PLA-6398, Request for Additional Information for the Review of the Susquehanna Steam Electric Station Units 1 and 2, License Renewal Application (LRA) Follow-Up to PLA-6398 Responses PLA-6442
| ML083300392 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 11/11/2008 |
| From: | Spence W PPL Corp, Susquehanna |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| PLA-6398, PLA-6442 | |
| Download: ML083300392 (18) | |
Text
A William H. Spence Executive Vice President and Chief Operating Officer/Chief Nuclear Officer Tel. 610.774.3683 Fax 610.774.5019 Whspence@pplweb.com PPL Corporation Two North Ninth Street Allentown, PA 18101-1 179 Tel. 610.774.5151 www.pplweb.com No 120@M U. S. Nuclear Regulatory Commission Document Control Desk Mail Stop OPI-17 Washington, DC 20555 SUSQUEHANNA STEAM ELECTRIC STATION REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE SUSQUEHANNA STEAM ELECTRIC STATION UNITS 1 AND 2, LICENSE RENEWAL APPLICATION (LRA)
FOLLOW-UP TO PLA-6398 RESPONSES PLA-6442 Docket Nos. 50-387 and 50-388
References:
"Application for Renewed Operating License Numbers NPF-14 and NPF-22,"
dated September 13, 2006.
"Request for Additional Information for the Review of the Susquehanna Steam Electric Station Units 1 and 2, License Renewal Application (LRA) Sections B.2.41, B.2.42, B.2.43, B.3.2, and 3.6," dated August 5, 2008.
In accordance with the requirements of 10 CFR 50, 51, and 54, PPL requested the renewal of the operating licenses for the Susquehanna Steam Electric Station (SSES)
Units 1 and 2 in Reference 1.
On October 10, 2008 a teleconference between PPL and NRC identified the need to provide the NRC with additional information and clarification to RAI responses contained in Reference 2.
The enclosure contains the additional information and clarification to the items discussed during the teleconference.
A new aging management program for certain fuseholders and a new License Renewal regulatory commitment are added to manage the aging of fuseholders, as described in the enclosure. There are no revisions to any other existing License Renewal commitments contained herein as a result of the attached response.
If you have any questions, please contact Mr. Duane L. Filchner at (610) 774-7819.
K1~k Document Control Desk PLA-6442 I declare, under penalty of perjury, that the foregoing is true and correct.
Executed on:
W. H. Spence
Enclosure:
PPL Response to Issues Discussed During October 10, 2008 Telecon Copy: NRC Region I Ms. E. H. Gettys, NRC Project Manager, License Renewal, Safety Mr. R. Janati, DEP/BRP Mr. F. W. Jaxheimer, NRC Sr. Resident Inspector Mr. A. L. Stuyvenberg, NRC Project Manager, License Renewal, Environmental
Enclosure to PLA-6442 PPL Response to Issues Discussed During October 10, 2008 Telecon
Enclosure to PLA-6442 Page 1 of 15 The following are provided as RAI supplemental responses based on an October 10, 2008 teleconference between NRC staff and PPL:
Supplement to RAI 3.6-1 Response (Fuseholders):
In response to RAI 3.6-1 in Reference 2, PPL provided justification for why removal of fuses annually for circuit testing would not result in fatigue of the fuse holder metallic clamp due to frequent manipulation. In the October 10, 2008 teleconference, the Staff stated that annual removal of a fuse from a fuse holder constitutes frequent manipulation which requires a Fuse Holders AMP.
PPL Response:
The SSES LRA is revised as follows to identify a Fuse Holders AMP for managing potential aging effects of fuse holder metallic clamps for certain fuse holders within the scope of license renewal. The fuseholders in the scope of this program are those located in enclosures that do not contain active components and whose fuses are scheduled for removal once every 12 months, or more frequently.
3.6.2.1.1 Non-EQ Insulated Cables and Connections LRA Section 3.6.2.1.1 (LRA page 3.6-3) is revised by addition (bold italics) as follows:
Aging Effects Requiring Management Based on analysis of the 60-year service limiting environments for the insulating materials, aging effects were identified for some non-EQ insulated cables and connections. Certain non-EQ, inaccessible medium-voltage cables that are exposed to wetting also have aging effects associated with the moisture and voltage stress involved.
