ML20011F424
| ML20011F424 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 02/26/1990 |
| From: | Eddy J CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-83-28, NUDOCS 9003060010 | |
| Download: ML20011F424 (16) | |
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Consumers Power rewcams ASKMEAN'S MISERc55 oeneret offices: 1946 West Pernett Road, Jackson, MI 49201 e (617) 788 0660 February 26, 1990 Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLANT -
RESPONSE TO A REQUEST FOR ADDITIONAL INFORMATION FOR GENERIC LETTER 83-28, ATWS ITEM 1.2 This letter provides Consumers Power Company's response to an NRC Request for Additional Information (RAI) dated November 20, 1989, concerning Generic Letter 83-28. Generic Letter 83-28, " Required Actions Based on Generic Implications of Salem ATWS Events", dated July 8, 1983, requested information concerning Big Rock Point's capability to record, recall, and display data and information to permit diagnosing the causes of unscheduled reactor shutdowns.
Consumers Power Company's response to the Generic Letter for Big Rock Point was submitted on November 7, 1983. A draft Technical Evaluation Report (TER) for Salem ATWS Item 1.2 was sent to Consumers Power Company on November 18, 1985.
The draft TER provided a list entitled " Desirable BWR Parameters for Post-Trip Review", that list has been provided as Attachment I to this letter. The list circles those parameters the reviewers determined were not recorded according to Consumers Power Company's response to the Generic Letter, dated November 7, 1983. The referenced RAT requested that Consumers Power Company review the Ifst and provide information as to how the circled parameters are recorded at g
Big Rock Point.
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Big Rock Point P3 ant Addt'l Info on CL 83-28 February 26, 1990 to this letter provides more detailed information regarding Big Rock Point's capability to handle data and information used to diagnose the causes of ATWS events. Consumers Power Company concludes that the information provided herein is adequate to nect the intent of the review criteria of Generic Letter 83-28. This information was previously discussed with the Project Manager and Technical Reviewer during a telephone conference on November 26, 1985.
QM kYf J Daniel Eddy Plant Licensing Engineer CC Administrator, Region III, USNRC NRC Rest'ent Inspector - Big Rock Point Attachments k
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i ATTACHMENT 1 Consumers Power Company Big Rock Point Plant Docket 50-155 DESIRABLE BWR PARAMETERS FOR POST TRIP REVIEW (From Draft TER, dated November 26, 1985)
February 26, 1990 1
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Desirable BWR Parameters for Post-Trip Review (circled parameters are not recorded) l SOE Time History Retarder
- jtstrfte, Parameter / Sienal l-Reactor Trip Safety Injection Containment Isolation Turbine Trip a
Control Rod Position x (1)
Neutron Flux, Power
@(1)
Main Steam Radiation (2)
Containment (DryWell) Radiation x (1)
Drywell Pressure (Containment Pressure)
Suppression Pool Temperature x (1)
Qx Primary System Pressure x (1)
Qx Primary System Level x
MSIV Position x (1)
Turbine Stop Valve / Control Valve Position Turbine Bypass Valve Position 8x Feedwater Flow x
Steam Flow (3)
Recirculation; Flow. Pump Status x (1)
Scram Discharge Level x(1)
Condenser Vacuum
@ @ (4)
AC and DC System Status (Bus Voltage)
Safety Injection; Flow. Pump / Valve Status Diesel Generator Status (On/0ff, Start /Stop) l (1): Trip parameters.
(2): Parameter may be recorded by either an SOE or time history recorder.
(3): Acceptable recorder options are: (a) system flow recorded on an SOE recorder, (b) system flow recorded on a time history recorder, or (c)equipmentstatusrecordedonanSOErecorder.
(4): Includes recording of parameters for all applicable systems from the following:
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ATTACHMENT 2 L
Consumers Power Company Big Rock Point Plant Docket 50-155 i
ADDITIONAL INFOPyATION FOR GENERIC LETTER 83-28. ATWS ITEM 1,2 L
February 26, 1990 i
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ADDITIONAL INFORMATION FOR GENERIC LETTER 83-28. ATWS ITEM 1.2 As requested, more detailed information is being provided regarding Big Rock Point's capability to handle data and information used to diagnose the causes of ATWS events.
Specifically, the following topics are discussed:
- A description of identified reactor parameter monitoring.
