ML13331B139
| ML13331B139 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 02/25/1989 |
| From: | Baskin K Southern California Edison Co |
| To: | NRC/IRM |
| References | |
| NUDOCS 8903010167 | |
| Download: ML13331B139 (34) | |
Text
Southem California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 KENNETH P. BASKIN TELEPHONE VICE PRESIDENT 818-302-1401 February 25, 1989 U. S. Nuclear Regulatory Commission Attention:
Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206 Supplement I to Amendment Application No. 159 "ESF Switchover from Injection to Recirculation Mode Modification" San Onofre Nuclear Generating Station Unit 1 By letter dated November 11, 1988, SCE submitted Amendment Application Number 159 to include surveillance of a planned modification to trip the safety injection/feedwater pumps on low-low RWST level.
This modification would install an automatic trip feature in the Safety Injection System to trip the Safety Injection and Feedwater pumps on a low-low RWST level to ensure that sufficient water inventory was available to prevent the potential cavitation of the Charging and Refueling Water pumps during a realignment from safety injection mode to recirculation mode following a LOCA. Additional information regarding the design details of the trip feature was provided to the NRC by letter dated January 13, 1989, which included the result of the setpoint analysis of this automatic trip. Further details of this setpoint analysis were requested by the NRC to support the staff review of the amendment request.
Since those discussions, an additional modification has been identified and is being implemented which would provide additional redundancy to the automatic pump trips.
The MOV 850 A, B, & C valves will be given a signal to automatically close at the same time the pumps are given a trip signal.
Since these valves are in the three primary injection flow paths for safety injection to the RCS, they provide a completely redundant method of automatically terminating SI flow. Therefore, no single failure could result in a failure of automatic termination of SI flow.
The purpose of this letter is to provide the details of the setpoint analysis, provide design information on the redundant automatic MOV 850 A, B, and C valves closure, and submit Supplement 1 to Proposed Change No. 186 to include the actual trip setpoint, surveillance requirements, an action statement and their bases in the Appendix A, Technical Specifications.
8903010167 890225 PDR ADOCK 05000206 P20 PNU
Document Control Desk
-2 If you have any questions or require additional information, please contact me.
Respectfully submitted, By:
Z~Z 4 4A Kenneth P. Baskin Vice President Subscribed and sworn to before me this A
day of OFFICIAL SEAL AGNES CRABTREE Notary Public-California Notar Public in and for the County of LOS ANGELES COUNTY Los Angeles, State of California MyComm.Exp.Sep.14.1990 Enclosure cc: J. B. Martin, Regional Administrator, NRC Region V F. R. Huey, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of SOUTHERN
)
CALIFORNIA EDISON COMPANY
)
and SAN DIEGO GAS & ELECTRIC
)
Docket No. 50-206 COMPANY San Onofre Nuclear
)
Generating Station Unit No. 1
)
CERTIFICATE OF SERVICE I hereby certify that a copy of the Supplement to Amendment Application No. 156 was served on the following by deposit in the United States Mail, postage prepaid, on the 27th day of February 1989.
Benjamin H. Vogler, Esq.
Staff Counsel U.S. Nuclear Regulatory Commission Washington, D.C. 20555 David R. Pigott, Esq.
Samuel B. Casey, Esq.
Orrick, Herrington & Sutcliffe 600 Montgomery Street San Francisco, California 94111 L. G. Hinkleman Bechtel Power Corporation P.O. Box 60860, Terminal Annex Los Angeles, California 90060 Michael L. Mellor, Esq.
Thelen, Marrin, Johnson & Bridges Two Embarcadero Center San Francisco, California 94111 Huey Johnson Secretary for Resources State of California 1416 Ninth Street Sacramento, California 95814 Janice E. Kerr, General Counsel California Public Utilities Commission 5066 State Building San Francisco, California 94102
-2 C. J. Craig Manager U. S. Nuclear Projects I ESSD Westinghouse Electric Corporation Post Office Box 355 Pittsburgh, Pennsylvania 15230 A. I. Gaede 23222 Cheswald Drive Laguna Niguel, California 92677 Frederick E. John, Executive Director California Public Utilities Commission 5050 State Building San Francisco, California 94102 Docketing and Service Section Office of the Secretary U.S. Nuclear Regulatory Commission Washington, D.C. 20555 J am'A. B le t
.s Enclosure DESCRIPTION OF SUPPLEMENTAL CHANGES TO PROPOSED CHANGE NO. 186 TO THE TECHNICAL SPECIFICATIONS PROVISIONAL OPERATING LICENSE NO. DPR-13 Supplement 1 The following is a supplemental request to revise Sections 3.3, "Safety Injection and Containment Spray Systems," and 4.2, "Safety Injection and Containment Spray System" of the Appendix A, Technical Specifications for San Onofre Nuclear Generating Station, Unit 1 (SONGS 1).
Description of Supplemental Change Subsequent to the submittal of Proposed Change No. 186 by letter dated November 11, 1988, an additional modification to implement automatic closure of MOV 850A, 850B, and 850C on low-low refueling water storage tank level in addition to the automatic main feedwater/safety injection pump trip was identified. In addition, at the request of the NRC staff this supplement also provides the actual RWST level setpoint and a discussion of its basis in Technical Specification Section 3.3.1, "Safety Injection and Containment Spray Systems" and specifies the required surveillance in Section 4.2, "Safety Injection and Containment Spray System."
Existing Technical Specifications See Attachment 1.
Proposed Technical Specifications See Attachment 2.
