ML17354A880
| ML17354A880 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 04/09/1998 |
| From: | Hovey R FLORIDA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| L-98-61, NUDOCS 9804140301 | |
| Download: ML17354A880 (15) | |
Text
CATEGORY 1 REGULA Y XNFORMATION DISTRIBUTI.
SYSTEM (RIDS)
ACCESSION NBR:9804140301 DOC.DATE: 98/04/09 NOTARIZED: NO FACIL:50-'250. Turkey Point Plant, Unit 3, Florida Power and Light C 5'-.251'-Turkey Point Plant, Unit 4, Florida Power and Light C AUTH.BEE AUTHOR AFFILIATION HOVEY,R.J.
Florida Power
& Light Co.
RECIP.NAME RECIPIENT AFFILIATXON Document Control Branch (Document Control Desk)
DOCKET 05000250 05000251
SUBJECT:
Requests relief from certain requirements of ASME Section XI Code,1989 Edition.Util requesting approval to expand applicability of Code Case N-533 from class 1 sys to class 1
&. 2 sys.
DISTRIBUTION CODE: A047D COPIES RECEIVED:LTR ENCL SIZE:
TITLE: OR Submittal: Inservice/Testing/Relief from ASME Code GL-89-04 NOTES:
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NOTE TO ALL "RIDS" RECIPIENTS:
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APR 09 t998 PIPIL L-98-61 10 CFR 50.55a U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Re:
Turkey Point Units 3 and 4 Docket Nos. 50-250 and 50-251 Inservice Inspection Program Third Ten Year Summary In accordance with 10 CFR 50.55a(a)(3), Florida Power and Light Co. (FPL) is requesting relief from certain requirements ofASME Section XICode, 1989 Edition. Revised Relief Request No.
11, "Alternative Evaluation ofLeakage,"
requests relief from ASME Section XICode, 1989 Edition, Paragraph IWA-5250(a)(2), which requires that ifleakage occurs at a bolted connection, during the conduct of a system pressure test, that all bolting be removed, VT-3 visually examined for corrosion, and evaluated in accordance with IWA-3100.
By letter L-94-118, dated May 31, 1994, FPL submitted Relief Request 11, which requested relief from removing and performing a VT-3 visual examination ofall bolting on bolted connections when leakage is observed during a system pressure test. The FPL proposed alternative examinations included the removal of the bolt closest to the source of the leakage and performing a VT-1 examination, with the results compared against the acceptance criteria ofIWB-3517.1.
Removal of the remainder of the bolting was deferred to the next time that portion of the system is out of service, but no later than the next refueling outage.
Approval of Relief Request 11 was issued by NRC letter dated March 31, 1995.
The alternatives proposed by FPL in the attached Revised Relief Request 11 allow for a systematic evaluation of the condition noted, taking into account factors such as the service age of the bolting, the bolt/component material, and the corrosiveness of the fluidin the evaluation of the degradation of the associated component and/or bolting. Ifthe evaluation concludes that the leaking condition has not degraded the bolting, no further action is necessary. Ifthe evaluation concludes that the bolting is degraded or is inconclusive in determining degradation, the bolt closest to the source of leakage shall be removed, VT-1 examined and evaluated in accordance withIWA-3100(a). When the removed bolting shows evidence of unacceptable degradation, all affected bolting shall be removed and VT-1 examined and evaluated in accordance with IWA-3100(a) or the affected bolting shall be replaced.
The Revised Relief Request 11 proposed alternatives are similar to the alternatives to the Code requirements which have been approved by the NRC on January 16, 1997 for D.C. Cook Units 1 and 2.
r+ r 9804i4030i 980409 PDR ADQCK 05000250 8
L-98-61 Page 2 In accordance with 10 CFR 50.55a, Footnote 6, and 10 CFR 50.55a(a)(3), FPL is requesting approval to expand the applicability of Code Case N-533 from class 1 systems to class 1 and 2 systems.
By letter L-97-073, dated March 13, 1997, FPL submitted a relief request for the use ofASME Code Case N-533 (Relief Request 18). Approval of the relief request for the use of Code Case N-533 was issued by NRC letter dated March 26, 1997.
Applicabilityof the currently approved Relief Request 18 is limited to class 1 connections only. The attached Revised Relief Request 18, proposes to expand the applicability of the Code Case N-533 alternatives to class 2 connections where Code compliance is determined to be impractical. The alternatives proposed include the performance of the examination of the bolted connections on systems borated for the purpose of controlling reactivity in accordance with the requirements of Code Case N-533. For class 1
systems, the insulation willbe removed from the bolted connections and a VT-2 examination performed in accordance with paragraph (b) of the Code Case each refueling outage.
