Text

E-mail Gucwa, Entergy Nuclear Northeast, to Ennis, NRR, VY EPU Supplement 30
	ML052220446
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	08/02/2005
From:	Gucwa L; Entergy Nuclear Northeast
To:	Richard Ennis; Office of Nuclear Reactor Regulation
References
	BVY 05-072
	Download: ML052220446 (1)
	v • d • e

Rick Ennis - BVY 05-072 Exhibits SPSB-C-52-1 and 2 PTage 11 From:

"Gucwa, Len" <LGUCW90@entergy.com>

To:

"Rick Ennis" <RXE@nrc.gov>

Date:

8/2/05 2:12PM

Subject:

BVY 05-072 Exhibits SPSB-C-52-1 and 2

<<BVY 05-072 Ex. SPSB-C-52-2.pdf>> <<BVY 05-072 Ex. SPSB-C-52-1.pdf>>

Len T. Gucwa, P.E.

VY Licensing Igucw90@entergy.com 802/451-3193 CC:

<Douglas. Rosinski@pillsburylaw.com>

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BVY 05-072 Exhibits SPSB-C-52-1 and 2 8/2/05 2:10PM "Gucwa, Len" <LGUCW90entergy.com>

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BVY 05-072 Docket No. 50-271 Exhibit SPSB-C-52-1 Vermont Yankee Nuclear Power Station

Proposed Technical Specification Change No. 263 - Supplement No. 30 Extended Power Uprate Response to Request for Additional Information Calculation VYC-0886, Rev. 2 Total number of pages in this Exhibit (excludina this cover sheet) is 13.

VY CALCULATION CHANGE NOTICE (CCN)

CCN Number:

04 Calculation Number:

VYC-0886 Calculation

Title:

Station Blackout Documentation Analysis Initiating Document:

EPU Rev. No.

2 VYDCIMMiTMISpec. NoJ other Safety Evaluation Number:

N/A Superseded Calculation:.

N/A Superceded by.

N/A Implementation Required: 0 Yes El No Computer Codes: N/A Reason for Change:

The VYC-0886 Rev 2 is updated to assess the effect of Extended Power Uprate (EPU) on this calculation.

Description of Change:

This CCN updates VYC-886 Rev 2, for EPU.

Technical Justification for Change:

See Attachment A

==

Conclusions:==

The results of Reference 1 were addressed at EPU conditions. The effect of EPU on VYC-886Rev2 are summarized in Attachment A.

Are there any open items in this CCN? Z Yes El No Prepared By/Date J Interdiscipline Review By/Date Independent Review By/Date Approved By/Date I

/9 fr 120~CMC,

~_2e1_1 c

Alan L. Robertshaw James G. Rogers Final Turnover to DCC (Section 2):

1) 2)

All open items, if any, have been closed.

Implementation Confirmation (Section 2.3.4)

E Calculation accurately reflects existing plant configuration, (confirmation method indicated below)

El Walkdown El As-Build input review Dl Discussion with OR 0 N/A, calculation does not reflect existing plant configuration (print name)

3) Resolution of documents identified in the Design Output Documents Section of VYAPF 0017.07 has been initiated as required (Section 2.3.6, 2.3.7)1

/

Print Name Signature Date Total number of pages in package including all attachments-13 pages Note: VYAPF 0017.07 should be included immediately following this form.

VYAPF 0017.08 AP 0017 Rev. 8 Pa-I _f I

VY CALCULATION DATABASE INPUT FORM Place this form in the calculation package immediately following the Title page or CCN form.

VYC-0886/CCN04 2

N/A N/A VY Calculation/CCN Number Revision Number Vendor Calculation Number Revision Number Vendor Name:

N/A P0 Number:

NIA Originating Department: Design Engineering Critical References Impacted: E UFSAR & DBD E Reload. "Check' the appropriate box if any critical document is identified in the tables below.

EMPAC AssetlEquipment ID Number(s): N/A EMPAC Asset/System ID Number(s): N/A Keywords: Decay Heat. SBO. Torus Temperature. Condensate Storage Tank. Ventilation For Revision/CCN only: Are deletions to General References, Design Input Documents or Design Output Documents required? L Yest O No Design Input Documents and General References - The following documents provide design input or supporting information to this calculation. (Refer to Appendix A, sections 3.2.7 and section 4)

Significant Critical Difference Affected Reference

Reference #

- DOC #

REV

- - Document Title (including Date, if applicable)

Review tt Program

(/)

1 VYC-0886 2

Station Blackout Documentation Analysis, 01/03/2001 2

TE 2003-064 Station Blackout PUSAR Input 3

GE-VYNPS-N/A Letter, Michael Dick (GE) to Craig Nichols (ENOI), VYNPS EPIJ Task T0400: Decay Heat AEP-146 for Containment Analysis dated March 10,2003.

4 VYC-2282 0

Vessel Stored Energy with GE14 Fuel at 20% Power Uprate, dated 5/9/03 5

NUMARC 87-N/A NUMARC 87-00, dated 11120/87, Including NRC accepted errata and Q & ANs from 00 MUMARC seminars and Topical Report F.

6 NVW 91-98 N/A Letter, USNRC to VYNPC, NW 91-98, Vermont Yankee Station Blackout Analysis,"

June 5, 1991 7

N/A ASME Steam Tables 8

NIA VY Technical Spocification 9

VYC-2270 0

1W GE 14 Appendix R at 20% Power Uprate, dated 05/09/2003 10 VYC-415 0

Appendix R/RCIC, HPCI & ECCS Room Cooling, dated 4/29/1986 11 VYC-415 0

Appendix RIRCIC, HPCI & ECCS Room Cooling, dated 9/0412002 CCN 01 VYAPF0017.07 AP 0017 Rev. 8 Page 1 of 4

Significant Critical Difference Affected Reference

Reference #

DOC #

REV

***Document Title (including Date, if applicable)

Review tt Program

(/)

12 VYC-886 2

Station Blackout Documentation Analysis, dated 9/04/2002 CCN3 13 VYC-2279 0

Evaluation of EPU Impact on Ambient Space Temperatures During Normal Operation, dated 04/11/2003 14 VYC-1347 0

Main Steam Tunnel Heatup Calculation, dated 1111196 is OT-3122 19 Loss of Normal Power, 04/18100 16 VYC-1628D 0

Torus Temperature Response to Appendix R and Station Blackout Scenarios, dated CCN02 VYC-0886 Rev 2 CCN04, Page 3 of 7 VYAPF0017.07 AP 0017 Rev. 8 Page 2 of 4

VY CALCULATION DATABASE INPUT FORM (Continued)

Design Output Documents - This calculation provides output to the following documents. (Refer to Appendix A, section 5) tttCritical

- - e Affected Reference Reference DOC REV Document Title (including Date, if applicable)

Program (1)

VYC-1432 4

VY Vessel Level for Appendix R, 05/17/1996 VYC-1458 0

Station Blackout Load Capacity Analysis. 10/15/1996 VYC-1628 0

Torus Temperature and Pressure Response to Large Break LOCA and MSLB Accident CCN3 Scenarios, 3/21/2002 VYC-1628D 0

Torus Temperature Response to Appendix R and Station Blackout Scenarios-dated November 5, 1998.