Significant Hazards Consideration Analysis The analysis provided in PCN 186, submitted as Amendment Application No. 159 by letter dated November 11, 1988, bounds the additional changes included in this supplement. The setpoint analysis incorporated the time-dependent single active failures and their impacts on Safety Injection and Main Feedwater pump flow rates, charging and containment spray, operator action times, and other related criteria. This automatic trip is being implemented to ensure adequate time to complete the sequence of emergency core cooling system operation from injection to long-term core cooling (recirculation) while minimizing operator action.
One change in this proposed change is to specify the actual setpoint for the low-low RWST trip. The upper limit of the automatic trip setpoint is determined by the borated water inventory remaining after pumping the minimum volume from the Technical Specification RWST level into the containment sump to support recirculation for long term post-LOCA cooling. The lower limit is the minimum RHST level required to support charging and containment spray pump operations. In addition, water is required for a period of charging and containment spray to allow for manual realignment of the safety injection system consistent with the existing EOI and a conservative allowance for safety injection and main feedwater pump coastdown. Since the total flow rates from the RWST for the injection and transition periods are dependent on
-2 the assumed single active failure, an event-specific single failure response evaluation was performed as a part of the setpoint analysis to define these combinations and the required lower RWST level limit for the automatic trip.
The setpoint analysis considered no failures and the following relevant single failures:
- 1. One diesel generator;
- 2. One 4160 Volt Bus;
- 3. One 480 Volt Bus;
- 4. One 125 Volt DC Bus;
- 6. MOV-1100C in conjunction with the presence or absence of SIS or SISLOP.
The upper limit of the automatic pump trip setpoint is determined from the minimum volume required to be pumped from the RWST into the containment sump to meet recirculation mode NPSH requirements. The minimum volume is approximately 187,000 gallons of the minimum required Technical Specification level of 240,000 gallons. The lower bounding level for the automatic trip consists of a minimum water volume of 20,350 gallons, equivalent to 7% RWST level, to prevent the potential cavitation of charging and refueling water pumps, in addition to the maximum volume required for the 5-minute window to manually complete recirculation realignment, and an allowance of 10 seconds equivalent full flow to bound SI/FW pump coastdown. The maximum and minimum allowable water volumes based on this methodology are approximately 53,000 and, at most, 44,400 gallons, respectively, which correspond to approximately 21% and 17% RWST levels. The proposed setpoint of 20% includes instrument uncertainties of level switches to prevent both premature and delayed terminations of the safety injection/feedwater flow. The automatic trip feature will ensure that sufficient time is available for remaining operator actions.
This is consistent with the NRC recommendation in the San Onofre Unit 1 SEP Topic VI-7.B to install the automatic trip to terminate the SI/FW flow on a low-low RWST level.
In addition to the automatic trip of the main feedwater/safety injection pumps, it has been determined through completion of an event specific single failure analyses that a failure of a 125 VDC bus may prevent manual or automatic stopping of the feedwater and safety injection pumps from the control room. This would necessitate operator action to close the Safety Injection Discharge Header Block Valves (MOV 850A, 850B, and 850C) within 30 seconds following receipt of low-low RNST alarm in order to successfully complete switchover to recirculation mode with sufficient inventory remaining in the RWST. An additional modification being implemented will automatically close the block valves on low-low RNST level.
The specific drawing change notices (DCNs) have not been completed as of the date of this letter, but the resulting control circuits will have the general configuration indicated on the attached sketch.
(Relay status lights, test buttons and annunciator outputs have been omitted for clarity.)
This configuration provides for automatic closure of MOV-850 A, B, and C, following
-3 a SIS/SISLOP, on a 2-out-of-2 coincidence of low-low RNST level actuation signals from Train A and Train B. This 2-out-of-2 coincidence is required to prevent premature valve closure in the event of a single failure causing a spurious signal from one train. The actuation signal to the valves from each train is provided on a 1-out-of-2 coincidence of the low-low RWST level Pump trip signals for the Safety Injection (SI) pump and Feedwater (FW) pump in that train, using de-energize to actuate output relays.
The pump trip signals in each train are generated on a 2-out-of-3 coincidence of low-low RWST level following a SIS/SISLOP. The SIS/SISLOP permissive precludes spurious FW pump trip during normal operation. The signal is sealed in to prevent disarming of the automatic low-low RWST level trip when the sequencers are blocked and reset as part of the post-accident operator actions. Concurrent actuation of two manual switches is required to reset this seal-in. The logic is generated separately for each pump, using separate sets of level switch relay contacts for the pumps in each train. The three level switch relays per train and three valve output relays per train are powered from the 125 VDC SI pump controls. This configuration, and the 1-out-of-2 coincidence within each train ensures that no single active failure, including that of individual breaker control power, 125 VDC bus, switch, relay, fuse or other device can prevent both pump trip and the valve closure signal for that train.
Automatic block valve closure is redundant to the automatic pump trip and assures that no single failure would prevent fulfillment of the primary mode injection flow termination function.
Safety Analysis The proposed changes discussed shall be deemed to involve a significant hazards consideration if there is a positive finding in any one of the following areas:
- 1. Will operation of the facility in accordance with this proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?
RESPONSE: No The proposed changes will eliminate the need for certain operator actions in response to previously evaluated postulated accidents.
These changes will reduce the probability of operator error following certain accidents and thus the initiating frequency of previously evaluated accidents will not be increased because the proposed changes will decrease the core melt frequency associated with accident scenarios in which operator action is required to trip the safety injection/feedwater pumps on low-low RWST level.
Decreased core melt frequency will result in decreased consequences for these accidents.
