ML20033E010

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Final Technical Evaluation Rept on Response from Boston Edison to Generic Ltr 88-01 Pertaining to Pilgrim Nuclear Power Station
ML20033E010
Person / Time
Site: Pilgrim
Issue date: 07/31/1989
From: Bates R
VIKING SYSTEMS INTERNATIONAL
To:
NRC
Shared Package
ML20033E011 List:
References
CON-NRC-03-87-028, CON-NRC-3-87-28 GL-88-01, GL-88-1, NUDOCS 8908110321
Download: ML20033E010 (48)
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Text

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. ;i A liOS10N EDISON-TOGENERICLEySR88-011. <A-PERTAINING 10 THE-PILGRIM NUCLEld. PO'AR STATION a o 3, \\ \\. (5 h r -i ( puhished July, 1989 .. t 's .p prepared by~- a

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? Robert C. Bates i Armand Lakner i Viking Systems International-2070 Wm.'Pitt Way .t Pittsburgh, PA I Prepared for: i r. d y k "' U.S. Nuclear Regulatory Commission. i' ![j .t, Washington,-D. C. 20555 /^ under 1 [ h; Con, tract No. NRC-03-87-028, Task Order 005' \\ g4 'N 1, o i N ( \\ !) i' x t)

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~ /. q 7' I 4 4 ' ABSTRMT / m ll This report contains an evaluation of theilicensee (Boston Edison) 'a 1 submitt d for Pilgrim Nuclear Power Statica which was submitted in .~? response to the NRC Generic Letter AS-01 1n which Bostoij, Edison was ~ i requested to (1). Furnish their currenc' plans relating to pipitei replacement and other measures to mitigate'IGkC, inspect.Nn, re.f

pair,

/ and leakage detection. (2) Indicate whether they plan to follow the NRC Staff positions,.or propose alternative measures. Boston Edison's plans are evaluated in Section 2 of this report in terms of compliance to NRC Staff positions. Section 3 contains an evaluation of alternative positions concerning inspection of welds in portions of the RWCU, a-change to the Technical Specification on ISI, and sample expansion. t \\ e \\ \\ J A.~ l' t 4 h 1 e ( j l' )- a

( 2, l 1 SU! NARY The Licensee, Boston Edison, submitted a response to the NRC Generic I [ Let wr 88-01. Boston Edisor:'s response pertaining to the austenitic 4-st.ainless steel piping in the Pilgrim Nuclear Power Station (a BWR - nuclear power plant) was evaluated in terms oft (1) Their previous j and-planned actions to mitigate IGSCC to provide assurance of continued .[ long-term service. (2) Their Inservice Inspection (ISI) Program.. ( (3) Their Technical Specifications pertaining to ISI and their plans to ensure that leakage detection will be in conformance with the NRC Staff position. (4) Their plans to notify the NRC of significant flaws-identified (or changes in the condition of the welds previously known to be cracked) during inspection and evaluation of such flaws. r Boston Edison endorses 12 of the 13 NRC Staff positions which are outlined in Generic Letter 88-01, and proposed an alternative to one (the ce on sample expansion). 4 Comnonwealth Edison provided a list of welds at Pilgrim that are within the scope of Generic Letter 88-01, but they excluded welds in the RWCU t. that'are outboard of isolation valves from that list and from inspection plans. Extensive programs of piping replacement, piping removal, ) application of corrosion resistant cladding, and heat sink welding f have been conducted with the result that Pilgrim has 148 IGSCC Category A welds.- One weld has been weld overlayed. Although 93 welds have i ot received mitigating treatments, most of them have been inspected. n -and HWC has been implemented to assist in the mitigation of IGSCC. t f & detailed listing of. welds to be inspected during the next two refus11ng outages was submitted along with a summary of long range j inspection plans. The Inservice Inspection (ISI) program proposed' for Pilgrim conforms with the NRC Staff positions on schedule and on methods and personnel; however, Boston Edison presented nlternative positions to the NRC Staff position requesting a change to the TS on ISI and concerning sample expansion. i I s 11 9 L-1'

I E. CONTENTS t ABSTRACT i SUMHARY ............................. 11

1. INTRODUCTION 1
2. EVALUATION OF RESPONSE TO GENERIC LETTER 88-01 2

2.1 Documents Evaluated 2 L 2.2 Review of Boston Edison's Responses to Staff Positions and Implementation of Those Positions 3 [ f 2.3 Boston Edison's Classification of Welds, Previous Mitigating Actions, and Previous Inspections 5 2.3.1 Partial Replacement 5 l 2.3.2 Piping Removal 7 j 2.3.3 Last Pass Heat Sink Welding 7 f 2.3.4 Corrosion Resistant Cladding 7 8 l 2.3.5 Weld Overlay 2.3.6 Current IGSCC Classifications 8 i 2.3.7 Hydrogen Water Chemistry 11 2.3.8 Previous Inspection Program 12 2.3.9 Evaluation of Previous Mitigating 1 Actions and Inspections 14 2.4 Current Plans for Mitigating Actions 15 2.4.1 Summary of Plans 15 2.4.2 Evaluation of Conformance to Staff Positions and Recommendation 16 6 111 l

i 2.5 Plans for Future Inspections 17 2.5.1 Summary of Inspection Schedules ........... 17 2.5.2 Personnel and Methods . 18 2.5 B Sample Expansion 18 2.5.6.Y1ans for Uninspectable Velds 18 2.5.5 U n2uation and Recommendations 19 2.6 Changer du the Technical Specification Concertitt 3SI ...................... 20 2.7 Confira:utSon of Leak Detection i in the '!ethn:! cal Specification 20 2.7.1 Bor.:pn Edison's Position .............. 20 2.7.2 Ivinaction and Recommendation 23 2.8 Plans for Notification of the NRC of Flaws 24 2.8.1 Boston Edison's Position .............. 24 2.8.2 Evaluation and Recommendation 24

3. ALTERNATIVE POSITIONS AND EXCEPTIONS 24 3.1 Alternative Position on Welds in the RWCU.......... 24 3.1.1 Scope of Applicability of Generic Letter 88-01 24 3.1.2 Boston Edison's Position

.............. 25 3.1.3 Evaluation and Recommendation 27 3.2 Alternative Position on Sample Expansion 28 3.2.1 NRC Staff Position on Sample Expansion ........ 28 3.2.2 Boston Edison's Position .............. 28 3.2.3 Evaluation and Recommendation 29 iv i

[V;: 1.' -.c 3.3 Alternative PEsition Concerning 'ISI in the : Technical Specification' 29 3.3.1 Boston Edison's Position 29 L 3.3.2 Evaluation and Recommendation- -....... -... -... SOE

4. CONCLUSIONS AND RECOMMENDATIONS.

31, i

5. REFERENCES.

..................,.......... \\ 3 41 APPENDIX'A -......................,... ,...'A-1 1 9 l,, L o ~ Y

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1. IlirRODUCTION Intergranular stress corrosion cracking (IGSCC) near veldments in Boiling k'ater Reactor (Bk'R) piping has been occurring for almost 20 years. Substantial efforts in research and development have been sponsored by the Bk'R Owners Group for IGSCC Research, and the results of this program, along with other related work by vendors, consulting firms and confirmatory research sponsored by the NRC, have permitted the development of NRC Staff positions regarding the IGSCC problems.

The technical basis for NRC Staff positions is detailed in Reference 1 and further background is provided in Reference 2. The results of these research and development programs prompted the NRC to issue Generic Letter 88-01 (see Reference 3) requesting all licensees of Bk'R's and holders of construction permits to (1) Furnish their current plans relating to piping replacement, inspection, repair, and leakage detection. (2) Indicate whethet theyt (a) Plan to follow the staff positions, or (b) Propose alternative measures. Specifically, Generic Letter 88-01 stated that en acceptable licensee response would include the following items: (1) Current plans regarding pipe replacement and/or other measures taken or to be taken to mitigate IGSCC and provide assurance of continued long-tem piping integrity and reliability. (2) An inservice inspection (ISI) program to be implemented at the next refueling outnge for austenitic stainless steel piping. (3) A change to the Technical Specifications to include a statement + 1

e c in the section on ISI t. hat the inservice inspection program for piping will be in conformance with the staff positions on schedule, methods and personnel. (4) Confirmation of plans to ensure that the Technical Specification related to leakage detection will be in conformance with the Staff position on leak detection. (5) Plans to notify the NRC, in accordance with 10CFR$0.55a(o), of any flaws identified that do not meet IVB-3500 criteria of Section XI of the ASME Code for continued operation without evaluation, or a change found in the condition of the welds previously known to be cracked, and an evaluation of the flaws for continued used operation and/or repair plans. This report contains a technical evaluation of the response which Boston Edison (BECo) submitted in response to the NRC Generic Letter 88-01 i pertaining to the Pilgrim Nuclear Power Station (hereafter called Pilgrim or PNPS), t

2. EVALUATION OF RESPONSE 'IO GENERIC LETTER 88-01 This evaluation consisted of a review of the response to NRC Generic Letter 88-01 of January 25, 1988 by Boston Edison pertaining to Pilgrim to determine if their performance and plans are in conformance with the NRC Staff positions or if proposed alternatives are acceptable.