VYC-2159 0

VY-Cycle Independent Decay Heat-Comparison Between ORIGEN-2 and ANSI/ANS 5.1-1979 Standard, 2/27/2001 VYC-2314 0

Minimum Containment Overpressure for Non-LOCA Events, 9/03/2003 DBDSADBD DBD

/

DBD CPS DBD V

DBD HPCI DBD DBD HVAC DBD DBD MS DBD DBD NBVI DBD

/

DBD RCIC DBD DBD RIIR DBD SSCA Vol 1 Appendix R V

VYC-0886 Rev 2 CCN04, Page 4 of 7 VYAPF0017.07 AP 0017 Rev. 8 Page 3 of 4 LPC#6

VY CALCULATION DATABASE INPUT FORM (Continued)

Reference # -

- Doc f -

- - Document Title -

- - - Affected Program -

Assigned by preparer to identify the reference in the body of the calculation.

Identifying number on the document, if any (e.g., 5920-0264, G191172, VYC-1286)

List the specific documentation in this column. "See attached list" is not acceptable. Design Input/Output Documents should identify the specific design input document used in the calculation or the specific document affected by the calculation and not simply reference the document (e.g., VYDC, MM) that the calculation was written to support.

List the affected program or the program that reference is related to or part of.

t If "yes," attach a copy of "VY Calculation Data" marked-up to reflect deletion (See Section 3.1.8 for Revision and 5.2.3.18 for CCNs).

tt If the listed input is a calculation listed in the calculation database that is not a calculation of record (see definition), place a check mark in this space to indicate completion of the required significant difference review. (see Appendix A, section 4.1.4.4.3). Otherwise, enter "N/A."

fft If the reference is UPSAR, DBD or Reload (IASD or OPL), check Critical Reference column and check UFSAR, DBD or Reload, as appropriate, on this form (above).

Note: All calculations in the Design Output list were reviewed. No revision required.

Other Design Output were reviewed. The following revisions are required:

1) DBDs referencing VYC-886 Rev2 need to be addressed.

2) Calculation VYC-1347 should be addressed for EPU.

VYC-0886 Rev 2 CCN04, Page 5 of 7 VYAPF0017.07 AP 0017 Rev. 8 Page 4 of 4 LPC#6

Page 6

of 15 VY CALCULATION REVIEW FORM Calculation Number:

VYC-0886 Revision Number:

2 CCN Number:

04 Titl:

Station Blankout DoncimAntation AnAlvqis, 1-1-----

DP I;P4-F-Acr;-A.

A fN-Dah1-tchn-Required Date: FebruarZ 2004 1A%,V IL, i CI 4-Larlt;U, CIIAI IXUUt LLa31 El Interdiscipline Review 3 Independent Review Comments*

1. Assurntions on page 1 of Att. A need Reference, Resolution

l. Added

-

r-as Of'

2. Need Reference for Table 1 in Att. A.

2. Done

3. On page 5 of Att. A please state the TS CST Inventory.

3. Added TS CST invento 629~i~

--2(

f-&,L PJ1. -A, IM 9A

,--.Door(

0QL.

Date L

G n

Reviewer Signature Date 7 Calculation Preparer (Cornments Resolved)

/-

Method of Review:

Z Calculation/Analysis Review O Alternative Calculation

_I__

_/

K I Qualification Testing Reviewer Signature (Comments Resolved)

Date

Comments shall be specific, not general. Do not list questions or suggestions unless suggesting wording to ensure the correct interpretation of issues.

Questions should be asked of the preparer directly.

VYC-0886 Rcv 2 CCN04, Page 6 of 7 VYAPF0017.04 AP 0017 Rev. 8 Page 1 of I

Calculation VYC-0886 Rev2 CCN04 page 7 of 13 Page -

7 --of 7

Calculation Number:

VYC-886 Open Item VY CALCULATION OPEN ITEM LIST Revision Number:

2 Resolution CCN Number:

4 Method of 01 Tracking or Date Closed DBDs referencing VYC-886 Rev2 need to

-be verified for changes to torus temperatures.

VYC-1347 needs to be CCN for EPU

,i VYC-0886 Rev 2 CCN04, Page 7 of 7 VYAPFOOI7.05 AP 0017 Rev. 8 Page 1 of 1

Calculation VYC-0886 Rev 2 CCN 04 Page 1 of 6 Attachment A Reason for Revision Revision 2 of VYC-0886 is updated to incorporate the EPU changes This CCN incorporates:

1) Condensate Inventory Requirements at EPU incorporating:

- The decay heat at EPU from Reference 3.

- Vessel stored energy at EPU from Reference 4 (VYC-2282).

2) Loss of ventilation

3) Torus Temperature Assumptions (same as in reference 1)

1. No off-site power available (SBO)

2. The reactor depressurizes from 1095 psia to 100 psia during the SBO scenario. The 1095 psia is assumed to be an average SRV setpoint. The 100 psia is assumed a low pressure setpoint where RHR system is deployed for shutdown cooling.

3. It is assumed that at about 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months , the vessel pressure decreased to about 100 psia.

4. It is assumed that at 100 psia the fluid and solids in the reactor vessel are at the same temperature.

This is a reasonable assumption, since at 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months , most of the metal in the vessel will be at the fluid saturation temperature.

Condensate Inventory Requirements The inventory required for decay heat removal will be calculated using a formula given in NUMARC 87-00 and also using the decay heat calculated in Reference 3.

Condensate Inventory to Remove Decay Heat From Reference 5 V = 35.55 gal/MWt = 35.55

1912

1.02 = 69331 gallons for 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months From the decay heat calculation Q decay at 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months (interpolated in the integrated decay heat table - Table 1, Reference 3, next page) 20000 4.68951E+08 28800 6.11079E+08 40000 7.91978E+08