-4
- 2. Will operation of the facility in accordance with this proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?
RESPONSE: No The proposed changes only affect accident mitigation systems and no postulated failures of the components to be installed by this proposed change could result in a new or different accident.
- 3. Will operation of the facility in accordance with this proposed change involve a significant reduction in a margin of safety?
RESPONSE: No The proposed changes will assure that at the proper RWST water level the main feedwater/safety injection pumps will be tripped and the SI header block valves closed to allow the operators to realign the safety injection system for long term recirculation.
This will serve to maintain the existing margin of safety associated with core cooling following a loss of coolant accident.
Safety and Significance Hazards Consideration Determination Based on the Safety Evaluation provided in Amendment Application No. 159 and the information provided above, it is concluded that: (1) the supplemental changes to Proposed Change No. 186 do not involve a significant hazards considerations defined by 10 CFR 50.92; and (2) there is reasonable assurance that the health and safety of the public will not be endangered by the proposed change.
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SAFETY INJECTION PUMP CONTROLS
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K 3.3 SAFETY INJECTION AND CONTAINMENT SPRAY SYSTEMS 3.3.1 Operating Status Applicability Applies to the operating status of the Safety Injection and Containment Spray Systems.
Objective To define those conditions necessary to ensure availability of the Safety Injection and Containment Spray Systems.
Specification A. The reactor shall not be made or maintained critical unless the following conditions are met. In addition, the reactor coolant system temperature shall not be increased above 2000F unless the containment spray system, the refueling water storage tank and the associated valves and interlocks are operable.
(1)
Safety Injection Systems
- a. Refueling tank water storage and boron concentration 34 comply with Specification 3.3.3.
4/1/77
- b. Two safety injection pumps are operable.
- c. Two feed water pumps are operable.
- d. Two recirculation pumps are operable, except as indicated in item D below.
- e. The recirculation heat exchanger is operable.
- f. Two charging pumps are operable.
- g. Two component cooling water pumps are operable.
- h. Two saltwater cooling pumps are operable.
The reactor may 85 be maintained critical with one saltwater cooling pump 11/26/84 provided the auxiliary saltwater cooling pump or two screen wash pumps are available as backup. Return the inoperable pump to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in Hot Standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in Cold Shutdown within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. The backup pump(s) shall be demonstrated operable by test within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of declaring the saltwater cooling pump inoperable.
- i. A minimum of 5400 pounds of anhydrous trisodium phosphate 44 is stored in the containment sump in racks provided.
10/31/78 3-28 Revised:
12/3/84
(2)
Containment Spray System
- a. Two refueling water pumps are operable.
- b. Two hydrazine additive pumps are operable.
- c. Hydrazine tank level and hydrazine concentration comply with Specification 3.3.4.
(3)
Valves and interlocks associated with each of the above systems are operable.
(4)
Effective leakage from the recirculation loop outside the containment shall be less than 625 cc/hr as calculated from the following formula.
Effective Leakage.= a1 x L 1 + a2 xL + a3 x L3 where, L1 = pump and valve leakage which drains to auxiliary building sump L2 =
valve leakage in auxiliary building or doghouse L3 =
valve leakage outside 34 4/1/77 a1 =
iodine release factor for leakage in auxiliary building sump a2 =
iodine release factor for leakage in auxiliary building or doghouse a3 =
iodine release factor for leakage outside the auxiliary building or doghouse If effective leakage from the recirculating loop outside the containment exceeds 625 cc/hr, make necessary repairs to limit leakage to 625 cc/hr 44 within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in cold shutdown within the next 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
10/31/78 Typo-revision:
1/15/80 3-29 Revised:
1/04/79
B. During critical operation or when the reactor coolant system temperature is above 200oF, as appropriate per Item A above, maintenance shall be allowed on any one of the following items at any one time:
(1) One motor-operated valve at a time (MOV 1100B or 1100D) in the recirculation loop upstream of the charging pump suction header for a period of time not longer than 72 consecutive hours.
(2) One refueling water pump and/or its associated discharge valve at a time, for a period not longer than 72 consecutive hours.
(3) One hydrazine pump and/or its associated discharge valve (SV600 or 601) at a time, for a period of time not longer than 72 consecutive hours.
(4) One charging pump for a period of time not longer than 72 consecutive hours.
34 1/4/77 (5) One of the two required component cooling water pumps for a period of time not longer than 72 consecutive hours.
(6) One of the two saltwater cooling pumps with the auxiliary saltwater cooling pump or screen wash pumps 85 available as backup for a period of time not longer 11/26/84 than 72 consecutive hours. The backup pump(s) shall be demonstrated operable by test within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of declaring the saltwater pump inoperable.
C. Prior to initiating maintenance on any of the components, the duplicate (redundant) component shall be tested to demonstrate availability.
D. In the event of a failure of a recirculating pump, plant operation may continue provided operability of the remaining pump and its associated motive and control power are satisfactorily demonstrated on a daily basis, including verification that the containment spray bypass valves (CV517 and 518) are closed.
Basis:
The requirements of Specification A assure that before the reactor can be made critical, or before the reactor coolant system heatup is initiated, adequate engineered safeguards are operable. The limit of 625 cc/hr for the recirculation loop leakage ensures that the combined 0-2 hr. EAB thyroid dose due to recirculating loop leakage and containment leakage will not exceed the limits of 10 CFR 100.
The formula for determining the leakage incorporates consideration of the significance of leakage in different plant areas. The iodine release factor adjusts actual pump or valve leakage to account for the fraction of the iodine in the leakage which would actually be released to the atmosphere. The iodine release factors in the auxiliary building sump, the auxiliary building or doghouse, and outside are 0.05, 0.5, and 1.0, respectively.
