CPSES-200402319, Response to NRC Request for Additional Information 2RF06 and 2RF07 Steam Generator Reports
| ML042930638 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 10/14/2004 |
| From: | Blevins M, Madden F TXU Generation Co, LP, TXU Power |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| CPSES-200402319, TXX-04183 | |
| Download: ML042930638 (15) | |
Text
A TXU "49 Power TXU Power Mike Blevins Ref: 10CFR50.55a Comanche Peak Steam Senior Vice President &
Electric Station Chief Nuclear Officer P. O. Box 1002 (E01)
Glen Rose, TX 76043 Tel: 254 897 5209 Fax: 254 897 6652 mike.blevins~txu.com CPSES-200402319 Log # TXX-04183 October 14, 2004 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
UNIT 2 - DOCKET NO. 50-446 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION RE: 2RF06 AND 2RF07 STEAM GENERATOR REPORTS Gentlemen:
By means of an e-mail dated August 9, 2004, the NRC provided a request for additional information (RAI) necessary to complete their review of the Unit 2 Steam Generator (SG) tube inservice inspection (ISI) reports submitted by TXU Generation Company LP (TXU Power) subsequent to refueling outages 2RF06 and 2RF07. During a conference call on October 4, 2004, TXU Power and NRC staff discussed preliminary and clarifying information related to this RAI. The final questions, and TXU Power's answers to these questions, are attached to this letter.
Should you have any questions, please contact Mr. Bob Kidwell at (254) 897-5310.
This communication contains no new or revised commitments.
C)4,-7 A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Comanche Peak
- Diablo Canyon
- Palo Verde
- South Texas Project
- Wolf Creek
TXX-041 83 Page 2 of 2 Sincerely, TXU Generation Company LP By: TXU Generation Management Company LLC Its General Partner Mike Blevins By:, 9/ 2'?A Fred W. Madden Director, Regulatory Affairs RJK Attachment c - B. S. Mallett, Region IV W. D. Johnson, Region IV M. C. Thadani, NRR Resident Inspectors, CPSES
Attachment to TXX-04183 Response to NRC Request for Additional Information
Attachment to TXX-04183 Page 2 of 13 Ouestion:
- 1. Of the eight tubes plugged during the 2RF06 outage due to the presence ofsingle volumetric indication (SVI), two of the tubes (SG2-7-15 and SG2-24-37) displayed SVIs within a hot-leg tube supportplate (TSP) and one tube (SG3-6-80) displayedan SVI in thefreespan region between two hot-leg TSPs. The remainingfive tubes (SG2-43-32, SG2-36-59, SG3-3 7-55, SG3-38-55, and SG3-38-56) displayedSVIs just above the hot-leg top-of-tutbesheet (HTS) surface. 7he percent throughwall SVIpenetration depth was not given for any ofthese indications.
- a. Ifyou were unable to reliably determine the SVIpenetration depth, discuss how you were able to evaluate the integrity of these tubes.
CPSES Response to 1.a:
All eight SVI indications were phase-depth sized using a calibration standard based on an ASME 0.0625-inch diameter flat bottom hole of 20%, 40%, 60%,
80% and 100% through wall depths. This approach has been demonstrated to provide good sizing performance across a wide range of simulated wear scar morphologies. Seven of the eight indications relied on this sizing technique using a rotating pancake coil with only the indication in tube R6, C80 using the +Point coil. Bobbin coil identified a possible loose part in tube R6, C80 at the u-bend apex. This lead to a special interest + Point coil test that confirmed a possible loose part. The resulting throughwall maximum depths are shown in the following table. Additionally, all eight identified tubes were evaluated for foreign object wear indications against the tube integrity performance criterion with regard to structural and leakage integrity. This assessment is documented in WPT-16312, Foreign Object Wear Indications at Comanche Peak Unit 2 RF06 Outage, dated 4/24/02. Condition monitoring evaluation confirmed that all indications satisfied the performance criteria of NEI 97-06.
