NRC 2014-0022, 10 CFR 50.55a Requests Relief Requests RR-8 and RR-9 Fifth Ten-Year Lnservice Inspection Program Interval
| ML14133A365 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 05/13/2014 |
| From: | Mccartney E Point Beach |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NRC 2014-0022 | |
| Download: ML14133A365 (14) | |
Text
NEXTera ENERGY ~
POINT BEACH May 13, 2014 NRC 2014-0022 10 CFR 50.55a U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Point Beach Nuclear Plant Units 1 and 2 Dockets 50-266 and 50-301 Renewed License Nos. DPR-24 and DPR-27 10 CFR 50.55a Requests. Relief Requests RR-8 and RR-9 Fifth Ten-Year lnservice Inspection Program Interval Pursuant to 10 CFR 50.55a, "Codes and Standards," Paragraph (a)(3)(i) and Paragraph (a)(3)(ii) this letter requests that the Nuclear Regulatory Commission (NRC) grant NextEra Energy Point Beach, LLC (NextEra), relief from the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (B&PV Code),Section XI, 2007 Edition with 2008 Addenda for the Point Beach Nuclear Plant (PBNP) Units 1 and 2.
Specifically, relief is requested from the requirements of IWA-5244 for buried service water piping and buried fuel oil piping and tanks. Additionally, relief is requested from the requirements of IWD-5220, for pressure testing of emergency diesel generator Class 3 sub-systems.
Enclosures 1 and 2 contain the 10 CFR 50.55a requests, Relief Requests RR-8 and RR-9, respectively. NextEra requests approval of these requests by May 31, 2015. The requested duration of these relief requests is for the Fifth Ten-Year lnservice Inspection Interval, which commenced on August 1, 2012, and is scheduled to end on July 31, 2022, for both PBNP units.
This letter contains no new Regulatory Commitments or revisions to existing Regulatory Commitments.
If you have questions or require additional information, please contact Mr. Michael Millen, Licensing Manager, at 920/755-7845.
- Next Era Energy Point Beach, LLC, 6610 Nuclear Road, Two Rivers, WI 54241
Document Control Desk Page 2 In accordance with the provisions of 10 CFR 50.91, a copy of this submittal has been provided to the designated Wisconsin Official.
Very truly yours, NextEra Energy Point Beach, LLC Eric McCartney Site Vice-President Enclosures cc: Administrator, Region Ill, USNRC Project Manager, Point Beach Nuclear Plant, USNRC Resident Inspector, Point Beach Nuclear Plant, USNRC PSCW Mr. Mike Verhagan, Department of Commerce, State of Wisconsin
ENCLOSURE1 RELIEF REQUEST RR-8 NEXTERA ENERGY POINT BEACH POINT BEACH NUCLEAR PLANT UNITS 1 & 2 PROPOSED ALTERNATIVE IN ACCORDANCE WITH 10 CFR 50.55a(a)(3)(ii)
THAT COMPLIANCE WITH SPECIFIED REQUIREMENTS IS A HARDSHIP WITHOUT A COMPENSATING INCREASE IN THE LEVEL OF QUALITY AND SAFETY REQUEST FOR RELIEF FROM THE EXAMINATION REQUIRMENTS OF ASME SECTION XI, IWA-5244, BURIED COMPONENTS ASME Code Component(s) Affected Code Class: 3 Component Numbers: Not Applicable Examination Category: D-B Item Number(s): D2.10
==
Description:==
Approximately 90 feet of Class 3, 30-inch diameter carbon steel service water piping for both units, buried between the circulating water pumphouse and the turbine building. These sections of piping are not accessible for inspection during a pressure test.
Approximately 1000 feet of Class 3, 2-inch diameter carbon steel fuel oil piping, buried between the diesel generator building and the turbine building. Two buried fuel oil storage tanks, 35,000 gallon capacity each.
The tanks and buried sections of piping are not accessible for inspection during a pressure test.
Applicable Code Edition and Addenda
The Point Beach Nuclear Plant (PBNP) started the Fifth 10-year lnservice Inspection (lSI)
Program Interval on August 1, 2012 and is required to follow the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, "Rules for lnservice Inspection of Nuclear Power Plant Components," (ASME Section XI), 2007 Edition with the 2008 Addenda with the conditions of 10 CFR 50.55a.
