ML18153A921
| ML18153A921 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 04/14/1994 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML18153A920 | List: |
| References | |
| NUDOCS 9404250020 | |
| Download: ML18153A921 (22) | |
Text
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ATTACHMENT 1 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION OF THE SECOND TEN-YEAR INTERVAL INSERVICE 'INSPECTION REQUESTS FOR RELIEF
1.0 INTRODUCTION
FOR VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION. UNITS 1 AND 2 DOCKET NUMBERS:
50-280 AND 50-281 The Technical Specifications for Surry Power Station, Units 1 and 2, state that the inservice inspection and testing of the American Society of Mechanical Engineers {ASME) Code Class 1, 2, and 3 components shall be performed in accordance with Section XI of the ASME Boiler and Pressure Vessel Code and applicable Addenda as required by 10 CFR 50.55a{g), except where specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a{g){6){i).
10 CFR 50.55a{a){3) states that alternatives to the requirements of paragraph {g) may be used, when authorized by the NRC, if
{i) the proposed alternatives would provide an acceptable level of quality and safety, or {ii) compliance with the specified requirements would result in hardship or unusual difficulties without a compensating increase in the level of quality and safety.
Pursuant to 10 CFR 50.55a{g){4), ASME Code Class 1, 2, and 3 components
{including supports) shall meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in the ASME Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," to the extent practical within the limitations of design, geometry, and materials of construction of the components.
The regulations require that inservice examination of components and system pressure tests conducted during the first ten-year interval and subsequent intervals comply with the requirements in the latest edition and addenda of Section XI of the.
ASME Code incorporated by reference in 10 CFR 50.55a{b) on the date twelve months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein.
The applicable edition of Section XI of the ASME Code for the Surry Power Station, Units 1 and 2, second IO-year inservice inspection {ISI) Interval is the 1980 Edition, through Winter 1980 Addenda.
The components {including supports) may meet the 9404250020 940414 PDR ADOCK 05000280 p
PDR i
e requirements set forth in subsequent editions and addenda_of the ASME Code incorporated by reference in 10 CFR 50.SSa(b) subject to the limitations and modifications listed therein and subject to Commission approval.
Pursuant to 10 CFR 50.SSa(g)(S), if the licensee determines that conformance with an examination requirement of Section XI of the ASME Code is not practical for its facility, information shall be submitted to the Commission in support of that determination and a request made for relief from the ASME Code requirement. After evaluation of the determination, pursuant to 10 CFR 50.55a(g)(6)(i), the Commission may grant relief and may impose alternative requirements that are determined to be authorized by law, will not endanger life, property, or the common defense and security, and are otherwise in the public interest, giving due consideration to the burden upon the licensee that could result if the requirements were imposed.
In a letter dated January 26, 1993 the licensee, Virginia Electric and Power Company proposed an alternative examination.to and requested relief from the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Section XI that it determined to be impractical to perform at the Surry Power Station, Units 1 and 2.
2.0 EVALUATION AND CONCLUSIONS The staff, with technical assistance from its contractor, the Idaho National Engineering Laboratory (INEL), has evaluated the information provided by the licensee in support of its alternative examination, and requests for relief.
Based on the information submitted, the staff adopts the contractor's conclusions and recommendations presented in the Technical Evaluation Summary attached.
Pursuant to 10 CFR 50.55a(g}(6}(i}, relief is granted for Requests for Relief SR-017, No. 24, No. 25, No. 26, and No. 27 for Unit 1, and SR-018, SR-019 and No. 23 for Unit 2.
Such relief is authorized by law and will not endanger life, property, or the common defense and security, and is otherwise in the public interest. The relief has been granted giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility.
2
e The licensee's proposed alternative examinations contained in Requests for Relief SR-015 and SR-016 {Unit 1), and SR-016 and SR-017 {Unit 2), are authorized pursuant to 10 CFR 50.55a{a){3){i).
Request for Relief No. 24 for Unit 2 will be evaluated in another NRC document.
3
ATTACHMENT 2 TECHNICAL EVALUATION
SUMMARY
OF THE SECOND TEN-YEAR INTERVAL INSERVICE INSPECTION REQUESTS FOR RELIEF
1.0 INTRODUCTION
FOR VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION, UNITS 1 AND 2 DOCKET NUMBERS:
50-280 AND 50-281 By letter dated January 26, 1993, the licensee, Virginia Electric and Power Company, requested relief from the requirements of American Society of Mechanical Engineers {ASME) Boiler and Pressure Vessel Code Section XI.