The aging effects requiring management that are assumed for all the Non-EQ Cables and Connections exposed to adverse localized environments are the following:
" Reduced Insulation Resistance
" Electrical Failure (breakdown of insulation)
NUREG-1801,Section XI.E6, addresses the metallic parts of electrical cable connections (such as splices, lugs, connectors, and terminal blocks), and also highlights the following aging stressors: thermal cycling, ohmic heating, electrical transients, vibration, chemical contamination, corrosion, and oxidation.
Based on the evaluation of the stressors identified in NUREG-1801,Section XI.E6, and the operating and service conditions of the metallic parts of the electrical cable connections at SSES, there are no aging effects requiring management identified for
Enclosure to PLA-6442 Page 2 of 15 SSES. However, to provide reasonable assurance that the function of the metallic parts of the electrical cable connections is maintained through the period of extended operation, SSES will implement an aging management program to follow the recommendation of NUREG-1801,Section XI.E6.
NUREG-1801,Section XI.E5, addresses the metallic clamps offuse holders located outside of active devices, and also highlights the following aging stressors: fatigue, mechanical stress, vibration, chemical contamination, and corrosion.
Based on the evaluation of the stressors identified in NUREG-1801,Section XI.E5, and the operating and service conditions of the SSES fuse holder metallic clamps located in enclosures that do not contain active components, there are no aging effects requiring management identified for SSES. However, because certain fuses are removed and reinserted approximately once every 12 months for circuit testing, SSES will implement an aging management program to follow the recommendation of NUREG-1801,Section XI.E5 to provide reasonable assurance that the aging effect of increased connection resistance due to fatigue of the fuse holder clamps located in enclosures that do not contain active components is not occurring and the function of the fuse holders will be maintained during the period of extended operation.
Aging Management Programs The following aging management programs manage the aging effects for the Non-EQ Cables and Connections components:
" Non-EQ Electrical Cables and Connections Visual Inspection Program
" Non-EQ Cables and Connections Used in Low-Current Instrumentation Circuits Program
" Non-EQ Inaccessible Medium-Voltage Cables Program
" Non-EQ Electrical Cable Connections Program
" Fuse Holders Program 3.6.2.3 Aging Management Review Results Not Consistent with NUREG-1801 3.6.2.3.1 Fuse Holders (Not Part of a Larger Assembly) - Metallic Clamp LRA Section 3.6.2.3.1 (LRA page 3.6-8) is revised by addition (bold italics) and deletion (stri4kethfough) as follows:
Twenty fuse boxes (containing only fuses and terminal blocks) were identified within the license renewal scope for SSES. Sixteen contain power and control fuses in the plant
Enclosure to PLA-6442 Page 3 of 15 direct current (DC) power systems and four contain 6-amp fuses associated with the control room emergency lighting system. Of these twenty, none contain fuses that are pulled from their metallic clamps more than once per year. An engineering evaluation concluded that Therefor, none of these specified fuse holders has a metallic clamp that will exhibit the aging mechanisms/ effects of fatigue and/or frequent manipulation listed in NUREG-1801, Item VI.A-8. However, to ensure the aging effect of increased connection resistance due to fatigue of the fuse holder clamps is not occurring, SSES will implement a Fuse Holders Program consistent with the recommendations of NUREG-1801,Section XI.E5 for the specified population. The other aging mechanisms/ effects detailed in NUREG-1801, Item VI.A-8 (ohmic heating, thermal cycling, electrical transients, vibration, chemical contamination, corrosion, and oxidation) are addressed in the following paragraphs.
The fuse holders are located in metallic electrical boxes (terminal boxes) which have covers that protect the interior of the box from the environment. The boxes are not exposed to weather (they are located indoors at SSES); they are not exposed to chemical contamination or spills (and such occurrences would be event-driven situations in any case); they are not exposed to mechanical stresses inside the boxes; and (due to the SSES location in rural PA) they are not operated in an environment of industrial pollution or salt deposition. Therefore, chemical contamination, corrosion, and oxidation are not applicable aging effects for the metallic clamps of the fuse holders within the license renewal scope at SSES.
With respect to electrical transients and ohmic heating, these fuses are not heavily loaded and do not experience frequent electrical and thermal cycling. The power fuses with bolted connections use Belleville washers to maintain good electrical contact in the event of any differential thermal expansion. In addition, since the power fuses are removed once every 4 to 6 years during battery surveillances, the bolted connections are not subject to loosening from long-term age related degradation. With respect to vibration, it is an induced aging mechanism (from equipment such as compressors, pumps, fans, etc.).