Applicable Code Requirements The 2007 Edition with the 2008 Addenda of ASME Section XI contains the following requirements concerning system pressure tests for buried components:
Page 1 of 7
IWA-5244 Buried Components (a) For buried components surrounded by an annulus, the VT-2 visual examination shall consist of an examination for evidence of leakage at each end of the annulus and at low point drains.
(b) For buried components where a VT-2 visual examination cannot be performed, the examination requirement is satisfied by the following:
(1) The system pressure test for buried components that are isolable by means of valves shall consist of a test that determines the rate of pressure loss. Alternatively, the test may determine the change in flow between the ends of the buried components. The acceptable rate of pressure loss or flow shall be established by the Owner.
(2) The system pressure test for non-isolable buried components shall consist of a test to confirm that flow during operation is not impaired.
(3) Test personnel need not be qualified for VT-2 visual examination.
Table IWD-2500-1 Examination Category D-B Item Number 02.10 Parts Examined: Pressure retaining components Test Requirement: System Leakage Test (IWD-5220)
Examination Method: Visual, VT-2 Acceptance Standard: IWD-3000 Extent of Examination: Pressure retaining boundary Frequency of Inspection: Each inspection period IWD-5220 SYSTEM LEAKAGE TEST IWD-5221 Pressure The system leakage test shall be conducted at the system pressure obtained while the system, or portion of the system, is in service performing its normal operating function or at the system pressure developed during a test conducted to verify system operability (e.g., to demonstrate system safety function or satisfy technical specification surveillance requirements).
IWD-5222 Boundaries (a) The pressure-retaining boundary for closed systems includes only those portions of the system required to operate or support the safety-related function up to and including the first normally closed valve (including a safety or relief valve) or valve capable of automatic closure when the safety function is required.
(b) The pressure-retaining boundary for non-closed systems (e.g., service water systems) includes only those portions of the system required to operate or support the safety function up to and including the first normally closed valve (including a safety or relief valve) or valve capable of automatic closure when the safety function is required. Open-ended discharge piping is included in the pressure retaining boundary, provided it is periodically pressurized to conditions described in IWD-5221.
(c) The following portions of systems are excluded from examination requirements:
(1) items outside the boundaries of IWD-5222(a)
(2) items outside the boundaries of IWD-5222(b)
(3) open-ended discharge piping that is not periodically pressurized to conditions described in IWD-5221 (4) portions of systems that are associated with a spray header or are normally submerged in its process fluid such that the external surfaces of the pressure-retaining boundary are normally wetted during its pressurized conditions Page 2 of 7
Reason for the Request Service Water:
The service water (SW) system for both units is configured with a ring header such that both sides (i.e., north and south headers) of the system are supplying both units. The buried SW piping consists of two separate sections, totaling about 90 feet of 30-inch diameter carbon steel piping located between the circulating water pump house and the turbine building. These piping sections are buried approximately seven feet underground with a road built over it. There is no access to this buried piping other than excavation. No annulus was provided during original construction that would allow for testing or examination of these buried sections of piping. It is not possible to perform a direct VT-2 examination when performing a system leakage test.
IWA-5244(b) provides guidance for Buried Components where a VT-2 cannot be performed. For the buried components that are isolable by means of valves, a test that determines the rate of pressure loss is to be performed.
The two sections of buried SW piping can be isolated via six butterfly valves, three per piping section. These valves are intended to isolate a failed ring header such that the remaining portion of the ring header would still provide the required system flow; however, the valves may not provide adequate leak tightness which is necessary to accurately determine a rate of pressure loss. These butterfly valves have recently been replaced with new butterfly valves having improved leak-tightness, but there would still be no capability to validate that any pressure drop would be due to seat leakage across the valves versus through-wall leakage of the buried portions of the system. System modification would be required to perform a test in accordance with IWA-5244(b)(1), as it would be necessary to install temporary blind flanges to conduct this test. This test would create undue hardship, as it would be virtually impossible to perform the test reliably and would remove one train of service water from operation, requiring entry into a dual unit, seven-day Technical Specifications Action Condition (TSAC).
PBNP TS 3.7.8 requires, "SW ring header continuous flowpath not interrupted' for SW system operability. Removing one section of the ring header from service reduces the redundancy of the system. If the SW ring header continuous flowpath is interrupted, the ability of the system to provide required cooling water flow to required equipment must be verified within one hour in accordance with TSAC 3.7.8.C, Required Action Condition C.1. Isolating a section of the SW ring header also requires entry into a dual unit TSAC to restore the flowpath within seven days.
