ML19347F519
| ML19347F519 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 04/30/1981 |
| From: | GENERAL PHYSICS CORP. |
| To: | |
| Shared Package | |
| ML19347F518 | List: |
| References | |
| PROC-810430, NUDOCS 8105190510 | |
| Download: ML19347F519 (15) | |
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Class 2 System Weld Program Enrico Fermi Atomic Power Plant Unit 2 30 April, 1981 hreparedby General Physics Corporation i
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O Class 2 System Wald Program Enrico Fermi Atomic Power Plant Unit 2 The purpose of this document is to define the extent of examination for the ASME Class 2 Inservice Inspection (ISI) Program for Enrico Fermi Atomic Power Plant, Unit 2. The program is based on the requirements of the Code of Fedcral Regulations, Title 10, Part 50 (10CFR50) and tne applicable editions and addenda of the ASME Boiler and Pressure Vessel Code,Section XI.
Currently 10CFR50 (i .e. 10CFR50. 55a (b) (2) (iv) (1 ) ) requires use of the 1974 Edition of Section "I with Addenda through Summer 1975 for determining the extent of examination for ISI of pressure retaining welds in Class 2 systems which perform an Emergency Core Cooling (ECC), Residual Heat Removal (RHR), or Containment Heat Removal (CHR) function. Other Fermi 2 Class 2 systems subject to ISI requirements, but not performing the above stated functions, fil also use the Summer 1975 Addenda as per-itted by 10CFR5).
The Fermi 2 Class 2 systems which perform ECC, RHR or CHR functions are as follows:
o Residual Heat Removal Division 1 and Division 2;
- CHR function in Containment Spray mode.
, e Core Spray - ECC function.
e High Pressure Coolant Injection - ECC function.
Other Class 2 systems which are included within the scope of the Inservice Inspection Program include the following: ,
e The portion of the RHR system which performs the head spray function, up to the Class 1 boundary valve.
i e Standby Liquid Control system, up to the Class 1 boundary valve.
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e Main Steam system between the second and third isolation valves.
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\J Paragraph IWC-1220 of the Summer 1975 Addenda identifies four exemption criteria for use in determining the extent of examination. The only exemption used by Detroit Edison for its Class 2 Weld Program is the exemption of systems with piping four (4) inches nominal pipe size or s.naller.
Detroit Edison applies this exemption to the Head Spray and Standby Liquid
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Control systems; their system piping is less than or equal to four (4) inches NPS.
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The Summer 1975 Addenda has two (2) _:tegories of pipe weld examination; C-F, for systems which circulate reactor coolant, and C-G, for systems which do not circulate reactor coolant. The basic examination requirements for these two categories are:
o C-F 100% of essentially one train must be examined over the 40 year plant life.
e C-G 50% of essentially one train must be examined over the 40 year plant life.
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Tables 1.1, 2.1, 3.1, 4.1 and 5.1 show the examination category (i .e. , C-F or C-G), the number of trains, the welds per train, the average number of welds per train, and the required number of weld examinations per train, for each major line in the Corc Spray, HPCI, Main Steam, and RHR systems, respectively.
Those tables are the basis for determin..ng the extent of examination. Detroit Edison will perform the number of examinations for each system as listed
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Minimum Number of Exams Number of Exams to be
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Required Per System Performed Per System System During 10 Year Interval During 10 Year Interval Branch Circum. Total Branch Circum. Total
( Core Spray 1 10 11 1 10 11 HPCI O 23 23 0 23 23 l Main Steam 1 3 4 1 4 5 I
( RHR 2 52 '54 2 52 54 The determination of the number of examinations required per system during l () a 10 year interval for this Class 2 Weld Program is in full conformance with 10CFR50 and Section XI (Summer 1975 Addenda) requirements with no deviations.