Calculation VYC-0886 Rev 2 CCN 04 Page 2 of 6 Attachment A Table 1 - Integrated Decay Heat for 20% power Uprate Time (sec) 0.00000 0.10000 0.15000 0.20000 0.40000 0.60000 0.80000 1.00000 2.00000 4.00000 10.00000 20.00000 40.00000 60.00000 80.00000 100.00000 150.00000 200.00000 400.00000 600.00000 800.00000 1000.00000 1500.00000 2000.00000 4000.00000 6000.00000 8000.00000 10000.00000 15000.00000 20000.00000 40000.00000 60000.00000 80000.00000 86400.00000 100000.00000 150000.00000 172800.00000 200000.00000 259200.00000 345600.00000 400000.00000 432000.00000 600000.00000 800000.00000 864000.00000 1000000.00000 GE 2 sigma P/Po 1.00000 0.99210 0.96250 0.93280 0.74710 0.59080 0.49380 0.33880 0.15480 0.06073 0.05234 0.04546 0.03986 0.03687 0.03466 0.03321 0.03073 0.02909 0.02550 0.02346 0.02197 0.02079 0.01861 0.01707 0.01370 0.01209 0.01114 0.01047 0.00986 0.00918 0.00775 0.00699 0.00647 0.00633 0.00608 0.00539 0.00515 0.00492 0.00451 0.00406 0.00384 0.00373 0.00327 0.00290 0.00281 0.00265 Integrated 0.00000 0.09961 0.14847 0.19585 0.36384 0.49763 0.60609 0.68935 0.93615 1.15168 1.49089 1.97989 2.83309 3.60039 4.31569 4.99439 6.59289 8.08839 13.54739 18.44339 22.98639 27.26239 37.11239 46.03239 76.80239 102.59239 125.82239 147.43239 198.25739 245.86739 415.22739 562.63739 697.19739 738.15099 822.54579 1109.27079 1229.46099 1366.41299 1645.27459 2015.28259 2230.16259 2351.26659 2939.18259 3556.48259 3739.39459 4110.81059 Integrated Kwsec 0.00000 1.94254E+05 2.89552E+05 3.81959E+05 7.09580E+05 9.70503E+05 1.18203E+06 1.34440E+06 1.82572E+06 2.24606E+06 2.90760E+06 3.86127E+06 5.52521E+06 7.02163E+06 8.41664E+06 9.74026E+06 1.28577E+07 1.57743E+07 2.64207E+07 3.59690E+07 4.48290E+07 5.31682E+07 7.2378 1E+07 8.97742E+07 1.49783E+08 2.00080E+08 2.45384E+08 2.87529E+08 3.86649E+08 4.79500E+08 8.09793E+08 1.09728E+09 1.35970E+09 1.43957E+09 1.60416E+09 2.16334E+09 2.39774E+09 2.66483E+09 3.20868E+09 3.93028E+09 4.34935E+09 4.58553E+09 5.7321 1E+09 6.93599E+09 7.29272E+09 8.01707E+09 Integrated, BTU 0.00000 1.89980E+05 2.83182E+05 3.73556E+05 6.93969E+05 9.49152E+05 1.15602E+06 1.31483E+06 1.78556E+06 2.19664E+06 2.84363E+06 3.77632E+06 5.40366E+06 6.86715E+06 8.23147E+06 9.52598E+06 1.25749E+07 1.54273E+07 2.58394E+07 3.51777E+07 4.38427E+07 5.19985E+07 7.07858E+07 8.77992E+07 1.46488E+08 1.95678E+08 2.39985E+08 2.81203E+08 3.78143E+08 4.68951E+08 7.91978E+08 1.07314E+09 1.32979E+09 1.40790E+09 1.56887E+09 2.11575E+09 2.34499E+09 2.60621E+09 3.13809E+09 3.84382E+09 4.25367E+09 4.48465E+09 5.60601E+09 6.78340E+09 7.13228E+09 7.84069E+09

Calculation VYC-0886 Rev 2 CCN 04 Page 3 of 6 Attachment A Q = M (h(g) - h(l)) to calculate the inventory requirement Where:

h(g) (Reference 1) = 1187 Btu/lbm (average between 1095 and 100 psia) [see note on page 22 of Reference 1]

h(l) = 118 Btuflbm (150 'F conservative temperature of CST) v(l) = 0.01634 ft3/bm @ 1500F All properties are from Reference 7.

6.11079 E8

0.01634

7.48 (1187 -118)

= 69867 gal This inventory matches very well the NUMARC formula and it will be used.

Therefore the inventory requirement for 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months of decay heat is 69867 gallons.

Condensate needed to remove the vessel stored energy to depressurize from 1095 psia to 100 psia.

Stored Energy in Fluid The fluid energy at full power (EPU conditions is) (Reference 4)

Fluid (EPU, t=0.0)

Mass Enthalpy Total Energy

_(bm)

(Btu/lbm)

(BTU)

Liquid 386,971 525.54 2.03369E8 Steam 13,186.12 1191.05 0.15705E8 Total 2.19074E8 The fluid energy at 100 psia is not changed from Reference 4. The level will be the same after depressurization for current licensed power (CLP) as for EPU. Hence the volumes of steam and liquid will be the same, as well as the enthalpy.

Fluid (depressurized at Mass Enthalpy Total Energy 100 psia)

(bm)

(Btu/lbm)

(BTU)

Liquid 510322.4 298.4 1.5228E8 Steam 703.13 1187.2 0.008E8 Total I_1.5311E8 Thus, the difference in fluid energy:

AE,,id = 2.19074e8-1.5311E8 = 0.65964E8 Btu

Calculation VYC-0886 Rev 2 CCN 04 Page 4 of 6 Attachment A Stored Enerev in Solid (From Reference 4)

Solid Total Solid Energy Heat Conductor Effective (EPU, time= 0.0)

(BTU)

Temperature (IF)

Liquid Exposed 0.9604399E8 601.24 Steam Exposed 0.25155507E8 609.18 Total 1.211995E8 602.83 Q = MCp AT = MCp (602.83 - 32) = MCp 570.83 MCp = 1.211995E8 /570.83 = 212321.53 Btu /0F Tsat @ P= 100 psia = 3280F (ASME Steam Tables-Reference 7)

At 100 psia:

Q= 212321.53 * (328-32) = 0.628472E8 Btu Total Energy removed from structures: AE sur,, 1.211995E8 - 0.628472E8 =

0.58352E8 Btu Total energy removed from the vessel during depressurization =

AEfluid + AE structures = 0.65964E8 + 0.58352E8 = 1.24316E8 Btu The inventory needed to remove this heat =

v = 1.24316E8 * (.01634) *7.48 =14,214gallons (1187-118)

Hence, the total inventory requirements = 69867 gallons +14,214 gallons = 84081 gallons

Calculation VYC-0886 Rev 2 CCN 04 Page 5 of 6 Attachment A For the CLP (Reference 1) the total CST inventory requirements for removing the decay heat and vessel stored energy = 75,837 gallons.

The TS (Reference 8) CST inventory of 75000 gallons is exceeded at both EPU and CLP for the 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months coping duration.

The HPCIIRCIC taking suction from CST has to make up for the vessel leakage (TS allowable and pump seal leakage of 61 gpm - Reference 6, page 17 of TER, also used in both Appendix R analysis (Reference 9, VYC-2270) and in Reference 1. The leakage amount does not change for EPU.

The needed CST inventory to account for leakage; V= 61 gpm

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months *60 min/hour = 29, 280 gallons.

This inventory, added to that already calculated for decay heat and depressurization would total:

V = 29280 + 84081 = 113361 gallons, which would normally be available from CST but, if not could easily be made available from the torus. Therefore, the conclusions of VYC-886 Rev2 that the Technical Specifications CST inventory requirement of 75000 gallons is not adequate for an 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months duration is valid at EPU. However, with Alternate AC (Vernon Tie) and low pressure systems available, sufficient inventory is available from the torus for the required 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

The power uprate results in a need for more inventory, 113361 gallons versus 105117 gallons at CLP.

Reactor Coolant Inventory The depletion of the available inventory in CST will not jeopardize reactor coolant inventory because makeup inventory can be provided from the torus. When the torus temperature exceeds 140 0F and RCIC and HPCI can not be used with suction from the torus, reactor inventory can be provided from the torus via low pressure pumps. Since VY is an Alternate AC plant, crediting use of the low pressure pumps is acceptable. This conclusion is unaffected by power uprate.

