ML21334A169

Proposed License Amendment Request Removal of Refueling Water Chemical Additional Tank and Replacement of Containment Buffer Supplemental Information

ML21334A169
Person / Time
Site:	Surry
Issue date:	11/29/2021
From:	Mark D. Sartain Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
21-138A
Download: ML21334A169 (66)

Text

VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261

November 29, 2021

10 CFR 50.90

U. S. Nuclear Regulatory Commission Serial No.: 21-138A Attention: Document Control Desk NRA/GDM: R2 Washington, DC 20555-0001 Docket Nos.: 50-280 50-281 License Nos.: DPR-32 DPR-37

VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 PROPOSED LICENSE AMENDMENT REQUEST REMOVAL OF REFUELING WATER CHEMICAL ADDITION TANK AND REPLACEMENT OF CONTAINMENT SUMP BUFFER SUPPLEMENTAL INFORMATION

By letter dated September 30, 2021 (Serial No.21-138), Virginia Electric and Power Company (Dominion Energy Virginia) submitted a license amendment request (LAR) for Surry Power Station (Surry) Units 1 and 2. The proposed LAR would revise the Surry Units 1 and 2 Technical Specifications (TS) to eliminate the Refueling Water Chemical Addition Tank (CAT) and allow the use of sodium tetraborate decahydrate (NaTB) to replace sodium hydroxide (NaOH) as a chemical additive (buffer) for containment sump pH control following a loss-of-coolant accident (LOCA). By letter dated November 10, 2021, the U. S. Nuclear Regulatory Commission (NRC) informed Dominion Energy Virginia that additional information was required before the NRC would accept the LAR for review. The NRC provided Dominion Energy Virginia an opportunity to supplement the proposed LAR by submitting the requested supplemental information within thirteen working days, i.e., by November 30, 2021.

Dominion Energy Virginia's response to the NRC request for supplemental information is provided in the enclosure. The supplemental information does not affect the conclusions of the significant hazards consideration determination or the environmental assessment included in the September 30, 2021 LAR.

As a noted in the LAR, Dominion Energy Virginia respectfully requests approval of the proposed TS change by September 30, 2022, with implementation of the proposed TS change to coincide with the completion of the fall 2022 refueling outage for Surry Unit 1 and the spring 2023 refueling outage for Surry Unit 2.

Serial No. 21-138A Docket Nos. 50-280/281 Page 2 of 3

Should you have any questions or require additional information, please contact Mr. Gary D. Miller at (804) 273-2771.

Respectfully,

Mark D. Sartain Vice President - Nuclear Engineering and Fleet Support

Commitments contained in this letter: None

Enclosure:

Response to NRC Request for Supplemental Information

Attachments:

1. Proposed Surry Unit 1 UFSAR Update (Interim)

2. Proposed Surry Units 1 and 2 UFSAR Update (Final)

COMMONWEAL TH OF VIRGINIA )

COUNTY OF HENRICO )

The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Mr. Mark D. Sartain, who is Vice President - Nuclear Engineering and Fleet Support, of Virginia Electric and Power Company. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that company, and that the statements in the document are true to the best of his knowledge and belief.

Acknowledged before me this,l L '14 day of l\\1We.Mbe-r-, 2021.

My Commission Expires: °:J v' I> 20Z3.

GARY DON MILLER Commonw ealth of Virginia Notary Public Notary R b

• Reg. # 7629412 /

My Commission Expires August 31, 20 Serial No. 21-138A Docket Nos. 50-280/281 Page 3 of 3

cc: U.S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Avenue, NE Suite 1200 Atlanta, GA 30303-1257

Mr. L. John Klos NRC Project Manager - Surry U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 09 E-3 11555 Rockville Pike Rockville, MD 20852-2738

Mr. G. Edward Miller NRC Senior Project Manager - North Anna U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 09 E-3 11555 Rockville Pike Rockville, MD 20852-2738

NRC Senior Resident Inspector Surry Power Station

State Health Commissioner Virginia Department of Health James Madison Building - 7th floor 109 Governor Street Suite 730 Richmond, VA 23219 Serial No. 21-138A Docket Nos. 50-280/281

Enclosure

RESPONSE TO NRC REQUEST FOR SUPPLEMENTAL INFORMATION

PROPOSED LICENSE AMENDMENT REQUEST

REMOVAL OF REFUELING WATER CHEMICAL ADDITION TANK AND REPLACEMENT OF CONTAINMENT SUMP BUFFER

Virginia Electric and Power Company (Dominion Energy Virginia)

Surry Power Station Units 1 and 2 Serial No. 21-138A Docket Nos. 50-280/281 Enclosure

RESPONSE TO NRC REQUEST FOR SUPPLEMENTAL INFORMATION

License Amendment Request - Removal of Refueling Water Chemical Addition Tank and Replacement of Containment Sump Buffer

Surry Power Station Units 1 and 2

BACKGROUND

By letter dated September 30, 2021 (Serial No.21-138), Virginia Electric and Power Company (Dominion Energy Virginia) submitted a license amendment request (LAR) for Surry Power Station (Surry) Units 1 and 2. The proposed LAR would revise the Surry Units 1 and 2 Technical Specifications (TS) to eliminate the Refueling Water Chemical Addition Tank (CAT) and allow the use of sodium tetraborate decahydrate (NaTB) to replace sodium hydroxide (NaOH) as a chemical additive (buffer) for containment sump pH control following a loss-of-coolant accident (LOCA). By letter dated November 10, 2021, the Nuclear Regulatory Commission (NRG) informed Dominion Energy Virginia that additional information was required before the NRG would accept the LAR for review and provided an opportunity to supplement the proposed LAR by providing additional information to address the items detailed in their letter.

Dominion Energy Virginia's response to the NRG request for supplemental information is provided below.

NRC Request No. 1

A description of how the Na TB (sodium tetraborate decahydrate) will be stored, such as the number of baskets, size, detailed x-y-z location, and how they are designed to contain the Na TB while allowing access for the water to dissolve it.

Dominion Energy Virginia Response

Seven (7) baskets will be installed in each of the Surry Unit 1 and Unit 2 Containments and will contain the required amount of NaTB chemical. Each basket will have nominal dimensions of 6' x 5' x 1.5'. The baskets will be installed on the (-)27'-7" elevation of the Surry Unit 1 and Unit 2 Containments near the annulus, as well as near the lncore Instrumentation Room. The baskets use a fine mesh supported by a perforated plate to contain the NaTB chemical that allows the containment sump water to passively dissolve the NaTB. The perforated plate and fine mesh system encompass the four basket side walls and the basket bottom. The planned installation locations of the baskets in the Surry Units 1 and 2 Containments are shown in Figures 1 and 2, respectively, and are provided for information. It should be noted that the locations could be adjusted during the design change implementation process due to unforeseen installation issues.

Page 1 of 12 Serial No. 21-138A Docket Nos. 50-280/281 Enclosure

r-:='~.:.=1 g 1l1

E E

D D

o:xec:B PUIW a -ir*r

IBIIBf,E-*-----.. -..

lf.'t'llilitllllifr,r.:tf','ff'......

1...,..* - l!"JlliJ!l,!ll,sll6!NVf*iEl'lllll

• -* 11!'1'111~1"rfl1EPU

• -..-.-;,a;a;,-yr,11.....

!UN _!l,_ *l?'-7' ac.........,

MII\\CH. LDC, - REl'ClllR ClllfT. PI.J'N EL, C-127'-7' SIJNIY PDWEJI STATION - UNIT I 1***.:

Figure 1 - Currently Planned NaTB Basket Locations in Unit 1 Containment

Page 2 of 12 Serial No. 21 - 138A Docket Nos. 50-280/281 Enclosure

F

() '"ou*

~-",,, Ii;,..,..

'\\ I

.. ~:. 1. t'ITIIU.... MI 1"11 \\ \\ ~~... ---. /.,~

.,>:>f.Y......._____ ---.,

t Mm~,. ~>3//V

--21 \\ _ 'f ig\\, If.< /---.:..~,/,

~ - r,.. * *

)<

\\ '\\

~~ \\Q,.,,

'!!~~"""', /\\. ~

.,.,.. u t ~

1-,,c.. 1_.,,.. ~"-"'T

~

t;, 1, I t",IL...,r

i>FTAc.HF.D PLAN EL. -13' ~O'

'"'l" P !.ot.'TT'<

., P.MI' !~-n

.:,ei':fs'ITbt' Tll U lllll. lU f'l,t-i~i

IC,"11.V ***"*T

,.. ~ SJIU'l'

......,;y,,.,.,1,,

-irt'.rt 1111nT caci...t.1s,__." H DTH

<llt'lt~J...:I ll.$\\ ftlP'U l f Nf.C :IIICS

• rH, II,.

• TJ_.;-}/ '-~~i~=r~,_~ iml

-Ut-i:o u-n-11,t,

• 1t"/':Jll ~~W: 1ff *

x. "'w-,-..w~ -~

";i~~~"=°lf;~ *

~J W-1:t ~ *;r:r-J'd'l~A'\\~*

.,. ~" /.<J.,,,,,.. / ~'9J:1N l;l"H'li1a * ~'llll'~SJ:'RV l.,..

, ~.i~ -H.i:."'~~ --~ 1/

~ r-c.**** \\, '-\\- - '....,; ~

PlAN EL *27'-r MACH LOC PLAN EL {-)27' -7 1 REACTOR CONT

SURRY POWER STATION - l.NH Z

!11111:!.lllf'"' -

l1wua - 1J~ F'IIHO ~-*

F

Figure 2 - Currently Planned NaTB Basket Locations in Unit 2 Containment

Page 3 of 12 Serial No. 21-138A Docket Nos. 50-280/281 Enclosure

NRC Request No. 2

A summary of the post-Loss of Coolant Accident (LOCA) borated water sources, with a description of the boron concentrations considered.

Dominion Energy Virginia Response

The borated water sources considered as part of the buffer replacement project are provided in Table 1.

TABLE 1 - BORA TED WATER SOURCES

1. Parameter Units Minimum Maximum

Refueling Water Storage Tank (RWST)

1.a Volume gal 361,916 388,917

1.b Boron Concentration ppm 2,277 2,525

Reactor Coolant System (RCS)

2.a Volume gal 63,018 67,380

2.b Boron Concentration ppm 0 2,525

Safety Injection Accumulators and Associated Piping (S/As)

3.a Volume - SIAs gal 21,682 23,201

3.b Volume - SIA Piping gal 1,104 1,104

3.c Boron Concentration ppm 2,228 2,525

SJ Piping (sum of a/13 loops)

4.a Volume gal 369 369

4.b Boron Concentration ppm 0 2,525

Page 4 of 12 Serial No. 21-138A Docket Nos. 50-280/281 Enclosure

NRC Request No. 3

A summary of the sources of other acids and bases included in the post-LOCA pH calculation, and at least a reference to how they were calculated.

Dominion Energy Virginia Response

Other (non-boric acid) acids and bases considered in the post-LOCA pH calculation are summarized in Tables 2 and 3, respectively.

TABLE 2-NON-BORIC ACIDS INCLUDED IN POST-LOCA PH CALCULATION

1. Acid Source Reference(s}

1 Nitric Acid Irradiation of water §2.2.4 of NUREG/CR-5950

2 Hydrochloric Acid Irradiation of chloride bearing §2.2.5.2 of NUREG/CR-5950 cables

• ORIGAMI in SCALE 6.2.3 3 Hydriodic Acid Released core inventory * §3.2 of Reg Guide 1.183

• §2.2.2 of NUREG/CR-5950

TABLE 3-BASES INCLUDED IN POST-LOCA PH CALCULATION

1. Base Source Reference( s}

1 Hydroxide Released core inventory * §3.2 of Reg Guide 1.183 Cesium

• ORIGAMI in SCALE 6.2.3

• §2.3.1 of NUREG/CR-5950

2 Lithium RCS water Plant chemistry procedure Hydroxide

Page 5 of 12 Serial No. 21-138A Docket Nos. 50-280/281 Enclosure

NRC Request No. 4

A description of the methodology and results for calculating pH and the required Na TB quantity, or the analysis.

Dominion Energy Virginia Response

The pH / buffer quantity analysis considers all species in the containment sump solution to be in equilibrium, i.e., it is based on steady state conditions. The sump pH is computed using guidance from NUREG/CR-5950.

The concentration of negatively charged species (anions) must equal the concentration of positively charged species (cations) for electroneutrality in the sump. The sum of negative charges for the charge balance is determined from the molal concentrations of anions B(OH)4*, B2(OH)1*, 83(QH)10*, 84(QH)1i* or 85(QH)1a3*, OH*, NQ3*, Cl*, and 1-.

The sum of positive charges for the charge balance is determined from the concentrations of H+, Na+, Cs+, and u+. The ionic activity product constant of water is modeled using the Marshall-Frank correlation 1.

Boric acid speciation is based on the temperature dependent molal-equilibrium quotients reported by Palmer 2. The concentration of boron in solution based on the total mass of boric acid and NaTB must be equal to the concentration based on the contribution of all boric acid species.

Equilibrium sump conditions are determined using an analytical model which was benchmarked to site-specific buffer testing using the same buffer as will be installed.

Different inputs are utilized based on whether the calculation is determining: 1) solution pH based on buffer quantity, or 2) buffer quantity based on desired solution pH. The model iterates boric acid speciation, and either NaTB mass or pH until convergence is achieved for the boron mass balance and charge balance equations.

The amount of NaTB required for long-term post-LOCA containment sump pH control (i.e., to ensure the sump pH remains at or above 7) is approximately 10,760 lbm. This quantity is determined using the methodology described above, as well as the inputs described in the response to NRC Request No. 5.

1 Marshall, W. L., and E. U. Franck, "Ion Product of Water Substance, 0-1000°C, 1-10,000 Bars New International Formulation and Its Background," Journal of Physical and Chemical Reference Data, Vol.

10, No. 2, pp. 295-304, 1981.

2 Palmer, D. A., Benezeth, P., and D. J. Wesolowski, "Boric Acid Hydrolysis: A New Look at the Available Data," PowerPlant Chemistry, v. 2(5), pp. 261-264, 2000.

Page 6 of 12 Serial No. 21-138A Docket Nos. 50-280/281 Enclosure

NRC Request No. 5

For each case considered, a description of how input values and ranges were selected for the water and chemicals used in the calculations (e.g., water, boron, NaTB, and other acids and bases).

Dominion Energy Virginia Response

• Determination of NaTB Required

The following inputs were used to determine the NaTB required to ensure the minimum required sump pH at the time when Recirculation Spray is credited for iodine removal and at 30 days for 1-train of Engineered Safety Features (ESF) and full ESF. These inputs conservatively bias high the quantities of acids and bias low the quantities of bases.

