ML20099H504
| ML20099H504 | |
| Person / Time | |
|---|---|
| Site: | FitzPatrick  |
| Issue date: | 08/10/1992 |
| From: | POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK |
| To: | |
| Shared Package | |
| ML20099H496 | List: |
| References | |
| NUDOCS 9208190064 | |
| Download: ML20099H504 (13) | |
Text
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4 ATTACHMENT l to JPN-92-044 CURRENT TECHNICAL SPECIFICATIONS TO BE CHANGED REGARDING OFFGAS SYSTEM DILUTION FLOW SETPOINTS (JPTS-92-018)
P New York Power Authority JAMES A. FITZPATRICK NUCLEAR POWER PLANT Docket No. 50-333 9208190064 DR 920010 ADOCK 05000333 PDR
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1 LIMITING CONDITIONS FOR OPERATIOst f SuavEIr.r.m1 RE0tstassesrys treatment system ' eader the felleelag . ceedi- 1.
tiens s' a
' Am 'lostresset check shall be performed
. le daily eAee the ofigas ' treatment aystem {s operatioc.
- 1. The effgas 411stles steam flew lastresset- '
taties emani alasm .1 and :eetematically *
, l lee] ate ' the offges recombiner system at
- 2. Ao lastrument ch====1 functiesel test' Li les flee'less then per,heer shall be pericreed once per operating er high flow ~ greater cycle.
1 pounds per
' hear.
3.
2.
As lastrument ch-1 calibraties shall The offgas receableer. Jelet ' temperature senser. shall- alarm and . . aatematically 5
isolate the ' offges recombiner system 'at a -
temperatore of met 1wes then 125'C.
l 3. The offges receshleer ' eetlet temperature j
shall alarm and setematically laelate the l ef fges - treatment system at a tenyerature l
l et met'less then'156*C.
e
- c. la- 11ee of eestlemees hydroges er.. esygee c. With meelterlag, the he effges treatmoet condeemer effges treatmoet system
[- l system recombleer effisent shall - he analysed recombiner le service, le 11em of coetlemees hydrogee or esyges moeiterlag, the hydrogee l to'~werify that it costales less thea er egual . I j- to 4% hydrogen by welese. coeteet shall be verified meekly to be *ess thma er equal to 4% hy welmes.
- d. With- the requiressets of
- the aheve specificatione not satisfied, restore the In the evoet that the hydrogea coetent cosmet
,recombleer system" to withis operating he verified, operaties of , this system may specifications or suspeed use . of the charcoal M ier. *er op to 14 days.
treatment system within 48 heers.
i e
! Amendment No. g ; 127 33 I
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BASES IV.A. to assure that the releases of radioactive materials in gaseous affluents vill be kept "as lov as is reasonably achievable."
3.$ MAIN CD'fDENSER STEAM JIT ATR EJECTOR (SJAE)
This specification is provided to assure that remedial action is taken to limit the noble gas release rate at the SJAI. The requirement provides reasonable assurance that the amount of noble gas that must be treated and/or released it, controlled to a level that prevents exceeding the lim-its specified in 10 CTR 20. Appendix B. Table II.
Two air ejector offgas monitors are provided and when their trip point is reached, cause an isolation of the air ejector offgas line. Isolation is initiated when both instruments reach their high trip point or one has an upscale trip and the other a downscale trip. There is a 15 minute delay before the air ejector offges isolation valve is closed. This delay is accounted for by the 30 minute holdup time of the offgas before it is released to the stack. Both instruments are required for trip but the instruments are so designed that any insttament failure gives a downscale trip.
3.6 0FTCAS TREATMDrr SYSTIM This specification is provided to ensure that the system will be avail-able for use when required to reduce projected doses due to gaseous releases. This specification assures th.et the requirements of 10 CTR 50.36a, 10 CTR 30. Appendix A. Censral Design Criterion 60, and design objective in 10 CTR 50, Appendix 1. Section IT..D are met. The specified limits governing the use of appropriate porr,% : of the systems are spec ~ -
ified as a suitable fraction of the guide W Aas set forth in 10 CTR 50 Appendix I, Sections II.B and II.C. for gaseous effluents.