For class 2 systems, this same examination willbe performed once each period as defined by the Code. The connections are not required to be pressurized during the examination and any evidence of leakage willbe evaluated in accordance with IWA-5250. In addition to these requirements, for class 1 systems borated for the purpose ofcontrolling reactivity, the system pressure test and VT-2 examination willbe performed at normal operating pressure and temperature with the insulation installed on the bolted joints, willinclude a 4-hour hold time, and willbe completed prior to returning the unit to service. For class 2 systems a functional or inservice test, as required by the Code, willbe performed with the applicable hold times prior to returning the unit to service.
These system pressure tests willbe conducted each refueling outage for class 1
systems and once each period for applicable class 2 systems.
Should there be any questions concerning this submittal, please contact us.
Very truly yours, R. J. Hovey Vice President Turkey Point Plant OIH Attachment cc:
Regional Administrator, Region II,USNRC Senior Resident Inspector, USNRC, Turkey Point Plant Project Manager, NRR, USNRC
~~-+~C
Revised Relief Request No. 11 Alternative Evaluation ofLeakage I. Component Identification:
Turkey Point Units 3 &4 Class 1, 2, and 3 Pressure Retaining Bolted Connections II. Examination Requirements:
ASME Section XICode, 1989 Edition with no addenda (the Code), paragraph IWA-5250(a)(2) requires that ifleakage occurs at a bolted connection, during the conduct ofa system pressure test, that the bolting shall be removed, VT-3 visually examined for corrosion, and evaluated in accordance withIWA-3100.
III. Relief Requested:
Florida Power and Light (FPL) requests relief&omthe Code requirement to remove and perform a VT-3 visual examination on all bolting when leakage is observed at a bolted connection during the conduct of a system pressure test.
Additionally, when required, FPL proposes to perform a VT-1 visual examination ofthe affected bolting in lieu ofthe specified VT-3 examination.
IV. Basis for Relief:
During the 1997 Unit 4 refueling outage, evidence ofleakage was identified at the 4B reactor coolant pump (RCP) flange. In the process ofperforming repairs, several bolts were required to be removed. Due to the difficultyassociated with the removal ofthese bolts, expedited reliefwas obtained to alleviate the requirement forremoval and examination ofthe remaining bolting.
Justification for this reliefwas based on the alternative examinations performed coupled with the potential for damage to the pump casing, flange and/or studs and radiation dose which would have been expended in the process ofremoval.
In some cases, removal ofany or all bolting where leakage has been observed is not the most prudent action. This requirement does not take into account factors such as the corrosiveness of the fluid, the bolting or component material, the type and location ofthe leakage, the service age ofthe bolting and the actual physical configuration ofthe bolted connection.
Additionally,in recognition ofthe burden associated with the removal and examination ofall bolting, later editions ofthe Code were revised to only require removal ofthe bolt closest to the source ofleakage.
In regards to the practicality ofperformance ofa VT-3 visual examination, ASME Section XI Code consistently references the VT-1 for examination ofpressure retaining bolting. Guidance for performance ofVT-1 examination ofbolting is already incorporated withinFPL procedures and is considered more stringent than a VT-3 examination.
V. Alternative Examinations:
As an alternative to the requirements of the 1989 Edition of the ASME Section XICode, FPL proposes that ifleakage is discovered at a bolted connection by VT-2 examination during a system pressure test, either the bolt closest to the source of leakage willbe removed and a VT-1 examination conducted and evaluated in accordance with IWA-3100(a) or an engineering evaluation willbe performed to determine the susceptibility ofthe bolting to corrosion and assess the potential for failure. The followingfactors willbe considered, as applicable, when evaluating the acceptability ofthe bolting; 1.
Service age of the bolting 2.
Bolt and component material 3.
Corrosiveness of process fluid 4.
Leakage location and system function 5.
Leakage history at the specific location 6.
Visual evidence ofcorrosion at connection (while connection is assembled) 7.
Physical configuration of the bolted connection When the evaluation of the above criteria concludes that the leaking condition has not degraded the bolting, no further action is necessary. Ifthe evaluation concludes that the bolting is degraded or is inconclusive in determining degradation, the bolt closest to the source ofleakage shall be removed, VT-1 examined and evaluated in accordance with IWA-3100(a). When the removed bolt shows evidence ofunacceptable degradation, all affected bolting shall be removed, VT-1 examined and evaluated in accordance with IWA-3100(a) or the affected bolting shall be replaced.