SG Tube SVI Location RPC Depth Estimate 2 R7 C15 HIO 14% TW 2 R24 C37 H1 (FDB) 28% TW 2 R36 C59 TTS (HL) 9% TW 2 R43 C32 TTS (HL) 28% TW 3 R6 C80 U-Bend Apex 46% TW 3 R37 C55 TTS (HL) 44% TW 3 R38 C55 TTS (HL) 43% TW 3 R38 C56 TTS (HL) 26% TW
Attachment to TXX-04183 Page 3 of 13 Ouestion:
L.b. Discuss whether any of these SVIs were presentduringprevious inspections and whether any growth had occurred. If any of these SVIs were detected duringprevious inspections, discuss whether these SVIs have changed with time.
CPSES Response to 1.b:
SG 2 and SG 3 were not inspected in 2RF05 and there is no report of these indications in the 2RF04 or 2RF03 inspection data.
Ouestion:
J.c. Provide the reasonfor plugging each of the eight tubes with SMIs, including the causefor each SVI (e.g., wear, intergranularattack, possible loose part, wear, etc.).
CPSES Response to 1.c:
The table below highlights the cause for the SVI and the basis for plugging the respective tube. Recognizing that sizing techniques are not qualified for loose parts all tubes were conservatively plugged. In some cases the estimated percent through wall exceeded the Technical Specification repair limit and these tubes were likewise plugged.
SG Tube SVI Mechanism Repair Basis 2 R7 C15 Possible loose part Conservatively plugged 2 R24 C37 Possible loose part Conservatively plugged 2 R36 C59 Foreign object Plugged/Stabilized since FO was not retrieved 2 R43 C32 Possible loose part Conservatively plugged 3 R6 C80 Possible loose part Exceeded Tech Spec repair limit 3 R37 C55 Possible loose part Exceeded Tech Spec repair limit 3 R38 C55 Possible loose part Exceeded Tech Spec repair limit 3 R38 C56 Possible loose part Conservatively plugged
Attachment to TXX-04 183 Page 4 of 13 Ouestion:
- 2. During the 2RF06 outage, three tubes (SG3-12-30, SG3-8-33, and SG3-9-33) with indicationsdenoted as "PCT" were plugged, accordingto the table in the June 5, 2002, report. TAe indications of interestin these three tubes were less than 11%
throughwall. The indications were located nearthe top of cold-leg tube supportplate C6.
2.a. Discuss whether any ofthese indicationswere present duringprevious inspections. If any of these indicationswere detected duringprevious inspections, discuss whether these indications have changed with time.
CPSES Response to 2.a:
The three tubes in SG 3 identified as exhibiting preheater baffle plate wear indications (R12C30, R8C33, R9C33) were not inspected at 2RF04 and there is no report of these indications in the 2RF03 data. However, in the 2RF05 outage (SG1 and SG 4 inspection only) two tubes were reported with tube-baffle plate wear. The maximum reported depth was 6%TW. Both indications were reported in the 2RF04 data and growth for these 2 indications was 2% and 3%.
Ouestion:
2.b. Provide the reasonfor plugging each of the three tubes, including the cause for each PCT indication (e.g., axial ODSCC, intergranularattack, etc.).
Discuss whether denting was associatedwith these PCT indications.
CPSES Response to 2.b:
The volumetric indications of R12C30 (11%TW), R8C33 (5%TW) and R9C33 (6%TW) located at the upper edge of C6 in SG 3 are believed to be related to wear with the baffle plate. These tubes were conservatively plugged in support of the philosophy of skipping outages (i.e., indications remaining in service for two cycles). There were no dent indications at any of these locations.
Attachment to TXX-04183 Page 5 of 13 question:
- 3. Duringthe 2RF06 and 2RF07 outages, discuss whether any inspections (e.g., eddy current and/orvisual)for loose parts were conducted. If loose partswere detected, provide the results of these inspections. If visual inspections twere not performed pursuantto any potential loosepartsignals and/or the part-wasnot removed, discuss what analyses wereperformed to ensure these potential loose parts do not compromise tube integrityfor the periodof time between inspections.
CPSES Response to 3:
A secondary side FOSAR inspection of all four SGs was performed during 2RF06 and 2RF07. Additionally, EC inspections of SG 2 and SG 3 (2RF06) and SG 1 and SG 4 (2RF07) for detection of possible loose parts were also conducted. These inspections identified a number of foreign objects that were removed where possible.