The 2007 Edition, 2008 Addenda, IWA-5244(b)(1), also states," Alternatively, the test may determine the change in flow between the ends of the buried components'. The SW system is not physically configured to accurately make this determination. The use of an ultrasonic flow meter would require a length of straight pipe 15 times its diameter. PBNP plant experience has shown that 15 pipe diameters of straight length piping are the minimum length required in order to get an accurate rate of flow. As-built drawings of the system show that these minimum lengths do not exist, and therefore, ultrasonic measurements would not provide the needed accuracy to determine the change in flow between the ends of the buried piping.
These buried sections of SW header are almost continuously in service. At least three SW pumps are typically running, which equates to roughly 7500 gpm through each section, or a flow velocity of approximately 3.5 fps. The probability of degradation from microbiologically influenced corrosion (MIC) is minimal in these sections of piping due to the continuous high flow rate of water through the piping (>3 fps), which does not support significant microbiological attack (Reference 1). This is corroborated by the condition of the above ground main header sections, which have been found to be in good condition and not significantly affected by MIC.
Page 3 of 7
Fuel Oil:
The diesel generator building was constructed approximately 20 years ago, to house two additional diesel generators for the site (G-03 and G-04). Included in this building are the two safety related fuel oil (FO) storage tanks, which are buried beneath the structure. The Class 3 tanks are installed with an outer leak-containment liner and leak detection capability. The Class 3 FO piping is routed underground from the diesel generator building to the two original diesel generators (G-01 and G-02) that are housed within the control building in the central area of the turbine building. The buried FO piping consists of approximately 500 feet each of two separate 2-inch lines, which are buried in a high density polyethylene (HOPE) trench (secondary containment system) along with leak detection points along its length (see sketch below). There is no access to these buried components other than excavation. No annulus was provided during original construction that would allow for testing or examination of these buried sections of piping.
Therefore, it is not possible to perform a direct VT-2 examination of the piping when performing a system leakage test.
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6' HOPE SUMP TO BE USED ONLY AT LEAK TO BE FIELD DETERMINED DETECTION POINTS DETAIL No. 1 r q5* MJ>;IAJ FTC ITYPl TYPICAL SECTION OF HOPE 1":-lENCH FOR FUEL OIL LINES SC ~L E : 7'!' = 1"*0' IWA-5244(b) provides guidance for Buried Components where a VT-2 cannot be performed. For the buried components that are isolable by means of valves, a test that determines the rate of pressure loss is to be performed.
There are isolation valves on each end of the buried sections of pipe, but pressure drop testing requires taking one of the four diesels out of service, for the duration of the test. While this does not require entry into an emergency power TSAC (assuming the applicable emergency bus is aligned to the operable diesel), it clearly reduces the redundancy of the emergency power system.
Page 4 of 7
The 2007 Edition, 2008 Addenda, IWA-5244(b)(1), also states," Alternatively, the test may determine the change in flow between the ends of the buried components". The fuel oil system is not physically configured to accurately make this determination. There are no flow instrumentation installed upstream or downstream of the buried fuel oil piping. Ultrasonic flow instruments could be used, but these instruments would not provide the needed accuracy to determine the change in flow between the ends of the buried piping to verify no leakage.
Summary For both the SW and FO buried components, performing the specified examinations or testing would require either excavating the buried components, entering potential dual unit Technical Specification Action Statement, reducing the Emergency Power system redundancy, or performing major modifications to system piping. Therefore, compliance with the specified requirements is a hardship without a compensating increase in the level of quality or safety.
Proposed Alternative and Basis for Use Proposed Alternative:
In lieu of performing a test in accordance with the requirements of IWA-5244b(1), P8NP proposes to use the requirements of IWA-5244(b)(2).
"The system pressure test for non-isolable buried components shall consist of a test to confirm that flow during operation is not impaired."
Service Water The following P8NP lnservice Testing procedures conducted on a quarterly basis will be used to verify adequate flow through the SW system during operation:
IT-07A, "P-32A Service Water Pump (Quarterly)"
IT-078, "P-328 Service Water Pump (Quarterly)"
IT-07C, "P-32C Service Water Pump (Quarterly)"
IT-070, "P-320 Service Water Pump (Quarterly)"
IT-07E, "P-32E Service Water Pump (Quarterly)"
IT-07F, "P-32F Service Water Pump (Quarterly)"
In addition, a visual examination of the ground surface areas above the buried SW piping will be performed every inspection period, at a time where no naturally occurring moisture (rain or snowmelt) has occurred that could mask indications of leakage from the buried piping. The system shall have been in operation at nominal operating conditions for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to performing the visual examinations. Since the SW system is continuously in-service and it is located in a high-traffic area (between the turbine building and the pumphouse), any leakage would be readily identified by plant personnel performing routine work activities during rounds in this area.
