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Category:TECHNICAL SPECIFICATIONS
MONTHYEARML20210J1751999-07-30030 July 1999 Marked-up TS Pages for Proposed Changes Re Upper Temp Limit for UHS ML20209B7411999-06-30030 June 1999 Proposed Tech Specs Section 3.8.5, DC Sources - Shutdown, Correcting LCO & Braidwood TS Section 3.8, Electrical Power Systems, Deleting Various References to At&T Batteries ML20204H9781999-03-23023 March 1999 Proposed Tech Specs,Revising Sections 3.7.15,3.7.16,4.3.1 & 4.3.3 to Support Installation of New Boral high-density SFP Storage Racks at Byron & Braidwood Stations ML20204H4291999-03-22022 March 1999 Proposed Tech Specs 3.9.3,allowing Use of Gamma-Metrics post-accident Neutron Monitors to Provide Neutron Flux Info During Operational Mode 6 ML20198N2041998-12-29029 December 1998 Revised Tech Specs Change,Page 3/4 3-54,providing Early Implementation of Containment Floor Drain Sump Water Level Instrumentation Requirements ML20198N3471998-12-29029 December 1998 Proposed ITS Tables 3.3.1-1 & 3.3.2-1,revising Twelve Allowable Values ML20198K5841998-12-23023 December 1998 Revised Tech Spec Pages 3/4 3-53,3/4 3-53a,6-27 & 6-27a,for Rv LI Sys ML20198A0811998-12-14014 December 1998 Proposed Rev T to Improved Tech Specs Section 3.4, Reactor Coolant Sys ML20196G6611998-11-30030 November 1998 Proposed Rev to Improved Tech Specs Section 3.1 ML20196B4101998-11-25025 November 1998 Proposed Tech Specs Facilitating Replacement of 125 Vdc At&T Batteries with New 125 Vdc C&D Batteries While in Mode 1-4 ML20155J2051998-11-0505 November 1998 Proposed TS Converting to Its,Rev R ML20155J0041998-10-30030 October 1998 Proposed Tech Specs Section 5.6.2, Fuel Storage Drainage, to Identify Sf Pool Level Sufficient to Ensure SRP Acceptance Criteria ML20154S5011998-10-18018 October 1998 Proposed Rev N to Improved TS Section 3.7 ML20154M5281998-10-15015 October 1998 Revisions K,O & P of 961213 ITS Submittal ML20154A8881998-10-0202 October 1998 Proposed Rev L to Improved Tech Specs Section 3.8 Closeout ML20153G4331998-09-25025 September 1998 Revs J & M to Tech Specs Sections 3.6 & 5.0,converting to Improved Tech Specs (Its),Final Closeout Package ML20236W5851998-07-31031 July 1998 Proposed Rev G to Sections 3.1 & 3.2 of Improved Tech Specs ML20237B6391998-07-30030 July 1998 Proposed Rev H to Section 3.5 of Improved Tech Specs ML20237E9971998-07-21021 July 1998 Rev I to Proposed Improved Tss,Section 3.9 Re Final Closeout ML20237B7021998-07-0909 July 1998 Proposed Improved TS (ITS) Section 3.3 Issued as Result of Removing Generic Change Traveler TSTF-135,Rev E from ITS Submittal ML20236H6531998-07-0202 July 1998 Rev F to 961213 Improved TS Submittal,Containing Final Package Closeout for Improved TS Sections 1.0,2.0 & 3.0 ML20248M1491998-06-0101 June 1998 Proposed Tech Specs Bases Page B 3.8-58b,converting to Improved Tech Specs ML20248C5511998-05-29029 May 1998 Proposed Tech Specs Bases Section 3/4.4.4, Relief Valves, Specifically Crediting Automatic Function of PORVs to Provide Mitigation for Inadvertent Operation of ECCS at Power Accident ML20216D9431998-04-0909 April 1998 Modified Proposed TS Pages Re 980324 Request for Amends to Licenses NPF-37 & NPF-66 ML20217E1891998-03-24024 March 1998 Proposed Tech Specs Surveillance Sections & Bases Allowing Util to Defer 10CFR50,App