The tables that follow present the results of the respective inspections for all SGs reported from both EC and FOSAR. For 2RF06 the associated tubes, where loose parts could not be removed from the SGs, were plugged. Likewise for 2RF07, an evaluation (WPT-16497, Evaluation of Foreign Objects During the Fall 2003 Outage) of the loose parts that could not be removed from the SGs was performed. The evaluation demonstrates that it is acceptable to operate for up to two cycles with these objects in the SGs, whereupon a reassessment of the conditions would be necessary to justify continued operations.
Also note that a total of eight tubes were reported with foreign object wear in the 2RF06 inspection of SG 2 and SG 3 (these were discussed in detail in response to Question 1) and no tube wear due to loose parts was reported in the 2RF07 ECT inspection of SG 1 and SG 4.
Attachment to TXX-04183 Page 6 of 13 Summary of Foreign Object/Loose Parts Identified During 2RF06 3G Leg Roiv/Col Elev. First Found Shape Confirmed Resolution Removed By By F CL Annulus UTS Video sludge rock Visual Retrieved by Brooks Yes C45 inspection 0.25"xO.50" on 4/15/2002 1 CL Annulus TIS Video sludge rock Visual Retrieved by Brooks Yes C45 inspection 0.125"xO.250" on 4/15/2002 F CL R13C57 UTS Video Weld slag Visual Retrieved by Brooks Yes inspection 0.750"xO.375"xO.250" on 4/16/2002 F CL R13C57 UTS Video Weld slag Visual Retrieved by Brooks Yes inspection 0.50"xO.25"xO.25" on 4/16/2002 2 HL R36C52, TITS +Point Egg shaped weld slag Video Retrieved during Yes R36C53, inspection sludge lance on R38C53 4/13/2002 2 HL R30C56 TS +Point N/A N/A Nothing found N/A 2 HL R35C59, TS +Point Sludge rock Video Location precluded No R36C59 inspection retrieval. Attempted to inspect 3 times 2 CL R8C58 B Video Sludge rock Visual Retrieved by Brooks Yes inspection 0.718"xO.468"xO.343" on 4/13/2002 2 CL R8C58 B Video Wire mesh Visual Retrieved by Brooks Yes inspection 0.406"xO.53 1"xO.0 15" _ 4/13/2002 2 CL R23C69 B Video Sludge rock Visual Retrieved by Brooks Yes inspection 0.78 l"x0.406"x0.343" 4/13/2002 2 CL R23C56 B Video Weld slag Visual Retrieved by Brooks Yes inspection 0.486"xO.78 I"xO.343" 4/13/2002 2 CL R22C56 B Video Sludge rock Visual Retrieved by Brooks Yes inspection 0.718"xO.53 I"xO.343" 4/13/2002 2 CL R23C69 B Video Weld slag Visual Retrieved by Brooks Yes inspection .531 "xO.218"xO.2.18" 4/13/2002 2 CL R8C56 B Video Weld slag Visual Retrieved by Brooks Yes inspection 0.406"xO.406"xO.234" 4/13/2002 2 CL R1C56 B Video Flat sludge rock Visual Retrieved by Brooks Yes inspection 0.406"xO.593"xO.218" 4113/2002 2 HL R24C37 A +Point Weld slag Visual Retrieved by Brooks Yes 0.656"xO.593"xO.156" 4/13/2002 2 CL R20C56, B +Point Wedge Visual Detected by EC as a Yes R20C57 4"x2"xl" Baffle Support Signal (BSS)
Removed by Brooks on 4/14/2002
Attachment to TXX-04183 Page 7 of 13 Summary of Foreign Object/Loose Parts Identified During 2RF06 (cont)
SG Leg Row/Col Elev. First Found Shape Confirmed Resolution Removed ByW By 3 HL R37C55 TTTS NDE Wear N/A N/A Nothing found N/A 3 HL R38C55 TTS NDE Wear N/A N/A Nothing found N/A 3 HL R38C56 TTS 00NDE Wear N/A N/A Nothing found N/A 3 HL R6Cl14 ITS +Point Tube scale Visual Viewed 3" level and No found small tube scale piece attached to tube 3 HL R14C92 TIS +Point Sludge rock Visual Retrieved during Yes (approx. 0.4") FOSAR 3 HL R6C80 HII +Point N/A N/A Did not see with No video since upper bundle was not opened (no access),
leave in place, Eng.