Because the electrical boxes are mounted on walls, vibration is not an applicable aging mechanism. Wear and fatigue for the metallic clamp are caused by repeated removal and insertion of fuses. By design, these fuses are not removed more than once per year; therefore, fatigue due to frequent manipulation does not apply. Therefore, electrical transients, ohmic heating, vibration, and fatigue are not applicable aging mechanism/effects for the metallic clamps of the fuse holders within the license renewal scope at SSES.
Enclosure to PLA-6442 Page 4 of 15
> LRA Table 3.6.1 (LRA page 3.6-11) is revised by addition (bold italics) as follows:
Table 3.6.1 Summary of Aging Management Programs for Electrical and I&C Components Evaluated in Chapter VI of the GALL Report Further Item Aging Aging Management Number Component / Commodity Effect/Mechanism Programs Evaluation Discussion Recommended 3.6.1-06 Fuse Holders (Not Part of a Fatigue due to ohmic Fuse Holders No The aging effects detailed in Larger Assembly):
heating, thermal NUREG-l1801 are not applicable cycling, electrical for this item at SSES. None of Fuse Holders - metallic clamp transients, frequent the fuse holders that are within manipulation, the scope of license renewal vibration, chemical contain fuses that are frequently contamination, manipulated, and inspection of a corrosion, and sample of the in-scope fuse oxidation boxes showed that conditions are clean and dry, with no corrosion or moisture intrusion. However, to ensure the aging effect of increased connection resistance due to fatigue of the fuse holder clamps is not occurring, SSES will implement a Fuse Holders Program consistent with the recommendations of NUREG-1801,Section XI.E5. Additional information for this item is presented in Section 3.6.2.3.1.
Enclosure to PLA-6442 Page 5 of 15 The following LRA Table 3.6.2-1 line item (LRA page 3.6-18) and Plant Specific Notes line item (LRA page 3.6-22) are revised by addition (bold italics) and deletion (stri4kethf--ogh):
Table 3.6.2-1 Aging Management Review Results - Electrical and I&C Components I I I
NUREG-Component /
Intended Aging Effect Aging 1801 Commodit Fntin Material Environment Requiring Management Volume 2 Table 1 Item Notes Commodity Function Management Programs Item Fuse Holders:
pFuse HoldersH Conduct Copper Indoor Air None Identified VI.A-8 3.6.1-6 0
Metallic Electricity Alloy N
0603 Clamp Plant-Specific Notes:
A total of 145 fuse boxes (containing only fuses and/or terminal blocks) were identified for SSES. Of these 145 boxes, 20 contain fuses that are in the scope of license renewal. However, none of these boxes contain fuses that are pulled from their metallic clamps more than once per year.
Therfe4re, An engineering evaluation concluded that none of these fuse holders has a metallic clamp that will exhibit the aging 0603 mechanisms/effects of fatigue and/or frequent manipulation listed in GALL Item VI.A-8. However, to ensure the aging effect of increased connection resistance due to fatigue of the fuse holder clamps is not occurring, SSES will implement a Fuse Holders Program consistent with the recommendations of NUREG-1801,Section XI.E5 as detailed in Section 3.6.2.3.1. The other aging mechanisms/effects detailed in GALL VI.A-8 (ohmic heating, thermal cycling, electrical transients, vibration, chemical contamination, corrosion, and oxidation) are addressed in Section 3.6.2.3.1. Inspection of a sample of the fuse boxes showed that conditions are clean and dry, with no corrosion or moisture intrusion.
Enclosure to PLA-6442 Page 6 of 15 A.1.2 - Aging Management Programs and Activities The following program description is added to the listing of aging management programs and activities in Appendix A of the LRA (page A-21).
A.1.2.51 Fuse Holders Program The Fuse Holders Program is a new aging management program that manages increased connection resistance due to fatigue of fuse holder clamps. The program provides for periodic inspection of fuse holder clamps within the scope of license renewal that are not in enclosures containing active components and whose fuses are scheduled for removal once every 12 months, or more frequently.
The Fuse Holders Program is a condition monitoring program consisting of inspections performed on a 10-year frequency to detect aging and age-related degradation.
The Fuse Holders Program is a new aging management program that will be implemented prior to the period of extended operation.
Enclosure to PLA-6442 Page 7 of 15 A.1.4 License Renewal Commitment List The following new commitment is added to the listing of license renewal commitments in Appendix A of the LRA (page A-55).
Table A-1 SSES License Renewal Commitments FSAR Enhancement Supplement or Item Number Commitment location Location Implementation (LRA App. A)
Schedule
- 59) Fuse Holders Program is new.