Proposed inspection schedules and amendments to the-Technical Specification were included in the review. l l 2.1 Documents Evaluated Review was conducted on the information pertaining to Pilgrim 2

4* a' provided by the Licensee in the following documents: (1) " Response to Generic Letter 88-01: NRC Position on IGSCC in BWR Austenitic Stainless Steel Piping," Docket No. 50-293, License DPR-35 Boston Edison, Pilgrim Nuclear Power Station. Rocky Hill road, Plymouth, Massachusetts 02360, August 4,1988. j 1 i (2) " Response to Request for Additional Information, Generic Letter j 88-01: NRC Positi$n on IGSCC in BWR Austenitic Stainless Steel Piping," Docket No. 50-293. License DPR-35, Boston Edison, Pilgrim Nuclear Power Station, Rocky Hill road, Plymouth, 1 i Massachusetts 02360 June 19, 1989. Hereafter, in this report, these documents will be referred to as the Boston Ediso'n Submittals No. I and No. 2, respectively, nnd collectively as the Boston Edison Submittals. 2.2 Review of Boston Edison's Responses to Staff Positions-and Implementation of Those Positions, i l Generic Letter 88-01 outlines 13 NRC Staff positions pertaining to (1) materials, (2) processes, (3) water chemistry, (4) weld overlay, (5) partial replacement, (6) stress improvement of cracked l veldments, (7) clamping devices, (8) crack evaluation and repair criteria, (9) inspection methods and personnel..(10) inspection schedules, (11) sample expansion, (12) leak detection, and (13) i reporting requirements. Generic Letter 88-01 states that the I licensee should indicate in their submittal whether they endorse these NRC Staff positions or propose alternative positions. A summary of the Boston Edison response to the thirteen NRC Staff positions is provided in Table 1. This table was prepared primarily with information provided in Boston Edison Submittal No. 2, although information from Boston Edison Submittal No.1 pertaining to partial 3 i

1-I l Table 1 Summary of Boston Edison's Responses to Staff Positions Boston Edison Boston Edison Has/Will Accepts NRC Applied Consider for Staff Position Staff Position in Past Future Use

1. Materials yes yes yes
2. Processes yes yes yes
3. Water Chemistry yes yes yes
4. Weld Overlay yes yes yes yes(a) y,,
5. Partial Replacement yes
6. Stress Improvement of Cracked Weldments,

yes no yes

7. Clamping Devices yes no yes-
8. Crack Evaluation and Repair Criteria yes yes yes
9. Inspection Method and Personnel yes yes yes yes(b) yes
10. Inspection Schedule yes
11. Sample Expansion no(c) y,,

y,,

12. Leak Detection yes(d) y,,(b) y,,
13. Reporting Requirements yes yes yes (a) The table in Boston Edison Submittal No. 2 (from which this table was prepared) listed "no" under this item. However, Boston Edison Submittal No. 1 listed several portions of the piping system that have been replaced.

See text for discussion. (b) Applied per Generic Letter 84-11. See text for discussion. (c) Alternative position presented. See text for discussion. (d) Regulatory Guide 1.45 is used for guidance, but it is not part of the technical specifications. See text for discussion. 4

'? replacement was incorporated. Note that Boston Edison endorses twelve of the NRC Staff positions, although they applied proviaions to one of these (that pertaining to leakage detection which is discussed in Section 2.7 of this report). They proposed an alternate position concerning the item on sample expansion. This alternate position is discussed in Section 3 of this report. Although Boston Edison endorses the NRC Staff position concerning inspection schedules and (3ncerning methods and personnel, they declined to change the TeCanical Specification for Pilgrim to reflect the NRC Staff position on ISI. Rather, they proposed an alternative position which is discussed in Section 3 of this report. I 2.3 Boston Edison's Classification of Welds. Previous Mitiratina Actions, and Previous Inspections l t Previous actions applied by Boston Edison at Pilgrim include partial replacement. (followed by solution heat treating), piping removal, Heat Sink Welding, Corrosion Resistant Cladding, weld overlay to repair one cracked weld, application of Hydrogen Water Chemistry, and inspections. These actions, which were performed during Refueling Outage # 6 (from December, 1983 to December, 1984), are j discussed in greater detail in the following sections. 2.3.1 Partial Replacement Boston Edison Submittal No. I lists the following systems that were replaced: Recirculation System 4 5 l i

Loops A and B with Type 316NG material. Reactor Pressure Vessel safe-ends at recirculation inlets and outlets for Loops A and B with Type 316NG material. Residual Heat Re: Oval System 20" supply piping from the recirculation piping tie-in to containment penetration X-12 (Weld Nos. 10-0-1 to 10-0-14) vith Type 316NG material. 18" return lines from the reactor containment penetrations X-51A and X51-B to the recirculation piping tie-ins (but.not including the penetrations) with Type 316NG material. ( B. loop piping outside the containment from Weld Nos. 10-IB-14 through 10-IB-16 with Type 316NG materin1. Core Spray System Loops A and B from the in-board manual valves 6A and 6B to the reactor containment penetration X-16A and X16B (but not including penetrations) with Type 316NG material. B Loop piping outside containment, containing Weld No 14-B-21 with Type 316NG material. _ Reactor Vater Cleanup System l RWCU piping from the branch connection on the Residual Heat Removal piping to the reactor containment penetration (X-14), but not including the penetrations 1 x i 6 l s

m + .s-l with Type 316NG material, t 2.3.2 Piping Removal Boston Edison Submittal No. I states that the following system was removed: Recirculation System l 22" equalizer valves and their. respective bypass lines. [ 2.3.3 Last Pass Heat Sink Welding P Boston Edison

  • Submittal No. 1 states that last pass heat sink welding (LHSW) was used for the following welds:

Residual Heat Removal System i t Applied to Weld Nos. 10R-IA-12 and'10R-IB-12. Core Spray System y Applied to Weld Nos. 14R-A-16 and 14R-B-16. Reactor Water Cleanup System j Applied to Weld No. 12R-0-23. I 1 2.3.4 Corrosion Resistant Cladding Boston Edison Submittal No. I states that corrosion resistant I cladding (CRC) used as follows: 5 7

L Residual Heat Removal System Applied to penetrution X518 flued head welds with Type 308L materin1. 2.3.5 Weld Overlay Boston Edison Submittul No. I states that the following weld was repaired with veld overlays-Rssidual Heat Removal S5 stem Applied to repair Weld No. RPV-N9A-1. 2.3.6 Current IGSCC. Classifications 1 The scope of Generic Letter 88-01 is defined as follows: "These Staff Positions apply to all BWR piping made of austenitic stainless steel that is four inches or larger in nominal diameter and contains reactor coolant at a temperature above 200'F during power operation regardless of Code classification..." Boston Edison excluded certain portions of the RWCU (i.e., ~ that portion outboard o" the isolation valves) from their IGSCC inspection program and has not assigned IGSCC classif1 cations to welds in that portion of the RWCU. They proposed an alternative to conducting IGSCC examinationswhichisdiscussedinSectioh3ofthis report. Thus, the remainder of Section 2 of this report is restricted to those piping systems within the scope of Generic Letter 88 01 exclusive of that portion of 8 i

the RWCU. Tables were supplied in the Boston Edison Submittals that provide listings of the IGSCC classifications of the welds at Pilgrim. The tables were similar in the two submittals except for the following: Boston Edison Submittal No. 1 included longitudinal seam welds which are outside of the scope of Generic Letter 88-01, and materials were described in terms of Boston Edison designations. Boston Edison Submittal No. 2 excluded longitudinal seam welds, and materials are described in terms of. industry designation. Boston Edison Submittal No. 2 lists Weld No. DC-10 FIOR (a pipe to valve weld in the Residual Heat Removal System) as an IGSCC Category G weld. According to Boston Edison Submittal No. 1, that weld is classified as IGSCC Category D. In the remainder of this report, the listing of welds as reported in Boston Edison Submittal No. 2 will be accepted as the correct list, and pertinent information from that 1 table is reproduced in Appenoix A of this report. A summary of the IGSCC classifications on a system-by-system basis is provided in Table 2. Note that the total number of welds at Pilgrim that are within the scope of Generic Letter 88-01 l is 242, including 148 IGSCC Category A welds, 80 IGSCC Category D welds,1 IGSCC Category E weld, and 13 IGSCC Category G welds. There are no IGSCC Category B, C, or F welds. 9 i 9 e

l ? L Table 2 Summary of IGSCC Classifications of Welds at Pilgrim ICSCC Pipe Dia. Total No. of Welds Caten. System inches of Indicated Dia. A RRR 20 14 18 26 RWCU 6 25 RPV 28 1 2 CS 10 18 Recire 28 34 22 8 12 20 Total IGSCC Category A Welds 148 D RHR 18 4 6 1 4 22 RWCU 6 ~11 4 20 CS 10 10 RPV 28 1 12 10 1 Total IGSCC Category D Welds 80 E RHR 18 1 Total IGSCC Category E Welds 1 G RHR 18 6 RWCU 4 2 CS 10 4 RPV 6 1 Total IGSCC Category G Welds 13 10

o .l 5 The IGSCC Category A welds are so classified because they j contain (with one exception) resistant ma'terials (per { guidelines in Generic Letter 88-01 and NUREG 0313, Revision

2) as may be seen by an examination of Appendix A.