Justification 3 HL Annulus TTS Video Various small items Visual Retrieved by Brooks Yes C34-58 inspection (14): 4/13/2002 mesh (1), weld slag (9),
sludge (1), wire (3) 3 CL Annulus TTS Video Various small items Visual Retrieved by Brooks Yes C67 inspection (12): 4/13/2002 sludge rock (1), weld slag (6), wire (5) 3 CL R43C93 B Video Bolt Visual Retrieved by Brooks Yes inspection 0.375"xO.625" 4/13/2002 3 CL R49C42 A Video Sheet metal Visual Retrieved by Brooks Yes inspection 4/13/2002 3 CL R20-21 A Video Various material (12): Visual Retrieved by Brooks Yes C55,56,57, inspection Sludge rock (1), slag 4113/2002 58 & 59 (6), machine curl (1),
._ _ .wire (1), mesh (3)
Attachment to TXX-04183 Page 8 of 13 Summary of Foreign Object/Loose Parts Identified During 2RF07 SG Leg Row/Col Elev. First Found Shape Confirmed Resolution Removed By By 1 HL T-slot C57 iTS Video Sludge Rock N/A Retrieved by Brooks Yes Inspection 0.188"x 0.375" 10/21/03 1 HL R7C3, TTS +Point Rough metal strip Video, Leave in place, No R8C2, wedged in place Bobbin, 2RF04 justification R8C3 NDE l _ History 1 HL R3C54 TTS Video Sheet Metal N/A Retrieved by Brooks Yes Inspection 0.031" x 0.25" x 0.50" 10/21/03 1 HL RI I C60 TTS Video Wire N/A Retrieved by Brooks Yes Inspection 0.016 " x 0.75" 10/21/03 1 HL R32C60 TTS Video Weld Slag N/A Retrieved by Brooks Yes Inspection 0.50" diameter 10/21/03
- HL R15C74 TIS Video Sludge Rock N/A Crumbled in SG No Inspection 0.375" diameter during Retrieval I HL R4C96 TTS Video Sheet Metal N/A Retrieved by Brooks Yes Inspection 0.031' x 0.25" x 0.50" 10/21/03 1 CL R3C13 TTS Video Weld Slag N/A Retrieved by Brooks Yes Inspection 0.250" x 0.500" 10/21/03 1 CL R35C26 TTS Video Sludge Rock N/A Retrieved by Brooks Yes Inspection 0.250" diameter 10/21/03 1 CL R14C59 TIS Video Sludge Rock N/A Retrieved by Brooks Yes Inspection ).125" x 0.500" x 0.500" 10/21/03 1 CL RI IC58 TTS Video Sludge Rock N/A Broke up when No Inspection .125" x 0.375" x 0.375" attempting to retrieve 1 CL R46C54, BP B +Point Curved Metal Video Retrieved by Brooks Yes R46C55 (C2) 0.5" x 0.375" x 0.25" Inspection 10/23/03 2 Tubelane - TS Video Weld Slag N/A Retrieved by Brooks Yes Nozzle Inspection 1.75" x 0.25" 10/18/03 2 HL T-slot - TIS Video Weld Slag N/A Retrieved by Brooks Yes R36C56 Inspection 0.375" and 0.125" 10/18/03 2 HL T-slot - TIS +Point Weld Slag Video Attempted Retrieval No R36C59 Inspection 10/18/03 - R36C59 and NDE was plugged at History at 2RF06 and 2RF06 dispositioned 2 CL T-slot TTS Video Wire N/A Retrieved by Brooks Yes Inspection 0.016" x 0.50" 10/19/03 2 CL R43C59 TITS Video Sludge Rock N/A Retrieved by Brooks Yes IInspection 0.188" diameter 110/19/03
Attachment to TXX-04183 Page 9 of 13 Summary of Foreign Object/Loose Parts Identified During 2RF07 (cont)
SG Leg Row/Col Elev. First Found Shape Confirmed Resolution Removed By By 4 HL R26C66 TIS Video Sludge Rock N/A Retrieved by Brooks Yes Inspection 0.600" diameter 10/19/03 4 HL R18C66 TTS +Point N/A 2RF03, Still could not find No I__I_2RF04 4 HL R23C79, TIS +Point Nail (-2") NDE Leave in place, No R23C80, History 2RF05 justification R22C80 4 CL R8C59 TTS Video Sludge Rock N/A Retrieved by Brooks Yes Inspection 0.315" diameter 10/19/03 4 CL R4C30 BP B Bobbin Scale Indication NDE Leave in place, No
._ (C2) History 2RF03 justification 4 CL R21C45, BP B Bobbin Metal Thread NDE Leave in place, No R22C45 (C2) History 2RF03 justification 4 CL R49C35/34 BP B + Point Bolt Piece N/A Retrieved by Brooks Yes
