ML20101K746

COL Docs - FW: Vogtle 3&4 LAR Pre-Submittal Meeting Request

ML20101K746
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Site:	Vogtle
Issue date:	04/10/2020
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From: Rankin, Jennivine Sent: Friday, April 10, 2020 8:55 AM To: Vogtle PEmails

Subject:

FW: RE: Vogtle 3&4 LAR Pre-Submittal Meeting Request Attachments: LAR-20-004_PSM_Draft_NRC.pdf SNC draft LAR 20-004 to support public meeting on 4/23.

From: Henderson, Ryan Donald <RDHENDER@SOUTHERNCO.COM>

Sent: Thursday, April 09, 2020 3:28 PM To: Rankin, Jennivine <Jennivine.Rankin@nrc.gov>

Cc: Arafeh, Yasmeen N. <YNARAFEH@southernco.com>; Humphrey, Mark Phillips

<MPHUMPHR@southernco.com>; Santos, Cayetano <Cayetano.Santos@nrc.gov>

Subject:

[External_Sender] RE: Vogtle 3&4 LAR Pre-Submittal Meeting Request

Jennie, See attached for the draft LAR in preparation for the Pre-Submittal Meeting on 4/23. Assuming the comments from the staff are manageable, we intend to submit the LAR by 4/30.

Thanks, Ryan Henderson Licensing Office: 205-992-6426 Cell: 205-613-0342

Hearing Identifier: Vogtle_COL_Docs_Public Email Number: 555 Mail Envelope Properties (MN2PR09MB4891C8119FC500466AFC50BD98DE0)

Subject:

FW: RE: Vogtle 3&4 LAR Pre-Submittal Meeting Request Sent Date: 4/10/2020 8:54:33 AM Received Date: 4/10/2020 8:54:39 AM From: Rankin, Jennivine Created By: Jennivine.Rankin@nrc.gov Recipients:

"Vogtle PEmails" <Vogtle.PEmails@nrc.gov>

Tracking Status: None Post Office: MN2PR09MB4891.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 735 4/10/2020 8:54:39 AM LAR-20-004_PSM_Draft_NRC.pdf 910442 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Southern Nuclear Operating Company ND-20-XXXX T

Enclosure 1 RAF Vogtle Electric Generating Core rating Plant (VEGP) e Makeup Tank Boron Conce (LAR-20-004)

(LAR R-20 20--004 0 )

P) Units 3 and 4 Amendment::

Request for License Amendment Requirements Concentration Re D

(This Enclosure consists of 17 pages, including this cover page)

ND-20-XXXX Core Makeup Tank Boron Concentration Requirements (LAR-20-004)

Table of Contents

1.

SUMMARY

DESCRIPTION

2. DETAILED DESCRIPTION

3. TECHNICAL EVALUATION

4. REGULATORY EVALUATION 4.1 4.2 4.3 4.4 T

Applicable Regulatory Requirements/Criteria Precedent Significant Hazards Consideration Determination Conclusions etermination termin R

5.

6.

AF ENVIRONMENTAL CONSIDERATIONS REFRENCES TIONS D

Page 2 of 17

ND-20-XXXX Core Makeup Tank Boron Concentration Requirements (LAR-20-004)

Pursuant to 10 CFR 52.98(c) and in accordance with 10 CFR 50.90, Southern Nuclear Operating Company (SNC, or the Licensee) hereby requests an amendment to Combined License Lice (COL)

Nos. NPF-91 and NPF-92 for Vogtle Electric Generating Plant (VEGP) Units 3 and respectively.

d 4, res respe

1.

SUMMARY

DESCRIPTION The requested amendment proposes changes to the upper limit of the Core Ma Makeup Tank (CMT) boron concentration Technical Specification (TS) Surveillance lance Requirement ance Requ R rement (SR), the irement mass of trisodium phosphate (TSP) required by TS Limiting Condition Condit for Operation eration (LCO) and associated SR, and the frequency of performance of the CMT boron concentration TS SR.

The requested amendment proposes changes to the Appendix A). This enclosure requests approval implement the changes.

The licensing basis documents in the form of departures from the plant-specific Design Control incorporated into the UFSAR), and involves ntrol Document (DCD) Tier 2 information (as es changes to the plant-specific am pla -specific TS (C plant proval off the license amendment (COL necessary necess to R

2. DETAILED DESCRIPTION AF As described in the UFSAR, the function to provide emergency a safety-related system and assive Core Cooling System (PXS) performs he Passive nd consists of two refueling water storage tank (IRWST), the tw CMTs, adjustment baskets, and associated piping, valv equipment.

The CMTs provide involving loss two CMTs line Ts loops.. During boration ine break.

CMT rovide Reactor Coolant System (RCS)

Ts, two accumulators, (RC mak oss of coolant when the normal makeup sy accumulat accumul pe p the primary ooling following postulated design basis events. PXS is cy core cooling the in-containment removal heat exchanger, pH he passive residual heat re instrumentation, and other related valves, instrum makeup and boration during events not system is unavailable or insufficient. The elevation slightly above the reactor coolant s are located inside the containment at an e ing normal operation, the CMTs are completely full of cold, borated water. The ability of these tanks provides adequate ration capability ade core shutdown margin following a steam The CMTs are connected to the RCS tthrough a discharge injection line and an inlet pressure balance line ne connected to a cocold le leg. The discharge line is blocked by two normally closed, parallel air-operated valves that open on a loss of air pressure or electrical power, or perated isolation val valv on control signal al actuation.

actu D continuously lanc line from the cold leg is normally open to maintain the CMTs at RCS The pressure balance pressure, which prevents preven water hammer upon initiation of CMT injection.

prev The cold leg pressure pres ntinuously upward this line ne will b up balance line is connected to the top of the cold leg and is routed to the high point near the CMT inlet. The normal water temperature in be hotter than the discharge line.

The outlet line from the bottom of each CMT provides an injection path to one of the two direct vessel injection lines, which are connected to the reactor vessel downcomer annulus. Upon receipt of a safeguards actuation signal, the two parallel valves in each discharge line open to align the associated CMT to the RCS.

Page 3 of 17

ND-20-XXXX Core Makeup Tank Boron Concentration Requirements (LAR-20-004)

There are two operating processes for the CMTs, steam-compensated injection and water recirculation. During steam-compensated injection, steam is supplied to the CMTs Ts to t displace the water that is injected into the RCS. This steam is provided to the CMTs through tthe cold leg pressure balance line. The cold leg line only has steam flow if the cold legs are voided.

ar voide During water recirculation, hot water from the cold leg enters the CMTs, Ts, and the cold water in the tank is discharged to the RCS. This results in RCS boration and a net increase increa in RCS mass.

The operating process for the CMTs depends on conditions th RCS, primarilyy voiding ns in the voidin in the cold leg. When the cold leg is full of water, the cold leg eg pressure balance line remains fu full of water and the injection occurs via water recirculation. culation. If RCS inventory decreases sufficiently to cause cold leg voiding, then steam flows ows through the cold leg balance lines to the CMTs.