Loss of Ventilation The heat-up due to the loss of ventilation due to an SBO event for RCIC Room, HPCI Room, Main Steam Tunnel, Control Room, Switchgear Room, and Intake Structure is addressed in Reference 1.

RCIC Room The heat-up calculation is based on VYC-415 RevO (Reference 10 modified by CCN 1 (Reference 11)). The heatup is based on the piping temperature, RCIC turbine and Switch Heat Loss. The RCIC Room Temperature calculated in Reference 12 is unaffected by EPU.

Calculation VYC-0886 Rev 2 CCN 04 Page 6 of 6 Attachment A HPCI Room.'

The heat-up calculation is based on heat loads from VYC-0415 Rev 0 (Reference 10). The heat loads are from the piping and the BPCI turbine. The heat loads are unaffected by power uprate. Therefore the calculation for HPCI room heat-up is not affected by EPU.

Main Steam Tunnel The issue is isolation of HPCI and RCIC on high steam tunnel temperature.

Reference 13 calculated an increase of 0.6 'F in the normal temperature of the steam tunnel, at EPU.

The conclusion of VYC-886 Rev 2, that the main steam tunnel heat-up is slow on loss of ventilation and the reactor will already be in the process of cool-down, is valid at EPU.

Furthermore, Reference 14 (VYC-1347) concluded that the heat-up in the main steam tunnel is less than that required to isolate HPCI and RCIC. For the case when the feedwater and main steam isolates (SBO conditions), the peak room temperature from Reference 14 is 1740F (isolation temperature assuming loop accuracy) at approximately 18 hours2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months . Based on the results of Reference 13, the change in Main Steam Tunnel Heatup will be very small at EPU. Furthermore, procedure OT-3122 (Reference 15) limits HPCI & RCIC operation to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ; hence the reactor pressure after 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months should be low enough to permit operation of the Low Pressure Pumps (CS and RHR).

Therefore the impact of power uprate on heatup of the Main Steam Tunnel is negligible. It is recommended that calculation VYC-1347 be updated for EPU conditions.

Control Room Restoration of ventilation in the Control Room is governed by Procedure OT-3122 and is unaffected by Power Uprate. Control Room Heatup for loss of ventilation is unaffected by power uprate.

Switchzear Room The heat loads in the switchgear room are unaffected by the power uprate.

Intake Structure The heatup of the Intake structure on loss of ventilation with only 2 Service Water available is unaffected by the power uprate since the heat loads in the intake structure are unaffected by power uprate.

Torus Temperature The Torus Temperature calculation for SBO at power uprate was performed in Reference 16 (VYC-1628D CCN02). The peak suppression pool temperature is 187.9 'F.

BVY 05-072 Docket No. 50-271 Exhibit SPSB-C-52-2 Vermont Yankee Nuclear Power Station Proposed Technical Specification Change No. 263 - Supplement No. 30 Extended Power Uprate Response to Request for Additional Information Calculation VYC-1 347, Rev.O l Total number of pages in this Exhibit I (excludina this cover sheet) is 29.

l

7~_ x 4

t

/7 ORIGINAL:

Rev. 1:

Rev. 2:

Rev. 3:

PAGEI of 1 17 PAGES PAGE 1 of PAGES PAGE 1 of PAGES PAGE 1 of PAGES GA RECORD?

IMS NO.

M02.01,05 YES RECORD TYPE 09,C16.004 NO W.OJP.O. NO. _4055 YANKEE NUCLEAR SERVICES DIVISION CALCULATION/ANALYSIS FOR TITLE Main Flom Tunnel Heatup Calcution PLANT Vermont Yankee CYCLE N/A CALCULATION NUMBER VYC1347 F

g PREPARED BY

/DATE REVIEWED BY

_.DATE,9P APPROVED BY

/DATE SUPERSEDES CALCJREV. NO.

&_I 0 _

ORIGINAL

"~IA iaJ1:70 -t REVISION 1 REVISION 2 REVISION 3 7

KEYWORDS GOTHIC: Room: Heat-um: RRU Gig NUCLEAR SERVICES DIVISION G( -)

OF YANKEE ATOMIC ELECTRIC COMPANY 580 MAIN STREET.

BOLTON, MASSACHUSETTS 01 740 i

YANKEE NUCLEAR SERVICES DIVISION CALC. NO. VG1347 REV.

DATE 11-1-96 TITLE Main Steam Tunnel Heatup Calculation PREPARED BY Jim Pappas REVIEWED BY PAGE 2

OF TABLE OF CONTENTS Section Descriition Pare LIST OF TABLES..

3 LIST OF FIGURES.......................

4 1.0 PROBLEM DESCRIPTION 5

1.1 Objective.

5 1.2 Method of Solution.6 1.3 Design Inputs.

6 1.4 Assumptions.

9 2.0 PROBLEM ANALYSIS 10 2.1 GOTHIC Model Input......................

10 2.1.1 ControlVolumes......................

10 2.1.2 Thermal Conductors.11

2.1.3 Heaters

Main Steam Isolation Valves.11...................................

I l 2.2 GOTHIC Runs 20 2.2.1 Run MST.20 2.2.2 Run MST2.24

3.0 CONCLUSION

.29

4.0 REFERENCES

30 Appendices A

GOTHIC Run MST.35 B

GOTHIC Run MST2.81 C

Computer Code Evaluation....................

112 D

Reviewer's Comments....................

114

M-I YANKEE NUCLEAR SERVICES DIVISION CALC. NO. VYC-1347 REV.

DATE _11-1-96 TITLE Main Steam Tunnel Heatup Calculation PREPARED BY Jim Pappas REVIEWED BY PAGE 3

OF LIST OF TABLES Table No.

Description Pane 1.3-1 Thermo-Physical Properties.....................................................................

7 1.3-2 Outer Environment Temperatures.

2.1-la MST2 Dimensional Data..........................................................................

15 2.1-lb West Wall Dimensional Data.16 2.1-2a Piping Design Data.17 2.1-2b Piping Heat Transfer Surface Areas.18

YANKEE NUCLEAR SERVICES DMSION CALC. NO..VYC-1347 REV. -

DATE 11-1-96 TITLE Maln Steam Tunnel Heatup Calculation PP.RPARED BY Jim Pappas REVIEWED BY PAGE 4

OF LIST 0F FIGURES Figure No.

Description Page 2.1.3-1 MSIV Valve Outline Drawing.19 2.2-la MST1 Schematic.22 2.2-lb MST1 Temperature Profile.23 2.2-2a MST2 Schematic......................

26 2.2-2b MST2 Temperature Profile to Seven Days.27 2.2-2c MST2 Temperature Profile to Four Hours.28 A-1 MST1 Schematic.38 A-2 MST1 Input Tables 39 A-3

. MST1 Graphical Results....................

55 A-4 MST1 Output Verifying the MSIV Model.70 A-5 MST1 Output Showing Condensation Heat Transfer Fluctuations.73 A-1 MST2 Schematic.82 A-2 MST2 Input Tables..................

