ML17298B539

Summary Rept on Design Basis of Shutdown Cooling Sys Relief Valves for Cessar Sys 80.

ML17298B539
Person / Time
Site:	Palo Verde, 05000000, 05000470
Issue date:	11/30/1984
From:	ABB COMBUSTION ENGINEERING NUCLEAR FUEL (FORMERLY
To:
Shared Package
ML17298B538	List: ML17298B537 ML17298B539 ML17298B540
References
NUDOCS 8411280301
Download: ML17298B539 (15)

Text

SUMMARY

REPORT ON THE DESIGN BASIS OF THE SHUTDOWN COOLING SYSTEM RELIEF VALVES FOR CESSAR SYSTEM 80 November 1984 Nuclear Power Systems COMBUSTION ENGINEERING, INC.

Windsor, Connecticut 84i'f28030i 8gii2g;

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TABLE OF CONTENTS Section ~Pa e 1.0 PURPOSE 2.0 SCOPE 3.0 DESIGN BASIS 4.0

5.0 REFERENCES

FIGURES

1.0 PURPOSE The purpose of this report is to describe the design basis that is applied to the relief valves intended for use in the suction piping of the Shutdown Cooling System of C-E System 80 Units. The report will detail the sizing criteria and test specifications applied to these valves.

This report documents a C-E presentation which was delivered to the NRC Staff on November 9, 1984. The purpose of that meeting was to substantiate the operability of these valves.

NOTE: The figures used in this report represent slides which were'sed at that meeting.

2.0 SCOPE This report is applicable to all C-E System 80 units. All the information contained in this report is directly referenceable to CESSAR. In keeping with the CESSAR format no valve manufacturer specific information is presented. CESSAR specifies the necessary valve criteria to meet the system's requirement which. can be supplied by any manufacturer of pressure relief devices.

3.0 DESIGN BASIS The following sections and figures describe the design basis, test specifications, and sizing criteria applied to the relief valves installed in the suction piping of the shutdown cooling system. As identified in CESSAR these are valves SI-179 and SI-189. They are shown on the system piping and instrumentation diagram in CESSAR Fi gure 6.3.2-1B.

3.1 FUNCTION CESSAR identifies these valves as providing a dual function. Their initial function was to protect the shutdown cooling system from overpressurizati on from any possi bl e occurance. Their function was later expanded to provide low temperature overpressure protection (LTOP) for the RCS. For both functions the valves are designed to be redundant, in that one single valve is capable of handling any overpressurization event.

Figure 1 is a schematic of the SCS suction piping showing only the section in the region of the relief valves and the suction line isolation valves which isolate the low pressure SCS from RCS pressure. Also indicated are the safety grade interlocks and alarms associated with the isolation valves. The interlocks provide additional overpressure protection for the system. The alarms connected to the isolation valves annunciate overpressure transients which could challange the relief valves and annunciate that LTOP is inhibited by a closed isolation valve. Only train A of the two redundant suction lines is shown. The nomenclature in parentheses indicates Train B's identification.

3.2 REGULATORY REQUIREMENTS Figure 2 presents the regulatory requirements which create the design bases for the SCS relief valves. Branch Technical Position, RSB 5-1 stipulates the basis for overpressure protection of the SCS and makes direct reference to the ASME Boiler and Pressure Vessel Code for relief capacity sizing. Branch Technical Position, RSB 5-2 creates the basis for the LTOP function of these valves.

3.3 SIZING CRITERIA Figure 3 details the sizing criteria for these valve. This figure also highlights the history of the design of these valves in that they were initially designed for the SCS overpressure protection function.

The L'TOP function was later added to these valves, (which necessitated evaluating LTOP events against the existing design). CESSAR sections 5.4.7.2.2 (4.a2) and 5.2.2. 10.2. 1 explain in detail the data used to determining the capacity and setpoint for these valves. A significant point about the capacity of these valves is that although the initial sizing criteria for the SCS function of these valves appears conservative the inclusion of 'the LTOP events to the valve requirements utilizes the full rated capacity.

3~4 TEST REQUIREMENTS Figure 4 details the test requirements imposed on the valves at their purchase. The ASME code accepts capacity certification by calculation rather than full size testing. C-E imposes additional requirements.

The seismic tests are necessary because these valves are rated for Seismic Class I operation. Prorated tests are acceptable for seismic operability testing. The standard production tests do not require full flow verfication only verification of setpoint and leakage.