A.1.2.51 Prior to the period Program The Fuse Holders Program is credited with identifying increased of extended connection resistance between the fuse holder metallic clamp and fuse due operation.
to fatigue of the metallic clamp. The program provides for periodic inspection offuse holder clamps within the scope of license renewal that are not in enclosures containing active components and whose fuses are scheduled for removal once every 12 months, or more frequently.
Enclosure to PLA-6442 Page 8 of 15 B.2 AGING MANAGEMENT PROGRAMS
)
The following line item in Table B-1 (on LRA page B-12) is revised by addition (bold italics) and deletion (str4kethr-e'gh) as follows:
Table B-1 Correlation of NUREG-1801 and SSES Aging Management Programs Number NUREG-1801 Program Corresponding SSES Program XI.E5 Fuse Holders adt e,*d..
ad f agn
.mngment.
Fuse Holders Program See Section B.2.50 The following program is added to the listing of aging management programs in Table B-2 (on LRA page B-15).
Table B-2 Consistency of SSES Aging Management Programs with NUREG-1801 New /
Consistent Exceptions Plant-Enhancement Program Name Existing with NUREG-to NUREG-Specific Required 1801 1801 Fuse Holders New Yes Program
Enclosure to PLA-6442 Page 9 of 15 The following program description/evaluation is added to Section B.2 of the LRA.
B.2.50 Fuse Holders Program Program Description The purpose of the Fuse Holders Program is to manage increased connection resistance due to fatigue of the fuse holder metallic clamp for fuse holders in the scope of the program. This program will be used to ensure that the metallic clamps of the fuse holders are not loosening due to removal and reinsertion of fuses.
The Fuse Holders Program is a condition monitoring program consisting of inspections to detect age-related degradation.
NUREG-1801 Consistency The SSES Fuse Holders Program is a new program that will be consistent with the 10 elements of an effective aging management program as described in NUREG-1801,Section XI.E5, "Fuse Holders," with an exception.
Exceptions to NUREG-1801 Program Element Affected:
- Parameters Monitored/Inspected -
Monitoring only includes the mechanical fatigue of the metallic clamp portion of the fuse holder caused by removal and insertion of the fuse. None of the other aging effects/mechanisms identified in this GALL program element are applicable.
Aging Management Program Elements The results of an evaluation of each program element are provided below.
Scope of Program The metallic clamp portion of fuse holders located outside of enclosures containing active components, and susceptible to the identified aging effects, are included in the scope of this program. Fuse holders located in enclosures that also house active components are excluded from the scope of this program. Fuse holders in the scope of this program are those whose fuses are scheduled for removal once every 12 months, or more frequently. The only SSES fuse holders that meet these criteria are those associated with the plant control room emergency
Enclosure to PLA-6442 Page 10 of 15 lighting circuits. Four fuse boxes located in the plant control room contain fuses that are scheduled for removal once every 12 months for control room emergency lighting circuit testing. The fuse holders associated with these fuses are those in the scope of this program.
" Preventive Actions No actions are taken as part of this program to prevent or mitigate aging degradation.
" Parameters Monitored or Inspected This program will focus on the metallic clamp portion of the fuse holder. The fuse holders will be inspected to identify increased connection resistance between the fuse and the fuse holder metallic clamp due to mechanical fatigue that could result from removal and insertion of the fuse.
" Detection of Aging Effects All of the fuse holders in the scope of this program will be tested using thermography at least once every 10 years. Thermography is a proven test for detecting increased connection resistance. A 10-year testing interval is adequate to preclude failures of the fuse holders because experience has shown that the subject aging degradation is a slow process. This will provide two data points during a 20-year period, which can be used to characterize the degradation rate.
The first tests for license renewal will be completed before the period of extended operation.
" Monitoring and Trending Trending actions are not included as part of this program.
" Acceptance Criteria The acceptance criteria will be based on the acceptance criteria already used for the thermography process at SSES.
- Corrective Actions This element is common to SSES programs and activities that are credited with aging management during the period of extended operation and is discussed in Section B. 1.3.
" Confirmation Process This element is common to SSES programs and activities that are credited with aging management during the period of extended operation and is discussed in Section B. 1.3.
Enclosure to PLA-6442 Page 11 of 15
" Administrative Controls This element is common to SSES programs and activities that are credited with aging management during the period of extended operation and is discussed in Section B. 1.3.