J,Type a Testing of Byron Unit 2 Containment Until Next Refuel Outage in 1999 ML20217B2681998-02-14014 February 1998 Proposed Rev D to ITS ML20198L8811998-01-14014 January 1998 Proposed Tech Specs Pages,Revising TS Section 3/4.8.2 & Bases,To Allow Replacement of 125 Volt Dc At&T Batteries W/New Charter Power Sys,Inc (C&D) Batteries ML20198L8131998-01-14014 January 1998 Proposed Tech Specs Pages Revising TS 3.4.8, Specific Activity, Figure 3.4-1,Table 4.4-4 & TS Bases 3.4.8 ML20198C3181997-12-30030 December 1997 Proposed Tech Specs 3.7.1.3 Re Condensate Storage Tank ML20203M5921997-12-17017 December 1997 Proposed Tech Specs,Rev C Changes Improved TSs 3.0,3.3,3.7, 3.8 & 5.0 as Result of Removing Generic Change Traveler TSTF-115 from Improved TS Submittal ML20203D0361997-12-0909 December 1997 Proposed Tech Specs Pages Correcting Errors Discovered in Current TS W/Regards to Total RCS Volume & Correction to Increase in RCS Volume Associated W/Unit 1 Replacement SGs Accounting for Hot Conditions ML20199A4751997-11-0707 November 1997 Proposed Tech Specs Pages Revising TS Surveillance Sections 4.6.1.1.c,4.6.1.2.a,4.6.1.2.c & Bases to Allow Performance of 10CFR50 App J,Type a Testing ML20217K4461997-10-21021 October 1997 Proposed Tech Specs Re Boron Credit in SFP ML20202F4561997-10-10010 October 1997 Proposed Tech Specs,Deleting Lower Flow Rate Requirement Associated W/Nonaccessible Area Exhaust Filter Plenum & Fuel Handling Bldg Ventilation Sys ML20211D9421997-09-24024 September 1997 Proposed Tech Specs Revising Allowable Time Interval for Performing Turbine Throttle Valve & Turbine Valve SRs Requirements from Monthly to Quarterly ML20216G8541997-09-0808 September 1997 Proposed Tech Specs Change to TS 4.5.2.b & Associated Bases Bringing Byron Unit 1 & Braidwood Unit 1 Requirement in Conformance W/Unit 2 Requirements Approved by NRC in ML20216F1351997-09-0202 September 1997 Proposed Tech Specs 3.4.8 Re Specific Activity ML20217H6071997-08-0707 August 1997 Proposed Tech Specs Pages,Revising Bases for Proposed Improved TS SR 3.8.6.1 & 3.8.6.3,to Indicate That Correction for Level Is Not Required When Battery Charging Current Is Less than 2 Amps for Gould & Less than 3 Amps for C&D ML20148P7721997-06-30030 June 1997 Proposed Tech Specs,Revising TS 3.9.11,5.6.1.1 & 6.9.10 to Allow Util to Permanently Take Credit for Soluble B in Spent Fuel Storage Pool Water to Maintain Acceptable Margin of Subcriticality ML20141F3081997-06-24024 June 1997 Proposed Tech Specs,Changing TS for ECCS Venting ML20141B7781997-06-17017 June 1997 Proposed Tech Specs Revising TS Sections 3/4.6.1.6,4.6.1.2, 6.8.4 & 6.9.1.11 to Support New Requirements in 10CFR50.55a, Which Requires Utils to Update Existing Containment Vessel Structural Integrity Programs ML20148J3231997-06-0909 June 1997 Proposed TS Reflecting Latest Rev of Waste Gas Decay Tank Rupture Accident Dose Calculation ML20140D0081997-05-31031 May 1997 Proposed Tech Specs,Revising TS Surveillance Requirement Re ECCS Pump Casings & Discharge Piping High Points Outside of Containment ML20141K8991997-05-24024 May 1997 Proposed Tech Specs Revising TS Surveillance Requirement 4.5.2.b to Encompass non-operating ECCS Pumps & Discharge Piping Which Are Provided W/High Point Vent Valves ML20148D6861997-05-23023 May 1997 Proposed Tech Specs Revising TS