Typo-Revised:
11/28/84
When the reactor is critical or the reactor coolant system temperature is above 200 0F, maintenance is allowed per Specifications B and C providing requirements in Specification C are met which assure operability of the redundant component. The specified maintenance times are a maximum, and maintenance work will proceed with diligence to return the equipment to an operable condition as promptly as possible.
Operability of the specified components shall be based on the results of Surveillance Standard No. 4.2.
34 4/1/77 The allowable maintenance periods are based upon the repair of certain specific items.
Based on the demonstration that equipment redundant to that removed from service is operable, it is reasonable to maintain the reactor at power over this short period of time.
In the unlikely event that the need for safety injection should occur:
--functioning of one train will protect the core.
(1)(2)(3)(4) Containment sprays alone, however, will maintain containment pressure under design pressure. (5)
--functioning of one of the two hydrazine additive pumps and associated discharge valve will effect introduction of hydrazine into containment spray water. This provides for absorption of airborne fission products and reduction of the thyroid doses associated with the maximum hypothetical accident to within 10 CFR 100 limits.
--dissolution of 5400 pounds of anhydrous trisodium phosphate stored in the sump will ensure that the pH of the water in the sump will be greater than 7 within four (4) hours, so as to 44 prevent chloride stress corrosion cracking of systems and 10/31/78 components exposed to the circulating sump water.
In the event of inoperability of a recirculation pump, plant operation may continue since either pump is sufficient and a daily operability demonstration of the remaining pump and its associated motive and control power provides assurance that it will be operable if required.
References:
(1) Final Engineering Report and Safety Analysis, Paragraph 10.1.
(2) Final Engineering Report and Safety Analysis, 34 Paragraph 5.1.
4/1/77 3-31 Revised:
1/4/79
0 0
(3) "San Onofre Nuclear Generating Station," report forwarded by letter dated December 29, 1971, from Jack B. Moore to Director, Division of Reactor Licensing, USAEC, subject:
Emergency Core Cooling System Performance, San Onofre Nuclear Generating Station, Unit 1.
34 (4) USAEC Safety Evaluation of ECCS Performance Analysis for 4/1/77 San Onofre Unit 1, forwarded by letter dated March 6, 1974, from Mr. Donald J. Skovholt to Mr. Jack B. Moore.
(5) Supplement No. 1 to the Final Engineering Report and Safety Analysis, Section 5, Question 3c.
3-32 Revised:
1/4/79
4.2' SAFETY INJECTION AND CONTAINMENT SPRAY SYSTEM 62 4/20/81 4.2.1 SAFETY INJECTION AND CONTAINMENT SPRAY SYSTEM PERIODIC TESTING APPLICABILITY:
Applies to testing of the Safety Injection System and the Containment Spray System.
OBJECTIVE:
To verify that the Safety Injection System and the 34 Containment Spray System will respond promptly and properly 4/1/77 if required.
SPECIFICATION:
I. System Tests A. Hot Safety Injection System Test (1) When the plant is planned to be shutdown from MODE 1 operation and is planned to enter MODE 5 operation, a Hot SIS Test shall be performed in MODE 3 while RCS pressure is above 1500 psi but not more often than once every 9 months. The test shall include a determination of the force required to open valves NV 851 A and 8 and the margin of available actuation force.
114 (2) The test will be considered satisfactory if:
11/18/88 (a) control board indication and visual observations indicate all components have operated and sequenced properly. That is, the appropriate pumps have started and/or stopped and started, and all valves have completed their travel.
(b) the measured actuator force for both the HV-851 A and B valves is equal to or less than 10,000 lbf.*
(3) If the measured actuator force of either HV-851 A or B is between 10,000 and 22,000 Tb, the HV-851 A and B valves shall be considered OPERABLE but the future testing interval shall be accelerated as determined by the following equation:
- Upon receipt of satisfactory data from continuing testing and analysis, the NRC staff will consider a request from Southern California Edison Company to change this number to more accurately reflect existing conditions.
SAN ONOFRE -
UNIT 1 4-36 Revised:
12/9/88
T =TL (22,000 - F) 12,000 where:
T = maximum time in days of operation allowed before next surveillance test is required T L = time in days of operation since the last surveillance test F = measured actuator force 114 (4) If the measured actuator force of either HV-851 A or 11/18/88 8 is greater than 22,000 lbf, test-results shall be reported to the NRC pursuant to Specification 6.9.2 along with proposed corrective actions. NRC approval shall be obtained prior to returning the unit to service.
- 8. Trisodium Phosphate Test (1) A test of the trisodium phosphate additive shall be conducted once every refueling to demonstrate the availability of the system. The test shall be performed in accordance with the following procedure:
(a) The three (3) storage racks are visually observed to have maintained their integrity.
(b) The three (3) racks, each with a storage capacity of 1800 pounds of anhydrous trisodium phosphate additive, are visually observed to be full.
(c) Trisodium phosphate from one of the sample storage racks inside containment shall be 44 submerged without agitation, in 25+0.5 gallons 10/31/78 of 1500F to 175*F distilled water borated to 3900+100 ppm boron.
(2) The test shall be considered satisfactory if the 114 racks have maintained their integrity, the racks are ill/18/88 visually observed to be full, and the trisodium phosphate dissolves to the extent that a minimum pH of 7.0 is reached within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of the start of the test.
