|
|
Line 27: |
Line 27: |
| During each refueling and each shutdown for required maintenance inside the containment, the containment is purged to restore a normal air atmosphere and to reduce the amount of gaseous and airborne radioactivity present. These purges are accomplished through the ventilation purge connections and are normally passed through a containment purge filter train (HEPA and charcoal filters) before release through the normal reactor building ventilation system. A vent from the primary containment is provided which will normally be closed, but which will permit the vent discharge to be routed to the Standby Gas Treatment System so that release of gases from the primary containment is controlled, and so that eNuents are filtered and monitored before dispersal through the stack. | | During each refueling and each shutdown for required maintenance inside the containment, the containment is purged to restore a normal air atmosphere and to reduce the amount of gaseous and airborne radioactivity present. These purges are accomplished through the ventilation purge connections and are normally passed through a containment purge filter train (HEPA and charcoal filters) before release through the normal reactor building ventilation system. A vent from the primary containment is provided which will normally be closed, but which will permit the vent discharge to be routed to the Standby Gas Treatment System so that release of gases from the primary containment is controlled, and so that eNuents are filtered and monitored before dispersal through the stack. |
| A 30-inch suction header with a wall thickness of 1/2-inch minimum circumscribes th'e suppression chamber at El, 525 feet 4 inches. Four 30-inch tees are used to connect the suction header to the suppression chamber. The suction header is supported vertically and horizontally by brackets attached to the 16 cradles. | | A 30-inch suction header with a wall thickness of 1/2-inch minimum circumscribes th'e suppression chamber at El, 525 feet 4 inches. Four 30-inch tees are used to connect the suction header to the suppression chamber. The suction header is supported vertically and horizontally by brackets attached to the 16 cradles. |
| Four strainers on connecting lines between the suction header and the suppression chamber have been provided. izi o e s nn ctin ew | | Four strainers on connecting lines between the suction header and the suppression chamber have been provided. izi o e s nn ctin ew s ve a a tion at tie ton ofth fou |
| '
| |
| s ve a a tion at tie ton ofth fou | |
| 'n the o lat a 'den. In ditio th str m et | | 'n the o lat a 'den. In ditio th str m et |
| 'p g curve th str 'ne in iz the os 'lity cl ing. | | 'p g curve th str 'ne in iz the os 'lity cl ing. |
|
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Category:TECHNICAL SPECIFICATIONS
MONTHYEARML18039A8811999-09-28028 September 1999 Proposed Tech Specs Re Increased MSIV Leakage Rate Limits & Exemption from 10CFR50,App J ML18039A8241999-07-28028 July 1999 Proposed Tech Specs Providing TS for Operation of Oscillation PRM Upscale Trip Function in Aprm,Which Is Part of Power Range Neutron Monitoring Sys ML18039A8001999-06-0303 June 1999 Proposed Tech Specs,Reducing Allowable Value Used for Reactor Vessel Water Level - Low,Level 3 for Several Instrument Functions ML18039A6991999-02-22022 February 1999 Proposed Tech Specs & Bases Pages Incorporating NRC Approved TS Change 354,requiring Oscillation PRM to Be Integrated Into Approved Power uprate,24-month Operating Cycle & Single Recirculation Loop Operation ML18039A6601998-12-15015 December 1998 Proposed