Surveillance Requirement 4.5.2.b.1 for Unit 1 as It Relates to Requirement to Vent ECCS Pump Casings & Discharge Piping High Points Outside Containment ML20141K8931997-05-23023 May 1997 Proposed Tech Specs Revising TS Surveillance Requirement 4.5.2.b.1 for Unit 1 as It Relates to Requirement to Vent ECCS Pump Casings & Discharge Piping High Points Outside Containment ML20141K3381997-05-23023 May 1997 Proposed Tech Specs Requesting Enforcement Discretion from Compliance W/Ts 4.5.2.b.1 Requirements of Venting of Emergency Core Cooling Sys Pump Casings & Discharge Piping High Points Outside of Containment ML20141K0011997-05-21021 May 1997 Proposed Tech Specs Relocating Reactor Vessel Surveillance Program Capsule Withdrawal Schedules IAW GL 91-01 ML20148B6151997-05-0606 May 1997 Proposed Tech Specs,Revising TS 3/4.7.5, Ultimate Heat Sink & Associated Bases to Support SG Replacement & Incorporate Recent UHS Design Evaluations ML20196G0501997-04-25025 April 1997 Proposed Tech Specs Revising Primary Containment & Reactor Coolant Sys Volume Associated W/Unit 1 Steam Generator Replacement 1999-07-30
[Table view] Category:TECHNICAL SPECIFICATIONS & TEST REPORTS
MONTHYEARML20210J1751999-07-30030 July 1999 Marked-up TS Pages for Proposed Changes Re Upper Temp Limit for UHS ML20209B7411999-06-30030 June 1999 Proposed Tech Specs Section 3.8.5, DC Sources - Shutdown, Correcting LCO & Braidwood TS Section 3.8, Electrical Power Systems, Deleting Various References to At&T Batteries ML20211C3311999-04-30030 April 1999 Rev 2.0 to Generic ODCM for Dresden,Quad Cities,Zion, Lasalle,Byron & Braidwood ML20204H9781999-03-23023 March 1999 Proposed Tech Specs,Revising Sections 3.7.15,3.7.16,4.3.1 & 4.3.3 to Support Installation of New Boral high-density SFP Storage Racks at Byron & Braidwood Stations ML20204H4291999-03-22022 March 1999 Proposed Tech Specs 3.9.3,allowing Use of Gamma-Metrics post-accident Neutron Monitors to Provide Neutron Flux Info During Operational Mode 6 ML20202G9361999-01-30030 January 1999 Rev 1.4 to Chapter 10, Radioactive Effluent Treatment & Monitoring, Rev 1.6 to Chapter 11, Radiological Environ Program & Rev 1.6 to Chapter 12, Radioactive Effluent Technical Standards (Rets), for Odcm,Byron Annex ML20198N3471998-12-29029 December 1998 Proposed ITS Tables 3.3.1-1 & 3.3.2-1,revising Twelve Allowable Values ML20198N2041998-12-29029 December 1998 Revised Tech Specs Change,Page 3/4 3-54,providing Early Implementation of Containment Floor Drain Sump Water Level Instrumentation Requirements ML20198K5841998-12-23023 December 1998 Revised Tech Spec Pages 3/4 3-53,3/4 3-53a,6-27 & 6-27a,for Rv LI Sys ML20198A0811998-12-14014 December 1998 Proposed Rev T to Improved Tech Specs Section 3.4, Reactor Coolant Sys ML20196G6611998-11-30030 November 1998 Proposed Rev to Improved Tech Specs Section 3.1 ML20196B4101998-11-25025 November 1998 Proposed Tech Specs Facilitating Replacement of 125 Vdc At&T Batteries with New 125 Vdc C&D Batteries While in Mode 1-4 ML20155J2051998-11-0505 November 1998 Proposed TS Converting to Its,Rev R ML20155J0041998-10-30030 October 1998 Proposed Tech Specs Section 5.6.2, Fuel Storage Drainage, to Identify Sf Pool Level Sufficient to Ensure SRP Acceptance Criteria ML20154S5011998-10-18018 October 1998 Proposed Rev N to Improved TS Section 3.7 ML20154M5281998-10-15015 