ML20126H530
| ML20126H530 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 12/30/1992 |
| From: | Ray H SOUTHERN CALIFORNIA EDISON CO. |
| To: | |
| Shared Package | |
| ML20126H528 | List: |
| References | |
| NUDOCS 9301050243 | |
| Download: ML20126H530 (12) | |
Text
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4 UtillED Sl ATES Of AMERICA W{LLAILREGUI ATORL(QMMISSION Application of SOUTiiERf1 CAllf 0 Rill A
)
EDISOff COMPANY, El AL. for a Class 103
)
Docket No. 50-361 License to Acquire, Possess, and Use
)
a Utilization facility as Part of
)
Amendment Application Unit fio. 2 of the San Onof re Nuclear
)
No. 129 Generating Station
)
SOUTilERN CAllf0RNIA EDISON COMPANY, [] M. pursuant to 10 CfR 50.90, hereby submit Amendment Application flo. 129.
This amendment application consists of Proposed Change Number (PCN) NPF-10 405 to facility Operating License No. NPf-10.
PCN f1Pf-10 405 is a request to revise San Onofre Unit 2 Technical Specification (15) 3/4.3.2, " Engineered Safety feature Actuation System Instrumentation," and TS 3/4.3.3, " Radiation Monitoring Instrumentation."
This proposed chenge would eliminate the Er.gineered Safety feature Actuation System TS requirements for the Control Room Isolation System particulate / iodine radiation monitoring channel.
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Subscribed on this day of N' fb 4' T
, 1992.
Respectfully submitted, SOUTHERN cal.lf0RNIA EDISON COMPANY Dy: c
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H rold B. Ray Senior Vice Pre i ent State of California
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before me, Ibd llb el onally O
l appearedYIl[b4M [> iii%, personally known to me to be the person whose name is subscribed to the within inst ument and acknowledged to me that he executed the same in his authorized capacity, and that by his signature on the instrument the person, or, the entity upon behalf of which the person acted, executed the inttrument.
W!1HESS my hand and official.eal.
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James A. Beoletto Attorney for Southern Calif,ornia Edison Company By:
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i UN11ED STATES Of AMERICA NUCLEAR REGUL410M COMMISS10N.
I Application of SOUTHERN CAllf0RNIA
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EDISON COMPANY, [I 6L. for a Class 103
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Docket No. 50-362 License to Acquire, Possess, and Use
)
a Utilization facility as Part of.
)
Amendment Application i
Unit No. 3 of the San Onofre Nuclear
)
No. 113 Generating Station
)
i SOUTHERN CAllf0RNIA EDISON COMPANY, il al. pursuant-to 10 CFR 50.90, hereby.
submit Amendment Application No. 113.
J This amendment application consists of Proposed Change Number (PCN) NPF-15-405 to facility Operating License No. NPF 15.
PCN NPF-10-405 is a request to revise t
San Onofre Unit 3 Technical Specification (TS) 3/4.3.2, " Engineered Safety feature Actuation System Instrumentation," and TS 3/4.3.3,_" Radiation Monitoring.
Instrumentation."
This proposed change would eliminate the Engineered Safety i
feature Actuation System TS requirements for the Control Room isolation System i
particulate / iodine radiation monitoring channel.
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00f'th b V Subscribed on this day of 1992.
Respectfully submitted, SOUTHERN Calif 0RNIA EDISON COMPANY Dyr j_
_w H rold B. Ray Senior'Vice Presit nt State of California County o Or o e On j ' ?O d'
k.lfMlk 11CllWg personally appeared MM[N(before me LL'1, personally known to me to be the person whose name is subscribedtothewitHninst/umentandacknoniedgedtomethatheexecutedthesameinhis authortred cupacity, and that by his signature on the instrument the person, or the entity upon behalf of which the person acted, executed the instrument.
W11 NESS my hand and official seal.
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James A. Beoletto Attorney for Southern California Edison Company y s c.