Also, the CMTs provide passive safety injection tion duringng loss of coolant relatively coolan accidents at a rela high flow for a longer duration than the accumulators.

ccumulators. During a los accident, they loss of coolant accid provide injection rates commensurate with the severity off the loss of coolant accident. accid For a larger loss of coolant accident, ent, and after the automatic depressurization dent, depres depressuriza system has been actuated, the cold legs are e expected ected to be voided. In this situation, ththe CMTs operate at their maximum injection rate eam entering the CMTs through the e with steam t cold leg pressure balance lines.

For smaller loss of coolant oolant initially operate in the water recirculation mode olant accidents the CMTs initia since the cold legss are water filled. During fille Dur ing water recirculation, g this w recircula the CMTs remain full, but the cold, borated d water is purged with hot, less bo borated cold leg water. The water recirculation provides RCS S makeup and also effectively boratesbora the RCS. As the accident progresses, when the cold legsleg void, the e CMTs switch to the stea ssteam displacement mode which provides higher flow low ow rates rates.

Connections nnections are provided for remotely adjusting adjustin the boron concentration of the borated water in each CMT during normal nor operation, as required. Makeup water for the CMT is plant operati provided by the Chemical and Volume C Control System (CVS). Samples from the CMTs are taken periodically to check bo concentration.

boron conc Control of the containment sump water post-accident is achieved through the use e pH in the containm of pH adjustment baskets ent ba baske ts containing con granulated TSP. The baskets are located below the minimum post-accident ccide floodup floo level, and chemical addition is initiated passively when the water reaches the baskets.

basket The baskets are placed at least a foot above the floor to reduce ba the chance chance thatt wate sspills in containment will dissolve the TSP.

water The TSP is designed design to maintain the pH of the containment sump water in a range from 7.0 to 9.5. The chemistry che reduces radiolytic formation of elemental iodine in the containment sump,p, consequently conse reducing the aqueous production of organic iodine, and ultimately reducingg the t airborne iodine in containment and offsite doses.

The chemical addition also helps to reduce the potential for stress corrosion cracking of stainless steel components in a post floodup condition, where chlorides can leach out of the Page 4 of 17

ND-20-XXXX Enclosure 1 Core Makeup Tank Boron Concentration Requirements (LAR-20-004) containment concrete and potentially affect these components during a long-term floodup event.

LCO 3.6.8, pH Adjustment, requires the pH adjustment baskets contain 25,920 lbs of TSP.

SRs exist to verify this and to verify that a sample of the TSP in the pH H adjustment adjust baskets bask provides adequate pH adjustment of the post-accident water.

Two sample lines, one in the upper head and the other in the lower ower head, are provided pro for sampling the solution in the core makeup tank. A fill connection on is provided for core makeup m

tank make up water from the chemical and volume control system.

system verify the boron concentration in each CMT T

Prior to the collection of liquid samples either in the laboratory aboratory or in the grab sampling unit, the lines are purged with source liquid to provide representative samples. The purging flow returns to the effluent holdup tank of the liquid radwaste LCO 3.5.2, CMTs - Operating, requires both dwaste system.

h CMTs to be operable. One T is 3400 ppm and 37 O of the SRs exists ex 3700 ppm. LCO 3.5.3, 3.5. CMTs to D

- Shutdown, Reactor Coolant System (RCS) Intact, requiresuires one operable, with on CMT to be ope the same SR applicable to the required red CM CMT. The SR Frequency uency is 7 days.

Because the CMT is in open communication unication with the RCS ommunication R via the balan line, whenever the e balance surveillance is performed, thee volumee removed is replaced by water via the balance line. The RCS water is typically at a lower boron concentration; therefore, eac each ssample dilutes the CMT.

R Depending on the starting tartin artingg boron concentration, there is the ppossibility that this sampling activity could cause e the CMT boron concentration to fall to a point po which would require borated makeup. Borated d makeup at power is not desirable desirab because it forces the displaced water back into the RCS via the balance line. This causes additional additiona thermal transients on the balance a

line and also causes the potential for a reactivity reactiv excursion in the reactor if the boron AF concentration ation of the RCS is affected.

ration The e proposed d solution to mitigate these these issues is to raise the upper boron concentration limit permitted for the e CMT, e extend the frequency frequen of the CMT boron concentration surveillance, and to increase the mass of TSP required for the pH adjustment baskets.

Licensing Basis Change Descriptions:

Description Descr COL Appendix dix A, Technical Specifications S Changes x SR 3.5.2.4 4 maximum maximu boron concentration is revised from 3700 ppm to 4500 ppm x SR 3.5.2.4 frequency is revised from 7 days to 31 days 5.2.4 fr fre x LCO 3.6 3.6.8 and SR 3.6.8.1 required TSP is revised from 25,920 lbs to 26,460 lbs UFSAR AR Changes C

x UFSAR Subsection 6.3.2.2.4 required TSP is revised from at least 25,920 pounds to at least 26,460 pounds Page 5 of 17

ND-20-XXXX Core Makeup Tank Boron Concentration Requirements (LAR-20-004) x UFSAR Subsection 9.3.6.2.6 upper boron concentration of the CVS ability for borated makeup is revised to reflect that the 4375 ppm value is a nominal value Conforming changes to the Technical Specification Bases are identified for the Tec Technical Specifications changes. The changes will be made under the Technical al Speci Bases Specification Bas Control Program upon approval of the amendment and markups are provided for fo information only with this application.

3. TECHNICAL EVALUATION concentration to 4500 ppm resulting in the maximum T

Calculations were performed to provide validation that raising concentration of 3050 ppm is acceptable with respect sing the upper limit of the CMT boro mum amount a of post-accident concentration. The pH adjustment calculations were revised to use a more conserv maximum CMT water volume, which results in the maximum post-volume being revised from 867,308 gallons to 867,830 post-accident post-accid boron post-accident boron ect to long term containment pH and boron conservative accident containment w 30 gallons. The calculations resulted ativ water resulte in a R

change to the minimum measured TSP P volume from 480 ft3 to 490 ft3 to provid provide proper buffering of post-accident water.

The containment flood-up waterr sources and the available TSP have h been be analyzed to calculate a post-loss of coolant nt accident dent (LOCA) pH value. The goal of tthe calculation is to confirm that the pH is above 7.0 within n 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of an event. The results of o the calculation yield AF a minimum pH (utilizing the he minimum required TSP) of 7.23 when CMT C boron concentration is 4500 ppm, which corresponds ntainment flood-up rresponds to a containment flood-up boron concentration c of 3050 ppm.

Post-accident boron on concentration concentration calculations confirm two things: that there is adequate shutdown margin gin and that the maximum boron concentration concentr for the Reactor Vessel, the Containment,, and the th IRWST T does not cause boron bo to come c out of solution. Boron does not come out of solution solution due to high concentrations (i.e.

