ML20126F816

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Application for Amends to Licenses NPF-10 & NPF-15, Respectively,Consisting of Proposed Change Numbers 127 & 111,revising TS 3.3.3.1, Radiation Monitoring, to Increase Required Number of Plant Vent Stack Wide Range Gas Monitors
ML20126F816
Person / Time
Site: San Onofre  Southern California Edison icon.png
Issue date: 12/30/1992
From: Ray H
SOUTHERN CALIFORNIA EDISON CO.
To:
Shared Package
ML20126F806 List:
References
NUDOCS 9212310149
Download: ML20126F816 (10)
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Text

Ilf f0RL 1110 UNIIED STAILS NUCLEAR REGUI A10RY COMMISSION Application of 50VillERN CAlll0RNIA LDISON COMPANY, ET AL, for a Class 103 License to DOCKET NO. 50 362 Acquire, Possess, and Use a Utilitation facility as Part of Unit No. 3 of the Amendment Applu:ation No. 111 San Onofre Nuclear Generating Station S001tlERN CAllf0RNIA [DISON COMPANY El AL., pursuant to 10 CIR 50.90, hereby submit Amendment Application No. 111.

This amendment consists of Proposed Change Number (PCN) NPf 15 416 to f actitty Operating License No. NPf 15. PCN NPf 416 is a request to revise San Onofro Unit 3 lechnical Specification (15) 3.3.3.1, "RADIA110N MON 110 RING INSTRUMENIA110N." 1his amendment request increases the number of plant vont stack wide range noble gas radiation monitors from 1 to 2 when either Unit 2 or 3 is in Hodo 1, 2 or 3. When either Unit 2 or 3 is in Mode 4 and the other unit is in Mode 4, 5, or 6, either the plant vent stack monitor (2/3RT-7808) or both wide range gas monitors (2RT-7865 1 and 3RT 7865 1) will be required.

Editorial clarifications are also made.

9212310149 921230 fDR ADOCK 0D000361 PDR

i .' ,

Subscribed on this 8C I# day of J)ECENd68 ,1992.

Respectfully submitted.

SOUTHERN CAllFORNIA EDISON COMPANY

. By: HI NdB. Ray

. 1 >

4 Senior Vice Pres it l

State of California County of Orange On /.?l90/9 L before tne, 2?AddA/A A, Af e c AKTH fN -

personally appeared MA/ft.b B, / 4 / , personally known to me to be.

the person whose name is subscribed to the within instrument 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 l the person acted, executed the instrument.

WITNESS my hand and official seal. omCLAt stat '

BARBARA A MC CARTHY Notory 1%5c Collfornlo l ORANGE COUNTY My Coenmiselon Empires Much 31,1995 Signature , b / W o O . ( L y

i James A. Beoletto Attorney for Southern-California Edison Company

m. .,

By:-

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Jam A. Beoletto

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BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION ,

i 1

Application of SOUTHERN CAllFORNIA EDISON t COMPANY, ET l.L. for a Class 103 License to DOCKET NO. 50-361 .

, Acquire, Possess, and Use a Utilization i Facility as Part of Unit No. 2 of the Amendment Application No. 127 San Onofre Nuclear Generating Station l

SOUTHERN CAllf0RNIA EDISON COMPANY ET AL., pursuant to 10 CFR 50.90, hereby submit Amendment Application No. 127. ,

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IhisamendmentapplicationconsistsofProposedChangeNumber(PCN)NPF-10-416 to facility Operating License No. NPF-10. PCN NPF-416 is a request to revise  ;

San Onofre Unit 2-Technical Specification (TS) 3.3.3.1, " RADIATION MONITORING L

INSTRUMENTATION." This-amendment request increases the-number-of plant vent stack wide range noble gas radiation monitors from 1 to-2 when either Unit 2 or -

3 is in Mode 1, 2, or 3. When either Unit 2 or 3:is in Mode 4 and the other +

unit is in Mode-4, 5, or 6, either the plant vent stack monitor (2/3RT-7808) or bothwiderangegasmonitors(2RT-7865-1and:3RT-7865-1)willberequired. ,

Editorial clarifications are also made. ,

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. I Subscribed on this J o M day of 3EcEMdE A ,1992.

