Text

Forwards Response to NRC GL 95-07, Pressure Locking & Thermal Binding of Safety-Related Power-Operated Gate Valves
	ML20113B086
Person / Time
Site:	Brunswick
Issue date:	06/20/1996
From:	Campbell W; CAROLINA POWER & LIGHT CO.
To:	; NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
	BSEP-96-0225, BSEP-96-225, GL-95-07, GL-95-7, NUDOCS 9606260168
	Download: ML20113B086 (39)
	v • d • e

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CP&L Carolina Poveer & Light Company William R. Campbell PO Box 10429 Vice President Southport NC 28461 0429 Brunswick Nuclear Plant SERIAL: BSEP 96-0225 JUN 201996 United States Nuclear Regulatory Commission ATTENTION: Document Control Desk l

Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS 1 AND 2 DOCKET NOS 50-325 AND 50-324/ LICENSE NOS. DPR-71 AND DPR-62 RESPONSE TO NRC GENERIC LETTER 95-07, " PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES" Gentlemen:

On August 17,1995, the NRC issued Generic Letter (GL) 95-07, " Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves." CP&L provided the i

requested information in our February 13,1996 letter (Serial: BSEP 96-0051) and a follow-up response on April 26,1996 (Serial: BSEP 96-0157). CP&L received the NRC's May 16, 1996 request for additional information on May 21,1996, and is providing the requested l

information in the following enclosures.

Please refer any questions regarding this letter to Mr. Mark Turkal at (910) 457-3066.

Sincerely, aceclis OAg William R. Campbell GMT/gmt i

Enclosures:

1. Response

2. ESR 9600148

3. Prior Valve Modifications List

4. List of Regulatory Commitments 9606260168 960620 PDR ADGCK 05000324 P

PDR i

Tel 910 457-2496 Fox 910 457 2803

Document Control Dssk BSEP 96-0225 / Page 2 William R. Campbell, having been first duly sworn, did depose and say that the information contained herein is true and correct to the best of his information, knowledge and belief; and the sources of his information are officers, employees, and agents of Carolina Power &

Light Company.

d( n L O - Q. Y k 0 h My commission expires: b i ? g ((f(,

cc:

Mr. S. D. Ebneter, NRC Regional Administrator, Region 11 Mr. C. A. Patterson, NRC Senior Resident inspector - Brunswick Plant Mr. D. C. Trimble, Jr., NRR Project Manager - Brunswick Plant The Honorable H. Wells, Chairman - North Carolina Utilities Commission l

ENCLOSURE 1 BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 NRC DOCKET NOS. 50-325 AND 50-324 OPERATING LICENSE NOS. DPR-71 AND DPR-62 RESPONSE TO NRC GENERIC LETTER 95-07, " PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES "

On August 17,1995, the NRC issued Generic Letter (GL) 95-07, " Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves." CP&L provided the requested information in our February 13,1996 letter (Serial: BSEP 96-0051) and a follow-up responso on April 26,1996 (Serial: BSEP 96-0157). CP&L received the NRC's May 16, 1996 request for additional information on May 21,1996, and the following additional information is provided:

NRC Reauest 1:

In your submittal of April 26,1996, you stated that an analysis of the thermal environment for valves 1/2-E41-F042, HPCI Suppression Pool Suction, has been completed that determined that they are not subject to thermally-induced pressure locking. Please provide this analysis for our review.

CP&L Resoonse:

The analysis of the thermal environment at the ll2-E41-F042 valves is included as.

NRC Reauest 2:

BSEP has included the reactor core isolation cooling (RCIC) system in the GL 95-07 program due to its safety significance. In your submittal of February 13, 1996, you state that RCIC suppression pool suction valves 1/2-E51-F031 are not susceptible to thermally-induced drag forces. State whether conductive and convective heat transfer from the suppression pool during a design basis event was considered in this evaluation.

CP&L Resoonse Conductive and convective heat transfer from the suppression pool during a design basis event were considered in the review for susceptibility to thermally-induced pressure locking.

These effects were ruled out based on the thickness of the containment wall and the fact that the inboard suction line is a horizontal pipe approximately 9 feet,10 inches long.

Figure 5.4.6-4 of the Brunswick UFSAR indicates that the maximum expected suction temperature from the suppression pool is 140 F. As pointed out in NUREG-1275, volume 9, page 6, "The lowest temperature at which this type of f ailure was reported in these events was slightly below 200 F." Therefore, thermally-induced pressure locking is not expected.

E1-1

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' The initial review for program scopa identified the f act that tha maximum suppression pool l

temperature after a design basis LOCA may be as great as 203 F. Thus, the valves were included in the scope of the program to ensure that they received a more detailed review.

l l

NRC Reauest 3:

Through review of operational experience feedback, the NRC staffis aware ofinstances in which licensees have completed design or procedural modifications to preclude pressure locking or thermal binding that may have had an adverse impact on plant safety due to incomplete orincorrect evaluation of the potential effects of these modifications. Please describe evaluations and training for plant personnel that have been conducted for each design or procedural modification completed to address potentialpressure locking or thermal binding concerns.

CP&L resoonse 1

The scope of the review CP&L conducted for Generic Letter 95 07 included and re-evaluated the valves identified as having been previously modified due to pressure locking and thermal binding concerns.

Valves identified as having been previously modified are listed in Enclosure 3. The following summarizes the limited modification types CP&L used at BSEP to address pressure locking I

and thermal binding concerns:

I All valves listed either had a hole drilled in the valve disc or a bonnet pressure equalizing valve installed to address pressure locking.

To address the thermal binding issue some flex-wedge valves had been replaced with double disc valves. Also, the High Pressure Coolant Injection (HPCI) system Turbine Steam Admission valves (F001) and the HPCI Injection valves (F006) actuators were replaced with Ball-Screw Actuators which provided additional thrust margin.

Operation of valves is controlled by the sites " Plant Equipment Control" procedure (OAP-013). This procedure covers the training content for individuals who manipulate valves and the concepts of thermal binding and pressure locking are listed. Specific training to support these previous modifications was not identified.

l No new modifications were required as a result of the Generic Letter 95-07 review.

E1-2

ENCLOSURE 2 BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 NRC DOCKET NOS,50-325 AND 50-324 OPERATING LICENSE NOS DPR 71 AND DPR-62 RESPONSE TO NRC GENERIC LETTER 95-07, " PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES "

ENIGINEERING SERVICE REQUEST 9600148 ANALYZE THERMAL ENVIRONMENT AT 1/2-E41-F042 i

l

_, _,__,__,__ -,, ~ - - - - - - - - - - _ _ _ - _ - _ _ _ _ _ _ _ -

4 Pagi 1 of }J.

Form 1 ENGINEERING SERVICE REQUEST ESR #

Hov a WR/JO #

Reference:

NAS Before Closeout

Reference:

PNSC Before Approval / implementation NRC Before implementation

Reference:

Problem Resolution:

This evaluation (attached) determined that the HPCI Suction Valves (1/2-E41-F042) are not susceptible to thermally-induced pressure locking.