_(_2_ 0.25" x 0.50" 10/21/03 4 CL R43C92, BP B + Point Hollow Rod N/A Retrieved by Brooks Yes R43C93 (C2) 0.50" x 0.625" 10/21/03 4 CL R21 C69 BP B Video Metallic Remnant N/A Retrieved by Brooks Yes (C2) Inspection 0.25" x 1.00" x 0.125" 10/21/03 4 CL R21C47, BP B Video Crescent-shaped Piece N/A Wedged between No R21C48 (C2) Inspection 0.313" wide Tubes - Not Retrieved 4 CL R21C43, BP B + Point Sludge Rock N/A Retrieved by Brooks Yes R21C44, (C2) 0.75" x 1.00" 0.125" 10/21/03
__ R22C43 -
Attachment to TXX-04183 Page 10 of 13 Ouestion:
- 4. In the June 5, 2002 (2RF06) and June 30, 2004 (2RF07) reports, a 100% +Point*
inspection of all dented TSP intersections5 volt dented TSP intersections at the H3 TSPs in allfoursteam generatorswas reported. The NRC staff notes that dented/dinged locations can serve as initiationsitesfor axial and circumferential cracks. The staffnotes that both stress and temperatureaffect a tube's susceptibility to stress corrosion cracking. As a result, a smaller dent at a higher temperature may be as severe (from a stress corrosion cracking standpoint) as a larger dent at a lower temperature (materialpropertiesbeing equal).
4.a. Explain the basisforperforming +Point*inspections at the dentedH3 TSP intersections and not at other dented TSP intersections. Clarijyyour inspection scope and expansion criteriafor dented TSP intersections.
CPSES Response to 4.a:
This location (H3 - the lowest support plate in the hot leg, Hi being the flow distribution baffle plate) was conservatively selected as the likely first sign of the onset of SCC degradation at TSP intersections due to ding/dent related corrosion. Recognizing that the 405 stainless plate quatrefoil tube hole design largely precludes in-service denting in Model D5 SGs and any observed denting is likely related to the manufacture process. Also, the enhanced resistance of thermally treated Alloy 600 tubing, demonstrated to date by the absence of ding/dent-related cracking in D5, Model F and F-type replacement SGs further supports this limited inspection scope. Nonetheless, the following inspections were implemented.
2RF06: Initial inspection included 100% +Pt of> 5 volt dents at H3 TSP in SGs 2 and 3. If crack like indications were detected, expansion would have followed predetermined criteria. The minimum expansion would have included a 100% +Pt inspection of all dents at H3 and a 20% +Pt sample of the dents at H5 in all SGs. Additional expansions would follow based on the findings (i.e. ID or OD) and if the indications were not detected by bobbin.
2RF07: Initial inspection included 100% +Pt of > 5 volt dents at H3 TSP and 50% +Pt of > 5 volt dings in the hot leg (below HI 1) in SGs I and 4. If crack like indications were detected, expansion would have followed predetermined criteria. The minimum expansion would have included a 100% +Pt inspection of all dents at H3 and a 20% +Pt sample of the dents at H5 in all SGs.
Additional expansions would follow based on the findings (i.e. ID or OD) and if the indications were not detected by bobbin.
Attachment to TXX-04183 Page 11 of 13 Ouestion:
4.b. Discuss the extent to which the bobbin probe is qualified to inspect dented/dingedregions exceeding a specific voltage threshold (e.g., S volts).
CPSES Response to 4.b:
The bobbin probe is functionally equivalent to an Appendix H qualified probe to detect axial OD indications in lower voltage (* 5 volt) dent/dings per Westinghouse report SG-99-03-005, "Appendix H Certification of Bobbin Coil Detection Performance in Freespan Dings (South Texas Project)", March 1999.