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L DESCRIPTION AND SAFETY ANALYSIS Of PROPOSED CHANGE NPF-10/15-405 Proposed Change NPF 10/15 405 (PCN-405) is a request to revise Technical Specification (TS) 3/4.3.2, " Engineered Safety feature Actuation System Instrumentation," (ESFAS) and TS 3/4.3.3, " Radiation Monitoring Instrumentation," for SONGS Units 2 and 3.
PCN 405 would eliminate the ESfAS technical specification requirements for the Control Room isolation System (CRIS) particulate / iodine radiation monitoring channel.
Existinn Specification:
Unit 2: See Attachment "A" Unit 3: See Attachment "B" P_toposed Splcifica11pm Unit 2: See Attachment "C" Unit 3: See Attachment "0" SCC proposes to eliminate TS requirements and ESfAS circuitry for the CRIS particulate / iodine ESfAS channel.
This proposed change would avoid future spurious CRIS actuations and eliminate the need to perform unnecessary maintenance, TS surveillance, and administrative controls.
BACKGROUND Control Room 1sp]ation_ Snic!L The Technical Specification 3/4.3.2 Limiting Condition for Operation (LCO) requires a minimum of one out of two CRIS airborne particulate / iodine channels OPERABLE at all times.
The same LCO applies to the airborne gaseous radiation monitoring (radmonitor) channels. Whenever both gaseous channels or both particulate / iodine radmonitor channels are not OPERABLE, the ACTION Statement requires that within one hour the emergency cleanup system must be placed in the emergency mode of operation. Technical-Specification 3/4.3.3 provides the LC0 requirements for radmonitor instrument measurement ranges. Together these two TSs comprise the CRIS radmonitors LCO requirements. TS surveillances are required to be performed shiftly, monthly, and at refueling intervals.
The function of the Control Room Airborne (CRA) Radiation Monitoring Instrumentetion is to detect airborne radioactivity entering the control rcom normal ventilation supply and initiate a CRIS signal.
There are two CRA monitors and two separate and redundant trains of CRIS instrumentation.
Each train of CRIS instrumentation has one CRA monitor. A CRIS signal from either train will shut the associated train heating ventilation and air conditioning (HVAC) isolation dampers and start the associated train emergency HVAC recirculation unit. This is known as the emergency mode of operation, in the emergency mode of operation, the control room operators would manually align the CRA radmonitors to the HVAC emergency recirculation flow path.
The emergency I
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mode of operation ensures control room habitability would be maintained in accordance with 10 CfR 50 Appendix A. General Design Criterion (GDC) 19.
Each train of CRA monitors has two channels, a gaseous channel and a combined particulate / iodine channel.
Either of the two channels will actuate their respective train. A CRIS actuation setpoint of two times background was chosen to avoid spurious actuations yet provide protection for the control room as soon as activity reaches abnormal levels.
Each CRIS airborne radmonitor draws a sample from the HVAC sup)1y duct and directs the sample to a fixed paper / charcoal filter media whic1 collects i
particulate and iodine. A scintillation detector senses the radioactivity from the radioisotopes accumulated by the filter media and generates an output signal.
The iodine / particulate channels only indicate integrated activity with respect to time, for low levels of activity, the time required for the filter media to collect sufficient radioisotopes to trigger a CRIS iodine / particulate channel is relatively long compared to the CRIS gaseous channels.
By a similar process, radioisotopes are sensed by the scintillation detector _ of the CRIS gaseous channels.
However, unlike the particulate / iodine channel, the gaseous channels do not use a filter media.
The gaseous channels indicate instantaneous activity.
The gaseous channels respond quicker than the particulate / iodine channel because filter accumulation time is not required.
The design of the CRls system assumed that minimal maintenance would be required for the radmonitors. Our experience, however, has shown that considerabic effort has been required to maintain the particulate / iodine channels.
The plant has experienced numerous spurious CRis actuations attributed to the need to frequently change the filter media or service the skids.