The Idaho National Engineering Laboratory {INEL) staff has evaluated the information provided by the licensee in support of these requests in the following section.
2.0 EVALUATION The information provided by the licensee in support of the request for relief has been evaluated and is documented below. Surry Power Station's second IO-year inservice inspection {ISI) interval began December 22, 1982 for Unit 1 and May 1, 1983 for Unit 2.
Based on these dates, the applicable edition of Section XI of the ASME Code for the second 10-year ISI interval for both units is the 1980 Edition through Winter 1980 Addenda {80W80).
To complete the Code-required examinations for the interval, the second IO-year ISI interval was extended by one year for both units as permitted by the Code.
~I
A.
Request for Relief Nos. SR-015 (Unit 1) and SR-016 (Unit 2), Examination Category B-L-2, Item 812.20, Visual Examination of Class 1 Reactor Coolant Pump (RCP} Internal Surfaces Code Requirement: Table IWB-2500-1, Examination Category B-L-2, Item 812.20, requires a VT-3 visual examination of the internal surfaces of Class 1 pump casings. Examinations are limited to at least one pump in each group of pumps performing similar functions in the system (e.g.,
recirculating pumps).
The visual examination may be performed on the pump selected for volumetric examination.
Licensee's Code Relief Request:
The licensee has requested relief from performing the Code-required VT-3 examinations of pump casing internal
. surfaces for at least one of the following pumps from each unit.
Unit 1 1-RC-P-lA 1-RC-P-18 1-RC-P-lC Licensee's Stated Basis for Requesting Relief:
Unit 2 2-RC-P-lA 2-RC-P-18 2-RC-P-lC "Performance of the Code required visual examination requires that the pump be disassembled to allow access to the pumps internal surfaces.
Previously this examination was scheduled in conjunction with the Code required volumetric examination on the pump casing weld, which also required pump disassembly.
Code Case N-481, Alternate Examination Requirements for Cast Austenitic Pump CasingsSection XI, Division 1, will be used in lieu of the volumetric examination required by Table IWB 2500-1, Category B-L-1 Item B12.10.
Requiring pump disassembly for the Code visual examination is impractical considering the cost and dose required to perform this action."
Licensee's Proposed Alternative Examination:
A technical evaluation of the safety and serviceability of the pump casings has been performed and separately submitted to the NRC on October 26, 1992 (Serial #92-671) as required by Code Case N-481.
The alternative inspection requirements contained in the Code Case will be implemented.
This includes 2
performance of a VT-3 visual examination of the internal surfaces whenever the pump is disassembled for maintenance.
Evaluation:
The Code of record requires a VT-3 visual examination of the internal surfaces of at least one RCP in each unit during the IO-year inspection interval. This examination requires the complete disassembly of the pump.
In lieu of this requirement, the licensee is requesting to perform the visual examination when a pump is disassembled for maintenance.
This requirement is similar to the provisions of the 1989 Edition of ASME Section XI in Table IWB-2500-1, Category B-L-2.
Disassembly of a pump for the sole purpose of visual examination is impractical due to the manpower requirements to perform the task, and the associated radiation hazards. This impracticality was recognized by the Code Committee, which eliminated the requirement to disassemble pumps for the sole purpose of performing_a visual examination (1988 Addenda and subsequent editions).
In the 1989 Edition, the VT-3 visual examination of pump casing internal surfaces is only required when the pump is disassembled for maintenance, repair, or volumetric examination. This edition of the Code has been reviewed and approved by the NRC, and referenced in the Code of Federal Regulations. Visual examination when a pump is disassembled for maintenance, as required by later editions and addenda of the Code that have been incorporated by reference into the regulations, provide and acceptable level of quality and safety.
Accordingly, it is recommended that the licensee's proposed alternative be authorized pursuant to 10 CFR 50.55a(a)(3)(i).
3
e B.
Request for Relief No. SR-016 {Unit 1) and SR-017 {Unit 2), Examination Category B-M-2, Item B12.40, Visual Examination of Class 1 Valves in the Reactor Coolant {RC), Safety Injection {SI), and Residual Heat Removal
{RHR) Systems Code Requirement:
Table IWB-2500-1, Examination Category B-M-2, Item B12.40, requires a VT-3 visual examination of valve body internal surfaces.