VI. Justification for Relief:
Removal ofpressure retaining bolting at mechanical connections for VT-1 visual examination and
'subsequent evaluation in locations where leakage has been identified is not always the most prudent action. Many bolted connections associated with pumps and valves are simply studs threaded into the body ofthe component.
Removal ofthese studs is typicaHy very difticultand time consuming, and can easily result in additional damage to the main component as a result ofthe attempts or methods ofremoval. Additionally, the areas ofthese studs expected to be affected by the leaking fluidare readily visible when the connection is disassembled and the studs are stillin place. The requirement to remove all bolting for these components, and on components when only minor leakage is noted, is a task that increases system out ofservice time and radiation exposure, and subjects the systems to a potential for internal contamination without a commensurate increase in safety or quality.
The Code requirement to remove, examine, and evaluate bolting does not allow the Owner to consider other factors which may indicate the acceptability ofthe bolted connection. FPL considers this requirement to be unnecessarily prescriptive and restrictive. The proposed alternative willallow FPL to utilize a systematic approach in the evaluation ofleakage identified at
lelted connections during the conduct ofa system pressure test. Approval ofthis alternative, in some cases, would also preclude the need for expedited relief, as was experienced recently for the 4B RCP. Based on the preceding, FPL considers the proposed alternative to provide an acceptable level ofsafety and quality.
VII. Implementation Schedule:
FPL willimplement the alternative during the Turkey Point Unit 3 &4 third 10-year inservice inspection interval.
VIII. Attachments:
None
Revised Relief Request No. 18 Use of Code Case N-533 I. Component Identification:
Turkey Point Units 3 8c 4 Class 1 and 2 pressure retaining bolted connections on systems borated for the purpose of controlling reactivity.
II. Examination Requirements:
ASME Section XICode, 1989 Edition with no addenda (the Code), paragraph IWA-5242 (a) requires that for systems borated for the purpose ofcontrolling reactivity, insulation shaH be removed &ompressure retaining bolted connection forvisual examination VT-2. Table IWB-2500-1, Category B-P, Items B15.10 through B15.71 requires VT-2inspection ofaH pressure retaining boundaries followingeach refueling outage for class 1 systems. Table IWC-2500-1, Category C-H, Items C7.10 through C7.80 requires VT-2 inspections each inspection period for class 2 systems.
III. Relief Requested:
Relief is being requested Rom performing examinations on bolted connections on systems borated for controlling reactivity during system pressure tests as prescribed by Section XICode, Article IWA-5242(a). Florida Power and Light (FPL) willutilize the alternative requirements ofASME Code Case N-533, Alternative Requirements for VT-2Visual Examination ofClass 1 Insulated Pressure Retaining Bolted Connections,Section XI,Division 1 and expand the application ofthese alternatives Rom only class 1 to class 1 and 2 systems, where compliance with the Code requirements is determined to be impracticaL IV. Basis for Relief:
The ambient conditions inside containment during the installation ofinsulation after VT-2 examinations at normal operating pressure and temperature (NOP/NOT) require heat stress work restrictions.
Containment entries at NOP/NOT are physically demanding on personnel due to the adverse heat environment.
Stay times for personnel in may areas are less than one hour and would require multiple containment entries to complete the examination activities. Ambient temperatures range Gom 95 to 110 degrees F. Personnel should not be exposed to such an adverse work environment unnecessarily without a compensating increase in the level ofquality and safety.
Additionally, the removal ofscaffolding Rom containment necessary to support such inspections, would be through the reactor containment building personnel hatch rather than the equipment hatch since the plant is above Mode 4 with the equipment hatch secured.
This wiHplace added physical and heat stress limitations on the personnel involved.
Historical data indicate that personnel contaminations increase with increasing environmental temperatures due to the profuse sweating caused by the elevated temperatures.
Reinstalling contaminated insulating material under adverse conditions, i.e., to piping that is at 2250 psia and greater than 500 degrees F would negatively impact total personnel contaminations and expose personnel to unnecessary safety risk. Additionally, increased dose would be accumulated due to reduced examination efficiency as a result ofthe necessity to wear special protective equipment, e.g., ice vest.
Examination ofthe remainder ofthe class 2 bolted connections located'outside containment would, in some cases, require the erection ofscaffolding or use ofladders in areas for which space is a premium and could jeopardize the operability ofadjacent systems or components.