- Sump pH= 7.0

- Maximum mass of boron/boric acid in the containment sump at time of interest for the ESF scenario being investigated

- Minimum lithium concentration in RCS

- Hydrochloric acid generation due to cable irradiation at time of interest (biased high)

- Nitric acid generation due to water irradiation at time of interest (biased high)

- Maximum core iodine release at time of interest

- Minimum core cesium release at time of interest

- Minimum NaTB chemical equivalence

• Determination of Maximum Sump pH Values

The following inputs were used to determine the maximum sump pH at select times for 1-train ESF and full ESF cases. These inputs conservatively bias high the quantities of bases and bias low the quantities of acids.

- Maximum NaTB mass at time of interest

- Minimum mass of boron/boric acid in the containment sump at time of interest for the scenario being investigated

- Maximum lithium concentration in RCS

- No hydrochloric acid generation due to cable irradiation

- No nitric acid generation due to water irradiation

- No core iodine release

- Maximum core cesium release at time of interest

- Maximum NaTB chemical equivalence

Page 7 of 12 Serial No. 21-138A Docket Nos. 50-280/281 Enclosure

NRC Request No. 6

An explanation for how the mass of Na TB would be measured in order to meet the proposed requirement in Technical Specification 3.4.A.4.

Dominion Energy Virginia Response

Each basket has indication marks to assist in visually identifying the minimum acceptable level of NaTB to be added in the field. The basket mark indicating the minimum level is higher than the minimum required level associated with the specified TS minimum buffer mass, based on the minimum buffer density, which ensures sufficient buffer will be installed in containment.

NRC Request No. 7

A description of the test that will be performed to verify that the Na TB in the baskets provides adequate pH adjustment, according to the proposed sampling test #4 in the license amendment submission, Table 4.1-28, "Minimum Frequencies for Sampling Tests."

Dominion Energy Virginia Response

A NaTB buffer sample will be taken from each of the seven baskets during each refueling outage (RFO). Using the sample, a known quantity of buffer will be added to a known quantity/concentration of borated water. The test will be satisfactory provided the resultant solution pH is 7.0 or greater. The mass of the NaTB added to the test is based on the initial prototypical pH adjustment / buffer testing that was previously performed in support of the buffer replacement.

NRC Request No. 8

Revisions to Final Safety Analysis Report Sections such as 6. 1 (General Description),

6.2.3.3 (Chemical Additives), and 6.3.1 (Spray System), which describe the use and characteristics of sodium hydroxide as the chemical additive.

Dominion Energy Virginia Response

The proposed updates to the Surry Unit 1 and Unit 2 Updated Final Safety Analysis Report (UFSAR) to reflect the proposed changes described in the LAR are provided in Attachments 1 and 2, respectively. The UFSAR updates will be implemented in accordance with the design change update process associated with the design change packages implementing the removal of the CATs and the replacement of the containment sump buffer. The proposed Unit 1 UFSAR revision is an interim revision

Page 8 of 12 Serial No. 21-138A Docket Nos. 50-280/281 Enclosure

that reflects the differences between Unit 1 and Unit 2 following the implementation of the Unit 1 modifications during the fall 2022 refueling outage (RFO). The Unit 2 UFSAR revision reflects the final plant configuration after the modifications have been completed for both units following the Unit 2 spring 2023 RFO. The Surry Unit 1 and 2 site Plot Plans in the UFSAR will also be revised to reflect the removal of the CAT at each unit.

NRC Request No. 9

A reference to the current GL 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors" chemical effects assessment of record for Surry Units 1 and 2 that supports the license amendment's statement of reducing chemical precipitate, and a discussion, as appropriate, describing how this change may effect post-LOCA sump volumes.

Dominion Energy Virginia Response

Generic Letter (GL) 2004-02

The Surry GL 2004-02 chemical effects analysis is summarized in Dominion Energy Virginia's letter to the NRC dated February 27, 2009 [ADAMS Accession No.

090641018]. A new calculation was developed in support of the CAT removal / buffer replacement design change to assess the impact on Surry's resolution of Generic Safety Issue (GSl)-191 / GL 2004-02 as a result of changing the buffer from sodium hydroxide to NaTB. The assessment was based on both industry literature and utilizing the existing chemical effects models to predict aluminum dissolution following buffer replacement. The design sump pH limits do not change with buffer replacement; however, the pH of the initial spray from the RWST is greatly reduced without adding NaOH. The reduction in the initial spray pH results in less aluminum dissolution and therefore less subsequent precipitation. The overall conclusion of the assessment is that the design basis strainer head loss testing that was performed using chemical precipitate quantities based on a sodium hydroxide buffer remains bounding for the use of the Na TB buffer.

Post-LOCA Sump Volume Discussion

The CAT volume ranges from approximately 3,700 to 4,650 gallons but was not included in the minimum flood level used for the Emergency Core Cooling System (ECCS) net positive suction head (NPSH) analysis. Therefore, removal of the CAT does not impact the flood level used for the NPSH analysis. The maximum flood level analysis includes the volume of water from the CAT. The impact on maximum flood level of the total basket volume including solid NaTB (45 ft3 metal + chemical volume per basket) was evaluated. This evaluation accounts for the removal of the credited volume from the CAT, as well as the volume of water displaced by the addition of the

Page 9 of 12 Serial No. 21-138A Docket Nos. 50-280/281 Enclosure

Na TB baskets. The addition of the total basket volume including solid Na TB is less than the volume from the CAT; therefore, it was determined the maximum flood level remains below the design basis value after buffer replacement.

NRC Request No. 10

General structural arrangement drawing(s) of the new containment chemical baskets documenting the basket support structure, including basket weight and basket design details.

Dominion Energy Virginia Response

The Na TB baskets are designed of stainless steel (Type 304 SS) and have a frame with a fine mesh and perforated metal plate enclosure. The baskets are designed with four caster wheels (type 304 SS and 2205 Duplex SS) to facilitate the movement of the baskets during outages, if required. The baskets are designed with a raised bottom to provide additional surface area to dissolve the NaTB in sump water and to avoid loss of NaTB due to any inadvertent water spillage or leakage on the containment floor. The baskets include internal level indication used for inventory verification and ease of adding NaTB, as well as a removable cover w_hich is provided with a drip edge to ensure that accumulated leaks/condensate above the baskets are directed away from the NaTB inside the basket.

The weight of one filled NaTB basket is approximately 3,975 lbs., and the weight of one fully assembled empty NaTB basket is approximately 1,425 lbs.

A picture of baskets similar to the planned baskets is provided in Figure 3.

Figure 3 - NaTB Basket (Example)

Page 10 of 12 Serial No. 21-138A Docket Nos. 50-280/281 Enclosure

NRC Request No. 11

Objective evidence (data, calculations) to support the statement in the license amendment that "The design loads for the baskets are generated by combining the unfactored load effects of dead loading, chemical pressure loading, and seismic loading...[the] baskets were evaluated to maintain their structural integrity during a Design Basis Earthquake event concurrent with post LOCA elevated temperature conditions." This information should also state the applicable design code applied, applicable design loads, load combinations used for the design, a summary of computed stresses, and margins showing the structural integrity of the baskets.

Dominion Energy Virginia Response

The basket members and connections are analyzed to meet applicable licensing and design basis requirements in the UFSAR and Dominion Energy Nuclear Engineering Standard (ONES) DNES-STD-CE-0046, AISC 9th Edition, "Manual of Steel Construction". In accordance with the AISC 9th Edition and UFSAR Section 15.2.4, Seismic Design, allowable stresses for members may be increased by 1/3 for earthquake loading using the applicable load combinations. When considering the 1/3 increase for earthquake loading, the maximum member interaction for members, connections, welds, wheels, bolts, and anchor bolts is less than the required 1.0. While not required, additional checks were conservatively performed on the members and connections using ASCE 8-90, ASCE 7-88, and Design Guide 24. In all cases, the additional checks satisfy the code requirements.

Justification for Non-safety - Quality (NSQ) Basket Design:

As a result of this modification, baskets are designed to hold the NaTB buffering agent and are to be placed in the Containment basement. The NaTB buffering agent, which is procured as Safety Related due to its function of providing pH control for the containment sump and to retain radioactive iodine in solution, can perform its design function without the presence of the baskets. Therefore, the purpose of the baskets is to contain the NaTB buffering agent. A failure modes and effects analysis was performed to demonstrate credible failure of the basket does not impede the NaTB buffering agent from performing its design function. Any buffering agent that was to escape from the basket would improve the dissolution rate.

DNES-AA-MEL-4001, "Determining the Safety Classification of Structures, Systems, and Components," has been reviewed to determine the safety classification of the baskets. Per DNES-AA-MEL-4001, Attachment 2, Code 5.2.6 and 5.2.26a, the baskets are classified as Non-safety Quality (NSQ) (i.e., components that are not safety related but have special quality/regulatory requirements). Code 5.2.6 is defined as, "Components that are NOT functionally safety related, but that are required to be seismically restrained, supported or anchored to prevent damage to nearby safety

Page 11 of 12 Serial No. 21-138A Docket Nos. 50-280/281 Enclosure

related equipment." NSQ Code 5.2.26a is defined as, "Those components, systems, and structures that are NOT safety-related, but which are designed and installed as seismically qualified to ensure the required level of functionality during and/or after a DBE [Design Basis Event]. This definition includes components that are required to remain functional (i.e., some or all of their active and/or passive functions must remain intact) during and/or after a DBE. This requirement may be the result of a SAR/licensing commitment or just the desire to achieve enhanced reliability. This includes "active" components that must remain fully operational, as well as "active" and "passive" components that only have to maintain system pressure boundary." Per DNES-AA-MEL-4001, a Design Basis Event (DBE) includes the following: normal operation, anticipated operational occurrences/transients, design basis accidents, external events, and natural phenomena. Therefore, the baskets are designed to meet Seismic 11/1 requirements. Additionally, the baskets are designed to maintain their structural integrity during a DBE.

NRC Request No. 12

A discussion on the high energy lines in the vicinity of the baskets, and how the baskets are protected from HELB effects (jet impingement and pipe whip) is not included.

Dominion Energy Virginia Response

To ensure the NaTB baskets are not adversely affected or adversely affect the containment sump strainers, the planned installation locations for the NaTB baskets have been chosen to avoid placement in areas that could be affected by HELB effects in the containment basement. Protection against the effects of blowdown jet forces and pipe whip resulting from a postulated pipe rupture of the Reactor Coolant, Pressurizer, Main Steam, and Feedwater System piping is provided by a combination of distance, restraints, and barriers. Specifically, high energy piping is protected / isolated by missile barriers and restrained to limit pipe whip. The baskets located in the containment annulus area are protected by the crane wall. Baskets that are not protected by the crane wall are located so that the impingement pressure from an HELB would not affect the baskets such that the ability of the Na TB buffer to perform its design function would be impeded based on the zone of influence (ZOI) radius. Therefore, the baskets are sufficiently protected from the effects of HELBs through the use of barriers, restraints, and distance.

Page 12 of 12 Serial No. 21-138A Docket Nos. 50-280/281 Enclosure

Attachment 1

PROPOSED SURRY UNIT 1 UFSAR UPDATE (INTERIM)

Virginia Electric and Power Company (Dominion Energy Virginia)

Surry Power Station Unit 1 Revision 50.0 1-U pdated On I ine 10/31/18 P UF AR 5.3-4

installing the c lo sed side of a spectacle flange. The maximum purge rate through this path is limited to 20,000 cfm as the filter a lso erves the Auxiliary Building eneral xhaust.

5.3.l.4 Design Evaluation Whenever the three main recirculation fan and coil units, the three CRDM fan and coil units, and the main coo lant pump coo lin g systems are operating, the conta inm ent bulk air temperature w ill be maintained below 125°F. Two f the three fan in the recirc ul at ion system will continue to operate under limited main coolant leakage cond itions that result in containment pressure. up to but not exceeding the Consequence Limiting afeguard (CL ) high-high containment prcssur actuation setpoint ( ection 7.5.1.2). The third fan wi ll continue to operate, if normal station power is availabl, until stopped either manually or by actuation of an electrical fault protecti n device. This may provide sufficient heat removal to permit reactor shutdown under limit ed leakage cond itions without re orting to c I t1 ray injection......---- -.

REMOVE The inside containment filter units will remove the a irb orne iodine an par 1culate radioactivity that could result from nominal operational leakage during subatmospheric operations.

The purge system pr vides the capability to change the containment air and remove radioactivity, if required, before entry for refueling and maintenance. The purge system i design d for one air change per hour and to maintain a minimLJm of 60 ° inside the containment.

5.3.1.4.1 Incident ontrol During normal operation of the plant the containm ent purge y tern is not in u e.

After unit shutdown and coold wn, purging of the containment can take place. The purge exhaust a ir may be directed to either the non-safety-related or safety-re lated ventilation filters in the auxi li ary building if fuel is being handled inside containment, but no :filtrati.on is credited in the analy i. The analysi

• of the fuel handlin g accident in containment does not require that containment integrity be e tablished prior to fuel movement. The purge de ign flow through the non-safety-related fi lter is 20,000 cfm with a limit of 30,000 din through the safety-related filters when containment int egrity is established. If containment integrity is not e tablished, the maximum purge exhaust rat equals the maximum safety-re lated fan flow limit of 39,600 cfm.

The physical design and installation of the duct system preclude exceeding these limit. The discharge of the safety-related filters and non-afety-re lated filter are monitored by the same system for radioactivity prior to release. hould a LOCA signal from the other unit be received, the air-operated isolation dampers will fail closed and allow the safety-re lated filters to treat the air exhausted from the ECCS areas. As described in ectio n 9. 13.4. 1, if a safety injection actuat ion occurs and auto alignment of the ventilation system is defeated, manual action is required to rea li gn the system to the ECCS filtration mode. An alarm is recejved in the main control room if the purge is not realigned fo ll win g a safety injection signal. This condition i not expected however, ince defeating the automatic realignment is no I nger credited in the fuel Revision 51.05-Updated Online 07/30/20 SPS UFSAR 6-iv

REPLACE Chapter 6: Engineered Safeguards

6.3 -26a

Figure 6.1-1 Unit 1 ng in eered afeguards ystems.....,.................. 6.1-4 Figure 6. 1-2 Unit 2 Eng i11eered afeguards ystems........................ 6. 1-5

" igllre 6.2-1 afety Injection System.................................... 6.2-55 Figure 6.2-2 Protect ion Prov ided by Various ombinations of afeguards Components.................................... 6.2-56 Figure 6.2-3 Avai lable NP H LH l Pump NP H Available Analysis.......... 6.2-57 Figure 6.2-4 ont a inment Pressure LHSI Pump NP H Avai lab le Analysis...... 6.2-57 Containment emperatures H I Pump NP H Available Analysis.. 6.2-58 Total RSHX Heat Rate LI-ISi Pump NP H Available Analysis..... 6.2-58

Unit l Recirculation Spray Subsystem........................ 6.3-27 Unit 2 Recircu lation pray ubsystem........................ 6.3-28 Figure 6.3-4 Pip ing and ornponents Elevati ns pray Systems............... 6.3 -29 Typical - General tructural and Piping Arrangement Recirculation pray and Low Head afety Injection Systems Outside the Reactor ontainment..............