October 1998 Revisions K,O & P of 961213 ITS Submittal ML20154A8881998-10-0202 October 1998 Proposed Rev L to Improved Tech Specs Section 3.8 Closeout ML20153G4331998-09-25025 September 1998 Revs J & M to Tech Specs Sections 3.6 & 5.0,converting to Improved Tech Specs (Its),Final Closeout Package ML20153C0351998-08-31031 August 1998 Revs to ODCM for Plant,Including Rev 2 to Chapters 10 & 11, Rev 4 to Chapter 12 and Rev 3 to App F ML20238F8221998-08-25025 August 1998 Rev 2 to Braidwood Station Units 1 & 2 Second Interval ISI Program Plan ML20236Y5481998-08-0303 August 1998 Rev 1 to Braidwood Station Units 1 & 2 Second Interval ISI Program Plan ML20236W5851998-07-31031 July 1998 Proposed Rev G to Sections 3.1 & 3.2 of Improved Tech Specs ML20237B6391998-07-30030 July 1998 Proposed Rev H to Section 3.5 of Improved Tech Specs ML20237E9971998-07-21021 July 1998 Rev I to Proposed Improved Tss,Section 3.9 Re Final Closeout ML20237B7021998-07-0909 July 1998 Proposed Improved TS (ITS) Section 3.3 Issued as Result of Removing Generic Change Traveler TSTF-135,Rev E from ITS Submittal ML20236H6531998-07-0202 July 1998 Rev F to 961213 Improved TS Submittal,Containing Final Package Closeout for Improved TS Sections 1.0,2.0 & 3.0 ML20248M1491998-06-0101 June 1998 Proposed Tech Specs Bases Page B 3.8-58b,converting to Improved Tech Specs ML20248K7361998-05-31031 May 1998 Commonwealth Edison Bnps Unit 1 Cycle 9 Startup Rept ML20248C5511998-05-29029 May 1998 Proposed Tech Specs Bases Section 3/4.4.4, Relief Valves, Specifically Crediting Automatic Function of PORVs to Provide Mitigation for Inadvertent Operation of ECCS at Power Accident ML20217Q8521998-05-0101 May 1998 Rev 9 to Bzp 310-2, Nuclear Accident Reporting Sys Form (Primary Responsibility - Station Director). W/Notes & Comments ML20216D9431998-04-0909 April 1998 Modified Proposed TS Pages Re 980324 Request for Amends to Licenses NPF-37 & NPF-66 ML20216C1011998-03-26026 March 1998 Revs to ODCM for Braidwood,Including Rev 1.9 to Chapter 10 & Rev 3 to Chapter 12 ML20217E1891998-03-24024 March 1998 Proposed Tech Specs Surveillance Sections & Bases Allowing Util to Defer 10CFR50,App J,Type a Testing of Byron Unit 2 Containment Until Next Refuel Outage in 1999 ML20217B2681998-02-14014 February 1998 Proposed Rev D to ITS ML20217C3011998-01-31031 January 1998 Rev 0 to Inservice Testing Program Plan Pumps & Valves Braidwood Nuclear Generating Station,Units 1 & 2 ML20198L8131998-01-14014 January 1998 Proposed Tech Specs Pages Revising TS 3.4.8, Specific Activity, Figure 3.4-1,Table 4.4-4 & TS Bases 3.4.8 ML20198L8811998-01-14014 January 1998 Proposed Tech Specs Pages,Revising TS Section 3/4.8.2 & Bases,To Allow Replacement of 125 Volt Dc At&T Batteries W/New Charter Power Sys,Inc (C&D) Batteries ML20216H4321997-12-31031 December 1997 Revs to OCDM for Braidwood,Including Rev 1.8 to Chapter 10, Rev 1.9 to Chapter 11,rev 2 to Chapter 12 & Rev 2 to App F ML20199J7581997-12-31031 December 1997 Rev 1 to IST Plan Pumps & Valves Byron Nuclear Generating Station,Units 1 & 2 ML20198C3181997-12-30030 December 1997 Proposed Tech Specs 3.7.1.3 Re Condensate Storage Tank ML20203M5921997-12-17017 December 1997 Proposed Tech Specs,Rev C Changes Improved TSs 3.0,3.3,3.7, 3.8 & 5.0 as Result of Removing Generic Change Traveler TSTF-115 from Improved TS