(i.e will w not go above the solubility limit). The increase e in maximum CMT boron concentration from fro 3700 ppm to 4500 ppm decreases the amount unt of margin with respect to solubility limits.

lim The reduction in margin is a minimal percentage.

ercentage. The margin to the solubility limit (35,000 ppm) for containment in the evaluation off maximum reactor vessel vess boron concentration concentra went from 29,387 ppm to 29,339 ppm and for the evaluation of maximum IRWST concentration con it went from 26,043 ppm to 26,007 ppm.

maximum CMT boron concentration with this magnitude has Therefore, the increase in the maxim overall margin to the solubility limit due to the significant margin little effect on the minimum ove which exists.

The equipment qualification qualificatio qua program previously evaluated 4375 ppm for the CVS and D equipment that could be subjected to the 4375 ppm of the CVS (including the CMTs). An e

increase to 4500 ppm does not significantly impact the conclusions of the existing analyses.

The increase in concentration decrease (making subjected co represents a 0.01 weight percent increase, and a 0.01 pH (makin the pH more acidic). These differences are negligible for the materials jected to the th increase in boron concentration.

The non-LOCA safety analyses typically model minimum CMT boron concentration for applications considering minimum safeguards and maximum CMT boron concentration for applications considering maximum safeguards. Since the time frame of interest for applications considering maximum safeguards is after a reactor trip, these analyses are not Page 6 of 17

ND-20-XXXX Core Makeup Tank Boron Concentration Requirements (LAR-20-004) sensitive to increases in the maximum CMT boron concentration. For cases where nominal safeguards are modeled, the increase in the CMT boron concentration would be e a benefit or have no impact. Therefore, the proposed change is acceptable with respect to non-LOCA o the non n

safety analyses.

COL Appendix A, Technical Specification 3.5.2 is proposed to be revised tot identify the maximum CMT boron concentration of 4500 ppm. The maximum boron oron concentration concentrat allowed within each CMT at any time shall be 4500 ppm to prevent overboration.

boration boration.

The boron concentration inside the CMTs is required to be maintained to support sa safety are periodically sampled based on the Technical T

analysis initial conditions. To confirm that the CMTs have sampling will identify the reduced boron concentration.

Due to the arrangement of the CMTs (see ca entration.

ation.

e UFSAR Figure e adequate boron concentration, the Requirements. Leakage from the CMT can lead to RCS water (at a lower boron concentration) entering the CMT and reducing the total available 6.3-1 ure 6.3 6.3--1 S they call Specification 3.5.2 Surveillance e boron in the CMT. If lleakage is occurring le occurring, 1),, the act of sampling Sheet 1) s RAF the CMTs also creates in-leakage from the RCS to the ta concentration. To minimize the effect between sampling is proposed. This Containment Refueling Water concentration in the CMT days.

concentration concentration boron).

500 ming into eakage. At leakage.

his ct of sampling er Storage acceptable as it can be demonstrated sam e Tank on CMT boron freque Tan (IRWST).

MT can continue to meet the minimum 340 Boron dilution predictions have int the CMT A a leakage leakage rate have been performed to evaluate n will reach 3400 ppm for different le T when the leak exists is pure rat of 0.125 gpm, the p

tank and reduces the boron oron concentration, concentration a longer time co s proposed change is to reduce the freque to 31 days which is consistentt with the sampling frequency of the frequency from 7 days he Accumulators Accu Accum and the In-WST). This change in sampling frequency is d that at low, undetectable leleakage rates, the boron 3400 ppm requirement for 31 evaluat the time the CMT average boron rates with an initial nominal CMT boron leak rat tion of approximately 4375 ppm and the cconservative assumption that the RCS water coming oming water (i.e., RCS water diluted to 0 ppm n). Thiss is conservative because a realistic RCS boron concentration is approximately dilution of the CMT boron concentration due to in-00 ppm and would therefore result in less dil th CMT average boron concentration remains at or above 3400 ppm for approapproximately 23 ddays. At lower leakage rates, such as 0.062 gpm, the CMT average boron concentration concentr remains at or above 3400 ppm for approximately 46 days.

rem At a leakage e rate of approximately approximate 0.1 0 gpm, the CMT average boron concentration will remain at or above 3400 days.

400 ppm for 29 day reducing sample frequency is that there are other indicators that can One justification for reduci D identify RCS leakage id temperature temperature kage into the CMT. An additional method to detect in-leakage from the RCS to the CMTs is to monitor Th mo mon perature elements e

the CMT temperature at the top of the tank since any leakage into the CMT results in water being pulled into the top of the tank through the normally open balance alance line. There are two non-safety-related (Safety Class E) thermowell mounted at the top of each CMT near the inlet nozzle which will alarm if the rature exceeds the setpoint of 107.5°F (this setpoint plus uncertainty is the 120°F CMT top high temperature alarm which has indication in the Main Control Room used for SR 3.5.2.1). There are CMT leakage levels that are detectable, as demonstrated by the time period it takes for the high temperature alarm to be reached from the steady state CMT temperature due to in-leakage, and therefore can indicate a potential reduction in the CMT Page 7 of 17

ND-20-XXXX Core Makeup Tank Boron Concentration Requirements (LAR-20-004) boron concentration before the surveillance frequency of 31 days if these higher leakage rates are occurring.

An analysis has been performed to evaluate small in-flow which would be indicative leakage dicative of lea from within the CMT. A range of leakage rates were evaluated to determine ine a detectable de level le of leakage by the rate of the change in CMT temperature. A Computationaltational tati onal Fl Fluid Dynamics (CFD) model, originally developed to evaluate flow out of the CMT T inlet when makeup m was added was modified to evaluate a small leak causing an in-flow w of water into the C CMT from the balance line. A leakage rate of 0.125 gpm was analyzed to demonstrate how rapid rapidly the temperature of the tank increases to the alarm setpoint at the CMT temperature elements at T

the top of the tank. These sensors are located on either side approximately 20 inches over the center line of the tank of 0.125 gpm, this analysis indicates the temperature within approximately 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />. For a leakage rate s of the inlet nozzle nk and 5 inches down. At a leakage zzle and ure increase from 100°F to 107.5°F occurs e of 0.25 gpm, a tempe 100°F to 120°F occurs within approximately 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.rs.

temperature increase from an e rate R

In order to address uncertainties in the CFD FD modeling, several co conservatisms were a applied to the CFD results as transient time multipliers.

tipliers. These applied conservatisms cons increase increa the time it takes the in-leakage to increase the CMT temperature.

temperature. The expected exp CMT temperature change will likely be greater than n the temperature change from 100°F100° to 1107.5°F that was modelled; however, this has beeneen addressed applie to the CFD results.

dressed by the conservatisms applied The CMT temperatures used modeling sed in the modelin mod g is representative of Mode M 1, steady state AF conditions; however, in Modes 2 and nd 3 the CMT temperature will experience similar temperature increase due to in-leakage. e. During Modes 4 and 5, 5 the lower pressure of the RCS will limit the potential otential for leakage.