List Of Effective Pagest 1 -31 Revision 0 0 Continu.d APPROVAL l

ls this a modification which constitutes a reduction in design margen?

Interim Approval Required?

O Yes (PGM approvalis required)

O yes O No

@ N/A

@ No (Engirdenng Mgr signs for PGM)

{

A n

(

g/j 7 /9 g Responsible Engineer JIM PEARSON Responsible Manager (Print Name, Sign, Date)'

g ll

)

jpgjf(

N Plant General Manager IPrint Name, Sign, Date/

gj)

Procedure: OPLP-30 Revision 4 DCM02 10/18/95

Carolins Powtr & Light Company, BNP EsR 9600148

. Temperature Effects of HPCI Gland seal Exhauster Failure Revision 0. Page 3 of 31 EXECUTIVE

SUMMARY

ESR 9600114 determined that there is a potential for thermally-induced pressure locking of 1/2-E41-F042 if the Gland Seal Exhauster (GSE) fails during HPCI operation. The following sequence of events was postulated:

GSE failure during HPCI operation 345 lbm/hr (maximum) steam leak into the HPCI toom HPCI room temperature increases l

l l

l The bonnet temperature of 1/2-E41-F042 increases. The valves are j

assumed to be full of water, so pressure also increases Automatic HPCI suction transfer is initiated 1/2-E41-F042 fail to open due to pressure locking l

Since it was determined that there is a potential for thermally-induced pressure locking, it was concluded that a more detailed analysis is required.

This ESR performed the required analysis.

Based on this analysis, it has been determined that the postulated steam leak will not increase the temperature of the HPCI room enough to pose a threat of thermally-induced pressure locking of 1/2-E41-F042. Therefore, further corrective actions are not required.

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Carolina Power & Light Company, BNP ESR 9600148 Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Page 4 of 31

1.0 BACKGROUND

AND PURPOSE

1.1 BACKGROUND

ESR 9600114 concluded that there is a potential for thermally-induced pressure locking of 1/2-E41-F042. This may occur if the HPCI Gland Seal Exhauster (GSE) fails and allows leakage through the turbine and control valve steam seals at a rate of up to 345 lbm/ hour. The expected temperature increase in the HPCI room was not quantified in ESR 9600114. However, it was qualitatively determined that there is a potential for

~

thermally-induced pressure locking of 1/2-E41-F042. It was concluded that a more detailed thermal analysis of the temperature response of the HPCI room is required in order to estimate the actual maximum temperature after a GSE failure.

1.2 PURPOSE The purpose of this analysis is to review the heating effects in the HPCI room after a failure of the Gland Seal Exhauster. It will estimate a bounding value for the maximum HPCI room temperature and evaluate the potential for thermally-induced pressure locking at that temperature.

l

Carolina Power & Light Company, BNP ESR 9600148

. Temperature EfTects of HPCI Gland Seal Exhauster Failure Revision 0. Page 5 of 31 2.0 ASSUMPTIONS It is assumed that the following conditions are in effect when the Gland Seal Exhauster (GSE) fails and begins to add heat to the HPCI room.

2.1 HPCI is operating in a normal flowpath at 4,250 gpm (FSAR Table 6.3.1-1) with CST suction. No other component failures or steam leaks are present.

2.2 The maximum steam flow from the seals is 345 lbm/ hour, as described in Reference 11.

2.3 At least one RHR Room Cooler is available and running, with a heat removal capacity of 210,000 BTU / hour (References 4 & 10).

2.4 The maximum temperature of the CST water being pumped by HPCI is 90*F.

2.5 Since this analysis determines an equilibrium temperature in the HPCI room, the heat capacities of the structures and components will not be considered.

2.6 The temperature of the RHR rooms and the area above the HPCI room is assumed to be 104 F.

2.7 The temperature of the earth outside the east wall of the HPCI room is assumed to be 70*F.

2.8 It is assumed that no heat transfer occurs from the HPCI room through the West wall into the Suppression Pool.

w Carolins Power & Light Company, BNP ESR 9600148

. Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Page 6 of 31 3.0 ANALYTICAL MODEL OF THE HPCI ROOM 3.1 PHYSICAL ARRANGEMENT Relative to most of the shapes and components normally evaluated in heat transfer analyses, the geometry of the HPCI toom and its components is complex. A general arrangement of the important components is shown in Figure 1.

FIGURE 1: HPCI ROOM ARRANGEMENT (RHR ROOM COOLERS) t t

_]

8-ourtsr SWALLS 9 NORMAL b PIPING S

WPPW

. VSucuoN

\\

QLEAK O

r"%

TURBINE wn--mmmmmmme PUMPS Heat is normally added to the HPCI room by heat loss through the insulated steam supply and exhaust lines, by heat loss from the turbine, and by lighting. This is modeled in the above sketch as qNontat. In the case ofinterest, it is assumed that a Gland Seal Exhauster failure causes leakage of sealing steam into the HPCI room. This additional heat load is modeled as qLEAK. If the HPCI room is modeled as a control volume, then heat transfer occurs by convection / conduction through the walls (qWALLs) and the piping (qP! PING). Additional heat is removed by a constant flow of cooled air into the HPCI room, which is exhausted via two outlets.

According to Reference 5, the heat added to the HPCI room by the turbine and steam lines is 36,400 watts, or 124,197 BTU /Hr. Reference 6 determined that the heat added by normal room lighting is approximately 6,433 BTU /Hr. Thus, the total normal heat load in the room is 130,630 BTU /Hr.

The heat load imposed by the postulated leak is evaluated in section 4.3 as 387,849 BTU /Hr. Therefore, the maximum heat input to the HPCI room is 518.479 BTU /Hr.

Carolina Power & Light Company, BNP ESR 9600148 Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Page 7 of 31 3.2 CONTROL VOLUME MODELS 3.2.1 SIMPLE CONTROL VOLUME One method of evaluating the temperature in the HPCI room is to treat it as a simple control volume, as shown in Figure 2. This model assumes that the heat input to the HPCI room is homogeneously distributed throughout the HPCI room.

FIGURE 2: HPCI ROOM CONTROL VOLUME MODEL System Heat Losses HPCI ROOM Room Coolers Conduction Steam Leaks In Room Through N

Walls and Ceiling Heat Removed By Water Flowing Through g

l Un-insulated Segments of Piping in HPCI Room This model will be evaluated in section 4.0 as " Case 1". For additional conservatism, the HPCI room will be treated as if no heat is removed by the room coolers.

Each heat removal mechanism, except for the RHR room coolers, will be evaluated in terms of the temperature in the HPCI room. Since the maximum heat input is known, an equation for thermal equilibrium (heat in = heat out) can be written. The resultant equation can be solved numerically to determine the HPCI room temperature when heat flow is at equilibrium

Carolins Power & Light Company, BNP ESR 9600148 Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Page 8 of 31 l

l l

3.2.2 MODIFIFD CONTROL VOLUME There are several concerns associated with the model assumed in figure 2. First, the l

major component of heat addition into the HPCI room is not evenly distributed, but l

instead is released at two discrete points (the turbine steam seals). Second, the leaking swam is not applied evenly to all parts of the control volume. It is more likely to impinge more readily on the (un-insulated) pumps and piping nearest the leaks. Thus, the pumps and piping close to the leaks are most likely to experience significant condensation.

