesh and a fine mesh. The assembly is divided at the centerline by fine mesh screening so that failure of either half does not adversely affect the other half. The containment recirculation pumps from each subsystem take suction from each half of the sump. If half of the screen assembly should become clogged, water is still available to all suction points via the screening separating the two sections of the sump. There is also a1 inch grating at elevation -24 feet, 6 inches, which covers the sump and acts as a vortex breaker to prevent air entrainment in the pumps.

.. ~ .

d U. S. Nuclear Regulatory Commission '

B15296/ Attachment 4/Page 2 i July 14', 1995 i

Surveillance Requirement _ 4.5.2.d.2 verifies the operability of ]

the containment sump and subsystem inlets for the four '

recirculation pumps at least once per 18 months. The inspection of the sump ensures that the long term cooling will be available after a loss of cooling accident (LOCA). NNECO proposes to extend the frequency of Surveillance Requirement 4.5.2.d.2 from once per 18 months to at least once each refueling (i.e., nominal 24 months).

The proposed change to Surveillance Requirement 4.5.2.d.2 does not alter the intent or method by which the surveillances are conducted, does not involve any physical changes to the plant, does not alter the way any structure, system or component functions and does not modify the manner in which the plant is operated. As such, the proposed change to the frequency of Surveillance Requirement 4.5.2.d.2 will not degrade the ability of the containment sump and the subsystem suction inlets to perform their intended function. ,

A review of the past four inspections of the containment sump and i cubsystem suction inlets did not indicate any evidence of i struct.'aral distress or abnormal corrosion of the containment i subcomponants and did not indicate any significant debris that could restrict the subcyctem suction inlets. In all cases, the !

inspection acceptance criteria was met. A review of corrective maintenance records show that r;o corrective maintenance has been necessary or performed. It is also noted that no preventive maintenance is required on an 18 month basis. Based on the above evaluation, the proposed change is considered acceptable and safe.

A Probabilistic Risk Assessment (PRA) review concluded that there !

is negligible impact on risk, since most failures that are prevented by this surveillance (debris, etc.) are independent of the test interval.

significant nasards consideration NNECO has reviewed the proposed change in accordance with 10CFR50.92 and concluded that the change does not involve a significant hazards consideration (SHC). The basis for this conclusion is that the three criteria of 10CFR50.92(c) are not compromised. The proposed change does not involve an SHC because

.the change would not:

1. Involve a significant increase in the probability or consequences of an accident previously evaluated.

4 The proposed change to Surveillance Requirement 4.5.2.d.2 extends the frequency for the inspection of the containment

..- I U. S. Nuclear-Regulatory Commission B15296/ Attachment 4/Page 3 July-- 14, 1995 l sump. and subsystem inlets for the four . containment l

-recirculation pumps. The proposal would extend the frequency j from at least once per 18 months to at. least once each refueling interval (i.e., nominal 24 months).

The proposed change to Surveillance Requirement 4.5.2.d.2 does not alter the intent or method by which the surveillances are conducted. In addition, the acceptance criterion for each of the surveillances is unchanged. As such, the proposed change to the frequency of Surveillance i Requirement 4.5.2.d.2 will not degrade the ability of the ECCS subsystems to perform their function.

An evaluation of past surveillances, preventive maintenance records and the frequency and type of corrective maintenances j concluded that decreasing the surveillance _ frequency will l have little impact on safety.

Since the proposed . change only affects the surveillance frequency for safety systems that are used to mitigate !

accidents, the proposed change can not affect the probability of any previously analyzed accident. While the proposed change lengthens the interval between surveillances, the extensions have no significant impact on the availability'of these safety systems and consequently, there is no impact on the-consequences of any analyzed accidents.

2. Create the possibility of a new or different kind of accident from any accident previously evaluated.

The proposed change to . Surveillance Requirement 4.5.2.d.2 does not change the design or operation of any plant system.

Since the proposed change only' affects surveillance frequencies and does not alter the intent or method by which the surveillances are conducted, the proposed change can not create the possibility of a new or different kind of accident from any previously analyzed.