Surface temperatures ofsome components to be inspected at normal operating temperatures and pressures would be in excess ofsafe contact temperatures.
The removal and reinstallation ofinsulation and scaffolding for the purpose ofperforming a VT-2inspection at operating conditions are not commensurate with good ALARApractices.
V. Alternate Examinations:
FPL willexamine bolted connections on systems borated for the purpose ofcontrolling reactivity in accordance with the requirements ofCode Case N-533. This Code Case was written specifically for class 1 systems; however, FPL requests to apply it to class 2 systems, where Code compliance is determined to be impractical.
For class 1 systems, FPL willremove the insulation Rom the bolted connections and perform a VT-2visual examination in accordance with paragraph (b) ofthe Code Case each refueling outage.
For class 2 systems, this same examination willbe performed once each period as defined by the Code. The connections are not required to be pressurized during the examination and any evidence ofleakage willbe evaluated in accordance with IWA-5250.
In addition to the requirements ofparagraph (a) ofthe Code Case, the system pressure test and VT-2examination with the insulation installed on the bolted joints at normal operating pressure and temperature willinclude a 4-hour hold time and be completed prior to returning the unit to service for class 1 systems.
For class 2 systems, functional or inservice tests willbe performed as required by the Co'de with the applicable hold times prior to returning the unit to service.
These system pressure tests willbe conducted each refueling outage for class 1 systems and once each period for applicable class 2 systems.
VI. Justification for Relief:
Code Case N-533 was approved for use by ASME on March 14, 1995, as an alternative to the Code requirements ofIWA-5242(a). The Code Case was written when it was recognized that personnel safety during the conduct ofthe VT-2 examinations would be compromised, and that examination ofbolted connections during plant shutdown would accomplish the desired results.
Approval ofa reliefrequest for utilization of Code Case N-533 at Turkey Point in regards to the examination ofclass 1 bolted connections was previously obtained under TACNOS. M98149 and M98150.
For class 1 and class 2 systems, performing a VT-2visual examination during a system pressure test as required by Code Case N-533, with the insulation in place willresult in the detection ofany significant leakage when the appropriate hold time is imposed after pressurization, prior to the VT-2 visual examination.
Furthermore, performing a VT-2visual examination after removal ofthe insulation at atmospheric or static pressure during outages, as specified by Code Case N-533, wiH detect evidence ofborated water leakage.
Borated system leakage is manifested at atmospheric conditions in the form ofboric acid residue. Evaluation ofany boric acid residue observed at low energy conditions during outages provides additional time for the evaluation ofthe leakage and planning forrepair, and is therefore a more effective and conservative method ofassuring the Code intent is met. During the course ofthese inspections, any evidence ofleakage noted willbe evaluated in accordance with IWA-5250ofthe Code.
The proposed alternative examinations presented in the Code Case willdetect any evidence of leakage, in a manner comparable to the requirements ofthe Code.
Based on the preceding, use of this Code Case provides an acceptable level ofquality and safety by the use ofan alternate method ofperforming VT-2 examinations.
VII. Implementation Schedule:
FPL willimplement ASME Code Case N-533 during the Turkey Point Units 3 8. 4 third 10-year inservice inspection interval. Ifthis Code case is published in a future revision ofRegulatory Guide 1.147, and FPL intends to continue implementation, any limitations issued in the Regulatory Guide willbe implemented.
VIII. Attachments Code Case N-533
v q
I
CASE N-533 CASES OF ASME BOILER ANDPRESSURE VESSEL CODE Approval Date: March 14,1995 See Numerical Index for expiration and any reaffirmation dates.
Case N-533 AltcrnativcRcquiremcnts for VT-2Visual Examination ofClass 1 Insulated Prcssure Retaining Bolted Connections,Section XI, Division 1 Inquiry: What alternative requirements may be used in lieu ofthose ofIWA-5242(a) to remove insulation Rom Class 1 pressure-retaining bolted connections to perform a VT-2visual examination?
Reply: It is the opinion ofthe Committee that, as an alternative to the requirements ofIWA-5242(a) to remove insulation f'rom Class 1 pressure-retaining bolted connections to perform a VT-2visual examination, the followingrequirements shall be met.
(a) A system pressure test and VT-2visual examination shall be performed each refueling outage without removal ofinsulation.
(b) Each refueling outage the insulation shall be removed Rom the bolted connection, and a VT-2visual examination shall be performed. The connection is not required to be pressurized.
Anyevidence ofleakage shall be evaluated in accordance with IWA-5250.
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