The one exception is Weld No. 10R-1B-14 (a pipe to flued-head weld in the Residual Heat Removal System). This weld was mitigated i by application of CRC. Weld No. 10-1A-13A (also in-the RRR) was also corrosion resistant clad, but this weld is classified I as IGSCC Catgory G f.ar reason (s) not provided. Several RPV (Reactor Pressure Vessel) safe end to nozzle velds are classified as IGSCC Category D welds even though they are shown to contain only conforming materials (i.e., Type 316NG and low alloy steel). No explanatic,n was provided for the IGSCO Category D classifications rather than IGSCC Category A', but it is presumed that Boston Edison has a reason and the IGSCC Category D classifications will'be accepted 7 since they are more conservative. The remaining IGSCC Category D welds and the IGSCC Category G welds contain non-conforming materials, including Type 304 stainless steel, Type 316 stainless steel, and Inconel Alloy 600. As mentioned in Section 2.3.5, a weld overlay was applied l to repair one weld which contained a. flaw (Weld No. RPV-N9A-1). That weld is classified as IGSCC Category E. 2.3.7 Hydrogen Water Chemistry t 1 According to Boston Edison Submittal No. 1, Hydrogen Water 1 Chemistry (HWC) has been implemented and is expected to provide protection in the Residual Heat Removal System, the Reactor Water Cleanup system, the Recirculation system, the 11 i

j Core Spray system, and the overlay repaired jet pump instrument seal (Weld No. RPV-N9A-1). In addition a Crack Arrest Verification System was installed during Refueling detage # 7 to monitor crack growth and demonstrate the mitigating effects of HWC, 2.3.8 Previous Inspection Pronrams Boston Edison Submittal No. I did not describe previous inspections however, Boston Edison Submittal No. 2 contains a list of welds showing which welds were inspected (and-results of those inspections) during Refueling Outages No. 6 and No. 7 (Dec., 1983 to Dec., 1984 and April, 1986 to Dec., 1988, respectively). "'he detailed list is not reproduced in'this report, but a summary is provided in Table 3. This summary shows the number of welds of each of the various IGSCC Categories thnt were inspected during Refueling Outages No. 6 and No. 7. Commonwealth Edison indicated (as shown in Table 1) that they have applied methods and personnel per the NRC Staff positions. Note, however, that it applies only to Refueling i Outage No. 7 since Refueling Outage No. 6 occurred prior to the date that the NRC/EPRI/BWROG coordination plan was upgraded (September, 1985). During the two refueling outages a total of 17 IGSCC Category A welds were inspected (2 of these welds were inspected during each outage and 11 of which were inspected during the last outage). A total of 64 IGSCC Category D welds were inspected during Refueling Outages No. 6 and 7 (18 of the 64 welds l were inspected during each outago and 22 which were inspected during the last outage). Eighteen IGSCC Category D welds were not inspected during either of those refueling outages. i 12

?. Table 3 Summary of Inspection Schedules for Pilgrim No. of Welds Inspected / Scheduled IGSCC No. in Past __ Future Required by Caten. _Caten. R.O.#6 R.O.#7 R.O.#8 R.O.#9 . Generic Letter 88-01 A(8) 148 6 11 7 8 25% every 10 years (at least 12% $n 6 years) B 0 50% every 10 years (at least 25% in 6 years) C 0 All within the next 2 refueling cycles, then all every 10 years (at least 50% in 6 years) D(b) 80 60 22 41' 39 All every 2 refueling cycles E(c) 1 1 1 0 50% next refueling cycle, then all'every 2 refueling cycles F 0 All every refueling outage G(d) 13 0 0 9 0 All next refueling cycle Notest (a) Seven IGSCC Category A welds to be inspected each refueling cycle after R.O.#9. (b) 64 of the IGSCC Category D welds were inspected during R.O.# 6 and R.O.f7 (18 were inspected twice). 50% to be inspected each refueling cycle after R.O.#9. (c) The IGSCC Category E weld will be inspected every second refueling cycle after R.O.#9. (d) Nine IGSCC Category G welds will be inspected during R.O.#8 and then be reclassified as IGSCC Category D. The other four are inaccessible. See text for discussion. Dates for Refueling Outages aret R.O.f6 - 12/83 to 12/84 R.O.#8 - 01/91 to 03/91 R.O.#7 - 04/86 to 12/88 R.O.#9 - 05/93 to 08/93 13 .. J

l l l Concerning inspection results: no flaws were found except one in the previously mentioned Weld No. N9A-1. Commonwealth Edison Submittal No. 2 states the following about that weld: "An indication in the N9A-1 nozzle to safe end weld was ultrasonically located during RF0#6. A weld overlay repair was performed in accordance with BECo Procedure TP 84-258. The overlay was examined and found to be acceptable. The overlay was designed with the conservative assumptions that the indication is fully circumferential and extends through wall." "The N9A-1 weld overlay was re-examined during RF0#7. The results indicate that'the flaw has not propagated into the keld overlay. The ultrasonic test results also provided the following: (a) multiple indications in an 8" circumferential direction, (b) 0.55" maximum through wall dimension and (c) 0.65" original wall thickness." 2.3.9 Evaluation of Previous Mitigating Actions and Inspections Extensive mitigating actions have been applied at Pilgrim in the form of pipe replacement, pipe removal, heat sink welding, and application of corrosion resistant cladding. Of the 242 welds at Pilgrim which are covered by the scope of Generic Letter 88-01, 148 are IGSCC Category A welds. In addition, one veld has been repaired with weld overlay. These actions, applied to mitigate IGSCC, follow the i guidelines of Generic Letter 88-01 and NUREG 0313. Revision 2, so the IGSCC Category A and E welds have been correctly classified. Several safe end to nozzle welds were classified as IGSCC 14

N O Category D welds even though they are composed of conforming materials. On the other hand, 18 velds were classified as ICSOC Category D welds even though no inspections were listed for these welds during the inspection schedules included in the Boston Edison Submittals. It is presumed that, for each of these situations, Boston Edison had sufficient reasons for assigning the classifications. Certainly, the other welds classified as IGSCC Category D were correctly classified (they contain non-resistant material and have been inspected). It is recommended, therefore, that Boston Edison's IGSCC classifications of welds at Pilgrim should'be accepted. 2.4. Current Plans for Mitimatina Actions 2.4.1 Summary of Plans Boston Edison Submittal No. 1 contains the following summary of current plans for mitigating IGSCC at Pilgrim: "IGSCC mitigation efforts include implementation of Hydrogen Water Chemistry (HWC), limited Heat Sink Welding (HSW) and limited Corrosion Resistant Cladding (CRC). Other remedies commonly applied in BWR piping such as Induction Heating Stress Improvement (IHSI) have not { been used for IGSCC susceptible Class I piping at PNPS. There are no unrepaired cracked welds remaining in-service t at PNPS. However, a weld overlay repair was performed on a cracked jet pump instrument seal veld (No. RPV-N9A-1)." "HWC is expected to provide prctection against IGSCC in the RHR, RWCU, Recirculation Systems piping and l l 15

weldments Core Spray System piping, and the overlay j repaired jet pump instrument seal. During our current refueling outage.-(RF0#7), we installed a Crack Arrest. Verification System (CAVS) to monitor crack growth and demonstrats the mitigating effects of WC. License Amendment 118, dated 05/06/88,- according to Boston Edison i Submittal No. 1, revises the PNPS Technical Specification to accommodate permanent installation of the HWC system." l " Remaining piping susceptible to IGSCC is.being inspected I as referenced in our letter dated 05/06/87 'ICSCC~ Augmented Inspection Program Supplemental Information' which previded a summary of BECo's correspondence regarding our GL 84-11_ augmented inspections ~for ICSCC. Our response to item 2 of GL 88-01 provides an update to our IGSCC Augmented Inspection Program." 2.4.2 Evaluation of Conformance to Staff Positions _and Recommendation Extensive mitigating actt a. have already been applied'at i Pilgrim following the guidelines provided in Generic Letter 88-01 and NUREG 0313, Revision 2 The result is~that 148 of the 242 welds within the scope of Generic Letter 88-01 are IGSCC Category A welds and the only flawed weld'has been repaired using an acceptable weld overlay. Although 93 unmitigated, susceptible welds remain at Pilgrim and no additional mitigating treatments of these velds is currently planned, Hydrogen Water Chemistry has been implemented. The planned, continued use of HWC is consistent with the NRC Staff guidelines and should further reduce the possibility of IGSCC at Pilgrim. In addition, Boston Edison's~ISI program, as discussed in the following section, follows NRC Staff recommendations for schedules, methods, and personnel. 16 = r

l ? Thus, acceptance of Boston Edison's plan for mitigating IGSCC is recommended. i l e i 2.5 Plans for Future Inspections 1 2.5.1 Summary of Inspection Schedules i Boston Edison Submittal No. I states that the inspection I schedules for Pilgrim are being revised to reflect the requirements for inspection schedules as delineated in NUREG 0313 Revision 1 and Generic Letter 84-11. Boston Edison + Submittal No. 1 also contains a a summary of the inspection plans for the Refueling Outages No. 8 and No. 9 which consists of the number 'of welds of each IGSCC category that are scheduled for inspection during those outages. Boston Edison Submittal No. 2, which was submitted in response to a request for additional information, contains detailed (weld-by-weld) { inspection schedules for Refueling Outages No. 8 and No. 9 and identifies the specific welds scheduled for inspection during tihose outages. Those detailed schedules are not reproduced in this report, but the numbers of welds of each IGSCC category scheduled for inspection are presented in Table 3 which also contains the previously discussed inspections of the last two refueling outages and the NRC Staff guidelines for inspection schedules for t.he various IGSCC categories. This table reflects the plans as presented in Boston Edison Submittal No. 2. eese plans differ slightly from the su amary of plans presented in Boston Edison Submittal i No. 1 (the differences occur only for Refueling Outage No. 9). Boston Edison cautioned that adjustments may be made in the future, although they will adhere to the NRC Staff guidelines. 17