Figure 6.3-6 Outside RS Pump NPSH Available Ana lysis D +IL at 10.3 ps ia, 25°F W.............................. 6.3-31 Figure 6.3-7 Outside RS Pump NP H Available Ana lysis DEl L at l 0.3 psia, 25°F W.............................. 6.3-3 1 F ig ure 6.3-8 Outside RS Pump NPSH Available Analysis DEHL at 10.3 psia, 25 °F W.............................. 6.3-32 F igure 6.3-9 Outside R Pump NPSH Available Analysis DEH G at 10.3 ps ia, 25°F W.............................. 6.3-32 Figure 6.3 - 10 I nsi de RS Pump NP H Available Analy is DEP at 10. 1 psia, 70 °F SW............................... 6.3-33 F igure 6.3-l l Inside RS Pump NPSH Availab le Analysi

• DEPSG at 10.1 psia, 70 °F W............................... 6.3-33 F igure 6.3-12 nside RS Pump P H Availab le Analysis DEP G at 10. 1 psia, 70°F W............................... 6.3-34 F igure 6.3-13 Inside RS pump NP H Available Analy i

• I* IO O I I It I I I I I*

• o *I, o I I I I Unit 2 ontainment Spray ubsy s tem.........................

INSERT Revision 51.05-Updated Online 07/30/20 PS UFSAR 6.1-1

CHAPTER 6 ENGINEERED SAFEGUARDS

6.1 GENERAL DESCRIPTION

Note: As required by the Renewed Operating icenses for Surry Units 1 and 2, issued March 20, 2003, various system struct ur es, and components discussed within this chapter are subject to aging management. The programs and activities necessary t manage the aging of these systems, structures, and components are dlscu sed in hapter 18.

The eng.ineered safeguards, together with the containment ( hapter 5), protect the public and the stat ion in the event of the design-basis accident, as defined in ect ion s 14.5.1.2 and 14.5.5. The engineered afeguards are design d to minimize the acc id ent by performing the fol low in g three functions:

1. Supply borated water to the reactor coo lant system t cool the core, decrease reactivity, Jim it fuel rod c laddin g temperat ur e, limit the metal-water reaction, and ens ur e that the core remains intact.

2. L imit the driving p tential, including differential pressure and time duration, for leakage out of the containment structure.

3. Reduce the concentration of airborne fission products avai lab le for leakage.

The first function is satisfied by the timely, continuous, and adequate supp ly of borated water to the r actor coolant system and the reactor core. he second function is satisfied by the provision of heat sinks for the condensation of steam released in side the containment, the inherent depressmization of the containment below atmospheric pressure following the de ign-basis accident, and means for maintaining th c ntainment at subatmospheric condition for an extended period of time. The third function is satisfied by provi.ding chemical additiv (NaO.E )

to the containmen to enhance the spray removal of radioactive iodine f*

INSERT and

1. A safety inj ection system (

reactor coolant loops.

2. Two separate low-head safety injection sub ystems, eithe r of which provides long-term removal of decay heat from the reactor core.

3. Two sepatate subsystems of the spray system (containment spray and recirculation spray) that operate together to reduce the containment temperature, return the containment pressure to subatmospheric, and remove heat from the containment. The recirculation spray sub sy tern maintain the containment subatmo pheric and transfers heat from the containment to the service water system (Section 9.9).

Revision 51.05-pdated Online 07/30/20 P UF AR 6.1-2

A composite schematic diagram of the engineered safeguards systems is h wn in Figures 6. 1-1 and 6.1 -2 fi r Units l and 2 *e p ct iv ely.

The safety injection system provides for the charging of borated water to the reactor coolant system from the accumulators following a LO A. The three accumulators are se lf-contained and are designed to supply water as soon as the reactor c olant system pres ure drops below 600 psig.

Additional makeup to the reactor coolant system is provided by the charging pumps, operating in the safety inject ion mode, and the low-head safety injection pumps. Bot h the charging and low-head safety injection pumps a re lo cated out ide the containment, are driven by an electr ic motor, are capable of being rapidly energized or operated, and are powered from the emergency power buses. The pumps also ensure an adequate supply of borated water for an extended period of time by recircu.lating water from the containm ent sump to the reactor core through two separate flow paths.

The containment spray subsystem supplies chilled borated water to the conta inm ent immediately following the receipt of the safeguards initiation signa l. This ubsystem includes two full-capacity, e lectric-motor-driven containment spray pumps that are located outside the containment and are supp li ed with power from the emergency buse. The containment spray pumps supply chilled water from the refueling water storage tank to the containment. E ither pump is capable of furnishing sufficient spray water to prevent overpressurizing the conta inm ent strncture. A chemical addition tank is balanced hydraulically with the refueling water storage tank...------,

and provides a flow of sodium hydroxide solution to increase the alka linity of the containment INSERT spray and recirculated pray to ensure effective removal of radioactive iodine

The recirculation spray subsystem recirculates water from the containment sumps

• rough service-water-cooled recirculation spray heat exchangers to the recirculation spray headers. Two of the four 50% design capacity, motor-driven recirculation pray pumps are located outside the containment. All four of the rec irculat ion spray coo lers are located in ide the containment and transfer conta inm ent heat to the service water system ( ection 9.9).

The containment spray and reci rcul ation spray subsyste s arc capab le of reducing the containment pressure to subatmo pheric in less than 60 minute, thu terminat in g all out leakage to the environment. Thi origin a l design criterion was modifie in conjunction with the analyses for implementation f the a lt ernativ e o urce term. The modi 1ed criteria requ ire that, fo ll owing the LOCA, the containment pres ure be less than 1.0 psig ithin 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and less than 0.0 psig within 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. he radiolo gical c n equences analysis de onstrate acceptable results provided the containment pre sure does not exceed 1.0 psig for the *. terval from 1 to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> following the Design Basis Accident. Beyond 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, containment pre sure is assumed to be le s than 0.0 psig, terminating leakage from containment.

INS ERT The containment vacuum system removes ny ubsequent air inleakage after the containment pressure has been reduced to subatmos heric. Because of the inherent low-leakage design f the containment, the use of the vacuum p mps will probab.ly not be required for severa l odium Tetraborate Dccahydr te (Na TB) is torcd in baskets in ide ntainment to increase the a lkalinity of the surnp water produc d during an eve nt whi ch exceeds the L high-high containment pressure actuation setpoint. The NaTB solution is recirculated by the rec ir c ul ation spray subsy tem t ensme effective remova l of radioactive iodine (Unit 1).

a * * *

• I l * ~ I._ 1... fl. \\. L L L. 1.... t,._.L.t.. i,_.. --" J,._ J,_ _j,_ J.. J,...J..._.J.......L......L..

REPLACE WITH INSERT A Figure 6.1-1 T 1 E GINEERED SAFEG ' A RDS SYSTEMS

OUf!llbEl£,lclllA--'i..::~==='--I i

~

! 0

! LOOP{-*---tljr-~~~ -~ 7..!~J!F ---.l

! i~ [ACS) 0 w

INS(DE. N 0 1-I SHIR.D

= """"'l !

I j

i ~:: -.......... :=~~~=~+.----r.i~--' CZI

• I.EC '"O 1-gics) CZI

! C

'Tl

(/)

LOCAL Wl)S s.u&U

REI:IRClUJ1CtlSl'RAY C00t.ERli IOCITE: 'RMT~

51-f:OWNOMnlSMA.tftNGIS TTRCAI..ROHERTHAN AC1U\\l

SPS J..ECE!ll 06/11/18 RCS - REACTO'R COCLIIMT S"YSTI3I Plfl'IGffl)!l'~,._TO L>T.l'IT 'M)S-'dASTE DISPOSAL SYSiB1 Se.Ell l l1lZIJfTB 15 ~ 'WJt.UllPED AND 81.AED llllEN FOOT YllC-"9:lHTLQIJ)QEICVAtl/E nlCIC RE1Nr0RCB)COHCS;Eff CQHtA,H1811' 11At.

Rcvi ion 5 1.05-Updated nlinc 07/30/20 P lJF /\\R 6.2-15

Thefo /lo*wing information is HL TORI 'AL and is not intended or expected to be updated for the life of the plant.

I. Two pr duction line motors were used fo r this test. ne was exposed to a total f 1.5 x 10 8 rad of gamma radiat ion in approx imate ly one month. The other motor wa used ti r the final comparative analysis.

2. Both moto rs wer tested for co il resistance by the Wheatstone bridge method, and fo r insulation r istance by meggering both befi re and after motor vibrati n and rever ing operation.

• * * *

• I with a po taccident solut ion of boric acid and

....-----REPLACE

he recircu containment is maintained wet to pr vide a wat I to reduce the potent ock in g the LH I pumps co nt ainment s ucti V '

( eferen e 9). odium hydroxide and b ri acid and sodium tetrab rate decahydrat i discu sed 6.2.2.2.5 in W AP -7153 (Refer n e I 2) and W AP - 16596 (Reference 13), re pectiv ly.

The stainless tecl manual. globe, gate, and ch ck va lv e s are de igned and bui lt in accordan e w ith the l'equiremcnt o u t lin ed in the motor-operated valve description above

( ction 6.2.2.2.4).

The carbon steel va lv es ar built to confo1*m with U A Bl6.5. The material of const ru ction of th body bo nn et, and disk conform to the requirements of A TM Al 05, rade 11; A 181, rade ll ; orA2 16, r adcW or W h ca rb 11 tel valve pass on l y 11011-radioa t ive gases and we re ubject d to hydrostatic test as utlined in M - P-61 except that the test pres ure was maintained for at least 30 minutes.

6.2.2.2.6 Vent Valve

f igh po int vents have been installed at c ri t ica l points in the suct ion I in es of the charging

( I [H T) pumps, and the di charg lines of the LH I pump where ga ould collect.

6.2.2.2.7 Acc umul ato r heck Valves The pre ure-containing part of the e va lve a emblies are de igned in ace rdance with M S P-66. Parts in c ntact with the operat in g rluid are of auste ni t ic stainless stee l or f quival nt corr s ion-re istant material pr ured to app li cab l A TM or Westinghouse spec ifi cat ions.

Revision 5 LOS-Updated nline 07/30/20 6.2-24

The three com bin ations (Bar A, B, and ) reprc e nt degraded ca e with operat ion of less than the in ta il ed emergency core cooling equ ipm ent. These cases are shown only to pr se nt the capability f individual p rti n of the ystem and to demo n t rate the overa l l margins of the system. The operation of on safety inj ec tion charging pump together with two acc umulators is probably capab l f providing protecti n ove r a con id erab ly greater rang th an sh wn. Howev r the a nalysis ha on ly considered breaks up to th e 8-in ch di a mete r.

Ba t* D, which is the co mbination of the afety equip me nt in Bar and, and which a lso rep re e nts the minimum engi nee re d afeguard ava ilable a utoma tically, provides protect ion as hown ov r the complete range of break s ize up to a nd in c luding the omplet c ir cumfe r ntial fractur e of a r actor coolant pipe.

For the small range of brc al sizes up to 2 in che, a hown in ar A, th e act ion of one afe ty inje t ion c ha rgi ng pump act in g a lone is s uffic ient to maintain nough co re wa ter inve ntory to ens ure cont inu ed c re cooling.

6.2.3.2 Borated Water Injection hemistry During the inj ect ion of eme rgency coo ling water in to th reactor coo lant sy tem fo llowing a LO A, the concentrat ion of b ron will vary depe nding n the dc pre. urizat ion hi to ry of he reactor. If depre s ur izat ion were slow, t he hi gh-head pumps would inj ec t boric acid at a concentration g reater than 23 00 ppm, which would be d.iluted by the c la nt remain in g in t he system. Rapid dep re su ri z ation would bring abo ut ea rly inj ect i n f water co nt a ining o ri c acid at a c nc e ntratio n g reate r than 225 0 ppm from the accumulators. When rec ircul at ion begins, the ave rage concentration of bor ic acid is (and will rem a in) at a concentration that will maintain the core ubcritical.

T he concentrations of ot he r materials, including chlorides are quit low in th is olution co rro sio n products be in g ge nera lly in so lubl e in a basic so lution. Assuming 50% of the ma x imum co re inv entory is re leased to containment after a A the principal fi i n product in the ump (assuming a gro core fa ilure) wou ld be iodine at a ra nge between appr x imate ly 1.6 to 1.9 ppm for 50 0 day f operat ion and appr x im ately 3. 0 to 3.6 ppm for I 000 days of peration. The te mp erature of the s ump water is re du ced below 150°, und er normal operating conditions with a minimum of two recirculation c ole r in operation, after a re lative ly s hort period of t im e i.e. a few h urs). Below 150°F chi rid r l REPLACE ---------

6.2.3.3 h crnica l Additive ontainm nl tra

• onta inm ent sp havin g a pH be tw ee n,,__..._._.,.._.__,.__..,, ill be use......,.,.__,....,...,,_.....,.......,.,__,.__,,...,......, ours if minimum safeguard o pe rate an 50 minute if norm al safeguard o perate. During this peri od, the conta.inment will be coo lin g from 2 80 ° to appr, imately 140°F. At th e nd of the init ia l containment co lin g period, last in g no lo nge r t han appr x imate ly o ne ho ur, the recirculation spray system will continue in se rvice fo r an ind efi ni te pe riod ; however the pH of th e IN S ERT box a n d ita licized text SPS U SAR.-- - --. 6.2 -25 INSER T during th e long-te rm po stacc idenl period RE MOVE re mg spray and furth dition of chem addit iv e is not contemplated.

The followin g information is only ap pli c ab le lo Unit 2.

od ium hydroxide is normally stored for many i ndustria l applications in atmo pheric-vented tanks. Reaction of so dium hydroxide with atmospheric carbon dioxide to form a large precip itate does not occur. However, to e limin ate particulate matter from any p tential source, the containment spray subsy tern includes a, tra in e r on the suction side of the conta inm ent spray pumps. This strainer will have openings sma ll er than the mallest spray nozz les, and therefore wil l remove any particulate matter from the containment spray flow that might prevent the system from functioning.

