ML20150E618
| ML20150E618 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 11/10/1987 |
| From: | Sieber J DUQUESNE LIGHT CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| TAC-65713, TAC-66640, NUDOCS 8804010138 | |
| Download: ML20150E618 (18) | |
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One Oxford Ceritre November 10, 1987 301 Grant Street Pittsburon, f A 15279 Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, DC 20555
Reference:
Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Inservice Inspection Relief Requests Gentlemen:
Attached are thrt2 requests for relief from certain ASME Section XI inspection requirements for the following components:
a)
Pressurizer surge line radius b) 5t.eam cenerator nozzle radij c)
Non-regenerative heat exchanger CH-E-2 (Revision 1)
The revised relief request for the non-regenerative heat exchanger CH-E-2 supersede in total the previous relief request for CH-E-1 and CH-E-2 submitted on June 16, 1987.
The relief requests provide the Code requirements, Amendment 22 inspection requirements where applicable, a
basis for requesting relief and a
proposed alternate examination.
The code requirements listed in the relief requests have been determined to be impractical for Beaver Valley Unit No.
1 in accordance with 10 CFR 50.55a(g)(5)(iii).
Since these relief requests affect inspect'ons which must be performed during the sixth refueling outage, which is scheduled to begin on December 11,
- 1987, NRC disposition of "ha requests is requested as soon as practical.
Attached is a
check in the amount of $150.00 for payment of the application fee in accordance with 10 (.FR 170.
Very truly yours, J. D. Sieber Vice President, Nuclear Attachment cc:
Mr.
F.
I. Young, Sr. Resident Inspector (Unit 1)
Mr. J. Beall, Sr. Resident Inspector (Unit 2) h Mr.
W.
T. Russell, NRC Region I Administrator I
Mr. P. Tam, Project Manager Director, Safety Evaluation & Control (VEPCO)
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ReliGf RequeJt f:r the PrcO;uris r Surga Lina Nozzlo Radius 4
Component Pressurizer Surge Line Nozzle Radius Section (RC-TK-1, Radius 6).
Section II Requirement (74S75)
Item B2.2 (B-D) requires the volumetric examination of all of the nozgle inside radius sections during each inspection interval.
December 4, 1979 NRC Letter (Echwencer to Dunnj This letter allovs a visual examination to be substituted for the volumetric examination.
Basis for Ralief The 1979 NRC letter acknowledged that the volumetric examination of vessel nozzles vould not provide useful information because of both the thickness and geometr.ic configuration. Instead, it allowed an internal visual examination to be substituted for the volumetric examination.
In the case of the pressurizer surge line,a thermal sleeve and a diffuser screen are installed in the nozzle (see UFSAR Section 4.2.2.2 "Pressurizer")
UFSAR Figure 4.2-2 u ttached) depicts the screen and shows the relationship t) the pressurizer manvay.
These two fixtures preclude performing a visual examination of this area.
Therefore internal examination of the radius section of the surge line nozzle presents unusual difficulty and the, substitution of an external visual oxamination vould nst significantly affect the level of safety (the failure of line of this size is within the bounds of the safety analysis).
Alternate Examination 4
j The surge line nozzle vill be visually examined for leakage during the l
performance of the system leakage examinatione.
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ReliOf Request to P:stpone Steam Generat r Nozzlo Radius Examinations Components Steam Generator Radius Sections - Steam Generators B and C (RC-E-1B and -lC)
Section II Requirement (74S75)
Item B3.2 (B-D) requires the volumetric examination of all of the nozzle inside radius sections during each inspection interval.
December 4,1979 NRC Letter (Schwencer to Dunn)
This letter allovs a visual examination to be substituted for the volumetric examinations of the radius section.
Relief Requested Duquesne Light requests to defer the remaining examinations (RC-E-1B (cold leg) and RC-E-lC (both nozzles)) into the next inspection interval until the Steam Generators affected are opened for other examinations or repairs.
Basis for Relief During the Sixth Refueling Outage, only one steam generator (RC-E-1A) vill require eddy current examination.
Assuming that the results of that examination are satisfactory, there should be no need to enter the primary side of either of the other two steam generators.
The radius secticr. on RC-E-1A (both nozzles). and RC-E-1B (hot leg) vere examined in June of 1983 and no abnormalities were noted.