le Based on the CFD modeling with additional conse conservatisms, it is predicted that at leakage rates conservatisms as low as approximately proximately 0.1 gpm, the alarm response respon to the top CMT temperature would occur within 20 days, and therefore the CMT top temperat temperature would detect leakages of this flow rate temperatur and higher er within a surveillance frequency of 31 da gher days. At a leakage rate of approximately 0.1 gpm,, and performing erforming a boron dilution analysis sstarting at a CMT boron concentration of 4375 ppm pm and RCS concentration of 0 ppm, the CMTC remains above 3400 ppm for approximately th CMT temperature 28 days and therefore the temperatu alarm would indicate the leakage in advance of the CMT concentration d dropping below belo 3400 ppm. At higher leakage rates, the high temperature alarm will be rea reached mmuch sooner. For example, at a leakage rate of 0.2 gpm the leakage would be indicated byb 6 days and per the boron dilution analysis, the CMT boron concentration reaches 3400 ppm at approximately 14 days. At a leakage rate of 0.125 gpm, the leakage would indicated by approximately 14 days and, the CMT boron concentration uld be indicate D reaches 3400 ppm Byy comparison o indicated pm at between the time th redu approximately 23 days. These cases demonstrate there is margin a app that the CMT high temperature indicates leakage and the CMT boron concentration is reduced reduc to 3400 ppm.

of the calculated allowable leakage time from the boron dilution analysis cases and the time ccalculated by the CFD model with conservatisms to detect the CMT leakage as ed by reaching the CMT top temperature alarm, CMT sampling could be conducted at a frequency of 42 days and the CMT boron concentration would remain at or above 3400 ppm.

Since the sampled boron concentration is expected to drop over the fuel cycle, either due to sampling itself or due to very small leaks in the CMT, the starting concentration may not Page 8 of 17

ND-20-XXXX Core Makeup Tank Boron Concentration Requirements (LAR-20-004) always be as high as the 4375 ppm initial concentration used in the boron dilution analysis cases. Based on the predictions for identifiable leakage, the starting CMT concentration entra could be as low as 4184 ppm boron concentration, conservatively assuming 0 ppm RC RCS boron concentration in-leakage, and still ensure that unacceptable leakage is identified entified prior to t the CMT violating the 3400 ppm boron concentration limit with a 31 day sampling mpling ffrequency.

Therefore, the CMT top high temperature alarm can indicate to the e operators operators that there may be in-leakage and to initiate by procedure steps to identify if the e CMT boron concentration he conce remains within the required limits. If the temperature or boron concentration is o outside acceptable limits, TS 3.5.2 Required Action B.1 or C.1 would be performed to restore the high temperature alarm.

T temperature and boron concentration in the affected CMT(s).

equired MT(s).

Therefore, a sampling frequency of 31 days will adequately equately demonstrate that the CMT boron concentration has been maintained within the required quired limits. Leakage at could a a rate which coul lead to a boron concentration less than 3400 ppm within 31 days will be indicated by the CMT C

RAF COL Appendix A, Technical Specification the boron concentration is adequate such as in-leakage considering (2.5 weight present) nominal value cation 3.5.2, is proposed surveillance of the CMT boron concentration ent) by taking suction from bothb alue and not intended to be the normal ope The total containment boron concentration is d concentration ncentration provided by various systems a the mass of the water. ThThe TSP concentration concentrat oposed to revise the fre entration to 31 days. The e to identify changes which could occur ate g the provisions for monitoring temperature increased temperature, which would be e indicative of in-leakage.

UFSAR Subsection 9.3.6.2.6 states that borated makeup m

in-leakage.

in-can be frequency of e 31 day verification frequency of o from fr mechanisms temperatur of the inlet line and top of the CMT. Additionally,, the top of the CMT has control room indication indic and an alarm on b varied from 0 to 4375 ppm boric acid storage tank and the the bo demineralized water tank. This section is revised to clarify that 4375 ppm is a nominal value.

The maximum m value is not added adde here since nce the th maximum max is provided as margin to the operating concentration.

op derived by calculating the total boron mass and components and then dividing this value by required to obtain a pH of 7.0 is derived using the boron concentration plus plu margin for other o acids. The required TSP value is then calculated using the TSP concentration and the total containment water volume. As a result, increasing the maximum um boron concentration concentra results in a TSP value of 26,460 lbs. Therefore, COL Appendix A, Technical Specification Specificat 3.6.8 is proposed to be revised to increase the TSP value from 25,920 lbss to 26,460 lb lbs. This value is consistent with the minimum effective TSP required by analysis bring the post-accident containment flood-up water to a pH of 7.0 in ysis to brin D the required time frame.

imp This required TS This into retention fram The function of the PXS and containment pH control is not adversely impacted. The Applicable Applic Applica MODES and Actions are not changed.

TSP mass value supports the design basis accident (DBA) releases of iodine containment such that the pH of the containment sump is adjusted to enhance the o containme ion of the iodine.

A TSP volume of 490 ft3 corresponds to the TSP mass value of 26,460 lbs. The initial loading value for the TSP volume of 560 ft3 contains an additional 14% margin, which was previously 15%. This initial loading TSP volume corresponds to a TSP value of 30,240 lbs, which also Page 9 of 17

ND-20-XXXX Core Makeup Tank Boron Concentration Requirements (LAR-20-004) includes the 14% margin. This total TSP mass value (TSP mass + margin) accounts for degradation of the TSP during normal operation. The 1% reduction in margin over er the original ver margin continues to satisfy the minimum pH requirement, even with an allowance n allowa a llow for degradation of the TSP, and therefore is acceptable from a degradation standpoint.

andpoint. The TSP andpoin assumed density is not changed.

Associated with Surveillance Requirement 3.6.8.2 is a revision of the he testing sample samp size from 2.14 grams at 480 ft and 2.41 grams at 560 ft to 2.19 grams at 490 ft and 3 3 3 d 2.49 grams g at 560 ft3. While the revised volume of 490 ft3 corresponds to 26,460 lbs when accounting accounti for other acid sources, beyond boron, that buildup over time post post-accident, post--accident, this test is simplif simplified acid sources in the test, the minimum required TSP Converting this value to grams and dividing by the T

and does not include the other acids produced post-accident. cident. When only considering boron P at a volume e maximum maxim v

867,830 gallons (converted into liters of water) yields a sample size of 490 ft3 is 15,829 post-accident post-accident cc ize of 2.19 water. This TSP sample size can be used for any TSP volume that is greater the associated TS minimum TSP weight. However, a larger TSP sa g

2 9 lbs.

volume water vo lumee of grams TSP/liter TSP/lite equal to than or equ sample size can be used if R

the TSP volume is verified to be larger thanan 490 ft3 to allow ow the tes test to credit extra TS TSP margin compensating for any degradation that at may have occurred. Therefore, There the larger sample size allows for interpolation. Since a TSP SP volume volum of 560 ft3 is approxim approximately 14% greater than 490 ft , 15,829 lbs is increased by 14% to obtain 18,045 lbs. Using the ssame method for 3

calculating the sample size ass before e yields a sample size of 2.49 grams TSP/liter water for a volume of 560 ft3. Both of these hese sample e sizes are above the TSP concentration conce curve for a pH AFof 7.0 at a boron concentration is conservative relative UFSAR Subsection for the total adversely ration of 3050 ppm, confirming the TSP (an e to the pH requirement.