Fuel Oil .
The following P8NP Technical Specification Tests conducted on a monthly basis will be used to verify adequate flow through the FO system during operation:
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TS-81, Emergency Diesel Generator G-01 Monthly TS-82, Emergency Diesel Generator G-02 Monthly TS-83, Emergency Diesel Generator G-03 Monthly TS-84, Emergency Diesel Generator G-04 Monthly In addition, the installed leak detection systems on the buried tanks and buried piping leak containment trench are checked weekly by operations personnel, via PC 21 Part 4, Miscellaneous Data.
Basis for Use:
This proposed alternative will confirm unimpaired flow as stated in ASME Section XI, 2007 Edition, 2008 Addenda IWA-5244(b)(2):
"The system pressure test for non-isolable buried components shall consist of a test to confirm that flow during operation is not impaired."
Service Water:
The integrity of the buried SW piping will be verified during quarterly service water pump testing. Trending of the SW flow at a fixed differential pressure across each pump will indicate leakage through the buried piping assuming no pump degradation. The use of the inservice pump tests provides a means to ensure flow during operation is not impaired. The pump acceptance criteria also ensures the required safety flow is maintained for any buried piping leakage other than system loss of flow and pump degradation. Significant through-wall leakage of a buried pipe would result in failed inservice pump tests for three of six SW pumps providing flow to this portion of buried pipe. This failure would result in a dual unit 72-hour TSAC and lead to a plant shutdown to identify and correct the condition.
In addition, a VT-2 examination will be performed each period, for evidence of leakage on ground surfaces in the vicinity of the buried SW header, to identify potential thru -wall leakage.
Significant leakage would create a relief path through the surrounding soil to the surface, to area storm drains, or directly to the lake. Since the SW header is normally in-service, this relief path would be evident during VT-2 inspections in the vicinity of the buried piping. Prior to performing this VT-2, the system will be verified to have been in operation for the last 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and that there is no rainwater or other water runoff in the vicinity of the buried SW piping, that could mask any leakage indications. This requirement is similar to the alternative recommended in Code Case N-776 (Reference 2) for buried components, and approved in the 2011 Edition of Section XI.
The buried portions of SW piping are isolable to protect against a header break but not sufficiently isolable for a pressure-drop test. Quarterly inservice testing to ensure flow is not impaired, along with a VT-2 inspection of surface areas in the vicinity, will provide an adequate level of quality and safety as an alternative to ASM E Section XI system pressure testing.
Fuel Oil The integrity of the buried FO tanks and piping will be verified during monthly diesel generator Technical Specification testing. These monthly tests start and run each diesel, which effectively confirms that flow thru the buried portions of the FO system is not impaired.
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This is done when the day tank is filled to design capacity and demonstrates the transfer pump's ability to provide adequate makeup flow to the day tank during system operation.
During the monthly performance of TS-81, 82, 83 and 84, the inventory in the day tank is drained down to the low-level setpoint for pump actuation. The pump is verified to automatically start and allowed to replenish the day tank inventory to the high level setpoint with verification the pump automatically stops. During this process, procedure steps require recording of the percentage of tank level when the transfer pump automatically starts, as well as the percentage of tank level upon cessation of pump operation. Discharge flow rate for G01 and G02 transfer pumps is not measured during the monthly performance of TS-81 and TS-82 as there is no flow instrumentation in the pumps discharge lines to G01 and G02 day tanks. The flow rate to G01 and G02 day tanks is measured each Unit 1 refueling outage, utilizing an ultrasonic flow meter during IT-14A/B inservice testing of unloader valves F0-3982A and F0-3983A. This data provides a positive indication that pressure boundary integrity is being maintained and confirms that flow thru these lines during operation is not impaired.
Additionally, the weekly checks of the leak detection features attached to the leak containment appurtenances, surrounding both the FO tanks and piping, provide assurance that these components do not have thru-wallleakage. PC 21 Part 4 provides the procedural guidance for these weekly checks, and the historical records indicate no sign of leakage. Should leakage be identified, the condition would be entered into the site corrective action program (CAP), and appropriate actions would be taken to declare portions of the system out-of-service and affect needed repairs.