The estimated dose to open the primary side of one steam generator is 8100 mrem (see attached dose estimate).
The steam generator inside radii (from the evidence listed above) appear to be in satisfactory condition and the estimated radiation exposure involved in opening a steam generator solely to perform the subject examinations is high.
Therefore, deferring this examination until the generators are next accessible vould not significantly adversely affect the public health and safety.
Alternate Examination No alternate examination is proposed.
The examinations vill be performed at the next occasion'vhen the primary side of the steam generators is opened.
1 ATTAC19fENT 1 FAGE 1 OF 4
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3 TEAM GENERATOR, INSPECTIONS N0ZZLE INSII RADIUS SECTIONS' AND MANWAY CLAD PATCHES MANRDi ESTIMATE EQUIPMENT / CUBICLE DOSE RATE PROFILE (SEE ATTACHED FIGURES)
IDCATION RC-E-1A RC-E-1B RC-E-IC
- CII'ANNELHEAD DOSE RATES (2)
- HOT LEG TUBESHEET 43.0 R/hr 32.0 R/hr 40.3 R/hr
@ 18" FROM TUBESHEET 48.8 R/hr 29.0 R/hr 34.0 R/hr BOTTOM RADIUS OF CilANNELHEAD 34.0 R/hr 34.0 R/hr 27.0 R/hr
- COLD LEG TUBESHEET 43.6 R/hr 32.0 R/hr 40.3 R/hr
@l8" FROM TUBESiiEET 29.6 R/hr 29.0 R/hr 34.0 R/hr BOTTOM RADIUS OF CHANNELHEAD 28.4 R/hr 27.0 R/hr 27.0 R/hr eliOT LEG MANWAY(g) 1-1.2 R/hr 3.0 R/hr 3.5 R/hr
@l FOOT 600 mR/hr 1.0 R/hr 25,0 mR/hr
@2 FOOT 400 mR/hr 400 mR/hr 03' 120 mR/hr
- COLD LEG MANWAY 1-1.2 R/hr 3.0 R/hr 4.0 R/hr
@ 1 FOOT 600 mR/hr 1.7 R/hr 300 mR/hr
@ 2 FOOT 400 mR/hr 600 mR/hr @3' 150 mR/hr @3'
- WORK PLATFORM (g) 150-250 mR/hr 100-150 mR/hr 100-120 mR/hr
- EQUIP 'ENT/ PERSONNEL STAGING (g )
40-50 mR/hr 80-100 mR/hr 40-80 mR/hr AREA UNDERNEATli GENERATOR
- STAYTIME RATE ITTILIZED 700 mR/ min 600 mR/ min 700 mR/ min FOR CilANNFLHEAD JUMPERS (1) - ACTUAL OBSERVED DOSE RATES DURING THE FIFDI REFUELING OUTAGE - MAY,1986.
-(2) - CALCULATED DOSE RATES BASED ON TLD RESULTS DURING THE FIFTH REFUELING OUTAGE - MAY, 1986.
ATTACHMENP 1 PAGE 2 OF 4 STEAM GENERATOR INSPECTIONS NOZZLE INSIDE RADIUS SECTI'WS AND MANWAY CLAD PATCHES MANREM ESTIMATE STEAM GENERATOR INSPECTION ESTIMATE MANREM WORK TASKS 'IT) PREP STEAM GENERATORS ESTIMATE (area)
- REMOVE STEAM GENERATOR BOWL INSULATION 200
- REMOVE MANWAY STRONGBACKS 1500
- ERECT SCAFFOLD AND CONTAINMENT TENT 600
- REMOVZ DIAPHRAGMS AND INSTALL NOZZLE COVERS 1200
- INSTALL HEPA FILTERED VENTILATION SYSTEM S00 TOTAL TO PREP ONE GENERATOR (RC-E-1B) 4000 TOTAL TO PREP '1VO GENERATORS (RC-E-1B I.ND RC-E-lC)
(8000)
WORK TASKS TO PERFORM INSPECTIONS
- STEAM GENERATOR NOZZLE RADIUS SECTION INSPECTION ASSUMING A 1.5 MINUTE (90 SECONDS) JUMP TIME UTILIZING A STAYTIME RATE (3) OF 600 mR/ MIN FOR RC-E-1B ilOT LEG NOZZLE 900 COLD LEG NOZ7 %
900
- MANWAY CLAD PATCH EXAMINATION ASSUMING A 1.0 MINUTE (60 SECONDS) PARTIAL JUMP UTILIZING A STAYTIME RATE (3)
OF 600 mR/ MIN FOR RC-E-1B 600 (3) - ONCE A STAYTIME RATE IS E.'!ABLISHED, THAT VALUE IS USS'D FOR ALL CHANNELHEAD JIMPS OR PARTIAL JUMPS RECARDLESS OF WORK ACTIVITY. PLEASE NOTE ACTUAL ALLOWABLE CHANNELHEAD TIMES MUST BE PRE-AUTHORIZED FOR EACH INDIVIDUAL.