" Operating Experience The Fuse Holders Program is a new program for which there is no SSES-specific operating experience. However, the following are examples of Susquehanna operating experience that demonstrate that the aging effect of interest in this AMP (i.e., increased connection resistance due to loosening of fuse holder metallic clamps) can be, and has been, successfully detected at SSES.
During routine preventive maintenance activities in 2005, a fuse holder in a Unit 1 feedwater control panel was identified as being slightly warmer than other fuse holders in the same location due to loosening of the fuse holder metallic clamps.
The fuse holder was replaced, and post-maintenance testing, using thermography, confirmed the condition was corrected. In 2004, a fuse holder in a Unit 2 reactor building chiller control panel was identified as being slightly warmer than other fuse holders in the same location due to loosening of the fuse holder metallic clamps. The fuse holder was replaced, and post-maintenance testing, using thermography, confirmed the condition was corrected. The condition was detected prior to loss of intended function in both of these cases.
Both of these operating experience examples are for fuse holders in enclosures with active components and therefore not in the scope of this AMP. However, the fact that loosening of the metallic clamp portion of fuse holders has been detected using thermography at SSES and corrective action was taken supports the conclusion that this AMP will provide reasonable assurance that the aging effects will be managed such that the fuse holders within the scope of this program will continue to perform their intended functions consistent with the current licensing basis for the period of extended operation.
Required Enhancements None.
Conclusion The Fuse Holders Program will manage the aging of the metallic clamp portion of the fuse holders. The Fuse Holders Program will provide reasonable assurance that aging effects will be managed such that the fuse holders within the scope of this program will continue to perform their intended function consistent with the current licensing basis for the period of extended operation.
Enclosure to PLA-6442 Page 12 of 15 Clarification of RAI 3.6-2 Response (Transmission Conductor Loading):
The NRC Staff has requested clarification of PPL's response to RAI 3.6-2 in Reference 2 to explain how the transmission line design meets the National Electric Safety Code (NESC) and to correct a mathematical error in the percent margin for ultimate strength calculation for the transmission conductors.
PPL Response:
The original RAI is included below for clarity, followed by PPL's revised response. The "Revised PPL Response" is a complete replacement for the response previously provided to RAI 3.6-2 in Reference 2. The response has been revised to clarify how PPL's design relates to the NESC requirements and to correct an error in the calculation of percent margin.
Original RAI 3.6-2:
Please explain how the tests were conducted at Ontario Hydroelectric and explain in detail how SSES transmission conductors are bounded by the tests conducted at Ontario Hydroelectric and will have adequate margin for 60 years.
Revised PPL Response:
The papers describing Ontario Hydro's tests and results are available from the Institute of Electrical and Electronics Engineers (IEEE). They were published as Part I and Part II of "Aged ACSR Conductors" in the "IEEE Transactions on Power Delivery," Vol. 7, No. 2, April 1992, pages 581-595. The relevant conclusion of the papers for SSES is "For planning purposes a mean useful life of 70 years is considered valid for existing conductors."
The tests for Ontario Hydro were conducted in the field and in the laboratory. A non-destructive corrosion detector was modified for live line measurement of the loss of galvanizing from the steel cores of the ACSR conductors. The field measurements were performed using a motorized overhead line corrosion detector that traveled along the transmission line. Samples of the conductors tested in the field also were examined in the lab, through tests of fatigue, tensile strength, torsional ductility, and electrical performance. The fatigue and tensile strength testing involved the use of a dynamometer and an electromagnetic shaker, with the conductor strung across a suspension assembly.
Enclosure to PLA-6442 Page 13 of 15 SSES Conductor Design:
The National Electric Safety Code (NESC), (under Rule 261H1 a of the 2007 NESC) requires that the maximum tension of installed conductors shall not be more than 60% of their rated breaking strength for the NESC district design load. The NESC "Heavy" district is the one applicable to the SSES transmission lines. NESC "Heavy" design conditions are the simultaneous consideration of 1/2 inch of radial ice, a 4 psf wind, and 0 deg F temperature. To improve reliability, PPL design criteria for 230kV transmission lines are more conservative than NESC "Heavy." Although these conditions are not expected to occur, PPL uses design criteria of 1" radial ice with a simultaneous 8 psf wind and 0 deg F temperature.
Conductor loading requirements are reviewed below for the two SSES offsite power supply circuits which are identified as the "Startup Transformer #10 230kV Tap" and the "230kV/500kV Yard Tie," which operates at 230kV.