3. Involve a significant reduction in a margin of safety.

Changing the frequency of Surveillance Requirement 4.5.2.d.2 from at least once per 18 months to at least once each refueling interval does not change the basis for frequency and the intent or method of performing the surveillances is-unchanged. The evaluation of past surveillances, preventive maintenance records and the type and the frequency of corrective maintenance concluded that decreasing the surveillance frequency will have little impact on safety.

Since decreasing the surveillance frequency does not involve a significant increase in the consequences of a design basis

i

,.Y l U. S. Nucler.r Regulatory Commission B15296/ Attachment 4/Page 4 July 14, 1995 accident previously analyzed, there is no reduction in the margin of safety.

II. survalliance'Reauirements 4.5.2.e.1. 4.5.2.e.2. and 4.5.2.h Automatic Valve positions. Automatic start of the chavaina.

Safety Iniection and num p ps safety Assessment Surveillance Requirement 4.5.2.e.1 verifies the operability of each automatic valve in the ECCS flow path. Surveillance Requirement 4.5.2.e.2 verifies the operability of each charging pump, safety injection pump and residual heat removal (RHR) pump by verifying that each of the pumps start automatically upon receipt of a safety injection (SI) test signal. These surveillances are required to be performed at least once per 18 months, during shutdown. NNECO is proposing to extend the frequency of Surveillance Requirements 4.5.2.e.1, and 4.5.2.e.2 from at least once per 18 months to at least once each refueling interval (i.e., nominal 24 months). In addition, the phrase "during shutdown" in Surveillance Requirements 4.5.2.e and i

4.5.2.h is being deleted. Because the terms " Hot Shutdown" and

" Cold Shutdown" are defined in the Millstone Unit No. 3 Technical Specifications as operating modes or conditions, the added restriction to perform certain surveillances may be misinterpreted. The proposed deletion of term "during shutdown" is consistent 04.

with the recommendation of Generic Letter (GL) 91-In GL 91-04, the NRC has concluded that the technical specifications need not restrict surveillances as only being performed during shutdown. However, the NRC indicated that if the performance of a refueling interval surveillance during plant operation would adversely affect safety, the licensee should postpone the surveillance until the plant is shutdown for refueling or in a condition or mode consistent with safe conduct of that surveillance. NNECO agrees with the NRC in its conclusion. NNECO believes that the deletion of the words "during shutdown" has no safety impact as long as the surveillances are conducted in any mode or condition without impacting plant safety.

The proposed changes to surveillance Requirements 4.5.2.e.1, and 4.5.2.e.2 do not alter the intent or method by which the surveillances are conducted, do not involve any physical changes to the plant, do not alter the way any structure, system or

. component functions, and do not modify the manner in which the l l plant is operated. As such, the proposed changes to the frequency of Surveillance Requirements 4.5.2.e.1, and 4.5.2.e.2 ;

r will not degrade the ability of each automatic valve in the ECCS E flow path to actuate to its correct position on an SI signal and

1

.. j 1

U. S. Nuclear Regulatory Commission B15296/ Attachment 4/Page 5 July 14, 1995 the ability of each charging pump, SI pump and RHR pump to start automatically upon a receipt of an SI signal.

Equipment performance over the last four operating cycles was evaluated to determine the impact on extending the frequency of Surveillance Requirement 4.5.2.e.1 and 4.5.2.e.2. This evaluation included a review of the past surveillance results, preventive maintenance records, and the frequency and type of corrective maintenance. The components covered by these surveillances are shown on Table 1.

The review indicated that the automatic valves in the 'A' and 'B' trains actuated as required in response to the SI test signal in each case. In all cases, the charging pump and the charging pump cooling pumps, SI pumps and SI pump cooling pumps, and RHR pumps started automatically in response to the SI test signal. ,

A review of the preventive maintenance records for all the above pumps revealed that no mechanical preventive maintenance is required on an 18 month basis. For the above pumps, an oil change is performed on an 18 month basis but the manufacturer does not require oil changes unless:

a 011 discoloration occurs or Foreign particles appear in the oil.

The oil change could be performed with the plant on line if necessary or once every 24 months as preventive maintenance.