Respectfully submitted,

't SOUTHERN CALIFORNIA EDISON COMnANY I

Dy: , __

Ha old B. Ray Senior Vice Presid i

State of California

County of orange before me, SAddAAA A. flC CAR. THY ?fY! "

on /9l30l9 3.

personally appeared MA/N b R /A V . personally known to me to be the per$on whose name is subscribed to the within instrument and acknowledged to me that he executed the same in his authcrized capacity, and that by his signature on the instrument the person, or the entity upon behalf of which the person acted, executed the instrument, OFFICIAL SEAL _

WITNESS my hand and official seal. BARBARA A MC CARTHY g Notory Putsc Confornlo ORANGE COUNTY W commWon EWm Much 31,1996

! signature , M eta o d M'My James A. Beoletto Attorney for Southern California Edison Company N

By: * ~

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l s A. Beoletto '

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ENCLOSURE i l

i DESCRIPTION AND SAFETY ANALYSIS  !

i 0FPROPOSEDCHANGENPF10/15416 i

1 This is a recuest to revise Technical Specification (TS) 3.3.3.1, " RADIATION MONITORING ihSTRUMENTATION" for the San Onofre Nuclear Generating Station, Units 2 and 3. The proposed change will require both Unit 2 and 3 plant vent

stack wide range noble gas radiation monitors (2RT-7865 1 and 3RT 7865 1) to be operable when either Unit 2 or 3 is in Mode 1, 2, or-3. When either Unit 2 ,

or 3 is in Mode 4 and the other unit is in Mode 4, 5, or 6, either the plant 1 vent stack normal range monitor (2/3RT 7808) or both 2RT 7865-1 and 3RT 78651 '

will be ,*equired.

l' ElllD NG.. TECHNICAL SPECIFJ. CATION (S1  ;

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J Attachment A - Unit 2 TS  :

Attachment 8 Unit 3 TS r

P l PROPOSED TECHNICAL SPECIFICATION (S).

Attachment C - Unit 2 TS

  • Attachment 0 Unit 3 TS
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l D110E12I10B Technical Specification (TS) 3.3.3.1 " RADIATION MONITORING INSTRUMENTATION,"

, providestheLimitingConditionsforOperation(LCOs)relatedtoprocess, i area, and noble gas radiation monitoring instrumentation. Table 3.3 6 presents the ap)11 cable modes of operation, specific LCO requirements, and

ACTIONS for eac1 radiation monitoring instrument channel. Table 3.3 6, item

, 3.a specifies that either 2RT 7865 1 or 3RT 7865 1 wide range noble gas radiation monitor may be used for monitoring both Unit 2 and Unit 3-Plant Vent  ;

Stack (PVS) effluent pathways. This proposed change will require both Unit 2.

l and Unit 3 PVS wide range noble gas monitors, 2RT-7865-1 and 3RT 78651, to be operable when either Unit 2 or 3 is in ,iode-1, 2. or 3. When either Unit 2 or 3 is in Mode 4 and the other unit is in Mode 4, 5, or 6 either the plant vent stack normal range monitor (2/3RT-7808) or both 2RT 7865-l' and 3RT-78651 will- /

be required. .

The following specific changes to Unit 2 and Unit 3 TSs 3.3.3.1, " RADIATION-

MONITORING INSTRUMENTATION" are requested
.
1) Table 3.3 6, RADIATION MONITORING INSTRUMENTATION:
a. Replace item 3.a Plant Vent Stack-Wide Range-monitors."(2RT-7865 1 or 3RT-7865 1)" with "(20T ?M H .and 3RT-7865 1)."
b. Replace item 3.a Plant Vent Stack Noeal Range monitors

"(2RT-7865 1, 3RT-7865 1 or 2/3RT 18UB)" for Unit 2 TSs and l "(2/3RT-7808 or 2RT-7865 1 or 3RT-7865-1)" for Unit 3 TSs with "(2/3RT-7808, or both'2RT-7865 l_and 3RT-7865 1)," for both Unit 2 and 3 TSs.

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. .,. l 4 c. Change item 3.a Plant Vent Stack Wide Range monitor HINIMUM l CHANNELS OPERABLE by replacin "1" with "2.  :

Add the following footnote (2 for item 3.a. Plant Vent 9~ '

d.

Stack, Wide Range in the APPL CABLE MODES column "When .
either Unit 2 or 3 is operating in Mode 1, 2 or 3."  !
e. for item 3.a. Plant Vent Add Stack, the following Normal Rangefootnote (3)licable Modes Column:*When in the App i either Unit 2 or 3 is operating in Mode 4."
f. Add the following footnote (4) for item 3.a. Plant Vent  ;

Stack, Normal Range monitors in the MINIMUM CHANNELS OPERABLE column "When using 2/3RT-7808 one channel is required, or when using both 2RT-78651 and 3RT-78651 two ,

channels are required.