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The selection of the individual welds to be examined is based on the current inspection philosophy identified in the Summer 1979 and later Addenda of Section XI. The selection philosophy contained in the Summer 1975 Addenda is one based on a random selection of welds and results in examining a particular weld only once in the plant's 40 year life. No trending of data is possible under the Summer 1975 rules. The Summer 1979 Addenda embraces a selection philosophy that concentrates the examinations en those welds which history has shown to have a greater probability of failure; namely, high stress welds, welds at terminal ends, and dissimilar metal welds. In additiot., c/.e Summer 1979 Addenda requires examinations of the same welds each 10 year interval so that meaningful data trending can be accomplished. There is general agreement in the industry that the Summer 1979 philosophy is superior to the random selection approach identified in the Summer 1975 Addenda.
In developing the Fermi 2 Class 2 Weld Program the following categories
{} of welds were identified for each system:
e Terminal Ends - Defined as points where there is constraint in at least two degrees of freedom.
e High Stress Welds - Defined as follows:
Design Stress Value > 0.8 [1.2 Sh + SA ) as per the Summer 1979 Addenda.
e Moderate Stress Welde - Welds that have lower stresses than the High Stress Welds defined in Summer 1979 Addenda, but were considered in selecting welds for the Fermi 2 Class 2 Weld Program.
These welds are defined as follows:
- Design Stress Value > 0.7 [1.2 Sh +A S ) but is 1 0.8[1.2 Sh+S]*A Examination of these Moderate Stress Welds is an added conservatis, .
that exceeds the current Section XI philosophy.
e Dissimilar Metal Welds - No Dissimilar Metal Welds were identified in Class 2 systems requiring nondestructive examination.
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() The criteria for selecting the specific welds to be examined for each 10 year interval are as follows:
e A portion of the terminal ends were selected such that each type of '
terminal end contained in the system would be sampled. For example, the Core Spray system has four (4) pumps, each with a terminal end at the suction and discharge attachment welds. To examine all eight (8) terminal end welds would be redundant and would skew the examination sample to those particular welds. Therefore, to enable a more representative sample to be taken only one (1) pump suction and one (1) pump discharge terminal end weld were selected for examination.
e All High Stress Welds are examined, e All Moderate Stress Welds are examined, e All Dissimilar Metal Welds are examined. (None have been identified).
e Additional welds are randomly selected to bring the total number of welds to be examined up to the number identified in Tables 1.1, 2.1, 3.1, 4.1 and 5.1.
Based on the discussion above, Detroit Edison requests relief from two (2) of the Summer 1975 requirements for all the Class 2 system welds included ,
in their program. The first request for relief is to allow Detroit Edison to select those types of welds that history has shown to have a higher probability of failure in lieu of the random selection approach required by the Summer 1975 Addenda. The second request for relief is to allow repeated examination of the same welds in subsequent 10 year intervals in lieu of the requirements that different w,lds be inspected in each 10 year interval.
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Request for Relief #1
- 1. Identification of the component for which relief is requested:
All Class 2 pressure retaining welds subject to nondestructive examination.
4 2. Specific identification of the ASME Code requirement for which relief is requested:
Determining the extent of examination through random selection of welds as per paragraph IWC-2411 of the 1974 Edition, Summer 1975 Addenda,Section XI, ASME Code.
- 3. Information to support request for relief:
A selection process that concentrates the examinations in those welds which history has shown to have a greater probability of failure is more likely to detect incipient generic defects in pressure retaining welds and thus fulfill t!.e purpose of the ISI Program.
- 4. Specification of the inservice testing that will be performed in lieu of the ASME Code Section XI requirements:
i The same number of examinations per system will be' performed each interval as per Summer 1975 Addenda requirements with no deviations.
However, the welds to be examined will include a portion of terminal end welds, all High Stress welds as defined in Summer 1979 Addenda, all Moderate Stress Welds as defined in this submittal, and other we.'ds selected at random up to the total number required.
- 5. The schedule for weld examinations will be as per Summer 1975 Addenda requirements.
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O Request for Relief #2
- 1. Identification of the component for which relief it requested:
All Class 2 pressure retaining welds subject to nondestructive examination.