Based on the monthly Technical Specification surveillance testing, the cycle lnservice Testing, and the data collected during these tests, along with the weekly checks of the leak detection systems, PBNP considers these actions to provide an acceptable level of quality and safety as an alternative to ASME Section XI system pressure testing.
Duration of Proposed Alternative The proposed alternative will be used for the Fifth 10-Year lnservice Inspection Interval of the lnservice Inspection Program for PBNP that commenced on August 1, 2012 and is scheduled to end on July 31, 2022.
Precedents Point Beach Nuclear Plant Units 1 & 2: Fourth 10-Year Interval In service Inspection Request for Relief No. 15, Alternate Methods for Pressure Testing of Buried Components, dated September 20, 2007 (ML072480612)
Mcguire Nuclear Station, Units 1 and 2, Relief Request 09-Go-001, Regarding Alternatives from Pressure Test Requirements for Buried Piping, dated February 18, 2010 (ML100470359)
Braidwood Station, Units 1 and 2 -Relief Request 13R-02 for Pressure Testing of Buried Components, dated June 14, 2010 (ML101590696)
References
- 1) Electric Power Research Institute Technical Report NP-681 5-D, Detection and Control of Microbiological Influenced Corrosion, dated June 1, 1990
- 2) ASME Code Case N-776, Alternative to IWA-5244 Requirements for Buried Piping Page 7 of 7
ENCLOSURE 2 RELIEF REQUEST RR-9 NEXTERA ENERGY POINT BEACH POINT BEACH NUCLEAR PLANT UNITS 1 & 2 PROPOSED ALTERNATIVE IN ACCORDANCE WITH 10 CFR 50.55a(a)(3)(i)
WHICH PROVIDES AN ACCEPTABLE LEVEL OF QUALITY AND SAFETY REQUEST FOR RELIEF FROM THE REQUIREMENTS OF IWD-5220, SYSTEM LEAKAGE TESTS ASME Code Component(s) Affected Code Class: 3 Component Numbers: N/A Examination Category: D-B Item Number(s): D2.10
==
Description:==
Emergency Diesel Generator Class 3 Sub-systems; Starting Air, Glycol Cooling (G-03 and G-04 only), Fuel Oil.
Applicable Code Edition and Addenda
The Point Beach Nuclear Plant (PBNP) started the Fifth 10-year lnservice Inspection (lSI)
Program Interval on August 1, 2012 and is required to follow the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, "Rules for lnservice Inspection of Nuclear Power Plant Components," (ASME Section XI), 2007 Edition with the 2008 Addenda with the conditions of 10 CFR 50.55a.
Applicable Code Requirements The 2007 Edition with the 2008 Addenda of ASME Section XI contains the following requirements concerning system pressure tests:
Table IWD-2500-1 Examination Category D-B Item Number D2.1 0 Parts Examined: Pressure retaining components Test Requirement: System Leakage Test (IWD-5220)
Examination Method: Visual, VT-2 Acceptance Standard: IWD-3000 Extent of Examination: Pressure retaining boundary Frequency of Inspection: Each inspection period Page 1 of 5
IWD-5220 SYSTEM LEAKAGE TEST IWD-5221 Pressure The system leakage test shall be conducted at the system pressure obtained while the system, or portion of the system, is in service performing its normal operating function or at the system pressure developed during a test conducted to verify system operability (e.g., to demonstrate system safety function or satisfy technical specification surveillance requirements).
IWD-5222 Boundaries (a) The pressure-retaining boundary for closed systems includes only those portions of the system required to operate or support the safety-related function up to and including the first normally closed valve (including a safety or relief valve) or valve capable of automatic closure when the safety function is required.
(b) The pressure-retaining boundary for nonclosed systems (e.g., service water systems) includes only those portions of the system required to operate or support the safety function up to and including the first normally closed valve (including a safety or relief valve) or valve capable of automatic closure when the safety function is required.
Open -ended discharge piping is included in the pressure retaining boundary, provided it is periodically pressurized to conditions described in IWD-5221.