Tech Specs,Revising pressure-temp Curves to Extend Validity of Curves to 32 EFPY ML18039A5041998-09-0808 September 1998 Proposed Tech Specs Providing TS for Operation of Oscillation Power Range Monitor Upscale Trip Function in Aprm,Which Is Part of Power Range Neutron Monitoring Sys ML18039A5001998-09-0404 September 1998 Proposed Tech Specs Re Use of Containment Overpressure for ECCS Pump Net Positive Suction Head Analyses ML18039A4791998-08-14014 August 1998 Proposed Tech Specs Pages Re Amends to Licenses DPR-33, DPR-52 & DPR-68 to Change Ts.Proposed Changes Decrease Frequency of once-per-cycle Instrument Calibrations by Substituting 24 Months for 18 Months ML18039A4611998-07-31031 July 1998 Proposed Tech Specs B 3.6-2,B 3.6-7 & B 3 3.7-2 for Power Uprate Operation Omitted Pages ML18039A4481998-07-17017 July 1998 Proposed Tech Specs,Adding LCO 3.4.10 & Accompanying TS Bases Provisions from Improved TS-362 Conversion Package as Adapted for Power Uprate Conditions ML18039A4091998-06-26026 June 1998 Proposed Tech Specs Section 3.4,allowing Units 2 & 3 to Operate at Uprated Power Level of 3458 Mwt ML18039A4021998-06-19019 June 1998 Proposed Tech Specs (TS) Converting from Existing Custom TS to Improved TS ML18039A3921998-06-12012 June 1998 Proposed Tech Specs Change 390,decreasing Frequency of once-per-cycle SRs by Substituting 24 Months for 18 Months in Affected TS SRs ML20249A5661998-06-10010 June 1998 Proposed Tech Specs Section 5.0,revising Administrative Controls ML20248C5151998-05-27027 May 1998 Proposed Tech Specs Section 3.8.1,revising AC Sources- Operating ML18039A3181998-04-16016 April 1998 Proposed Rev 2 to Tech Specs Section 3.6, Containment Systems, Converting from Current TS to Improved TS ML18039A2711998-03-16016 March 1998 Proposed Tech Specs Re Power Uprate Operation ML18039A2671998-03-13013 March 1998 Proposed Tech Specs,Converting to Improved Std Ts,Per NUREG- 1433,rev 1, Std TS for GE BWRs (BWR/4). ML18039A2641998-03-12012 March 1998 Proposed Tech Specs ITS Section 3.8 Re Electrical Power Sys. ML18039A2611998-03-0303 March 1998 Proposed Tech Spec Changes TS 393 Re Reactor Vessel Pressure Temperature Curves ML20199E8051998-01-23023 January 1998 Proposed Tech Specs Section 5.0 Re Administrative Controls ML18039A2221997-12-30030 December 1997 Proposed Tech Specs Re RHR SW Pumps Required for multi-unit Operation & Cold Shutdown ML18039A2151997-12-23023 December 1997 Proposed Tech Specs Section 3.7 Re Plant Sys ML18039A2181997-12-22022 December 1997 Proposed Tech Specs Section 3.8 Re Electrical Power Sys ML18039A2101997-12-0404 December 1997 Proposed Tech Specs Pages Re TS Change 362,suppl 7 Re ITS Section 3.1, Reactivity Control Sys. ML18039A2071997-12-0404 December 1997 Proposed Tech Specs Pages Re Suppl 9 to TS Change 362, Including Rev Pages to Improved TS Section 3.5 ML18039A2011997-12-0303 December 1997 Proposed Tech Specs Section 3.9 Re Refueling Operations & Section 3.10, Special Operations. ML18039A1981997-12-0303 December 1997 Improved Tech Specs Pages Re Section 5, Administrative Controls. ML20199D5471997-11-14014 November 1997 Proposed Tech Specs Section 3.0, Limiting Condition for Operation (LCO) Operability & Section 4.0, Design Changes ML20199E1361997-11-14014 November 1997 Proposed Tech Specs Section 3.4 Re Reactor Coolant Sys ML20198Q4521997-11-0505 November 1997 Proposed Tech Specs,Incorporating Improved TS (ITS) Bases Revs & Changes to Supporting Documentation Resulting from Responding to NRC Questions ML18038B9611997-10-0101 October 1997 Proposed Tech Specs,Allowing Bfn,Units 2 & 3,to Operate at Uprated Power Level of 3458 Mwt ML18038B9361997-08-15015 