- A more complete description of the data capabilities at Big Rock Point.
- A description of our data retention procedures.
REACTOR PARAMETER MONITORING A list of desirable BWR parameters for post-trip review was provided in the draft Technical Evaluation Report (TER November 26, 1985, see Attachment 1).
An evaluation of how Big Rock Point monitors the parameters specified in the TER follows, in addition, supplementary information on the recorders that provide this information follow.
Reactor Trip The operational recorder at Big Rock consists of four strip chart event recorders. These recorders operate at approximately 1.5 inches per hour until triggered by a trip of any reactor protection system (RPS) input, at that time the recorders speed increases to approximately 1.5 inches per minute.
The response time of the recorder is on the order of 10-50 milliseconds.
When any reactor trip signal is generated, the corresponding pen deflects approximately 1/10th of an inch to indicate de-enerization of the trip switch. The recorder will continue to advance at the accelerated rate for approximately 5 minutes or until the RPS is reset.
In addition to the RPS trip input signals, the operational recorder also monitors the voltage to the scram pilot valves and the relay coil voltage that controls the closure of the dump tank isolation valves through K3 and K5 contacts. The recorders are powered from the safety related panel lY.
i The trip inputs monitored and recorded are
- High reactor building pressure g
- Low reactor water level l
- High reactor pressure 1
- Recirculation valve partial closure f
- Main steam isolation valve partial closure
- High scram dump tank level
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- Wide range power monitor Channel 1
- Wide range power monitor Channel 2 l
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- Wide range power monitor Channel 3
- High condenser pressure
- Lov steam drum water level
- APS Relay K3
- RPS Relay K4
- RPS Relay K5 Safety Injection (Initiation)
Big Rock Point's safety injection system is referred to as the Core Spray System. When the reactor is depressurized to below fire system pressure (approximately 110 psi) the two trains of core spray allow fire water to flow into the reactor to keep the core covered.
Initiation can be verified by several indications.
Station annunciator 60-Core spray valve open alarm, annunciator 3A-Core spray flow alarm and annunciator 4A-Core spray backup valve flow alarm verify the initiation of the core spray system.
The core. spray valve position lights will change colors when the valves are open. The core spray valves and position lights are powered from the 125V de distribution panel and safety related Bus 2B, depending upon which train is actuated.
In addition, core spray flow is recorded on strip chart FR-2108. An Acco-Bristol 5" paper strip chart scaled at 0-900 gpm, and traveling at 1"/hr.
The strip chart starts moving when any core spray valve opens.
Fire pump running is detected by the Fire Station Annunciator panel. The appropriate indicator will light and the bell alarm will scund. These indications are recorded in the control room logbook.
In addition, fire system pressure is recorded on a 7" circular chart.
Containment Isolation
.The containment isolation valve position is not recorded at Big Rock. The Scram proceduro (ONP-2.31) directs the operators to check for vent valve closure upon every scram. Big Rock has a continuously vented reactor building.
In addition, the operator checks for isolation valve closure if the scram was an isolation scram.
The isolation valve position lamps are arranged in a functional group and so labeled.
It is easy to determine the valve's position by looking at this ar. cay. Any failure to close would be documented in the g'
control room logbook. Since the isolation valves are only expected to change i
position once during the transient, a continuous or intermittent record of i
their position is not necessary.
For reconstruction of the transient, the information recorded in the control room logbook will suffice in determination of all isolation valve positions.
Information with respect to time of the isolation initiation can be obtained from the Operational Recorder associated with the Reactor Protection System (RPS relays K3, K4, and K5).
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Turbine Trip Turbine trips are monitored and recorded on TSR-7300 and TSR-7301, the Turbine Admissions Valves Position and Turbine Speed recorder. The General Electric
- recorder has 5" paper scaled at 1-100% valve position. 0-5000 rpm. The admission valve position is recorded until the main generator output oil breaker (116 OCB) opens, it then switches to turbine speed.
Turbine trips can also be traced by the Plant Electric Power Output Recorder (Net Mw). The 5" paper is scaled at 0-100 Mw.
The cause of the turbine trip can possibly be deduced from the turbine annunciators prior to the trip. The turbine annunciators are as follows:
1-Excess vibration, 2-Turbine thrust bearing excess wear, 3-Turbine hi eccentricity, 10-Turbine lube oil resevoir lo-high alarm, 12-Turbine generator bearing oil temperature, 19-Turbine bearing oil low pressure, 20-Turbine overload and 21-Turbine excess expansion.