83 A-3 MST2 Graphical Results......................

98

I- __

-

I YANKEE NUCLEAR SERVICES DIVISION CALC. NO. VYC-1347 REV.

DATE 114t-9 TnTLE Main Steam Tunnel Heatup Calculation PREPARED BY Jim Pappas REVIEWED BY PAGE _5 OF 1.0 PROBLEM DESCRIPTION This calculation determines the temperature rise in the main steam tunnel with a loss of HVAC to document whether this rise will result in an automatic isolation of the HPCI and RCIC systems. The HPCI/RCIC excess air temperature switches, within the main steam tunnel, provide automatic isolation of the HPCI and RCIC lines if a temperature of 185'F +/- 5'F is sustained for longer than 30 minutes (References 23 and 24). The loop accuracy is 6-F (Reference 36). Therefore HPCI and RCIC isolation can occur at a steam tunnel temperature as low as 174'F. This high temperature isolation scheme is for line break protection and it is not intended for non-line break events, such as loss of main steam tunnel cooling under loss of normal power.

Normal ventilation in the main steam tunnel is supplied by the Reactor Building Ventilation System and by RRUs 17A and 17B, located in the tunnel. A Reactor Transfer Fan (RTF-IA/I B) exhausts air from the main steam tunnel at approximately 4200 cfm. Each fan has a total capacity of 14,400 cfm and takes inlet air from various locations in the Reactor Building. The RRUs circulate and cool air inside the main steam tunnel. The fan capacity of each RRU is 5000 cfm and service water, supplied to coils within the RRUs, provides the cooling.

RTF-1A and both RRUs are powered from 480v MCC 6A. This MCC is NNS and is supplied from 4160v Bus 1. RTF-lB is powered from 480v MCC 7A, which is also NNS, and is supplied from 4160v Bus 2.

Controls are located on the Turbine Building HVAC control panel, with auxiliary indications on the Control Room 9-25 panel. Typically, one fan and both RRUs are operating, with the second fan in stand-by. The operating fan and the RRUs maintain the main steam tunnel environment temperature at a yearly average of 125'F, as described in the Vermont Yankee Environmental Qualification Program (Reference 25). A review of temperature data for the main steam tunnel indicates that the air temperature can peak at about 150;F during the summer months (Reference 30).

1.1 Obiective The objective of this calculation is to determine the temperature rise of the air in the main steam tunnel, during a loss of normal power and under the following conditions:

Loss of HVAC in the main steam tunnel; Summer peak temperature for initial and boundary conditions.

Main steam and feedwater lines in the tunnel are:

Isolated (steam and water are not flowing, GOTHIC run MSTI).

Not isolated (steam and water are flowing, GOTHIC run MST2).

YANKEE NUCLEAR SERVICES DMSION CALC. NO. '

1 347 REV.

DATE 1-1-96 TITLE; Main Steam Tunnel Heatuo Calculation PREPARED BY Jim Pappas REVIEWED BY PAGE 6

OF 1.2 Method of Solution A lumped parameter GOTHIC model of the main steam tunnel is used to calculate the air temperature rise on loss of HVAC. GOTHICn(3341 is a general purpose thermal-hydraulic computer program for design, licensing, safety, and operating analysis of nuclear power plant coianainient and other confinement buildings. See Appendix C for verification of the GOTHIC version used.

The models consist of volumes, flow paths, & thernal conductors arranged and connected to represent the thermal-hydraulic response of the main steam tunnel. The thermal mass of each conductor is included in the GOTHIC computation.

1.3 Design Inputs 1.3.1 The thermo-physical properties for the materials used are shown in Table 1.3-1.

1.3.2 The boundary temperatures for spaces surrounding the main steam tunnel are shown in Table 1.3-2.

YANKEE NUCLEAR SERVICES DMVISION CALC. NO. WC-1347 REV._

DATE TITLE Main Steam Tunnel Heatup Calculation PREPARED BY Jim Pappas REVIEWED BY PAGE 7

OF TabL 1.3-1 Thermno-hysical Properties a) Superscript numbers refer to References in Section 4.0.

b) Assumed.

YANKEE NUCLEAR SERVICES DMSION CA.

NO.

I L347

. REV.

DATE '11-1-9 TITLE Main Steam Tunnel Heatup Calcultion PREPARED BY Jim PaDDas REVIEWED BY

-- PAGE 8

OF arbE e 1.3e2 Outer Environment Temperatures Nrma Normal 150*F 125°F 100*F 83*F('

Operation Peak Summer 160°F 130°F 120°F 90" ()

Notes a) Vermont Yankee FSAR (Reference 32), Table 2.3.2, Highest mean daily maxirrJm for summer months.

b) Vermont Yankee FSAR (Reference 32), Section 10.12, Summer design temperature.

YANKEE NUCLEAR SERVICES DIVSION CALC. NO. WY1347 REV.

DATE 1-96 TITLE Main Steam Tunnel Heatup Calculation-PREPARED BY Jim Pappas REVIEWED BY PAGE 9

OF 1.4 Assumptions The critical assumptions used in the GOTHIC models are as follows:

1.4.1 Initial main steam tunnel air temperature is 150F. This is bated on Reference 30 and is considered conservative. Reference 30, describes that this value is derived from a temperature clement that is close to hot process lines. Therefore, the corresponding ambient room temperature should be lower.

1.4.2 Initial main steam thermodynamic statepoint is saturated steam at 985 psia based on the heat balance shown on Figure 1.6-1 in the FSAR (Reference 32). Therefore, the temperature is 543'F.

1.4.3 Initial feedwater thermodynamic statepoint is saturated water at 373F based on the heat balance shown on Figure 1.6-1 in the PSAR (Reference 32). Therefore, the pressure is 179.8 psia.

1.4.4 HPCI and RCIC turbine steam supply temperatures are 5431F.

1.4.5 Both RRUs are inoperative for the analysis.

1.4.6 The air temperatures in the spaces surrounding the main steam tunnel are listed in Table 1.3-2 and are assumed to be constant throughout the transients.

1.4.7 In model MST1, where the main steam lines are isolated and the feedwater pumps are off, the four main steam lines (MS-IA through D) and the feedwater lines (FDW-14/15/16/17) dissipate the heat in the line volume, cooling down as they do so.

All other lines contain fluid at their respective constant temperatures, as listed in Table 2.1-2a.

1.4.8 In model MST2, where the main steam lines do not isolate, all lines contain fluid at their respective constant temperatures, as listed in Table 2.1-2a.

1.4.9 Miscellaneous piping, steel, and equipment are left out of the models.

1.4.10 The floor is left out of the models to add conservatism to the room heat-up.

1.4.11 The west wall contains a metal section through which the main steam lines pass and which two blowout panels are installed. This metal section is modeled in the GOTHIC runs. However, other non-concrete wall sections are not. They include:

a) ventilation duct with blowout damper in the north wall, b) a blowout panel and a blowout door in the south wall, and c) various duct work and pipe sleeves.

This is assumed to be crnservative since it inhibits natural circulation that would normally exist in the room.