! g. Change the format of items 3.a. 3.b. and associated

! footnotes so that the Unit 2 and 3 TSs are consistent.

2) Table 4.3 3, RADIATION MONITORING INSTRUMENTATION SURVE!LLANCE  ;

REQVIREMENTS:

)

i Add the following footnote (3) for item 3.a. Noble Gas Monitors, '

, Plant Vent Stack in the MODES FOR WHICH SURVEILLANCE IS REQUIRED j column "When either Unit 2 or 3 is operatin'.ein Mode 1, 2, 3, or t'

, 4."

RASIS FOR_AND ACCEPTABILITY OF THE REQ K il .

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On January 11, 1985, TS Amendment Nos. 31 and 20 were issued approving

! Proposed Change Number (PCN) 100. PCN 100 reduced the required number of PVS wide range noble gas radiation monitors from 2 to- 1. This proposed change

will restore the-previous PVS wide range noble gas radiation monitoring requirements and satisfy the acceptance criteria of the Standard Review Plan (SRP)11.5,"PROCESSANDEFFLUENTRADIOLOGICALMONITORINGINSTRUMENTATIONAND
SAMPLING SYSTEMS." -

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The basis for NRC approval of PCN 100, as stated in the NRC Safety Evaluation i

Report, was the assumption of uniform mixing in the common Continuous Exhaust Air Plenum (CEAP). However, testing has verified that mixing in the CEAP is [

dependent on a number of variables and may not always be uniform.- Thus,

. contrary to the original assumption of uniform mixing in the CEAP, the waste gas effluent from each PVS may contain t. Variable fraction of the total PVS radioactivity released.

This proposed change will' increase the required number of PVS wide range radioactive noble gas monitors from 1 to-2 when either Unit 2 or 3 is in Mode 1, 2 or-3. In Mode 4, both wide range radiation monitors, 2RT 7865 1 and' ,

3RT 78651, will be required when the normal range radiation monitor 2/3RT-7808 is not operable. The increased monitoring requirements will provide one qualified radioactive noble gas monitor for each PVS waste gas effluent pathway.in Modes 1 4 without taking_ credit for mixing in_the CEAP.

According to Regulatory Guide 1.97, Rev. 2 and NUREG 0737, section !!.F.1 .

only one Wide Rt.nge. Gas Monitor!(WRGM) is. required for each gaseous release path per unit. The use of two WRGMs- for monitoring three accident effluent release paths (Unit 2 and 3 plant yent stacks and either the Unit 2 or Unit 3

3 Containment Purgo Stack (CPS)) was accepted as justified in UFSAR Section 11.5 and NRC Question and Response 321.12. The justification was based on containment purging being a deliberate planned activity and that uniform mixing occurred in the common CEAP with an equal distribution of effluent through the Unit 2 and 3 PVSs. The CPS has isolation valves and is considered a controlled effluent release path with TS operability requirements for the containment and purge isolation systems. However, because the assumption of uniform mixing in the CEAP may not always be valid, both 2RT 7865 1 and 3RT-7865 1 are required to ensure that continuous wide range radioactive noble gas monitoring is available for both the Unit 2 and 3 PVS post accident effluent pathways when either Unit 2 or Unit 3 is operating in Mode 1, 2, or 3.

SYSTEM OVE,PU Df there is one PvS and one CPS for each Unit. Each of these four separate gaseous effluent release pathways has a different source of waste gas and different operational requirements.

Each PVS is designated for either Unit 2 or Unit 3, however, both originate from a common CEAP. Waste gases generated from various sources at both Units 2 and 3 are directed to a common CEAP for release to the atmosphere via the two PVSs. The following sources of waste gas are discharged to the CEAP:

  • Ventilation exhaust from the Unit 2 Fuel Handling Buildings, Safety Equi) ment Buildings, and Penetration areas
  • Ventilation ex1aust from the Unit 3 fuel Handling Buildings, Safety Equipment Buildings, and Penetration areas
  • Ventilation exhaust from the common radwaste area, control area hoods, health physics lab control area, and turbine lab control area
  • Vent gas collection header for various potentially radioactive liquid tanks
  • Waste gas decay tank discharge header Exhaust air is normally drawn from the CEAP by two exhaust fans which ,

discharge to the atmosphere through the two PVSs. A third exhaust fan is available as an installed spare.