Neutron Flux Power 1
The wide range monitor flux level recorders (RR-RIOSC, RR-RIO5B and RR-RIOSA) are dual pen 12" syrip chart recorders.
The blue pen records flux 1cvel over a log range of 10 to 150% power, the red pen becomes active at 1% power and records flux level over a linear range of 1 to 150% power.
The chart speed is 6"/hr.
The source range recorders (RR-RH06A and RR-RH06B) are dual pen 12" strip chart recorders. The blue pen records counts per second over a seven eyilo log range of IE-1 to IE-6.
The red pen is selectable, either off gas seenvity or the dunker. The dunker is a portabic neutron monitoring probe useC dteing refueling. The recorder is scaled over a six cycle log range of 1 to IE-6 units. The red pen is usually selected to off gas activity.
The chart speed is 6"/hr.
These charts, in combination, provide the power level / neutron flux data necessary for reconstruction of a transient in a usable and readable manner.
Main Steam Radiation Main steam radiation is not directly monitored or recorded. An indication of the radioactivity in the main steam is available from several sources.
Radiation levels throughout the plant increase as steam line radiation increases. An immediate increase would be detectable by the Air Ejector Off Gas System which is designed to detect noble gas fission products indicative of a_ fuel element rupture.
Indications from the Air Ejector Off Gas System are available on the source range /off gas recorders (RR-RH06A RR-RH06B) mentioned above. This is a continuous monitoring system and data would he available to pinpoint the time and quantity of the radiation increase.
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l Another indication of increased main steam radiation is the stack gas monitor system, also called the Radioactive Gaseous Effluent Monitoring System (RGEMS',.
This system receives a representative sample of plant gaseous effluet.i ine the plant stack during normal and accident conditions. During normal conditions the sample is monitored for particulates/radiciodine and noble gases. During abnormally high levels of activity in the effluent, the system bypasses the normal range detectors and automatically takes a grab sample, switches to r.
high range gamma detector for noble gas activity and a high range Intrinsic Germanium detector for particulate /radiciodine filter activity.
Normal range particulate /radiciodine activity and noble gas' activity are recorded on RR-8057. Upon a high activity alarm from normal range noble gas indicator RI-8327, the high range noble gas recorder RR-8058 shifts to fast speed in anticipation of a high-high activity condition.
The Area Monitoring System can be used to detect increases in main steam radiation in areas outside containment. No credit is taken for this system inside containment because it is not LOCA qualified. The area monitor radiation levels are recorded by RR-8053, a 12" paper strip chart scaled at 1-103 mR/hr. One point is recorded every 3 seconds. There are 19 pens. The chart travels at 4"/ hour.
Through the use of the above mentioned recorders, data can be reconstructed to determine the time and amount of radioactivity increase in the steam line.
Containment Pressure The containment pressure is continuously recorded on two containment level / pressure recorders, each utilizing one level and one pressure indicator (LR-3110 LR-3111, PR-53, and PR-54). The 5" strip chart is scaled for level at 572' to 598' and for pressure at 0-100 pai. The chart moves at approximately 1/4"/hr.
Suppression Pool Temperature Big Rock Point has no suppression pool, Controlled reactor depressurization is directed or contained within the steam drum enclosure /recirc pump room located within containment. Temperature within containment is recorded on TR-9623.
The 8" paper strip chart is scaled 0-120*P.
The paper travels at approximately ll"/hr and records one point every three seconds. There are 12 points.
Primary System Pressure Primary system pressure is continuously recorded on the 12" reactor pressure circular chart PR-1A09 scaled at 100-2000 psi.
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i Primary System Level Primary system level is continuously monitored, displayed and annunciated by LI-3380 through LI-3387. The first four level indicators represent the level in the reactor vessel and the second four represent the level in the steam drum. Steam drum level is continuously recorded on the 12" steam drum icvel circular chart LR-lD12 scaled f rom -25" to +25.
Big Rock Point operates with the primary system level at about centerline of i
the steam drum. Primary system level is maintained in the steam drum for the majority of plant trips and transients.
For large break loss of coolant accidents, IcVel may decrease below the drum and may or may not be maintained in the reactor vessel. During these accidents, the important parameter to monitor is safety injection flow, not reactor vessel level.