E l l. Note, from Table 3 that planned inspection schedules for all three of the ICSCC categories of welds contained at Pilgrim (except for inaccessible welds which are discussed in Section 2.5.4) comply with the NRC Staff guidelines. Recall, however, that this section does not address the portion of the RWCU that is outboard of the isolation valves. Recall, also, that those welds, are discussed in Section 3 of this report. ( 2.5.2 Personnel and Methods Inspection procedures, equipment, and examination personnel used to perform inspection on piping welds within the scope of Generic Letter 88-01 will be in accordance with and comply with the NRC Staff position and will be qualified under the EPRI/NRC/BWROG Coordination Plan. 2.5.3 _ Sample Expansion Boston Edison proposed an alternative position to'the NRC Staff position concerning a Sample Expansion. This alternative position is discussed in Section 3 of this report. 2.5.4 Plans for Uninspectable Welds Boston Edison Submittal No. 1 states the followings "Four ICSCC Category G welds are uninspectable because of their inaccessibility to UT inspection methods. Two of these welds (Weld Nos. 12-I-20 and 12-I-22) will be monitored for leakage by daily plant operator tours. The other two welds (Weld Nos. 10-IA-13A and 10-IA-13B, (ono of which is a Corrosion Resistant Clad weld), will be monitored by the Drywell Leakage Detection System." l 18 i i 1 l l

4 Boston Edison Submittal No. 2 elaborates as follows: "Four Category G piping welds have not been inspected due to their inaccessibility to UT or RT inspection methods. Two welds, 12-I-20 and 12-I-22 will be monitored for leakage by daily-plant operator tours. The remaining two welds, 10-IA-13A and 10-IA-13B, are located within drywell penetrations. Weld number 10-IB-13 is a Corrosion Resist. ant Clad weld but is inaccessible. Any leakage from these welds would be monitored by the Drywell Leakage Detection System." "In addition to the above information from our Generic Letter 88-01 submittal we. provide the'following plans for mitigation / inspection. Welds that can be examined for 90% of their length from at least on side are considered accessible for UT examination. Welds that do not meet this criteria shall b replaced, sleeved, have local leak detection applied, be radiographically -l examined, or be visually inspected for leaks." 2.5.5 Evaluation and Recommendations i Boston Edison's planned, augmented ISI plans (excluding the RWCU piping that is outboard of the ! Jolation valves) complies with the requirements of Generic Letter 88-01 and NUREG 0313, Revision 2 for schedule and for methods and personnel. Thus, acceptance of these plans is recommended. -(See Section 3 for recommendations concerningt (1) sample expansion and (2) RWCU piping that is outboard of the isolation valves). Boston Edison's plans for inaccessible welds comply with the guidelines provided in note (3) of Table 1 of Generic Letter 88-01. Thus, acceptance of their plans is recommended. 19 1 I l

I. t 1 2.6 Channes in the Technical Specification Concerning ISI Boston Edison proposed an alternative position to the NRC Staff position concerning a change to the Technical Specification. This alternative position is discussed in Section 3 of this report, 2.7 Confirmation of Leak Detection in the Technical Specification. 2.7.1 Boston Edison's Position Boston Edison's position regarding leakage detection is provided in Boston Edison Submittal No. 2. Table 4 of this report, constructed from a similar table in that submittal, shows their positions on each of the leakage detection requirements as delineated in Generic Letter 88-01. Note that the Pilgrim Technical Specification currently contains requirements that are in compliance with the NRC Staf f position concerning total unidentified leakage (maximum of f 5 gpm),' definition of unidentified leakage, and provisions for shutdown due to inoperable measurement instruments. Note, also, that requirements will be added pertaining to two items (i.e., that pertaining to an increase of unidentified leakage (allowing a maximum of 2 gpm) and requirements concerning frequency of leakage monitoring), and Boston Edison presented an alternative position concerning conformance to Regulatory Guide 1.45. These items are discussed below. l Concerning the requirement concerning a maximum increase in unidentified leakage of 2 gpm, Boston Edison Submittal No. 2 referred to the following statement in Boston Edison 20 e--

Table 5 Licensee Positions on Leakage Detection Already TS will be Alternate Contained Changed Position Position _ in TS to include Proposed

1. Conforms with Position C of yes(*)'

Regulatory Guide 1.45

2. Plant shutdown should be initiated when:

(a) within any period of 24 hours yes(a) or less, an increase is indicated in the rate of unidentified leakage in excess of 2 gpm, or (b) the total ut. identified leakage yes attains a rate of 5 gpm.

3. Leakage monitored at four hour yes(a) intervals or less.
4. Unidentified lealage includes all t

yes except: (a) leakage into closed systems 1 or (b) leakage into the containment atmosphere from sources that are located, do not interfere with monitoring systems, or not from throughwall crack.

5. Provisions for shutdown within 24 yes hours due to inoperable measurement instruments in plants with Category D, E, F, or G welds.

(a) See text for comments. 21 1

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( $Q Submittal No. 1: o s, e i "A Boston Edison letter, dated 02/04/85, from Mr. W. 1 D..Harrington to Mr.-D. B. Vassallo proposed Technical Specification changes in accordance with guidance provided 4 4, by Generic Letter 84-11 t, 3 This request remained open g, b; q pending issuance of the NUREG 0311 rev)fdonynd is yt assigned TAC number 56835. A comparjson between GL 84-11 " and GL 88-01. requirements' identified enly minor editorial differences. Therefore, no further,Tii<hnical Specification changes beyond those already requested : are considered necessary." i kly { s

r. -

Concerning frequency of leakage monitoring, C,4 eric Letter 88-01 states: qg t s i V "For sump level monitoring systems with f ed mossurement-4. intervalmethods,thelevelshouldbemdp,wredat d g approximately 4-hour intervals or less.,"h' j '} 7 ,i, 3 ) > ')

  • s

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l As indicated $n Table 4 of this report, the comparablegabic h, If f in Boston Edison Submittal No. 2 statii.s that they will enany

't their TS to comply with the 4-hour. rDquirement..However, they attached the following note. s d -3, .p "In our February 4,1985, BECo requested a or/. .:e per 8 hour monitoring interval as PNPS does not have a fixed s pump interval on the drywell sump pumps. Aldo,the Pilgrim recirculation pipe nplacement reduces the 3[t,, probability of.the type of leaks from unidentified sources a' for which detection systems are installed." , ;\\ /, ^ Concerning conformance with Regulatory Guide 1.45, Boston \\ Edison Submittal No. 2 states: T h 22 .\\ ( s ./ i' c i' n_,

y.f i.' S '( ./ ' b, ~,. " Regulatory Guide 1.45 is used as guidanca when >\\ q modifications are made to the Pilgriq leal detection j; 'l .s. systems however, it is not a part of t*o. techaical 4 specifications."