To illustrate the remoteness of a 0 2 + NaOH reaction, calculations were made based on the following assumpti ns:

J. The tank temperature varies from 35° to 95°F each day, causing the tank to breath

2. All 2 entering the tanl reacts with the caustic.

The ca lculation indicate that this process must continue for 90 years to react with 1 % of the stored caustic. Thi reaction would n t cause a precipitate to form.

Based on past perating experience and ca lculational results, a sod ium carbonate precipitate cannot form; therefore the functloning of the system wi II not be impaired because of precipitation.

The major construction materials that wi ll be exposed to the containment spray and the corros ion or deterioration rates ore ch under maximum exposure conditions, are_........-."?-"l'-,.,_

Tab le 6.2-7. ----- containment ----- --

rial s adversely affected by t pray are aluminum and z in c.

\\....l....>...A..>..A.A.>...>...iV...fY Y'Y'V""V °Y"'lr--t'"<"Y'""'\\ rature expo ' Ure cond ition under which these materials will be exposed to spray are from approximately 50 minute to 1 1/2 hours with the temperature

............,.,...._,.._~~~-.< to 140°..

The materials will also be exposed to the recirculation prays, which have a pH between 7.0 and 9.0 for the po staccident recirculation period with the temperature at approximately 140°F.

The con equence of corrosion and/or deterioration on materials w ith regard to postaccident operation of the engineered safeguards is negli gible because components of the engineered safeguards are con tructed of stainless steel. RE MOV E

The corrosion rate f stainless steel is low enough in the spray olution to be of no practical concern ( Referenc e 1 ).

Insert B

The following iriformalion is only applicable to Unit 1

odium Tetrnborale Decahydrate stored inside containment i a white crystalline chemical in granular form. The NaTB is stored inside ba ket which contain the chemical until it is dissolved by the containment ump water. To eliminate particulate matter from any potential source, the containment spray subsy tern includes a trainer on the suction side of the containment spray pumps. This trainer will have openings smaller than the smallest spray nozzles, and therefore wi II remove any particulate matter from the containment spray flow that m ig ht prevent the system from functioning. Additionally, using NaTB as a buffer doc s not result in any d ifferent precipitates than those that form with the original NaOH buffer and the amount of precipitates is reduced, resulting in lower strainer head lo sses. Therefore, the functioning of the system will not be impaired because of precipitation.

Revision 5 1.05-Updated nline 07/30/20 P UF AR 6.2-49

Table 6.2-7 N TRU T l N MAT ~RJAL XP UR T ONTAINMENT PRAY Material arbon stee l b 0.0 tainless st e l 0.0 onc rete b 0.0 Mineral w o l 0.0 a lcium ilicate and nibestos 0.0 Alumi num 12.0 mg/dm2/hr Zinc (paint and ga lv an izing on teel) 7REPLACE 1 0.04 mg/dm2/hr c opper 0.0 90-10 copper nickel 0.0 P lyethylene and neoprene 0.0 he maximum total durati spray ystem is approxim ate ly 60 minutes.

a. e s than l mil/yr consider d to b zero corrosion rate.

b. Painted with orlar Epoxy hem ical Resi tant Enamel, which is a p lyamide catalyzed epoxy re in _paint.

c. or ro ion rate at 140°, maximum xposure temperatuJe aft r 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. Aluminum has corr s ion rate of le s than 800 mg/dm2/hr at peak temperature.

Revision 51.05-Updated Online 07 /30/20 P UF AR 6.3-1

6.3 ONSEQUENCE-LIMITING AFEGUARD

6.3.1 Spray ystem 6.3.1.1 Design Bases The spray system consists of the co ntainm ent spray subsystem and the recirculation spray subsystem, which are de s igned to provide the necessary coo lin g and depressurization of the containment afte r any LOCA. pray sy tern component data are given in Tab le 6.3-1.

afety related components, piping, valves, and supports in the pray system are Sei s mic ategory J.

The subsystems, operating together, cool and depressurize the containment to ubatmospheric pre sure following the design-basis accident.

The recirculation sub ystem is, in addition, capable of maintaining the subatmospheric pressure in th e containment for an extended period following the design-basis accident.

INSERT he removal of radioactive iodine from the conta inm ent atmosphere after a design-basis accident is accompl ished through the addition of sod ium hydroxide so.lu tion to the containment.-----

r-r.,....,,.....,,...,.,.....,....._ spray (Sect ion 14.5.4). INS ERT

The spray system is designed depres urize the containment to ubatmospheric pressure any one of the two conta inm ent * *

• recircu lati sp ray pump operat in g. tc into the containment 6.3.1.2 Spray System Components on sp ray u bsy s tem

he spray system is designed, fa WM?o-!S't'iWl"---tA~!ti<"M:IT1'-'"!:r1'1'7'M'l'l'M'l:r'l11~f'N",!'91't.:'r;!t-4"K'r.s'"'l'?.rl"h"l'T1'1'1?rll,ri'~-----,,....,..-

of the eneral Design riteria, as discussed in

• ecti n 1.4. The spray subsystems and their components are considered to be essential t acc id ent prevention and/or the mitigation of accident consequences that could affect the public hea lth and safety.

6.3. 1. 2.1 Pumps and Valves The pray pumps and valves are fabricated, welded, and inspected acco1*ding to th e requirements of the app licable portions of the A M ode, ections HJ, VJIT a nd IX. Materials of construction are stain le s steel or equivalent corrosion-res istant materials.

Valve packing and pump seals are selected to m.inimi ze or el imina te leakage where necessary. Motor-operated valve operators are se lected because their proven super ior reliability in past applications ensures reliable valve operation under incident conditions.

The Teflon le eve and packing of the outside recirculation pray system suction va.lves have been changed to XOMOX 7. Th is change reflects the review performed in accordance with NU.. -0578, Section 2. 1.6.b. ln this review.it wa fo und that the valves would be located in a Revision 51.05-Updated Online 07/30/20 PS UFSAR 6.3-2

high-radiation area as a result of a

• CA. The Teflon material is satisfactol'y to only I x 10 4 rads, whereas the XOMOX 7 material is satisfactory to 8 x 106 rads. Th expected 60-year normal plus postacc ident integrated radiation dose in this area is conservatively estimated not to exceed 8 x 106 rads.

REPLACE The containment spray system piping and equipment are fabricated of A M A358, Type 304 stain less steel, or equivalent, which has a corros ion rat of less than 0.0001 in/yr at the

,....,rv-'v-..,.........-il"~!,ffi-,~~ltM..e01~~~~~'c-'rel'"'81iffii~ an 8.7 to 10.4 H. REPLAC E

4. ipment are a lso fabricated f Type 304 or

Type 316L stainless steel, or equivalent, except for the Recirculation pray Heat Exchanger (R HX) tubin i *

• anium and th,......,....,..._,~--.....

• h are brass. stem operating ostaccident 7.0 to 9.0 p (Unit I) and 7.7 to 8.5 pH Unit 2)

-rosion er f austenitic tain. is inhibited i

-...,...;~........ >-..>..>..>...>..,>,..,>,...>,~-

tions in the hypothetical environment after the design-basis

\\--------- - 1REPLACE p a eat a relative ly low pressure of approximate ly 100 psi gauge and a re not highly stre ed during operation, so that the inducement toward cracking is reduced.

ecause t 1e p I of the c nta inment spray elution is a ove. an the recirculation spray solut ion pH is essentia l ly 8.0, the potentia l for caustic stress corrosion cracking in the stem and recircu lation s ra system i " virtua l! nonex i tent.

The p tential for caust ic tress corro ion cracking in the containmen t spray system and recirculation spray system i

• v irtua ll y noncxist nt because of t he fi II wing:

r 1. The short duration of containmen t spray system operation (Un it I) is such that n 2. Th pH of the containment spray so lut ion is above 7.0 (Unit 2)

3. The recirculation spray olution pH i above 7.0 during the I ng-term postaccident Windit period (Unit I and Unit 2) ca lculated to occur un

• er esign-basis acci motors located inside conta inment. REPLACE

The containment motors have been selected to ensure operation during O A conditions.

Motor e lectrical insulati n is in accordance with ANSI, l ~, and NEMA standards. The motors are tested as required by these standards. Bearings are anti friction type. Bearing loading and high-temperature tests have been performed, and the expected bearing life equals, or exceeds, that specified by the Anti Friction Bearing Manufacturers Associat i n (AFBMA).

6.3.1.2.3 P iping Pip ing fabrication, installation, and test ing are in accordance with the peciftcation for P wer P lant Piping, ANSI B31.1, with supplemental requirements and in pect ions as nece sary Revision 51.05-Updated nl.ine 07/30/20 P UFSAR 6.3-4

he suction lines between the containment ump and the R pumps are cross connected.

T his design feature was originally provided to ensure a supply of water to each pump in the event that the sucti on of e ither pump become c lo gged. The current common header st rainers that protect the pump uction lines are designed to withstand the full debris load that could be generated by a LO A.

The design data of the sp ray system components are g iv en in Table 6.3-1.

6.3.1.3 De cription 6.3.1.3.l onta inm ent Spray ystem The containment spray system consists of two completely separate trains of spray rings located in the containmenl dome and one c mmon spray ring located outside the crane wall. Each lrain is rated at 100% capacity. The recirculation spray sy tern is compo ed of two trains, each consisting of an in side recirculation spray ubsystem and an outside recirculation spray sub ystem. ac h subsystem is approximately 50% capacity and consists of one recirculation spray pump, one recircuJation spray heat exchanger (R BX), and one 180° coverage spray header with nozzles. REPLACE

An add it ional ring header common to both containment spray trains is installed at ~ levation 95 ft. 6 in. outside the crane wall. heck valves are installed in each branch connection from the riser to the common header to limit fill time, should on ~~~~~~~~~,'i,J-,~i.,w.,.~~ N"'..,,...,,..-1-v....,...,....,-_

start.. - J b (Unit 2)

The c ntainment spray subsystem is shown i Figur 6.3-I and the recirculation spray s ub system is shown in Figure 6.3-2. levations of al l piping and compon nts of these su bsystems are sho wn in igure 6.3 -4. (Unit 2 only) INSERT---~.

~ ac h of the con mment spray ea ers draws water independen y *01 t e re ueling water storage tank. The odium hydroxide so lution used for iodine rem val fl om the containment atmosphere is

• aed to the containment spray water by a balanced gravity fi ed from the chemical addition tan. he refueling water storage tank is a vertical cy linder with at at bottom and a dome top, and i seemed to a reini reed-concrete foundation. The refueling ater storage tank i fabricated of A TM A240, Type 304L stai nl ss steel, in accordance wi h API TD-650. The requirements fo r welding, we lding procedures, welder qualification, wel point efficiency, and weld inspecti n are in accordance with Section IX of the A ME Code the pecification for Fie ld Fabricated Storage Ta11ks (Reference 4). The chemical addition tank is a vertical cy lindrical vessel wilh flanged and di hed heads mounted on a skirt and secured to the reinforced concrete foundation. The chemical addition tank is fabr icated of A TM A240, Type 304 stai nl ess stee l in accordance with ection VIIl of the A ME Code.

Both tanks are designed as Clas I components, as described in Section 2.5, to withstand design seismic loading in acco rdance with the design tress criteria of A M ~ ode ection Ilf, Fig ure N-414, Nuclear Vessels. The connecting piping is designed to withstand se ism ic loading to Revision 51.05-Updated Online 07/30/20 P UFSAR 6.3-5

ensur the functioning of the system. The refueling water torage tank is provided with a manhole for inspection acce, s.

Prior to unit operation, the wat 1* in the refueling water storage tank is co led to a temperature of sl ight ly below 45 °F by either circu lating the water through a heat exchanger that use chi ll ed water from the chi I led water subsystem of the c mponent cooling system

( ec ti on 9.4 ) o r by using mechanical refrigeration units. M chanica l refrigeration units then maintain the tank water below 45°F. The tank is insulated. The refueling water storage tank also has a.nozz le connection that supp li es water to the safety injection system ( e t ion 6.2).

The refueling water s torage tank (RW T) is a pas ive component and is required on ly during a sh rt period follow in g an accident. It is prov id ed with four channels of level indication, which provide s ignals to level indicators. The leve l indication range for t he RWST is app ro ximately 14,000 ga ll ons at 0% level to approx ima te ly 399,000 gallons at 100% level. The RW Tis maintained at greater than 387 100 gallons of borated water at or below a temperatur of 45°F during normal plant power operations. Level transmitters prnvide input to a low level a larm and an empty a larm when R WST level drops below thes respective sctpo in ts. When two of fou r channels have sensed a low RW T level condition> an interlock signa l is generated to allow for the tart of the TR and ORS pumps on a H.i-Hi Actuation. Additionally, when two of four channe ls have sensed a low-low RW T level condition, a ignal is generated to re align safety injection to the recirculation mode automatica lly. It takes approximate ly three minutes to realign the valves from inj ction to recirculation mode. The I ey values for the RW T as urned in the safety analysis are presented in Ta bl e 5.4-17. The safety analysis values are conservative with respect to plant operation. INS E RT

The chemical addition tank 1s ocatea c se to the refueling water storage tank. The normal perating capac ity of the AT, in c luding in trnment uncertainties, is greater than the minimum CAT volume of 3800 gallons assumed in the safety analysis. F low f the sodium hydroxide so lution is from the chemica l addition tank directly t the containment spray pump suction via a cau tic addit ion line. Th is flow path provides for a red uc ed caust ic tran s it time and introduces the caustic at an e entially constant rate. The c nstant addition rate r,rovides for a more constant spray pH _during the vari u modes of_ afeguard s.system operatio~ IN.S E.RT I

A line from the chemical add1t1on tank c1rculatmg pump 1s installed to permit periodic circulat ion of caustic so lu t ion in the piping and maintain the capability of recirculating the chemical addition tank. IN SERT

The chemica l addition tank: LS msu a e an t e recirculation line i electrically heat traced to keep the tank and recirculation line contents at a temperature wel I above the freez ing point of the chemical sp ray o lu tion. T he chemical addition tank has a I w-temperature alarm set at 35°F.

The containment spray p~1rnp are capable of upplying approx im ate ly 3200 gpm of borated water to two eparate circular containment s pray ring header* located approximately 96 feet above the operating floor in the dome of the containment structure and the common crane wall Revision 51.05-Updated Online 07/30/20 P UF AR 6.3-13

de ermined to be ufficient such that under full debri loading cond it ions there would b adequate N II availab le to the R and Lil I pumps during accident conditions.