The surveillance frequency of 24 months for ement.

or both bsection 6.3.2.2.4 is also revised to id al weight of TSP contained in the pH ad elyy impact the ability (and associated sample size) bot SR 3.6.8.1 and 3.6.8.2 is not changed.

identify the revised TSP value of 26,460 lbs adjustment adju baskets. This change does not ity to control the pH of the water in the containment sump and does not change the physical design of the baskets. The change to the TSP value does not affect how ow the TSP mixes with the containment water following a postulated lated accident.

postulated adversely impacted.

mpacted Inspections, Tests, ac w

The dissolution dissol or conditions of extended plant operation chemical makeup of the TSP is not changed. Additionally, the pH this activity as the chemi requirements are not changed.

sts, Analyses, A

time of the TSP of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> is not impacted by change The function of the PXS to control containment pH is not and Acceptance Criteria (ITAAC) No. 2.2.03.08d inspects the D T aske and confirms the total calculated volume of the baskets is 560 ft 3.

pH adjustment baskets The ITAAC doess not ide identify the amount of TSP needed for buffering the containment water postulated accident. This ITAAC is not adversely impacted as the physical baskets following a postulate used to distribute tthe TSP are not changed. Additionally, the physical dimensions and the location baskets are not changed. Safety analyses as described in UFSAR Chapters 6 ocation of the ba and 15 are not adversely impacted as the containment pH control is assumed to be maintained at the requ required pH of 7.0 following a design basis accident in accordance with UFSAR Subsection 6.3.2.1.4 and as described in UFSAR Subsection 15.6.5.3.1.3.

Change Summary Page 10 of 17

ND-20-XXXX Core Makeup Tank Boron Concentration Requirements (LAR-20-004)

The proposed changes do not affect any function or features ability to be used for the prevention and mitigation of accidents. No system, structure, or component (SSC) SC) function is changed. The proposed changes do not involve nor interface with any SSC accidentacciden initiator or initiating sequence of events related to the accidents evaluated in the plant-specific ant--spe ant specific Design D

Control Document (DCD) or UFSAR. The proposed changes do not affect the th radiological radiologic source terms (i.e., amounts and types of radioactive materials released,ased, their release rates and release durations) used in the accident analyses. No system tem or design function f or equipment qualification is negatively affected by the proposed changes.

hanges The changes change do not result in a new failure mode, malfunction or sequence of events nts that could adversely affect a a on safety and security, including the site emergency

4. REGULATORY EVALUATION T

radioactive material barrier or safety-related equipment. The ency ncy plan.

pla he proposed changes do not all for a new fission product release path, result in a new fission have any a adverse allow ssion product barrier failure mode, or create a new sequence of events that would result in significant fuel cladding failures. The proposed changes do not revise any aspects of the e plant that could hav dverse effect ect RAF 4.1 Applicable Regulatory Requirements/Criteria references this appendix unless the proposed amendment under plant-specific (COL Appendix endix A).

nformat irements/Criteria 10 CFR 52, Appendix D, Section VIII.B.5.a allows an applicant ix to depart ed departureure involves a change to or d A) Therefore, NRC approval Tier 2 information.

nformation.

10 CFR 50.36 50.36,, Technical 5

appro pecifications; including limiting condition Specifications; requirements (SRs).

uiremen (SRs) is required applic epart from Tier 2 information, without withou p information, Tier 2* information,, or the Technical Specificatio der paragraphs B.5.b or B.5.c of the section.

or o licensee who prior NRC approval, departure from Tier 1 Specifications, Specificati or requires a license section The proposed change to information involves a change to the Technical Specifications c Tier 2 in requir prior to making the change to establishes the need to have Technical hnical specifications, es conditions for operation (LCOs) and surveillance SRs).. The Core Makeup Tanks (CMTs) and the trisodium phosphate (TSP) provided for pH adjustment satisfy changes have been analyzed proposed change analy sa Criterion 3 of 10 CFR 50.36(c)(2)(ii). The to demonstrate that each continues to provide adequate LCOs LCOs or SRs, as applicable, appli for safe operation of the facility. Therefore, the proposed changes comply com with the requirements of 10 CFR 50.36.

wit 10 CFR R Part Appendix ppend A General Design Criterion (GDC) 4, Environmental and Par 50, Append dynamic design bases, requires, in part, that structures, systems, and c effects desig components nts important importa i to safety be designed to accommodate the effects of and to be D compatible maintenance, These le with w the environmental conditions associated with normal operation, nance testing, and postulated accidents, including loss-of-coolant accidents.

e structures, struc systems, and components shall be appropriately protected against dynamic effects, including the effects of missiles, pipe whipping, and discharging fluids, that n

t the nuclear may result from equipment failures and from events and conditions outside power unit. The proposed changes do not affect the conclusion that SSCs important to safety are designed to accommodate the effects of and are compatible with the environmental conditions associated normal operation, maintenance, testing, and postulated accidents, including loss-of-coolant-accidents. The evaluation performed for the proposed changes demonstrate that the difference in pH that may Page 11 of 17

ND-20-XXXX Core Makeup Tank Boron Concentration Requirements (LAR-20-004) result are considered to be covered by the existing environmental qualification of applicable components. Therefore, the proposed changes comply ply with the requirements of GDC 4.

10 CFR Part 50, Appendix A GDC 14, Reactor coolant pressure e boundary, bound requires requi that the reactor coolant pressure boundary shall be designed, fabricated, fabricated erected, erected, and tests so as to have an extremely low probability of abnormal normal leakage, of rapidly propagating failure, and of gross rupture. The CMT balance designed for the ance line is designe movement of water resulting from routine sampling of the CMT or makeup to the CMT.

The pH adjustment baskets provide adequate TSP to o ensure that containment flood flooding the reactor coolant system and associated iated shall be designed with sufficient margin T

water is buffered to prevent corrosion during long the proposed changes comply with the requirements 10 CFR Part 50, Appendix A GDC 15, Reactor g term floodup conditions. Therefore, ements of GDC 14.

Reactor eactor coolant system d Therefore that design, requires tha and protection systems d auxiliary, control, a syste argin to assure that the design conditions of the R

reactor coolant pressure boundarydary are not exceeded during normal operation, o

including anticipated operational nal occurrences. The CMT b balance line is designed d for the movement of water resulting ulting from routine sampling of the th CMT or makeup to the CMT. Therefore, the proposeded changes comply posed com with the e requirement require of GDC 15.