" j v,

s , ;y i 2.7.2 Evaluation and Recommendatio3 3, 1 L\\ Ir.asmuch as Regulatory Guide 1.45 is used as guidance for ~t o modifications of the Pilgrim Technical Specification. i 3, acceptance of this aspect of Foston Edison's position is i \\ i recommended. Acceptance of the following, additional aspects i, of Boston Edison's position en leakage' detection is also- .I recopiended since they adhero to the NRC Staff guidelines and'are either already contained in or will be added to the ^ s \\ f \\ Teshnical Specifications (1) A 11mic of 2 gpm in the increase t b Y _{ in unidentified 2takage. (2) A limit of 5 g'pm for the total ' knidentified leakage. (3) The definition of unidentified' 'b -( leakage, and (4) provisions for shutdown in the event of, p .imporable measurement instruments. d h =/ A 'b ) Concerning frequency of leakage monitoring: Boston Edison's p J position is somewhat ambiguous. On the one hand, they stated [ v' that they will charge the Pilgrim Technical Specification ,s j to include the requirement to monitor leakage. On the other s 3x'g hand, they stated that they had roquested an 8-hour interval y rather than a 4-hour interval as required by Generic Letter .j 88-01 It is recommended that Eoston Edison should change s' the Technical Specification to require leakage determinations S b>{atapproximately4-hourintervalsorless. } ) N / 3 al n

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tf 7, v. a l.' 2.8 Plans for-Notification of the NR9 of Flaws 1 2.8.1BostonEdison'sPosition( 'h h 4 h ,.A BostonEdisonSubsQtal: No,',71" states that reportability.to the NRC of discovered flaws in piping is addressed by present-Pilgrim corrective action procerses that will be rev5 4ed' . prior to th'e.next scheduled inspection to' accommodate the notification requirements _of Generic Letter 88-01. p .I '2.8.2 Evaluation and Recomtnendation; / t ti g SinceBostonEdisonplanstocomplywiththeNRCSta{f 3 position, it is recommended that the plans for reporting p of flaws shoul'd be tentatively accspted,;pending receipt <E of the actual change' in the 'prxedi te fo'r' Pilgrim. + -r ? ) S- ) ,1. 4') t \\

3. ALTERNATIVFiPOSITIONS-AND EXCEPTIONS 1 g,w'

( !p ,j [ 3.1 Alternative Position Concernina Portionskof the RWCU j 'L l 3.1.1 Scope of Applicability of Generic' Letter 88-01 'lf Generic Letter 88-01 describes the Jcope of applicability. as follows: J .c "This Generic Letter applies to all BWR pipin8 made of / l' ' austenitic stainless steel that is four. inches or larger in nominal diameter and contains reactor coolant at a j 7 ! temperature above 200'F during power operation regar.ileas i 'i ,of Code Classification. It also-applies to reacto'r #essel . attachments and appurtenances such as Jet pump instrumentation penetration assemblies and head spray e 24 j [ / g i, f. A l [: -_ 1 s c g ~. (.,3,g .p

I * .'e.. U:' ' and.- vent components." ff 3.1.2 Boston Edison's Position - I / A Boston Edison presented an exception to that scope pertaining { 'to RWCU piping that is outboard of the~1 solation-valves. They:also proposed an alternative to the inspection q. , requirements. Their position, from Boston Edison Submittal' i No. 2, is presented.below: / "No' welds'beyond Code classification (1.e., beyond the (i; isolation valves) are listed... " l i " Boston Edison considers this Generic. Letter \\ j -recommendation to be an expansion-of-the scope of-IGSCC: augmented weld inspections beyond ASME Code classification e piping (for example,-Reactor Water Cleanup piping outboard of the isolation valves)." 1 "The RWCU is a non-safety related' system that:is designed to be automatically isolated if a pipe break downstream ) of the isolation valves were to occur. Two motor-operated . isolation valves, one on'either side of the primary containment, are automatically closed by signals'from instrumentation installed to detect breaks in the RWCU system, among other isolation signals. Pipe breaks or leaks in the RWCU room would be detected by a high i temperature indication, a high flow indication or a combination of both." l "Therefore, by design, a severe break in the RWCU piping r would trigger the automatic isolation from aither.high temperature in'the RWCU room or from a high flow indication in the RWCU piping, alerting operators to ' f, 25 i

e i 9 the break. In'additidn,sinceIGSCCisa: slow deterioration process, any leak in piping susceptible. + to it would. develop slowly,' allowing. time for operators l to detect the leak, isolate the system, and repair the leak." l Additional reasons that were offered by Boston Edison are k (1) Weld inspections'in this portion of the RWCU would' A l-q 'be contrary to ALARA practice due to the high personnel exposure with little gain in the reliability i of the-system. They estimate that exposure would' .be aboutL57.2 Rem for the first inspection and 28.6 Rem ~per'each.aubsequent outage. i (2) Fourteen welds in the portion of the RWCU thac'is inboard (upstream) of the isolation valves (code-portion)'are subjected to an.IGSCC environment similar.to the 44 welds in the non-code. portion of, i 1' the RWCU, so the 14 code-area welds constitute a representative sample of welds in the entire RWCU. i l 1 (3) The 14 welds in the code-area are IGSCC Category D, so 507. of those welds will be inspected durin8 l each refueling outage. .? (4) Boston Edison intends to use Hydrogen Water Chemistry, ( and as discussed previously, HWC will reduce IGSCC : I -in welds in the RWCU as well as other piping systems. The alternate proposal offered by Boston Edison, as stated' ~t in Boston Edison Submittal No. 2, is: "As an alternative to conducting IGSCC exams of the RWCU f \\ 26 .[ i

[ piping welds that are downstream of the isolation. valves, we propose the following.- If, during our weld inspections of the Code related RWCU piping, we find any indication of IGSCC, we will apply the sampic expansion criteria of NUREG 0313,' Revision 2,1as modified in our response J to GL 88-01', to the code related piping and; include ~the non-code related welds in the sample scope.-This proposal-would keep radiation' exposure AIJ.RA while providing added assurance of identifying IGSCC~related cracking in the non-code RWCU piping." 3.1.3 Evaluation and Recommendation The NRC Staff, in the development of their. position as delineated in Generic Letter 88-01, included all austenitic piping that is greater than four inches-in. diameter and contains reactor coolant at a temperature above.200*F. Generic Letter 88-01 specifically includes all'such piping. regardless of Code classification. The NRC Staff, in: -developing this position, recognized that high radiation-exposure to inspectors would= result; however,;the benefits ~ of added reliability.(including reduced leakage as well as reduced probability pipe rupture) outweighs those considerations. Thus, rejection of Boston Edison's' position is recommended. It is also recommended that Boston Edison should perform inspections of these welds in keeping with the directions of Generic Letter 88-01 for IGSCC Category G welds. le 27 \\

o.. 3.2-Alternative Position on Sample Expansion-3.2.1 NRC Staff Position on Sampla Expansion. t Generic Letter 8%01, regarding sample expansion, states, in part: "If one or more' cracked welds in IGSCC Categories A, B, or C, are found by a sample inspection during the

10. year interval, an additional sample _of!the welds in that category shall-be inspected.:approximately equal in number to the original sample...."'

i 3.2.2-Boston Edison's Position Boston Edison proposed an alternative to exact conformance l to the NRC Staff position concerning sample expansion which would allow them to reduce the size of the expanded-samples j when technically. justified. Boston Edison cited the following. i excerpt from Generic Letter 88-01 in-support of their i position. l "This additional sample should be similar in distribution (according to pipe size, system, and-location) to the 1 original sample, unless it is determined that t$here is a technical reason to select a different distribution."' l .) The Boston Edison position is detailed in the following statement which is quoted from Boston Edison Submittal No.- 1. j ) "In the event that cracks are'found in IGSCC category A, B, or C piping welds during the 10 year-interval, 28

an additional sample of welds'approximately equal in number to the original sample will be inspected. The 1 size and. distribution of an expanded sample will be subject to.a technical justification / evaluation by:the ~ Boston Edison Nuclear Engineering Department using the guidelines provided by GL 88-01;(NUREG 0313 Revision

2) and.the appropriate ASME Section XI code sections."

l = "The staff position allows for technical evaluation-for q determination of sample expansion distribution (according l to pipe size, system and;1ocation).when cracks are found." 3.2.2 Evaluation and Recomraendation 1 4 The NRC Staff position on sample expansion allows a technical 1 evnluation of the sample distribution, but not sample size, requiring instead a sample size a.pproximately' equal to the q original sample. This position. allows sufficient' technical' ^ evaluation concerning sample expansion. The Boston Edison 1 j E proposal is not in. keeping with the NRC Staff. position and opens the possibility'of abuse of the intent of the NRC, Staff position. [ Thus, rejection of' Boston Edison's position is recommended. It is further recommended that requirements for sample expansion in agreement with the NRC' Staff. position. should be included in the ISI program and the modif:'. cation ( of the Technical Specification on ISI which is discussed in the following section. 3.3 Alternative Position Concerninn ISI'in the Technical Specification 3.3.2 Boston Edison's Position Boston Edison's position is not to change the Technical 29

{ .s 4- ~ t Specification to specifically delineate conformance concerning inservice inspection'(ISI). The reasons given by Boston l Edison are. quoted below, i "Section 3/4.6.G;" Structural' Integrity",.of the PNPS (Pilgrim) Technical specifications,' contains reference l to appropriate ASME codes and'to the ISI Program for l . Pilgrim Station. IGSCC inspections,-conducted to comply-with Generic Letter 84-11,:are: considered ISI Program related augmented, inservice' inspections (

Reference:

10CFR50.55a(g)(6)(11)). Because the GL 84-11 requirements 1 'have been superseded by GL_88-01, we now consider GL 88-01 inspections to. be augmented inspections. As' such, 'any technical specification change. to specifically reference,GL 88-01 would be redun(ent to that which is presently in the PNPS Technical Specifications and - required by the Code of Federal Regulations. t "Also, using the 3 criteria provided in the NRC Interim t Policy Statement on scope and purpose ~of Technical-Specifications, (52 FR 3788) dated 02/06/87,.we-have determined'that the addition of a reference to Generic f L Letter 88-01 does not meet any of-the criteria." 3.3.2 Evaluation and Recommendation l The NRC Staff, in the development of their position and the requirements concerning ISI contained.in Generic-Letter 88-L 01, specifically considered and rejected an alternative approach similar to that proposed by Boston Edison..i.e., to add the required statement to the ISI program' rather than to the TS. Thus,. rejection of Boston Edison's position is o p recommended. It is further recommended that Boston Edison I should add the requested' statement on ISI (that the ISI 30 i a w. u .r -u

'4 ,8g e program will conform to the NRC Staff position on inspection schedule,. methods and~ personnel, and sample expansion) to the Technical Specification at Pilgrim.