Each PVS is considered an independent effluent release pathway even though both the Unit 2 and 3 PVSs originate from a common CEAP. Different amounts of radioactive effluent may be discharged through each PVS because the physical design of the CEAP can not assure complete mixing under all conditions. The quantitative distribution of radioactivity between Unit 2 and 3 PVSs is dependent on the selection of CEAP exhaust fans and the current sources of waste gas.

The CPSs provide separate effluent pathways for each of the Unit 2 and Unit 3 containment building normal purge and mini-purge systems. One CPS is provided for Unit 2 and one for Unit 3. In contrast with the PVS, the CPS for each unit is completely independent with no common connection:;. The mini-purge system purges containment to reduce containment pressure and allow operator-access during power operation. The normal purge system purges containment following a plant shutdown for maintenance activities.

4 The PVS radioactive noble gas offluents are monitored using 2R1-7865 1, 3RT-7865 1, and 2/3RT 7808. The WRGMs 2RT-7865 1 and 3RT 7865 1, are the only radiation monitors with the extended range required by NUREG 0737, ll.f.1 attachment I and Regulatory Guide 1.97 Rev. 2. During normal operations radiation monitor 2/3RT-7808 monitors the CEAP and both 2RT 7865 1 and 3RT-7865-1, are required to monitor their respective PVS. However, the WRGH sample lines can be aligned to either the PVS or the CPS for each of their res)ective units. This allows the CPSs to be monitored using either the air)orne radioactive monitors (2RT-7828 and 3RT 7828) during normal plant operation, or the WRGMs (2RT-7865-1 and 3RT 7865-1) during an accident.

BACKGR_RlJM Wide range noble gas radiation monitors 2RT-7865-1 and 3RT 7865-1 were installed to provide the pnst accident PVS and CPS noble gas monitoring specified in NUREG 0737, " Clarification of TMl Action Plan Requirements" (November 1980), in response to NUREG 0660, "NRC Action Plan Developed as a Result of the TMI 2 Accident" (February 1981), justification was provided for installing one wide range monitor at each unit, which can be aligned to either the PVS or the CPS. This configuration was accepted by the NRC in NUREG 0712, Supplement #1 (February 1981), and the original 1Ss required both plant vent stack monitors to be operable.

On April 2, 1984 Amendment Application Nos. 25 and 11 for San Onofre Units 2 and 3 respectively, submitted PCN 100 which requested, in part, that the number of required PVS wide range noble gas monitors be reduced from 2 to 1.

Justification for this request included the assumption of uniform mixing in the CEAP and that post accident purging was a deliberate planned activity. On these bases Amendment Nos. 31 and 20 approved PCN 100 on January 11, 1985.

InSeptember1984,ScienceApplicationsInternationalCorporation(SAIC) evaluated the effects of iodine plate out in gaseous radioactive effluent monitor sample lines at San Onofre Units 2 and 3. As part of this ) late out investigation an evaluation of mixing in the CLAP was performed. T1e SAIC report concluded that the distribution of effluent radioactivity between the Unit 2 and 3 PVSs is dependent upon the current sources of gaseous waste '

effluent and the particular exhaust fans in operation. SAIC reported that radioactive discharges from the radwaste building ventilation will be discharged through both PVSs relatively uniformly for most reactor operations and exhaust fan configurations; most of the radioactivo discharges from each fuel Handling ventilation system will be discharged predominantly from their respective stacks; and the radioactive discharges into the other CEAP inlets will likely exit, primarily through the Unit 3 stack.

The crimary purpose of the SAIC study was to evaluate the effects of plateout in the radioactive effluent monitor sam)le lines and not to determine mixing in the CEAP. Based on the results of tais study, a followup evaluation was initiated to investigate the ramifications of the results of this study.

However, the need to expeditiously perform this evaluation due to the possibility of a non conservative TS was not recognized. When the evaluation task was reviewed earlier this year, administrative controls were implemented to require' two operable wide range noble gas monitors and preparation of this proposed change to the TSs was initiated.

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! DISCUSSION- )

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! The purpose of this proposed change is to correct the TSs to reflect the-

! potential for non uniform mixing in the CEAP. Because each PVS is'a separate  :

effiuent release pathway, separate wide range noble gas radiation monitors are-  ;

i required to satisfy the acceptance criteria of SRP 11.5. In addition to the  !

! PVS wide range monitoring function, 2RT-7865 1 and 3RT 7865-1 are also '1

. credited for wide range monitoring of the CPS effluent release pathway.