6.3. 1.4.2 Recirculation pray Nozzles INSERT

The pray sy t m consi t f two cparate but para II I containment spray ring located in the containment dome and one common containment pray ring located out ide the crane wall, plus£ ur separate but parallel recirculation spray headers each of approximately 50% capa ity.

The use of a cparate spray header c nnected to the di charge of each pump results in a fixed flow rate, and all ws for opt imi zed se lectio n f spray n zz le sizes. Thi arrangement gives the optimum ombination of sma ll pray particles for maximum heat transfer and larg r particles f r better c verage towa rd the center and.ides of the conta inm ent. In addit ion, thi arrangement al o ensure that a failure of a component in any ne sub y tern d es not affect the operational capab ility of the other sub ystems.

The methods of preventing the plugging of pray nozzles in the two systems vary. Fo r each containment sp ray train, the mate *ial of con truction, a well as the pump suction fi lt er, prevent nozzle plugg in g. A method of n zz le testing is provided in the refue ling water storage tank t ensure that no particulate that could plug the containment spray nozzles coll ct in the tank.

espite this precaution and regardles of strain er perforation size, some types of particle cou ld conceivably pass lengthw ise through the strain rand cau e logging of a spray nozzle. lowever, ince the stra in er perforation are maller than th ma ll e t pray nozzle open in g such an occ urre nce is cons.idered to be hi g hly impr bable.

The containment sump stra in er assemb ly i de igned uch that a sing le assembly provide filtered b rated water to a ll fou r y *tern pump, a discus ed in ectio n 6.3. 1.3. The d sign feat ur e of the st rainer p reve nt s complete failu re of a ll suct ion points of the R ystem. Th trainers are rais d off of the floor, which prev nts large d br is (non-buoyant) from reaching the fin and blocking them. Tt provides significant ly large area of fin perforati ns that reduces the approach velocity and possibility of the trainer becoming c mpletely b l eked.

ince t he redundant capacity of the recirculation spray subsystems increase. from 100%

after a I -of-coo lant incident to 400% to 1000% J day after an incident, plugging that co uld on ly occur on a long-term basis w uld have n significant effect n the capability of the ubsy tems.

6.3.1.4.3 Recirculation pray Heat ~xchanger Ini tia lly, the heat exchangers of the recirculation spray trains are c lea n and dry with maximum heat tran fer capab il ity. For long~term operation, on the ord r of week or months, there may be some fouling of the tubes on the servic water side, with resultant los in heat Revision 51.05-Updated Online 07/30/20 PS UF AR 6.3-18

The recirculation pray subsystem n zz les will be subject to an in spection or smoke or air test fo ll owing maintenance or an activity which could cause blockage to prnvide indication that p lu gging of the no zz les has not occu 1Ted. The te ting of system controls is dis ussed in t io n 7. 5.

Electrical in sulation resistance te ts are performed during the li fet im e of the RS motor to verify the integrity of the insulation. Periodic tests are also performed to nsure th motors remain in a reliabl operating condition.

The Recirculation pray y *tern is subject to the applicable inservice inspection and in ervice te s ting requirements fthe A M ode, as required by 10 FR 50 (Code of Federal Regulations, T itl e I 0, Part 50).

6.3 REFEREN ES

1. NR ulletin No. 93-02: Debris Plug g ing of Emergency ore Coo ling uction Strainers, dated May 11, 1993.

2. Letter from Virginia E lectric and Power Company to the NRC, dated June 10, 1993, er ial No. 93 -3 07, Re ponse to NR Bulletin 93-02.

3. etter from Virginia ~ lectric and Power Company to U NR dated February 7, l 996 ( erial N. 95-566A), Generic Letter 95 - 07 Pressure Locking and The,-ma/ Bind in g of Safety-Related Power-Operated Ga te Valves, Surry and North Anna Power Station.

4. tone & Webster pecification NU -258, Specification for Field Fabricated Storage Tanks, Revi ion 2.

5. NR Generic Letter G 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors, dated eptember 13, 2004.

6. Nuclear nergy Institute (NEI) Docum e nt N 1 04-07, Pressurized Water Reactor ump Pe1formance Evaluation Methodology dated ecember 2004.

7. afety Evaluation by the Office of Nuclear Reactor Regulation Related to NRC eneric Letter 2004-02, Nuclear Energy Institu te Guidance Rep ort Pressurized Water Reactor ump Performance Evaluation Methodology.

8. Letter from Dominion Resources Inc. to the NR, dated eptember l, 2005, el'ial No.05-212, Respon e to NR eneric Letter 2004-02.

9. Westinghouse Document WCAP-16406-P, Revision 1, Downstream Wear Evaluation

~Methodology for ontainment Sump creens in Pressur ized Water Reactors.

10. Westinghouse Document W AP-16793-NP, Revision 0, Evaluation ofLong-Term ooling Consider ing Particulate, F ibrou s and hemical Debris in the Recirculating luid.

ADD r nsert I nsert

I l. U.. uclear Regulatory Commission tandard Review Plan UREG- 0800, Chapler 6, Section 6.1. 1, Rev 2, Engineered Safety Features Materials.

12. WCA P-7153, investigation of l,emical Additives for Reactor ontainment Sprays, dated March 1968.

13. W AP-16596-NP Revision 0, Evaluation of Altemati ve Emergency Core Cooling System Buffering Agents, dated July 2006.

Revision 5 I.OS-Updated Online 07/30/20 PS UFSAR 6.3-21

Tab le 6.3 - 1 ( NTINUED)

SPRAY SY T ~M OMPON NT DAT A Chemical Addition Tank (Unit 2 o nly ) 2 REPLACE Number ~...,._,...,.._,,.~-...........'-(

Type INSERT Vertical cylindrical apacity 4311 gal Design pre ure 25 psig Design temperature l50 °F Material 304 esign code A ME Section Vlll Operating pressure Atmospheric Operating temperature Ambient NaOH concentration 17-18 %

hcmical Addition Tank Pump _,.....,..,. ___._.,,.......

Number REPLACE Type Vertical centrifugal Rated f1 w 50 gpm Rated head INSERT 7 ft Theoretical horsepower 0.l hp ea l Mechanical Design pres ure 225 psig Material Pump casing 316 haft AE 4140 Impeller S 316 Recirculation pray ystem trainer Assembly Number l (for both ORS and TR ystems)

Material S 304 Design ode A ME ection IJl, Subsection NF, lass 3 Structural DP 9.0 p id Perforations 0.0625 in. diameter perating Pressure 9.0-59.7 psia Operating Temperature 75-280°F

• luid Flowing Borated water Piping ADD Piping is designed to the Code for Pre sure Piping, AN I B3 l..l.

In se rt Valves Recirculation pray system valves are designed in accordance with AN I B 16.5, Steel Piping Flanges and Flanged Fittings, or AN I B16.34, tee] Butt-We ld ed nd Valves.

Inser t D

Sodium Tetraboratc Decahyd rate Baskets (Unit I o nly)

Number 7 Materia l Basket SS 304 Wheels Dup lex S 2205 Nom inal ize (internal dimens ions) 6 fl X 5 ft X 1.5 ft Operating Pressure 9.0- 59.7 psia Operating Temperatu re 75-280°F Technica l Specification minimum 10760 lbm hemical Grade SQ Granular hemical peciflcation 8 20 3 36.5-38.3%

Equ ivalen t Na284O1* I 0H 2O 99.9-I05.0%

Na 2O 16.2-17. 1%

SO4 ~ 3.0 ppm Cl ~ 0.4 ppm Fe ~ 2.0 ppm Chem ica l Sieve Specification Sta ndard No.

Retained REPLACE

INSERT REPLACE WITH INSERT E co ~ <

en

0

INSlOE REACTOR OUTS IDE REACTOR V'I CONTAlNtlENT CONTAINM.EHT REFUELING \\YATER STORAGE TANK 0 Vo

2-:160° SPRAY HEADERS CHEP~ICAL b ADDITION "u a.

TANK to

~

a.

0 2.

2 - REFUELING WATER 2-RECIRCULATION CHEMICAL ADDITION PUMPS TANK PUMPS

2 - MECHANICAL REFRIGERATION C/.l UNITS FOR TEMPERATURE '"O C/.l c

"Tj

NOTES : >

Fe ;:::,

WLC -WEIGKT LOADED CHECK VALVE

• TO CHECK OPERATION OFWLC

BLEED FLO\\// R'IVST I NSTRUMENTATION SHOWN,oN THIS DRAWlNG IS TYP ICAL RATHER THAN ACTUAL DRAIN AC CONTAIN ENT SPRAYPU PS 0

0

(')

0

(!)

0

(/)

BLEED FLOW

DRAIN 00

REPLAC E I,NSERT EI

IHSJDE REACTOR OUTSIDE REACTOR CONTA IN ENT CONTA! MENT REFUELING WATER

STORAGE TANK

2-360° SPRAY HEADER S I I

l I

I I

I I 2

• MECHANICAL REFRIGERATION U ITS FOR I lcMPERATlJRE I

I NOTES :

~ WLC l WLC--WEJGHT LOADED CHECK VALVE TO CHECK OPERATION OF WLC

BLEED FLOY/ R '/ST INSTRU ENTATION SHOW N ON THIS DRAWING IS TYP1CAL RATHER THAN ACTUAL DRAIN I I

t-----.----vi---WLC I

BLEED FLOW DRAIN 1 I ADD NEW F IGURE 6.3-1b ON NEW PAGE 6.3-26b AFTER FIGURE 6.3-1a

Figure 6.3-1 b UN1T2CO TAINME TSPRAYSUBSYSTEM

INSIDE REACTOR OUTSIDE REACTOR CONTAlNtlSNT CONTAINMENT REFUEUNG IVATER

STORAGE TANK

2

• 360° SPRAY HEADERS CHEMICAL C ADDITION '"O TANK 0.

~

Cll c..

2

• REFUELING WATER 2* RECIRCULAl!ON CHEMICAL ADDITION PU PS TIU-IKPUllPS

2 - M ECHANICAL REPRIGERATION UNITS FOR TEI.IPERAT!JRE

NOTES:

WlC

• VIEIGHT L OADED CHECK VALVE

• TO CHECK OPERA TION OF\\'ILC

BLEED FLOW RV/ST INSTRUMENTATION SHOWN ON THIS DRAWi G ISTYPJCAL RATHER THAN ACTUAL DRAJN 0

0

(')

g WLC 0

Cl}

BLEED FL<:JN

DRAIN Tab le 7.5-2 (CO T UED)

VALVES/DAMPER AC ATED BYE GINEERED SAFEGUARDS SIG ALS [I) 0 Function Override/Bypass ;:;

V, 2-CS-MOV-202A d REPLACE (Actuated (Override or 0

Designation (Valve or 2-CS-M OV -202Bd Valve or Signal bypass condition V, Damper Tag o.) Service Damper (Actuation following b (Similar for Unit 2) (Actua d Valve or Damper Description) Position) Signal) actuation) -0 Cl..

~

1-CS-MOV-l OJA Con pray pump A discharge is olation val e Open CLS-HiHi one.....

~

l-CS-MOV-10 1B a C t spray pump A discharge isolation valve Open CLS-HiHi one C.

0 I -CS-MOV-101C a ont spray pump B discharge isolation valve Open CLS-HiHi one ::s 5 -

1-CS-MOV-IOID a Cont spray pump B discharge isolation valve Open CLS-HiHi one 0 0

l -CS-MOV-102A a Cont spray chem add tank isolation valve Open CLS-Hiffi one -....:i l,.J l-CS-MOV-102B a Cont spray chem add tank isolation valve Open CLS-HiHi one S::

N l -CV-TV-150A Cont vacuum pump B outside cont isolation valve Closed SI 0 l -CV-TV - 150B Cont vac uum pump B outside cont isolation valve C losed SI one l-CV-TV - l50C Cont vac uum pump A outside cont isolation valve C lose d SI l -CV-TV -150D Cont vacuum pump A outside cont jsolation valve C lo sed SI 1-CW-OV-I00A a Circ water condenser outlet isolation valve Closed CLS-HiHi

• one 1-CW-OV-100B a Circ water condenser outlet isolation valve Closed CLS-HiHi

• one I -C W-OV-IO0C a Circ water condenser outlet isolation valve. Closed CLS-HiHi

• one 1-CW-MOV-lO0D a Circ water condenser outlet isolation valve Closed CLS -HiHi

• one 1-C W - OV-106A a Circ water condenser inlet isolation valve Closed CLS-HiHi

• one

a_ These circuits have features that cou ld prevent immediate operation of the component when the engineered safeguards signal is actuated. Such features are a necessary part of the circuit (such as a limit switch), or they require conscious effort by an operator to prevent operation (such as manipulation of a pushbutton or a selector switch ). A valve limit switch could act to delay safeguards - initiated operation if the valve was in mid-travel and had to complete the travel sequence before operating in response to the safeguards signal. A pushbutton or selector switch held in the actuated position gives the operators an option, in some cases, of delaying component response to an emergency safeguards signals.

b. A key-operated switch is under administrative control to prevent inadvertent component operation and to satisfy the requirements ofIEEE Standard 279 - 1971. -....:i c. A mode switch is under administrati e control to re ent inadvertent a(iQnment of this dam er duri V, I

d. Th e va lve tag nu mbe r listed is for Unit 2 beca u se the re is n o equ ivalent v a lv e tag nu mbe r fo r Unit 1. N

I I NSERT I

Table 15.2 - 1 (CO TINUED)

STRUCTURES, SYSTEMS, AND COMPO TS DESIO

• ED FOR SElSMIC AND TORNADO CRITERIA (Refer to the equipment classification list (Q - list) for a more comprehensive list of components. See ote 1.)

Earthquake Tornado 0 Item Criterion Criterion Sponsor 3 ote u,

c. Pressurizer surge line was reanalyzed per NRC Bulletin 88 - 11, dated December 20, 1988. C I

'-a 0.