August 1997 Proposed Tech Specs,Extending Existing 7-day EDG Allowed Outage Time to Fourteen Days ML18038B9061997-06-19019 June 1997 Proposed Tech Specs Supporting one-time 14-day Limiting Condition for Operation for Each EDG to Accommodate Pending Vendor Recommended Maint Activities ML20138J3781997-05-0101 May 1997 Proposed Tech Specs,Revising TS-362 Amend for Section 3.8, Electrical Power Sys Which Addresses NRC Review Comments ML18038B8651997-04-24024 April 1997 Proposed Tech Specs,Submitting Revised BFN TS Bases Section 3.5.N, References, Reflecting Updated LOCA Analyses for Units 2 & 3 ML20137U1691997-04-11011 April 1997 Proposed Tech Specs Re Pr Neutron Monitor Upgrade W/ Implementation of Average Pr Monitor & Rod Block Monitor TS (ARTS) Improvements & Max Extended Load Line Limit Analyses ML18038B8341997-03-12012 March 1997 Proposed Tech Specs Re Extended EDG Allowed Outage Time ML20136F7851997-03-0606 March 1997 Proposed TS Supporting Planned Replacement of Current Power Range Monitoring Portion of Existing Nms W/Ge Digital Nuclear Measurement Analysis & Control Power Range Neutron Monitor Retrofit Design ML20134G5401997-02-0505 February 1997 Proposed Tech Specs Revising Bases Section 3.7.A/4.7.A, Primary Containment, to Delete Wording Re Maintaining Drywell to Suppression Chamber Differential Pressure Constant for Duration of Drywell to Suppression Chamber ML20132B7401996-12-11011 December 1996 Proposed Tech Specs 2.2.A Re Safety/Relief Valve Setpoint Requirements for Reactor Coolant Sys Integrity ML20117P3341996-09-15015 September 1996 Proposed Tech Specs to Change Unit 3 TS LCO 3.6.F.1 in Order to Perform Repairs & Maint Necessary to Return RCS Recirculation Loop a to Operations ML18038B7541996-09-0606 September 1996 Proposed Conversion from Current TSs to Improved STS Consistent w/NUREG-1433,rev 1 ML20117G7121996-08-30030 August 1996 Proposed Tech Specs Re License Condition on Compliance W/Thermal Water Quality Stds ML20113B1951996-06-21021 June 1996 Proposed Tech Specs,Revising Change in SLMCPR & Bases Description of RHR Suppl Fuel Pool Cooling Mode ML20112G3891996-06-0606 June 1996 Proposed Tech Specs,Revising Section 6, Administrative Controls, to Be More Closely Aligned W/Requirements of Improved Std TSs ML20117H5231996-05-20020 May 1996 Proposed Tech Specs Implementing Guidance of GL 87-09 & NUREG-1433,Rev 1 ML20108D9021996-05-0303 May 1996 Proposed Tech Specs,Withdrawing Amend 219,temporary TS 343T, Rv Water Level Instrumentation & Amend 228,temporary TS 347T,250 Volt DC Control Power Supply Sys AOT for Unit 2 ML20107F9721996-04-14014 April 1996 Proposed Tech Specs,Revising Minimum Required Number of Operable Rv Water Level Trip Sys During Period That RCS Instrument Line Excess Flow Check Valve Surveillance Tests Being Performed ML20096C4401996-01-10010 January 1996 Proposed Tech Specs Re Implementation of 10CFR50,App J, Option B,Performance Based Testing 1999-09-28
[Table view] Category:TECHNICAL SPECIFICATIONS & TEST REPORTS
MONTHYEARML18039A8811999-09-28028 September 1999 Proposed Tech Specs Re Increased MSIV Leakage Rate Limits & Exemption from 10CFR50,App J ML18039A8241999-07-28028 July 1999 Proposed Tech Specs Providing TS for Operation of Oscillation PRM Upscale Trip Function in Aprm,Which Is Part of Power Range Neutron Monitoring Sys ML18039A8001999-06-0303 June 1999 Proposed Tech Specs,Reducing Allowable Value Used for Reactor Vessel Water Level - Low,Level 3 for Several Instrument Functions ML18039A6991999-02-22022 February 1999 Proposed Tech Specs & Bases Pages Incorporating NRC Approved TS Change 354,requiring Oscillation PRM to Be Integrated Into