Examinations are limited to one valve within each group of valves that are of the same type (e.g., globe, gate, or check valve) and manufacturing method, and that are performing similar functions in the system (e.g., containment isolation and system overpressure protection).
This examination may be performed on the valve selected for volumetric examination.
Licensee's Code Relief Request:
The licensee has requested relief from performing the Code-required VT-3 visual examination on valve body internal surfaces for Class 1 valves greater than 4 inches in diameter in the RC, SI, and RHR systems.
Licensee's Stated Basis for Requesting Relief:
"The provisions to perform an ultrasonic thickness examination on valves not disassembled for maintenance, in lieu of the required visual examination, was suggested by the NRC during initial discussions held concerning relief request SR-001.
8 The extent and acceptance criteria of these alternative examinations were not discussed. Valves typically have an irregular interior and exterior surface by design. Correlating measurements with manufacturers drawings and then determining the acceptability of the measurement could only be described as "best effort." The meaningfulness of the examinations and the resultant exposure has called into question the practicality of performing these ultrasonic thickness examinations.
The 1989 Edition of ASME Section XI has eliminated the requirement to disassemble valves for examination only.
As such, under the provisions of 10 CFR 50.55a(g)4(iv), we request the use of the 1989 Edition of ASME Section XI for examinations identified in Category B-M-2, Item B12.50, for valve bodies exceeding NPS 4, and withdraw our previous relief request SR-001."
- a.
Evaluated and granted in NRC SERs dated 1/24/84 and 3/14/91.
4
e Licensee's Proposed Alternative Examination:
The subject valves will receive a VT-3 visual examination when valves are disassembled for maintenance, in accordance with Examination Category B-M-2, Item B12.50 of the 1989 Edition of the Code.
Evaluation: The Code requires a VT-3 visual examination of valve body internal surfaces. The 80W80 Code requires valves to be disassembled to perform the visual examination.
In lieu of this requirement, the licensee is requesting to use the 1989 Edition of the Code for the visual examination of Class 1 valve body internal surfaces.
In the 1989 Code, the visual examination is only required when a valve is disassembled for maintenance or other reasons. 10 CFR 50.55a(g)(4)(iv) allows the use, with NRC approval, of subsequent editions and addenda of the Code that are incorporated by reference in the Code of Federal Regulations.
The impracticality of disassembling a valve for the sole purpose of performing a visual examination was recognized by the Code Committee.
Disassembly of a valve requires many manhours of labor, with associated radiation exposure.
In addition, disassembling a valve may damage the valve.
Based on these considerations, the requirement to disassemble valves to perform a visual examination was eliminated in the 1988 Addenda (and later editions) of the Code.
Considering that the 1989 Edition of the Code has been reviewed and approved by the NRC, it is recommended that the licensee's proposed alternative be authorized pursuant to 10 CFR 50.55a(a)(3)(i). The requirements of the 1989 Edition of the Code for the visual examination of the subject valves provide an acceptable level of quality and safety.
5
e C.
Request for Relief No. SR-017 (Unit 1) and SR-019 (Unit 2), Examination Category C-G, Item C6.10, Class 2 Pump Casing Welds Code Requirement:
Table IWC-2500-1, Examination Category C-G, Item C6.10, requires a 100% surface examination, as defined by IWC-2500-8, of all the components in each piping run examined under Examination Category C-F.
In the case of multiple pumps and valves of similar design, size, and service in a system, examination of only one pump and one valve among each group of multiple pumps and valves is required.
The examination may be performed from the inside or outside surface of the component.
Licensee's Code Relief Request:
The licensee has requested relief from performing the Code-required surface examination of pump casing welds 2-01, 2-02, 2-03, and 2-04 in the following pumps in the outside recirculation spray and safety.injection systems.
Unit l l-RS-P-2A l-RS-P-2B 1-SI-P-lA 1-SI-P-lB Unit 2 2-RS-P-2A 2-RS-P-2B 2-SI-P-lA 2-SI-P-18 Licensee's Stated Basis for Requesting Relief:
"These pumps are vertical, two-stage, centrifugal pumps, with an extended shaft and casing to allow suction from the containment sump.
The motor and mechanical seals of the pumps are located at about the 12 foot elevation and the bottom of the casing at about the -30 foot elevation.
The welds identified are at the bottom of the pump casing, and are embedded within the concrete building structure. This makes the welds inaccessible from the outside.
The small diameter of the casing (24 inch O.D.) and the pump shaft prevent examination from the inside diameter."