Ouestion:
4.c. Confirm thatyour voltage normalizationschemefor determining the size of dents is consistent -withthe standardindustry approach (i.e.,
consistent with the approachdeveloped in support of Generic Letter 95-05).
CPSES Response to 4.c:
Even though the repair criterion of GL 95-05 is not applied for the Unit 2 steam generators, the bobbin voltage normalization is consistent with the approach developed in support of GL 95-05. This also includes use of calibration standards which have been normalized to the laboratory standard used in support of GL 95-05 database. Thus the dent/ding voltages reported from bobbin inspection are consistent with industry approach.
Attachment to TXX-04183 Page 12 of 13 question:
- 5. Describe what actions, if any, were taken to verify that the steam generatortubes wvere manufactured (i.e., regardingprocessing, heat treatment, etc.) as specified so as to exhibit optimal resistanceto degradation(refer to NRC Information Notice 2002-21 Supplement 1, dated April 1, 2003). If tubes with non-optimal tube processing have been identified, CPSES Response to 5:
SGs in CPSES Unit 2 have similar design characteristics (TT Alloy 600 tubes and stainless steel tube support plates with quatrefoil holes, though tube size is different) as Seabrook and could be susceptible to similar degradation (axial ODSCC at TSP intersections) as discussed in IN 2002-21 Supplement 1. Root cause investigation of the Seabrook indications led to the conclusion that the affected tubes had very high residual stress similar to tubes that were not thermally treated. Tubes with such condition could be identified from the full-length bobbin coil inspection signals. A procedure developed by Westinghouse uses bobbin signal profiles for tubes that are thermally treated after U-bending (rows 1 through 9 in Model D-5 SGs) and bobbin amplitude offset at U-bend tangent points for the outer row tubes. This procedure was applied prior to 2RF07 to the entire population of CPSES Unit 2 SG tubes in service using bobbin coil data from prior inspections. The tubes possibly having higher residual stress were identified and documented in a site-specific Westinghouse report LTR-SGDA-03-151, June 2003, "Comanche Peak Unit 2 Evaluation of Steam Generator Tubes for Elevated Residual Stress." These tubes (73 were identified as potentially having high residual stress) are shown in the following table. Inspection of these potentially affected tubes was made a permanent part of the Unit 2 Degradation Assessment prior to 2RF07 by the CPSES Corrective Action Program in response to IN 2002-21, Supplement 1. Subsequently, all tubes identified as potentially having high residual stress in SGs 1 and 4 were included in the 2RF07 bobbin inspection and the ITS +Point inspection programs with no indications identified.
Attachment to TXX-04183 Page 13 of 13 Listing of Identified Tubes with Elevated Stress No SGl1 SG2 SG3 SG4 Row Col Row Col Row Col Row Col 1 18 5 1 23 14 24 29 15 2 16 6 36 35 44 30 18 26 3 17 8 10 36 42 31 10 31 4 18 13 47 37 14 35 10 34 5 17 19 20 45 12 47 10 35 6 21 22 10 48 12 48 32 35 7 27 28 49 50 12 49 10 36 8 33 54 1 55 13 50 15 36 9 33 55 5 61 14 50 10 37 10 ._-::__ 31 81 12 52 10 53
. 2 88 14 57 28 55 12 .:1 89 11 58 13 77 13 .- _ 2 92 13 59 13 82 14 : 2 93 13 62 28 88 15 ;;1 95 44 63 15 103 16 -. . -: 11 65 . .
171 :. - :-.
24 66 . - _. _._-;, -;
18 . . 49 72 . . ____:
19 _. ; : 48 78 -.
20 ..: - 38 79 -. :
21 ^- ; _ 49 79 ____' _
22 . . .:_; 48 80 : .:. __
23 ; - ;:: 49 80 _ t _ ___'
24 _ .-. 48 81 ;- ___.
25 .- -7.
26 ______
27 : ;
_____ r Z1 14 48 48 83 83 84 r-28 _ _ 28 85 _ _ _; ::
29 .: 48 85 ;; _____. .
30 : _ 112 86 ._ ._ ._._ : .
31 _ _ : - 48 86 _ _ . .- _; . -
32 _. _ _ : .: 28 91 _ :_ _ .:
33 :-. ; . : :. - :;;; 38 93 .- _;:-. _______
34 1 - _ . ; . .. 25 102 .- -. _ _.