The requirement for offgas treatment system operability provides assur-ance that the release of radioactive materials in gaseous vaste vill be kept "as lov as is re . ably achievable." Operability of the system is based upon start-up oi 4 second turbine driven feedvater pump. This is due to the fact that excess air in-leakages in the main condenser as a result of operating only one turbine driven feedvater pump will exceed offgas treatment system limitations and consequently render the system inoperable. Start-up of the second turbine, driven feedvater pump will decrease air in-leakages and assure offgas treatment system availability.
3.7 0FTCAS TREATwENT SYSTEM EIpt0SIVE CAS MIXTURE INSTRITMDITATION This specification is provided to ensure that the concentration.of poten-tially explosive gas mixtures contained in portions of the offgas treat-ment system not designed to withstand a hydrogen explosion is maintained
/ below the lover explosive _11=it.of hydroge An.-W iip W operation et eng (pElmary recombiner ensures
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that the charcoal contained in the condenser j _ _ ,
Amendment No. 93 41
BASES (oUgastreatmentsystemisnot exposed to_an explosive afsidrT of gash Thu s ~it'~p rovid'e's~ a sib ~ranc e thai ~thi~ release s of Yadioliitife~taterials will be controlled in conformance with the requirements of,10 CTR 50 Appendix A. General Design Criterion J f j
. 3.8 C______ _il_ TREATMENT SYSTDi ($BCTS)
STANDBY C ygpfg7 Tour radiation monitors are 9rovided which initiate isolation of the reactor building and operatiik of the $3GTS. The nonitors are located as follows: two in the reactor building ventilation exhaust duct and two in refuel floor ventilation exhaust duct. Each pair is considered a separate system. The trip logic consists of any upst. ale trip on a single monitor or a downscale trip on both monitors in a pair to cause the desired ac-tion.
Trip . settings for the monitors in the refueling area ventilation exhaust ducts. are based upon initiating normal ventilation isolation and SBGTS operation so that most of the activity released during the refueling ac-cident is processed by the SBGTS.
The radiation monitors in the refueling area ventilation duct which ini-tiate building isolation and standby gas treat:nent operation are arranged in a one out of two logic system. The bases given in Appendix A Bases 4.2 for the rod blocks apply here also and were used to arrive at the fune-tional testing frequency. The air ejector offgas monitors are connected in a two out of two logic arrangement. Based on experience with instru-ments of similar design, a testing interval of once every three months has been found adequate.
3.9 MECHANICAL VACUCM PCMP ISOLATION 3.10 MAIN CONTR01. ROOM VENTILATION RADIATION MONITOR l
Anandment No. 93 42
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ATTACHMENT 11 to JPN-92-044 i
PROPOSED TECHNICAL SPECIFICATION CHANGES REGARDING OFFOAS SYSTEM DILUTION FLOW SETPOINTS (JPTS-92-018)
New York Power Authority JAMES A. FITZPATRICK NUCLEAR POWER PLANT Docket No. 50-333
UMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS treatment system under the following conditions:
- 1. An instrument check shall be performed daily Wm the gas system b in pah
- 1. The offgas dilution steam flow instrumentation shall alarm
, and automatically isolate the offgas recombiner system at 2. An instrument channel functional test shaII be performed low flow less than or equal to 6300 pounds per hour or once per operating cycle.
ll high flow greater than or equal to 7900 pounds per hour.
- 3. An instrument channel calibration shall be performed once
- 2. The offgas recombiner inlet temperature sensor shall alarm per operating cycle.
and automatically isolate the offgas recombiner system at I
a temperature of not less than 125 C.
- 3. The offgas recombiner outlet temperature shall alarm and automatically isolate the offgas treatment system at a temperature of not less than 150 C.