Hypot testing of the motors and cables is also scheduled every 18 U) months to coincide with the refueling outage preventive maintenance. Experience has shown a very low failure rate when tested in the past.

Corrective maintenance work performed on these pumps during the last four operating cycles involved minor gasket leaks and oil level adjustments. In all cases, repairs were able to be performed with no adverse impact on plant operation.

In addition to the 18 month surveillance which verifies the pumps start on receipt of an SI test signal, the pump differential pressure and vibration are monitored by the inservice testing program (Specification 4.0.5) on a quarterly basis. Also, Surveillance Requirement 4.5.2.b.2 verifies that each valve (manual, power-operated, or automatic) in the flow path is in its correct position at least once per 31 days. These surveillances l provide additional assurance that the ECCS subsystem components will be operable and will perform their integrated function. On -

the basis of the above evaluation, the proposed changes are acceptable and safe.

1

6 e

U. S. Nuclear Regulatory Commission '

B15296/ Attachment 4/Page 6 July 14, 1995 A PRA review was performed to assess the impact of the surveillance time interval extension on public health and safety.

That review concluded the change in risk to be minimal. The major reasons for that conclusion are 1) the quarterly tests that assures functionality, and 11) the operating experience (only one valve failed to change position during the last six tests).

sicrniflammt Manards consideration NNECO has reviewed the proposed changes in accordance with 10CFR50.92 and concluded that the changes do not involve an SHC.

The basis for this conclusion is that the three criteria of 10CFR50.92(c) are not compromised. The proposed changes do not involve an SHC because the changes would not:

1. Involve a significant increase in the probability or consequences of an accident previously evaluated.

The proposed changes to surveillance Requirements 4.5.2.e.1, and 4.5.2.e.2 extend the frequency for verifying that (1) each automatic valve in the ECCS flow path actuates to its correct position on an SI signal, and (2) each charging pump, SI pump and RHR pump starts automatically upon receipt of an SI signal. The proposal would extend the frequency from at least once per 18 months to at least once each refueling interval (i.e., nominal 24 months).

The proposed changes to Surveillance Requirements 4.5.2.e and

4. 5. 2.h delete the term "during shutdown." These proposed changes have no impact on the probability or consequences of an accident previously analyzed.

The proposed changes to surveillance Requirement .4.5.2.e.1, and 4.5.2.e.2 do not alter the intent or method by which the surveillances are conducted. I.n addition, the acceptance criterion for each of the surveillances are unchanged. As such, the proposed changes to the frequency of Surveillance Requirements 4.5.2.e.1, and 4.5.2.e.2 will. not degrade - the ability of the ECCS subsystem components to perform their function.

An evaluation of past surveillances, preventive maintenance records and the frequency and type of corrective maintenance concluded that decreasing the surveillance frequency will have little impact on safety.

Since the proposed changes only affect the surveillance frequency for safety systems that are used to mitigate -

accidents, the proposed changes can not affect the probability of any previously analyzed accident. While the

j ...

-U. S. Nuclear Regulatory Commission B15296/ Attachment'4/Page 7 July 14, 1995 ;

proposed changes lengthen the interval between survoillances, the extension has no significant impact on the availability ;

of these safety systems and consequently there is no impact on the consequences of any analyzed accidents. !

2. Create the. possibility of a new or different kind of accident from any accident previously evaluated.

The proposed changes to Surveillance Requirements 4.5.2.e.1, 4.5.2.e.2 and 4.5.2.e.3 do not change the design or operation of any plant system. Since the proposed changes only affect surveillance frequencies and do not alter the intent ~or method by which the surveillances are conducted, the proposed changes can not create the possibility.of a.new or different kind of accident from any previously analyzed.

3. Involve a significant reduction in a margin of safety.

Changing the frequency of Surveillance Requirements

-4.5.2.e.1, and 4.5.2.e.2 from at least once per 18 months'to at least once each refueling does not change the basis for i frequency and the intent or method of performing the )

surveillances is unchanged. The evaluation of past surveillances, preventive maintenance records and the type and the frequency of corrective maintenance concluded that decreasing the frequency will have little impact on safety.