I CESSAR Technical Specification 4.4.8.3.2 requires that these valves be tested for setpoint drift once every 18 months.

4.0

SUMMARY

The shutdown cooling relief valves are designed to provide overpressure protection of the low pressure Shutdown Cooling System and LTOP protection of the Reactor Coolant System. They are specified to meet the applicable NRC and industry requirements. The Each valve valves'apacity and setpoint are chosen so as to be redundant.

can individually provide system protection from any design basis overpressurization event.

5.0 REFERENCES

(A) Combustion Engineering Standard Safety Analysis Report (CESSAR),

System 80, Nuclear Steam Supply System, FSAR.

(8) American Society of Mechanical Enginers, Boiler and Pressure Vessel Code, Section III Division 1, Subsection NC, "Class 2 Components."

(C) Nuclear Regulatory Commission, Branch Technical Position:

(C. 1) 'RSB 5-1, "Design Requirements of the Residual Heat Removal System."

(C.2) RSB 5-2, "Overpressurization Protection of Pressurized Water Reactors While Operating at Low Temperatures."

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FIGURE 1 SYSTEM CONFIGURATION SHUTDOWN COOLING SYSTEM SUCTION LINE RELIEF AND I SOLAT ION VALVES CONTA INMENT BUILDING TRAIll A B)

OUT IN S I-179(S I -109)

CONTAI>l1ENT SUMP RCS LPSI M HOT I I PUl1P l(2 LEG SUCTION i SI-655 SI-653 SI-651 LOOP 1 (2)

( (SI-656) (SI-654) (S0-652)

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I I I I I I

I P-103 (104) P-105 (106) P-103 (104)

AUTO CLOSURE SETPOINT: 500 PSIA SETPOINT: 700 PSIA SETPOINT: 700 PSIA OPEN PERMISSIVE SETPOINT: 400 PSIA SETPOINT; 400 PSIA SETPOINT; 400 PSIA LTOP ALARMS: LTOP ALARMS; RCS PRESS > 400 PSIA RCS PRESS > 400 PSIA, VALVE NOT CLOSED VALVE NOT CLOSED RCS TEMP < 260 F RCS TEMP C, 260 F VALVE CLOSED VALVE CLOSED SOURCE: CESSAR FIGURE 6.3.2-1B CESSAR TABLE 7.6-1

FIGURE 2 DESIGN BASIS DESIGN REQUIREMENTS OF RESIDUAL HEAT RENOVAL SYSTEN:

BRANCH TECHNICAL POSITION, RSB 5-1 (ASNE BRPVC SEC III, NC-7000)

OVERPRESSURE PROTECTION OF PNR HHILE OPERATING AT LOM TENPERATURE:

BRANCH TECHNICAL POSITION, RSB 5-2 6

FIGURE 3 SIZING CRITERIA ORIGINAL FUNCTION: SDC OVERPRESSURE PROTECTION CESSAR SECT'ION 5,<f,7,2,2, (P.A2)

~ EACH VALVE; RELIEF OF CO INC IDENT OCCURENCE OF:

2 HPSI PUP[PS (RUNOUT) 3 CHARGING PUNPS ENERGIZATION OF PRESSU'RIZER HEATERS ADDITIONAL FUNCTION: LTOP CESSAR SECTION 5,2,2,10,2,1

~ EVALUATED MITH AS PURCHASED EQUIPMENT

~ LIMITING EVALUATIONS:

.'lASS ADDITION: INADVERTANT SAFETY INJECTION ACTUATION ENERGY ADDITION: RCP START WITH POSITIVE S.G.

TO RCS AT,

FIGURE 4.

Y 8 R FVV PURCHASED TO 1974 ASNE SECTION II I p SUBSECTION NC o ASNE CODE REQUIRB1ENTS CAPACITY CERTIFICATION BY CALCULATIONS OR FLOW TEST FULL SCALE TESTING WAS NOT REQU I RED HYDROSTATIC TESTS o C-E SPECIFICATION REQUIREMENTS SEISMIC OPERABILITY TO BE DEMONSTRATED BY TEST AND/OR ANALYSIS

~ LOADS TO BE CONSIDERED IN THE VALVE DESIGN SEISMIC LOADS SYSTEM PRESSURE I OADS DUE TO VALVE OPERATION

~ STANDARD PRODUCTION TESTS VERIFY SET PRESSURE SEAT LEAKAGE TEST AT 90Ã OF SET PRESSURE