Submittal ML20203D0361997-12-0909 December 1997 Proposed Tech Specs Pages Correcting Errors Discovered in Current TS W/Regards to Total RCS Volume & Correction to Increase in RCS Volume Associated W/Unit 1 Replacement SGs Accounting for Hot Conditions ML20199A4751997-11-0707 November 1997 Proposed Tech Specs Pages Revising TS Surveillance Sections 4.6.1.1.c,4.6.1.2.a,4.6.1.2.c & Bases to Allow Performance of 10CFR50 App J,Type a Testing ML20216H8241997-10-31031 October 1997 Revs to OCDM for Byron Station,Including Rev 1.3 to Chapter 10,rev 1.5 to Chapters 11 & 12 & Rev 1.3 to App F ML20198M2621997-10-31031 October 1997 Revs to Offsite Dose Calculation Manual,Consisting of Rev 1.5 to Chapter 11 & Rev 1.5 to Chapter 12 ML20217K4461997-10-21021 October 1997 Proposed Tech Specs Re Boron Credit in SFP ML20198P1601997-10-20020 October 1997 Rev 1.5 to Odcm,Chapter 12 ML20202F4561997-10-10010 October 1997 Proposed Tech Specs,Deleting Lower Flow Rate Requirement Associated W/Nonaccessible Area Exhaust Filter Plenum & Fuel Handling Bldg Ventilation Sys ML20211D9421997-09-24024 September 1997 Proposed Tech Specs Revising Allowable Time Interval for Performing Turbine Throttle Valve & Turbine Valve SRs Requirements from Monthly to Quarterly ML20216H7011997-09-10010 September 1997 Revised Procedures,Including Rev 2 to Bwzp 2000-18, Post- Accident Sampling Sys (Primary Responsibility - Chemistry Director) & Rev 2 to Bwzp 2000-18A1, PASS Sample Collection Procedures 1999-07-30
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CONTAINMENT SYSTEMS
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SURVEILLANCE REQUIREMENTS (Continued)
- b. Performing tendon detensioning, inspections, and material tests on a previously stressed tendon from each group (dome, vertical, and hoop). A randomly selected tendon from each group shall be completely detensioned in order to identify broken or damaged wires and deter-mining that over the entire length of the removed wire or strand that:
- 1) The tendon wires or strands are free of corrosion, cracks, and d amag.e ,
- 2) There are no changes in the presence or physical appearance of the sheathing filler grease, and *
- 3) A minimum tensile strength of 240,000 psi (guaranteed ultimate strength of the tendon material) for at least three wire or strand samples (one from each end end one at mid-length) cut from each removed wire or strand. Failure of any one of the wire or strand samples to meet the minimum tensile strength test is evidence of abnormal degradation of the containment vessel structure.
- c. Performing tendon retensioning of those tendons detensioned for inspection to their observed Tift-off force with a tolerance limit of +6%. During retensioning of these tendons; the changes in load and elongation should be measured simultaneously at a minimum of three approximately equally spaced levels of force between zero and the seating force. If the elongation corresponding to a specific load differs by more than 5% from that recorded during installation, an investigation should be made to ensure that the difference is not related to wire failures or slip of wires in anchorages;
- d. Assuring the observed lift-off stresses adjusted to account for elastic losses exceed the average minimum design value given below:
Dome 133t e ksi Vertical 121ibb6 ksi .