SAN ONOFRE -
UNIT 1 4-37 Revised:
12/9/88
C. Containment Spray System Test 114 m11/18/88 (1) During reactor shutdown at intervals not longer than the normal plant refueling intervals, a "no-flow" system test shall be conducted to demonstrate proper 44 availability of the system. The test shall be 10/31/78 performed either by closing a manual valve in the system or electrically disabling the refueling water pumps and initiating the system by tripping the normal actuation instrumentation.
(2) The test will be considered satisfactory if visual 114 observations indicate all components have operated 11/18/88 satisfactorily.
(3) At least once every second refueling outage an air 114 flow test shall be performed to demonstrate the 11/18/88 absence of blockage at each containment spray nozzle.
II. Component Tests A. Pump Tests (1) In addition to the above test, the safety injection, 114 recirculation, spray additive and refueling water 11/18/88 pumps shall be started at intervals not to exceed one month to verify that they are in satisfactory running order.
(2) Acceptable levels of performance shall be as follows:
(1) The safety injection pumps shall reach and be capable of maintaining 95% of their rated shutoff head within 10 seconds after starting.
(2) The refueling water pumps shall be capable of 34 maintaining 90% of their rated shutoff head.
4/1/77 (3) The recirculation pumps shall be run dry.
Proper starting of the pump is confirmed by observation of the running current on the ammeter.
(4) The spray additive pumps shall be capable of maintaining their rated flow at a discharge pressure not less than 90% of their rated discharge pressure.
SAN ONOFRE -
UNIT 1 4-38 Revised:
12/9/88
0 B. Leakage Testing 114 11/18/88 (1) The recirculation loop outside containment (including the Containment Spray System) shall be pressurized at a pressure equal to or greater than the operating pressure under accident conditions at intervals not to exceed the normal plant refueling interval.
Visual inspections for leakage shall be made and if leakage can be detected, measurements of such leakage shall be made. In addition, pumps and valves of the recirculation loop outside containment which are used during normal operation, shall be visually inspected for leakage at intervals not to exceed once every six months. If leakage can be detected, measurements of such leakage shall be made.
114 (2) The non-redundant Containment Spray System piping 111/18/88 shall be visually inspected at intervals not to exceed the normal plant refueling interval.
Observations made as part of compliance with 44 Paragraph C, above, or Paragraph I.C(2) of Technical 10/31/78 Specification 4.2 will be acceptable as visual inspection of portions of non-redundant Containment Spray System piping.
BASIS:
The Safety Injection System is a principal plant safeguard.
It provides means to insert negative reactivity and limits core damage in the event of a loss of coolant or steam break accident. (1)(2)(3)
Preoperational performance tests of the components are performed in the manufacturer's shop. An initial system flow test demonstrates proper dynamic functioning of the system.
Thereafter, periodic tests demonstrate that all components are functioning properly.
For these tests, flow through the system is generally not required. However, in the case of the "Hot SIS Test," actual conditions of an SI event are simulated. This test is performed to assure that long-term set of the valve seat faces on HV-851 A and 8 has not caused the valves to become inoperable. The test is required to be performed as the plant is shutting down from MODE 1 in order 114 to assure that the valves have not been disturbed (1.e., the 1/18/88 long-term set is still in effect) and that full dynamic conditions that would occur during an actual SI event are simulated. When possible the test should be performed prior to stopping the feedwater pumps (this is not a requirement).
This will further assure that the valves will be in the same condition as when required for an actual Safety Injection event since the discharge pressure of the feedwater pumps acting on the valves will keep them seated even considering any backpressure built up in the downstream St header. The SAN ONOFRE -
UNIT 1 4-39 Revised:
12/9/88
equation used to determine future intervals if actuator force is between 10,000 lbf and 22,000 lbf is developed by shortening the interval in direct proportion to the degree to which the force exceeds 10,000 lbf.
During the test, all 114 components are verified to have operated and sequenced 11/18/88 properly.
The tests required in this specification will demonstrate that all components which do not normally and routinely operate will operate properly and in sequence if required.
The portion of the Recirculation system outside the containment sphere is effectively an extension of the boundary of the containment. The measurement of the recirculation loop leakage ensures that the calculated EAB 0-2 hr. thyroid dose does not exceed 10 CFR.100 limits.
The trisodium phosphate stored in storage racks located in the containment is provided to minimize the possibility of stress corrosion cracking of metal components during operation of the ECCS following a LOCA. The trisodium phosphate provides this protection by dissolving in the sump water and causing its final pH to be raised to 7.0 - 7.5.
44 The requirement to dissolve trisodium phosphate from one of 10/31/78 the sample storage racks in distilled water heated and borated, to the extent recirculating post LOCA sump water is projected to be heated and borated, provides assurance that the stored trisodium phosphate will dissolve as required following a LOCA. The sample storage racks are sized to contain 0.5 pounds of trisodium phosphate. Trisodium phosphate stored in the sample storage racks has a surface area to volume ratio of 1.33 whereas the trisodium phosphate stored in the main racks has a surface area to volume ratio of 1.15.
Visual inspection of the non-redundant piping in the Containment Spray System provides additional assurance of the integrity of that system.
REFERENCES:
(1) Final Engineering Report and Safety Analysis, Paragraph 5.1.
(2) "San Onofre Nuclear Generating Station", report forwarded by letter dated December 29, 1971 from Jack B. Moore to 34 Director-, Division of Reactor Licensing, USAEC, subject:
4/1/77 Emergency Core Cooling System Performance, San Onofre Nuclear Generating Station, Unit 1.