Since decreasing the surveillance frequency does not involve a significant increase in the consequences of a design basis accident previously analyzed, there is no reduction in the ;

margin of safety.- I III. Surveillanea naauirement 4.5.2.a.2. EccB Throttia Valva Position Safety Assessment The emergency core cooling system (ECCS) was flow balanced by system testing during pre-operational testing at Millstone Unit No. 3. Surveillance Requirement 4.5.2.g.2 verifies the operability of certain ECCS throttle valves (a list is included under Surveillance Requirement 4.5.2.g.2) by checking the correct position of each electrical and/or mechanical position stop at least once per 18 months. NNECO proposes to extend the frequency of Surveillance Requirement 4.5.2.g.2 from once per 18 months to at least once each refueling interval (i.e., nominal 24 months).

The proposed change to Surveillance Requirement 4.5.2.g.2 does not alter ' the intent or method by which the surveillances are conducted, does not involve any physical changes to the plant, does not alter the way any structure, system or component 1

y

4 .

U. S. Nuclear Regulatory Commission B15296/ Attachment 4/Page'8 July 14, 1995 functions.and does not modify the manner in which the plant is operated. As such, the proposed change to the frequency of Surveillance Requirement 4.5.2.g.2 will not degrade the ability of the ECCS throttle valves to perform their function.

Equipment performance (i.e., valves included in Surveillance Requirement 4.5.2.g.2) over the last four operating cycles was evaluated to determine the impact on extending the frequency of Surveillance Requirement 4.5.2.g.2. This evaluation included a review of past surveillance results, preventive ' maintenance records and the frequency and type of corrective maintenance.

The review of surveillance results indicate that the valve positions were within acceptable tolerance for all surveillances performed, except in cases where the valves had maintenance performed. Valves were restored to their throttle position at the completion of maintenance activity.

Corrective maintenance performed on these valves was limited to packing adjustments and replacements. After each maintenance activity, the valve was restored to its required throttle position.

A review of preventive maintenance records revealed that no preventive maintenances are performed on an 18 month basis.

In addition to the 18 month surveillance which verifies correct throttle position of certain ECCS valves, Surveillance Requirement 4.5.2.g.1 requires that within four hours following completion of each valve stroking, operation or maintenance on the valve, the valve is required to be restored to its required throttle position. This additional surveillance provides additional assurance that the ECCS throttle valves will be operable and will perform their intended function. On the basis of the above evaluation, the proposed change is acceptable and safe. An independent PRA review of past operating experience concurred with this conclusion.

Significant Hazards consideration NNECO has reviewed the proposed change in accordance with 10CFR50.92 and concluded that the change does not involve an SHC.

The basis for this conclusion is that the three criteria of 10CFR50.92(c) are not compromised. The proposed change does not involve an SHC because the change would not:

1. Involve a significant increase in the probability or consequences of an accident previously evaluated.

The proposed change to Surveillance Requirement 4.5.2.g.2 extends the frequency for verifying the correct position of

i. .

e

.e .i

-,s U. S. Nuclear Regulatory Commission B15296/ Attachment 4/Page'9 July 14, 1995 certain ECCS throttle valves.- The proposal would extend the '

frequency from at least once per is months to at least once each refueling interval (i.e., nominal 24 months).

The proposed change to Surveillance Requirement 4.5.2.g.2 l does not alter the intent or method by which the surveillance !

is conducted. In addition, the acceptance criterion for the ;

surveillance is unchanged. As such the proposed change to i the frequency of Surveillance Requirement 4.5.2.g.2 will not ;

degrade the ability of the ECCS throttle valves to perform ;

their function. ,

An evaluation of past surveillances, preventive maintenance ,

records and the frequency and type of corrective maintenance concluded that decreasing the surveillance frequency will have little impact on safety.

Since the proposed change only affects the surveillance .

frequency for the ECCS throttle valves that are used to ~!

mitigate accidents, the proposed change can not affect the probability of any previously analyzed accident. While the proposed change lengthens the interval between surveillances, the extunsion has no significant impact on the availability of these ECCS throttle valves and consequently there is no-impact on the consequences of any analyzed accident.

