ML20247G655

Forwards Response to NRR Questions Re Plant Tech Specs Concerning Instrumentation & Control Circuits Associated W/ Reactor Trip Sys,Esf Sys & Accident Monitoring

ML20247G655
Person / Time
Site:	Comanche Peak
Issue date:	05/15/1989
From:	William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
TXX-89233, NUDOCS 8905310037
Download: ML20247G655 (9)

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=, Log # TXX-89233 1 C File # 916

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~ nlELECTRIC waism J. cam,Jr.

May 15, 1989 Executive Vice President U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)

DOCKET N05.-50-445 RESPONSE'TO NRR QUESTIONS PERTAINING TO THE CPSES TECHNICAL SPECIFICATIONS

-Gentlemen:

During NRR review of the CPSES Technical Specifications, NRR verbally requested additional information pertaining to. instrumentation and control circuits associated with the Reactor Trip System, Engineered Safety Features System and Accident Monitoring Technical Specifications. On March 22, 1989, TV Electric contacted NRR (F. Ashe) _for clarification of the questions.

Attached is the list of NRR questions and TV Electric responses.

Sincerely,

$#L (M

William J. Cahill, Jr.

/

VPC/ddm Attachments c.- Mr. R. D. Martin, Region IV Resident Inspectors, (CPSES) (3) 8905310037 890535 .

NA 4 PDR ADOCK 05000445 ,1 A PDC l

400 North Olive Street LB81 Dallas, Texas 75201

Attachment 1 to TXX-89233 May 15, 1989 o

'Page 1 of 4 NRR Request for Additional Information Pertaining to the CPSES Technical Specifications NRR QUESTION (1)

Confirm tnat the setpoints in Table 2.2-1 and Table 3.3-3 of the CPSES Technical Specifications are not within 1 5% end of scale.

TV ELECTRIC RESPONSE (1)

As summarized in the attached CPSES Technical Specification Tables 2.2-1 and 3.3-1 (Attachment 2), all but one of the setpoints are within the range of 5% - 95% span of the associated channels. The exception is item 18.b.2 in Table 2.2-1, lurbine Inlet Pressure, or P-13.

Westinghouse functional requirements specify the range of the turbine inlet pressure channels as the equivalent of 0-120% of turbine load. This forms the basis for the 1000 psig span of the installed instrumentation.

The CPSES Technical Specifications require an P-13 setpoint of "10% Rated Thermal Power (RTP) first stage pressure equivalent." Since the actual pressure at 10% RTP must be determined during testing, the currently installed value is an estimate determined through the use of predicted Heat Flow Diagrams supplied by the turbine vendor. This forms the basis for the current setpoint of 42.3 psig.

This setpoint value corresponds to 4.23% of the 1000 psig as built span.

Although this is outside the desired 5% - 95% (span) range for setpoints, it is considered acceptable for the following reasons:

o P-13 was originally intended as a backup to the NIS P-10 signal. More recent experience indicates P-10 is more accurate than originally assumed.

o Testing may result in a setpoint that is within 5% - 95% span.

o With current heat flow predictions and channel range requirements, a P-13 setpoint greater than 5% span cannot be realized without installing a separate channel. The CPSES design is consistent with other Westinghouse plants.

NRR QUESTION (2)

Describe the CPSES methodology for block testing of slave relays. Based on the description in the FSAR, it is unclear whether or not TV Electric can determine that the relays have changed states. Confirm that TV Electric performs complete testing of the slave relays (i.e., testing of the final l actuation device) and not pulse testing.

i b

Attachment 1 to TXX-89233

. . . .Nay 15, 1989 Page 2 of 4 TVFLECTRICRESPONSE(21 Section 7.3.2.2.5 of the FSAR describes the testing methodology for " block i tested" slave relays. This section states that " Operation of these slave l relays, including contact operations, and continuity of the electrical circuits associated with the final device controls are checked in lieu of actual operation." " Actual operation" in this context refers to operation of the final devices. Each " block tested" slave relay is actually energized and allowed to change state. Proper operation of its contacts is verified by means of continuity testing. This block testing methodology also allows for a continuity check to be performed through the final device itself.

Pulse testing is not performed during block testing of Solid State Protection System (SSPS) slave relays.

NRR QUESTION (3)

Confirm that the qualification test errors were considered in the f environmental allowantes of the CPSES Draft Setpoint Study.

TV ELECTRIC RESPONSE (3)

The qualification test errors were considered in the applicable environmental allowances for conditions during which the instruments are expected to operate.

NRR QUESTION (4)

For Steam Generator Water Level (Narrow Range) provide a picture of the Steam generator denoting the :

(a) location and elevation of the narrow range taps; (b) instrument zero; (c) distance between the tube sheet and instrument zero; and (d) distance between the top of the tube bundle and instrument zero.

TV ELECTRIC RESPONSE (4)

See Figure 1 in Attachment 2.