- c. In lieu of continuous hydrogen or oxygen monitoring, the c. With conder ser offgas treatment system recombiner in service.
condenser offgas treatment system recombiner effluent shall be in. lieu of continuous hydrogen or oxygen monitoring, the analyzed to verify that it contains less than or equal to 4% hydrogen content shall be verified weekly to be less than or hydrogen by volume. equal to 4 % by volume.
In the event that the hydrogen content cannot be verified,
- d. With the requirements of the above specifications not satisfied, operation of this system may continue for up to 14 days.
restore the recombiner system to within operating specifications or suspend use of the charcoal treatment system within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.
Amendment No. SPf,12T, 33
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BASES IV.A, to assuro that the ro!oasos of radioactivo materials in Datoous offluents will bo kept
'as low as is reasonably achievablo."
3.5 MAIN CONDENSER STEAM JET AIR EJECTOR (SJAE)
This specification is provided to assure that remedial action is taken to limit the nobio gas roloaso rato at the SJAE. The requltomont providos reasonablo assuranco that the amount of noble gas that must be treated and/or rolcased is controlled to a lovel that provents excooding the limits specified in 10 CFR 20, Appendix B, Tablo 11.
Two air ejector offgas monitors aro provided and when their trip point is reachod, causo an isolation of tho air ejector offgas lino. Isolation is initiated when both Instruments reach tholt high trip point or onc has an upscalo trip and the other a downscalo trip. Thoro is a 15 minuto delay before tho air ejector offgas isolation valvo is closed. This delay is accounted for by tho 30 minuto holdup timo of the offgas before it is retcased to the stack.
Buth instruments aro required for trip but the instruments are so designed that any instrument failuro gives a downscalo trip.
3.6 OFFGAS TREATMENT SYSTEM This specification is provided to ensure that the system will be available for use when required to reduce projected dosos due to gaseous roloasos. This specification assures that the requirements of 10 CFR 50.36a,10 CFR 50, Appendix A, General Design Criterion 00, and design objectivo in 10 CFR 50, Appendix 1, Section ll.D aro mot. The specified limits governing the uso of appropriato portions of the systems are specified as a suitablo fraction of the guido values set forth in 10 CFR 50, Appendix 1, Sections 11.B and ll.C, for gaseous offluents.
The requirement for offgas treatment system operability providos assuranco that the release of radioactivo materials in gaseous wasto will be kept *as low as is reasonably achievable." Operability of tho system is based upon start-up of the socmd turbino driven foodwater pump. This is due to the fact that excess air in-loakagos in the main condonsor as a result of operating only one turbino driven foodwater pump will exceed offgas treatment system limitations and consequently rondor the system inoperable. Start-up of the second turbino driven foodwater pump will decreaso air in-loakages and assure offgas treatment system availability.
3.7 OFFGAS TREATMENT SYSTEM EXPLOSIVE GAS MIXTURE INSTRUMENTATION This specification is provided to ensure that the concentration of potentially explosivo gas mixtutes contained in portions of tho offgas tmatment system not designed to withstand a hydrogon explosion is maintained below the ' s exolosivo limit of hydrogon. Operation of the offgas recombiner system onsures t ? tre concentration of hydrogen in the offgas
- charo al filters romains below combustibic a vols.
Amendment No. Sd, 41 l - - - _ - - - - - - - - - - - _ - - -
g
- BASES 1- ~
Thus it provides assurance that the releases of radioactive materials will be controlled in confommnce with the requirements of 10 CFR 50, Appendix A, General Design Criterion
- 60. TM sow steam flow trip point is based on 92% of design steara flow and reroutes the j offgas to prevent overheating or Ignition of the recombiner catalyst. The high steans flow trip point isolates the recombiner on excess steam flow that may be associated with a pipe s, - break downstream of the recombiner.