Safety injection flow recorder FR-2108 was discussed earlier. Documentation of the vessel inventory reaching the 2' 9" Icvel (safety limit) can be obtained from the Operational Recorder.
Turbine Bypass Valve Position The turbine bypass valve position is not directly recorded. Determination of open or closed position can be made based on steam flow, reactor pressure and steam drum Icvel. These parameters are continuously monitored and recorded on the 12" circular charts, FR-ID06 scaled 0-1,000,000 lb/hr, PR-1A09 scaled 100-2000 psi and LR-ID12 scaled 25" to +25" respectively.
Feedwater Flow Feedwater flow is continuously monitored and recorded on the 12" Feedwater flow circular chart FR-lD07 ecaled 0-1,000,000 lb/hr.
Steam Flow Steam flow is continuously monitored and recorded on the 12" Steam Flow
' circular chart FR-ID06 scaled 0-1,000,000 lb/hr powered by panel lY.
Ac and De System Status n.ts Voltage) 2400 ac bus annunciates on incoming breaker trips and system ground faults.
2400v ac frequency and voltage is monitored on the control console and is recorded hourly by the control operators on the control room log sheets.
480v ac ground alarms are annunciated also.
Emergency Bus 2B frequency and voltage are also monitored on the control console.
125v de voltage readings are taken every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and recorded on the station battery log sheet.
In addition, the voltage is monitored by a white light above the annunciator panel, alerting the control operators to low voltage on the system, as well as a 125v de trouble alarm.
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6 No continuous record of power system response is available or deemed necessary.
9 Safety injection (Lonn term) 5 Safety injection system at Big Rock Point for long term cooling includes additional pleecs of equipment mentioned previously in the safety injection initiation section. When the containment building water level reaches a certain level, as indicated on the containment water level / pressure recorder, safety injection is terminated and post incident recycling commences. This is a manually initiated system and initiation would be recorded in the control room logbook.
The station annunciators monitor the following parameters; 46-Core spray pump discharge pressure 10, 5A-core spre' heat exchanger strainer flow below normal and 6A-core spray heat exchanger 1.ugged.
The core spray pupp "on" light indication will light when the pump circuit is energized.
Diesel Generator Status A watt meter (WM-103), an ammeter (AM-110) and a voltmeter (VM-105) are located in the control room on panel C01. The operation of the Diesel generator is also monitored via local and remote alarms. The remote alarms are located on the control room annunciator windows 34-EDG engine trouhic, 35-EDG start / control failures and 36-EDG overload.
If the EDG control switch is not in the automatic start position an alarm will sound in the control room. This is an additional way to monitor the status of the EDG, No continuous record of EDG status is available or deemed necessary.
OTHER DATA CAPABILITIES In addition to the above monitoring capabilities, other monitoring capabilities exist at Big Rock Point and are useful in reconstructing sequence of events during a transient, determination of the cause of unscheduled reactor shutdowns, in monitoring the operation of safety related equipment.
The following is a description of all the analog data recorders available.
The following parameters are continuously recorded on 10"-12" circular ink pen 24-hour charts. The recorder charts are powered form 480V Bus lA through I6C l
transformer IA and backup power is supplied automatically from the Emergency I
Bus 2B which is supplied by power from the emergency diesel generator on loss of normal station power supply to Bus 2B.
The circular charts are continuously tracking, supplying enough information to make reconstruction of a transient possible. The charts' divisions are at 15 minute intervals.
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Feedwater flow 2.
steam drum level 3.
Main steam flow
- 4. : Reactor pressure 5.
Steam conductivity 6.
Condensate tank level 7.
Demineralized water tank level 8.
Main condenser. level 9.
Feed pump suction pressure
- 10. Feed pump discharge pressure
- 11. Reactor recirculation pump flow
- 12. Condensate demineralizer flow
- 13. Condensate demineralizer Differential pressure
- 14. Condenser off-gas flow rate
- 15. Ditnolved oxygen in condensate
- 16. Fire pump discharge header pressure (7" circ chart. 7-day duration)
In addition to the circular charts the following continuous strip charts provide information useful in reconstructing the event.
1.
Reactor cleanup demineralizer diffe rential pressure 4" paper strip chart scaled at 0-50 psi DPR-7600.
2.
Reactor cleanup demineralizer flow.