NRRQUESTION(5]

Confirm that the instrument setpoints in Table 2.2-1 and Table 3.3-3 are consistent with those used in the accident analysis where applicable.

Attachment lito TXX-89233

... ;May 15, 1989 Page 3 of 4 1U ELECTRIC RESPONSE (5)

, During the'CPSES Technical.. Specification validation effort, the instrument.

setpoints specified in Table 2.2-1 and Table 3.3-3 were confirmed to be consistent with the setpoints used in the applicable accident analysis.

I NRR QUESTION'(C)- '

k The CPSES methodology for the 1984 Setpoint Study was the same as V. C. Summer. NRR previously reviewed and accepted this methodology.

However,.the current CPSES Draft Setpoint Study includes' Measure and Test Equipment'(M&TE) uncertainties which were not part of the 1984 Setpoint Study, and therefore have not been reviewed or accepted by NRR. Confirm that the inclusion of M&TE uncertainties does not invalidate previous NRR acceptance of the 1984 Setpoint Study.

TV ELECTRIC RESPONSE (6)

The inclusion of M&TE uncertainties into the current Setpoint Study does not invalidate previous NRR acceptance of the 1984 Setpoint Study. It should be noted that inclusion of M&TE uncertainties is consistent with ISA Standard 567.04, 1987, "Setpoints for Nuclear Safety-Related Instrumentation used in Nuclear Power Plants." Furthermore, inclusion of the M&TE uncertainties produces a more conservative setpoint than not incorporating these uncertainties.

NRR QUESTION (7)

The matrices for Steam Generator Level (Narrow Range) identify the setpoint at 49% in the 1984.Setpoint Study and 31% in the current CPSES Draft Setpoint Study. Explain why there is a significant difference between the two setpoints.

TV ELECTRIC RESPONSE (7)

The Steam Generator Water Level - Low-Low trip setpoint is based on the setpoints used in the analyses of the postulated Loss of Normal Feedwater and Main Feedline Break Events. Uncertainties are added onto the accident analysis setpoint to determine the nominal instrument setpoint reported in the Technical Specifications. For the loss of Normal Feedwater event, the accident analysis setpoint was 34.6% of the narrow range span; with uncertainties added, the nominal trip setpoint was determined to be 43.4% of span. For the Main Feedline Break Event, the accident analysis setpoint was 15% of span; with uncertainties added, including additional penalties for postulated adverse containment conditions, the nominal setpoint was calculated

.to be less than 43.4% of span. Therefore, the nominal setpoint reported in the 1984 Setpoint Study was 43.4% of the narrow range span.

i Attachment 1 to TXX-89233 i

, . May 15, 1989 Page 4 of 4 i f More recently, in response to a TV Electric trip reduction initiative, the loss of Normal Feedwater, Loss of AC, and Main Feedline Break events were reanalyzed with trip setpoints of 0% of the narrow range span. When l uncertainties, including the additional penalties attributable to postulated l adverse containment conditions where required, were added to the accident analysis setpoint, the nominal trip setpoint was calculated to be 28% of span.

This value is reported in the final version of the Draft Setpoint Study, issued as WCAP-12123, Revision 2. Note that due to the inclusion of the uncertainties associated with the Measuring and Test Equipment and other plant i' modifications, the total uncertainty for the Main Feedline Break event increased from approximately 18% in the 1984 Setpoint Study to 26.9% in the current Setpoint Study.

NRR QUESTION (8)

Provide a risk analysis for each Accident Monitoring variable in the Standard Technical Specifications, which CPSES considers "not required" for the CPSES Technical Specifications, to demonstrate the risk significance to accident management. Hydrogan concentration is not included.

TV ELECTRIC RESPONSE (8)

Resolution of this issue will be addressed in the CPSES Technical Specification Certification pertaining to Accident Monitoring, which is scheduled to be submitted by May 15, 1989.

AtNachment2toTXX-89233 May 15'p 1989

.Pa0e*1 OT 4

,' - REACTOR TRIP SYSTEM SETFOINT

SUMMARY

TABLE 2.2-1 k'

-TECH SPEC SPAN SETPOINT' SETPOINT .iS % SPAN t

2. POWER RAN6E FLUX {

a. HIGH SETPT 0-120% 109% 90.8%. -

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b. LOW SETPOINT' ' 0-120%

25% 20.8%

3. POWER RANGE FLUX, HIGH POS RATE

, N / A - RATE CIRCUIT 4 POWER RANGE FLUX, HIGH NES. RATE ,.

