ML13330B201
| ML13330B201 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/28/1987 |
| From: | Medford M SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| GL-83-28, NUDOCS 8705060096 | |
| Download: ML13330B201 (5) | |
Text
Southern California Edison Company P. 0.
BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 M. O. MEDFORD TELEPHONE MANAGER OF NUCLEAR ENGINEERING (818) 302-1749 AND LICENSING April 28, 1987 U.S. Nuclear Regulatory Commission Attention:
Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206 Generic Letter 83-28 Item 1.2 - Data and Information Capabilities San Onofre Nuclear Generating Station Unit 1
Reference:
July 15, 1986 letter from M.0.Medford, SCE, to G.E.Lear, NRC, Regarding Generic Letter 83-28.
The referenced letter provided information to supplement our previous submittals relating to the Post-Trip Review Data and Information Capabilities at San Onofre Unit 1 (November 28, 1983 and January 21, 1986).
Discussions between SCE and NRC staff reviewers identified the need to provide clarification of the information provided in the referenced letter. The specific areas in which clarification is needed include the time discrimination of the events recorder strip chart, analog data sampling intervals, and discrepancies between NRC desired recording capabilities and actual recording capabilities at San Onofre Unit 1.
In regards to the time discrimination of the events recorder strip chart, the recorder has discrimination of 100 msec or better. This discrimination can be verified by review of the actual strip charts provided to the NRC by the referenced letter and by our letter dated January 21, 1986. Subsequent to a trip signal, the chart will run at high speed (3600 times normal speed) for 24 seconds. The minimum paper supply will be maintained sufficient for three high speed runs.
The next item requiring clarification deals with the analog data sampling intervals for parameters on the FOX-3. The NRC review criteria for analog data sampling is at least once every 10 seconds. All of the parameters on the FOX-3, with the exception of composite analog values, are scanned more frequently than 10 seconds. The composite analog values, Sections IV and V of Table 1, are not part of the Post-Trip Review. Therefore, the frequency at which these values are scanned and stored is not applicable to Generic Letter 83-28, Item 1.2.
For clarification, a list of FOX-3 parameters with scan rates is provided in Table 1.
8705060096 870428 PDR ADOCK 05000206 P
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Southern California Edison Company Document Control Desk April 28, 1987 The final item requiring clarification deals with the desired versus existing recording capability for Post Trip Review parameters. The NRC staff concern in this area is the lack of recording capability at San Onofre Unit 1 for several of the desirable parameters. Table 2 illustrates the existing recording capability for the Post-Trip Review parameters. It is noted that further review of the recording capabilities at San Onofre Unit 1 has identified that 2 of the parameters previously identified in the referenced letter as having no recording capability do have control room data recorders.
These parameters are control rod position and containment radiation. The remaining parameters without direct recording capability include Reactor Coolant Pump Status and AC and DC System Status. Reactor coolant pump bearing temperature is recorded and provides indirect indication of pump status.
The San Onofre Unit 1 Safety Parameter Display System (SPDS) is currently in the conceptual design stage. Once installed the SPDS will provide indication for many of the Post-Trip Review parameters. The current design includes indication of reactor coolant pump status and all 120V AC Vital Buses. Table 2 illustrates the recording capability for the Post-Trip Review parameters.
Additionally, Table 2 indicates the parameters currently scheduled to be included in the SPDS.
In regards to the post trip review function of the FOX-3, it is noted that the program has been revised to include 10 minutes of post-trip data, as opposed to 5 minutes, as desired by the NRC review criteria.
If you have any questions or require additional information, please let me know.
Very truly yours, cc: J. B. Martin, Regional Administrator, NRC Region V F. R. Huey, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3 R. F. Dudley, NRR Project Manager, San Onofre Unit 1
Table 1 FOX-3 Parameter Scan Rates I. Analog Inputs Scanned at One Second Rate NIS 1206 Power Range Indication NIS 1201 Source Range Indication RCS T-Hot Loop A RCS T-Hot Loop B RCS T-Hot Loop C Containment Pressure (Wide Range)
Steam Header Pressure Sphere Sump Level Containment Water Level Steam Generator Level Loop A (Wide Range)
Steam Generator Level Loop B (Wide Range)
Steam Generator Level Loop C (Wide Range)
Pressurizer Pressure Pressurizer Level The above parameters are stored at one second intervals in a thirty minute circular file for the Fast Post Trip Review Report. They are also stored at one minute intervals in the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> circular history files.