4" paper scaled at 0-100 gpm FR-2101.
3.
Pipeway differential dewpoint MR-9621 - containment interior to steam drum /recire pump room 4" paper strip chart scaled 0-100'F TR-9623.
4 Enclosure clean and dirty sump level 4" strip chart 0-100% LR-3108, 5.
Fire system pressure King-Knight 7" circular chart scaled at 0-200 pai.
6.- Condensate system differential pressure recorder DpR-7601 Fisher-Porter 12" cire chart scaled 10-80 psi DPR-7601, 7.
Conductivity in condenser hotwell (2 points), cond tube leak (4 points) and clean-up demin (1 point) Industrial Instruments.
12" paper cire chart scaled 0-1.0 umho CR-6050.
8.
Condensate Demineralizer conductivity CR-6052 Leeds and Northrup speedomax g-type G.
12" strip chart scaled at 0-10 umhos.
3 pens CR-6052.
9.
Condensate demineralizer flow FR-2103 FR-2104 and FR-2105 Fisher-Porter 12" cire chart 3 pens scaled at 200-1400 gpm.
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- 11. Turbine pipeway dewpoint MR-9622 5" strip chart scaled to 0-100'F.
- 12. Make-up demineralizer inlet flow FR-2106 12" cire chart scaled to 0-100 l
gpm.
- 13. Make-up demineralizer outlet conductivity Leeds and Northrup Speedomax.
l 10" cire chart scaled 0-5 umhos.
- 14. Radwaste tank levels 5 pens on 3 separate recorders.
4" strip charts scaled at 0-100% LR-3101.LR-3102 LR-3103 LR-3106 LR-3107.
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- 15. Radwaste fivv rate to canal FRC-2050 4" paper strip chart scaled 0-100%.
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- 16. Radwaste domineraliter effluent conductivity 4" paper strip chart scaled i
0-Sumho CR-6051,
- 17. System electrical frequency (FQR-1107. FQR-1101). -Leeds and Norhtrup f
Speedomax recorder.
5" paper scaled 59-61 hertz and 50-70 hertz sespectively.
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- 19. Generator rotor temperature (TR-1052) General Electric 12" paper scaled 0-200'F.
- 20. Turbine shaft eccentricity General Electric 3" paper scaled at 0-15 mis.
- 21. Turbine admissions valves position and turbine speed TSR-7300 TSR-7301 General Electric 5" paper scaled at 1-100% valve position. 0-5000 rpm.-
l Admission valve position traced until main generator output oil breaker (116 OCB) opens, then it switches to turbine speed lY-8.
- 22. plant-electric power output (Net Mw).
-5" paper scaled at 0-100Mw.
- 23. Stack gas radiation (gGEM) - iod{ne/parituclates and noble gas (RR-8057).
4" paper scaled 10-10 and 10-10 counts per minute.
- 24. Stack gas radiation (RGEM) - high range noble gas recorder (RR-8058).
4" paper.
~ 25. Stack gas radiation (RGEM) - Intrinsic Germanium Detector Recorder (RR-8059). Three pen recorder located in Chemistry Lab.
-26. Air ejector to stack gas flow FR-2107.
- 27. off-gas slow recorder FR-2107 Bailey Meters 12" circular chart scaled 0-100%, 100% is 31cfm.
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- 28. Containment gap a monitor recorder RR-8055. Tractor-Westronics 4" paper scaled at 1-10 R/hr 1"/hr RR-8055.
- 29. Airborne particulate radiation Nuclear Measurement Corp. Gross monitor in the turbine building and gross monitor in containment 50-50,000 counts / min 5'_' scale.
- 30. Wind speed and direction at plant stack elevation 240' FR-2109 Esterline-Angus 0-540' and 0-100mps 6" paper, portable unit.
Since the above recorders are continuous, the sampling rate and the recording capability before end after the trip are apparent.
The following intermittent strip charts also provide information useful in reconstructing the event.
- 31. Incore neutron flux - General Electric 12" paper strip chart scaled 0-150% power. On demand-manual, 25 seconds after manual initiation.
2 sec/ point. RR-RJ13.
- 32. Reactor vessel temperature and steam drum temperature Tractor-Westronics Model DDR10, 12" paper strip chart scaled 0-750*F.
0.5sec/ point, 6"/hr TR-1A16.