Systems ( continued) p)

Reactor coolant system (continued) [

Pressurizer safety and relief valves I p w Safety injection system n 0

Accumulators and supports I A w -....l

--... w Low -head safety injection pumps and piping l p w P for containment integrity ~

Boric acid injection tanks and piping I p w 0 Piping, valves, and supports I A SW Except drain/sample lines Containment spray system Refueling water storage tank I A SW Containment spray pumps I A SW Piping, valves, and supports I A SW Except recirculation lines r:r.i "'01 Refueling water chemical addition tank SW C Recirculation spray systems Recirculation spray pumps and piping p SW P for containment integrity Recirculation spray heat exchangers I A SW Reactor containment sump and screens I A SW Piping, valves, and supports I SW

Vt iv I w

Revision 51.05-Updated Online 07/30/20 P UF AR 18-4

• Diesel-driven fire pump fuel oil storage tanks

• Refueling water storage tanks REPLACE

• Emergency condensate storage ta nk s

• Fire Protection/Domestic water storage tanks (re-inspection required during the Period of

~xtended Operation)

• Eme rge nc y serv ice water pump die e l fuel oi l st rage tank

An e ngineering eva lu atio n may determine that the observed condition is accepta bl e or requires repair; or, in t he case of degraded coatings, may direct removal of the coating,

non-destructive examinat ion of the s ub st r ate material, and replacement of the coating.

Re-inspections are dependent upon t he observe d surface cond ition, and the result

• of t hi eng in eering eva lu atio n. For the one-t im e inspections, tank conditions were confirmed to be acceptab le, but t he tire protection/domestic water torage tanks require re-inspection during the Period of Extended Operation. Corrective actions for cond itions that are adverse to quality are performed in accordance with the orrective Acti n ystem. 0 1T ect ive action provides reasonable ass urance that conditions adverse to quality are promptly corrected.

In addition to the one-time in spect ion s of spec ifi ed tanks, a second aspect of Item 1 O Table 18-1 is to eva lu a te the need for ongo in g inspections. The one-time in pection resu lt s for all tank, except the fir e pr tecti.on/domestic water storage tanks, indicated acceptability during t he complete Period of

• xtended perati n (P ). The fire protection/domestic water storage tank will require re-inspect ion during the PEO based on an engineer in g evaluat ion of th~ one-time inspection results.

The combination of acceptable resu lts from the one-t im e in specti n, and the development of plans for future inspection of the fire protection/domestic water storage tan I s, comp letes the task required fo r Item 10 Tab le 18-1.

18.I.4 Non~Environmental Qualification (EQ) Cable Monitodng

T he purpose of the No n-EQ Cab le Monitoring activ ities is to petfi rm in pect ions on a limited, but representative, number or accessible cable j ackets an d connector coverings th at are utilized in non- _, Q app lications (I tem 19 Tab le 18-1 ). In order to confirm that ambient cond it ions are not changin g s ufficiently to lead to age-related degradation of the in-scope cable j acl ets and connector coverings, initial visual in spections for the non-EQ app licat ion insulated p wer cab les, in trumentation cables, and contro l cab les (including low-voltage instrumentation and contro l ca bl es that are ens itiv e to a reduction in in sul at ion resistance) are performed in accordance with a stat ion procedure. Visual in spect io n of the representative samp les of non-Q power,

instrumentation, and contro l cable jackets and connector coverings detect the pre e nce of Serial No. 21-138A Docket Nos. 50-280/281 Enclosure

Attachment 2

PROPOSED SURRY UNITS 1 AND 2 UFSAR UPDATE {FINAL)

Virginia Electric and Power Company (Dominion Energy Virginia)

Surry Power Station Units 1 and 2 Note to As-Builder:

Revision 51.05-Updated Online 07 /30/20 RED changes are associated with REMOVE BLUE changes are associated SPS - UCR -2020 - 009

with this UCR

ubsy s tem.........................

it e

Figure 6. 1-1 Unit 1 Eng in eered afeg uards Systems........................ REMOVE

Figu re 6.1-2 Unit 2 ngineered afeguards ystem...,.....,.......,,.....

F igu re 6.2-'I Safety Injection System.................................... 6.2-55 Fig ure 6.2-2 Protect ion Provided by Various mbinations of Safeguards Components.................................... 6.2-56 Fig ure 6.2-3 Available NP H U -JSI Pump NP I Available Analysis.......... 6.2-57 F ig uJe 6.2-4 ontainment Pressure LHSI Pump NPSH Available Analysis...... 6.2-57 Figure 6.2-5 ontainment emperat ur es LHSJ Pump NP H Avai.lable Analy is.. 6.2-58 Total RSHX Heat Rate LHSI Pump NP H Available Ana ly sis..... 6.2-58 6.3-26 igure 6.3 - 2 nit I Recirculation Spray ubsystem........................ 6.3-27 F igure 6.3-3 Unit 2 Recirculation Spray ubsystem........................ 6.3-28 F igure 6.3-4 Piping and omponents levat io n pray ystems............... 6.3-29 l* igure 6.3-5 Typical - eneral Str uctural and Piping Arrangement Recirculation pray and ow Head afety Injection Systems Outside the Reactor Conta inm ent.............. 6.3-30 F* ig ure 6.3-6 Out ide RS Pump NP HA vailable Ana ly si DEHLG at l 0.3 psia, 25°F W.............................. 6.3-31 Fig ur e 6.3-7 Ouhde R Pump NP HA vailable Analysis DEHLG at 10.3 psia, 25°F SW.............................. 6.3-3 1 F ig ur e 6.3-8 Outside R Pump NP H Available Analysis DEHLG at 10.3 psi a, 25°F W.............................. 6.3-32 F igu re 6.3-9 Outside R Pump NPSH Available Analysis D HLG at 10. 3 psia, 25° W.............................. 6.3-32 Figure 6.3-10 inside R Pump NP Available Ana ly sis DE PS at 10. 1 psia, 70°F W............................... 6.3-33 F igure 6.3-11 In side R Pump NP H Available Analysis D P at 10. l psia, 70 ° W............................... 6.3-33 F ig ure 6.3-12 In s id e R Pump NP H Available Analysis DE P at 10.1 psia, 70 ° W............................... 6.3-34 Figure 6.3-13 In ide R pump NPSH Available Analysis DEP SG at 10.1 sia 70 °

• W............................... 6.3-34 Figure 6.3 - J b Unit 2 ontai system......................... 6.3-26b REMOVE Revision 51.05-Updated Online 07/30/20 P UF AR 6.1 -1

CHAPTER6 ENGINEEREDSAFEGUARDS

6.1 GENERAL DESCRIPTION

Note: A required by the Renewed Operating Licenses for urry Units 1 and 2, issued March 20, 2003, various systems, structures, and components discussed within this chapter are subject to aging management. The programs and activities necessary to manage the aging of these systems, structures, and components are discussed in C h ap te r 18.

The engineered afeguards, t gether with the containment ( ha pt er 5), protect the public and the station in the event of the design-basis accident, as defined in Sections 14.5. 1.2 and 14.5. 5. The engineered safeguards are designed to minimize the accident by performing the fo ll owing three functions:

I. Supply borated water to the reactor coolant system to cool the core, decrease reactivity, limit fuel rod c ladding temperatures, limit the metal-water reaction, and ensure that the core remains intact.

2. Limit the driving potential, including differential pressure and time duration, for leakage out of the containment trncture.

3. Reduce the concentrat ion of airborne fission products available for leakage.

The first function i satisfied by the timely, c nlinuous, a nd adequate supply of borated water to the reactor coo lan t system and the reactor core. The second function is satisfied by the provision of heat sin I s for the condensation of steam released inside the containment, the inherent depressurization of the containment below atmospheric pre sure following the design-basis accident, and means for maintaining the containment at subatmo pheric conditions for an

L------...::---' extended eriod of time. The third function is atisfied b rovidin chemica l additiv (NaOH)

1. A safety inj ection system (

reactor coo lant loops.

2. wo separate low-head safety injection subsystems, either of which provides long-term removal of decay heat from the reactor core.

3. Two eparate ubsystems of the spray system (containment spray and recirculation spray) that operate together to reduce the containment temperature, return the containment pre ure to subatmospheric, and remove heat from the contairunent. The recirculati n spray subsystem maintains the containment subatm pheric and tran fers heat from the containment to the service water system ( ec ti o n 9. 9).

Revision 51.0 5-Updated Online 07/30/20 P UP AR 6.J-2

A compo ite chematic diagrnrn of the engineered safeguards systems is shown in Figu re 6. 1-1 and 6. 1-2 for Units 1 and 2, respectively.

The safety inj ction ystem. provides for the charging of borated water to the reactor coolant sy tern from the accumu lators following a LO A. The three accumulators are self-contained and arc de igncd to supply water as oon a the reactor coolant system pressure drops below 600 psig.

Additional makeup to the reactor coolant system i prov id ed by the charging pumps, operating in the safety injection mode, and the low-head afety injecti n pumps. Both the charging and low-head safety injection pump

• are I cated utside the containment, are driven by an e lectric mot r, are capable of b ing rapidly energized or op rated, and are powered from the emergency power buses. The pumps a lso ensure an adequate supply of borated water for an extended peri d of t im e by recirculating water from the containment sump to the react r co r through two separnte flow paths.

The containment spray subsystem supplies ch illed borated water to the containment immediately following the receipt of t he safeguards initiation signal. Th is ubsystem includes two full-capacity, e lc ctric-m tor-driven containm nt pray pump that are located outside the containment and are. uppl ied with power from the emergency buses. The containment spray pump upply chilled water from the refueling water storage tank to the containment. ither pump is capable of furnishing sufficient spray water to prevent verpr surizing the containment structure A chemica l ad iti n tank I a lanced hydraulica ly wit the re ue ing water storage tank an cl provides a flow of sodium hydroxide so lution to increase the aUcalinity oft e co a* INSERT ------

t f lo

• d' a i e i

The recirculation pray subsystem recirculates water from the containment sumps 1rough REMOVE service-water-cooled recirculation spray heat exchanger to the r c ir culation pray h aders. Tw of the four 50% design capacity motor-driven rec ir culation pray pumps are located outs id e the containment. A ll four of the recirculation sp ray coo lers are located inside the containment and transfer conta inm ent heat t the ervice water system ( ection 9.9).

The conta inm ent spray and recircu.lati n spray subsyste s are capable of reducing the containment pres ure to subatmospher ic in less than 60 minute thus terminating all outleakage t t he environment. This original design criterion was modifie in conjunction with th analy es for implementation of the a lt ernative source term. Tbe modi 1ed crit ria require that, fol lowing the LO A, the containment pressure be less than 1.0 psig ithin 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and less than 0.0 psig within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. The radiological consequence ana ly s is der onstrates acceptab le results provided the contain ment pressure does not exceed 1.0 psig for the

• te rv al from I to 4 ho ur fo l lowing the Design Basis Accident. Beyond 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> containment pre sure is as umed to be Jes than 0.0 psig, terminating leakage from containment. REMOVE INSERT The containment vacuum syst m rem v s ny subsequent ai r inl eakage fter the containment pressure has been reduced to subatmos heric. Because of the inherent low eakage design of the conta inm ent, the use of the vacuum p mps will probably not be required for veral dium Tetra bo rate Deca hy d ra tc (N aT B) is stored in ba ket in id co nt a inm ent to in c rease th e a lka lini ump wate r produ ced during an event which exceeds th e L hi gh-hi gh co nt a inm e nt pressur e ac tu ati on whi c h is rcc irc ul at d by th e r c irc ul at i n p ray s ub ys tem to ensur e effect iv e re m ova l of ra di oac ti ve iod ine _,_.,.._..,,.._,,

REPLACE WITH INSERT A Figure 6.1-2 ;::o 0

EEREDSAFEG en <

0 ::I

V,

0 V,

"O b CL

~

Ct>

0..

0

s

-s*

C'll 0

-..,l Alt t,.)

Unll -

!l'I\\IST 0

~

0

~ ~rl~ T--'

,~ : I ---.____,

I,_,,__,_,, ____ ~,

• -- - -- ~ '--~--~~ "'

Legen<l: l'!Jrs f rom~ S>,np ToWwo i't1 I* Co Note:

RCS* ReaCIDr Coolaru system Wo;,;,adMd-11'1 Too FootlN<k-Concra>I RM;T lnstNmenla 'Son V.O S

• V.'os:e OiSP=Ol ~ ~Mot shatmon!lli>~

V.t.C

• Weight cad Ch e<:lt lhlYe ~ ralher lhan -

Gr.iptur;a: No.esm5 0, v-, I I INSERT A I

~ 11:f.',

~l

~l "" ~I-' ~~::=:;;;;==:ttifu~

---+--~ --~+-..... RV-ST,

LOcer YOS

RVIIST lnstramenta6on ate.:

.snawn en d'lis dnr..ing is typical ra er "1an aciUal.

Gnp ' cs No. CSSU.S Revision 51.OS-Updated Online 07/30/20 P UF AR 6.2-l5

The following information is HJ. TORl 'AL and is not intended or expected to be updated for the Life of the plant.

1. Two production line motors were used for this test. One was expo ed to a total of 1.5 x 10 8 rad of gamma radiation in approximate ly one month. he other motor was used for the final comparative analy is.

2. Both motors were te tcd for coil re ista nc by the Wheatstone bridge method, and for inslilation resistanc by meggering both before and after motor vibration and reversing perations.

The co * * * *

• with a postaccident solution of boric ac* nd REPLACE -----

6.2.2.2.5 T h sta inl ess tee manua go e, gate an c cc<. v 111 accordance with the requirements o utlined in the m to r-o pernt

( clion 6.2.2.2.4).

The carbon steel valve are built t conform with U A B 16.5. The materials of construction of the body, bonnet, and disk conform to the requirements of A TM A I 05, rade 11; A 181, rade Tl; or A2 I 6, rade WCB or W. The carbon steel valve pass only non-radi active gases and were subjected to hydro tatic te ta o utlin d in M - P-61, except that the te t pressure was maintained for at least 30 minutes.

6.2.2.2.6 V nt Valves High point vents have been in talled at cr iti cal points in the suction lines of the charging (HH I) pumps, and the discharge lines of the LH I pumps where gasses cou ld collect.

6.2.2.2.7 Accumulator heel Valves The pre ure-containing parts of these valve assemblies are de igned in ace rdance with M P-66. Parts in contact with the operating fluid are of austenitic stain less steel or of equ iv a lent corrosion-resistant materials procured to applicable A TM or Westinghouse s pecifications.

Revision 5 1.05-Updated nline 07/30/20 PS UF AR 6.2-24

The th ree combinations (Bars A, B, and ) represent degraded cases with operation of les than the installed emergency core cooling equipment. The e cases are shown only to present the capabi lit y of individual portions of the system and to demonstrate the overa ll margins of the system. The ope rat ion of one safety injection charging pump together with two accumulators is probably capab le of provid in g protection over a considerably greater range than shown. However, the analys is has on ly considered breaks up to the 8-inch diameter.

Bar D, which is th comb in at ion of the safety equipment in Bars B and, and which also repr ents the minimum engineered safeguards available automatically, provides protection as shown over the comp lete range of break sizes up to and including the comp lete circumferential fracture of a reactor coolant pipe.

