ML20197H554

Proposed Tech Specs,Reflecting Changes in Computational Model & Make RCIC Steam Line flow-high Actuation Instrumentation Valves Consistent w/as-built Plant

ML20197H554
Person / Time
Site:	Grand Gulf
Issue date:	05/12/1986
From:	MISSISSIPPI POWER & LIGHT CO.
To:
Shared Package
ML20197H538	List: AECM-86-0131, Application for Amend to License NPF-29,revising Tech Specs to Reflect Change in Computational Model & Make RCIC Steam Line flow-high Actuation Instrumentation Valves Consistent w/as-built Plant.Fee Paid ML20197H554
References
TAC-61518, NUDOCS 8605190189
Download: ML20197H554 (1)

Text

,

TABLE 3.3.2-2 (Continued)

ISOLATION ACTUATION INSTRUMENTATION SETPOINTS So ALLOWABLE

• • E TRIP FUNCTION TRIP SETPOINT l8?E 3$ 4.

REACTOR WATER CLEANUP SYSIEH ISOLATION (Continued)

VALUE e f. Main Steam Line Tunnel Ambient

{g" o

o g.

Temperature - High 1 185 F** 1 191 F**

Main Steam Line Tunnel A Temp.'- High 5 101 F** 1 104 F**

g h. SLCS Initiation NA NA

i. Manual Initiation NA NA

5. REACTOR CORE ISOLATION COOLING SYSTEM ISOLATION

a. RCIC Steam Line Flow - High g" g,q '/

w 1. Pressure < -363" H 2O 1 2. Time Delay < 3712 HO 2 512 seconds 512 seconds T b. RCIC Steam Supply Pressure - Low > 60 psig

• > 53 psig

c. RCIC Turbine Exhaust Diaphragm Pressure - High 1 10 psig 5 20 psig

d. RCIC Equipment Room Ambient Temperature - High 5 185 F** 1 191 F**

e. RCIC Equipment Room A Temp. - High 1 125*F** < 128 F**

't. f. Main Steam Line Tunnel Ambient g Temperature - High 1 185 F** 1 191 F**

g g. Main Steam Line Tunnel A Temp. - High 5 101 F**

1 104 F**

en h. Main Steam Line Tunnel Temperature Timer g -< 30 minutes _< 30 minutes y i. RHR Equipment Room Ambient Temperature -

High

h. 5 165 Fa* 5 171*F**

.* j. RHR Equipment Room A Temperature -

High 1 99 F** < 102*F**

k. RHR/RCIC Steam Line Flow - High 1 145" H 2O 1 151" H 2O

MISSISSIPPI POWER & LIGHT COMPANY

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EnlMaldiddE Helping Build Mississippi P. O. B O X 164 0, J AC K S O N, MIS SIS SIP PI 39215-1640 May 12, 1986 O. D. KINGSLEY, JR.

VICE PRFSIDENT NUCLE AR OPERATIONS U. S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D. C. 20555 Attention: Mr. Harold R. Denton, Director

SUBJECT:

Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29 File: 0260/0840/L-860.0 Proposed Amendment to the Operating License (PCOL-86/08)

AECM-86/0131 Mississippi Power & Light (MP&L) Company is submitting by this letter a proposed change to the Grand Gulf Technical Specifications to reflect a change in a computational model and make the RCIC Steam Line Flow-High Actuation Instrumentation values consistent with the as-built plant. The inconsistency with as-built conditions has been administratively controlled and was documented by a Materials Non-Conformance Report. A safety evaluation performed in accordance with 10 CFR 50.59 did not identify any unreviewed safety questions, and an evaluation under the guidelines of 10 CFR 21 determined the condition was not reportable.

In accordance with the provisions of 10 CFR 50.30, three (3) signed originals and forty (40) copies of the requested amendment are enclosed. The attachment provides the complete technical justification and discussion to support the requested amendment. This amendment has been reviewed and accepted by the Plant Safety Review Committee (PSRC) and the Safety Review Committee (SRC).

Based on the guidelines presented in 10 CFR 50.92, it is the opinion of MP&L that this proposed amendment involves no significant hazards considerations.

I h f.

cs ua v n a,,l a. n t -- e r, J10AECM35050501 - 1 Member Middle South Utilities System

AECM-86/0131 Page 2 In accordance with the requirements of 10 CFR 170.21, we have determined that the application fee is $150. A remittance of $150 is attached to this letter.