Approved Power uprate,24-month Operating Cycle & Single Recirculation Loop Operation ML18039A6601998-12-15015 December 1998 Proposed Tech Specs,Revising pressure-temp Curves to Extend Validity of Curves to 32 EFPY ML20206F8131998-12-0303 December 1998 Rev 12 to ODCM, for BFN ML18039A5041998-09-0808 September 1998 Proposed Tech Specs Providing TS for Operation of Oscillation Power Range Monitor Upscale Trip Function in Aprm,Which Is Part of Power Range Neutron Monitoring Sys ML18039A5001998-09-0404 September 1998 Proposed Tech Specs Re Use of Containment Overpressure for ECCS Pump Net Positive Suction Head Analyses ML18039A4791998-08-14014 August 1998 Proposed Tech Specs Pages Re Amends to Licenses DPR-33, DPR-52 & DPR-68 to Change Ts.Proposed Changes Decrease Frequency of once-per-cycle Instrument Calibrations by Substituting 24 Months for 18 Months ML18039A4611998-07-31031 July 1998 Proposed Tech Specs B 3.6-2,B 3.6-7 & B 3 3.7-2 for Power Uprate Operation Omitted Pages ML18039A4481998-07-17017 July 1998 Proposed Tech Specs,Adding LCO 3.4.10 & Accompanying TS Bases Provisions from Improved TS-362 Conversion Package as Adapted for Power Uprate Conditions ML18039A4091998-06-26026 June 1998 Proposed Tech Specs Section 3.4,allowing Units 2 & 3 to Operate at Uprated Power Level of 3458 Mwt ML18039A4021998-06-19019 June 1998 Proposed Tech Specs (TS) Converting from Existing Custom TS to Improved TS ML18039A3921998-06-12012 June 1998 Proposed Tech Specs Change 390,decreasing Frequency of once-per-cycle SRs by Substituting 24 Months for 18 Months in Affected TS SRs ML20249A5661998-06-10010 June 1998 Proposed Tech Specs Section 5.0,revising Administrative Controls ML20248C5151998-05-27027 May 1998 Proposed Tech Specs Section 3.8.1,revising AC Sources- Operating ML18039A3181998-04-16016 April 1998 Proposed Rev 2 to Tech Specs Section 3.6, Containment Systems, Converting from Current TS to Improved TS ML18039A2711998-03-16016 March 1998 Proposed Tech Specs Re Power Uprate Operation ML18039A2671998-03-13013 March 1998 Proposed Tech Specs,Converting to Improved Std Ts,Per NUREG- 1433,rev 1, Std TS for GE BWRs (BWR/4). ML18039A2641998-03-12012 March 1998 Proposed Tech Specs ITS Section 3.8 Re Electrical Power Sys. ML18039A2611998-03-0303 March 1998 Proposed Tech Spec Changes TS 393 Re Reactor Vessel Pressure Temperature Curves ML20199E8051998-01-23023 January 1998 Proposed Tech Specs Section 5.0 Re Administrative Controls ML18039A2401998-01-15015 January 1998 Bfnp Unit 2 Cycle 10 Power Ascension Test Program Start-Up Rept, for Period 970929-1105 ML18039A2221997-12-30030 December 1997 Proposed Tech Specs Re RHR SW Pumps Required for multi-unit Operation & Cold Shutdown ML18039A2151997-12-23023 December 1997 Proposed Tech Specs Section 3.7 Re Plant Sys ML18039A2181997-12-22022 December 1997 Proposed Tech Specs Section 3.8 Re Electrical Power Sys ML20217P5051997-12-0808 December 1997 Rev 10 to ODCM, Containing Markups to Rev 9 & 10 ML18039A2101997-12-0404 December 1997 Proposed Tech Specs Pages Re TS Change 362,suppl 7 Re ITS Section 3.1, Reactivity Control Sys. ML18039A2071997-12-0404 December 1997 Proposed Tech Specs Pages Re Suppl 9 to TS Change 362, Including Rev Pages to Improved TS Section 3.5 ML18039A2011997-12-0303 December 1997 Proposed Tech Specs Section 3.9 Re Refueling Operations & Section 3.10, Special Operations. ML18039A1981997-12-0303 December 1997 Improved Tech Specs Pages Re Section 5, Administrative Controls. ML20199D5471997-11-14014 November 1997 Proposed Tech Specs Section 3.0, Limiting Condition for Operation (LCO) Operability & Section 4.0, Design Changes ML20199E1361997-11-14014 