Third, since much of the heat is added by leaking steam, a phase change (condensation) within the control volume will complicate the model. The presence of condensation in the HPCI room can cause the convective heat transfer coefficient (h) to vary by a factor of more than 1,000. Finally, since the room is supplied with cool air and is vented, there is a potential that some of the leaked steam will be transported to an area outside the HPCI room before it can give up its heat by condensation.

Because of the concerns discussed above, a modified model, as shown in figure 3, will be adopted.

l FIGURE 3: MODIFIED HPCI ROOM CONTROL VOLUME MODEL i

Cool AirIn

. Heated Air Out System Losses Heat Released By Cooling Liquid Water Flowing Through

(-

Un insulated Piping in N-HPCI Room Steam Leaks In Room

/

(Impinging & Condensing on Un insulated Piping)

The physical interpretation of this model is that leaking steani condenses on un-insulated piping. It then drips to the floor, which is assumed to be an insulator. Liquid is assumed to reach the floor at 212'F. As it cools, it gives up heat to the air in the HPCI room.

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1 Carolina Power & Light Company, BNP ESR 9600148 Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Page 9 of 3 t 3.2.2 MODIFIFD CONTROL VOLUME (continued)

The model shown in figure 3 will be evaluated in section 5.0. In order to used this model, l

several simplifying assumptions will be made.

1.

The leaking steam is assumed to condense from reactor steam to room-

{

temperature water and to release all ofits energy into the HPCI room. No steam is assumed to be carried out of the HPCI room for condensation elsewhere.

4 2.

It will also be assumed that the enthalpy change from reactor steam to saturated liquid at 212 F will take place on cool piping surfaces. However, the remaining i

heat released as the liquid cools from 212'F to room temperature will be assumed

)

l to be transferred entirely to the air in the HPCI room. No liquid at elevated l

temperatures will be assumed to reach the sump in the HPCI room 3.

For simplicity, it will be assumed that condensation occurs only on the HPCI discharge line. the pumps, and on that portion of the suction line which has flow through it. Additional heat removal by condensation on walls and passive lines will not be credited.

j 4.

No credit will be taken for heat transfer by conduction through the walls or ceiling, or through the CRD lines which also traverse the HPCI room.

5.

It will be assumed that the heat released by condensation will be removed by the HPCI piping. The remaining heat will be removed by the influx of cool air from the room coolers.

6.

The suction valves are located about halfway between the floor and ceiling of the i

HPCI rooms. However, no credit will be taken for thermal stratification.

l Using the modified model of the HPCI room shown in figure 3, and the assumptions l

discussed above, a bounding steady-state room temperature will be estimated. This temperature will be evaluated to determine the probability of thermally-induced pressure locking within the suction valves.

l

u Carolina Power & Light Company, BNP ESR 9600148 Temperature Effects of HPCI Gland Seal Exhauster Failure Revision O. Page 10 of 31 3.4 ANALYTICAL MODEL OF HPCI PIPING From Reference 1, the basic equation describing heat flow into each segment of pipe is AT 4"

IRTHERMAL For each segment of pipe, there are three separate thermal resistances. These are modeled in figure 4.

FIGURE 4: ANALYTICAL MODEL OF PIPING. SHOWING HEAT FLOW OUT fouT flN R.

IN Ri R is the thermal resistance to convective heat transfer from the HPCI room atmosphere to the outer wall of the pipe. R is the therm.:1 resistance to conductive heat flow through the wall of the pipe. R is the resistance to convective heat transfer from the inner wall of i

the pipe to the water flowing within the pipe. r,,and ri, are, respectively, the outer and o

inner radii of the pipe.

As discussed above, condensation heat transfer is assumed to take place by convection between leaking steam in the HPCI room and the outside walls of the pipes. Then, heat flows by conduction through the wall of the pipe. Finally, heat is transferred by convection to the water on the inside of the pipe. Thus there are three separate thermal resistance values to be determined for the various segments of piping.

Carolina Power & Light Company, BNP ESR 9600148

. Temperature EfTects of HPCI Gland Seal Exhauster Failure Revision 0. Page 11 of 31 3.4 ANALYTICAL MODEL OF HPCI PIPING (continued)

Thermal resistance will be determined for each segment of piping. From Reference 1, the components of thermal resistance shown in figure 4 may be determined as follows:

In( "ro)

I I

Ro = ho

Ao Rw =

Ri = hi

Ai 2'n*k*L

Where, h,

the convective heat transfer coefficient between the HPCI room

=

and the wall of the pipe.

h, the convective heat transfer coefficient between the wall of the

=

pipe and the water flowing through the pipe.

k

=

the thermal conductivity of the piping material (SS or CS)

A, the outside surface area of the pipe

=

A, the inside surface area of the pipe

=

L

=

the length of the pipe being evaluated.

THERMAL CONDUCTIVITY OF HPCI ROOM PIPING Two piping materials are used in the HPCI toom. Part of the suction piping is stainless steel, which has a thennal conductivity of approximately 10 BTU /hr ft *F and part of the suction piping is carbon steel, which has a thermal conductivity of approximately 25 BTU /hr ft *F (Reference 2). The crossover piping, the discharge piping, and the pumps are carbon steel and have a thermal conductivity of approximately 25 BTU /hr ft *F.

CONVECTIVE HEAT TRANSFER COEFFICIENTS The most difficult parameter to estimate is h, the convective heat transfer coefficient o

between the HPCI room and the outside surface of the pipes. This is because the value 2

for h, may be as low as I to 10 BTU /hr ft *F for free convection in air, or as great as 2

1,000 to 20,000 BTU /hr ft F for condensation heat transfer (Reference 1). Appropriate values for h, and hi were determined analytically in appendix 1.

]

As shown in appendix 1, the condensing convective heat transfer coefficient. h,,, at the 2

outside of the pipes is 697 BTU /Hr ft F. If the HPCI room is treated as a pure control volume, the average convective heat transfer coefficient at the pipes and walls will be 2

assumed to be 174 BTU /hr ft *F (appendix 1). The convective heat transfer coefficient, 2

h, inside the pipes, ranges from approximately 1.000 to 3,000 BTU /Hr-ft - F.

i

a u

)

Carclina Power & Light Company, BNP ESR 9600148 Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Page 12 of 31 3.5 ANALYTICAL MODEL OF HPCI ROOM WALLS From Reference 1, the basic equation describing heat flow through a wall is:

AT 9"

IRTHERMAL For each section of wall or ceiling, there are three separate thermal resistances. These are modeled in figure 5.

FIGURE 5: ANALYTICAL MODEL OF HEAT TRANSFER THROUGH A WALL Tiu Ri /

R

/o R. '

OUT L

Heat transfer takes place by convection between the HPCI room and the inside wall.