ATTACIMENT 1 PAGE 3 0F 4 STEAM GENERATOR INSPECTIONS N0ZZLE INSIDE RADIUS SECTIONS AND MANWAY CLAD FATCHES MANREM ESTIMATE 1
STEAM GENERA'IDR INSPECTION ESTIMATE i
MANREM WORK TASKS TO PERFORM INSPECTIONS - CONTINUED ESTIMATE (area)
- STEAM GENERATOR N0ZZLE RADIUS SECTION INSPECTION ASSUMING A 1.5 MINUTE (90 SECONDS) JUMP TIMP 'ITILIZING A STAYTIME RATE (3) 0F 700 mR/ MIN FOR RC-E-lC
!!OT LEG NOZZLE 1050 COLD LEG N0ZZLE 1050 i
WORK TASKS TO RESTORE STEAM CENERATORS
- REMOVE IIEPA I'!LTERED VENTILATION SYSTEM 300
- REMOVE N0ZZLE COVERS (REMOTELY)
- INSTALL D*APIIRAGMS 500
- REMOVE TENT AND DECON 600
- REMOVE SCAFFOLDING TO SUPPORT MANWAY INSTALLATION 300
- REINSTALL MANWAYS AND TORQUE BOLTS 1700
- REINSTALL INSULATION 700 TOTAL TO RESTORE ONE CENERATOR (RC-E-1B) 4100 TOTAL TO RESTORE 'INO GENERATORS (RC-E-1B AND RC-E-lC)
(8200)
(3) - ONCE A STAYTIME RATE IS ESTABLISHED, THAT VALUE IS USED FOR ALL CHANNELHEAD JUMPS OR PARTIAL JUMPS REGARDLESS OF WORK ACTIVITY. PLEASE NOTE ACTUAL ALLOWABLE CHANNELHEAD TIMES MUST BE PRE-AUTIIORIZED FOR EACII INDIVIDUAL.
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1 ATTACitGQfr 1 PAGE 4 OF 4 STEAM CENERATOR INSPECTIONS N0ZZLE INSIDE RADIUS SECTIONS AND MANWAY CLAD PATCHES MANREM ESTIMATE STEAM GENERATOR INSPECTION ESTIMATE MANREM WORK TASKS SUHMARY ESTIMATE (area)
- WORK TASKS TO PREP STEAM GENERATOR (S) 4000 RC-E-1B (8000)
RC-E-1B AND RC-E-IC
- WORK TASKS TO PERFORM INSPECTIONS 2400 RC-E-IB (4500)
RC-E-1B AND RC-E-IC
- WORK TASKS TO RESTORE STEAM GENERATOR (S) 4100 RC-E-1B (8200) 4 RC-E-1B AND RC-E-lC TOTA 1 ESTIMATED EXPOSURE FOR ONE GENERATOR 10500 4
TOTAL ESTIMATED EXPOSURE FOR 'IWO GENERATORS 20700 BASED ON llISTORICAL DATA FROM PREVIOUS OUTAGE EDDYCURRENT INSPECTIONS, APPROXIMATELY 40% OF THE TOTAL DOSE EXPENDITURE IS ATTRIBUTED TO PREPARATION AND THE SUBSEQUENT RESTORATION OF THE GENERATOR.