Yours uly, ODK:Im Attachments: GGNS PC0L-86/08

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cc: Mr. T. H. Cloninger (w/a)

Mr. R. B. McGehee (w/a)

Mr. N. S. Reynolds (w/a)

Mr. H. L. Thomas (w/o)

Mr. R. C. Butcher (w/a)

Mr. James M. Taylor, Director (w/a)

Office of Inspection A Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Dr. J. Nelson Grace, Regional Administrator (w/a)

U. S. Nuclear Regulatory Commission Region II 101 Marietta St., N. W., Suite 2900 Atlanta, Georgia 30323 Dr. Alton B. Cobb (w/a)

State Health Officer State Board of Health Box 1700 Jackson, Mississippi 39205 J10AECM86050501 - 2 L

REMITTANCE ADVICE vrN On uuusen C"'C K NO-Cusex oATE 04/16/86 V'*D "

US:NUC REG COMM 929958 04-0127

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c Gaoss AMOUNT DISCOUNT NET AMOUNT

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34 486 10CFR170 APPLICATION FEE 04-2618 I l5q00 3, I i jl5000

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1 i i l l I I 1 1 I I I I I I l l l DEPOSIT GUAR ANTY N ATIONAL BANK 85 543 Jackson, Mississippl 39205 T MIDDLE SOUTH ENERGY, INC.

P.O. BOX 1640 . JACKSON, MISSISSIPPI 39205 CHECK NO.04-0127 JOINT ACCOUNT E CK DaT,E, DOLLAas CENTS 04 16 86 $150iOO PAY U.S. NUCLEAR REGULATORY l TO THE COMMISSION J ccos n O WASHINGTON, DC 20555 /

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cou~" a$'a~t o n' l "005 2419e - :DE 5 30 54 3Es: e 2 3 a' 5 9 5 a' 2 Er i

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BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION LICENSE N0. NPF-29 DOCKET N0. 50-416 IN THE MATTER OF MISSISSIPPI POWER & LIGHT COMPANY and MIDDLE SOUTH ENERGY, INC.

and SOUTH MISSISSIPPI ELECTRIC POWER ASSOCIATION AFFIRMATION I, 0. D. Kingsley, Jr., being duly sworn, stated that I am V':e President, Nuclear Operations of Mississippi Power & Light Company; that on behalf of Mississippi Power & Light Company, Middle South Energy, Inc., and South Mississippi Electric Power Association I am authorized by Mississippi Power & Light Company to sign and file with the Nuclear Regulatory Connission, this application for amendment of the Operating License of the Grand . Gulf Nuclear Station; that I signed this application as Vice President, Nuclear Operations of Mississippi Power & Light Company; and that the statements made and the matters set forth therein are true and correct to t best of my knowledge, information and belief.

n 1- n/

0. y/ Kin s1 .

STATE OF MISSISSIPPI COUNTY OF HINDS SUBSCRIBED AND SWORN T0 before me, a Notary Public, in and for the County and State above named, this /PMday of Mag , 1986.

(SEAL) l Nyry~Public My commission exp'res:

W 2 7,. 19T 7 J10AECM86050501 - 4

1) NPE-85/05

SUBJECT:

Technical Specification Table 3.3.2-2, page 3/4 3-18 DISCUSSION: It is proposed to change the subject technical specification table item 5.a., RCIC Steam Line Flow-High, trip setpoint and allowable value from less than or equal to 363" H 2 O and less than or equil to 371" H2 O to less than or equal to 56" H 2 O and less than or equal to 64" H2 0, respectively, This change will make the RCIC Steam Line Flow-High Isolation Actuation Instrumentation values consistent with the as-built plant.

JUSTIFICATION: The generic design for pre-BWR/6 GE reactors included a Reactor Core Isolation Cooling (RCIC) system for mitigation of the water level transient following a main steam line isolation event with a pumping capacity of 500 to 600 gpm at rated

. reactor pressure. To accommodate the RCIC pumping capacity of 500 to 600 gpm at rated reactor pressure, a 4" diameter RCIC turbine steam supply line was required. This design

! was analyzed to be adequate to satisfy the isolation cooling

] requirements for those pre-BWR/6 reactors whose vessel measured -

j an inside diameter of 238" and for the smaller capacity BWR/6's which retained the 238" vessel.

The Grand Gulf Nuclear Station (GGNS) design, however, is a 251" inside diameter vessel, and analysis revealed that an increase in RCIC capacity to approximately 800 gpm was required to provide adequate isolation cooling for the larger vessel. This necessitated an increase in the steam supply piping to 6". The  ;

ensuing analysis to dettermine the high-flow isolation setpoint for this system was performed, however, on a model using the 4" steam supply piping of the previous design. This resulted in a significantly higher steam velocity following a postulated RCIC LOCA than would be experienced with the 6" line, and hence a higher differential pressure across the flow element.

s After MP&L identified the discrepancy, the NSSS vendor (General i Electric) modified the computational model to incorporate the 6" line and calculated the revised analytical limit of 73.3" H2 0. This is the differential pressure corresponding to a flow rate of 300% of rated RCIC steam flow, which was the flowrate assumed in the safety analysis for RCIC LOCA. The revised l allowable value of 64" H O 2 includes allowance for combined instrument accuracy and calibration errors. The revised trip setpoint of 56" H2 O includes allowance for instrument drift.

