ML13239A238: Difference between revisions
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
||
Line 1: | Line 1: | ||
# | {{Adams | ||
| number = ML13239A238 | |||
| issue date = 08/20/2013 | |||
| title = Response to Request for Additional Information (RAI) Regarding Reliable Spent Fuel Pool (SFP) Instrumentation (Order No, EA-12-051) (TAC Nos. MF0737 and MF0738) | |||
| author name = Ventosa J A | |||
| author affiliation = Entergy Nuclear Northeast | |||
| addressee name = | |||
| addressee affiliation = NRC/Document Control Desk, NRC/NRR | |||
| docket = 05000247, 05000286 | |||
| license number = DPR-026, DPR-064 | |||
| contact person = | |||
| case reference number = NL-13-103, TAC MF0737, TACMF0738, EA-12-051 | |||
| document type = Letter | |||
| page count = 20 | |||
| project = TAC:MF0737, TAC:MF0738 | |||
| stage = Response to RAI | |||
}} | |||
=Text= | |||
{{#Wiki_filter:Ein SEntergy Entergy Nuclear Northeast Indian Point Energy Center 450 Broadway, GSB P.O. Box 249 Buchanan, NY 10511-0249 Tel 914 734 6700 John A. Ventosa Site Vice President Administration NL-13-103 August 20, 2013 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11545 Rockville Pike, TWFN-2 F1 Rockville, MD 20852-2738 | |||
==SUBJECT:== | |||
==REFERENCES:== | |||
Response to Request for Additional Information (RAI)Regarding Reliable Spent Fuel Pool (SFP) Instrumentation (Order No, EA-12-051) (TAC NOS. MF0737 AND MF0738)Indian Point Unit Numbers 2 and 3 Docket Nos. 50-247 and 50-286 License Nos. DPR-26 and DPR-64 NRC Order Number EA-1 2-051, Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation, dated March 12, 2012 (RA-12-038) (ML12054A682) | |||
===1.2. Entergy=== | |||
letter to NRC, Overall Integrated Plan in Response to March 12, 2012, Commission Order Modifying License With Regard To Reliable Spent Fuel Pool Instrumentation (Order No. EA-12-051), dated February 27 2013 (NL-13-043)3. NRC letter to Entergy, Request for Additional Information Regarding Reliable Spent Fuel Pool Instrumentation, Order No. EA-12-051 (TAC NOS. MF0737 AND MF0738), dated June 25, 2013, | |||
==Dear Sir or Madam:== | |||
On March 12, 2012, the NRC issued an order (Reference | |||
: 1) to Entergy Nuclear Operations, Inc (Entergy). | |||
Reference 1 required submission of an Overall Integrated Plan which was provided via Reference | |||
: 2. By Reference 3, the NRC issued a request for additional information (RAI) due within 60 days of the date of Reference 3. The attachment provides the responses to these RAIs for Indian Point Energy Center (IPEC). The RAI responses provided in Attachment 1 are based on the current preliminary design information/vendor input which is subject to change as the design is finalized. | |||
Where requested information was not available for this RAI response it will be included in the upcoming 6-month updates, as it becomes available. | |||
AocDI NL-13-103 Dockets 50-247 and 50-286 Page 2 of 2 Attachment 2 to this letter summarizes the commitment made in this response.. | |||
If you have any questions regarding this report, please contact Mr. Robert Walpole, Manager, Licensing at (914) 254-6710.I declare under penalty of perjury that the foregoing is true and correct; executed on August 20.() , 2013.Sincerely, JAV/sp Attachments: | |||
: 1. Indian Point Energy Center Response to Request for Additional Information on Reliable Spent Fuel Pool Instrumentation | |||
: 2. List of Regulatory Commitments cc: Mr. Douglas Pickett, Senior Project Manager, NRC NRR DORL Mr. William M. Dean, Regional Administrator, NRC Region I NRC Resident Inspector's Office Indian Point Ms. Bridget Frymire, New York State Department of Public Service Mr. Francis J. Murray, Jr., President and CEO, NYSERDA ATTACHMENT 1 TO NL-13-103 INDIAN POINT ENERGY CENTER RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION ON RELIABLE SPENT FUEL POOL INSTRUMENTATION ENTERGY NUCLEAR OPERATIONS, INC.INDIAN POINT NUCLEAR GENERATING UNIT NOS. 2 and 3 DOCKET NOS. 50-247 and 50-286 Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 1 of 15 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION (RAI)RAI-1 Please provide the following: | |||
a) For level 1 in both Units 2 and 3, identify the functional reasons for selection of the suction pipe identified and verify that it is the HIGHER of the two points described in the NEI 12-02 guidance for this level.b) A clearly labeled sketch depicting the elevation view of the proposed typical mounting arrangement for the portions of instrument channel consisting of permanent measurement channel equipment (e.g., fixed level sensors and/or stilling wells, and mounting brackets). | |||