Tile REMAINING 60% EXPOSURE EXPENDITURE IS ATTRIBUTED TO EDDYCURRENT EQUIPMENT SET-UP, PROBI AND EQUIPMENT REPAIRS, EQUIPMENT TRANSFERS FROM HOT LEG TO COLD LEG MANWAYS, AND SUBSEQUENT PLUGGING ACTIVITIES.
PLEASE NOTE NO EXPOSURE ESTIMATE IS PROVIDED FOR RC-E-1 A SINCE THIS GENERATOR WILL BE OPENED DURING TIIE 6R OUTAGE FOR INSPECTION AND POSSIBLE TUBE EXPANSION.
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Bottom of Tuba Sheet' 43.0 R/hr 43.6 R/hr 19 18 18" 48.8 R/hr 29.6 R/hr Hot Les Cold Leg ManVay Lnvay l
1-1.2 R/hr 1-1.2 R/hr 34.0 R/hr 28.4 R/hr 400 mR/hr at 2' 150-250 mR/hr l
% Tent Sca# eld 40-50 mR/hr STE AM GENER ATOR S
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Bottom op Tuba Sheet 32 R/hr 32 R/hr 18 "
18
- 29 R/hr 29 R/hr -
Hot Les Cold Leg Mansay Mmway 3.0 R/hr -
3.0 R/hr 34 R/hr 27 R/hr 1.7 R/hr at 1' 1.0 R/hr at 400 mR/hr at 3 100-150 mR/hr l
CTent Sca# eld 80-100 mR/hr GTEAM GENERATOR A
C
i Bottom of 40.3 R/hr 40.3 R/hr Tuba Sheet i
or or 18 18
- 34.0 R/hr 34.0 R/hr-l Hot Leg Cold Lag Mas ay Lmray 3.5 R/hr f
4.0 R/hr mR/h a 250 mR/hr 150 mR/hr at 3' l
120 mR/hr at 2' 100-120 mR/hr f
I C Tent Sca#old 40-80 mR/hr
.I STEAM GENERATOR A
B 1
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Relicf Request fcr VOC cl V:lds on the Non-Regenerative Beat Exchanger (CB-E-2)
(Revision 1) 1 Componenti Non-Regenerative Heat Exchanger (CH-E-2)
Section II Requirement (74S75):
Table IVC-2600, Item C1.1, Category C-A, pressure-retaining velds in pressure vessels, requires that a minimum of five percent (5%) of each circumferential veld, uniformly distributed amo'ng three areas around the vessel circumference, be volumetrically examined each interval.
Relief Requested:
This requests the substitution of a visual leakage examination for the required 1.4* volumetric examination of two velds (to complete the first ISI interval).
Basis for Relief:
1 Radiation fields in the area of the Non-Regenerative Heat Exchanger (CH-E-2) are high [300-500 millirem per hour (mr/hr) in the immediate working area with hot spots of 7 REM per hour (R/hr)].
(These vere measured during the 1986 refueling outage and subsequent surveys have shown no decrease). The manrem estimate to prepare, inspect, and reinsulate the heat exchanger is projected to be 18 Rem.
This estimate is based on vorking space dose rates and i
estimated work durations as noted on the attached manrem estimate. This i
estimate represents an optimum vork schedule and any difficulties encountered would increase the dose. A draving is attached shoving the radiation survey results.
Previous examinations have not detected degradation of these velds. These velds vere examined in 1980 and 1982 vith no indications. This leaves 1.4" of l
each of the two head velds to be examined by the end of the interval to meet i
the ASME Code requirements.
The proposed (alternative) visual examination for leakage is a more effective examination for monitoring the integrity of the components than the Code required examination. The required examinations are of limited value because component geometry limits the volumetric examination of both velds to one side only. The endcap-to-vessel veld (Veld #1) cannot be examined from the endcap side and the flange-to-vessel veld (Veld #2) cannot be examined from the flange side.
These restrictions make i t, virtually impossible to obtain meaningful results from the volumetric examination of these velds.
Additionally, the nozzles and supports limit the examination from the vessel side. The affected velds are double-V butt velds in 0.625", SA-240 (Type 304) stainless steel in a vessel head of 27" outside diameter.
Drawing 8700-ISI-CHE2 is attached for information.