4 J16ATTC86032701 - 1

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These setpoints have been and continue to be administratively controlled to the proposed values by Technical Specification Position Statement No. 65.

It is appropriate to note that, although this setpoint is an analyzed value and not subject to revision following start-up testing by the generic footnote to the table as many of the other values are, it was the RCIC start-up test that first revealed this discrepancy. Review of the test data revealed that lower than anticipated differential pressures were being recorded and prompted the evaluation that identified this discrepancy.

SIGNIFICANT HAZARDS CONSIDERATION:

The proposed changes reflect a change in the computational model to correctly reflect the as-built plant. Although the current flow rate of 300% of rated RCIC steam flow was used in the safety analysis for a RCIC LOCA, the differential pressure reading corresponding to the 300% of rated flow was originally calculated for a 4" pipe instend of the 6" pipe actually in GGNS.

The technical evaluation of whether or not the change in the RCIC Steam Line Flow-High trip setpoint and allowable value '

involves significant hazards considerations is centered in three standards:

A. First Standard - Involve a significant increase in the probability or consequences of an accident previously evaluated.

The safety analysis for a RCIC LOCA assumes a flow rate of 300% of the rated RCIC steam flow. This proposed change does not impact the values used in or the results obtained from the safety analysis for RCIC LOCA. The revised values on the Technical Specification Table 3.3.2-2 are the correct values for the differential pressure corresponding to a flow rate of 300% of rated RCIC steam flow, for a 6" steam supply pipe. Therefore, changing the RCIC Steam Line Flow-High values in Table 3.3.2-2 does not involve any increase in the probability or consequences of an accident previously evaluated.

B. Second Standard - Create the possibility of a new or different kind of accident from any accident previously evaluated.

i

• j J16ATTC86032701 - 2

Changing Technical Specification Table 3.3.2-2 has no impact on any type of accident, any malfunction of equipment, or the possibility of any accident or equipment malfunction. The proposed change merely tratslates the 300% of rated RCIC steam flow (used in the safety analysis) to the correct differential pressure values for a 6" steam supply pipe for use in the technical specifications. This proposed change, therefore, does not create the possibility of a new or different kind of acciden't from any accident previously evaluated.

C. Third Standard - Involve a significant reduction in a margin of safety.

Changing the RCIC Steam Line Flow-High trip setpoint to the proposed revised values actually increases the margin of safety in the plant. The new values of 5 56" H 2 O and 5 64" H2 O reflect accurate design information for the as-built plant; they are more conservative than the values currently in Technical Specification Table 3.3.2-2.

Revising Table 3.3.2-2 to incorporate the correct values for a 6" steam supply pipe, therefore, does not involve a significant reduction in a margin of safety.

This proposed change to Technical Specification Table 3.3.2-2 involves no significant hazards consideration.

J16ATTC86032701 - 3

hyE TABLE 3.3.2-2 (Continued)

E a ISOLATION ACTUATION INSTRUMENTATION SETPOINTS c)

ALLOWABLE E TRIP FUNCTION TRIP SETPOINT 0m VALUE

4. REACTOR WATER CLEANUP SYSTEM ISOLATION (Continued) i \ "E f. Main Steam Line Tunnel Ambient Temperature - High 5 185 f**

1 191 Fa*

g g. Main Steam Line Tunnel a Temp. - High 5 101*Fa* $ 104 F**

h. SLCS Initiation NA NA Cs i. Manual Initiation NA NA

5. REACTOR CORE ISOLATION COOLING SYSTEM ISOLATION Q

a. RCIC Steam Line Flow - High 54" 4q '/

Q w 1. Pressure < -363" H 2O < 971" H 2O N 1 2. Time Delay 512 seconds 512 seconds N b. RCIC Steam Supply Pressure - Low 1 60 psig 1 53 psig

\1 *Y c. RCIC Turbine Exhaust Diaphragm Pressure - High 5 10 psig 5 20 psig i d. RCIC Equipment Room Ambient Temperature - High 1 185*F** 1 191*F**

e. RCIC Equipment Room a Temp. - High 1 125*F** 1 128*F**

> f. Main Steam Line Tunnel Ambient g Temperature - High 1 185 F** 1 191*F**

1, g. Main Steam Line Tunnel a Temp. - High 1 101*F** 1 104 F**

Or e, h. Main Steam Line Tunnel Temperature Timer t 5 30 minutes 1 30 minutes 3 i. RHR Equipment Room Ambient Temperature -

High 5 165*F**

1 171*F**

.* j. RHR Equipment Room a Temperature -

High 1 99*F** 1 102*F**

k. RHR/RCIC Steam Line Flow - High 5 145" H20 1 151",H 2O

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