- 2. Specific identification of the ASME Code requirement for which relief is requested:
Examination of the different welds for each 10 year interval as per paragraph IWC-2411 of the 1974 Edition, Summer 1975 Addenda,Section XI, ASME Code.
- 3. Information to support request for relief:
Examination of the same welds each 10 year interval permits meaningful data trending to be accomplished. This is in compliance with the
() philosophy identified in more recent Addenda to the Code (i.e. Summer 1979 Addenda and later Addenda) as long as the examinations are concentrated on those welds that have a greater probability of failure.
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- 4. Specification of the inservice testing that will be performed in lieu of the ASME Code Section XI requirements:
The same number of examinations per system will be performed as per Summer 1975 Addenda requirements with no deviations. However, the same welds will be examined each interval. This Request for Relief is desired only if Request for Relief #1 (which concentrates the examinations to I
be performed on those welds that have a greater probability of fail:re) is granted.
- 5. The schedule for weld examinations will be as per Summer 1975 Addenda
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- l Table 1.1 4
ENRICO FERMI 2 i
i INSERVICE INSPECTION PROGRAM - ASME CTASS 2
- Sununary of Extent of Circumferential Weld Examination Core Spray System Line Description Iso Category Welds / Train Ave. Welds No. Exams 3 H C_ D Per Train Per Train Pump Disch. to Disch. IIcader 3144 C-G 7 7 7 j 7 7 3.5 3147
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Disch. Header to Class Break 3144 C-G 26 38 - -
32 16.0 3147
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i Torus to Suction lleader 3148 C-G 9 11 - -
10 5.0 3149
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Suction IIeader to Pumps 3148 C-G 8 13 9 14 11 5.5 3149
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CST to Suction lleader 3148 C-G 3 4 - -
3.5 1.75
[ Test Line 3145 C-G 14 9 - -
11.5 d.75
.' 3150 4
Minimic total required exams for CSS /40 years = 37.5 i.
e E2* amine 10 CSS Wolds each 10 year interval, for a total of 40 examinations over 40 years.
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- Table 2.1 *
$ ENRICO FERMI 2
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I INSERVICE INSPECTION PROGRAM - ASME CLASS 2 Summary of Extent of Circumferential Weld Examination
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High Pressure Coolant Injection System
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welds / train Ave. Wolds No. Exams
- Line Description Iso Category A 11 C D Per Train Per Train
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HPCI Turbine Exhaust 3162 C-P 42 - - -
42 42.0 '
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Pump Suction From I
Suppression Chamber 3163 C-G 21 - - -
21 10.5-and CST Pump Discharge To South Feedwater
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3167 C-G 28 - - -
28 14.0 fleader
- Test Line to CST 3169 C-G 8 - - -
8 4.0
} Steam Supply to IIPCI
Turbine Stop Valve 3172 C-F 21 - - -
21 21.0 Minimum total required exams for flPCI/40 years = 91.5
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ENRICO FERMI 2 l INSERVICE INSPECTION PROGRAM - ASME CLASS 2 I
j Summary of Extent of Circumferenti.1 Weld Examination
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Main Steam System Welds / Train Ave. Welds No. Exams Liha Description Iso Category A B C D Per Train Per Train
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Class 2 Main Steam 3258 C-r 8 9 8 8 8.25 8.25 i Lines from Outermost 3259 Containment Isolatiran Valves to 3rd Isolation Valves.