10 CFR Part 50, Appendix ppendix A GDC 26, Reactivity control sys system redundancy and AF capability, requires, es, in part, thatt two independent reactivity ccontrol co systems of different design principles. es. The second reactivity control systemsystem shall s be capable of reliably controlling the he rate of reactivity changes resulting ffrom planned, normal power changes (including including xenon burnout) to assure ass that the acceptable fuel design limits are not exceeded.

eeded. The second reactivity cont control system is chemical shim (boric acid). The proposed osed change to the CMT upper boron boro conconcentration limit does not impact the ability bility of this system to provide this function since s the analyses typically use the lower limit.

mit. The proposed change to the CMT b boron concentration surveillance frequency vides timely detection of dilution of the CMT to verify operability of the tanks.

provides Therefore, ore, the proposed changes com comply with the requirement of GDC 26.

10 CFR Part 50, Appendix A GDC 27, Combined reactivity control systems capability, capab that the reactivity ility, requires tha re control systems be designed to have a combined capability, ability, in conjunction wiwith poison addition by the emergency core cooling system, of reliably ably controlling reactivity re changes to assure that under postulated accident conditionsns an appropriate margin for stuck rods the capability to cool the core is and with ap D maintained.ed. T core subcritical bcritic contingencies.

continge proposed changes do not affect the means of making and holding the The pro under anticipated conditions and with appropriate margin for ncie Shutdown margin is not affected. Therefore, the proposed changes encies.

ply with the requirement of GDC 27.

comply 10 CFR Part 50, Appendix A GDC 29, Protection against anticipated operational occurrences, requires that the protection and reactivity control systems be designed occ to assure an extremely high probability of accomplishing their safety functions in the event of anticipated operational occurrences. The proposed changes to the CMTs do not change the tanks responses to events. Therefore, the proposed changes comply with the requirement of GDC 29.

Page 12 of 17

ND-20-XXXX Core Makeup Tank Boron Concentration Requirements (LAR-20-004) 10 CFR Part 50, Appendix A GDC 34, Residual heat removal, requires that a system to remove residual heat be provided. The system safety function shall be to transfer fission product decay heat and other residual heat from the reactor core rate such re at a ra that specified acceptable fuel design limits and the design conditions tions of the reactor re coolant pressure boundary are not exceeded. The proposed changesanges to the CMTs do not change the tanks responses to events. Therefore, the proposed oposed changes cha comply with the requirement of GDC 34.

10 CFR Part 50, Appendix A GDC 35, Emergency core cooling, requires that a system to provide abundant emergency core cooling oling whose safety function is to prevented and clad metal-water reaction proposed changes to the CMTs do not Therefore, the proposed changes comply T transfer heat from the reactor core following any loss of reactor coolant at a rate such that fuel and clad damage that could interfere with continued effective core cooling is n is limited to negligible negl amounts ott change the tanks responses re amounts.. The mply with the requirement of GDC 35.

to events.

event R

10 CFR Part 50, Appendix A GDC C 37, Testing g of emergency emerg core cooling system, requires, in part, that the emergency ergency core cooling system mergency syst be designed designe to permit appropriate periodic functional nal testing to assure the opera operability of the system as a whole. The testing of the e CMT boron concentration con at the proposed p

propos frequency is sufficient to assure the e operability system. Therefore, ability of the system ore, the proposed changes comply with the requirement uirement off GDC 37.

AF4.2 4.3 10 CFR Part 50, substances Precedent Precede No precedent 0, Appendix A GDC ecedent is identified Significant identified.

ant Hazards H

DC 4141,, Containment atmo 4

that systemss to control fission products, hydrogen, co concentrat h

which mayy be released into the reactor containment and quality of fission products released to the accidents, cidents, and to control the concentration concentratio atmosphere cleanup, requires oxygen, and other substances ox shall s

reduce, consistent with the functioning of other associated ass be provided as necessary to systems, the concentration th environment following postulated of hydrogen or oxygen and other atmosphere following postulated accidents to assure ubstances in the containment atmospher that containment integrity is maintained. The pH adjustment baskets and mass of TSP ed is sufficient to support the natural removal processes within containment.

provided Therefore, the proposed pro changes comply c with the requirement of GDC 41.

Consideration Determination D The requested (CMT) boron concentration Technical Specification (TS) Surveillance Tank (CMT ueste amendment proposes changes to the upper limit of the Core Makeup Requirement Requireme Requ irem (SR), the mass of trisodium phosphate (TSP) required by TS Limiting Condition for Operation (LCO) and associated SR, and the frequency of performance Conditio of the CMT boron concentration TS SR.

An evaluation to determine whether a significant hazards consideration is involved with the proposed amendment was completed by focusing on the three standards set forth in 10 CFR 50.92, Issuance of amendment, as discussed below:

Page 13 of 17

ND-20-XXXX Core Makeup Tank Boron Concentration Requirements (LAR-20-004) 4.3.1 Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?

ed?

Response: No.

The proposed changes revise the TS SR of the CMT boron on concentration conce uppe upper limit, the frequency of the TS SR of the CMT boron concentration centration upper uppe limit, and the TS and SR of the mass of TSP in the pH adjustment djustment baskets. The pH adjustment baskets are not initiators of an accide nt previously evaluated.

accident eval Inadvertent operation of the CMT during power ower operations is evaluated in because slow leaks can be detected T Chapter 15. However, the analysis of this concentration limit; therefore, the increase doesnt impact this analysis. The change doesnt change the probability of falling is event utilizes the lower boron ed within the new surveillance fast leaks can be detected with the CMT surve T top temperatu temperature alarm.

alarm. Therefore, Therefo boro e to the upper boron concentration limit nge to the frequency of the surveillance ng below the lower boron boro concentration limlimit frequency and the R

consequences of an accidentt previously evaluated because the valuated is not impacted bec parameters credited by the he safety analysis remain within limits in support of meeting requirements.

Post-accident boron n concentration ncentration calculations confirm tha that there is adequate shutdown margin n and that the maximum boron concentration concentratio of the various water AF sources does not cause boron Th equipment qualification on to come out of solution. The program considers onsiders the increase finds ease and fifind differences are negligible for the nds the differe materialss subjected to the increase in boron concentration.

con The non-loss-of-coolant-accident t-accident (LOCA) safety analyses ana typically model minimum CMT boron typica concentration centration considering minimum minimu safeguards and maximum boron safe concentration oncentration for applications conside considering mmaximum safeguards. Since the time considering frame of interest for applications cons consid maximum safeguards is after a sensitive to increases in the maximum CMT reactor trip, these analyses are not se For cases where boron concentration. For wh nominal safeguards are modeled, the increase concentration would be a benefit or have no impact.

rease in the CMT boron concen The changes to the amount of o TSP required is sufficient to buffer post-accident pH in the short-term short-term and short- a long-term long to prevent stress corrosion cracking and help with iodine retention in sosolution within containment in accordance with analysis sumptions used in dose analysis.

assumptions efore the proposed Therefore, p amendment does not involve a significant increase in the D 4.3.2

4. Does ability or consequences of an accident previously evaluated.

probability oes the th proposed amendment create the possibility of a new or different of accident from any accident previously evaluated?

kind o

Response

R No.