Licensee's Proposed Alternative Examination:
The licensee stated that a remote visual examination (VT-1) of the accessible portions of the inside surface of the pump casing welds will be performed when the pumps are disassembled for maintenance or if the pump shaft is removed for maintenance.
6
D.
Evaluation:
The Code requires a surface examination of Class 2 pump casing welds from either the internal or external surface.
As stated by the licensee and supported by drawings attached to the licensee's request, the external surfaces of the subject welds are inaccessible because these welds are embedded in the concrete building structure.
In addition, the pump casing size (24 inch OD), prevents access to the inside surface. Therefore, the Code-required surface examination is impractical for these welds.
Imposition of this requirement would cause a considerable burden on the licensee because the pumps would have to be redesigned and replaced.
The licensee has proposed to perform a remote VT-1 visual examination of the inside surface when the pumps are disassembled for repair or maintenance in lieu of the Code-required surface examination.
Since degradation would most likely occur on the inside surface, the proposed examination should detect degradation that does occur and will provide reasonable assurance of the pumps' operational readiness.
Based on the impracticality of the Code requirements and the licensee's proposed examination, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g)(6)(i), provided the proposed VT-I visual examination is performed whenever a pump is disassembled for maintenance or if a pump shaft is removed for maintenance.
Request for Relief No. SR-018 (Unit 2). Examination Category B-D.
Items B3.150 and B3.160. Regenerative Heat Exchanger <RHX) Nozzle-to-Vessel Welds and Inside Radius Sections Code Requirement:
Table IWB-2500-1, Examination Category B-0, Items B3.150 and B3.160, require 100% volumetric examination as defined by Figure IWB-2500-7.
7
Licensee's Code Relief Request:
The licensee has requested relief from performing the Code-required volumetric examinations of the following nozzle-to-vessel welds and inside radius sections*on RHX 2-CH-E-3.
Welds 1-06 1-08 1-09 1-11 1-13 1-15 Inside Radius Section NIR-06 NIR-08 NIR-09 NIR-11 NIR-13 NIR-15 Licensee's Stated Basis for Requesting Relief:
"The joint design of the above nozzle welds specifies a 3" schedule 160 weldolet joined to a 9.25" O.D. x.875" thick vessel. These welds were not designed to be volumetrically examined from the outside diameter.
The configuration of the weldolet precludes axial ultrasonic examination from the nozzle side and circumferential examination in either direction.
This limits the volumetric examination to a single axial scan from the vessel side. It is our opinion that a meaningful ultrasonic examination cannot be perfor.med on the weld or inner radius with a single axial scan from the vessel side. This is due to the small diameter of the vessel and weldolet.
The change in dihedral around the joint results in a corresponding change in the ultrasonic beam angle. This makes position measurements unreliable. It would also be necessary to extend the beam path to at least two full Vee paths, which will further complicate this examination.
The limitations would substantially limit our ability to discriminate flaw indications from geometry existing around the joint.
The configuration also precludes placement of film on the outside diameter for radiography, and the inside surfaces are inaccessible. It is our opinion that the gain in assurance of component integrity from this limited examination is not commensurate with the anticipated dose expenditure.
Figures 1, 2, 3, and 4b are provided to support this request."
Licensee's Proposed Alternative Examination:
The external surfaces of the nozzle-to-vessel welds will receive a liquid penetrant surface examination.
In addition, the VT-2 visual examination will be performed during pressure testing as required by the Code.
- b.
Figures not included in this report.
8
Evaluation: The Code requires a 100% volumetric examination of all Class 1 nozzle-to-vessel welds and inside radius sections. However, the licensee has stated that the configuration of the weldolets for the RHX precludes circumferential scanning in both directions, and axial scanning from the nozzle side.
In addition, the licensee stated that the axial scan from the vessel side of the weld is unreliable because of the vessel's small diameter and the change in dihedral around the weld joint.
It is obvious from the drawings provided by the licensee that the configuration of the nozzle-to-vessel weld makes the weld and inside radius sections difficult to examine to the extent required by the Code.
This configuration precludes examination in three of the four required scanning directions and severely limits reliable coverage in the fourth.
Based on the component configuration and the dose levels that are typically associated with regenerative heat exchangers, the volumetric examination is impractical to perform.
To meet the Code requirements, the RHX nozzles would have to be redesigned and modified to allow sufficient access to the examination volumes.