Indicate on this sketch the datum values representing Level 1, Level 2, and Level 3 as well as the top of the fuel. Indicate on this sketch the portion of the level sensor measurement range that is sensitive to measurement of the fuel pool level, with respect to the Level 1, Level 2, and Level 3 datum points.RAI 1 Response: a) Level 1 is the level adequate to support operation of the normal fuel pool cooling system. It is the higher of the following two points: (1) The level at which reliable suction loss occurs due to uncovering the coolant inlet pipe or any weirs or vacuum breakers associated with suction loss.a. For the Unit 2 SFP, the elevation associated with this level is 89'-5 3/8", and corresponds to the level where the suction pipe for the Aux. Coolant System (Drawing 9321-F-2577-25, Section C-C) begins to uncover. The introduction of air into the spent fuel pit suction piping may interfere with pump performance. | |||
: b. For the Unit 3 SFP, the elevation associated with this level is 89'-5 3/8", and corresponds to the level where the suction pipe for the Aux. Coolant System (Drawing 9321-F-25773, Section C-C) begins to uncover. The introduction of air into the spent fuel pit suction piping may interfere with pump performance. | |||
(2) The level at which the normal fuel pool cooling pumps lose required NPSH assuming saturated conditions in the pool.a. For the Unit 2 SFP, the level where the spent fuel pit pumps lose required NPSH is 87'-4" for a design basis pool temperature of 200'F (Calculation FPX-0001 7).b. For the Unit 3 SFP, the level where the spent fuel pit pumps lose required NPSH is 63'-2" for a pool temperature of 212°F (Calculation CWBS-C-287). | |||
Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 2 of 15 Therefore, the Level 1 elevation is 89'-5 3/8" for both Unit 2 and Unit 3.b) The requested information is provided in Figure 1 for Indian Point Unit 2 and Figure 2 for Indian Point 3. The figures indicate Levels 1, 2, and 3 as well as the approximate location of the proposed mounting bracket incorporating the Seismic Category I attachment. | |||
The sensor is a perforated tubular coaxial waveguide that provides continuous level measurement axially and is sensitive over its entire length. These figures apply to both the primary and backup channels.The spent fuel pool (SFP) level lower instrument span or probe bottom extends down to at least three inches below the upper limit of the range of Level 3 to account for channel accuracy or instrument loop uncertainty. | |||
Therefore, the SFP level probe bottom/span extends down to at least elevation 70 feet 51/4 inches for Unit 2 and 70 feet 41/2 inches for Unit 3 (see Figures 1 and 2). The SFP level upper instrument span, at a minimum, includes normal water level high alarm. Note that Level 3 is shown in accordance with Nuclear Energy Institute (NEI) 12-02 Revision 1 guidance relative to the top of the rack;the top of the fuel is not shown.RAI-2 Please provide the following: | |||
a) The design criteria that will be used to estimate the total loading on the mounting device(s), including static weight loads and dynamic loads. Describe the methodology that will be used to estimate the total loading, inclusive of design basis maximum seismic loads and the hydrodynamic loads that could result from pool sloshing or other effects that could accompany such seismic forces.b) A description of the manner in which the level sensor (and stilling well, if appropriate) will be attached to the refueling floor and/or other support structures for each planned point of attachment of the probe assembly. | |||
Indicate in a schematic the portions of the level sensor that will serve as points of attachment for mechanical/mounting or electrical connections. | |||
c) A description of the manner by which the mechanical connections will attach the level instrument to permanent SFP structures so as to support the level sensor assembly.RAI 2 Response: a) The loading on the probe mount and probe body includes both seismic and hydrodynamic loading using seismic response spectra that bound the IPEC design basis maximum seismic loads applicable to the installation location(s). | |||
The static weight load is also accounted for in the modeling described below but is insignificant in comparison to seismic and hydrodynamic loads. Analytic modeling is being performed by the instrument vendor using Institute of Electrical and Electronic Engineers IEEE 344-2004 methodology. | |||
Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 3 of 15 The simple unibody structure of the probe assembly makes it a candidate for analytic modeling and the dimensions of the probe and complex hydrodynamic loading terms in any case preclude meaningful physical testing.A detailed computational SFP hydrodynamic model has been developed for the instrument vendor by Numerical Applications, Inc., author of the GOTHIC computational fluid dynamics code. The computational model accounts for multi-dimensional fluid motion, pool sloshing, and loss of water from the pool.Seismic loading response of the probe and mount is separately modeled using finite element modeling software. | |||