.1 YANKEE NUCLEAR SERVICES DISION CALC. NO. WC;1 REV.

DATE 11-1-96 TITLE Main Steam Tunnel Ieatup Calculation PREPARED BY Jim Pappas REVIEWED BY PAGE 10 OF 2.0 PROBLEM ANALYSIS 2.1 GOTHIC Model Input The following sections describe the major input that was calculated for the GOTHIC models.

2.1.1 Control Volumes Main Steam Tunnel The main steam tunnel is Volume 1 in the models. The relevant dimensional data of the main steam tunnel for construction of the models are shown in Table 2.1-1. From these data, the wall surface areas and the room overall volume are obtained. The volume of the steam tunnel is:

VmsT

=(North Wall)x (East Wall)x(Height)

VMST

= 36.25'x 24'x 25.5 = 22,185 ft The hydraulic diameter is:

Dh _ 4A Pw where A is the cross sectional area of the volume (i.e.. the ceiling or floor area) and P. is the wetted perimeter. P. is defined by GOTHIC as S/h or the surface area of all structures divided by the height of the volume. S would, therefore, be the total surface area of all the walls and the ceiling. The floor is not modeled.

0 h A4Ah DI==S E

,h Anom+

Asoum + Ae*t + Ast-$ + Acip0 4(870X25.5) '

924.38 + 924.38 + 612 +612 + 870 Di = 225 It In the run where the main steam and feedwater lines are isolated, those lines are modeled as separate control volumes. The four main steam lines are lumped into one volume as are the two feedwater

YANKEE NUCLEAR SERVICES DIVISION CAMC. NO.

Mal 347

. REV.

DATE 11-1-96 TITLE Main Steam TUnnel HeatUp Calculaton PREPARED BY Jim Pasuas REVIEWED BY PAGE 11 OF lines. The volumes are obtained from the pipe data in Table 2.1-2b, and follow. The hydraulic diameters are simply the pipe diameters.

Main Steam Lines VSL = 4 X 7tC R.2 x L VMSL 4 X (8062 I 12) X 46.5 VMSL 263.75 f 3 Feedwater Lines VFW = X R) 2 14116 + L15 71)

VFDW it(6.781 / 12)2(45.7 + 479)

VFDW 93.90 fe 2.1,2 Thermal Conductors The input for the thermal conductors that represent the steam tunnel walls and ceiling is taken from Table 2.1-1. The floor is left out of the model to add conservatism. Typically there is little heat transfer through the floor of a heated room.

The thermally significant piping found in the main steam tunnel are described in Table 2.1-2. The GOTHIC input for these conductors is also shown in the table.

2.1.3 Heaters

Main Steam Isolation Valves The main steam isolation valves (MSIV) in the steam tunnel have a substantial amount of un-insulated structure that makes up the yoke and actuator. Figure 2.1.3-1 (Reference 39) shows the outline of the valve. Heat will conduct through and out of this structure into the main steam tunnel. There are four such valves in the tunnel.

The yoke of each MSIV consists of four 3' solid rods attached to the bonnet (Reference 40). The yoke acts as a support for the actuator and as a spring guide. Through the center of the yoke, the valve stem travels.

YANKEE NUCLEAR SERVICES DIVISION CALC. NO.

C137 REV.

DATE 11-1-.6 TITLE Main Steam Tunnel Heatup Calculation PREPARED BY Jim Papoas REVIEWED BY ____

PAGE 12 OF The method of modeling the heat transferred to the main steam tunnel by this assembly will be to treat each 3" yoke rod and the stem as a fin. The stem will be modeled as though it were a fifth yoke rod.

Therefore, each MSIV will be modeled as having five 3' solid rod fins heated at one end. The heated end is that attached to the body of the valve. It is assumed that the actuator is far enough away from the valve body that any heat conducted to it is negligible.

GOTHIC cannot model this situation because it involves two-dimensional conductive heat transfer.

GOTHIC can only model one-dimensional conduction. Therefore, a formulation of the heat rate provided by the yokes will be derived here and input into GOTHIC as a theater".

The general equation for such a fin is (Reference 29):

q = hk

- T,.)tanh(mL) where:

q = heat rate (Btulhr) h = convective heat transfer coefficient (Btulhrft eF)

P = perimeter of the fin ( sd ) (ft) d = diameter of the rod (ft) k = thermal conductivity of the rod material (BtulhrftoF)

A cross sectional area of the fin (if2)

T= temperature of the heated end ('IF)

T co =ambient room temperature (F) m =

(I')

L = length of the fin (if)

The values in the following table will be used. The value for h is taken from Reference 38 and is considered to be conservative. In a transient calculation, it would be expected to vary around a value of 0.5 Btu/hr-ft2.F to 1.0 Btu/hr'ft2-. F. The length, L, is taken as the 'AC' dimension from Figure 2.1.3-1. This is clearly much longer than the actual length of the yoke. However, the yoke dimension is not given. So, the more conservative, longer length is arbitrarily used. This presents hardly any penalty in heat rate to the room because the value is used in the tanhO function which is barely sensitive to the length. For example, using the 9 ft value tanh(91 - 0.9999 and using half that value tanh(4.5) = 0.9998.

YANKEE NUCLEAR SERVICES DIVISION TITLE Main Steam Tunrnel Heatup Calculation PREPARED BY Jim Pappas

REV, CALC. NO. VC1347 REV.

DATE -*11-1-96 IEWEDBY PAGE 13 OF __

M-vr' h

1.65 Btulhrft2 *F RFperence 38

=3in d

Refereince 40 0.25 ft P

= (0.25)

= 0.785 ft k

25 BtulhrftF Table 1.3-1 itd2

=

44 A2

. 0.049 fe m

m

_ I165 x 0.785

25 x 0.049

= 1.028 t

= 108 in Figure 2.1.3-1 L9 ft (See discussion above)

The temperatures will be taken from the GOTHIC run using control variables. This will allow the temperature difference to vary with time to more accurately represent the changing heat transfer rate.

The source temperature, T., will be taken as the temperature inside the main steam line. This is highly conservative since the more appropriate value would be that rf the bonnet. Calculation VYC-660 (Reference 40) is a state-point calculation of the heat conduction through the same MSIV structure. For the state-point modeled in VYC-660, the steam inside the pipe is modeled at 545F and the bonnet temperature is calculated to be about 375F. So, as expected, the bonnet is cooler than the steam inside the pipe. However, the assumptions in VYC-660 are not all consistent with those of the present calculation and a definitive correlation between these two temperatures is not readily derivable. Therefore, using the steam temperature is certainly conservative since.it is clearly bounding

- the bonnet can never be hotter than the steam.

1,

YANKEE NUCLEAR SERVICES DMSION CAMC. NO. VC 1347 REV.

DATE 11-1-96 TITLE M-1n Steam Tunnel Heatup Calculation PREPARED BY Jim Pappas REVIEWED BY PAGE 14 OF The ambient temperature, T.,, is the bulk room temperature calculated by GOTHIC.