4. CONCLUSIONS AND RECOMMENDATIONS

-Concerning the thirteen NRC Staff positions as delineated in Generic Letter 88-01: Boston Edison endorses twelve of the' thirteen NRC Staff positions (i.e., those pertaining to materials, processes, water-chemistry, weld overlay, partial! replacement, stress improvement of . cracked weldments, clamping devices,. crack evaluation'and repair. criteria, inspection methods and personnel, inspection. schedule, leakage detection, and reporting ~ requirements). They presented an alternative. proposal to one of'the positions (i.e., that pertaining to sample expansion). Boston Edison proposed to exclude welds in the portion of the'RWCU f outboard of the isolation valves from the scope of applicability of Generic Letter 88-01 because they are non-code related. 'They proposed an alternative position that 14 welds (all IGSCC Category D)' in-the -

a RWCU that are inboard of the isolation valves would be inspected per guidelines provided in Generic Letter 88-01, and those inspections j

would sorve as a sampling of the entire RWCU. In the event that cracks I were found in that sampling, sample expansion would extend to the non-code portion. In contrast, the NRC Staff position specifically excludes code classification as a criterion for applicability of the requirements of Generic Letter 88-01. j Pilgrim containo 242 9 elds in the code-related, austenitic piping systems which are classified as follows: 148 IGSCC Category A welds,- 1 IASCC Catecory E weld., 80 IGSCC Category D welds, and 13 IGSCC Category G welds (four of which are inaccessible for UT' inspection). T'- i:arge number of IGSGC Category A welds is the result of extensive ~ ' 31

,I <5 ~ piping replacement, piping removal, corrosion resistant' cladding, and-heat: sink welding programs conducted'at. Pilgrim. A flaw was detected during_ inspection of one veld. : Repair was performed with veld overlay,. and that weld is classified.as IGSCC Category E. Although 93 welds have not been mitigated with any of the recommended processes, INC (hydrogen water chemistry) has been implemented ~at Pilgrim, and a UT inspection program has been developed thatLeovers all welds within the scope of GenericLLetter 88-01 except for the= inaccessible welds and the non-code related welds in' the RWCU. That program compliesLvith NRC Staff recommendations'for schedule and for methods and personnel. In addition, plans'for inaccessible welds include visual inspections-and leakage detection as recommended-by Generic Letter 88-01. Boston Edison declined to change,the Technical Specification on ISI { to include a statement that the ISI program will comply. with the. NRC s Staff positions on schedule, methods ~and personnel, and sample expansion. Rather, they proposed including'such a statement (noting ~ the proposed modifications in plans.for sample expansion) in the ISI program. This approach is specifically addressed and-. rejected in Generic Letter 88-01. Boston Edison uses Regulatory Guide 1.45 as a' guideline for any changes made to Pilgrim's Technical Specification on leakage detection. They agreed to changes in the Technical Specification'to bring it into compliance with the requirements of Generic Letter 88-01, with the possible exception of requirements for frequency of monitoring of sump [ 1evel monitoring.- Although they agreed to incorporate re'quirements into the Technical Specification for leakage monitoring, it is not-clear whether they will adhere to the guideline of 4-hour intervals-proposed by the NRC Staff or adhere to 8-hour intervals which they. previously proposed. As a result of this technical evaluation, the following recommendations are made. I 32

i. . r-a are made. (1) Rejection of Boston Edison's position pertaining ~to the portion .of the RWCU that is outboard of the.isolstion-valves. Boston Edison should extend their ISI program to those welds and-- inspect them under the' guidelines provided in Generic Letter 88-01 for IGSCC Category G welds. (2) Acceptance of Boston Edison's proposed plans <for inspection schedules and for' methods and personnel for the 238 accessible welds in code-related austenite piping systems. l (3) Rejection of Boston Edison's alternative position on sampleL j expansion. Boston Edison should include plans for sample expansion in their ISI program that comply lwith the guidelines ] contained in Generic Letter 88-01. (4) Acceptance of Boston Edison's plans for. monitoring four inaccessible welds utilizing visual-inspections'and' leakage detection. (5) Rejection. of = Boston Edison's position: concerning' changes to the Technical Specification on ISI. Boston Edison should amend q their Technical Specification to include a statement that their ISI program will comply with the NRC Staff positions on schedule, methods and personnel, and sample expansion.- (6) Acceptance of Boston' Edison's position on' leakage detection ] in the Tecca cal Specification providing that a 4-hour interval' for sump level monitoring (rather than the'8-hour interval previously proposed by Boston Edison) is incorporated along-with other changes proposed by~ Boston Edison. (7) Acceptance of the remaining portions of the Boston Edison 33 1 " - - ~ - - -~

L ,J-W .i- . e, o Submittals. 5.REFERENCESI s l 1. " Technical report on Material Selection and Processing Guidelines .for BWR Coolant Pressure Boundary Piping," NUREG 0313, Revision ~2, U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, January, 1988. .s 2. " Investigation and Evaluation of Strese-Corrosion Cracking in Piping of Light Water Reactor Plants," NUREG 0531,~ U. S. Nuclear Regulatory Commission, February. 1979. l 3. "NRC Position on IGSCC in BWR Austenitic Stainless Steel Piping," Generic Letter 88-01, U.S. Nuclear Regulatory Commission, January-N 25, 1988. l 4 Boston Edison letter dated 02/04/85 from Mr. W. Di Harrington to j Mr. D. B. Vassallo proposing a Technical Specification change ] (assigned TAC number 56835) in accordance with guidance provided ] by Generic Letter 84-11. . h 3 ~ k s . ) 14 l 1

X e; s' s s Appendix A Welds at Pilgrim within the Scope of Generic Letter 88-01 IGSCC . Pipe Dia. Caten. System -Weld Number inches Material'- Description A-RHR 10R-IA-1 18-316NG/316NG Pipe to-Tee ' A RHR 10R-IA-1A 18

316NG/316NG Pipe to Pipe; A

RRR 10R-IA.-10 ' 18 316NG/316NG Pipe to Elbow l A-RHR 10R-IA-11 18 _ ~316NG/316NG Elbow to Pipe-l~ A RHR 10R-IA-2 18 316NG/316NG Elbow'to Pipe A RHR-10R-IA-3 18 316NG/316NG Pipe to Elbow;- A RHR 10R-IA-4 18' 316NG/316NGt Elbow to Pipe A - RHR 10R -I A ~18 CF8M/316NG Valve'to Elbow A RHR-10R-IA-6 18' 316NG/316NG Pipe to Valve A RHR 10R-IA-7 18 CF8M/316NG Valve to Pipe.- A. RHR .10R-IA-8 18 316NG/CF8M Pipe to Valve. A RHR 10R-IA-9 18 316NG/316NG Elbow-to Pipe-4 A RHR 10R-IB-1 18-316NG/316NG Pipe to Tee A RHR 10R-IB-10 18 316NG/316NG Pipe to Elbow 1 A RHR 10R-IB-11 18 316NG/316NG-Elbow to Pipe A RHR 10R-IB-14 18 316NG/304-Pipe to F1d' Head A RHR 10R-IB 18. 316NG/316NG LElbow to Pipe A RHR 10R-IB-16R 18 CF8M/316NG ' Valve _to Elbow i A RHR 10R-IB-2 18 316NG/316NG Elbow to Pipe-A RHR 10R-IB-3 .18 316NG/316NG Pipe ~.to Elbow A RHk 10R-IB-4 '18 .316NG/316NG Elbow to Pipe A RHR 10R-IB-5 18 CF8M/316NG-Valve to: Elbow A

RHR, 10R-IB-6
18 316NG/CF8M' Pipe to Valve A

RHR 10R-IB-7 18 CF8M/316NG. . Valve to Pipe A RHR 10R-IB-8 18 316NG/CF8M Pipe.to Valve A RHR 10R-IB-9 18 316NG/316NG Elbow to Pipe A RHR 10R-0-1 20 - 316NG/316NG Tee to 45 Elbow i A RHR 10R-0-10 20 316NG/316NG Pipe to Pipe '1 A 'RHR 10R-0-11 20 316NG/316NG Pipe to Elbow- .A RHR 10R-0-12 20 316NG/CF8M: ' Elbow to Valve-A RHR 10R-0-13 20 ' CF8M/316NG l Valve to Pipe A RHR 10R-0-14 20 316NG/LCS Pipe to Pipe A RHR 10R-0-2 20 316NG/316NG 45 Elbow to Pipe-A RHR 10R-0-3 20 316NG/316NG ' Pipe to Elbow 3 A RHR 10R-0 20 316NG/316NG Elbow to Pipe A RHR 10R-0-5 20 316NG/316NG Pipe'to 45 Elbow A RHR 10R-0-6 20 316NG/316NG 45 Elbow to Pipe A RHR 10R-0-7 20 316NG/CF8M-Pipe to Valve A RHR 10R-0-8 20 LAS/316NG -Valve to Elbow A RHR 10R-0-9 20 316NG/316NG Elbow to Pipe

  • See page A-8 for explanation of material ebbreviations.