November 1997 Proposed Tech Specs Section 3.4 Re Reactor Coolant Sys ML20198Q4521997-11-0505 November 1997 Proposed Tech Specs,Incorporating Improved TS (ITS) Bases Revs & Changes to Supporting Documentation Resulting from Responding to NRC Questions ML18038B9611997-10-0101 October 1997 Proposed Tech Specs,Allowing Bfn,Units 2 & 3,to Operate at Uprated Power Level of 3458 Mwt ML18038B9361997-08-15015 August 1997 Proposed Tech Specs,Extending Existing 7-day EDG Allowed Outage Time to Fourteen Days ML20210V1171997-07-29029 July 1997 Qualification Plan & Rept MIL-STD-462D,CS114,Conducted Susceptibility,Bulk Cable Injection Numac Reactor Bldg Vents Radiation Monitor TVA Bfn,Units 1,2 & 3 ML18038B9061997-06-19019 June 1997 Proposed Tech Specs Supporting one-time 14-day Limiting Condition for Operation for Each EDG to Accommodate Pending Vendor Recommended Maint Activities ML20138J3781997-05-0101 May 1997 Proposed Tech Specs,Revising TS-362 Amend for Section 3.8, Electrical Power Sys Which Addresses NRC Review Comments ML18038B8651997-04-24024 April 1997 Proposed Tech Specs,Submitting Revised BFN TS Bases Section 3.5.N, References, Reflecting Updated LOCA Analyses for Units 2 & 3 ML20137U1691997-04-11011 April 1997 Proposed Tech Specs Re Pr Neutron Monitor Upgrade W/ Implementation of Average Pr Monitor & Rod Block Monitor TS (ARTS) Improvements & Max Extended Load Line Limit Analyses ML18038B8341997-03-12012 March 1997 Proposed Tech Specs Re Extended EDG Allowed Outage Time ML20136F7851997-03-0606 March 1997 Proposed TS Supporting Planned Replacement of Current Power Range Monitoring Portion of Existing Nms W/Ge Digital Nuclear Measurement Analysis & Control Power Range Neutron Monitor Retrofit Design ML20134G5401997-02-0505 February 1997 Proposed Tech Specs Revising Bases Section 3.7.A/4.7.A, Primary Containment, to Delete Wording Re Maintaining Drywell to Suppression Chamber Differential Pressure Constant for Duration of Drywell to Suppression Chamber ML18038B8281997-01-31031 January 1997 Rev 1 to GE-NE-B13-01805-22, Internal Core Spray Line Flaw Evaluation Handbook for Browns Ferry Units 2 & 3. ML18038B8111997-01-22022 January 1997 Rev 0 to Browns Ferry Nuclear Plant,Surveillance Instruction,Inservice Insp Program,Unit 3. ML20132B7401996-12-11011 December 1996 Proposed Tech Specs 2.2.A Re Safety/Relief Valve Setpoint Requirements for Reactor Coolant Sys Integrity ML20117P3341996-09-15015 September 1996 Proposed Tech Specs to Change Unit 3 TS LCO 3.6.F.1 in Order to Perform Repairs & Maint Necessary to Return RCS Recirculation Loop a to Operations ML18038B7541996-09-0606 September 1996 Proposed Conversion from Current TSs to Improved STS Consistent w/NUREG-1433,rev 1 ML20117G7121996-08-30030 August 1996 Proposed Tech Specs Re License Condition on Compliance W/Thermal Water Quality Stds 1999-09-28
[Table view] |
Text
ENCLOSURE 2 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)
UNITS 2 AND 3 PROPOSED LICENSE AMENDMENT MARKED PAGES I. AFFECTED PAGE LIST The following Amendment 16 Updated Final Safety Analysis pages have been revised. A revision bar has been placed in the right hand margin to indicate where the changes occurs Pacae Section 5.2-7 5.2.3.3.1 General Description 6.5-15 6.5.5 Potential Plugging of Emergency Core Cooling System Suction Strainers (Units 2 and 3)
Table
- 6. 5-7 RHR and CS Pump NPSH Cases With Credit For 3 PSIG Overpressure Response 9809'150303 980904 PDR ADOCK 05000260 P PDR
The system to establish and maintain a controlled pressure differential between the drywell and pressure suppression chamber during normal operations is described in paragraph 5.2.3.9.