(c) The following portions of systems are excluded from examination requirements:
(1) items outside the boundaries of IWD-5222(a)
(2) items outside the boundaries of IWD-5222(b)
(3) open-ended discharge piping that is not periodically pressurized to conditions described in IWD-5221 (4) portions of systems that are associated with a spray header or are normally submerged in its process fluid such that the external surfaces of the pressure-retaining boundary are normally wetted during its pressurized conditions Reason for the Request Pursuant to 10 CFR 50.55a(a)(3)(i), relief is requested from the requirements of ASME Section XI , IWD-5220, System Pressure Tests, for the Emergency Diesel Generator (EDG)
Class 3 sub-systems, as all of these sub-systems are more routinely inspected and tested via existing Technical Specification Tests that ensure the operability of the EDGs.
Proposed Alternative and Basis for Use Proposed Alternative:
In lieu of performing the system pressure test on the EDG sub-systems each period, in accordance with IWD-5220 and Examination Category D-8, Item D2.1 0, PBNP proposes to use existing Technical Specification Testing of these sub-systems to demonstrate an equivalent level of quality and safety.
Basis for Use:
The following PBNP Technical Specification Testing that is conducted on a monthly basis will be used to verify appropriate leak tightness of the Class 3 sub-systems during operation of the EDGs:
TS-81, Emergency Diesel Generator G-01 Monthly TS-82, Emergency Diesel Generator G-02 Monthly TS-83, Emergency Diesel Generator G-03 Monthly TS-84, Emergency Diesel Generator G-04 Monthly Page 2 of 5
The primary intent of Technical Specification surveillance testing is slightly different from Code required examinations. Technical Specifications are intended to demonstrate component operability, whereas the system leakage and hydrostatic tests are intended to demonstrate pressure boundary integrity. There are no VT -1 visual examinations imposed on the EDG subsystems due to pressure/temperature or size exemptions as allowed IWD-1220. Therefore, verification of pressure boundary structural integrity on EDG subsystems is not included in the PBNP lSI Program. Successful EDG operability testing requires the associated subsystems to maintain pressure boundary integrity and therefore, provides an equivalent level of quality and safety to that of ASME Section XI inspections. Those auxiliary support subsystems addressed within the scope of this request for relief include the starting air system, fuel oil system, and glycol cooling system (G03 and G04 only for glycol cooling).
The repeatability of auxiliary subsystem instrumentation (pressure, level, and temperature) recorded during surveillance testing provides supporting data for the indirect verification of component integrity. Operations personnel are specifically trained in the testing of the standby EDGs and are aware of the necessity to maintain pressure boundary of the auxiliary subsystems. They are also aware of the necessity to maintain unobstructed flow characteristics for components discharging to a tank vented to atmosphere, such as the diesel fuel oil transfer pumps. Verification of component pressure boundary integrity is administratively required of personnel performing standby EDG operability testing. If evidence of leakage is identified during the test, a condition report and/or work order is initiated with corrective actions or repairs implemented and follow-up confirmatory testing is performed.
The following paragraphs provide specific procedural actions which support the use of alternative operability testing in lieu of ASME Section XI system pressure testing and VT-2 visual examination.
Starting Air Auxiliary Sub-system PBNP surveillance test procedures TS-81, 82, 83 and 84 are performed monthly to demonstrate EDG operability. As part of these procedures, pressures of both right and left bank air receivers are recorded prior to and subsequent to starting the engine with the drop in pressure verified to occur at the air start motor outlet ports. The satisfactory completion of this test demonstrates the skid-mounted air start components are properly performing their function and provides positive indication the pressure boundary integrity of the starting air subsystem is intact. In addition to the monthly testing, lnservice Test Procedures IT-100 G-01, G-02, G-03, G-04, perform quarterly reverse exercising of the right/left bank air start receivers' inlet check valves.
During the performance of this procedure, each air compressor is isolated with a vent path provided upstream of the air receiver supply check valves. Receiver pressure is observed for 15 minutes with stringent leakage criteria applied. If a through wall or otherwise excessive leak were to occur in the pressure boundary, seat leakage acceptance criteria for the check valves would be exceeded, resulting in a requirement to determine the source of the leak and repair/replacement. This data also provides a positive indication that pressure boundary integrity is being maintained for the starting air subsystem. Based on the monthly and quarterly test frequencies and the data collected during these alternative tests, PBNP considers that testing performed to satisfy the Technical Specification surveillance requirements provide an acceptable level of quality and safety as an alternative to ASME Section XI system pressure testing.