II. Analog Inputs Scanned at a Five Second Rate Containment Hydrogen Concentration Charging Line Flow Rate Safety Injection Recirc Flow Rate Loop A Safety Injection Recirc Flow Rate Loop B Safety Injection Recirc Flow Rate Loop C Recirc Pump Flow G-45A Recirc Pump Flow G-45B Containment Spray Flow Rate Safety Injection Flow Loop A Safety Injection Flow Loop B Safety Injection Flow Loop C Aux Feedwater Flow Loop A Aux Feedwater Flow Loop B Aux Feedwater Flow Loop C Aux Feedwater Storage Tank Level Refueling Water Tank Level Incore Thermocouple Cll Note: These incore thermocouples are Incore Thermocouple D5 temporarily disabled pending Incore Thermocouple Fll resolution of the environmental Incore Thermocouple F5 qualification status of these Incore Thermocouple Kll inputs to the subcooled margin Incore Thermocouple L4 monitor.
Incore Thermocouple M13 Incore Thermocouple N6 The above parameters are stored at one minute intervals in the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> circular history files.
Table 1 (Cont.)
III. Digital Inputs Scanned at a One Second Rate Reactor Trip Containment Isolation Initiation Safety Injection Initiation CV530 PORV Block Valve CV531 PORV Block Valve RV532 Pressurizer Safety Valve RV533 Pressurizer Safety Valve CV545 Pressurizer Relief Valve CV546 Pressurizer Relief Valve Digital contact change of state is recorded on hardcopy printout upon occurrence. They are also stored at one minute intervals in the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> circular history files.
IV. Composite Analog Values Computed at Five Second Intervals THOT Saturation Temperature (TSAT)
Margin to Saturation Temperature RCS Heatup/Cooldown Temperature Rate of Change Total Safety Injection Loop Flow Total Safety Injection Recirc Flow Total Recirc Pump Flow Total Aux Feedwater Flow The above parameters are stored at one minute intervals in the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> circular history files.
V. Composite Analog Values Computed at 60 Second Intervals Effective Full Power Days (EFPD)
Megawatt Days per Metric Ton U-235 Xenon Reactivity Xenon Reactivity Rate of Change Maximum Containment Pressure Xenon reactivity and maximum containment pressure are recorded at one minute intervals in the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> circular history files.
TABLE 2 POST-TRIP REVIEW PARAMETERS Events Control Room (8)
Parameter/Signal Recorder Data Recorder FOX-III SPDS Reactor Trip X
X Safety Injection X
X Containment Isolation X
X Turbine Trip X
Control Rod Position X
X Neutron Flux, Power X
X X(7)
X Containment Pressure X
X Containment Radiation X
X Containment Sump Level X(7)
X RCS Pressure X
X X(7)
X RCS Temperature X
X(7)
X Pressurizer Level X
X X(7)
X Reactor Coolant Pump Status X(l)
X RCS Flow(2)
Safety Injection Flow X(3)
X X
MSIV Position(4)
Steam Generator Pressure X
X(7)
X Steam Generator Level X
X X(7)
X Feedwater Flow X
X Steam Flow X
X AFWS Flow X(7)
X AC and DC System Status X(5)
DG Status(6)
X PORV Position X
X (1) Reactor coolant pump status is not directly recorded. RCP bearing temperature is recorded and provides indirect indication of pump status.
(2) RCS Flow is not recorded directly. However, loss of RCS flow is indirectly indicated on the events recorder by the RCS reduced power low flow scram and full power low flow scram channels.
(3) SI Pump bearing temperature (provides indirect indication of pump status).
(4) Parameter not applicable to San Onofre Unit 1.
(5) AC and DC System Status are not currently recorded but vital bus status will be included in the San Onofre Unit 1 Safety Parameter Display System.
(6) DG status is not recorded directly. However, the DG's are automatically started during a safety injection actuation. SI initiation is recorded on the FOX-III and the events recorder.
(7) Parameter included in the Post-Trip Review function of the FOX-III (8) Parameters on SPDS are based on current conceptual design. Actual parameters will be established during final design stage.