This would require many man-hours of labor, cause excessive radiation exposure to personnel, and create a considerable burden on the licensee.
In lieu of the volumetric examination, the licensee proposed to perform a liquid penetrant surface examination in addition to the Code-require VT-2 visual examination during system pressure testing. This proposed examination will ensure that any significant degradation will be detected and repaired, and will provide reasonable assurance of the system's operational readiness.
Based on the impracticality due to the nozzle configuration, the potential radiation exposure associated with RHXs, and the licensee's proposed examination, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g)(6)(i).
9
E.
Request for Relief No. 24 (Unit 1) and No. 23 (Unit 2), IWD-5223, Class 3 System Hydrostatic Test of the Auxiliary Feedwater System Code Requirement: Table IWD-2500-1, Examination Category D-A, Item Dl.10, requires a system hydrostatic test as specified by IWA-5223, and a system inservice test as specified by IWA-5221.
Licensee's Code Relief Request:
The licensee has requested relief from performing the Code-required system hydrostatic test for Class 3 portions of the Auxiliary Feedwater (AFW) system between the following valves:
Valves 1-FW-145 1-FW-160 1-FW-175 2-FW-145 2-FW-160 2-FW-175 Line No.
1-WAPD-15-601 1-WAPD-17-601 l-WAPD-20-601 l-WAPD-115-601 l-WAPD-117-601 1-WAPD-120-601 10 Valves 1-FW-149 1-FW-146 1-FW-609 1-FW-163 1-FW-161 1-FW-608 1-FW-179 1-FW-176 1-FW-607 2-FW-149 2-FW-146 2-FW-609 2-FW-163 2-FW-161 2-FW-608 2-FW-179 2-FW-176 2-FW-607 Unit 1
1 1
2 2
2
Licensee's Stated Basis for Requesting Relief:
"Three pressure reducing orifices 1-FW-RO-lOOA [2-FW-RO-lOOA]c, 1-FW-R0-1008 [2-FW-R0-1008], and 1-FW-RO-lOOC [2-FW-RO-lOOC] provide during normal operation a pressure drop from approximately 1200 psig to 110 psig.
The system design takes advantage of this pressure drop by incorporating lower pressure rated piping downstream of the orifices.
However the higher pressure rated piping continues beyond the orifices for some distance. The actual pipe design pressure class change occurs at downstream check valves 1-FW-148 [2-FW-148], l-FW-163 [2-FW-163], and l-FW-178 [2-FW-178] and manual valves, l-FW-146 [2-FW-146], l-FW-161
[2-FW-161], and l-FW-176 [2-FW-176].
The check valve operation, however, does not allow separation of the lower pressure class system, when testing the higher class piping in accordance with IWD-5223.
IWD-5223 would require a test pressure of 1576 psig on the higher pressure class components in question.
The downstream connecting piping has a design pressure of 150 psig and a corresponding test pressure of only 165 psig.
As such, the connecting components would be overpressurized during the required Section XI test. The test boundary could be backed up to manual valves l-FW-147 [2-FW-147], l-FW-162 [2-FW-162], and l-FW-177 [2-FW-177]
however hydrostatically testing this test boundary would also pressurize the auxiliary feedwater pumps and their suction connection. These pumps have welded discharge connections and cannot be isolated from the test boundary due to the absence of a drain or vent valve in the area identified above.
There is a flange connection on the suction side of each pump, however using this flange for isolation purposes is considered difficult due to the piping arrangement, and susceptibility to cold spring misalignment problems. Typically centrifugal pumps are hydrostatically tested at a pressure based on the suction side of the pump described in IWA-5224[d] of the Code, which prevents any potential overpressurization concerns, or the need to use pump flanges as isolation points. The basis for relief then is two-fold.
The first impracticality is the overpressurization of the pressure reducing orifice and the design pressure class rating change.
The second impracticality is the incorporation of the auxiliary feedwater pumps into the test boundary due to the lack of vent, drain, and manual isolation valves."
Licensee's Proposed Alternative Examination:
The subject components will receive a functional test, in accordance with IWD-5222, in conjunction with the associated auxiliary feedwater pump at normal operating pressure.
Evaluation:
The Code requires a system hydrostatic test for the subject Class 3 lines.
However, because of the difference in design pressures
- c.
Unit 2 components are identified with square[] brackets.
11
and the configuration of the valves, the Code-required test pressure cannot be achieved without overpressurizing the lower pressure piping downstream.