Hoop 13340} ksi
- e. Verifying the OPERABILITY of the sheathing filler grease by assuring:
- 1) No voids in excess of 5% of the net duct volume,
- 2) Minimum grease coverage exists for the different parts of the anchorage system, and .
- 3) The chemical properties of the filler aaterial are within the tolerance limits as specified by the manufacturer.
BYRON - UNITS 1 & 2 3/a 6-9 G803140184 880002 PDR ADOCK 05000454 P DCD _
CONTAINMENT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)
- b. Performing tendon detensioning, inspections, and material tests on a previously stressed tendon from each group (dome, vertical, and hoop). A randomly selected tendon from each group shall be completely detensioned in order to identify broken or damaged wires and deter-mining that over the entire length of the removed wire or strand that:
- 1) The tendon wires or strands are free of corrosion, cracks, and damage,
- 2) There are no changes in the presence or physical appearance of the sheathing filler grease, and
- 3) A minimum tensile strength of 240,000 psi (guaranteed ultimate strength of the tendon material) for at least three wire or strand samples (one from each end and one at mid-length) cut from each removed wire or strand. Failure of any one of the wire or strand samples to meet the minimum tensile strength test is evidence of abnormal' degradation of the containment vessel structure.
- c. Performing tendon retensioning of those tendons detensioned for inspection to their observed lift-off force with a tolerance limit o f +6%. During retensioning of these tendons, the changes in load and elongation should be measured simultaneously at a minimum of three approximately equally spaced levels of force between zero and the seating force. If the elongation corresponding to a specific load differs by more than 5% from that recorded during installation, an investigation should be made to ensure that the difference is not related to wire failures or slip of wires in anchorages;
- d. Assuring the observed lift-off stresses adjusted to account for elastic losses exceed the average minimum design value given below:
Dome 13314+ ksi '
Vertical It.r) 444 ksi Hoop / g 440 ksi
- e. Verifying the OPERABILITY of the sheathing filler grease by assuring:
- 1) No voids in excess of 5% of the net duct volume,
- 2) Minimum grease coverage exists for the different parts of the anchorage system, and
- 3) The chemical properties of the filler material are within the tolerance limits as specified by the manufacturer.
BRAIDWOOD - UNITS 1 & 2 3/4 6-9
4 ATTACHMENT B DESCRIPTION AND SUP9tARY OF PROPOSED CHANGES The proposed changes involve Technical Specification 4.6.1.6.1.d for the Byron and Braidwood Stations.
Basis for Changes to Tendon Design Stress Values The design tendon stresses for Byron /Braidwood containments specified in the current Technical Specification can be reduced as follows:
Dome from 143 ksi to 133 ksi Vertical from 144 ksi to 127 ksi Hoop from 140 ksi to 133 ksi Original Desian Basis The containment tendon forces balance loads, in particular pressure, that put the containment shell in tension. The tendon force must be sufficient to balance the tension forces to keep the reinforcing steel within the allowable stresses.
Two load ccmbinations and load factors given in Table 3.8-3 of the PSAR which control the design of the tendon forces are:
For hoop and dome tendons: .
Abnormal: 1.5P a =Ta (LE) - D ,
For vertical tendon:
Abnormal / Severe Environmental: 1.25 (Pa + (OBE) + Ta (LE) - D where Pa = the design internal pressure of 50 psig Ta (LE) = liner expansion effect due to temperature difference between liner and concrete OBE = Operating Basis Earthquake D = Dead Load 1
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Basis for Revision The new design stress values were derived by taking into account the following refinements that had not been considered in the original design values.
- 1. Additional Tendon Forces @ P a Force in the tendons increase corresponding to the outward deflection of the wall when internal accident pressure (P a ) is applied, compatibility dictates that the tendons are extended by the outward deflection due to the pressure. Additional tendon forces of 1.73%,
1.75%, and 3.8% of the forces produced by Pa are accounted for dome, vertical and hoop tendons respectively. They are based on the deflections observed during the Structural Integrity Tests.