So, the heat rate generated by a single yoke rod is:

q = ( 65 x 0.785 x 25 x 0.049)T, - T.)tanh(1O28 x 9) q = t26(U5 - T,,,) Btulhr Each of the four MSIVs is to be modeled as having five such rods, and GOTHIC requires input in units of Btu/sec. So, the final input to GOTH(C is:

q =4 MS`Vs x 5 Rods x 360 hr x 126(T

-T.)

q 0.007er - T.) Btuls In GOTHIC this will be represented as a heater with a heat rate of 0.007 Btu/s multiplied by a forcing function. The forcing function is in turn equated to a control variable. And, the control variable represents the temperature difference between the main steam line and the room average of the tunnel.

YANKEE NUCLEAR SERVICES DMSION CAMC. NO. VYC-1347 REV.

DATE 11-1-96 TITLE Main Steam Tunnel Heatun Calculation PREPARED BY Jim Pappas REVIEWED BY PAGE 15 OF Main Steam Tunnel Dim ensInaLData i I I

36.25(1 36.25("11 24(10) 36.25(11 Height I Wdth 25.5(2) 25.5(12) 25.512) 2400)

Area87.

(Ae) 924.38 924.38 612.0 870.0 Thickness 4.01 4.0(10) 4

3) 4.0(11)

(if)

Notes Superscript numbers refer to References In Section 4.0.

YANKEE NUCLEAR SERVICES DIMSION TITLE Mai-Steam Tunnel Heatup Calculation PREPARED BY Jim Pa2Ras REVI CALC. NO. VYC-1347 REV. _

DATE 11-1-96 EWED BY PAGE 16 OF Table.2Z.Llb West Wall Dimensional Dat Superscript numbers refer to References in Section 4.0.

YANKEE NUCLEAR SERVICES DMSION CAC. NO. -1 L347 REV. _

DATE 11-1-96 TITLE Main Steam Tunnel Heatup Calculation PREPARED BY Jim Papeas REVIEWED BY PAGE 17 OF lable 2. - 2a MS1A 18 arm 80 3.5M' 543" MS-B IBM soX)8 3.5a")

543P MS41C 1 8R6o8 3 5m 543M MS413 DB S

a6D 3.>n543 MS-4A° '

10(19 80 3.5(19) 543 MS.4B'b 1auC u

2.0n"s 5 43M FDW-14116 16(18) 120 2.0(16)(8) 3730 FDW-15117 16(8al 120 2.0(40'(2) 373)

MS.5A("

3M) 160 20(22) 543w RCIC-1) 4(21) 120 None 12')

140>"

RCIC-2tn 421) 120 None(2" 140")

RCIC-8B° 4(21) 120 2.0 1) 140°'

RCIC-80 4(214.

120

2.05'1 140(}

HPCI-1 5811) 14M 120 2.5(27) 140"')

HPC 1-15A")r 410%

120 2.5(27) 140(')

I Notes a) Reference 27 says 2.5" b) HPCI Steam Supply c) RCIC Steam Supply d) FSAR (ReferencX 32). Figure 6.4-1 (Highest temperature at Location 2) e) Superscript numbers refer to References in Section 4.0.

f) RCIC Discharge g) HPCI Discharge h) FSAR (Reference 32), Figure 4.7-3 (Highest temperature at Location 3) i) Assumption 1.4.2 j) Assumption 1.4.3

YANKEE NUCLEAR SERVICES DMSVION CAiC, NO. WC-t347 REV.

DATE 11-1-96 TITLE Main Steam Tunnel Heatup Calculation PREPARED EBY Jim Pappas REVIEWED BY PAGE -A18 OF lable 2 2' Pioing Heat Transfer Surface Areas MS-1A 8.062 9.000 46.5"6, 304.3 MS-1B 8.062 9.000 46.5(67 304.3 MS-IC 8.062 9.000 46.56.-7) 304.3 M4S.ID 8.062 9.000 46.5*5(

304.3 MS4A0' 4.781 5.375 17.6("')

81.8 MS-4Btb 4.781 5.375 35.2t19) 135.9 FDW-14116 6.781 8.000 45.7'8) 239.3 FDW--i5117 6.781 8.000 47.9p5) 250.8 MS5A°)

1.312 1.750 46.7(22) 91.7 RCIC-1°'

1.612 2.250.28.7t2) 33.8 RCIC-2tQ 1.812 2.250 29.7(2')

35.0 RCIC4BM 1.812 2.250 6.5(1) 14.5 RCIC-8AM 1.812 2.250.

11.4(21) 25.4 HPCI-IS5B()

5.906 7.000 40.6(M 202.0 HPCI-15A';

j 5.906 7.000 9.2c 45.8 I

i Notes a) Area = 2n(Outer Radius + Insulation) x (1 ftl12 In) x Length b) HPCI Steam Supply c) RCIC Steam Supply..

e) Superscript numbhrs refer to References In Section 4.0.

) RCIC Discharge

9) HPCI Discharge

I I

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~ ~

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CRNU*N 1AG

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YANKEE NUCLEAR SERVICES DMSION CALC. NO. WC-1347 REV.

DATE -96 TITLE Main Steam Tunnel Heatun Caiculathn PREPARED BY Jim Pappas REVIEWED BY PAGE 20 OF 2.2 GOTHIC Runs 2.2.1' Run MST1 This run of the main steam tunnel heat-up represents a typical loss-of-normal power event. On a loss-of-power, the HVAC system trips and the TASIVs and feedwater pumps isolate. The room then heats up because of the heat gain from the pipes within it. However, the major loads are from the main steam and feedwater lines and the fluids in those lines are not flowing. Therefore, their heat gain to the room diminishes as the transient progresses and the room eventually peaks out and then begins to drop in temperature.

This run represents a typical heat-up of the tunnel following lkss of ventilation, however many conservatisms are included so that the results are assured to bound a true event. These conservatisms include:

The initial main steam tunnel temperature of 150'F is based on the Reference 30 data and represents a peak room temperature as opposed to an average room temperature. A more representative average (initial) room temperature would be something lower.

Miscellaneous structures and equipment in the room are not modeled. They would act as heat sinks resulting in a temperature rise that is slower than that predicted by GOTHIC.

Miscellaneous 'cold' piping, such as service water piping, is not modeled as heat sinks.

Wall openings such as ventilation ducts/dampers or pipe sleeves are not modeled inhibiting cooling by natural circulation.

Natural circulation through the RRUs is not modeled. The RRUs trip on loss of power however they continue to receive cool service water and would contribute a small amount of cooling.

On a loss of power, HPCI and RCIC would automatically start resulting in flushing some of the 373F water from the feedwater lines and replacing it with 140F water. This is not accounted for.

The MSIV heat gain is conservative as described in Section 2.1.3. Most notably, the source temperature of the yoke, modeled as a series of fins, is the steam temperature itself as opposed to the bonnet temperature of the valve.

The floor as a heat sink is not modeled.

The non-conservatisms in the model are:

Main steam line drains are not modeled. They would add heat to the room but only a small amount because the lines are about 2W' NPS. This is believed to be counteracted by the lack of 'cold' piping being modeled as well.

There is no account for MSIV leakage that would continuously add a slight heat load to the main steam lines. (Run MST2 in Section 2.2.2 accounts for this).