Therefore, the Code requirement is impractical.
Imposition of the requirement would necessitate design modifications to adequately isolate the high pressure portions of the system. This would represent a considerable burden on the licensee.
In lieu of the hydrostatic test, the licensee will perform a functional test at normal operating pressure.
The subject portions of the AFW system are redundant loops fabricated from 1 inch diameter piping. Consequently, if a leak does occur, the volume will be small, because of the pipe size, and the leakage will likely be detected during the system functional test.
In addition, the impact of a potential leak on the AFW system would be reduced by system redundancy.
Based on these factors, reasonable assurance of operational readiness will be provided by the licensee's proposed examination.
Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g)(6)(i).
F.
Request for Relief No. 25 (Unit 1), Examination Category D-A, Item DI.IO, Hydrostatic Testing of Class 3 Pressure-Retaining Components Code Requirement: Table IWD-2500-1, Examination Category D-A, Item DI.IO, requires a system hydrostatic test as specified by IWD-5223, and a system inservice test as specified by IWD-5221.
IWD-5223 states that the system hydrostatic test pressure shall be at least 1.10 times the system pressure for systems with design temperatures of 200°F or less, and at least 1.25 times the system pressure for systems with design temperatures greater than 200°F.
Licensee's Code Relief Request:
The licensee has requested relief from performing the system hydrostatic test at the Code-required test pressure for piping and components between certain valves.
The licensee stated that these components and valves are:
12
--~
Valves "l-SW-499 and 2-SW-476 l-SW-317/
l-SW-327/
2-SW-337 Line#/Component 8"-WS-480-21X/
6"-WS-483-21X/
6"-WS-484-21X 1-VS-S-IA and 1-VS-S-IB" Licensee's Stated Basis for Requesting Relief:
Valves l-SW-311/
l-SW-321/
2-SW-331 l-SW-346 and 2-SW-344 "The lines and components in question are gravity fed from the in-take canal from lines providing water to both units main condensers.
Technical Specification 3.14C requires, "There shall be an operating service water flow path to and from one operating main control and emergency switchgear rooms air conditioning condenser and at least one operable service water flow path to and from at least one operable main control and emergency switchgear rooms air conditioning condenser whenever fuel is loaded in [the] reactor core."
By design there are only two supply headers and strainers associated with this common unit air conditioning system. This specification requires that the components identified always be operating or operable, while either of our two units have fuel in the reactor core.* A Technical Specification change was submitted September 4, 1992 (Serial No.92-579), to provide a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> action statement for the service water headers.
If this is approved, routine maintenance could be performed within the action statement guidelines. However, challenging the proposed action statement with a hydrostatic test (ten-year or post maintenance} is seen as excessive, potentially forcing a dual unit outage should problems occur, and impractical when compared to the proposed alternative in this low pressure system."
Licensee's Proposed Alternative Examination:
No alternative to the Code-required system hydrostatic test was proposed.
The Code-required system inservice test (IWD-5221) will be performed in conjunction with the Code-required VT-2 visual examination of accessible areas.
Evaluation:
The Code requires a system hydrostatic test for Class 3 pressure-retaining components.
Technical Specifications require that the portions of the circulating and service water components covered in this request be operable while either of the two units have fuel in the reactor core.
Performance of the hydrostatic test would require the system to be taken out of service and is therefore impractical to perform.
Imposition of the requirement would require a dual outage for 13
G.
e the sole purpose of performing a low-pressure hydrostatic test.
In lieu of this requirement, the licensee proposed to perform a system inservice test with the associated VT-2 visual examination.*
The subject piping consists of gravity-fed lines that feed water directly to the main condensers. There are no pumps to boost the pressure above the head pressure. Since these lines are essentially non-pressurized, the slight elevation in pressure will have little benefit, and any leakage that does occur should be detected by the VT-2 visual examination during the system inservice test. Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g)(6)(i). The licensee's proposed examination will provide reasonable assurance of the system's operational readiness.
Request for Relief No. 26 (Unit 1), Examination Category D-A, Item DI.IO, Hydrostatic Testing of Class 3 Pressure Retaining Components in the Circulating and Service Water System Code Requirement:
Table IWD-2500-1, Examination Category D-A, Item 01.10, requires a system hydrostatic test as specified by IWA-5223, and a system inservice test as specified by IWA-5221. IWD-5223 states that the system hydrostatic test pressure shall be at least I.IO times the system pressure for systems with design temperatures of 200°F or less, and at least 1.25 times the system pressure for systems with design temperatures greater than 200°F.