The proposed changes do not change the design function of the CMTs or the pH adjustment baskets. These proposed changes do not introduce any new equipment or components that would result in a new failure mode, malfunction or sequence of events that could adversely affect safety-related or non-safety-related Page 14 of 17

ND-20-XXXX Core Makeup Tank Boron Concentration Requirements (LAR-20-004) equipment. This activity will not allow for a new fission product release path, result in a new fission product barrier failure mode, or create a new sequence nce of events that would result in significant fuel cladding failures.

Therefore, the proposed amendment does not create the possibility ossibility of a new or ossibilit different kind of accident from any accident previously evaluated.

aluated.

4.3.3 Does the proposed amendment involve a significant cant reduction in a margin of safety?

Response: No.

from 15% to 14% continues to satisfy allowance for degradation of the T The change to the margin provided for initial itial loading of the pH e TSP. Post-accident calculations confirm that there is adequate maximum boron concentration of the various p adjustment baskets fy the minimum pH requirement, even with cident boron concentrat equate shutdown margin and tha us water sources sou kets concentration does not caus that the cause boron R

to come out of solution as a result of the revision ion to the th CMT boron concentration.

con The non-loss-of-coolant-accident accident (LOCA) safety analyses

-accident an typically typ model minimum CMT boron n concentration concentratio considering considering minimum ssafeguards and g minim maximum boron concentration ration for applications considering maximum ncentration max m safeguards.

Since the time frame ame of interest erest for applications considering maximum safeguards AF is after a reactor or trip, these analyses are not sensitive to increases in in the maximum CMT boron concentration. For or cases where nominal safeguards sa are modeled, the increase in the CMT boron concentration concentratio would be a benefit or have no impact.

The change hange to the frequency of boron concentrat concentration surveillance doesnt change the validation of the CMTs to suppor support safety analysis an initial conditions. No safety analysis limit/criterion is challenged or exceeded by nalysis or design basis acceptance llimit/cr the requested change, thus no margin o of ssafety is reduced.

Therefore, the proposed amendment does not involve a significant reduction in a margin argin of safety safety.

4.4 Conclusions Based ased on the considerations considera discussed above, (1) there is reasonable assurance that the health the public will not be endangered by operation in the proposed ealth and safety of th (2)) such activities manner,, (2 activ will be conducted in compliance with the Commissions ns, and regulations, a (3) thet issuance of the amendment will not be inimical to the common D defense and security ssecu

5. ENVIRONMENTAL CONSIDERATIONS The he requested or to the health and safety of the public.

requested amendment proposes changes to the upper limit of the Core Makeup Tank (CMT)

T) boron concentration Technical Specification (TS) Surveillance Requirement (SR), the mass off trisodium tr phosphate (TSP) required by TS Limiting Condition for Operation (LCO) and associated SR, and the frequency of performance of the CMT boron concentration TS SR.

Page 15 of 17

ND-20-XXXX Core Makeup Tank Boron Concentration Requirements (LAR-20-004)

(i) There is no significant hazards consideration.

As documented in Section 4.3, Significant Hazards Consideration Determination, minatio of this mination license amendment request, an evaluation was completed to determine ermine whether whet a significant hazards consideration is involved by focusing on the three standards set forth ee stand fo in 10 CFR 50.92, Issuance of amendment. The Significant Hazards C Consideration Determination determined that (1) the proposed amendment ment does not involve a significant increase in the probability or consequences of an accident pr previously evaluated; (2) the proposed amendment does not create ate the possibility of a new n or different kind of accident form any accident previouslyy evaluated; and (3) the proposed propos amendment does not involve a significant reduction in a margin of safety. Therefore, it is concluded that the proposed amendment does es not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92(c), 2(c), and accordingly, a finding of no significant hazards consideration on is justified.

tion j (ii) There is no significant change in the types ypes or significant ignificant increase increa in the amounts of any effluents that may be released offsite. e.

The requested amendment proposes poses changes to the upper limit of the Core Makeup Tank (CMT) boron concentration Technicalchnical Specification (TS) Surveillance Surveillan Re Requirement (SR),

the mass of trisodium phosphate osphatee (TSP) required by TS Limiting Cond Condition for Operation Co (LCO) and associated SR, and d the frequency of performance of the CMT boron concentration TS SR. osed changes are unrelated to any aspect of plant R. The proposed construction or operation eration that would introduce any change to e effluent types (e.g., effluents containing chemicals micals or biocides, sanitary system syst effluents, and other effluents) or affect effluents any plant radiological diological or non-radiological no non-radiological gical effluent e release quantities. Furthermore, the relea proposed changes do not affect any effluent release path or diminish the functionality of any design sign sig n or operational features that are cred credited with controlling the release of effluents ents during plant operation. Therefore, it is cconcluded that the proposed amendment does oess not involve a significant change in the ty types or significant increase in the amounts of any effluents that may be released offsite offsite.

(iii) There is no significant signifi increase in individual or cumulative occupational radiation exposure exposure.

The requested equested amendment pro proposes changes to the upper limit of the Core Makeup Tank (CMT) boron oron concentration T Technical Specification (TS) Surveillance Requirement (SR),

the mass of trisodium pho phosphate (TSP) required by TS Limiting Condition for Operation (LCO) and associated ass SR, and the frequency of performance of the CMT boron concentration SR. The proposed changes in the requested amendment do not affect on TS SR or alter any walls, ny walls wa floors, or other structures. Plant radiation zones and controls under 1 CFR 20 pre 10 preclude a significant increase in occupational radiation exposure. Therefore, the proposed propose amendment does not involve a significant increase in individual or cumulative occupational radiation exposure.

cumulativ Based on the above review of the proposed amendment, it has been determined that anticipated construction and operational effects of the proposed amendment do not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant Page 16 of 17

ND-20-XXXX Core Makeup Tank Boron Concentration Requirements (LAR-20-004) increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criteria for categorical exclusion n set se forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental nmenta impact nmental statement or environmental assessment need be prepared in connection with th proposed the prop amendment.