Page 1 of 3
e Because these velds are subject to routine monitoring during plant operation, veld degradation sufficient to cause a through-vall leak would be detected in a timely manner. There are several mechanisms to detect such leakage.
a.
The control room operators perform Operating Surveillance Test (OST) 1.6.2 "Reactor Coolant System Vater Inventory Balance" every three (3) days when the plant is operating at steady state conditions.
Leakage through the subject velds vould be detected by this OST.
b.
The inventory in the liquid vaste system is logged daily (log L3-11).
Since leakage from these velds vould be collected by the liquid vaste system and would be apparent in this inventory. The inventory is reviewed daily by the Stift Supervisor and veekly by the Site Radvaste Coordinator.
c.
Monthly, the Radiological Control Department personnel enter the c'ibicle to perform radiation surveys.
Slight leakage (less than that detectable by OST 1.6.2 or the liquid vaste inventory) vould be detected during this survey.
d.
OST 1.48.2 "High Energy Line and ECCS Inspection" is performed quarterly.
This visually examines accessible high energy lines outside of containment for degradation of velds on high energy systems (CH-E-2 is included).
The component is readily isolable should a leak occur. The heat exchanger is has double-valve isolation from the prim'ary system (LCV-CH-460A & B) and is automatically isolated on a pressurizer lov level signal.
It could be easily isolated by the control room operators should one of the velds be discovered to be leaking.
The radiological impact of a veld failure is not large.
NOTE:
Inservice inspection is intended to verify continued integrity of the pressure boundary.
It is not intended or expected to prevent or preclude the need for repair activity. The following is offered only as a comparison of manrem estimates.
This heat exchanger operates at 310 psi, 290' inlet, 115' outlet.
Even if a failure vere to occur on the inlet side, only approximately 8% of the water vould flash to steam (assuming an isentropic process and neglecting velocity).
Should either of these velds fail and begin to leak, the leakage vould be contained within the cubicle by the sill at the entryvay.
Leaking fluid vould be collected by the floor drain system.
The manrem estimate for the decontamination of the cubicle is 13.6 Rem. This estimate is based on vorking space dose rates and estimated work durations as noted on the attached manrem estimate.
NOTE: The dose estimate for examination is higher than that for decontamination primarily because of the surface preparation required to perform the ultrasonic examination (which vould be performed as part of the repair in the case of a veld failure).
I I
Page 2 of 3
The proposed alter.1stive examination can be performed for a small fraction of the exposure resulting from the Code required examination.
Since the examiner vould be subject to the radiation field for only a few minutes and could perform the examination without being as close to the 7 R/hr hot spot as for an ultrasonic examination, the resulting dose is expected to be less than 100 millires (mr).
Therefore, the proposed alternative examination reduces the exposure associated with veld examination and still provide an acceptable level of quality and safety.
Alternate Examination:
Visual examination for leakage during tha performance of the system leakage examinations. This is augmented by radvaste monitoring, radiation surveys, and OST 1.6.2 and OST 1.48.2.