Each actuation of CRIS perturbs normal control room operation.
Eliminating the CRIS particulate / iodine channel TS would relieve the plant of a significant amount of unnecessary effort.
The CRIS radmonitor particulate / iodine-channel setpoint and response times have been evaluated in comparison with that of the-noble gas channels.
The results indicate the response of the noble gas channels would be sufficient to provide the required ESFAS function.
There are no postulated accident scenarios that could introduce radioactive particulate er iodine into the control room HVAC without also introducing detectable quantities of radioactive noble gas. The noble gas channels have the sensitivity to initiate the CRIS signal before the particulate / iodine channels.
Should a design basis event occur, the response time of the noble gas channels would determine the time required to initiate the CRIS signal.
Since this PCN would not alter the response time of the noble gas channels, the existing safety analysis would not be_ impacted.
The particulate / iodine channel ESFAS function could be eliminated without any change in the plants ability to perform the CRIS function.
The proposed change would be consistent with the guidance provided in SRP 6.4,
" Control Room Habitability Systems." To minimize the hazard to an individual
-inside the control room, this SRP requires that for any postulated design basis accident, the dose should not exceed GDC 19 guidelines.
SRP 6.4 does not
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L require the use of particulate or iodine radmonitors to achieve compliance witii GDC 19.
SCE has reviewed the design basis for the CRIS system and has determined that TS 3/4.3.2 requirements for the radiation monitoring particulate / iodine channels are unnecessary.
This determination was based on the ability of'the existing I
noble gas radiation monitoring channels to meet all of the design basis criteria and adequately perform the required ESFAS functions of the CRIS system.
PCN 405 would revise TS 3/4.3.2 and TS 3/4.3.3 to eliminate the CRIS particulate / iodine channel requirements.
l DESCRIPTION
[xistina_ Specification Control Room Airborne Monitors (2/3 RT 7824-1 and 2/3 RT-7825-2) are part of the CRIS system.
The ESTAS OPERABillTY and Surveillance Requirements for CRIS instrumentation are identified in Technical Specification 3/4.3.2," Engineered Safety feature Actuation System Instrumentation."
OPERABILITY of CRIS instrumentation ensures that 1) the associated ESFAS action will be initiated when the parameter monitored by each channel reaches its setpoint; 2) the specified coincidence logic is maintained; 3) sufficient redundancy is maintained to permit a channel to be out of service for testing or maintenance; and 4) sufficient system functional capability is available from diverse parameters, t
OPERABILITY of the CRIS system is required to provide the overall reliability, redundancy and diversity assumed available in the facility design.to mitigate the radiological consequences for control room personnel-following an accident.
The integrated operation of the ESFAS CRIS system is consistent with the assumptions used in the' accident analyses.
The Surveillance Requirements specified for the CRIS system ensure that the overall system functional capability is maintained comparable to the original design standards, t
TS 3/4.3.3, " Radiation Monitoring Instrumentation," also provides CRIS-instrumentation OPERABILITY and Surveillance Requirements.
OPERABILITY of the radiation monitoring alarm channels ensures that 1) the radiation levels are continually measured in the areas served by the. individual channels; and 2) the alarm or automatic action is initiated when the radiation level trip setpoint is exceeded.
Proposed Specification SCE-proposes to eliminate TS requirements and ESFAS circuitry for CRIS particulate / lodine ESFAS channels.
This proposed change would avoid future
- spurious CRIS actuations and eliminate the need to perform unnecessary maintenance, TS surveillance, and administrative controls.
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o PCN 405 would eliminate CRIS requirements in 15 Table 3.3-3. Table 3.3-4, and Table 4.3-2, for radmonitors 2/3 RT-78241 and 2/3 RT-7825 2 particulate / iodine channels.
Radmonitors 2/3 RT-7824-1 and 2/3 RT-7825-2 have two TS required channels; a gaseous channel and a combined particulate /todine channel.