6. REFRENCES None.

T RAF D

Page 17 of 17

Southern Nuclear Operating Company ND-20-XXXX T

Enclosure 2 RAF Vogtle Electric Generating Insertions Proposed rating Plant (VEGP) roposed Changes to Licensing (LAR-20-004)

(LARR-20 20--004 0 )

P) Units 3 and 4 Licensin Basis Documents Do rtions Denoted by Blue Underline and Deletions by Red Strikethrough sertions Omitted text is identified by three asterisks ( * * * )

D (This Enclosure consists of 2 pages, including this cover page)

ND-20-XXXX Enclosure 2 Proposed Changes to Licensing Basis Documents (LAR-20-004)

Revise UFSAR Subsection 6.3.2.2.4, pH Adjustment Baskets, as shown below:

[* * *]

The total weight of TSP contained in the baskets is at least 25,920 26,460 pounds. [* * *]

Revise UFSAR Subsection 9.3.6.2.6, Borated Makeup, as shown wn below:

belo D

The makeup pumps are used to provide makeup at the properr boron concentration to the passiv passive core cooling system accumulators, core makeup tanks, in-containment n-containment refueling water storage tank, and to the spent fuel pool. Makeup to these locations cations is at boric acid concentration as required, which can be varied from 0 to 4375 (nominal) nal) parts per million (2.5 weight percent). A mixture of 2.5 weight percent boric acid and demineralized ineralized eralized water is provided provid by taking suction suct from both the boric acid storage tank and the demineralized lized water tank.

emineralized R

Revise LCO 3.5.2, CMTs - Operating, SURVEILLANCE REQUIREMENTS AF SR 3.5.2.4 Verify and TS d 3700 37 4500 ppm.

g,, Surveillance Requirement (S SURVEILLANCE NCE (SR) shown below:

R as sho fy the boron concentration in each CMT is 3400 ppm, pm.

FREQUENCY 7 days 31 days T

Revise evise LCO 3.6.8, pH Adjus Adjustment, LCO an and SR as shown below:

LCO 3.6.8 The pH adjustmen adju adjustment baskets shall contain 25,920 26,460 lbs of trisodium phosphate (TSP).

(TS

[ * *]

[*

SURVEILLANCE REQUIREMENTS REQUIRE REQU SURVEILLANCE FREQUENCY 3.6.8.1 1 Verify the pH adjustment baskets contain 25,920 26,460 lbs 24 months of TSP.

Page 2 of 2

Southern Nuclear Operating Company ND-20-XXXX T

Enclosure 3 RAF Insertions Vogtle Electric Generating Conforming rtions Denoted by Blue ertions rating Plant (VEGP)

(LARR-20 20--004 00 )

P) Units 3 and 4 ng Changes to the Technical Specificatio (For Information Specification Bases ormation Only)

(LAR-20-004)

O Blu Underline and Deletions D

Omitted text is identified by three th by Red Strikethrough asterisks ( * * * )

D (This Enclosure consists of 4 pages, including this cover page)

ND-20-XXXX Conforming Changes to the Technical Specification Bases (For Information Only) (LAR-20-004)

Revise Technical Specifications Bases B 3.5.2, CMTs - Operating, as shown below:

BASES SURVEILLANCE REQUIREMENTS SR 3.5.2.4 R

The minimum boron concentration on of 3400 ppm assures the CMT safety analysis minimum reactivity tivity control requirements require are met. The he maximum boron concentration tion allowed within each CMT at any time shall be 4500 ppm to prevent event nt overboration.

AF Verification every 7 days 31 dayss that the bo boron concentration in each CMT is within hin the required limits its ensures ensu that the reactivity react control from each ach CMT, assumed in the safety analysis, w will be available as required.

equired. The 7 day 31 day Frequen Frequency is a adequate to promptly identifyfy changes which could occur from me mechanisms m such as in-leakage eakage considering onsidering the provisions for monit monitoring temperature of the e inlet line and nd top of the CMT CMT.. Additionally Additionally, the top of the CMT Additiona has as control room indication ndication and an alarm on increased temperature, which would be indicative of in-leakage.

in T

D Page 2 of 4

ND-20-XXXX Enclosure 3 Conforming Changes to the Technical Specification Bases (For Information Only) (LAR-20-004)

Revise Technical Specifications Bases B 3.6.8, pH Adjustment, as shown below:

BASES LCO The requirements to maintain the pH adjustment baskets 25,920 26,460 lbs of TSP assures that for DBA releases es of iodine into containment, the pH of the containment sump mp will be adjusted to enhance the retention of the iodine.

D SR 3.6.8.1 SURVEILLANCE REQUIREMENTS The minimum amount of TSP SP is 25,920 2 26,460 460 lbs lbs. This weight is based on providing sufficient icient TSP to buffer the post p accident containment water to a minimum m pH of 7.0. Additionally, A the TSP R

weight is based onn treating the maximum aximum vvolume of post accident accid water (867,308 867,830 86 gallons) containing taining the t maximum a amount of boron (3014 3050 ppm) as well as other source sources of acid acid. The minimum required equired ired mass of TSP is 25,920 26,460 lbs at a an assumed assay off 100%.

AF While hile a weight is specified, the normal manne manner to confirm the weight limit imit mit is met is by measuring the volume of th the TSP contained in the pH adjustment baskets. The minimum me measured volume of TSP is 480 490 ft3, which is based on the minimum min required mass of TSP (25,920 0 26,460 26,4 lbs) andnd ass assumes theth minimum density of TSP. The minimum m TSP density is based bas on o the manufactured desnity (54 lbm/ft3), since the density may increase and the volume decrease, during ring plant operation, due tto agglomeration from humidity inside the containment. The TSP volume vo of 560 ft3 at the initial loading (i.e.,

prior to compaction and agglomeration) includes margin (about 1514%)

1514 15 1 %) to account forf degradation of TSP during plant operation.

T The periodic perio verification ve is required every 24 months, since access to baskets is only feasible during outages, and normal fuel the TSP bas ba cycles are scheduled for 24 months. Operating experience has shown tthis Surveillance Frequency acceptable due to the margin in the vvolume of TSP placed in the containment building.

Page 3 of 4

ND-20-XXXX Enclosure 3 Conforming Changes to the Technical Specification Bases (For Information Only) (LAR-20-004)

BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.6.8.2 Testing must be performed to ensure the solubilityubility and buffering buffe ability of the TSP after exposure to the containment ntainment environment. A tainment environme representative sample of TSP from one of the baskets in containmcontainment is submerged in 1.0 +/- 0.01 liter of water er at a boron coconcentration ncentration ation of D

3014 3050 ppm that has been heated ted to a temperature of 71 +/- 5 5°C

°C (160 +/- 9°F). The solution is allowedwed to stand at this temperature for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> without agitation. The solution olution is then cooled coole to 25 +/- 5°C (77 +/-

9°F) and the pH is measured. ed. The solution pH should shou rise to 7.0. A TSP sample size of 2.14 2.19 9 grams is used if the TSP volume is verified to be at least 480 490 ft3 (minimum req required). However, a R

larger TSP sample size can be used sed if the measured m volume is verified to be greater eater than the minimum. For example, if the TSP volume is verified fied to be 560 ft3, then a represe representative sample sam of 2.41 2.49 grams can an be used.

Agitation on of the test solution is prohibited, since an adequate standard AF for the agitation in intensity ntensity cannot be specified. T The time of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> without agitation iss necessary to allow time fo for the dissolved TSP to naturally diffuse through the s solution. In the post LOCA sump sample soluti area, rapid mixing would oc occur due to lliquid flow, significantly d

dec reasing asing the actual amou decreasing amount of time before the required pH is achieved.d.

T Page 4 of 4