Both of these lines utilize 1590 kcmil Lapwing 45/7 ACSR conductors. 1590 describes the cross-sectional area of the conductor in kcmils (1 kcmil=1000 circular mils, and one circular mil=the cross-sectional area of a circle 1 mil in diameter.) Lapwing is the common industry name for this conductor. The 45/7 means the conductor has 45 outer strands of aluminum conductor around a two-layer core consisting of 7 strands of galvanized steel wire. The "ACSR" means "aluminum conductor steel reinforced." The ultimate strength (rated breaking strength) of Lapwing is 42,200 pounds.
Using the PPL conservative design criteria, the maximum design tension for the conductors in the Startup Transformer #10 Tap is 21,537 pounds. To put these loadings in perspective, the PPL design is compared to the NESC "Heavy" requirements. Based on a simulation using an industry standard sag-tension computer program, the design maximum tension of 21,537 pounds under the PPL criteria of 1" radial ice simultaneously with an 8 psf wind and 0 deg F temperature corresponds to an NESC "Heavy" design maximum tension of 16,195 pounds. The 16,195 pound maximum tension is 38% of rated breaking strength under initial (newly installed conductor) conditions. Therefore, the NESC criteria are met.
Based on the NESC "Heavy" equivalent design maximum tension of 16,195 pounds for the Startup Transformer #10 230kV Tap conductors, the difference between the design maximum conductor load of 16,195 pounds and the ultimate conductor strength is 26,005 pounds, which produces a margin for ultimate strength of 62% [26,005 / 42,200 = 62%].
Conductor Aging Evaluation:
The Ontario Hydro study showed a 30% loss of composite conductor strength in the typical 70 year-old conductor. In the case of the Lapwing transmission conductors, a 30% loss of ultimate strength equates to an eventual conductor strength of 33,085 pounds
Enclosure to PLA-6442 Page 14 of 15 for the Startup Transformer #10 230kV Tap (1.12 x 42,200 x 0.7). As noted by Ontario Hydro, "new conductors show an average strength of 112% of rated tensile strength."
Based on the NESC "Heavy" equivalent design maximum tension of 16,195 pounds for the Startup Transformer #10 230kV Tap conductors, the difference between the design maximum conductor load of 16,195 pounds and the eventual conductor strength of 33,085 is 16,890 pounds, which produces a margin for ultimate strength of 51%
[16,890 / 33,085 = 51%].
The 230 kV / 500 kV Yard Tie line has a design maximum conductor tension of 16,000 pounds, and, thus, an even greater margin. Both transmission lines exceed the design requirements set forth by the NESC. Therefore, the expected margin at 70 years of age is adequate for these installed transmission conductors at SSES.
Transmission conductor samples tested in the Ontario Hydro Test included samples with 45/7 stranding and are representative of the installed conductors at SSES, so the conclusions from the Ontario Hydroelectric Test Report for the remaining strength after 70 years of installation are both conservative and valid for SSES. Therefore, loss of conductor strength due to corrosion of the transmission conductors is not an aging effect requiring management for the period of extended operation.
Clarification of B.2.41-2 (Localized Environment Temp and Rad Dose Values):
The Staff requested identification of temperature and radiation dose values that will be used to identify an adverse localized environment, to supplement the information provided in response to RAI B.2.41-2 in Reference 2.
PPL Response:
As described in PPL's response to RAI B.2.41-2 in Reference 2, a number of information sources will be used in conjunction with plant walkdowns to identify adverse localized environments. Specific temperature and radiation dose parameters that establish the threshold for determination of an adverse localized environment depend on the properties of the installed insulating material.
The aging management review process for the non-EQ electrical cables and connections identified 60-year service limiting environments for the insulating materials used at SSES. Age-related degradation of the organic insulating material is not expected below these 60-year service limiting conditions. The 60-year service limiting temperature and radiation dose values for insulating materials installed in a particular area of the plant are used as the threshold for identification of adverse localized environments. Any plant environment that exceeds the 60-year service limiting values will be evaluated as a potentially adverse localized environment. The most restrictive 60-year service limiting
Enclosure to PLA-6442 Page 15 of 15 temperature for electrical insulating materials in use at SSES is 112TF for Polyvinyl Chloride (PVC). The most restrictive 60-year service limiting radiation dose for electrical insulating materials in use at SSES is 5 x 104 rads for Fluorinated Ethylene Propylene (FEP). These values will be used as the thresholds for evaluation to identify adverse localized environments.