Page 3 of 5
Fuel Oil Transfer Sub-system For the fuel oil transfer subsystem, an acceptable ASME Section XI pressure test would consist of a VT -2 visual examination of the outlet piping from the day tank to the engine. This is done when the day tank is filled to design capacity and demonstrates the transfer pump's ability to provide adequate makeup flow to the day tank during system operation. During the monthly performance of TS-81, 82, 83 and 84, the inventory in the day tank is drained down to the low-level setpoint for pump actuation . The pump is verified to automatically start and allowed to replenish the day tank inventory to the high level setpoint with verification the pump automatically stops. During this process, procedure steps require recording of the percentage of tank level when the transfer pump automatically starts, as well as the percentage of tank level upon cessation of pump operation. The pump flow rate is recorded during replenishment of day tank inventory for G03 and G04 with acceptance criteria applied to recorded flow rate values.
Discharge flow rate for G01 and G02 transfer pumps is not measured during the monthly performance of TS-81 and TS-82 as there is no flow instrumentation in the pumps discharge lines to G01 and G02 day tanks. The flow rate to G01 and G02 day tanks is measured each Unit 1 refueling outage, utilizing an ultrasonic flow meter during inservice testing of unloader valves F0-3982A and F0-3983A. This data provides a positive indication that pressure boundary integrity is being maintained. Based on the Technical Specification surveillance testing frequency and the data collected during these alternative tests, PBNP considers the testing performed to satisfy the Technical Specification surveillance requirements provide an acceptable level of quality and safety as an alternative to ASME Section XI system pressure testing.
Glycol Cooling Sub-system (G03 and G04 Only)
Standby emergency diesel generators G03 and G04 are provided with a glycol cooling subsystem consisting of a coolant to air type heat exchanger. During the monthly performance of TS-83 and TS-84, coolant tank level as well as multiple point temperature indication is recorded prior to starting the engine, after 30 minutes of loaded run time, and prior to shut down, or hourly for extended runs. Normal values for all acquired data are provided in the procedure log-sheet as well as limits for the data recorded. This data provides a positive indication that pressure boundary integrity is being maintained. Based on the monthly frequency and data collected during these tests, PBNP considers the testing performed to satisfy the Technical Specification surveillance requirements provide an acceptable level of quality and safety as an alternative to ASME Section XI system pressure testing.
Summary The subject subsystems receive these tests every 30 days, which is a much more frequent testing schedule than the system pressure testing required by the Code (every 40 months). The EDGs are tested by operations personnel, who are often assisted by the plant system engineers.
The EDGs are run to test their ability to start when required and to look for any problems that may have occurred while standing idle. During the testing , the EDG systems are examined for leakage. The diesels are walked down three times each day by operations personnel. During the walkdown, operations personnel look at the appropriate water level, sump tank fuel level, starting air bank pressure, fuel oil day tank level, service water pressure, glycol expansion tank levels, and storage tanks. The operations personnel also take a general look at the diesels. If the readings are not within specifications, the Shift Manager is informed and appropriate action is initiated. Additionally, the diesels are thoroughly examined as part of routine maintenance procedures. Any significant discrepancies require the initiation of an action request and, if appropriate, a work order to correct the identified discrepancies.
Page 4 of 5
Any system leakage would be identified by the parameters monitored before a significant reduction in structural integrity of the components could occur. If evidence of leakage is identified as a result of surveillance testing, corrective actions or repairs would be implemented and a follow-up confirmatory test performed.
Technical Specification surveillance requires standby emergency diesel generators to be subject to an inspection in accordance with procedures prepared per the manufacturer's recommendation. These examinations provide added assurance the components within the starting air, fuel oil transfer, and glycol cooling subsystems demonstrate pressure boundary integrity and the ability to provide adequate flow for satisfactory standby EDG operation.
This demonstrates that the Technical Specification Testing of the EDGs will provide an acceptable level of quality and safety for the Class 3 sub-systems, as an alternative to ASME Section XI system pressure testing.
Duration of Proposed Alternative The proposed alternative will be used for the Fifth 10-Year lnservice Inspection Interval of the lnservice Inspection Program for PBNP that commenced on August 1, 2012 and is scheduled to end on July 31, 2022 Precedents Point Beach Nuclear Plant Units 1 and 2 - Evaluation of Relief Request No. 11 Associated with Emergency Diesel System VT-2 Examinations for the Fourth 10-Year Interval, dated March 21, 2003 (ML030730567)
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