3.8 STANDBY GAS TREATMENT SYSTEM (SBGTS)
Four radiation monitors are provided which initiate isolation of the reactor building and operating of thn SBGTS. The monitors are located as follows: two in the reactor building ventilation oxlaust duct and two in refuel floor ventilation exhaust duct. Each pair is -
considered a separate system. The trip logic consists of any upscale trip on a single monitor or a downscale trip on both monitors in a pair to cause the desired action.
Trio settinos for the monitors in the refucting area ventilation exhaust ducts are based upon initiating normal ventilation isolation and SBGTS operation so that most of the activity released 'uring the refueling accident is processed by the SBGTS.
The radiation monitors in the refueling area ventilation duct which iretiate building isolation and standby gas ticatment operation are arranged in a one out of two logic system. The bases given in Appendix A Bases 4.2 for the rod blocks apply here also and were used to arrive at the functional testing frequency. The air ejector offgas monitors are connected in a two out of two logic arrangement. Based on experience with _ instruments of similar design, a testing interval of once overy three months has been found adequate.
3.9 MECHANICALV&CUUM PUMP ISOLATION 3.10 MAIN CONTROL ROOM VENTILATION RADIATION MONITOR Amendment No. p$,
42
A ATTACHMENT 1ll to JPN 92-044 SAFETY EVALUATION FOR PROPOSED TECHNICAL SPECIFICATION CHANGES REGARDING OFFGAS SYSTEM DILUTION FLOW SETPOINTS (JPTS-92-018) l New York Power Authority JAMES A. FITZPATRICK NUCLEAR POWER PLANT l: Docket No. 50-333 1
ATTACHMENT lil to JPN 92-044 SAFETY EVALUATION FOR PROPOSED TECHNICAL SPECIFICATION CHANGES OFFGAS SYSTEM STEAM DILUTION FLOW SETPOINTS (JPTS-92 018)
Pago 1 of 4
- 1. DESCRIPTION OF THE PROPOSED CHANGES The proposed changes to the James A. FitzPatrick Radiological Effluent Technical Specifications (RETS) reviso Section 3.7 and the corresponding bases. Specifically, pages 33,41 and 42 of the RETS contained in Volume 1B of the Technical Specifications are revised as follows:
Pago 33, Specification 3.7.b.1 E Replace the phraso " low flow less than 6000 pounds por hour or high flow greator than 7200 pounds per hour." with the phraso " low flow loss than or equal to 6300 pounds por hour or high flow greater than or equal to 7900 pounds por hour."
Pago 41, Bases 3.7 Replace the second sentence which currently roads, "The proper operation of the primary recombiner ensures that tho charcoal contained in the condensor offgas treatment system is not exposed to an explosive mixture of gases." with the following:
" Operation of the offgas recombiner system ensures that the concentration of hydrogen in the offgas charcoal filters remains below combustibio levels."
Pago 42, Bares 31 Add the following sentenco at the end of the section:
- The low steam flow trip point is based on 92% of design steam flow and reroutes tho offgas to provent overhosting or Ignition of the recombiner catalyst. The high steam flow trip point isolates the recombiner on excess steam flow that may be associated with a pipo broak downstream of the recombiner."
- 11. PURPOSE OF THE PROPOSED CHANGES c
The proposed change to Section 3.7.b.1 of the James A. FitzPatrick Radiological Effluent Technical Specifications increases the offgas dilution steam low flow and high flow setpoints to greater than or equal to 6300 and loss than or equal to 7900 pounds per hour respectively. Section 3.7 of the bases is also revised to describe more accurately the explosion protection function of the offgas system.
As described in Section 11.4c. : of the FSAR, the recombiner system roccives off gas (mainly noncondensables) from the main condenser and recombines the hydrogen and oxygen continuously to form steam. Beforo recombination, the gas mixture is diluted with steam to reduce the hydrogon concentration to less than 4% by volume. The dilution
"...will ensure that the gas mixturo is maintained below the flammable concentration for
. Attachment lit to JPN-92-044 SAFETY EVALUATION Pago 2 of 4 hydrogon." The recombinor system also roduces tho volume of cffgas to ensuro adoquato holdup timo for the docay of short lived radioactivo isotopos of nobio gases and lodino.