Then, heat flows by conduction through the wall. Finally, heat is transferred by convection to the space on the outside of the wall. Thus, there are three separate thermal resistance values to be determined for each inside wall or the ceiling. From Reference 2, the components of thermal resistance may be determined as follows:

1 Ri =

Rw =

i Ro =

hl

Aw k*Aw ho

Aw

Where, h,

the convective heat transfer coefficient between the HPCI room

=

and the wall.

h.

the convective heat transfer coefficient between the wall and

=

the RHR room or the area above the HPCI toom.

k

=

the thermal conductivity of the concrete wall.

Aw the surface area of the wall.

=

L

=

the thickness of the wall.

,m.

Carolina Powtr & Light Company, BNP ESR 9600148 Temperature Effects ofIIPCI Gland Seal Exhauster Failure Revision 0. Page 13 of 31 4.0 CASE #1 SIMPLE CONTROL VOLUME 4.1 HEAT TRANSFER MODEL As discussed in section 3.2.1, this evaluation will assume that the HPCI room can be treated as a control volume. The model for this evaluation is shown below.

System Heat Losses HPCI ROOM Conduction Through Walls and Ceiling Steam Leaks In Room N

/

N Heat Removed By Water N

Flowing Through

+ Un-insulated Segments of Piping in HPCI Room In this model, heat is assumed to be transferred out of the HPCI room a) through pipes with cool water flowing in them, b) through the ceiling to the area above the HPCI room, c) through the end walls at the North and South ends of the HPCI room into the RHR rooms, and d) through the East wall into the earth.

The temperature in the HPCI pipes is assumed to be 90 F. This is based on discussions with the system engineer. Based on Reference 4, the temperature of the RHR rooms and the area above the HPCI toom is assumed to be 104 F. The temperature of the earth outside the East wall is assumed to be 70*F. No credit will be taken for RHR room cooler operation, which has the capability to remove 210.000 BTU /Hr (see assumption 2.3).

r-Carolina Power & Light Company, BNP ESR 9600148

. Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Page 14 of 31 4.1 HEAT TRANSFER MODEL (continued)

At steady-state temperature, the heat flowing out of the room will equal the heat flowing into it. Therefore, qSYSTEM + qLEAKS E QPIPINC + QCEILING+ QENO WALLS + qEASTWALL According to Reference 1, the basic expression for heat transfer may be expressed as:

ATi 9' "

IRTHERMAL-l For each heat transfer mechanism this may be substituted into the previous equation.

Also, the thermal resistances can be determined by analytical means. Therefore, since AT is related to HPCI room temperature the resultant equation can be solved numerically to determine the HPCI room temperature when heat flow is at equilibrium.

In order to do this, the thermal resistances of each component must first be determined.

I Carolina Power & Light Company, BNP ESR 9600148

. Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0, Page 15 of 31 4.2 DETERMINATION OF THERMAL RESISTANCES 4.2.1 HPCI PIPING Thermal resistance of each segment of HPCI piping can be determined from the equations provided in section 3.4. The tables below show the relevant physical parameters of each segment of pipe and the resultant calculated values for thermal resistance. Note that the values for convective heat transfer coefficients and the values for piping lengths and areas are taken from appendices I and 2, respectively.

SUCTION PIPING PARAMETER STAINLESS STEEL SECTION CARBON STEEL SECTION ID, INCHES 16.000 16.000 THICKNESS. INCHES 0.188 0.375 OUTSIDE h. BTU /HR-FT' *F 174 174 OUTSIDE AREA. FT' 62.11 79.21 Roursa 9.253 E-5 7.255 E-5 LENGTH, FEET 14.828 18.911 THERMAL CONDUCTIVITY, 10 25 BTU /HR-FT *F Rwatt 2.5525 E-5 1.616 E 5 INSIDE h. BTU /HR-FT' *F 1.903 1,986 lNSIDE AREA 60.65 75.50 Riusa -

0.8662 E-5 0.667 E 5 TOTAL Rmenuat 12.67 E 5 9.538 E 5 1/ Rmenet 7,892 10,484 i

PUMPS AND DISCHARGE PIPING PARAMETER CROSSOVER PUMPS DISCHARGE ID. INCHES 12.00 24 12.124 THICKNESS. INCHES 0.375 1

0.938 OUTSIDE h. BTU /HR-FT' 'F 174 174 174 l

OUTSIDE AREA. FT' 71.24 37.70 155.86 j_

Roursa 8.067 E 5 15.245 E-5 3.687 E 5

]

LENGTH FEET 21.344 6

42.524

k. BTU /HR-FT *F 25 25 25 Rwatt 1.808 E 5 9.232 E-5 2.154 E 5 INSIDE h. BTU /HR-FT' *F 3.021 1.045 2.967 j

INSIDE AREA 67.05 34.56 134.97 j

R,Nsm 0.4937 E 5 2.767 E-5 0.2497 E 5 TOTAL Rmenuit 10.37 E-5 27.24 E 5 6.091 E-5

}

1/ Rmenet 9,643 3.671 16.418

1.

Carolin0 Power & Light Company, BW ESR 9600148

. Temperature Effects of HFCI Glr.d Seal Exhauster failure Revision 0. Page 16 of 31 4.2.2 HPCI ROOM CEILING Thermal resistance of the HPCI room ceiling can be detennined from the equations prerided in section 3.5. The table below shows the relevant physical parameters of each cornponent of the thermal resistance of the ceiling. Note that the values for convective heat transfer coerTicients and the values for thickness and areas are taken from appendices 1 and 3, respectively.

INSIDE h. BTU /HR-FT' 'F 174 AREA. FT' 1,700 R,ss a 0.338 E 5 THICKNESS FEET 3

THERMAL CONDUCTIVITY. BTU /HR-FT *F 0.7 (Ref. 2)

Rwatt 252.1 E 5 OUTSIDE h. BTU /HR-FT' 'F 1

AREA 1,700 Rourson 58.82 E-5 TOTAL Rmenu4t 3.113 E 3 1/ Rmenuat 321 4.2.3 HPCI ROOM END WALLS (TO RHR ROOMS) i Thermal resistance of the HPCI room end walls can be determined from the equations provided in section 3.5. The table below shows the relevant physical parameters of each component of the thermal resistance of the walls. Note that the values for convective heat transfer coefficients and the values for thickness and areas are taken from appendices 1 and 3, respectively.

INSIDE h, BTU /HR-FT' *F 174 AREA, FT' 1,292 R,ysee 0.4448 E 5 THICKNESS. FEET 2

THERMAL CONDUCTIVITY, BTU /HR-FT *F 0.7 Rwitt 221.1 E-5 OUTSIDE h, BTU /HR FT' 'F 1

AREA 1,292 Rourson 77.40 E-5 TOTAL benu4t 2.99 E 3 1/ Rmenuat 334

{

Carolina Power & Light Company, BNP ESR 9600148

. Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Page 17 of 31 4.2.4 HPCI ROOM EAST WALL (TO EARTID Thermal resistance of the HPCI room east wall can be determined from the equations provided in section 3.5. The table below shows the relevant physical parameters of each component of the thermal resistance of the walls. Note that the values for convective heat transfer coefficients and the values for thickness and areas are taken from appendices 1 and 3, respectively. Note also that the temperature of the outside wall is assumed to be maintained at constant temperature by the ground. Thus, a convective heat transfer coefficient is not determined for the outside wall.