2. Create the possibility of a new or different kind of accident from any accident previously evaluated.

The proposed change to Surveillance Requirement 4.5.2.g.2 does not change the design or operation of any plant system.

Since the proposed change only affects surveillance frequencies and does not alter the intent.or method by which the surveillances are conducted, the proposed change can not create the possibility of a new or different kind of accident from any previously analyzed.

i.

3. Involve a significant reduction in a margin of safety.

Changing the frequency of Surveillance Requirement 4.5.2.g.2 from at least once per 18 months to at least once each refueling interval (i.e., nominal 24 months) does not change the basis for frequency and the intent or method of performing the surveillances is unchanged. The evaluation of past surveillances, preventive maintenance records and the type and the frequency of corrective maintenance concluded that decreasing the frequency will have little impact on safety. Since decreasing the surveillance frequency does not involve a significant increase in the consequences of a

O O

U. S. Nuclear Regulatory Commission B15296/ Attachment 4/Page 10 July 14, 1995 design basis accident previously analyzed, there is no reduction in the margin of safety.

IV. surveillance Reauirements 4.5.2.d.1, RHR/RCS System Interlock. and 4.5.2.e.3 RWST Low RER Punn Ston Interlock channel calibration safety Assessment The residual heat removal (RHR) system isolation valves are normally closed and are only opened for residual heat removal after the reactor coolant system (RCS) pressure is reduced to approximately 390 psia. There are three valves (motor-operated valves) in series for each of the two RHR pump suction lines from the RCS hot legs. Two valves located close to the containment walls, one inside containment and one outside containment, are provided with interlocks. Each of the two valves is interlocked so that it cannot be opened unless the RCS pressure is below approximately 390 psia. The interlocks for each train are independent and diverse. If the valve remains open and the RCS pressure increases above 455 psia, an alarm will sound requiring operator action.

Surveillance Requirement 4.5.2.d.1 verifies automatic interlock action of the RHR system from the RCS by ensuring that, with a simulated or actual RCS pressure signal greater than or equal to 390 psia, the interlock prevents the valves from being opened.

This surveillance is performed at least once per 18 months.

NNECO proposes to extend the frequency of Surveillance Requirement 4.5.2.d.1 from once per 18 months to at least once each refueling interval (i.e., nominal 24 months).

The refueling water storage tank (RWST) low-low level setpoint stops the RHR pumps which is alarmed to alert the operator to realign the emergency core cooling system from injection to the recirculation mode following a design basis accident.

Surveillance Requirement 4.5.2.e.3 verifies that the RHR pumps stop automatically upon receipt of a low-low RWST level test signal once per 18 months. NNECO proposes to extend the frequency of Surveillance Requirement 4.5.2.e.3 from once per 18 months to at least once each refueling interval (i.e., nominal 24 months).

Surveillance Procedures SP 3442J01 and 3451B03 are used to perform the surveillance. A review of the past surveillance results indicate that these instruments were calibrated within the acceptance criteria and there were no indication of linear time dependent drift with regard to the circuit components.

4 i

U. S. Nuclear Regulatory Commission B15296/ Attachment 4/Page 11 July 14, 1995 A review of past preventive maintenance and corrective maintenance activities did not identify any significant activities that were required to correct component failures. A PRA review concluded that the proposed change is not risk significant.

On the basis of the above evaluations, there is a reasonable assurance that the frequency of Surveillance Requirements 4.5.2.d.1 and 4.5.2.e.3 can be extended from at least once per 18 months to once each refueling (i.e., nominal 24 months).

Significant Hazards Consideration NNECO has reviewed the proposed changes in accordance with 10CFR50.92 and has concluded that the changes do not involve a significant hazards considerations (SHC). This basis for this conclusion is that the three criteria of 10CFR50.92(c) are not compromised. The proposed changes do not involve a SHC because the changes would not:

1. Involve a significant increase in the probability or consequences of an accident previously evaluated.

The proposed changes to Surveillance Requirements 4.5.2.d.1 and 4.5.2.e.3 extend the frequency for demonstrating operability of the RHR/RCS system interlock and RWST low RHR pump stop interlock system by a performance of a channel calibration. The proposal would extend the frequency from at least once per 18 months to at least once each refueling interval (i.e., nominal 24 months).