- Minimum total required exams for M.S./40 years = 8.25 1
- Examine a minimum of 3 M.S. Welds each 10 year interval for a total of a minimum I of 12 examinations over 40 years. Due to the selection criteria, Detroit Edison will examine 4 M.S. Welds each 10 year interval for a total of 16 examinations
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Table 4.1
- ENRICO FERMI 2 i
INSERVICE INSPECTION PROGRAM - ASME CIASS 2
- Summary of Extent of Circumferential Weld Examination Residual lleat Removal System k
Welds / Train Ave. Welds No. Exams Line Description Iso Category A C D L
11 Per Train Per Train Head Spray Line 3035 C-F 33 - -
33.0 33.0 4
i Torus Suction to 3153 C-G 5 6 6 5 5.5 2.75 i
Isolation Valve 3154 To Pump Suction Header 3152 C-F 7 7.0
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4.0 4.0 Pump Suetidns 3152 C-F 22 17 22 16 19.25 19.25
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3153 3154 Pump Disch. to 3157 C-F 16 15 14 15 15.0 15.0 -
fleader 3177 Discharge fleader 3157 C-F 14 12 - -
13.0 13.0 24 Inches 3177
[ 3158 Discharge Header 3158 C-f 15 15 - -
15.0 15.0 to lleat Exchanger
- lleat Exchanger 3146 C-F 32' 41 - -
36.5 36,5 Disch. to Class Change 3151 i To Fuel Pool Cool Unit 3669 C-F 11 - - -
11.0 11.0 S
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From Puel Pool Cool 36G8 C-F 7 - - -
7.0 7.0 Unit To Containment Spray 3159 C-G 17 29 - -
23.0 11.5 3164
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- l Table 4.1 (cont.)
1 j Welds / Train Ave. Welds No. Exams i Line Description Iso Category _ A B C, D Per Train Per Trrin i
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Test Line to Isolation 3146 C-F 2- 2 - -
2.0 2.0 f Valve V8-2155+V8-2156 3151 ,i Test Line to Torus 3160 C-G 8 8 - -
8.0 4.0 .;
3161 Torus Spray Line 3160 C-G 8 12 - -
10.0 5.0 3161 i
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HPCI Steam to-RHR 3171 C-F 5 5 - -
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Heat Exchanger <a 3173 i
1 Heleif Valve Disch. 4612 C-G 31 31 - -
31.0 15.5
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Minimum total required exams for RHR/40 years = 206.5
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t j e Examine 52 RHR welds each 10 year interval, for a total of 208
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1 Table 5.1 ENRICO FERMI 2 INSERVICE INSPECTION PROGRAM - ASME CLASS 2 Summary of Extent of r. ranch Wold Examination - CSS, HPCI, MSS, RHR Welds / Train Ave. Welds No. Exams ;
Line Description Iso Category A B C D Per Train Fer Train
- Core Spray System
- Pump Suct./Disch. 3144 C-G 1 1 - -
1 1.0
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- Full Flow Test 3147 C-G 1 1 - -
1 1.0
. 3144 Minraum total required Branch Connection Weld exams for CSS /40 years = 2.0 e Examine 1 CSS Branch Con'nection Weld each 10 year interval, for a total of 4 examinations over 40 years. '
High Pressure Coolant Injection System
- None identified.
Main Steam System
- Sweepolet to Drain 3258 C-F 1 1 1 1 1 1.0 Minimum total required Branch Connection weld exams for MSS /40 years = 1.G '
e Examine 1 MSS Branch Connection Weld each 10 year interval, for a total of 4 examinations over 40 years.
Residual Heat Removal System
- Full Flow Test 3146 C-G 1 1 - -
A 1.0 3151
- To Cont. Spray 3146 C-G 1 1 - -
1 1.0 3151 Rev. 2
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Table 5.1 (cor.t . ) i r
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1 Welds / Train Ave. Welds No. Exams Line Description Iso Category A B C, Per Train D, Per Train
- RHR (cont.)
- - To Head Spray 3151 C-F 1 - - -
1 1.0 j - To/From FPCU 3146 C-F 1 1 - -
1 1.0
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3 3152
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- From HEX Relief 3160 C-F 1 1 - -
1 1.0
} 3161
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- To Supp. Pool 3161 C-G 1 1 - -
1 1.0
- Spray 3160
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Minimum total required Branch Connection Weld exams for RHR/40 years = 6.0
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total of 8 examinations over 40 years.
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- Note: Per ASME Section XI, 1975 Addenda, IWC-2411(d), the number of examinations per train can not be less tha. one (1) . -
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