N'/ A - RATE CIRCUIT

5. -11 -3 INTERMED., RN6 FLUX '

10

.4-10 amp 10 amp 87.5% (1 )

6. SOURCE RN6 FLUX 0 s .,.

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10 -

10 6 ep, gg cas ,. 83.3% (1 ) -

7. OT N-16 6-150% 107.8% ,. 71.9% (2 )

8. OP N-16 0-150% 112% 74.7%

9. PZR PRESS. - LOW 1700-2500 psig 1880 psig 22.5% .

10. PZR PRESS. - HIGH 1700-2500 psig 2385 psig 85.6%

11. PZR LEVEL - HIGH 0-100% 92% 92.0%

12. RCS FLOW - LOW 0-120% 90%'

56.3% (3)

13. S/6 LEVEL - LOW 0-100% 28% 28.0%

14. UV ."'s 42ma-6000 v 4830 v 35.0%

15. UF - RCPs 55-59.5 Hz 57.2 Hz 48.9%

16. TUR8INE TRIP

a. LOW TRIP PRESS 0-200 psig 59 psig 29.5% '

b. TUR8 STOP VLV CLSD N / A - VALVE LIMIT SWITCH #

18. RX TRIP SYS INTLXS

a. IR FLUX - P-6 .n 3

.to

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10 - 10 ano Ix 10 amp 12 5% (1 )

L. 1 ) P-10 (NIS ) 0-120% '

10% 8.3%

2 ) P-13 (TURBINE INLET PRESS) 0-1000 Asic 4' ' psic 4.2% (4 )

c. P-8 (NIS ) 0-120% 40. 40.0%

d. P-10 (NIS ) SEE 18.b.I ABOVE w_ _ .___l----- -

Lii f Atta*c ment '2--to TXX-89233 i*; hay;I,-19,89:

A .Page*2'of 4

.t'.;

,, . (I) LO6-SCALE I

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- (2) ' NOMINAL.SETPOINT. ACTUAL SETP0'INTVARIES WITH PLANT PARAM (3) IN PERCENT D/P

- (4) PREDICTED VALUE ONLY.

. TESTING.. ACTUAL SETPOINT TO BE DETERMINED DIRING STARTUP

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lAttathment 2 to TXX-89233 Ti May.16,19.89 4Page 3 bT 4.

ENGINEERED SAFETY FEATURES ACTUATION SYSTEM SETPOINT

SUMMARY

TABLE S.3-3 TECH SPEC SETPOINT l SPAN SETPOINT

~

AS % SPAN

1. SAFEETY INJECTION

c. CONT PRESS - HI-1 -5 to +60 psig 3.2 psig 12.6% l

d. PZR PRESS - LOW 1700-2500 psig 1820 psig 15.0%

e. STM PRESS LOW 0-1300 psig 605 psig 46.5%

2.c. CONT PRESS - HI-3 -5 to +60 psig 18.2 psig 35.7%

3.b.2 CONT PRESS - HI-3 SEE 2.c ABOVE 4 STEAM LINE ISOLATION

c. CONT PRESS - HI-2 -5 to +60 psic 5.2 psig 17.2%

d. STM PRESS LOW SEE 1.e ABOVE

e. STM PRESS- NE6 RATE N / A - RATE CIRCI"T 5.b. S/6 LEVEL - HI-HI 0-100% 82.4% 82.4%

6.b. S/6 LEVEL - LO-LO 0-100% 28.0% 28.0%

7.b. RWST LO-LO w/ SI 0-1001 40.0% 40.0%

8. LOSS OF POWER

a. 6.9 kV PREF UV 3600-6600 V 5004 V 46.8%

b. 6.9 kV ALT UV 3600-6600 V 5004 V 46.8%

c. 6.9 kV BUS UV 1800-3300 V 2100 V 20.0%

d. 6.9 kV OE6RADEO 3600-6600 V 6054 V 81.8%

e. 480 V OEORADED 280-480 V 439 V 79.5%

f. 480 V LOW 6RIO 280-480 V 447 V B3.5%

10.a PZR PRESS - P-11 1700-2500 psig 1960 psic 3E.5%

-=e mm .

.St.tdchment 2 to TXX-89233

May 15, 1989 -

r Page.4 crf 4-FIGURE I 1

NARROW RANGE -

UPPER TAP A ,

TOP OF TUBE BUNDLE N' ARROW RANGE - N=233.0" LOWER TAP (NOTE 1)

$ n Z:3.33 "

t y ^

l n

Y=336.38 "

X=333.0S"

]

V U TOP OF TUBE SHEET l

X= DISTANCE FROM TOP OF TUBE SHEET TO NARROW RANGE - LOWER TAP (NOTE 1).

Y= DISTANCE FROM TOP OF TUBE SHEET TO TOP OF TUBE BUNDLE. ,.

Z= DISTANCE FROM NARROW RANGE - LOWER TAP TO TOP OF TUBE BUNDLE (NOTE 1).

N= DISTANCE FROM NARROW RANGE - LOWER TAP TO NARROW RANGE - UPPER TAP.

NOTES:

1. INSTRUMENT ZERO = NARROW RANGE - LOWER TAP.

"2. FIGURE IS NOT DRAWN TO SCALE. 1

3. FIGURE INDICATES NDMINAL VALUES AND 15 TYPICAL i FOR ALL NARROW RANGE CHANNELS.

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