(3) USAEC Safety Evaluation of ECCS Performance Analysis for San Onofre Unit 1, forwarded by letter dated March 6, 1974 from Mr. Donald 3. Skovholt to Mr. Jack B. Moore.
(4) Letter, K. P. Baskin, SCE, to D. M. Crutchfield, NRC, 114 dated October 16,- 1981.
11/18/88 SAN ONOFRE -
UNIT 1 4-39a Revised:
12/9/88 PROPOSED TECHNICAL SPECIFICATION 3.3 SAFETY INJECTION AND CONTAINMENT SPRAY SYSTEMS 3.3.1 OPERATING STATUS APPLICABILITY:
Applies to the operating status of the Safety Injection and Containment Spray Systems.
OBJECTIVE:
To define those conditions necessary to ensure availability of the Safety Injection and Containment Spray Systems.
SPECIFICATION:
A. The reactor shall not be made or maintained critical unless the following conditions are met. In addition, the reactor coolant system temperature shall not be increased above 200*F unless the containment spray system, the refueling water storage tank and the associated valves and interlocks are operable.
(1) Safety Injection Systems
- a. Refueling tank water storage and boron concentration comply with Specification 3.3.3.
- b. ESF Switchover automatic trip channel is OPERABLE with the setpoint less than or equal to 20% and greater than or equal to 18% of RHST level.
- c. Two safety injection pumps are OPERABLE.
- d. Two feed water pumps are OPERABLE.
- e. Two recirculation pumps are OPERABLE, except as indicated in item D below.
- f. The recirculation heat exchanger is OPERABLE.
- g. Two charging pumps are OPERABLE.
- h. Two component cooling water pumps are OPERABLE.
- i.
Two saltwater cooling pumps are OPERABLE. The reactor may be maintained critical with one saltwater cooling pump provided the auxiliary saltwater cooling pump or two screen wash pumps are available as backup. Return the inoperable pump to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. The backup pump(s) shall be demonstrated operable by test within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of declaring the saltwater cooling pump inoperable.
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- j. A minimum of 5400 pounds of anhydrous trisodium phosphate is stored in the containment sump in racks provided.
(2) Containment Spray System
- a. Two refueling water pumps are OPERABLE.
- b. Two hydrazine additive pumps are OPERABLE.
- c. Hydrazine tank level and hydrazine concentration comply with Specification 3.3.4.
(3) Valves and interlocks associated with each of the above systems are OPERABLE.
(4) Effective leakage from the recirculation loop outside the containment shall be less than 625 cc/hr as calculated from the following formula.
Effective Leakage = al x L1 + a2 x L2 + a3 x L3
- where, L1 -
pump and valve leakage which drains to auxiliary building sump L2 -
valve leakage in auxiliary building or doghouse L3 =
valve leakage outside al -
iodine release factor for leakage in auxiliary building sump a2 =
iodine release factor for leakage in auxiliary building or doghouse a3 = iodine release factor for leakage outside the auxiliary building or doghouse If effective leakage from the recirculating loop outside the containment exceeds 625 cc/hr, make necessary repairs to limit leakage to 625 cc/hr.
within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in COLD SHUTDOWN within the next 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
B. During critical operation or when the reactor coolant system temperature is above 200*F, as appropriate per Item A above, maintenance shall be allowed on any one of the following items at any one time:
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(1) One motor-operated valve at a time (MOV 1100B or 1100D) in the recirculation loop upstream of the charging pump suction header for a period of time not longer than 72 consecutive hours.
(2) One refueling water pump and/or its associated discharge valve at a time, for a period not longer than 72 consecutive hours.
(3) One hydrazine pump and/or its associated discharge valve (SV600 or 601) at a time, for a period of time not longer than 72 consecutive hours.
(4) One charging pump for a period of time not longer than 72 consecutive hours.
(5) One of the two required component cooling water pumps for a period of time not longer than 72 consecutive hours.
(6) One of the two saltwater cooling pumps with the auxiliary saltwater cooling pump or screen wash pumps available as backup for a period of time not longer than 72 consecutive hours.
The backup pump(s) shall be demonstrated operable by test within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of declaring the saltwater pump inoperable.
(7) One train of ESF switchover automatic trip for a period of time not to exceed 72 consecutive hours.
C. Prior to initiating maintenance on any of the components, the duplicate (redundant) component shall be tested to demonstrate availability.
D. In the event of a failure of a recirculating pump, plant operation may continue provided operability of the remaining pump and its associated motive and control power are satisfactorily demonstrated on a daily basis, including verification that the containment spray bypass valves (CV517 and 518) are closed.
BASIS:
The requirements of Specification A assure that before the reactor can be made critical, or before the reactor coolant system heatup is initiated, adequate engineered safeguards are operable. The limit of 625 cc/hr for the recirculation loop leakage ensures that the combined 0-2 hr EAB thyroid dose due to recirculating loop leakage and containment leakage will not exceed the limits of 10 CFR 100. The formula for determining the leakage incorporates consideration of the significance of leakage in different plant areas. The iodine release factor adjusts actual pump or valve leakage to account for the fraction of the iodine in 3-30
the leakage which would actually be released to the atmosphere. The iodine release factors in the auxiliary building sump, the auxiliary building or doghouse, and outside are 0.05, 0.5, and 1.0, respectively.
When the reactor is critical or the reactor coolant system temperature is above 2000F, maintenance is allowed per Specifications B and C providing requirements in Specification C are met which assure OPERABILITY of the redundant component. The specified maintenance times are a maximum, and maintenance work will proceed with diligence to return the equipment to an operable condition as promptly as possible. OPERABILITY of the specified components shall be based on the results of Specification No. 4.2.