! Purging of containment atmosphere is a deliberate planned activity to reduce

containment pressure for operations and maintenance activities. During normal l plant operations the radioactive efflucat from containment atmosphere pu ging j through the CPS is monitored using the. normal range radiation monitor, 2 3)RT-i 7828. If either 2RT 7865 1 or 3RT 7865 1.is used to monitor the CPS whi e
operating in Mode 1, 2, or 3, the ' requirements of TS 3.3.3.1 Action 19 must' l 3 be satisfied,-because one monitor would not be aligned to the PVS as required -

!' by these TSs. In addition,-before the WRGH sample line is realigned from the PVS to the CPS, chemistry personnel will determine the PVS effluent ratio' 1 according to Chemistry-procedure 50123 111-5.22.23 " Units 2/3 Determining a r i Source Term for Offsite Dose Calculations in an Accident Situation," to c conservatively approximate the amount of-radioactive effluent released from the unmonitored PVS while the WRGM is aligned to the CPS.-

il i TS requirements for containment and purge isolation systems ensure that the  :

i CPS would not be an uncontrolled radioactive effluent release pathway in the

! event that a design basis accident occurs while purging containment.

! Containment purging is automatically-terminated in response to Engineered l' 2 Safety Feature Actuation System signals for Containment Purge Isolation, Safety Injection Actuation, Containment isolation Actuation, or with high

radiation levels detected by 2(3)RT-7828 (or 2(3)RT 7865 1 when aligned), or
  • radiation monitor failure. Furthermore, containment purging is.not credited in the Emergency Operating Instructions for post accident containment pressure and temperature control. . llowever, even if ) urging of containment is desired l after an accident, the associated WRGM'can 30 aligned to_the. CPS for E monitoring the radioactive effluent release.

This proposed change will require the existing ACTION 19 of- TS 3.3.3.l to be _

initiated when eitler Unit 2 or 3 is in Mode 1, 2, or 3, and either 2RT 7865-1.

or 3RT 7865 1 is not monitoring the PVS. When either Unit 2 or 3 is in Mode 4-and the other unit is in Mode 4, 5. or 6, ACTION 19 is invoked _when the normal plant vent stack monitor (2/3RT 7808) and either 2PT-7865-1 or 3RT-7865 1 is not operable. The existing requirements of ACTION 19 allow 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to restore the inoperable-PVS noble gas radiation' monitor channels to OPERABLE or-initiate a preplanned alternate method .of monitoring the PVS with submittal of a special' report, SAFETY ANAL.YS15 .

- The proposed change described above shall be deemed to involve a significant hazards considerationLif there is a positive finding in any of the following; areas:

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1. Will operation of the facility in accordance with this proposed change  !

involve a significant increast in the probability or consequences of an  ;

accident previously evaluated? _i Response: No.

]

This proposed change increases the number of wide range noble gas plant vent stack radiation monitors from one to two. The proposed TS will i require that whenever Unit 2 or Unit 3 is in Mode 1, 2. or 3, both plant e vent stack effluent pathways will be continuously monitored. In Mode 4  :

either the normal plant vent stack monitor (2/3RT-7808) or both 2RT-7865 1 and 3RT-7865-1 will be required. This proposed change does not reduce the requirements for any radiation monitor credited in the UFSAR for mitigation of the consequences of any previously evaluated accident. -

Therefore, this proposed change will not increase the probability or consequences of an accident previously evaluated.  !

Will operation of the facility in accordance with this

2. )roposed amendment create the possibility of a new or different dnd of accident
from any accident previously evaluated?

1-l Response: "No"

This proposed change increases radiation monitoring requirement $'using

, existing qualified equi) ment. This proposed change neither adds new i equipment nor changes t1e configuration or operation of the plant.

Therefore, no new or different kind of accident'is created from any previously evaluated.

i

. 3. . Will operation of the facility in accordance with this proposed >

l amendment involve a significant reduction in a margin of safety?

Response: "No" i

This pro)osed change increases the operability requirements'for wide  ;

range noale gas plant vent stack radiation monitors. This proposed change is limited to the requirements of PVS radiation monitoring with 2RT 7865-1 and 3RT-7865-1 which are not identified with any margin of-

' safety. Therefore, this proposed change will not significantly reduce any margin of safety. ,

L 1AFETY AND SIGNIFICANT HAZARDS DETERMINATION Based on the Safety Analysis, it is concluded that: (1)Theproposedchange-does not constitute a signifd: ant hazards consideration as defined by 10 CFR 7 there ,is reasonable assurance that the' health-and safety of the 50.92;.(2)l public wil not be endangered by the proposed change, (3) this action will-not result. inia condition which significantly alters the impact of the station on. ,

the environment as described in-the NRC Final Environmental Statement.

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