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INSIDE h. BTU /HR-FT' 'F 174 AREA. FT' 950 R,%ee 0.6049 E-5 THICKNESS. FEET 4

THERMAL CONDUCTIVITY, 0.7 BTU /HR-FT *F Rwatt 601.5 E 6 TOTAL Rmenet 6.021 E-3 1/ Rmenet 166.1 4.3 TOTAL HEAT LOAD According to Reference 8. the enthalpy of saturated steam at 1,020 psia is 1I ?2.2 BTU /Lb. For the purpose of estimating how much heat is released to the HPCl room,it will be assumed that the steam which leaks past the turbine seals condenses anc cools to 100 F. According to Reference 8. the enthalpy of water at this temperature is 68 BTU /Lb. Therefore. if 345 pounds of steam are released in one hour, the heat input to the HPCI room is 387,849 BTU /Hr. Adding in the normal heat load (130.630 BTU /Hr), the total heat load in the HPCI room control volume is 518.479 BTU /Hr.

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1 Carolina Powtr & Light Company, BNP ESR 9600148 Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Page 18 of 31 4,4 EOUILIBRIUM TEMPERATURE At equilibrium temperature, the sum of the various heat removal mechanisms discussed above will equal the heat flow into the HPCI room. It is assumed that the temperature inside the HPCI piping is 90*F. the temperature in the RHR rooms (outside the end walls and ceiling) is 104*F, and the temperature of the ground outside the east wall is 70'F.

Therefore, at equilibrium, the heat transfer from the HPCI room, for each mechanism discussed above, is given by:

ATPIPE ATPIPE ATPIPE ATPIPE 9,

IRsucT ss IRsucrcs IRcRossovER IRPUuFs ATPIPE ATcEiuNG ATENL5 AIEAST WALL IRDisCHARGE IRCEILING IREND WALLS IREAsT WALL

~

1 1

1

= (TRoom - TPIPE)

+

IRsucT-ss IRsucT cs IRCRossoVER IRPuMPs IRoisCHARGE TRoou -TRHR TRoou - TRHR,

TRooM - TGRouND i

IRCEILING IREND WALLS IREAsT WALL 1

1 1

~

= (TRoom - 90) 12.67 E-5 9.54 E-5 10.37 E-5 27.24 E 5 6.09 E-5 TRooM - 104 TRoom - 104 TRoou - 70 3.113 E-3 2.99 E-3 6.021 E-3 518,479 BTUIHR

=

Solving the above equation numerically to determine Taooy, it is seen that the I

equilibrium temperature in the HPCI room will be approximately 101 F.

Therefore, if the HPCI room behaves as a control volume. with a homogeneous distribution of heat the maximum temperature is not expected to be great enough to cause thermally induced pressure locking of the HPCI suction valves.

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a Carolina Powe7 & Light Company, BNP ESR 9600148

. Temperature Effects of HPCI Gland Seal Exhauster failure Revision 0. Page 19 of 31 5.0 CASE C MODIFIED CONTROL VOLUME 5.1 HEAT TRANSFER BY CONDENSING STEAM As discussed in section 3.2, condensatbn heat transfer is assumed to take place on those portions of the HPCI piping with flow through them. In this model, the only convection / conduction heat transfer which takes place is for condensation on the HPCI pumps and piping. All remaiaing heat removal is accomplished by heating the air supplied by the RHR room coolers. No credit is taken for heat removal by convection / conduction through the walls or ceiling, by un-condensed steam being removed via air flow, or by hot, condensed liquid being removed from the room via the HPCI room sump. The maximum air temperature determined for this model will be assumed to be the temperature at the HPCI suction valves.

From section.V ;he heat transfer into a segment of the HPCI piping may be expressed as:

ATi qi =

IRTHERMAL-!

Therefore, the total heat into all segments of the HPCI piping may be expressed as:

AT AT AT AT AT qc IRsucr.ss IRsucr.cs IRcRossovER IRPuMPs IRDisCHARGE The total heat flow, q. can be determined from the assumed enthalpy change as the leaking steam condenses, and the thermal resistances can be determined from the piping geometry and the information provided in cppendices 1 and 2. The above equation can 4

then be solved for AT.

5.1.1 HEAT RELEASED BY CONDENSING STEAM The enthalpy of the steam supplied to the HPCI turbine is 1192.2 BTU /Lb (saturated steam at 1,020 psia. Reference 8). It is assumed to become liquid at 212 F by condensation on the walls of the HPCI piping. From Reference 8. the enthalpy of the saturated liquid is 180.2 BTU /I b. Thus, the net heat transfered to the walls of the pipe by condensation is 1.012 DTU/Lb. Therefore. for a steam Ic.tk of 345 LB/Hr. the total heat transferred by condensation is 349.140 BTU /Hr.

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Carolina Power & Light Company, BNP ESR 9600148

. Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Paec 20 of 31 5.1.2 THERMAL RESISTANCE OF HPCI PIPING Under conditions of condensing heat transfer, the thermal resistance of each segment of HPCI piping can be determined from the equations provided in section 3.4 and information provided in Appendices 1 and 2. The tables below show the thermal

. resistances of each segment of pipe.

'3EGMENT SUCTION SUCTION

-+

fARAMETER 1 SS CS OUTSIDE AREA, FT' 62.11 79.22 OUTSIDE h, BTU /HR-FT' *F 697 697 Rourna 2.31 E 5 1.81 E 5 l

l OUTSIDE DIAMETER, INCHES 16.000 l 16.000

~

INSIDE DIAMETER, INCHES 15.624 15.25 LENGTH, FEET 14.828 18.911 THERMAL CONDUCTIVITY, BTU /HR-FT 'F 10 25 l

Rwau 2.55 E 5 1.62 E-5 INSIDE h, BTU /HR-FT' 'F 1,903 1,966 INSIDE AREA 60.65 75.50 R es 0.866 E 5 0.667 E-5 TOTAL Rrwennt 5.726 E 5

' 4.097 E-5 il Rywennt 17,456 2d.424 SEGMENT

CROSSOVER PUMPS DISCHARGE PARAMETER 1 OUTSIDE AREA, FT' 71.24 37.70 155.86 l

OUTSIDE h, BTU /HR-FT' *F 697 697 697 Rours,y 2.01 E 5 3.81 E 5 0.921 E 5 OUTSIDE DIAMETER. INCHES 12.75 24.00 14.00 INSIDE DIAMETER, INCHES 12.00 22.00 12.126 LENGTR FEET 21.344 6.00 42.524

~

THERMAL CONDUCTIVITY, BTU /HR-FT 'F 25 25 25 Rwau 1.81 E-5 9.23 E-5 2.15 E 5 INSIDE h BTU /HR FT'."F 3,021 1,046 2,Pa7 l

INSIDE AREA 67.05 34.56 13+ 7 l

Rwsme 0.494 E-5 2.77 E-5

{ 0.250 E-5 1

3 TOTAL Rrwemmt 4.314 E-5 15.81 F 5 3.321 E-5 l

11 Rvsenet 23,171 6.327 30,083 l

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l Carolina Power & Light Company, BNP ESR 9600148

. Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0, Pace 21 of 31 l

5.1.3 TEMPERATURE OF HPCI PIPING As shown above, the total heat flow is equal to:

AT AT AT AT AT q,

IRSucT-ss IRsucT-cs IRCROssOVER IRPUMPs IRDISCHARGE Therefore, the differential temperature from the outside to the inside of the pipe is equal to:

9 AT =

1 1

1 IRsucT-ss IRsuct-cs IRcRossoven IRPUMPs IRDISCHARGE 349,140 F

3.4 *F

=

l 101,461 This indicates that condensing steam on the HPCI piping would result in only a slight increase in the surface temperature of the pipes. When one considers that the flow in the l

HPCI piping is greater than 2,000.000 pounds per hour, the net increase in HPCI fluid l

temperature would be less than 0.2 F. The conclusions are:

1)

The un-insulated piping and pumps have adequate heat removal capacity to condense the leaking steam 2) the effects on the HPCI process temperature will be very slight.

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)

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5, Carolina Power & Light Company, BNP ESR 9600148

{

. Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Pace 22 of 31 1

5.2 HEAT TRANSFERRED TO THE HPCI ROOM AIR After the steam condenses, the remainder of the heat released by the liquid as it cools to l

room temperature is assumed to be transferred exclusively to the air in the HPCI room.

The final, steady-state air temperature is assumed to constitute the environment around i

the suction valves.

]

According to Reference 4, Section 4.4.2.5, the coil temperature of the RHR room coolers may be as great as 97.4*F. Assume that the heat released per pound ofliquid is equal to the temperature change from 212*F to 97.4*F, or 114.6 BTU /Lb. For a steam leak of 345 Lb/Hr, this results in 39,537 BTU /Hr added to the heat released into the air. As discussed in section 3.1, the total normal heat load of the room is 130,630 BTU /Hr. Therefore, the net heat assumed to be added to the air is 170,167 BTU /Hr.

1 The air flow into the HPCI room is 3.980 scfm (Reference 13) via the RHR room coolers.

No credit is taken for the Reactor Building HVAC system which normally supplies 3,400 3

i scfm to the HPCI room. Since the air density at 100 F is 0.071 Lb/ft (Reference 3), the mass flow through the HPCI room is 16.955 LB/Hr. According to Reference 2. the heat j

capacity of air is 0.240 BTU /Lb-F. Therefore, the temperature rise of air as it flows through the HPCI room is 170,167 BTUlHr j

AT =

= 41.8 F 16,955 LB/Hr

0.24 BTUILb *F i

If the initial temperature of the air is 97.4*F, the maximum temperature of the air exiting the HPCI room is 139'F.

Therefore, the maximum temperature is not expected to be great enough to cause thermally-inducea pressure locking of the HPCI suction valves.

Carolint Power & Light Company, BNP ESR 9600148 Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Page 23 of 31 6.0 DISCUSSION OF RESULTS In the models analyzed above, the maximum expected temperature in each HPCI room is determined to be less than 140*F after failure of a HPCI Gland Seal Exhauster (GSE). In order to analyze each model, several assumptions were required. It is believed that the assumptions were conservative. In each model, significant mechanisms of heat removal were not credited, in order to achieve a conservative result.

One of the most significant assumptions, and potential sources of error, is the value for convective / condensing heat transfer. Here also, a conservative approach was taken by dividing the calculated value in half when analyzing the room by the control volume model. It is noted that the calculated value for average h can be reduced by an order of magnitude and the calculated temperature in the HPCI room would still not reach unacceptable levels.

It is understood that direct impingement of a steam leak on a suction valve would have a significantly greater localized heating effect than the temperatures calculated in either model. However, due to the location of the suction valves. the turbines. and the pumps and piping, direct impingement ofleaking steam on a suction valve is not considered credible.

A review of similar analyses in the Reactor Building Environmental Report (Reference 6) determined that a HPCI steam line break could increase the temperature in the HPCI room to approximately 295 F for a brief period of time (< 10 minutes). By contrast, the analyzed LOCA condition is expected to produce a maximum HPCI room temperature of t

approximate!y 133*F. Both of these analyses support the conclusion that there is significant capability for heat removal from the HPCI rooms.

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Car: lins Power & Light Company, BNP ESR 9600148 Temperature Effects of HPCI Gland Seal Exhauster Failere Revision 0. Page 24 of 31 7.0

SUMMARY

AND CONCLUSIONS In this analysis, it has been concluded that the maximum temperature expected in the HPCI rooms, after a failure of a Gland Seal Exhauster, is less than 140*F. The information in Reference 12 indicates that somewhat greater temperatures (approaching 200*F) are generally necessary before thermally-induced pressure locking occurs. For the initial pressure locking and thermal binding review (Reference 10), it was assumed that lower temperatures, in the region of 150*F to 175 F, might have the potential to create thermally-induced pressure locking. Reference 10 was a qualitative evaluation which was intended to be conservative. Based on the evaluations in sections 4.0 and 5.0, it is concluded that thermally-induced pressure locking is not expected to occur in the HPCI suction valves.

Therefore, the HPCI suction valves are acceptable in their present configuration and no modifications or further actions are recommended.

Carolins Pow:r & Light Company, BNP ESR 9600148 Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Page 25 of 31

8.0 REFERENCES

1 Fundamentals of Momentum. Heat and Mass Transfer, by Welty, Wicks, and Wilson.

2.

Heat Transfer, by J. P. Holman second edition.

3.

HVAC Systems, Testing, Adjusting, and Dalancing, second edition.

4.

Design Basis Document DBD-37.1, Reactor Building Ventilating System, rev.1.

3.

Calculation 8S42-M-03, revision 1, Station Blackout - Loss of HVAC, by NUS, dated 5/22/91.

6.

Reactor Building Environmental Report, 7.

System Description SD-37.1 8.

1967 ASME Steam Tables 9.

Crane Technical Paper 410. 24th printing.

10.

ESR 960114, revision 0.

I 1.

0-FP-05369, revision A HPCI Steam Seal Piping Diagram 12.

NUREG-1275. Volume 9. Operating Experience Feedback Report - Pressure Locking and Thermal Binding of Gate Valves 13.

F-04073, sheet 1, revision 6. Reactor Building Ventilation System Air Flow Diagram, Unit No. 2.

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Carolin: Powtr & Light Company, BNP ESR 9600148 Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Page 26 of 31 APPENDIX 1 DETERMINATION OF CONVECTIVE HEAT TRANSFER COEFFICIENTS t

1.