The proposed changes do not alter the intent or method by which the surveillance is conducted. In addition, the acceptance criterion for the surveillance is unchanged. As such, the proposed changes will not degrade the ability of the RHR/RCS system interlock and RWST low RHR pump stop interlock to perform its intended function.

An evaluation of past surveillances, preventive maintenance records and the frequency of the type of corrective maintenances concluded that decreasing the surveillance frequency will have little impact on safety. Since the proposed changes only affect the surveillance frequency, the proposed changes can not affect the probability of any previously analyzed accident. While the proposed changes can lengthen the intervals between surveillances, the increase in intervals has been evaluated and it is concluded that there is no significant impact on the reliability or availability of the PORVs and consequently, there is no impact on the consequences of any analyzed accident.

^n j

,,- a

... 1 U. 5. Nuclear Regulatory. Commission B15296/ Attachment 4/Page 12 July 14,-1995

2. Create the possibility of a new' or different kind of accidents from any accident previously evaluated.

The proposed changes to Surveillance Requirements 4.5.2.d.1 and 4.5.2.e.3 do not modify the design'or operation of any plant system. The proposed changes do not alter the intent or. method by which the surveillance is conducted other than increasing the interval from 18 months to refueling interval (i.e., nominal 24 months). The proposed changes do not introduce a new failure mode. Therefore, the proposed changes do not create the possibility of a new or different kind of accident from any previously analyzed.

3. Involve a significant reduction in a margin of safety. ,

Changing the frequency of Surveillance Requirements 4.5.2.d.1 and 4.5.2.e.3 from at least once per 18 months to once each refueling interval (i.e., nominal 24 months) does not change the basis for frequency. The proposed changes do not alter the intent or method by which the surveillance is conducted, do not involve any physical changes to the plant, do not alter the way any structure, system or component functions and do not modify the manner in which the plant is operated.

Further, the previous history of the RHR/RCS system interlock and RWST low RHR pump stop interlock system provides assurances that the change'will not affect the reliability of these valves. Thus tha proposed changes have no impact on the margin of safety.

I ____ _ _ _ _ _ _ _ _ _ _ _

J l < p.

oe-I, '

L U. S. Nuclear Regulatory Commission ,

B15296/ Attachment 4/Page 13

. July 14, 1995 Table 1 !

Equipment Impacted by Technical specification- i Requirement 4.5.2.e.1 a-EQUIPMENT DESCRIPTION 3CCE*AOV26A Charging Pump Coolers Outlet Crossovers 3CCE*AOV30A Charging Pump Cooling Pump Discharge Crossover ;

Connection e 3CHS*LCV112B Volume Control Tank Outlet Isolation 3CHS*LCV112D RWST to Charging Pump Suction 3CHS*MV8105 Charging Pump to Reactor Coolant System l 3CHS*MV8110 Charging Pump Mini Flow Isolation 3CHS*MV8112 RCP Seal Water Isolation 3CHS*MV8511A Charging Pump Mini Flow Isolation 3CHS*SV8160 Letdown Isolation 1 3RSS*MOV20A Containment Recirculation Water Spray 3RSS*MOV20C Containment Recirculation Water Spray 3RSS*MOV23A Containment Recirculation Pump Suction 3RSS*MOV23C Containment Recirculation Pump Suction 3SIL*CV8825 RHR Hot Leg Injection Test Line 3SIL*CV8968 Accumulator Nitrogen Isolation i l

3SIL*CV8890A RHR Pump Cold Leg Test'Line 3SIL*CV8890B RHR Pump Cold Leg Test Line 3SIH*CV8823 SIH Cold Leg Test Line 3SIH*CV8824 SIH Hot Leg Test Line-3SIH*CV8843 Charging Pump Test Line Isolation 3SIH*CV8871 Accumulator Test Line Header 3SIH*CV8881 SIH Hot Leg Test Line 3SIH*MV8801A Charging Pumps to Reactor Coolant System Cold Legs 4

v p =---ws >r- . ., , , - _ . - . - , , . , - . , .