Licensee's Code Relief Request:
The licensee requested relief from performing the Code-required system hydrostatic tests of the Class 3 Circulating and Service Water System between the following valves.
The licensee stated that the required test pressure for these lines is 28 psig.
14
Valves 1-SW-MOV-102A and 1-SW-MOV-1028 LinesValves 42"-WS-13-10 and 42"-WS-12-10 Licensee's Stated Basis for Requesting Relief:
e 1-SW-37 1-SW-33 1-SW-29 1-SW-25 "The lines and components identified are gravity fed from the in-take canal from lines providing water to the main condensers. Technical Specification 3.14 requires service water flow to and from the component cooling water heat exchangers.
One unit operation requires two component cooling water heat exchangers, while two unit operation requires three component cooling water heat exchangers.
Additionally Technical Specifications 3.5 and 3.10 provide requirements associated with component cooling operability for core and residual heat removal in both unit operation and refueling modes.
The identified supply header to the component cooling water heat exchangers is the only source of cooling water to these components.
Conducting the Code required hydrostatic test would require isolation of all four component cooling water heat exchangers, placing the unit(s) in conflict with Technical Specifications as previously discussed."
Licensee's Proposed Alternative Examination:
No alternative examination was proposed.
The Code-required inservice test (IWD-5221) and associated VT-2 visual examination will be performed in lieu of the hydrostatic test.
Evaluation:
The Code requires a system hydrostatic pressure test for Class 3 pressure-retaining components.
The test pressure required by the Code for the subjects lines is 1.10 times the system pressure.
The licensee stated that the subject lines are the only source of cooling water for the Component Cooling Water Heat Exchangers (CCWHX), and that all four of the heat exchangers would have to be taken out of service to conduct the Code-required hydrostatic test. Since plant Technical Specifications require service water flow to and from the CCWHXs during operation and refueling modes, taking these lines out of service would violate Technical Specifications. Therefore, the Code requirements are impractical.
Imposition of the requirement would require a dual outage for the sole purpose of performing a low-pressure hydrostatic test.
In 15
lieu of this requirement, the licensee proposed to perform a system inservice test with the associated VT-2 visual examination.
The subject piping consists of large diameter, gravity-fed lines that feed water directly to the CCWHXs.
There are no pumps to boost the pressure above the head pressure. Since these lines are essentially non-pressurized and contain a large volume of water, the slight elevation in pressure will have little benefit, and any leakage that does occur should be obvious and easily detected by the VT-2 visual examination during the system inservice test. Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g)(6)(i). The licensee's proposed examination will provide reasonable assurance of the system's operational readiness.
H.
Request for Relief No. 27 (Unit 1), IWA-4400, Pressure Test Requirements for Repairs by Welding of Pressure Retaining Components Code Requirement:
IWA-4400(a) requires *a system hydrostatic test in accordance with IWA-5000 for repairs made by welding on the pressure retaining boundary.
Licensee's Code Relief Request:
The licensee has requested relief from performing the Code-required hydrostatic pressure testing following repair by welding for the following Class 2 systems.
Comgonent Mark#
Line No.
SIG Valve l-MS-86 4"-SHP-37-601 A
Valve l-MS-119 4"-SHP-38-601 B
Valve l-MS-117 6"-SHP-46-601 B
Valve l-MS-157 4"-SHP-39-601 C
Pipe 14"-WFPD-9-601 C
Valve l-FW-92 3
11-WAPD-13-601 C
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e Licensee's Stated Basis for Requesting Relief:
"The identified components were replaced under the rules of ASME Section XI.
IWA-4400 of the Code requires that a hydrostatic test be conducted on certain welded repairs or replacements.
These replacements cannot be hydrostatically tested without also hydrostatically testing the connecting steam generator, as no intermediate isolation exists. Valve 1-MS-117 appears to have intermediate isolation, however the main steam trip valve, 1-MS-TV-101B, acts like a check valve, and would open during pressurization of the steam generator.
"Prior to NRC and Code approval of Code Case N-416, relief requests were routinely written and approved for these type situations. The relief requests were based upon the difficulties associated with steam generator hydrostatic testing.
The test cannot be conducted at ambient conditions due to fracture prevention concerns associated with the Surry steam generators. The Surry steam generators are required to be a minimum of 150 degrees Fon the secondary side and a minimum of 180 degrees Fon the primary side, which results in difficult monitoring and controlling requirements.