PCN-405 would require the CRIS signal be initiated by the redundant gaseous channels only. This proposed change is consistent with the guidance provided in SRP 6.4,
" Control Room Habitability Systems." To min 1970 the hanrd to an individual inside the control room, this SRP requires that for any postulated design basis accident, the dose should not exceed GDC 19 guidelines.
The SRP does not require the use of particulate or iodine radmonitors to achieve :ompliance with CDC 19.
PCN 405 would eliminate cpecifications for radmonitors 2/3 RT-7824 1 and 2/3 RT-7825-2 particulate channels listed in TS Table 3.3-6 and Table 4.3 3.
1hese channels would be eliminated frorr the Radiation Monitoring Instrumentation TS hince they are not required to meet the recommendations of Regulatory Guide 1.97, " Instrumentation for Light-Water cooled Nuclear Power Plants to Assess Plant and Environs Conditions During and following an Accident," and NUREG-0737, " Clarification of IMI Action Plan Requirements," which contain the Bases-fer the Radiation-Monitoring Instrumentation TSs.-
Provided below are the requested changes to the Units 2 and 3 TSs, followed by the explanation for each change.
REQUESTED CHANGES 1he requested changes for each technical specification are:
TS Table 3.3-3."Encineered Safety feature A.pluation Sv1Lem Instrumentation"
-Delete functional Unit 9.c.i, " Particulate / Iodine."
Insert the word " Deleted".
-TS Table 3.3 4."Enci9eered Safety feature Actuation System instrumentation Tria Values"
- Delete functional Unit 9.c.1, " Particulate / lodine,"
Insert the word " Deleted".
TS Table 4.3-2 "Enaineered Safety Feat _ure Actuation System Instrumentation Surveillance Reauiremeatji Delete Functional Unit 9.c.i, " Particulate / lodine."
insert the word " Deleted".,
4 TS Table 3.3-6. " Radiation Monitorina Instrumentation" Delete Instrument 2.c.i, " Particulate."
insert the word " Deleted".
TS Table 4.3-3. " Radiation Monitsrina Instrumentation Surveillance Requirements" Delete Instrument 2.c.1, " Particulate."
Insert the word " Deleted".
EXPLANATION OF REQUESTED CHANGES This section provides the explanation of each change request item.
TS Table 13-3."Enotneered Safety Feature Actuation System Instrumentation" SCE requests deletion of Table 3.3-3 CRIS particulate / iodine channel. Our review of SRP 6.4 requirements for the CRIS system determined that-the-particulate / iodine radiation monitoring channel is not required.
The existing gaseous radiation monitoring channels adequately perform the required CRIS actuation functions.
Since the particulate / iodine channel is not required, we request to delete the particulate / iodine channel.
TS Table 3.3-4."Encineered Safety feature Actuation System Instrumentation Trio values" SCE requests deletion of Table 3.3 4 CRIS particulate / iodine channel. Our review of SRP 6.4 requirements for the Control Room Isolation System determined that the particulate and iodine radiation monitoring channel is not required.
Since the particulate / iodine channel is not required and since the existing gaseous radiation monitoring channels adequately perform the required CRIS actuation functions, we request to delete the particulate / iodine channel trip values.
TS Table 4.3-2."Enaineered Safety feature Actuation System Instrumentation Surveillance Reouirements" SCE requests deletion of Table 4.3 2 CRIS particulate / iodine channel. Our review of SRP 6.4 requirements for the Control Room Isolation System determined that the particulate / iodine radiation monitoring channel is not required.
SRs for the existing gaseous radiation monitoring channels will-be retained to assure OPERABillTY of the required CRIS actuation instrumentation. I
TS Table 3.3-6 Radiation Monitoring _ Instrumentation SCE requests deletion of Table 3.3 6 CRIS particulate channel.
Our review of i
the plant safety analysis and SCP 6.4 requirements for the Control Room isolation System determined that the particulate radiation monitoring channel is not required.