- 33. Reactor recirculation pump temperatures (TR-1 A66).
20 pens at 10-second intervals for the seal, bearing and winding of each pump.
12" paper strip chart scaled 250'F.
1"/hr TR-1A66.
- 34. Selected dewpoint and air temperature for containment Foxboro 8" paper strip Chart scaled 0-300*F and 0-600'F.
II"/hr, 3sec/ point TR-9623,
- 35. Control rod drive temperature Cencral Electric, 32 points, 12" paper strip chart scaled 0-600'F, imin/ point TR-RD46,
- 36. Temperatures in shutdosm system, emergency condenser, feedwater heaters, exhaust steam, cond cire water, condensate and reactor clean-up Tractor-Westronics 12" paper strip chart scaled 0-400'F.
18 pens at 3 sec/ point, 4"/hr TR-1050,
- 37. Feedwater pump's temperature - pump bearing, motor hearing, motor windings, b
Honeywell 12" paper strip chart scaled 0-400*F 3 sec/ point 22 points TR-1054.
- 38. Station power Kw General Electric prints once per hour.
- 39. Generator gross Mw General Electric prints once per hour.
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- 40. Turbine expansion and vibration General Electric. Three-3" papers strip charts, 8 pens total, 4 sec/ point TR-7502.
- 41. Turbine generator lube oil temperature (TR-1051) Tractor-Westronics 12" paper scaled 0-200'F at 5 sec/ point 5" hour.
- 42. Generator stator temperature (TR-1053).
General Electric 12" paper strip chart scaled 0-200*F.
16 pens at 30 sec/ point 2"/hr.
- 43. Area radiation monitor and emergency condenser exhgust vent monitor (RR-8053) Tractor-Westronica 12" paper scaled 1-10 mR/hr.
19 pens used 3 sec/ point 4"/hr.
- 44. Process radiation Tractor-Westronics 12" paper 4"/hr 2 sec/pt RR-8054.
- 45. Containment exhaust air supply Nuclear Measurement Corp. iodine and gross particulate 3" paper 0-1.0 mamp.
- 46. Liquid poison valves and tank temperature Acco Bristol TR-1055 external temperatures for 7 valves and I tank temp 8" paper strip chart scaled at 0-25'F.
Important plant variables that require continuous monitoring for reconstruction are recorded on the plant circular charts. Additional information about transients can be obtained from the other sources of information delineated above.
Other Data Other sources of information available to help in reconstruction of the transient include; control room logbooks, shift supervisor logbooks, control room log sheets and personnel interviews.
Power Supplies All of the above mentioned recorders and monitors are powered by the essential service panels lY, 2Y and 3Y, except the containment gamma monitor which is powered from panel 6Y, the make-up demineralizer recorders and the RGEM system which are powered from the non-safety related Bus IE.
Essential Service distribution panels 1Y, 2Y and 3Y are fed from MCC-1A through the instrument and control transformer IA.
In the event of loss of off-site power, the emergency diesel generator supplies Bus 2B which is automatically tied to Bus lA by circuit breaker 52-1A2B thereby insuring that the essential service panels are always powered.
Panel 6Y is fed from Bus 2A which can be tied to the emergency Bus 2B during a loss of station power event.
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t The make-up demineraliter recorders are unimportant, therefore their power supply is of no consequence. The basic stack release can be obtained from the Air Ejector Of f Gas system (RR-RH06A and RR-RH06B).
DATA RETENTION All circular charts are saved and stored for the life of the plant in a document control vault.
Selective atrip charts are retained in a document control vault for the life of the plant. These strip charts are; stack gas recorders, liquid process monitor recorder, turbine building continuous air monitor recorder, and the containment continuous air monitor. Because of size and resolution, these documents are not microfilmed.
Control room logbooks and control room log sheets are filmed and maintained for the life of the plant, The Big Rock Point Technical Specification section 6.10 specifies that records t
and logs of facility operation covering time interval at each power level shall be retained for at least five years.
The Big Rock Point Staff has always concluded that adequate information about SCRAMS is available to make good determinations on cause and plant response to transients with the information available on charts, from logbooks and personnel interviews - post transient. The staff has always compiled files of all reactor trips for management and Plant Review Committee review in order to address causes and prevent recurrence, however, the more recent transients are much better documented.
These files are maintained at the plant site for future reference and review.
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