- _M ___ --

I YANKEE NUCLEAR SERVICES DMSION CAMC. NO. _VYQ-1 i47 REV.

DATE 11-1-96 TITLE Main Steam Tunnel Heatup Calculation PREPARED BY Jim Pappas REVIEWED BY PAGE 21 OF _

There Is no spatial definition in the model, therefore an axial temperature gradient is not calculated; Because the HPCI/RCIC temperature switches are in the upper, ceiling, area they may experience a higher temperature than that of the bulk room. This is believed to be counteracted by the initial room temperature of 150'F which represents a temperature from a hot area of the steam tunnel. (See Assumption 1.4.1).

It is believed that the conservatisms listed above far outweigh the non-conservatisms. Therefore, it can be'assured that the true heat-up profile of the main steam tunnel will be a curve that is below -

and therefore bounded by - the GOTHIC result.

The GOTHIC model MSTI is shown schematically in Figure 2.2-la. It consists of the following:

a Volume 1 representing the main steam tunnel.

Volume 2 representing the main steam lines isolated at t - 0 seconds.

Volume 3 representing the feedwater lines with pumps off and no flow at t 0 seconds.

Flow path 1 connecting Volume 1 with a pressure boundary condition 1P. This flow path and boundary condition are used to maintain the pressure within the main steam tunnel at 14.7 psia as the air heats up.

Thermal Conductors 1-6, 8, 9, 11-16 connecting the heat sources and sinks to Volume 1.

I Thermal Conductor 7 connecting Volume 2 to Volume 1.

Thermal Conductor 10 connects Volume 3 to Volume 1.

Heater 1 representing the MSIVs.

Appendix A contains the detailed listing of the GOTHIC input for this run. Included are graphical results and calculations validating the run. The model is run for 7 days to determine the temperature rise profile of the air in the main steam tunnel. The heat-up of the main steam tunnel is shown in Figure 2.2-lb for the full 7 days.

The graph shows that the steam tunnel reaches a peak average temperature of 174'F after approximately 3/4/4 of a day. It then drops during the remainder of the transient. The peak is considered to bound the actual peak that would result during a true loss-of-ventilation scenario because of the conservatisms discussed above.

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CALCULATION NO VYC-134 7 ATTACHMENT-PAGEOF___

10 -3 I- ?r P65 Z

YANKEE NUCLEAR SERVICES DMSION CALC.NO. VYC1347 REV.

DATE-11-96 TITLE Main Steam Tunnel Heatup C2'culation PREPARED BY Jim Pansas REVIEWED BY _

PAGE 24 OF 2.2.2 Run MST2 This run of the main steam tunnel heat-up represents an extreme loss-of-normal power event. As stated in Section 2.2.1, on a loss-of-power, the MSIVs and feedwater pumps normally isolate.

However, the possibility exists that one or more isolation function fails - suci. as a MSIV not closing.

Furthermnore, as stated in the non-conservatisms of run MSTI, it is more than likely that some leakage would exist past the MSIVs.

Justifiably quantifying such conditions is not straight forward. However, the situation can be bounded. The most bounding scenario is that none of the main steam any fecdwater lines isolate and the steam/water continues to flow. The initial temperature of the fluids within these lines is, therefore, constant throughout the transient resulting in a much higher heat gain to the room. This modeling technique also clearly bounds any postulated leakage past isolated MSIVs.

The model, itself, is identical to MST1 except:

the volumes representing the main steam and feedwater lines are removed.

the conductors (7 and 10) that connected those volumes are moved into the main steam tunnel volume as internal conductors.

the boundary heat transfer coefficients on conductors 7 and 10 are fixed temperatures representing the steam and feedwater temperatures.

All other conservatisms and non-conservatisms listed for run MSTI remain in this run.

The GOTHIC model MST2 is shown schematically in Figure 2.2-2a. It consists of the following:

Volume I representing the main steam tunnel:

Flow Path I connecting Volume 1 with a pressure boundary condition I P. This flow path and boundary condition are used to maintain the pressure within the main steam tunnel at 14.7 psia as the air heats up.

Thermal Conductors 1 - 16 connecting the heat sources and sinks to Volume 1.

Heater 1 representing the MSIVs.

Appendix B contains the detailed listing of the GOTHIC input for this run and graphical results. The model is run for 7 days to determine the temperature rise profile of the air in the main steam tunnel.

The heat-up of the main steam tunnel is shown in Figures 2.2-2b for the full 7 days and 2.2-2c for the first four hours. The first four hours is of particular interest for Appendix R scenarios.

YANKEE NUCLEAR SERVICES DIVSION CAC. NO. YWCaJ347 REV.

DATE 11-1-96 TITLE Main Steam Tunnel Heatup Calculation PREPARED BY Jim Panoas REVIEWED BY PAGE 25 OF The graphs show that the steam tunnel reaches an average temperature of 1722F after four hours. It continues to rise until it is about 207F at 7 days and still rising.

As with MST1, these results are considered to bound the actual temperature rise that would result during such a scenario. Furthermore, because the scenario itself is extreme by nature, the results greatly bound any possible steam tunnel heat rise that may be postulated.

M I

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ANKEE ATOMIC ELECTRIC COMPANy CALCUtAT(fIO ND V

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Steam Tunnel Bulk Room Temperature to 4 Hours

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2 25 3

3.5 4(

Time (hours)

GOTHIC 41. 1 IQA1-c 10/99 16:07:43 AW-I YKEE ATOMIC ELECTRIC COMPAy CALCULATiON No n

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ATTACHMENT A

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YANKEE NUCLEAR SERVICES DIVISION CAM. NO.M 47 REV.

DATE-11-1-96 TITLE -Main Steam Tunnel Heatup Calculation PREPARED BY Jim Pappas REVIEWED BY PAGE 29 OF

3.0 CONCLUSION

The results of the two GOTHIC runs show the air temperature in the steam tunnel to approach about 172F in the first four hours of each transient. Both transients show almost the same profile for that time frame because the cooldown of the main steam and feedwater lines is not large enough in the first four hours to have a significant effect on the room temperature rise.

In the case where the main steam lines and feedwater lines isolate, the peak room temperature is about 174'F at approximately 18 hours2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months . In the case where these lines do not isolate, the room temperature rises to 174F at about 61h hours. It continues to rise and is about 207'F at the end of the seven day -ransient and still rising.

As discussed in Section 2.2, the many conservatism included in the model offer a high degree of confidence that the GOTHIC results envelop any true heat-up profile of the steam tunnel. Therefore, the actual room heat-up is expected to be something less and it is concluded that HIPCI and RCIC would not isolate under the conditions modeled.

The results of this calculation do not affect the PSAR. Technical Specifications, Technical Programs, or controlled drawings.

ML052220446

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2.1.3 Heaters

3.0 CONCLUSION

4.0 REFERENCES

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3.0 CONCLUSION

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ML052220446

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Subject:

Subject:

Subject:

Title:

2.1.3 Heaters

3.0 CONCLUSION

4.0 REFERENCES

2.1.3 Heaters

3.0 CONCLUSION

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