A-1 4

3, .o u-

.c y

~ Appendix A- (continued) - IGSCC. Pipe Dia. Description -Caten. System-W g _ eld Number inches Material' (- A RWCU 12R-0-1 6-316NG/316NGi Pipe to Swp-0-Let q A RWCU~ -12R-0-10 6 316NG/CF8M-Pipe to Valve: A-RWCU 12R-0-11 6 ~CF8M/316NG Valvb to Pipe l A. RWCU' 12R-0-12 6' 316NG/316NG Pipe to Elbow -A RWCU-12R-0-13 6= 316NG/316NG Elbow to Pipe: i A RWCU 12R-0 6 316NG/316NG Pipe to 45 Elbow i A RWCU 12R-0-15 6-316NG/316NG-45 Elbow to Pipe-. A-RWCU: 12R-0-16 6 316NG/316NG, Pipe'to Elbow i A RWCU 12R-0-17 6t 316NG/316NG Elbow to Pipe A- -RWCU-12R-0-18 6-316NG/316NG-Pipe to Elbow A RWCU 12R-0-19 6 316NG/316NG vElbow'to' Pipe A' RWCU 12R-0-19A 6-316NG/316NG' Pipe:to Elbow: c A-RWCUL 12R-0-1A 6-316NG/316NG Swp-0-Let to Elbow -i A RWCU-12R-0-2 6 316NG/316NG 45 Elbow to Pipe ' A-RWCU 12R-0-20 6' 316NG/316NG Elbow to Pipe A RWCU 12R-0-3 6 316NG/316NG Pipe to 45 Elbow A RWCU 12R-0-4 6 316NG/316NG '45 Elbow to Pipe A RWCU-12R-0-5 6 CF8M/316NG Pipe to Valve A RWCU 12R-0-6 6-CF8M/316NG Valve to Elbow. A RWCU 12R-0-7 6 316NG/316NG Elbow to Pipe i A RWCU 12R-0-8 6 316NG/316NG Pipe to Elbow A RWCU 12R-0-9 6 '316HG/316NG Elbow to Pipe 1 A RWCU 12R-0-20 6 '316NG/316NG Elbow to\\ Pipe A RWCU .12R-0-21 6 316NG/316NG' Pipe'to I?1 bow-A RWCU 12R-0-22 6 316NG/316NG. Elbow to Pipe-A CS 14-A-2 10-316NG/316NG Red to Safe End 'd A CS 14-A-3 10 316NG/LCS Red to Pipe A CS 14-A-10A '10 LCS/316NG . Valve to Pipe A CS 14-A-L 101 CF8M/LCS Red to Safe End A CS 14-B-3 10 CF8M/316NG Red.to Pipe A CS 14-b10A 10 CF8M/LCS' Valve to Pipe i A CS 14-A-11 10 316NG/CF8M Pipe to Valve 1 A CS 14-A-11A 10 316NG/316NG Pipe to Pipe: A CS 14-A-12 10 316NG/CF8M Pipe to Valve A CS 14-A-13 10 316NG/316NG-Pipe to Elbow e CS 14-A-14 10 316NG/CF8M Pipe to Valve A CS 14-A-15 10 316NG/316NG Elbow to Pipe-A CS 14-B-11 10 316NG/CF8M Pipe to Valve A CS 14-B-12 10 316NG/316NG ' Elbow to Pipe A CS 14-B-13 10 CF8M/316NG Valve to Elbow A CS 14-B-14 10 316NG/CF8M Pipe to Valve A CS 14-B-15 10 316NG/316NG Elbow to Pipe A CS 14-B-21 10 CF8M/316NG Valve to Pipe ) A-2 1 O g

v 1 e-.. L. Appendix A (continued)' I IGSCC Pipe Dia. Caten. System Weld Numbe),, inches Material Description A RPV-14-A-1 316NG/LAS Safe End'to'Noz' A RPV 14-B-1 316NG/LAS Safe End to.Noz- ) ~A RPV 2R-NIA-1 28 LAS/316NGl Noz to Safe End ) A: Recirc '2R-BP-1A 28 316NG/316NG Br Conn to Pipe A Recirc 2R-bPA-1 28 316NG/316NG Br Conn to Pipe A Recirc '2RANIA-10 28 316NG/CF8M- . Pipe to Valve ] A Recire 2R-NIA-11 28 -CF8M/316NG- ' Valve to Elbow A Recirc 2R-H1A-12 ~28 316NG/316NG-. Elbow toLPipe-A Recire '2R-NIA-13 28 316NG/316NG -Pipe to Tee A Pacirc-2R-N1A-14 28 316NG/316NG Tee to Pipe A Ncirc 2R-NIA 28 316NG/316NG. Pipe to Cross-A Recirc 2R-NIA-2 28-316NG/316NG

Pipe to Safe End.

A Recire 2R-NIA-3 28 316NG/316NG Elbow to Pipe A Recire 2R-NIA-4 28 316NG/316NG Pipe to Pipe. A-Recirc 2R-N1f-5 28 316NG/316NG Pipe to Elbow A Recirc 2R-NIA-6 28 316NG/CF8M Elbow to Valve _. A Recirc 2R-NIA-7 28 CF8M/316NGl Valve to Elbow A -Recirc 2R-NIA-7BC-1 28 316NG/316NG -Br Conn to' Elbow A Recirc 2R-NIA-7BC-2 28 316NG/316NG ~Br Conn to Elbow i-A Recirc 2R-NIA 28' 316NG/CF8M: Elbow'to Pump ~ A Recirc 2R-NIA-9 28 'CF8M/316NG -Pump to Pipe A Recire 2R-N1B-10 28 316NG/CF8M Elbow to Pump. A Recirc 2R-N1b 11 28 CF8M/316NG-Pump to Pipe A Recirc -2R-N1B-12 28 316NG/CF8M-Pipe to Valve A Recirc 2R-N1B-13 28 CF8M/316NG Valve-to Elbow A Recirc 2R-N1B-14 28 316NG/316NG-Elbow to Pipe A Recirc 2R-N1B-15 28 316NG/316NG Pipe to Tee / Cross A-Recirc 2R-N1B-2 28 316NG/316NG. Safe End to Pipe-A Recirc 2R-N1b 3 28 316NG/316NG ' Elbow to Pipe A Recirc 2R-N1B-4 28 316NG/316NG. Pipe to Tee A Recirc 2R-N1B-5 28 316NG/316NG Tee to Pipe A Recirc 2R-N1B-6 28 316NG/316NG. Pipe to Pipe-A Recire 2R-N1B-7 28 316NG/316NG Pipe to Elbow A Recirc 2R-N1B-8 28 316NG/CF8M Elbow to Valve A Recirc 2R-N1B-9 28 CF8M/316HG . Valve to Elbow A Recirc 2R-N1A-9BC-1 28 316NG/316NG Br Conn to Elbow A Recire 2R-N1A-9BC-2 28 316NG/316NG Br Conn to Elbow A-3 m-- \\

ll l a-e- i Appendix.A (continued) IGSCC Pipe Dia. Ca test. System Feld Number inches Material' _ Description i .A Recirc-2R-HA-1 22 316NG/316NGl. Header to Bend f A Recirc 2R-HA-2 22 316NG/316NG' Cross to Header i A Recirc 2R-HA-3' 22-316NG/316NG. Cross'to Header ~ jl A' Recirc' 2R-HA-41 22 316NG/316NG: Header to Bend A Recire 2R-Hb1

22

.316NG/316NG. Header to Bend-- A Recirc <2R-HB-2 22; 316NG/316NG Cross'to Header j A Recire 2R-HB-3 22 316NG/316NG Cross to Header i A -Recirc 2R-HB-4-- 22 316NG/316NG -Header to Bend A Recirc 2R-N2A-2 12 316NG/316NG - Pipe to Safe End -A .Recirc 2R-N2A-3 12 316NG/316NG - Compound Bend to Pipe A Recirc 2R-N2b2 12, 316NG/316NG-Pipe to Safe End-1 A Recirc 2R-N2B-3 12 316NG/316NG' : Header-to Pipe: -l A Recirc 2R-N2C-2 12' 316HG/316NG. Pipe to Safe End: A Recirc '2R-N2C-3 '12 316NG/316NG Cross to Pipe A Recirc 2R-N2D-2 12 316NG/316NG-Pipe to Safe End~ j A Recire 2R-N2D-3 12 316NG/316NG JHeader to Pipe j A-Recirc 2R-N2E-2 12 316NG/316NG-' Pipe to Safe End q A Rectre 2R-N2E-3 12-316NG/316NG- -Compound Bend to Pipe A 'Recire 2R-N2F-2 12 316NG/316NG Pipe to Safe End A Recirc 2R-N2F-3 12 316NG/316NG Compound Bend to Pipe j A Recire -2R-N2G-2 12 316NG/316NG Pipe to Safe End-l A Recirc 2R-N2G-3 12