Since there are no regulatory requirements for retaining this channel, and since the existing gaseous radiation monitoring channels adequately perform the CRIS actuation function, we request to delete the particulate channel. The existing gaseous radiation monitoring channels will be retained to ensure the required CRIS actuation functions will be performed.
TS Table 4.3-3. " Radiation Monitor.inq_lnstrumentition Surveillance Reouirements" SCE reques;ts deletion of Table 4.3.3 CRIS particulate channel. Our review of the plant safety analysis and SRP 6.4 requirements for the Control Room Isolation System determined that the particulate radiation monitoring channel is not required.
Since this PCN would delete the particulate channel, surveillance for this channel will no longer be requir'd.
SRs for the existing gaseous radiation monitoring channels will be retained to assure OPERABILITY of the required CRIS instrumentation.
SAFETY ANALYSIS:
The proposed change described above shall be deemed to involve a significant hazards consideration if there is a positive finding in any 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 change would eliminate the-ESFAS technical specification-requirements and ESFAS circuitry of the CRIS particulato/ iodine _ radmonitor channel.
The function of the particulate / iodine channel is to detect airborne radioactivity entering the control-room normal ventilation' supply and initiate a CRIS signal.
The CRIS signal realigns the ventilation system to a configuration that -is capable of maintaining a suitable control room environment following a Design Basis Accident.
Since the CRIS particulate / iodine channels are only used following an accident, the probability of occurrence of an accident previously evaluated would not be affected by the proposed change.
CRIS instrumentation is credited in the UFSAR for-two design basis events:
a steam generator-tube rupture and a FHA _inside containment.
Eliminating-the particulate / lodine channel would not alter the ESFAS function of the CRIS signal.
The response time of the CRIS particulate / iodine channel has been evaluated in comparison with the CRis gaseous channels.
The gaseous 6-
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k, channels would respond to initiate a CRIS signal faster than the particulate / iodine channels.
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 change would eliminate ESFAS technical specification requirements and ESFAS circuitry of C 51S instrumentation used solely for the purpose of protecting the control room during a design basis accident.
Eliminating the particulate / iodine channel would not. alter the ESFAS function of the CRIS system. With the exception of eliminating these two channels, the proposed change would not alter the design of the interface between CRIS instrumentation and existing plant equipment.
CRIS functions would continue to be performed by the redundant gaseous channels of the airborne radmonitors. Operation of the facility in accordance with this noposed change would not create the possibility of a new or different (ind of accident from any previously evaluated.
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 change would eliminate ESFAS technical specification requirements and ESFAS circuitry of the CRIS particulate / iodine channel.
During all credible accidents which require CRIS actuation, the gaseous radmonitor channels would initiate-the. required safety function.
Since the proposed change would not alter the _ response of the gaseous channels, operation of the facility in accordance with the proposed change would not involve a significant reduction in a margin.of safety.
CRIS instrumentation is credited in the UFSAR for two design basis events:
a steam generator tube rupture and'a FHA inside containment.
Eliminating the particulate / iodine channels would not alter the ESFAS function of the CRIS signal. The response time of the particulate / iodine channel has been evaluated in comparison with the CRIS gaseous channel. The gaseous channels would respond to initiate a CRIS signal faster than the particulate / iodine channels.
Since for both design basis events, the response of the redandant gaseous channels would initiate a CRIS signal faster than would the particulate / iodine channel, operation of the facility in accordance with this proposed change would net involve a significant reduction in a margin of-safety.
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4 SAFETY AND SIGNIFICANT HA7ARDS CONSIDERATION DETERMINATION Based on the preceding Safety Analysis, it is concluded that:
(1) the proposed change does not constitute a significant hazards consideration as defined by 10~
CFR 50.92; (2) there is a reasonable assurance that the health and safety of the public will not be endangered by the-proposed change; and (3) this action will not result in a condition which significantly alters the impact of the station-on the environment as described in the NRC Final Environmental Statement.
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