4

+

9 i

U. S. Nuclear Regulatory Commission B15296/ Attachment 4/Page 14 July 14, 1995 Table 1 (cont.)

! Equipment Impacted by Technical Specification Requirement 4.5.2.e.1 EQUIPMENT DESCRIPTION

^

3CCE*AOV26B Charging Pump Coolers Outlet Crossovers l

3CCE*AOV30B Charging Pump Cooling Pump Discharge Crossover Connection 3CHS*CV8152 Letdown Isolation 3CHS*LCV112C Volume Control Tank Outlet Isolation 3CHS*LCV112E RWST to Charging Pump Suction j 3CHS*MV8100 RCP Seal Water Isolation Pump Suction 3CHS*MV8106 Charging Pump to Reactor Coolant System 3CHS*MV811A Charging Pump A Recirculation 3CHS*MV811B Charging Pump B Recirculation 3CHS*MV811C Charging Pump C Recirculation 3CHS*MV8511B Charging Pump Mini Flow Isolation 3RSS*MOV20B Containment Recirculation Water Spray 3RSS*MOV20D Containment Recirculation Water Spray 3RSS*MOV23B Containment Recirculation Pump Suction 3RSS*MOV23D Containment Recirculation Pump Suction 3SIL*CV8880 Accumulator Nitrogen Isolation )

3SIH*CV8888 Accumulator Fill Line 3SIH*CV8964 Accumulator Test Line Header 3SIH*MV8801B Charging Pumps to Reactor Coolant System Cold Legs L

l

.1

.i

.$~

f' l

' U. . S . Nuclear Regulatory Commission B15296/ Attachment 4/Page 15 ,

' July 14, 1995 !

Table 1 (cont.)

Equipment Impacted by Technical specification Requirement 4.5.2.e.2

~

EQUIPMENT DE8CRIPTION '

3RHS*P1A RHR Pump 'A' 3SIH*P1A Safety Injection Pump 'A' 3CCI*P1A Safety Injection Pump 'A' Cooling Pump 3CHS*P1A/C Charging Pump 'A'/'C' 3CCE*P1A Charging Pump Cooling Pump 'A' l l

EQUIPMENT DESCRIPTION 3RHS*P1B RHR Pump 'B' ,

i 3SIH*P1B Safety Injection Pump 'B' 3CCI*P1B Safety Injection Pump 'B' Cooling Pump 3CHS*P1B/C Charging Pump 'B'/'C' l 3CCE*P1B Charging Pump Cooling Pump 'B' l 1

c b'

o U. S. Nuclear Regulatory Commission B15296/ Attachment 4/Page 16 July 14, 1995

v. pH Trisodium Phosphate storage Baska.ts . Burveillance Reauirement 4.5.5 safety Assessment Surveillance Requirement 4.5.5 requires that the trisodium phosphate (TSP) baskets shall be demonstrated operable at least once each REFUELING INTERVAL by verifying that a minimum total of 974 cubic feet of TSP is contained in the TSP storage baskets. Presently, a refueling interval is defined as once per 18 months. NNECO is proposing to extend the frequency of Surveillance Requirement 4.5.5 from at least once per 18 months to at least once per 24 months (i.e., at least once each refueling interval). No word changes are required to Surveillance Requirement 4.5.5.

Technical Specification Surveillance Requirement 4.5.5 as issued in License Amendment No. 115 on May 26, 1995, reflects the surveillance requirement associated with the new TSP baskets installed in Millstone Unit No. 3 for containment sump pH control in the event of a loss of coolant accident.

The surveillance requirement requires that a visual of the volume of the TSP in the baskets will be performed once each refueling interval. This requirement already considered the fact that Millstone Unit N). 3 is in the process of extending the refueling interval from 18 months to 24 months. As stated in the documentation for the request for the amendment, the TSP powder has been determined to be chemically stable and its neutralization capabilities do not change with time. The only reason for the required surveillance is to assure that some of the TSP powder has not been washed out due to local leaking valves or components.