316NG/316NG Header to Pipe l

A Recirc 2R-N2H-2 12- -316NG/316 NGL Pipe to Safe End A Recire 2R-N2H 12 316NG/316 NGL Cross to Pipe A Recire 2R-N2J-2 12 316NG/316NG Pipe to Safe End i A Recirc 2R-N2J-3 12 316NG/316NG-Header to Pipe A Recire 2R-N2K-2 12 316NG/316NG Pipe to Safe End A Recirc 2R-N2K-3 12 316NG/316NG Compound Bend to Pipe .l A-4

. c... a. r i t j ' ' Appendix,A (continued)' IGSCC. Pipe Dia. htm System Veld Number inches

Material, Description D

RHR-10-IA-14 18 304/304. Pipe to F1d Head D RHR 10-IA-15 18 'CF8M/304 Valve to Pipe D RHR 10R-IA-12 18 304/316NG. 'Pentrtn to Elbow-D RHR 10RLIB-12 18-304/316NG -Pentrtn to Elbow D RRR ' 10-HS-1 6 304/316' Red to Flange D RHR 10-HS-10 4 304/304 Pipe to Elbow D RHR-10-HS-11 -- 4 304/304-Pipe to Pipe 'j D RHR 10-HS-12L 4 '316/304 . Flange to Pipe D ~RHR 10-HS 4 304/316 IPipe to Flange D RHR 10-HS-14 4 304/304

Elbow to Pipe D

RHR. 10-HS 4 304/304 -Pipe to Elbow 'D .RHR- .10-HS 4 304/304 JElbow'to Pipe D-RHR 10-HS-17 4-304/304 Pipe =to Elbow D RHR 10-HS-18 4 304/304 Elbow to Pipe D RHR-10-HS-19 4 304/CF8M Valve to Elbow l u' D RHR 10-HS-2 4 304/304- -Elbow to Red D RHR 10-HS-20 4' CF8M/304- . Pipe-to Valve D RHR 10-HS-21 4 304/CF8M-Valve to Pipe D-RHR 10-HS-22 4 -CF8M/304 Elbow to Valve D RHR 10-HS-13= 4 304/304 Pipe to Elbow-D RHR 10-HS-3 4 .304/304-Pipe to Elbow-L! D RHR 10-HS-4 4. 304/304 Elbow to Pipe- 'D RHR 10-HS-5 4 304/304 Pipe to Elbow 1 D RHR 10-HS-6 4 304/304 Pipe to Pipe i D RHR 10-HS-7 4 304/304 Elbow to Pipe D RHR 10-HS-8 4 304/304 Pipe to Elbow D RHR 10-HS-9 4 304/304

Elbow to Pipe I

i u l A-5 4 y- ~

~. .a:. - s,. 4E ) 't I Appendix A (continued)' IGSCC. -Pipe Dia. Caten. System' Weld Number inches ~ Material Description l D RWCU-12-0-24. 6 304/304 -Pipe to.Pentrtn' D RWCU. 12-0-25 6

304/304 P1pe to Pipe

.1 D RWCUs 12-0-26' 61 304/304-

Pipe to Bend

D RWCUt 12-0-27 6 304/304 Bend to Pipe D RWCU' 12-0-28

6 304/304'

-Pipe to Elbow i D RWCU 12-0-29! .6. 304/304 Elbow to Pipe. l D RWCU .12-0-30 6 304/304

Pipe to ElbowL D

RWCU 0 _6 304/304 Elbow to Pipe .D RWCU .12-0-32 6-CF8M/304-P1.pe to Valve D RWCU 12R-0-23 6-316NG/304 Elbow to Pentrtn D RWCU 12-I-16 6 304/LCS Red to Pipe D RWCU 12-I-17 .4 304/304 Pipe to Red D RWCU 12-I-18 4 304/304 Elbow to Pipe, D RWCU 12-I-19 4 304/304 Pipe to Elbow D RWCU .12-I-21 4 -304/304 Pipe to Elbow D RWCU 12-I-23 4-304/304-Pipe to Elbow-D RWCU 12-I-23A-4- 304/304 Pipe to Pipe D RWCU 12-I-24 4 304/304' Elbow to Pipe D RWCU 12-I-25 4 -304/304' ' Pipe to Elbow D RWCU 12-I-25A 4 304/304- _ Pipe to Pipe-L D RWCU 12-I-26 4 304/304 Elbow to Pipe D RWCU 12-I 4 304/304 Pipe to Elbow D RWCU 12-I-28 4

304/304'

-Pipe:to Pipe D RWCU 12-I-29 -4 304/304-Pipe to Elbow-D RWCU 12-I-30 4 304/304' Elbow to Pipe D RWCU 12-I-31 4 304/304 PipeLto Elbow D RWCU 12-I-32 4 304/304 Elbow to Pipe D RWCU 12-I-33 4' 304/304- . Pipe-to Elbow D RWCU 12-I-34 4= 304/304 Elbow to Pipe D RWCU 12-I-35 ~4 304/304 . Pipe to Elbow i D RWCU 12-I-36 4 304/CF8M Valve to Pipe ~ 1 1 A-6 1 i i )

C o o-o 4.1% ( ' Appendix A (continued) IGSCC Pipe Dia. Caten. System Weld Number inches Material Description D~ CS 14-A-17 10 304/304 Pipe to Pentrtn D CS 14-A-18 10 1304/304 Pipe to Pipe D CS 14-A-19 10 CF8M/304 Valve to Pipe' D CS 14-B-17 '10 304/304 Pipe =to Pentrtn D CS 14-B-18 10 316NG/304 Elbow to Pipe-D- CS 14-B-19 10 304/316NG Pipe-to' Elbow D-CS 14-B-20 10 _ 304/304 Pipe to Pipe D, CS 14R-A 10 304/316NG Pipe;to PentrtnL D CS 14R-B-16 10 304/316NG-Pipe to Pentrtn D CS 14R-B-21A 10 304/316NG Pipe to. Pipe-D RPV 2R-N1B-1 28 LAS/316NG Noz to Safe End D- -RPV 2R-N2A-1 12 316NG/LAS Safe End'to Noz D RPV 2R-N2B-1 12- -316NG/LAS Safe End to Noz D RPV-2R-N2C-l' 12 316NG/LAS Safe End to Noz i D RPV; 2R-N2D-1 12 316NG/LAS Safe End to Noz D RPV 2R-N2E-1 12 .316NG/LAS Safe _End to Noz D RPV 2R-N2F-1 12 316NG/LAS LSafe End to Noz D RPV 2R-N2G-1 12 316NG/LAS Safe End to Noz D RPV 2R-N2H-1 12 316NG/LAS Safe.End to Noz i D RPV 2R-N2J-1 12' 316NG/LAS ' Safe'End to Noz D-RPV 2R-N2K-1. 12 316NG/LAS Safe End to Noz-1 D .RPV RPV-N9B-1 LAS/316NG 'Noz-to Safe End-4 Y i I I A-7

( ojp;c ]=* % Appendix A (continued) 1GSCC Pipe Dia. Caten.

Syster, Weld Number inches Material Description E

P5 10-IA-13A. 18 LAS/304 Noz to Safe End IGSCC Pipe-Dia. Caten. System Weld Number inches Material Description G RHR-10-IA-13A 18 304/304 Pentrtn to Flued Head" G RHR 10-IA-13A 18 304/304~ Pentrtn to j i Flued Head j G RHR 'DB/DC-10-. 18 ~ LCS/304 Pipe to Pipe 3002-3-3 _G RHR 10-F-9 18-304/CF8M- -Pipe to Valve G* RRR-DC-10-F10R '18 304/CF8M, - Pipe to Valve G RHR DB/DC 18 LCS/304 Elbow to Pipe d 3001-2-1 G RWCU 12-I-20 4 304/304' Elbow to Pipe G RWCU 12-I-22 4 304/304 Elbow to Pipe 'q r G CS DB/DC 10 LCS/304 Elbow to Pipe 3002-5-1 G CS DC-14-F31 10 ~304/CF8M -Pipe to Valve:-- i G CS DB/DC 10 304/LCS Pipe to Pipe 3001-4-1 -l G CS DC-14-F1 10 304/CF8M Pipe to Valve i G RPV 3-I-1 6 LCS/In 600-Nozzle to Cap l

  • This veld is listed as IGSCC Category D in Boston Edison Submittal No. 1.

Material Designations 304 Type 304 stainless steel 316 Type 316 stainless steel 316NG - Type 316 (nuclear grade) stainless steel Cast Stainless steel CF8M LAS Low alloy steel LCS Low carbon steel In 600 -- Inconel Alloy 600 A-8 .}}

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