Additionally normal problems, such as test boundary isolation, internal boundary leakage, placing spring hanger stops for dead weight loading concerns, and test pump size requirements further increase the difficulties associated with this particular test. The test pressure of 1356 psig also requires gagging or removal of Main Steam Safety valves, which initially lift at 1085 psig.
Some examples of previous correspondence requesting relief and approval follow:
VEPCO Letter/ Date Serial# 90-504/ 9/10/90 Serial# 88-725/ 1/9/89 Serial# 87-630/ 10/6/87 Serial # 88-725/ 1/9/89 Serial# 89-636/ 8/29/89 Serial# 87-056/ 2/13/87 Unit 1 Unit 2 NRC Letter/ Date Serial# 92-474/ 7/14/92 Serial# 89-278/ 4/7/89 Serial# 88-473/ 7/8/88 Serial# 89-278/ 4/7/89 Serial# 89-734/ 10/1/89 Serial# 88-419/ 6/17/88 "When Code Case N-416 was incorporated into Regulatory Guide 1.147,
'Inservice Inspection Code Case Acceptability-ASME Section XI Division-I', relief requests were no longer needed, since the hydrostatic test was deferred to the end of the interval hydrostatic test described in table IWC-2500-1.
This appeared to be the minimum hydrostatic testing that could be achieved for the steam generators.
Recently in Revision 9 of Regulatory Guide 1.147, you approved Code Case N-498, 'Alternative Rules for IO-Year Hydrostatic Pressure Testing for Class 1 and 2 SystemsSection XI, Division 1'. This Code Case allows testing of the Class 2 17
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steam generators at nominal operating pressure.
As a result, no hydrostatic test is now required by ASME Section XI on these components under normal circumstances, when incorporating Code Case N-498.
The hydrostatic test of Code Case N-416 is still required to be performed, however.
As described before, the components identified above can only be hydrostatically tested by additionally testing the connecting steam generator. Requiring a full steam generator test only for these replacement activities is considered impractical, due to the difficulties of the test described previously.
Licensee's Proposed Alternative Examination:
The alternative requirements described in Code Case N-416, a volumetric examination of the full penetration welds and a visual examination {VT-2} at nominal operating pressure, were previously performed and deemed acceptable.
Evaluation:
IWA-4400 requires a hydrostatic pressure test per IWA-5000 for repairs on the pressure-retaining boundary that are made by welding.
For the lines contained in this request, the licensee stated that the hydrostatic pressure test cannot be performed without pressurizing the steam generators.
The licensee also cites difficulties isolating the test boundary, test pump size requirements, concerns with placing spring hanger stops for dead weight loading, and the gagging of valves as the reason for the impracticality.
Exposing the steam generators to excess cycles can reduce their life expectancy. Therefore, the inability to isolate the steam generators from the repair area makes the Code-required hydrostatic pressure test impractical to perform.
In order to perform the system hydrostatic test, the subject system would have to be modified to provide a means of isolating the steam generators.
Imposition of this requirement on the licensee represents a significant burden.
In lieu of the system hydrostatic pressure test, the licensee performed a volumetric examination and a VT-2 visual examination during pressure testing at operating pressure. This alternative ensures the structural integrity of the repair welds and provides reasonable assurance of the 18
e e
operational readiness of the system.
Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g)(6)(i).
I.
Reguest for Relief No. 24 (Unit 2), IWA-4400, Pressure Test Reguirements for Repairs bv Welding of Pressure Retaining Components Note:
Request for Relief No. 24 (Unit 2) has been superseded by a submittal dated August 11, 1993, and therefore is evaluated in another document.
- 3. 0 CONCLUSION The INEL staff has reviewed the licensee's submittal and concludes that, pursuant to 10 CFR 50.55a(g)(6)(i), the requirements of the Code are impractical and recommends that relief be granted for Requests for Relief SR-017, No. 24, No. 25, No. 26, and No. 27 for Unit 1 and SR-018, SR-019 and No. 23 for Unit 2.
INEL recommends that for the licensee's proposed alternatives contained in Requests for Relief SR-015 and SR-016 for Unit 1, and for SR-016 and SR-017 for Unit 2, be authorized pursuant to 10 CFR 50.55a(a)(3)(i). The use of the 1989 Edition provides an acceptable level of quality and safety.
Request for Relief No. 24 for Unit 2 will be evaluated in another document.
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