The allowable maintenance periods are based upon the repair of certain specific items.
Based on the demonstration that equipment redundant to that removed from service is OPERABLE, it is reasonable to maintain the reactor at power over this short period of time.
In the unlikely event that the need for safety injection should occur:
functioning of one train will protect the core.()(2)(3)(4)
Containment sprays alone, however will maintain containment pressure under design pressure.(53
-- functioning of one of the two hydrazine additive pumps and associated discharge valve will effect introduction of hydrazine into containment spray water. This provides for absorption of airborne fission products and reduction of the thyroid doses associated with the maximum hypothetical accident to within 10 CFR 100 limits.
-- dissolution of 5400 pounds of anhydrous trisodium phosphate stored in the sump will ensure that the pH of the water in the sump will be greater than 7 within four (4) hours, so as to prevent chloride stress corrosion cracking of systems and components exposed to the circulating sump water.
In the event of inoperability of a recirculation pump, plant operation may continue since either pump is sufficient and a daily OPERABILITY demonstration of the remaining pump and its associated motive and control power provides assurance that it will be OPERABLE if required.
The switchover from injection to recirculation modes is a two part process, which consists of the automatic termination of 3-31
the flow from SSI/FW pumps including automatic pump trip and auto closure of MOV's 850 A, B and C followed by manual realignment to recirculation from the containment sump.
The automatic trip setpoint is bounded by the minimum water level in the sump to support recirculation for long term post-LOCA cooling and the minimum RWST level to support charging and containment spray during the manual realignment. The setpoint analysis conservatively determined the automatic trip setpoint to be 20% of the RWST level.
The automatic trip setpoint is the result of the combination of the worst single active failure condsidering SIS and SISLOP conditions.
REFERENCESS:
(1) Final Engineering Report and Safety Analysis, Paragraph 10.1.
(2) Final Engineering Report and Safety Analysis, Paragraph 5.1.
(3) "San Onofre Nuclear Generating Station," report forwarded by letter dated December 29, 1971, from Jack B. Moore to Dirctor, Division of Reactor Licensing, USAEC, subject:
emergency Core Cooling System Performance, San Onofre Nuclear Generating Station, Unit 1.
(4) USAEC Safety Evaluation of ECCS Performance Analysis for San Onofre Unit 1, forwarded by letter date March 6, 1974, from Mr. Donald J. Skovholt to Mr. Jack B. Moore.
(5) Supplement No. 1 to the Final Engineering Report and Safety Analysis, Section 5, Question 3c.
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74.2 SAFETY INJECTION AND CONTAINMENT SPRAY SYSTEM 4.2.1 SAFETY INJECTION AND CONTAINMENT SPRAY SYSTEM PERIODIC TESTING APPLICABILITY:
Applies to testing of the Safety Injection System and the Containment Spray System.
OBJECTIVE:
To verify that the Safety Injection System and the Containment Spray System will respond promptly and properly if required.
SPECIFICATION:
I. System Tests A. Hot Safety Injection System Test (1) When the plant is planned to be shutdown from MODE 1 operation and is planned to enter MODE 5 operation, a Hot SIS Test shall be performed in MODE 3 while RCS pressure is above 1500 psi but not more often than once every 9 months. The test shall include a determination of the force required to open valves NV 851 A and 8 and the margin of available actuation force.
(2) The test will be considered satisfactory if:
(a) control board indication and visual observations indicate all components have operated and sequenced properly. That is, the appropriate pumps have started and/or stopped and started, and all valves have completed their travel.
(b) the measured actuator force for both the HV-851 A and B valves is equal to or less than 10,000 lbf.*
(3) If the measured actuator force of either HV-851 A or B is between 10,000 and 22,000 lbf, the HV-851 A and B valves shall be considered OPERABLE but the future testing interval shall be accelerated as determined by the following equation:
- Upon receipt of satisfactory data from continuing testing and analysis, the NRC staff will consider a request from Southern California Edison Company to change this number to more accurately reflect existing conditions.
T = T L (22,000 - F) 12,000 where:
T = maximum time in days of operation allowed before next surveillance test is required T L = time in days of operation since the last surveillance test F =
measured actuator force (4) If the measured actuator force of either HV-851 A or 8 is greater than 22,000 lbf, test results shall be reported to the NRC pursuant to Specification 6.9.2 along with proposed corrective actions.
NRC approval shall be obtained prior to returning the unit to service.
B. Trisodium Phosphate Test (1) A test of the trisodium phosphate additive shall be conducted once every refueling to demonstrate the availability of the system. The test shall be performed in accordance with the following procedure:
(a) The three (3) storage racks are visually observed to have maintained their integrity.
(b) The three (3) racks, each with a storage capacity of 1800 pounds of anhydrous trisodium phosphate additive, are visually observed to be full.
(c) Trisodium phosphate from one of the sample storage racks inside containment shall be submerged without agitation, in 25+0.5 gallons of 150OF to 175 0F distilled water borated to 3900+100 ppm boron.
(2) The test shall be considered satisfactory if the racks have maintained their integrity, the racks are visually observed to be full, and the trisodium phosphate dissolves to the extent that a minimum pH of 7.0 is reached within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of the start of the test.
C. Containment Spray System Test (1) During reactor shutdown at intervals not longer than the normal plant refueling intervals, a "no-flow" system test shall be conducted to demonstrate proper availability of the system. The test shall be performed either by closing a manual valve in the system or electrically disabling the refueling water pumps and initiating the system by tripping the normal actuation instrumentation.