CONDENSATION HEAT TRANSFER ON OUTER WALL OF PIPE According to Reference 2 page 302. equation 9-10, the average convective heat transfer coetTicient ior condensing vapor on a tube (or pipe) may be determined by a relationship expressed by Nusselt as:

' il4

' p, (p, - py)

g

h,g

k,8

-h=

0.725 l

p,

d * (T - Tw) o

Where, 2

(59.9 Lbm/ft')2 pf (pf - pv) pf

=

pf density of fluid (hquid)

=

density of vapor pv

=

2 2

2 32.2 ft/sec * (3600 sec'/hr )

g

=

hfg 970.3 BTU /Lbm, heat of vaporization. This is a simplifying

=.

assumption, since the leaking steam will actua:ly not be saturated vapor at 212*F k

=

0.393 BTU /Hr-ft *F, liquid thermal conductivity 0.693 Lbm/ft-hr. liquid viscosity p

=

d

=

the diameter of the pipe, in feet. The most conservative approach is j

to use the largest diameter, which is 16 inches, or 1.333 feet.

Tg The temperature of saturated vapor, which is assumed to be 212*F.

=

Tw The temperature of the outside wall of the pipe. This will

=

I be assumed to be equal to 100*F.

i Therefore, the average convective heat transfer coefficient for condensation may be estimated as:

2 2*

3 '

l 59.9

32.2

3600 970.3

0.393 h=

0.72.5 0.693

1.33

112 697 BTblHr-ft,op 2

=

Reference 2 indicates that this relationship is generally conservative by approxi

.cly 20%.

i

Carolina Power & Light Company, BNP ESR 9600148 Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Page 27 of 31 APPENDIX 1 DETERMINATION OF CONVECTIVE HEAT TRANSFER COEFFICIENTS (cont'd) 2.

CONVECTIVE HEAT TRANSFER AT INNER WALL OF PIPE According to Reference 2, by combining equations 5-72 and 5-73, the convective heat transfer coefficient inside piping may be determined by:

h = p

Cp

VEL

0.316

8.

Re*

Where, density, which is 62.1 lb/ft3 p

=

C, 0.997 BTU /Lbm

=

VEL

=

velocity of fluid In the HPCI piping, flow is assumed to be approximately 4,250 gpm at a temperature of 90*F. According to Reference 9, equation 3-3 on page 3-2, Reynold's number may be determined by:

R. = 50.6 FLOW (GPM)

DENSITY (LBIFT3)

DlAMETER (INCHES)

VISCOSITY (CENTIPOISE)

At an internal temperature of 90*F. viscosity is 0.73 centipoise and the density is approximately 62.1 Lb/ft). The table below shows the value for the convective heat transfer coefficient in each section of pipe for a flow rate of 4.250 gpm.

1 SEGMENT

SS SUCTION CS SUCTION CROSSOVER PUMPS DISCHARGE PARAMETER 1 INSIDE DIAMETER, INCHES 15.624 15.25 12.00 22.00 12.126

VELOCITY, FT/SECOND 7.11 7.47 12.06 3.59 11.81 REYNOLD'S NUMBER 1,170,890 1,199,605 1,524,498 831,545 1,508,906 INSIDE h, BTUIHR FT* *F 1,903 1,986 3,021 1,046 2,967 l

Carolina Power & Light Company, BNP ESR 9600148

. Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Page 28 of 31 APPENDIX 1 DETERMINATION OF CONVECTIVE HEAT TRANSFER COEFFICIENTS (cont'd) 3.

CONDENSATION HEAT TRANSFER ON HPCI ROOM WALLS According to Reference 2, combining equations 9-7 and 9-9 (see page 278), the average convective heat transfer coefficient for condensing vapor on a vertical surface may be determined by:

p,

g

hrg

k,3 h=

1.33 4*

l. * (Tg - T,)

Where, 2

(59.9 Lbm/ft')2 pf (pf - pv) pf

=

2 2

2 32.2 ft/sec. (3600 sec /hr )

g

=

i hfg 970.3 BTU /Lbm. This is a simplifying assumption, since the

=

i eaking steam will actually not be saturated vapor at 212*F

]

l k

=

0.393 BTU /Hr-ft 'F

)

0.693 Lbm/ft-hr j

=

l L

the height of the wall, in feet. The HPCI room is 19 feet high

=

(F-1108, revision 8).

Tg The temperature of saturated vapor, which is assumed to be 212'F.

=

Tw The temperature of the wall. This will be assumed to be 100'F.

=

Therefore, the average convective heat transfer coefficient for condensation may be estimated as:

'i4

'59.9 2

32.2

36002

970.3

0.393 h=

1.33 4

19

0.693

112 2

465 BTUIHr-ft,op

=

v Carolino Power & Light Company, BNP ESR 9600148 Temperature Effects of HPCI Gland Seal Exhausterfailure Revision 0, Page 29 of 31 APPENDIX 1 DETERMINATION OF CONVECTIVE HEAT TRANSFER COEFFICIENTS (cont'd) 4.

HEAT TRANSFER BY FREE CONVECTION AT WALLS OF ROOM The walls of the HPCI and RHR rooms may be modeled as vertical, flat surfaces and the ceiling may be modeled as a horizontal flat surface. Reference 2 provides guidance for analytically determining the respective convective heat transfer coefficients. However, by inspection, uch surface has unique geometrical features, such as piping attachments and structural components. These features cause the geometry of the walls and ceiling to deviate from simple, flat surfaces. Also, air is forced through the rooms, either by the normal HVAC system or by the RHR room coolers. These conditions combine to create significant differences between the actual surfaces and the smooth, un-disturbed surfaces assumed in Reference 2.

Reference 1 provides tabular guidance which indicates that the convective heat transfer coefficient for free convection in air is in the range of 1 to 10 BTU /Hr-Ft - F.

Accordingly, instead of analyzing each surface for the expected free convection heat z

transfer coefficient, a value of 1 BTU /Hr-Ft *F will be assumed. For conservatism, the minimum value in the " typical" range will be assumed.

5.

AVERAGE CONVECTIVE HEAT TRANSFER COEFFICIENT If the HPCI room is treated as a strict control volume, then a single value for the convective heat transfer coetTicient is desirable. From the calculations in Section 4.3 and Sections 1 and 3 of this appendix, it is seen that approximately 75% of the heat transfer in 2

the occurs at a value of h of 465 BTU /Hr-Ft - F or greater. The remaining 25% occurs 2

at a value of h which is approximately equal to 1 BTU /Hr-Ft *F. Therefore, an estimate of the " average" value for h is:

h, =i 0.75

465 + 0.25

1 = 349 BTU /IIr-Ft *F o

It is recognized that this is a coarse estimate. For conservatism. a value of 1/2 of the 2

average value for h. or 174 BTU /Hr-Ft - F. will be assumed when treating the HPCI room as a control volume.

Car: lina Power & Light Company, BNP ESR 9600148 Temperature Effects of HPCI Gland Seal Exhauster failure Revision 0. Page 30 of 31 APPENDIX 2 TABULATION OF PIPING LENGTHS AND EFFECTIVE AREAS Within the HPCI room, there are four segments of pipe with flow in them. The two pumps will be assumed to constitute a fifth segment of piping, and will be modeled as two lengths of 24-inch pipe,3 feet long each. with 1-inch thick walls. The lengths of each segment of pipe were determined by adding the lengths of the individual sections.