- 2. Reduction in Liner Expansion Force @ Pa The applied internal accident pressure, Pa , also extends the liner.
The liner is at a higher temperature than the concrete and when it tries to expand it puts the concrete in tension. The extension of the liner due to Pa relieves the liner expansion forces assumed in the original design for dome, vertical and hoop tendons, respectively, by 10%, 25%,
and 18%. The required tendon forces in the wall are consequently reduced.
- 3. Use of Refined Seismic Analysis The containment seismic forces used in the original tendon design were calculated assuming a maximum overturning moment obtained from a
. simplified seismic "stick model" was applied over the containment wall sections. The seismic forces can be reduced by 13% for the section at the basemat-wall junction when the refined DYNAX seismic model which utilizes a 3-dimensional analysis is used. This substantially reduces the force required in the vertical tendons.
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ATTACHMENT C EVALUATION OF SIGNIFICANT HAZARDS CONSIDERATIONS Commonwealth Edison has evaluated this proposed amendment and determined that it involves no significant hazards considerations.
According to 10 CFR 50.92(c), a proposed amendment to an operating license involves no significant hazards considerations if operation of the facility '
in accordance with the proposed amendment would not:
- 1) Involve a significant increase in the probability or consequences of an accident previously evaluated; or
- 2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or
- 3) Involve a significant reduction in a margin of safety.
The proposed amendment of Specification 4.6.1.6.1.d reduces the containment tendon design stresses to incorporate additional design margin not reflected in the values currently in the Technical Specifications. The design stresses provided in the Technical Specifications correspond to the average tendon stress after 40 years of losses. Losses occur due to relaxation in the tendon wires and shrinkage and creep in the concrete.
Most of these losses occurred in the first few years after the tendons were stressed (1980 to 1982 at Byron and Braidwood). Thus the predicted tendon force determined when performing the Technical Specification surveillances can approach the design force. The difference between the calculated tendon force and the design force is small enough that factors such as different methodologies for performing lift-offs at installation and at the in-service inspection and tolerances on the equipment can result in tendon forces at variance with technical specification valves. When these limits are not met, the Technical Specifications require that the containment integrity be restored, an engineering evaluation be performed and a special report be submitted to the Commission or that the station be shutdown.
The new design stress values were derived by taking into account such factors as additional tendon forces based on the deflections observed during the Structural Integrity Tests and reduction in the liner expansion force which consequently reduces the tendon forces in the containment wall.
Also the vertical tendon forces were reduced by the use of a refined DyNAX seismic model which uses a three-dimensional analysis. The proposed reduced design stresses will provide a larger margin between the expected tendon forces and the Technical Specification values.
The proposed amendment does not involve a significant increase Thein the probability or consequences of an accident previously evaluated.
changes do not alter the existing tendon stresses or the containment system. They merely incorporate new design stress values as determined by the Architect / Engineer based on refinements not included in the original design basis. The new design stress values meet the Byron and Braidwood PGAR acceptance criteria for use in monitoring containment prestressing.
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i The change does not add or modify any existing equipment, nor introduce a new mode of plant operation. The containment tendon lift-off stresses will continue to be The verified in accordance containment with system remains Technicalin its as-built Specification 4.6.1.6.1.d.
configuration and the design is in accordance with the Byron and Braidwood PSAR acceptance criteria. As such, the possibility of a new or different kind of accident from any accident previously evaluated is not created.
The proposed amendment does not involve a significant reduction in a margin of safety. The containraent structure and the existing tendon stresses remain unchanged. The revision establishes new tendon design stress values for monitoring the prestress. In addition, this ensures the containment maintains its integrity following an accident that generates an internal design pressure.
The new values were prepared in accordance with The new design the acceptance criteria in the Byron and Braidwood FSAR.
stress values were determined in accordance with accepted methodologies so the margin of safety is not impacted.
Therefore based on the above analysis, commonwealth Edison concludes that the proposed amendment to the Technical Specification does not involve significant hazard considerations. t 4301K l
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