(2) The test will be considered satisfactory if visual observations indicate all components have operated satisfactorily.
(3) At least once every second refueling outage an air flow test shall be performed to demonstrate the absence of blockage at each containment spray nozzle.
II. Component Tests A. Pump Tests (1) In addition to the above test, the safety injection, recirculation, spray additive and refueling water pumps shall be started at intervals not to exceed one month to verify that they are in satisfactory running order.
(2) Acceptable levels of performance shall be as follows:
(1) The safety injection pumps shall reach and be capable of maintaining 95% of their rated shutoff head within 10 seconds after starting.
(2) The refueling water pumps shall be capable of maintaining 90% of their rated shutoff head.
(3) The recirculation pumps shall be run dry.
Proper starting of the pump is confirmed by observation of the running current on the ammeter.
(4) The spray additive pumps shall be capable of maintaining their rated flow at a discharge pressure not less than 90% of their rated discharge pressure.
B. Leakage Testing (1) The recirculation loop outside containment (including the Containment Spray System) shall be pressurized at a pressure equal to or greater than the operating pressure under accident conditions at intervals not to exceed the normal plant refueling interval.
Visual inspections for leakage shall be made and if leakage can be detected, measurements of such leakage shall be made. In addition, pumps and valves of the recirculation loop outside containment which are used during normal operation, shall be visually inspected for leakage at intervals not to exceed once every six months. If leakage can be detected, measurements of such leakage shall be made.
(2) The non-redundant Containment Spray System piping shall be visually inspected at intervals not to exceed the normal plant refueling interval.
Observations made as part of compliance with Paragraph C, above, or Paragraph I.C(2) of Technical Specification 4.2 will be acceptable as visual inspection of portions of non-redundant Containment Spray System piping.
C. RWST Low Level Trips Monthly, perform a CHANNEL TEST and every refueling interval, perform a CHANNEL CALIBRATION, of the SI/Feedwater Pump trip and the MOV 850A, 850B and 850C automatic closure on low-low Refueling Water Storage Tank level.
BASIS:
The Safety Injection System is a principal plant safeguard.
It provides means to insert negative reactivity and limits core damage in the event of a loss of coolant or steam break accident.
(1)(2)(3)
Preoperational performance tests of the components are performed in the manufacturer's shop.
An initial system flow test demonstrates proper dynamic functioning of the system.
Thereafter, periodic tests demonstrate that all components are functioning properly. For these tests, flow through the system is generally not required. However, in the case of the "Hot SIS Test," actual conditions of an SI event are simulated. This test is performed to assure that long-term set of the valve seat faces on HV-851 A and 8 has not caused the valves to become inoperable. The test is required to be performed as the plant is shutting down from MODE 1 in order to assure that the valves have not been disturbed (i.e., the long-term set is still in effect) and that full dynamic conditions that would occur during an actual SI event are simulated. When possible the test should be performed prior
to stopping the feedwater pumps (this is not a requirement).
This will further assure that the valves will be in the same condition as when required for an actual Safety Injection event since the discharge pressure of the feedwater pumps acting on the valves will keep them seated even considering any backpressure built up in the downstream SI header. The equation used to determine future intervals if actuator force is between 10,000 lbf and 22,000 lbf is developed by shortening the interval in direct proportion to the degree to which the force exceeds 10,000 lbf.
During the test, all components are verified to have operated and sequenced properly.
The tests required in this specification will demonstrate that all components which do not normally and routinely operate will operate properly and in sequence if required.
The portion of the Recirculation system outside the containment sphere is effectively an extension of the boundary of the containment. The measurement of the recirculation loop leakage ensures that the calculated EAB 0-2 hr. thyroid dose does not exceed 10 CFR 100 limits.
The trisodium phosphate stored in storage racks located in the containment is provided to minimize the possibility of stress corrosion cracking of metal components during operation of the ECCS following a LOCA. The trisodium phosphate provides this protection by dissolving in the sump water and causing its final pH to be raised to 7.0 - 7.5.
The requirement to dissolve trisodium phosphate from one of the sample storage racks in distilled water heated and borated, to the extent recirculating post LOCA sump water is projected to be heated and borated, provides assurance that the stored trisodium phosphate will dissolve as required following a LOCA. The sample storage racks are sized to contain 0.5 pounds of trisodium phosphate. Trisodium phosphate stored in the sample storage racks has a surface area to volume ratio of 1.33 whereas the trisodium phosphate stored in the main racks has a surface area to volume ratio of 1.15.
Visual inspection of the non-redundant piping in the Containment Spray System provides additional assurance of the integrity of that system.
Surveillance testing of the RWST low-low level main feedwater/safety injection pump trips and automatic closure of MOV 850A, 850B and 850C valves will ensure that these components will be available to complete their safety functions if required.
r*
e
REFERENCES:
(1) Final Engineering Report and Safety Analysis, Paragraph 5.1.
(2) "San Onofre Nuclear Generating Station", report forwarded by letter dated December 29, 1971 from Jack B. Moore to Director, Division of Reactor Licensing, USAEC, subject:
Emergency Core Cooling System Performance, San Onofre Nuclear Generating Station, Unit 1.
(3) USAEC Safety Evaluation of ECCS Performance Analysis for San Onofre Unit 1, forwarded by letter dated March 6, 1974 from Mr. Donald 3. Skovholt to Mr. Jack B. Moore.
(4) Letter, K. P. Baskin, SCE, to D. M. Crutchfield, NRC, dated October 16, 1981.
0748n