The toroidal suppression chamber is designed to the same material and code requirements as the steel drywell vessel. All attachments to the torus are by full penetration welds.
The HWWV can mitigate a severe accident that would cause the pressure of the torus to exceed 56 psig. The HWWV connects the torus of each unit to a common header which discharges in the stack via a 14" pipe.
During each refueling and each shutdown for required maintenance inside the containment, the containment is purged to restore a normal air atmosphere and to reduce the amount of gaseous and airborne radioactivity present. These purges are accomplished through the ventilation purge connections and are normally passed through a containment purge filter train (HEPA and charcoal filters) before release through the normal reactor building ventilation system. A vent from the primary containment is provided which will normally be closed, but which will permit the vent discharge to be routed to the Standby Gas Treatment System so that release of gases from the primary containment is controlled, and so that eNuents are filtered and monitored before dispersal through the stack.
A 30-inch suction header with a wall thickness of 1/2-inch minimum circumscribes th'e suppression chamber at El, 525 feet 4 inches. Four 30-inch tees are used to connect the suction header to the suppression chamber. The suction header is supported vertically and horizontally by brackets attached to the 16 cradles.
Four strainers on connecting lines between the suction header and the suppression chamber have been provided. izi o e s nn ctin ew s ve a a tion at tie ton ofth fou
'n the o lat a 'den. In ditio th str m et
'p g curve th str 'ne in iz the os 'lity cl ing.
The suction header and its connecting pipes are designed, constructed, tested, and inspected in accordance with the same requirements as the suppression chamber. Additional safety is provided by locating the four connecting pipes in unused portions of the suppression chamber so that they will not be directly, subjected to the water jet issuing from the downcomers. The suction header is designed to accommodate a temperature differential between itself and.the suppression chamber. Hydraulic snubbers are used to support the suction header to provide seismic supports that will prevent any abrupt lateral movement, due to earthquake, but will not offer resistance to relatively slow thermal 5.2-7
6.5.3.4 Alternate 0 eratin Mode Considerations The impact of alternate operating modes on LOCA results is evaluated by analyzing the limiting LOCA case at such operating conditions as: Increased Core Flow (ICF),
Maximum Extended Load Line Limit (MELLL), and Final Feedwater Temperature Reduction (FFWTR)." For ICF and FFWTR, the impact on LOCA results is negligible. The Appendix K PCT at MELLLcore flow conditions is approximately 20'F higher, which is insignificant relative to the PCT margin available at the rated core flow conditions, with respect to the 2200'.F limit.
6.5.4 Emer enc Core Coolin S stems Redundanc The design criterion of preventing peak cladding temperatures greater than 2200'F is satisfied across the entire spectium of possible liquid or steamline break sizes even in the event of the loss of normal auxiliary power combined with a single failure. It is concluded that the redundant capability of the ECCS is sufficient for all size line breaks up to and including the design basis break.
The individual functions of the ECCS also meet the design criteria over various ranges of break sizes in the nuclear system. Their integrated performance provides adequate and timely core cooling over the entire spectrum of loss-of-coolant accidents up to and including the design basis loss-of-coolant accident even with concurrent loss of offsite AC power. It is concluded that safety design basis 1 is satisfied.
p~~pq<< i < ~ )i~
$ po.<~rg
~ ~~ inc WAS' C<rC C<>le S 6.5-15
Insert A:
Four strainers on connecting lines between the suction header and the suppression chamber have been provided.
For Units 2 and 3, the strainers are a stacked disk design having a large surface area to accommodate debris that may be generated by the dynamic forces in a LOCA and other debris that may be resident in the containment such as sludge and paint chips. The Unit 2 and 3 strainer design is governed by debris generation assumptions in accordance with the Boiling Water Reactor Operating Group Utility Resolution Guidance for ECCS Suction Strainer Blockage (GE NED0-32686, RO, Dated November 1, 1996). The strainers are designed to provide acceptable head loss while saturated with reflective metal insulation from primary system piping combined with other debris.
On Unit 1 only, sizing of the strainers and connecting pipes was conservatively based on the assumption that at least one of the four strainers was completely plugged during the postulated accident. In addition, the curves surface and location of the strainer minimize the possibility of clogging.