For the sma ll range of break sizes up to 2 inches, a shown in Ba r A the act ion of one safety injection charging pump acting alone i s ufficient to mainta in enough core water inventory to ensure continued core cooling.

6.2.3.2 Borated Water Injection Chemistry During the inj ection of emel'gency coo li ng water into the reactor coo lant system fol low in g a LO A, the concentration of bornn wi ll vary depending on the depressurization hi story of the reactor. Tf depressuri zat ion were s low, the high-head pump would inject boric acid at a concentration greater than 2300 ppm, which would be diluted by the coolant remaining in the system. Rapid depl' suri zat ion would bring about early injection of water containing boric acid at a co nc ent rati on greater than 2250 ppm from the accumulators. Wh en recirculation begin, the average concentration of boric acid is (and wi.11 remain) at a concentration that will maintain the core suberitical.

The concentrations of other materials, including chlorides, are quite low in this so lution, corros ion products being generally insoluble in a basic so luti n. Assuming 50% of the maximum core inventory i released t c ntainment after a LO A, the principal fission product in the sump (assuming a gro score fa ilure) would be iodine at a range between approximately 1.6 to I. ppm for 500 day of operation and approximately 3.0 to 3.6 ppm for 1000 days fop ration. The....-------.

temperature of the sump water is reduced below I 50°F, und r n rmal perating conditions with a REMOVE minimum of two recirculation cooler in operation, after a relatively short period of time...... ~---....

few hour ). Bel w J 50°F, ch lorid t *e l

6.2.3.3 Chemical Additives ontainment tra

• w that.

having a pH between..__~,____,....,,..,,,,, ill be u or approx im ate y 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> if minimum safeguards operate an approx1ma ly 50 minutes if normal safeguards operate. During this period, the containment wi II be cooling from 280°F to approx im ately l 40 °F. At the end of the initial c ntainment cooling period, lasting no longer than approx im ate ly one hour, the recirculation spray system will continue in service for an indefinite period* however, the pH of the INSERT-~ INSERT box and italicized text

recircu l further addition of chemical

• es is not contemp lated.

The following informat ion is only appl i cab l e to Unit 2.

Jn crt B odium hydroxide i l1 nnally stored for many industrial applications in atm spheric-vented tanks. Reaction of sodium hydroxide with atmospheric carbon dioxide to form a large precipitate docs not occur. However, to eliminate particulate matter from any potential source, the containment spray subsystem include, a strainer on the suction side of the containment spray pumps. This strainer will have openings smaller than the smallest spray nozzles, and therefore will remove any particulate matter from the containment spray flow that might prevent the system from functioning.

T illu trate the remoteness of a CO 2 + Na H reaction, calculations were made based n the foll wing as umptions:

I. The tank temperature varies from 35° to 95°F each day, cau ing the tan! t breathe.

2. Al l CO 2 entering the tank react with the cau tic.

The al cu lations indicate that this process must continue for 90 years to react with I% of the stored caustic. This reaction would not cause a precipitate to :B rm.

Ba ed on past operating experience and calculational re ults, as dium carbonat prec1p1tat cannot form; therefore, the functioning of the system will not be impaired because of precipitation.

The major construction materials that will be exposed to the containment spray.......,._..__.,_,,.

___ __._ _ _, and the corms.ion or deterioration rates for each under maximum exposure conditions, are

._____ REPLA C E Table 6.2 -7. ----..... containment

tcrials adversely a pray are aluminum and zinc.

\\...J...>.....A..Jo..J...>...>..A..)......_,-..,..Y"v'h-ve "'Yt --cim~er--,....te..--m~ erature expo ure conditi n under which the e material will be exposed to hemical additiv spray are from approximately 50 minute to 1 1/2 hours, with the temperature 0 to 140°.

The materials will a lso be expo ed t the recirculation sprays, which have a pH between 7.0 and 9.0 fir the po taccident recirculation period with the temperature at approximately 140°F.

The consequence f corro ion and/or deterioration on materials with regard to postaccident operation of the engineered safeguards is negligible because components of the engineered safeguards are constructed of stainless steel. REMOV E

The corr ion rate of stainless steel is low enough in the concern (Reference I).

REMOVE box and italicized text only

Insert B

The.following information is only applicable to Unit J

odium Tctrab rale Decahydrate stored ins ide containment is a white crystall in e chemica l in granu lar form. The Na TB i stored inside baskets which contain the chemica l until it is dissolved by the containment sump water. To eliminate particulate matter from any potential ource the containm nt pray s ub yst m inc lude a train r on the. uction side of the containment spray pumps. This strainer will have openings smaller than the smallest spray nozzles, and therefore wi ll remove any particu late matter from the containment spray flow that might prevent the ystcm from functioning. Add it ionally, using NaTB a a buffer doe not re ult in any different pr cip itates than those that form with the original NaOH buffer and the amount of precipitates is reduced, resulting in lower trainer head losses. Therefore, the functioning of the system will not b impaired because of precipitation.

Revision 5 1.05-Updated Online 07/30/20 P VF AR 6.3-l

6.3 CONSEQUEN E-LIMITING SAFEGUARDS

6.3.1 Spray System 6.3.1.1 Design Bases The spray system con ists of the containment spray subsystem and the recirculation spray subsystem, which are designed to pr vide the necessary cooling and depressurization of the containment after any LOCA. pray system component data are given in Table 6.3-1.

Safety related comp nents, piping, valves, and supports in the spray system are eismic ategory I.

The subsystem, perating together, coo l and deprcssurize the containment to subatmospheric pressure fo llowing the design-basis accident.

The recirculation subsystem is, in addition, capable of maintaining the subatm pheric pressure in the containment for an extended period fo ll owing th design-basis accident. R EMOV E

INSERT The removal of radioactive iodine from the containment atmos here after a design-basis ent INSERT epressurize the containment t subatmospheric pressure

1 1 any one of the two containment pra.,..

...------'---. spray pump operating. dissol.ution of odium tetraborate decahydratc int the containment

---

- 6.3.1.2 pray ystem Components REMOVE sum water which i u ed by the recirculation spray subsystem

( nit I an th The spray system is designed, fa l of the Genera l Design riteria, as 1scusse ubsy terns and their components are considered to be essential to accident prevent1_ n and/or the mitigation of accident consequences that could affect the public health and safety.

6.3.1.2.1 Pumps and Valves The sp ray pumps and valves are fabricated, welded, and inspected according to the requirements of the applicable porti n f the A ME Code, ections llI, Ylll and IX. Materials of construction are sta inl es stee l or equivalent corrosion-resistant mat rials.

Valve packing and pump eals are selected to minimize or e limin ate leakage where necessary. Motor-operated valve operators are se lected because their proven superior reliability in past appl ications ensures r liable valve operation under incident conditions.

The Teflon sl ve and pacl ing of the outside recirculation spray system suction valves have been changed to XOMOX 7. This changer fleets the review performed in accordance with N UR G-0578, Section 2.1.6.. In thi review it was found that the valves would be located in a Revision 5 1.05-Updated Online 07/30/20 P UF AR 6.3-2

high-rad iation area as a res ult of a L A. The efl n material is satisfactory to only I x 10 4 rads, wher as th XOMOX 7 materia l L satisfactory to 8 x 10 6 rads. The expected 60-year normal plus postaccident int eg rated radiation dose in this area is conservatively estima ted not to exceed 8 x 106 rads.

REPLACE T h e conta inm ent spray system piping and equipment a re fabricate d of A TM A358, Type 3 04 sta inl ess steel, o r equivalent, which has a corrosion rate of less than 0.0001 in/yr at the rv-vvv-v-v--A'~am-~~~!~~ t: ~~~~~>!~~.l;_~~~~~ia,...... -e.,...,,lH...... ~~ an 8. 7 to 10.4 H.

4.25 to 4 pment are a lso fabricate ype 304 or

Type 316L stainless steel, o r equ iv alent, exce t fo r the Recirculation pr* xchanger (R HX tubi * * * ** anium a nd th,,......,.....,....,.,,.....,..;-v,,....,_ h are bra operat in g

1s inhibite ypothetica l env iron ment after the design-basis

~---- - -~REPLACE pe a e at a re latively low pressure of approximate ly 100 psi gauge and are not highly stressed during operation, so that the inducement toward cracking is reduced.

eca u e t e p J of the conta inm e nt pray so lu tion is a ove. an the recirculation spray so lu t ion pH is essentially 8.0, the potential for ca ustic stress corrosi n crack in g in the conta inm ents ra s stem and recirc ul ation s ra system is virt ual! nonexjste nt.

I for caust ic tress corrosion cracking in the containment

• ray ystem and spray sy tern is virtually nonexistent because *,....,-..,...,,..,,..... 1g :

I p taccident

REPLACE The contai nm ent motors have been selected to ensure operation during O A conditions.

Motor e lectrica l insulation is in accordance with AN l, I E, and N MA stand ards. he motors REPLACE re tested as required by these standards. Bear ings are ant ifric t ion type. Bearing loading a nd

....._ ____ 1i gh-temperat ure test have been performed, and the expected bearing li fe equa ls, or exceeds, that spec ified by the Anti *riction Bearing Manufacturers Association (AFBMA).

6.3. l.2.3 Pi pin g P ipin g fabricat ion, installation, and testing are in acco rd ance with the pecification for Power Plant Piping, AN I B3 I. l, with s upplementa l requirements and inspections as necessary R vision 51.05-Updated Online 07/30/20 P U* AR 6.3-4

The s uction Lines between the containment s ump and the ORS pumps are cross connected.

T hi s de s ig n feature was orig inally provided to ensure a supply of water to each pump in th e event that the suction of e ither pump become clogged. The current common heade r stra in e rs that pr tect the pump suction lines are designed to with tand the full debris load that co uld be generated by a LOCA.

The design data of the spray system components are given in Table 6.3-1.

6.3. 1.3 Description

6.3.1.3.1 ontainment pray System The co nt a inm e nt spray y te rn cons ists of two completely sepa rate trains of spray rings located in t h c nta inm ent dome and one common spray ring located out ide the crane wall. ach train i rated at l 00% capac ity. The recirculation spray system is co mpo ed f two trains each cons isting of an inside reci rcula tion spray subsystem and a n o ut side recirculation spray subsystem. ach s ub y tern is approx im ate ly 50% capacity, and consists of one recirculation spray pump, one recirculation spray heat exchanger (R HX), and one 180° coverage spray header with nozzles. RE PLACE -----

An add itiona l rin g header common to both containment spray trains is in sta ll ed at E leva tion 95 ft. 6 in. o uts id e the crane wall. Check valves are installed in each branch connect ion from the ri ser to the common header to limit fill time, shou ld on ~~~~.-+><~~~~,>tr~&J,v~...,..., '""'"'.,...,..vv~~

start. Figur 6.3-1 a (Unit 1) and Figure 6.3-1 b (Unit 2)

T he conta inm en t spray s u re 6. nd the recirculation spray subsystem is shown in i,,....,...,...,....,........,..,,....,...""" a l piping and nent of t hese subsystems

.-----_, arc shown in Figure 6. ~--.A.,;-"-1~'-"'-"" IN SERT 1,....----\\.,

• nl,,..R_E _M_O_V_E_,,

REMOVE -Eac s water in water to1. sed for iod ment atm to the con

• the chemica l ad refueling w m and a dom top, an d is secured to a reinforced-conc ret e foundat ion. T he refueli1 torage tank is fabricated of A T M A240, Type 3041 sta inl e s steel, in accordance TD-650. The requirements for welding, welding procedures, welder qualification, wel point efficiency, and weld in spect ion are in accordance with Section IX of the A M, ode the )ecification fo r Fie ld Fabricated torage Ta nk s Reference 4 The chemical add iti on tank is a vertical cy lindrical vessel with f ange and di hed heads mountecl on a kirt a nd secured to the reinfo rc ed concrete foundati n. T he chem ica l add ition tank is fabricated of A TM A240, Type 304 tainless teel in acco rd ance *

• Both tanks a re designed as C lass I component, as described in ection 2.5, to withstand REPLACE design se 1sm1c ss cr it e ri a of A M ode ect ion III, Fig ur e N-414, uc.ear esse s. e connec tm g p1p11 s igned to withstand seismic load*

he refueling water storage tank is designed a a la I component Revi i n 51.05-Updated nline 07/30/20 PS UFSAR 6.3-5

ensure th functioning of the system. The refueling water storage tank is pr vided with a manhole for inspection access.

Pr ior to unit operation, the water in the refueling water storage tank is cooled to a temperature of slightly below 45 °F by either circulating the water through a heat exchanger that uses chilled water from the chil led wat r subsystem f the c mponent cooling system

( cction 9.4) or by u ing mechanical refrigeration units. Mechanical refrigeration units then maintain the tank water be low 45°F. The tan l is insu lated. The refueling water storage tank also has a nozzle connection that supplies water to the safety injection system ( cc t ion 6.2 ).

The refu ling water storage tank (RW ) is a passive component and is required on ly during a short period fo llowing an accident. It is provided with four channe ls f level indication, which provide signals to level indicat r,. The level ind ication range for the RWST is approximately J 4,000 gall ns at 0% leve l to approximately 399,000 gallons at 100% level. The RW Ti maintained at greater than 387, l 00 ga ll ons of borated water at or be low a temperature of 45°F during normal p lant power operations. Leve l transmitters provide input to a low level a larm and an empty a larm when RW T level drops below these respective setpoint. When tw of ti ur channels have sensed a low R WST level condition, an interlock ignal i generated to a ll ow for the start of the IR and OR pumps on a L I-E-Hi Actuat ion. Additional ly, when two of four channe ls have s nse d a low-low R W level condition, a signa l is generated to realign afety injection to the recirculation mode automatically. It takes approximately three minute to r align the va lves from injection to recircu lation mode. The key value fo r th RW T assumed in the safety analysis are presented in Tab le 5.4-17. The safet ana l sis values are conservative with respect to plant operation.

The chemical addition ta nk 1s r storage tan. e normal operating capacity of the AT, including in trument uncertainties, is greater than the minimum AT vo l ume of 3800 gallons assumed in the afcty ana ly is. Flow f the sodium hydrox ide so l ution is from the chemical addition tank directly to the containment pray pump suction v ia a caustic add ition line. This flow path pr vides for a reduced caustic trans it time and introduces the caustic at an es ntially on tant rate. The con tant add ition rate Rrovides for a more constant pray pH during the variou modes of afeguards system operatio INSERT

A line fr m the chemica l addition tank circu lat ing pump is installed to permit periodic c irculation of caustic solution in the pip ing and maintain the capability of recircu lating th chem ical addition tank. IN SER T

The chemica l addition tank 1s msu a e an t e recirculation line is electrically heat traced to keep the tank and recirculation line c ntent at a temperature well above the freezing point of the chemical spray elution. The chem ical add ition tank has a low-temperature a larm set at 35°F.