The access to the TSP basket is feasible (from ALARA aspect) only during outages (e.g. refueling outages). Because of the margin of the TSP installed, this frequency of once every refueling interval is acceptable.

Further considerations which support this frequency are:

a Baskets are raised 6" above the floor to protect the TSP from any remote leak finding its way to the basket area.

Baskets are equipped with stainless steel covers to protect them from direct leaks from overhead, e

E.. 1 L + j g' l U. S. Nuclear Regulatory Commission B15296/ Attachment 4/Page 17 July 14, 1995 Baskets are located in the containment lower level away from equipment drains and major piping.

Experience from Millstone Unit No. 2 and from the Haddam Neck Plant surveillance records of their TSP baskets has not shown a need for TSP addition due to washout.

There are 12 baskets in Unit No. 3 containment. A washout is not likely to affect more than one basket, or 8-1/3 percent of the total. The 974 cubic feet of TSP required, already include a conservative margin (based on 54 lb per cub. ft.) to compensate for such an event. A further margin of about 14 percent was actually implemented as proven by the fact that over 60,000 lbs of TSP were installed, when only 974 x 54 = 52,596 lbs were required.

Significant Hazards Consideration NNECO has reviewed the proposed change in accordance with 10CFR50.92 and has concluded that the change does not involve a significant hazards consideration (SHC). The basis for this conclusion is that the three criteria of 10CFR50.92(c) are not compromised. The proposed change does not involve an SHC because the change would not:

1. Involve a significant increase in the probability or consequences of an accident previously evaluated.

The proposed change extends the frequency of Surveillance Requirement 4.5.5 from at least once per 18 months to at least once per 24 months (i.e., at least once each refueling interval). The surveillance requirement specifies that a visual verification of the volume of the trisodium phosphate in the baskets will be performed.

The access to the TSP baskets is feasible only during outages (e.g., the refueling outage). It has been determined that the TSP powder is chemically stable and its neutralization capabilities do not change with time.

The only purpose of this surveillance is to assure that some of the TSP powder has not been washed out due to local leaking valves or components. It is noted that the baskets are equipped with stainless steel covers to protect them from any direct leak from overhead. In addition, the baskets are raised 6" above the floor to protect TSP from any leak finding its way to the basket

p e

t 3-0 U. S. Nuclear Regulatory Commission B15296/ Attachment 4/Page 18 July 14, 1995 l

area. Therefore, it is concluded that there is no impact on the availability of the TSP powder during the plant operation and, consequently, there is no impact on the consequences of an analyzed accident. In addition, the TSP baskets are passive components and a failure of the TSP basket does not initiate an accident. Therefore, an extension to the surveillance frequency will not have any adverse impact on the probability of an accident previously evaluated.

2. Create the possibility of a new or different kind of accident from any accident previously evaluated.

The proposed change to Surveillance Requirement 4.5.5 does not modify the design or operation of any plant system. The proposed change does not alter the intent or-method by which the surveillance is conducted other than l increasing the interval from 18 months to 24 months I (nominal). The proposed change does not introduce a new failure mode. Therefore, the proposed change, does not create the possibility of a new or different kind of l accident from any previously analyzed.

3. Involve a significant reduction in a margin of safety. l The proposed change to Surveillance Requirement 4.5.5 l does not change the basis for frequency. The TSP powder I has been determined to be chemically stable and its i neutralization capabilities do not change with time. The only reason for the required surveillance is to assure that some of the TSP powder has not been washed out due to local leaking valves or components. Based on the location of the baskets and the protection to the TSP baskets provided, it is unlikely that the TSP powder will be washed away due to a leak from components. However, it is estimated that any kind of washout will impact no l more than one basket or 8-1/3 percent of the total quantity. An adequate margin is included in the installed TSP baskets to compensate for such an event.

Consequently, there is no adverse impact on the consequences of any analyzed accident. Thus, the proposed change has no impact on the margin of safety.

ML20086K317

Text

Background

Navigation menu

Search