Insert B:
Add the Followin Pro osed Section to UFSAR Cha ter 6:
6.5.5 Potential Plu in of Emer enc Core Coolin S stem Suction Strainers (Units 2 and 3)
NRC Bulletin 96-03 concerns the potential for inadequate NPSH for ECCS pumps resulting from accumulated debris on the ECCS suction strainers during the recirculation phase of a LOCA. As part of the resolution of this issue, a high capacity passive stacked disk strainer is installed on the ring header. The strainer design is governed by the debris generation calculations in accordance with the Boiling Water Utility Resolution Guidance (BWROG) (URG) (GE NED0-32686, RO, Dated November 1, 1996) for ECCS Suction Strainer Blockage.
The primary insulation type on, the drywell piping systems is reflective metal insulation (RMI) of both aluminum and stainless steel. The suction strainers provide adequate NPSH margin with a saturated thickness of foils of either aluminum or stainless steel insulation. The debris generation calculations utilize BWROG URG assumptions and assume worst case debris loading during a postulated accident. Debris captured by the strainer during a E2-4
postulated LOCA will increase the pressure drop across the strainers.
The low pressure ECCS systems are designed to provide adequate NPSH for the pumps during the full range of post accident operation and containment pressure and temperature response. Credit is taken for 3 psi above atmospheric in the primary containment air space and it is assumed that operators take manual control of ECCS systems at 10 minutes after an accident to reduce flow to the minimum required. Table 6.5-7 provides the NPSH values and system configurations Containment pressure response analyses evaluated the suppression pool temperature and suppression chamber airspace pressure responses for the limiting short-term and long-term LOCA events with respect to available NPSH for the RHR and CS pumps. Input assumptions maintain the overall conservatism in the evaluation by maximizing the suppression pool temperature and minimizing the suppression chamber airspace pressure, and, therefore; minimize the available NPSH. These analyses show that at least 3 psi overpressure would be present in accident conditions when it is needed to offset the effect of debris on the strainers.
Table 6.5-7 provides a computation of limiting plant condition descriptions and NPSH at the pump for these selected analyzed conditions.
E2-5
PROPOSED TABLE 6.5-7 RHR AND CORE SPRAY PUMP NPSH CASES WITH CREDIT FOR 3 PSIG OVERPRESSURE RHR PUMP PUMP CS PUMP PUMP NPSH NPSH NPSH SPRAY CORE SPRAY NPSH AVAILABLE 1nitial ECCS RHR PUMP FLOW CONDITION 2 pumps on one 11,000 gpm (x2) 30'HR RHR PUMP FLOW RATE REQUIRED (FEET)
AVAILABLE PUMP FLOW (FEET) 32.05'ORE CONDITION 2 pumps on PUMP FLOW RATE 3,125 gpm 27'S REQUIRED (FEET)
(FEET) 35.77/
Start-Maximum flo loop at maximum 22,000 gpm each loop 8 (x4) =
limited by flow limited by plus 10, 000 gpm design flow 12,500 gpm orifices in one orifices and 2 (x2) =20, 000 gpm RHR loop and pumps on one Total Flow design flow in loop at design 42,000 gpm other RHR and CS flow loops. (in LPCI Mode)
Suppression Pool at 95F At 10 minutes, 2 pumps on one 11,000 gpm (x2) pumps on 3125 GPM LPCI maximum flow loop at maximum 22,000 gpm each loop 8 (x4) ~
in one RHR Loop, flow limited by plus 10, 000 gpm design flow 12,500 GPM CS at normal orifices and 2 (x2) ~20, 000 gpm 30'4'2.74'6.
design flow. pumps on one Total Flow 27'7'6.54'3.56I Suppression Pool loop at design 42, 000 gpm at 150'F flow (in LPCI Mode)
Long Term ECCS 2 pumps on one 6,500 gpm 89' 2 puIILps on 3125 gpm pump flows at pea loop at design (x2)=13,000 gpm one loop at (x2) =
suppression flow design flow 6250 gpm chamber (Containment temperatures cooling)
(177 F) 1 No credit taken for overpressure at time ~ 0 seconds.
- 2. Assumes 3 psig overpressure at time ~600 seconds