The bases for each determination are shown below.

1 REFERENCE SEGMENT LENGTH OF SEGMENT DRAWINGS SS SUCTION PIPING 14.828 FEET FSP-2712, SH.10 CS SUCTION PIPING 18.911 FEET 2-FP-60033 l

CROSSOVER PIPING 21.344 FEET FP-05303 DISCHARGE PlPING 42.524 FEET 2-FP-60034 &

D-02593 The relevant dimensions and parameters of each segment of pipe are shown in the table below:

ID, THICKNESS.

THERMAL INSIDE OUTSIDE SEGMENT INCHES INCHES CONDUCTIVITY AREA. FT' AREA. FT' SUCTION, SS 15.624 0.188 10 60.65 62.11 SUCTION, CS 15.25 0.375 25 75.50 79.22 CROSSOVER 12.000 0.375 25 67.05 71.24 DISCHARGE 12.126 0.937 25 134.97 155.86 PUMPS 22 1

25 34.56 37.70

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Carolina Power & Light Company, BNP ESR 9600148

. Temperature Effects of HPCI Gland Seal Exhauster Failure Revision 0. Page 31 of 31 APPENDIX 3 TABULATION OF WALL THICKNESSES AND AREAS EAST WAIL PARAMETER DIMENSION REFERENCE DRAWING LENGTH, FT 50 F-25001, Revision 16 THICKNESS, FT 4

F-25001, Revision 16 HEIGHT, FT 19 F-25001, Revision 16 NET AREA, FT*

950 CFII ING PARAMETER DIMENSION REFERENCE DRAWING LENGTH, FT 50 F-25001, Revision 16 THICKNESS, FT 3

F-1108, Revision 8 WIDTH, FT 34 F-1108, Revision 8 8

NET AREA, FT 1,700 END WALLS. (NORTH & SOUTH)

PARAMETER DIMENSION REFERENCE DRAWING HEIGHT, FT 19 F-1108, Revision 8 THICKNESS, FT 2

F-1101, Revision 14 WIDTH, FT 34 F 1108, Revision 8 8

i NET AREA, FT 1,292 l

As discussed in Assumption 2.8, no heat transfer is assumed to to take place from the HPCI room through the West wall into the Suppression Pool.

I ENCLOSURE 3 BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 NRC DOCKET NOS. 50-325 AND 50-324 OPERATING LICENSE NOS. DPR-71 AND DPR-62 RESPONSE TO NRC GENERIC LETTER 95-07, " PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES "

SIGNIFICANT VALVE MODIFICATIONS PERFORMED PRIOR TO GENERIC LETTER 95-07 VALVE VALVE FUNCTION MODIFICATIONS & REVISIONS 1/2-821-F016 MAIN STEAM LINE DRAIN Replaced Flex-Wedge Valve with Double-Disc Valve. Added ISOLATION Bonnet Pressure Equalizing Valves.

1/2-B21-F019 MAIN STEAM LINE DRAIN Replaced Flex-Wedge Valve with Double-Disc Valve. Added ISOLATION Bonnet Pressure Equalizing Valves.

1/2-E11-FOO4A RHR PUMP TORUS SUCTIONS Drilled Hole in Disc, Added General Precaution in Operating 1/2-E11-FOO4B Procedure 1/2-E11-FOO4C 1/2-E11-FOO4D 1/2-E11-F015A RHR LPCI INJECTION Drilled Hole in High-Pressure Disc 1/2-E11-FO15B RHR LPCI INJECTION Drilled Hole in High-Pressure Disc 1/2-E21-FOO5A CORE SPRAY INJECTION Drilled Hole in High-Pressure Disc 1/2-E21-FOO5B CORE SPRAY INJECTION Drilled Hole in High-Pressure Disc E3-1

k VALVE VALVE FUNCTION MODIFICATIONS & REVISIONS 1/2-E41-F001 HPCI TURBINE STEAM ADMISSION Replaced Flex-Wedge Valve with Double-Disc Valve, Drilled Hole in High Pressure Disc, installed a Ball-Screw Actuator 1/2-E41-F002 HFCI INBOARD STEAM ISOLATION Replaced Flex-Wedge Valve with Double-Disc Valve. Added VALVE Bonnet Pressure Equalizing Valves.

1/2-E41-F003 HPCI OUTBOARD ~ STEAM Replaced Flex-Wedge Valve with Double-Disc Valve. Added ISOLATION VALVE Bonnet Pressure Equalizing Valves.

1/2-E41-FOO6 HPCI INJECTION VALVE Replaced Flex-Wedge Valve with Double-Disc Valve, Drilled Hole in Feedwater-Side Disc, Installed Ball-Screw Actuator 1/2-E51-F007 RCIC INBOARD STEAM ISOLATION Replaced Flex-Wedge Valve with Double-Disc Valve. Added Bonnet Pressure Equalizing Valves.

1/2-E51-FOO8 RCIC OUTBOARD STEAM Replaced Flex-Wedge Valve with Double-Disc Valve. Added ISOLATION Bonnet Pressure Equalizing Valves.

1/2-E51-F013 RCIC INJECTION VALVE Replaced Flex-Wedge Valve with Double-Disc Valve, Drilled Hole in Feedwater Side Disc 1/2-G31-FOO1 RWCU INBOARD SUCTION Replaced Flex-Wedge Valve with Double-Disc Valve, Drilled Hole ISOLATION in Reactor Side Disc 1/2-G31-F004 RWCU OUTBOARD SUCTION Replaced Flex-Wedge Valve with Double-Disc Valve, Drilled Hole ISOLATION in Reactor Side Disc E3-2

ENCLOSURE 4 BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 NRC DOCKET NOS. 50-325 AND 50-324 OPERATING LICENSE NOS. DPR-71 AND DPR-62 RESPONSE TO NRC GENERIC LETTER 95-07, " PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES "

LIST OF REGULATORY COMMITMENTS The following table identifies those actions committed to by Carolina Power & Light i

Company in this document. Any other actions discussed in the submittal represent intended or planned actions by Carolina Power & Light Company. They are described to the NRC for the NRC's information and are not regulatory commitments. Please notify the Manager-Regulatory Affairs at the Brunswick Nuclear Plant of any questions regarding this document or any associated regulatory commitments.

Committed Commitment date or outage None N/A l

E4-1

_ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

BSEP-96-0225, Forwards Response to NRC GL 95-07, Pressure Locking & Thermal Binding of Safety-Related Power-Operated Gate Valves

Contents

Text

Enclosures:

Reference:

Reference:

Reference:

SUMMARY

1.0 BACKGROUND

1.1 BACKGROUND

SUMMARY

8.0 REFERENCES

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BSEP-96-0225, Forwards Response to NRC GL 95-07, Pressure Locking & Thermal Binding of Safety-Related Power-Operated Gate Valves

Text

Enclosures:

Reference:

Reference:

Reference:

SUMMARY

1.0 BACKGROUND

1.1 BACKGROUND

SUMMARY

8.0 REFERENCES

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