The primary method to ensure that the hydroger, concentration is within acceptablo limits in the recombiner is direct monitoring of this paramotor. If the continuous hydrogon monitor is not available, one of the altomato monitoring methods is to uso the dilution steam flow instrumont. Alarm and auto isolation of the recombiner are currently provided at low steam flow of loss than 6000 pounds por hour or high flow greator than 7200 pounds por hour. The low flow sotpoint ensures sufficient steam to provent overhoating or Ignition of the recombiner catalyst. The bl 0h flow setpoint ensures isolation of a postulated pipo broak downstream of the recombiner.
Recent sotpoint calculations identified that operation of the plant within the existing sotpoints can not be assured when instrument loop uncertainty is nonsidorod. To ensuro oporation within tho technical specifications limit whilo considering loop uncertainty, either tho instrumentation must be roplaced to reduce instrument uncertainty or tho technical specifications limit must be revised to provido a wider window for operation using the currently installed instrumentation, Changing the technical specifications setpoints is the more cost and time offectivo method of resolving this concern.
In addition, the planned reactor power uprato will increaso the radiolytic production of hydrogen by about 4% This will increaso the minimum roquired dilution steam flow and the corresponding low flow setpoint by about 4% This amendment application proposes to chango the low flow sotpolat from the present 6000 pounds por hour to 6300 pounds por hour. This represents a 5% increaso. The low flow sotpoint of 6300 lbs/hr follows the guidanco provided in General Electric Servico information Letter 150 (GE SIL 150), Rov. 2, which recommends that the low flow setpoint be set at a value no lower than 92% of the design steam flow requirod to koop tho gas mixturo below the hydrogen flammability limit.
The basis for the minimum valuo of 92% of the design steam flow, as recommended in GE SIL 150,is to prevent overheating or ignition of the catalyst. 92% of the current FitzPatrick design steam flow of 6508 lbs/hr results in a minimum setpoint of 5987 lbs/hr. With the power uprato design steam flow of 6770 lbs/hr, the minimum sotpoint becomes 6223 lbs/hr. Thereforo, the proposed setpoint of 6300 lbs/hr is conservativo for both the current licensed power lovel and for the plannod power uprato. f This amendment application also proposos to raise the upper sotpcint from 7200 to 7900 lbs/hr to provido an adoquate window for normal plant operations considering loop uncertainty whilo remaining within the range of the curtont instrumentation. The increaso in the amount of steam released in the ovent that a pipo break occurs with the now higher sotpoint in elfoct is insignificant. An enginocring evaluation was performed to verify that the recombiner will continuo to isolato adomatically within 5 seconds of a pipo break downstrcam of the recombiner, as described in Section 11.4.4.2 of the FSAR. The ovaluation concluded that the pipe break detection and isolation function will still be accomplished within 5 seconds with the now setpoirit.
Ill. SAFETY IMPLICATION OF THE PROPOSED CHANGES The proposed changes do not affect the ability of the offgas system to moet its safety design bases contained in Section 11.4.3 of the FSAR. Tho proposed amendment does not chango the assumptions or conclusions contained in the plant safety anatyses.
m Attachmont ::1 to JPN-92-044 SAFETY EVALUATION Page 3 of 4 The revised steam dilution low flow sotpoint will prevent overheating or ignition of the catalyst. The proposed valuo is consistent with the guidanco provided in GE SIL 150, Rev.
- 2. This proposed chango will also accommodate the increased quantity of hydrogen flow expected due to the planned power uprato. The proposed steam dilution high flow setpoint is sufficiently low to provido broak detection downstream of the recombiner as described in the FSAR. Although the low and high flow isolation sotpoints will be raised, actual dilution steam flow is expectnd ic remain unchanged for the current power level.