The containment spray pumps are capab le of upplying approximately 3200 gpm of borated water to two eparate circular containment spray r ing headers located approximately 96 feet above the operat ing floor in the dome of the containment structure and the common crane wall Revision 51.05-Update

The recircu lation sp,_,......,,_.,".....,,_..,._.,,__,~.._,,_,._..,.__....,,_,.,_.,_<<-...._..ection or smoke or air test folJowing maintenance or an activity which cou ld cause bl ckage to prov ide indication that plugging of t he no zz les has not occurred. The test i ng of sys tem contro ls is discussed in ection 7.5.

Electrical insulation resistance tests are performed during th e lifetime f the R motor s to verify the integ rity of the ins ulat ion. Per iodic tests are a lso performed to ensure the motors remain in a relia le perat ing condil ion.

The Recirculation pray ystem is s u bject to the applicable in se rvic inspection and inserv ice testi ng requirement f the A ME ode, as required by 10 FR 50 (Cod e of Federal Regulation, Title 10, Part 50).

6.3 REFERENCES

l. NR Bu ll etin No. 93-02: Deb,.;s Plugging of Emergency Core Coo ling Suction Strainers, dated May 1 1, 1993.

2. Letter from Vi rg inia ~ lectric and Pow e r ompany to the NR, dated J u ne I 0, 1993, er ial No.93-307, Response to NR Bulletin 93-02.

3. Letter from Vir g inia E lectric and Power Company to USNRC dated February 7, 1996 ( erial No. 95-566A), Generic Letter 95-07 Pressure Locki n g and Thermal B;nding of Safety-Related Power - Operated ate Valves, urry and North Anna Power StaUon.

4. tone & Webster pecification NU -25 8 Specijlcation for Field Fabricated Storage Tanks, Rev ision 2.

5. NR Generic etter L 2004-02, PotenUal Impa ct of Debr;s Blockage on Emerg ency Recirculathm During Desi gn Bas;s Acddents al Pressurized Water Reacto rs, dated eptember 13, 2 004.

6. Nuc lear E nergy In st itute (N 1) Document N *J 04 -07, Pressurfaed Water Reactor ump Pe,formance Eval uation Methodology, dated December 2 004.

7. afety Evaluation by the Office of Nuclear Reactor Reg u lation Re lated to NR eneric Letter 2 004-02, Nuclear E nergy In *titule uidance Report Pressw*;zed Water Reactor ump Pe,formance E valuation Methodology.

8. Letter from Dominion Resources Inc. to th e NR C dated

• eptembe r 1, 2 005, eriaJ No. 05-21 2, Response to NRC Ge ner;c Letter 2004- 02.

9. We st inghouse Document WCAP-16406-P, Revision 1, Downstream Wear Eva luation Methodology for Co ntainment Sump Screens in Pressurized Water Reac tors.

10. Westin ghous e Document W AP - 16793 -N P, Revi s ion 0, Evaluation of Long-Term Cooling onsidering Particulate, ibrous and Che mical Debris in th e Rec irculating Fluid.

ADD Insert C I n ert C

---

l l. U.. Nu c lear R eg ul a tory omm 1ss1on tandarcl Revi ew Plan NUREG-0800, ha pter 6 ec tion 6. 1. 1 Rev 2, E ng in eer ed Saf ety F eatur es Mat erial s.

WCAP-7 153, lnv estig at; on of 'h emi cal Additives f or Reac t or 1968.

WCAP-16 596 -NP, Revision 0, E valuati on of Alt em a th 1e Em er ge ncy Agents, dated Ju ly 2006.

Revision 51.05-Updated nline 07/30/20 SP UFSAR 6.3-2.1

Table 6.3-1 (CONTINU D)

DATA

Number REPLACE ype INSERT Vertica l cylindrical Capacity 4311 ga l Design pressure 25 psig Design temperature 150°F Material ss 304 Design code ASME ection Ylll R EMOV E Operating pressure Atm spheric Operating temperature Amb ient Na H concentration 17-18%

hemical Addition Tank Pump,__,,.__..-Jo~~- REPLACE Number Type Rated fl w 50 gpm Rated head INSERT 7 ft Theoretical horsepower 0.1 hp Sea l Mechan ica l Design pres ure 225 ps ig Material Pump cas ing Shaft

trainer Assembly 1 (for both OR and IR y ste ms)

Material 304 Design ode A ME Section III, Subsection NF, Class 3 trnctura l DP 9.0 psid Perforations 0.0625 in. diameter Operating Pressure 9.0-59.7 p ia Operating Temperature 75 -2 80° Fluid Flowing Borated water Pip ing ADD Piping is designed to the ode fo r Pressure Piping, AN I 31. 1.

In se rt D Va lves Recirculation Spray system va lves are designed in accordance with AN I B 16.5, tee I Piping F langes and Flanged Fittings, or AN J B 16.34, tee! Butt-We lded End Va l.ves.

I nsert D REMOVE

odium Tetraborate Decahydrate Baskets......._.,._,.,,_..,.__.....,,

Number Material REPLACE Basket 304 Wheels Duplex 2205 Nominal size (internal dimen ion ) 6 ft X 5 ft X 1.5 ft Operating Pres ure 9.0-59.7 psia Operating Temperature 75 - 280 °F Technica l pecification minimum 10760 lbm INSERT hem ica l Grade SQ Granular hemical pecification B2 3 36.5-38.3%

Equiva lent Na2B~O r 1 0H 2O 99.9-105.0%

Na2O 16.2-17. 1 %

04 S 3.0 ppm I :::: 0.4 ppm Fe S 2.0 ppm hemica l ieve pecification tandard No. 8 Retained ::: 0.1 %

REPLAC E REPLACE

INSERT REPLACE WITH I NSERT E

REMOVE co BSYSTEM

INSIDE REACTOR OUTSIDE REACTOR CONTAINMENT CONTAIN ENT REFUELING WATER STORAGE TANK 0 V,

2-360° SPRA\\'HEAOBIS I I CtlEIAlCAL ADDITION TANK

i

i 0

0 I -.....)

v.l I -

2* RECIRCULATION ~

PUMPS 0 I

l I 2

• I.IEOHAJI ICAL REFRIGERA TION (/J UNITS FOR I TEMPERATUR 'E "'d

(/J I ~

AC (/J I :::0

WLC -WEIGHT LOADED CHECK VAi.VE

• TO CHECKOPERATIOtl ' OFW LC l RWST INSTRUMEITTATIO SHOWN ON TH IS BLEED FLOW DRAWING IS TYP I CAL RATHERTHAH ACTW<L

DRAIN 0

0 C')

0

<D 0

rn

BLEED A.OW DRAIN ADD NEW F IGURE 6.3-1b I REMOVE FIGURE AND PAGE ~ ON NEW PAGE AFTER FIGURE 6.3-1 a

Figure 6.3 - lb UNIT 2 CO T AlNME T SPRAY SUBSYSTEM

INSIDE REAC TOR OUTS IDE REACTOR CONTAJNM ENT CONTAINMENT REF U Ei. G WATER STORAGE TANK

2-360 ° SPRAY HEADERS CHEM I CAi..

ADDITIO TANK

2-RECIRC UL ATION PUl,IPS

2

• MECHANICAL REFR IGERATION U NITS FOR en TElolPERATIJRE "'O en

NOTES :

Wl.C - WEJGHT LOADED CHECXVA LVE

• TO CHECKOPERATIONOFWLC

BLEED FLOW R\\VST I NSTRUMENTATION SHOWH O THIS DRAW G ISTVPICAI.. RATHER THAN ACTUAL.

DRAIII CONTAINMENT 0 SPRAY PUMPS 0

0

<O WLC 0

(/)

Bl.EEO FL OW 0\\

DRAIN w I

N 0\\

0-Table 7.5 -2 (CO TINUED) ~

VALVES/DAMPERS ACTUATED BY ENGINEERED SAFEGUARDS SIG ALS <

Vl 0

Function Override/Bypass ::;

V, 2-CS-MO V-202A ct REPLACE (Actuated (Override or -

0 Designation (Valve or 2-CS-MOV - 2028 d Valve or Signal bypass condition V, Damper Tag Io.) Service Damper (Actuation following C I (Similar for nit 2) (Actua d Valve or Damper Description) Position) Signal) actuation) -0 C.

Con pray pump A discharge isolation valve Open CLS -HiHi one ~

C.

C t spray pump A discharge isolation valve Open CLS -HiHi one um B discharge isolation va lve CLS -HiHi one 0

s CLS -HiHi one 0 0

-....)

Open CLS-HiHi one w em add tank isolation valve Open CLS-HiHi one i5 1-CV-TV-150A Cont vacuum pump B outside cont isolation valve Closed Sl one 0 l -CV-TV-150B Cont vacuum pump B outside cont isolation valve Closed SI one l -CV-TV-150C Cont vacuum pump A outside cont isolation valve Closed SI one 1-CV-TV-150D Cont vacuum pump A outside cont isolation valve Closed SJ one 1-CW -MOV-l00A a Circ water condenser outlet isolation valve Closed CLS-HiHi

• one Cl) 1-CW-MOV-l00B a Circ water condenser outlet isolation valve Closed CLS-HiHi

• one ""O Cl) 1-C -MOV - l00C a Circ water condenser outlet isolation valve Closed CLS-HiHi

• one C "Tl l-CW-MOV - 100D a Circ water condenser outlet isolation valve Closed CLS-HiHi

• one Cl) l -C\\.V-MOV - 106A a Circ water condenser inlet isolation alve Closed CLS-HiHi

• one ~

a. These circuits have features that could prevent immediate operation of the component when the engineered safeguards signal is actuated. Such features are a necessary part of the circuit (such as a limit switch), or they req_uire conscious effort by an operator to prevent operation (such as manipulation of a pushbutton or a selector switch). A valve limit switch could act to delay safeguards-initiated operation if the valve was in mid - travel and had to complete the travel sequence before operating in response to the safeguards signal. A pushbutton or selector switch held in the actuated position gives the operators an option, in some cases, of delaying component response to an emergency safeguards signals.

b. A key-operated switch is under administrative control to prevent inadvertent component operation and to satisfy the requirements of IEEE Standard 279 - 1971. ---.l

c. A mode switch is under administrative control to revent inadvertent aliQllment of this dam er duri U'l I

tv d. The v a lve tag number listed is for Unit 2 because there is no equivalent va lve tag number for Un it 1.......

IN SER T

REMOVE Table 15.2-1 (CO ED)

STRUCTURES SYSTEMS, ND COMPO DESIO D FOR SEISMIC AND TORNADO CRITERIA (Refer to the equipment classification list (Q-list) for a more comprehensive 1 ist of components. See ote 1.)

Earthquake Tornado Item Criterion Criterion Sponso r-'1 ote

c. Pressurizer surge line was reanalyzed per C Bulletin 88-11, dated December 20, 1988.

Systems ( continued)

Reactor coolant system ( continued)

Pressurizer safety and relief valves I p w

J Safety injection system Cl)

Accumulators and supports I IA w ---l 0 w

Low-head safety injection pumps and piping I p w P for containment integrity 0

~

Boric acid injection tanks and piping I p w 0

Piping, val es, and supports I A SW Except drain/sample lines Containment spray system Refueling water storage tank I ; A SW Containment spray pumps I A Except recirculation lines dditio Recirculation spray systems Recircula tion spray pumps and piping SW P for containment integrity Recirculation spray heat exchangers I ' A SW Reactor containment sump and screens I TA SW Piping, valves, and supports I A SW REMOVE

VI

..... N I

v.)

Revision 51.05-Updated Online 07 /30/20 PS UFSAR

• Diesel-driven fire pump fuel oil torage t an ks

• Refueling water storage tanks

• 2 n ly) REPLACE

• REMOV E

• F ire Protection/Domestic water storage tanks (re-i nspect ion req uLred during the Period of Extende d Op eration)

• Emergency serv ice water pump di ese l fue l oil storage tank

An eng in eer in g evaluation may determ in e that t he observed cond ition is acceptable or req uir es repa ir ; or, in t he case of d egrade d coatings, may direct re moval of the coating, non-destructive exam ination of th e s L1b strate material and replacement of the coating.

Re-inspections are dependent upon the o bse rv ed ur face con dit i n, an d th e resu lts of this engineering eva lu ati on. Fo r the one-t im e in specti n, ta nk co nditi o ns were confirmed to b acceptable, but th e fire protection/domestic water storage tanks req uire re-in spectio n during the Pe riod of Exte nd ed Operation. orrective actio ns for conditions that are a dv erse to quality are performed in accordance with the orrective Action System. orrective action provides reaso nabl e assurance that condition adve rse to quality are pr rnptly corrected.

In addition to th e one-time inspec tion s of spec ifi ed tank s, a seco nd aspect of Item 10,

Tabl 18-1 is to evaluate the ne ed for ongo in g in spect ions. T he one-t im e in s pec tion resu lt fol: a ll tank, exce pt the fire protect ion/domestic water storage tanks, indicated acceptability durin g the complete Per iod of xtended Operation (PEO). T he fire protection/domestic water storage tank will require re-inspection during the P O ba sed o n an eng in ee rin g eva lu atio n of the o n -ti m e in spec tion results.

The comb in ation of acce ptable resu lt s from the one-time inspections, a nd the deve lopment of p la ns fo r future in spect ion of th e fire pr tection/dome tic water torage tank, comp letes the ta s ks req uired for Item l O Table 18 - 1.

18.1.4 Non-Environmenta l Qualification (EQ) able Moni toring

T he purpose of the Non-EQ Cab le Monitorin g activit ies is to p erfor m in spectio ns on a limited, but re presen ta tive, numb er or access ibl cab! jacl ets a nd connector covel'ings that a re utilize d in non-Q a pplicat i n ( Item 19, Tab le I 8-1 ). ln order to co nfirm that ambient conditions are not changing s uffic iently to lead to age-re lated degra dation of th e in-scope cable j ackets and connector coverings, initial vi s ual in spectio ns for the non - Q application in ulated power cables, instrumentation cab les, and control cables (in cl udin g low-vo ltage in st rument at ion and control cable tha t are se n iti ve to a red uct ion in insulation res ista nce) are performed in accordance with a stat ion proc ed ur e. Vi s u a l in spectio n of th e rep r esentative sa mpl es of non-Q power, instrumentation, and contro l cable jackets and connector cover in g detect the presence of