Page 3 of 3
_._._m e
1 CG-C-2 IC27 CTIoe3 LETDOWW CWSICLE 722* PAB RAetER ESTIRATE
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Equi entsf/ Cx= I CI.E DOSE MATE PSerI LE I
j CN-E-2 NON-DEGENERATIVE LETDOWN MEAf EXCNANGEA WELD LOCATIO* 01 - 500 mR/br GENERAL AREA F LANGE SOLTING - 200-150 mR/hr GE'JER AL AOLA WELD LOCATIe5 02 - 300-500 mR/hs SENESAL ASEA 100-200 mR/hr GENERAL ASEA BOTTOM SELL OF MEAT EECMANGER - 7 R/hr (NOT FPOT)
INLET AND OUTLET FIFING
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LET DOWN CUBICLE (122* PASp SENEATE NEAT EECMANGERS 100 mR/hr GENERAL ASEA ASTICIPATED EXPOSust ESTINATES woma muNsEm or IsoIT: Duals TINE Is sAoIATIon MATE EurOsseE Tasa Amo JOs CLAssIrICAVIOss rIELo (Was)
(ma/hrp**
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INSTALL SCAFFOLDING 429 CARPENTEDS a
es) a (80 to 1003 1,000
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4901 SEnovE INSULATION
- 82) INSULATORS a
(2) a (200 to SCO) 1,200
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83003 WELD PREPPING 429 FIPEF1TTERS CN-E~2 WELD st a
123 a
(S003 2,000 WELD s2 m
(2) a 6200 to S003 2,000
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15003 WELD INSPECTION
- 82) INSPECTOR $
CM-E-2 WELD el a
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1500)
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(200 to S00s See
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(10) a (200 to 5003 10,000
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SENOVE SCAFFOLDING (2) CADPENTERS a
(4) a (40 to 1905 120
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(90) 10,000 ma TOTAL ESTIRATE
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- See Attached Dsagram Werksag Space Dome mates O
DECONTAMINATION AND REPAIR
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OF A POSTULATED WELD FAILURE ON CH-E-2 LETDOWN CUBICLE 722' PAB MANREM ESTIMATE EQUIPMENT /CUBICLEDOSENATEPROFILE CH-E-1 SEAL WATER HEAT EXCHANGER CH-E-2 NON-REGENERATIVE LETDOWN HEAT EXCHANGER WELD LOCATION #1 - 100 mR/hr GENERAL AREA WELD LOCATION fl - 500 mR/hr GENERAL AREA WELD ll) CATION #2 - 50 mR/hr GENERAL AREA WELD LOCATION #2 - 300-500 mR/hr CENERAL AREA FLANGE BOLTING 50 mR/hr CENERAL AREA FLANGE BOLTING - 100-150 mR/hr CENERAL AREA INLET AND OUTLET PIPING - 50 mR/hr GENERAL AREA INLET AND OITTLET PIPING - 100-200 mR/hr GENERAL AREA BOTTOM BELL OF HEAT EXCHANGER 3 R/hr (HOT SPOT)
BOTTOM BELL OF HEAT EXCHANGER - 7 R/hr (HOT SPOT)
LETDOWN CUBICLE (722' PAB) BENEATil HEAT EXCHANGERS 100 mR/hr GENERAL AREA (SPECIAL REQUIREMENTS)
THE AREAS FOR DECONTAMINATION WILL BE LIMITED TO THE IMMEDIATE CUBICLE AND AFFECTED COMPONENTS. THE I.
DECONTAMINATION AND Tile COLLECTION OF RESIDUAL WATER WITHIN Tile CUBICLE CAN BE ACCOMPLISHED IN A TIMELY MANNER BY USE OF STANDARD DECONTAMINATION MEDIODS. HOWEVER, DECOKTAMINATION OF THE HEAT EXCHANGER ENDBELL WILL REQUIRE THE REMOVAL OF THE IAGGING AND THE ERECTION OF SCAFFOLDING SINCE THE ENDBELL IS APPROXIMATELY 7'-8' UP FROM THE FLOOR.
IT IS HIG11LY UNLIKELY TilAT SHOULD ONE OF Tile WELDS FAIL 111AT THE FAILURE WOULD BE SO GREAT AS TO CAUSE A BURST OF THE LAGGING AND SPRAYING DOWN ADJACENT COMPONENTS. THEREFORE, DECONNING OF ADJACENT COMPONENTS SHOULD BE MINIMAL.
2.
DEPENDING ON THE SIZE AND CONFIGURATION OF Tile WELD FAILURE, CONSIDERABLE EFFORT WILL BE NECESSARY TO DECON THE REPAIR AREA TO ACCEPTABLE CONTAMINATION LEVELS. UlIS MAY REQUIRE THE REMOVAL OF INTERFERING OBSTRUCTIONS SUCH'AS SUPPORT BEAMS, CONDUIT, ETC.
3.
IN ORDER TO REDUCE TiiE RADIATION LEVELS ON Tile WORK PLATFORM, A LEAD SHIELD PIG WOULD HAVE TO BE FABRICATED AND CRIBBED UP UNDER Tile ENDBELL TO REDUCE TIIE DOSERATE ATTRIBUTED TO THE ENDBELL PROTRUSIONS.
(SEE ATTACHED FIGURE.)
4.
RESPIRATORY EQUIPMENT WILL MOST LIKELY BE REQUIRED TO PERFORM THE WELD REPAIR WELDING.
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