However, should steady stato dilution steam flow approach the revised high flow sotpoint, the additional steam can be removed in the offgas condenser and dryers. Thorofore, at the current power level, the amount of noncondensible gases entering the holdup piping and hence, holdup times remain unchanged.
The proposed changes to the baFos will clarify the safety function of the recombiner and the steam dilution flow setpoints. _
IV. EVALUATION OF SIGNIFICANT HAZARDS CONSIDERATION Operation of the FitzPatrick plant in accordance with the proposed Amendment would ara involve a significant hazards consideration as defined in 10 CFR 50.92, since it would not
- 1. involve a significant increase in the probability or consequences of an accident previously evaluated.
The offgas system is not used to mitigato any of the transients or the accidents described in the FSAR. The proposed chango increases the offgas dilution steam low flow and high flow sotooints to greater than or equal to 6300 and loss than or equal to 7900 pounds per hour respectively. The proposed setpoints do not change the normal operation of the system. The proposed steam dilution low setpoint will continue to ensure adequato steam flow through the recombiner during normal plant operation to prevent overheating or ignition of the catalyst. The proposed low setpoint follows the g' tidance provided in GE SIL 150, Rev. 2. which recommends that the low flow setpoint be set at a value no lower than 92% of the design steam ["
flow required to keep the process below the flammability limit. In addition, this vatuo is conservative for both the current licensed power level and for the planned power
- uprato. The proposed steam dilution high sotpoint will continue to provide recombiner isolation in the event of a break as described in the FSAR. If a postulated break occurs, the difference of the releaso between the old and new setpoint will be negligible. The proposed chango does not involvo a significant increase in the probability or consequences of an accident previously evaluated.
- 2. create the possibility of a new or dJferent kind of accident from any accident previously evaluated.
The proposed changes involve changing the instrument setpoints but do not change the operation of the offgas system or the ability of the recombiner to perform its intended function. The proposed changes will ensure sufficient steam to prevent overheating the recombiner catalyst as well as isolation and pipo break detection. l I
The changes do not introduce new equipment or any new failure modes to the plant.
Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
. Attachment lll to JPN 92414 SAFETY EVALUATION Pago 4 of 4
- 3. involve a significant reduction in a margin of safoty, increasing the existing low and high dlLdon flow setpoints will provido an adequate window for normal plant operation. The proposed changes will ensure that existing margin of safety will be maintained. The offgas system will continue to meet all of its safoty design bases as described in the FSAR. Changing the sotpoints values will ensure safo plant operation since the probabi!ity of hydrogen combustion within the offgas system remains unchanged and within acceptable levels. In addition, the isolation function will continue to be provided by the revised setpoints. The proposed setpoints will ensuro an adoquate operational band when instrument uncertainty is considered. Thorofore, the proposed chango does not involve a
. significant reduction in a margin of safety.
V. IMPLEMENTATION OF THE PROPOSED CH ANGE imptomentation of the proposed changes will not adversely affect the ALARA or Fire Protection Programs at the FitzPatrick plant, nor will the changos affoct the environment.
VI. CONCLUSION The changes, as proposed, do not constituto an unreviewod safety question as defined in 10 CFR 50.59. That is, they:
- 1. will not increase the probability nor the consequences of an accident or malfunction of equipment important to safety as previously evaluated in the Safety Analysis Report;
- 2. will not create the possibility of an accident or malfunction of a type different from any previously evaluated in the Safety Analysis Report;
- 3. will not reduce the margin of safety as defined in the basis for any technical specification; and
- 4. involve no significant hazards consideration, as defined in 10 CFR 50.92.
Vll. REFERENCES
- 1. James A. FitzPatrick Nuclear Power Plant Updated Final Safety Analysis Report, Section 11.4.
- 2. James A. FitzPatrick Radiological Effluent Technical Specifications, Section 3.7.
- 3. New York Power Authority Calculation JAF-CALL-OFG-00505, "Offgas Steam Dilution Flow Calculation *, dated May 6,1992.
- 4. General Electric Service Information Letter 150, Rev. 2, Sup. 3,
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