The GOTHIC-derived fluid motion profile in the pool at the installation site and resultant distributed hydrodynamic loading terms are added to the calculated seismic loading terms in the finite element model to provide a conservative estimate of the combined seismic and hydrodynamic loading terms for the probe and probe mount, specific to the chosen installation location for the probe.b) The proximal portion of the level probe is designed to be attached near its upper end (refer to vendor schematic Figure 3) to a Seismic Category I mounting bracket configured to suit the requirements of a particular SFP. The bracket may be bolted and/or welded to the SFP deck and/or SFP liner/wall according to the requirements of the particular installation per Seismic Category I requirements. | |||
c) See RAI-2.b response above.RAI-3 Please provide the following: | |||
a) A description of the specific method or combination of methods that you intend to apply to demonstrate the reliability of the permanently installed equipment under Beyond-Design-Basis (BDB) ambient temperature, humidity, shock, vibration, and radiation conditions. | |||
b) A description of the testing and/or analyses that will be conducted to provide assurance that the equipment will perform reliably under the worst-case credible design basis loading at the location where the equipment will be mounted. Include a discussion of this seismic reliability demonstration as it applies to (a) the level sensor mounted in the SFP area, and (b) any control boxes, electronics, or read-out and re-transmitting devices that will be employed to convey the level information from the level sensor to the plant operators or emergency responders. | |||
c) A description of the specific method or combination of methods that will be used to confirm the reliability of the permanently installed equipment following seismic conditions to maintain its required accuracy.RAI 3 Response: a) As stated in NEI 12-02, "Components in the area of the SFP will be designed for the temperature, humidity, and radiation levels expected during normal, event, and post-Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 4 of 15 event conditions...." Components in other areas are planned to be designed for their corresponding maximum conditions. | |||
The discussion below describes the testing and qualification intended to demonstrate equipment reliability as needed for the expected conditions associated with the SFP level channel active components (signal processor and probe assembly including vendor-supplied hard-line coaxial cable pigtail). | |||
Class 1 E nuclear-qualified interconnecting coaxial cable is planned to be utilized between the vendor-supplied probe coaxial cable pigtail and the signal processor | |||
/ display.Temperature: | |||
Signal processor: | |||
Designed for mild environment installation. | |||
Physical testing in an environmental chamber to demonstrate normal operation at the operating temperatures specified for the instrument. | |||
Probe assembly: | |||
Qualification by materials properties and use history of substantially similar probe designs in steam generator applications at significantly higher temperatures and pressures and saturated steam environments. | |||
Humidity: Signal processor: | |||
Designed for mild environment installation. | |||
Physical testing in an environmental chamber to demonstrate normal operation at the operating humidity specified for the instrument. | |||
Probe assembly: | |||
Qualification by materials properties and use history as noted above.Shock: Signal processor: | |||
Physical testing to commercial and/or military standards using shake-table and drop testing.Probe assembly: | |||
Finite element analysis in conjunction with seismic modeling described above.Vibration: | |||
Signal processor: | |||
Physical testing to applicable commercial and/or military standards using shake-table and drop testing.Probe assembly: | |||
The probe assembly and bracket together form a simple static unibody structure with intrinsic vibration resistance that is additionally subject to substantial damping due to the surrounding water medium. This is planned to be modeled using finite element modeling in conjunction with seismic modeling described above.Radiation: | |||
Signal processor: | |||
The signal processor is installed in a mild environment with radiation levels similar to background radiation, with the acknowledgement that Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 5 of 15 the radiation limit for the signal processor is similar to other commercial-grade complementary-metal-oxide-semiconductor (CMOS)-based electronics. | |||
Radiation testing is not planned. It should be noted that the instrument performs self-diagnostics before measurements are obtained and the electronics are easily accessible for periodic replacement. | |||
Probe assembly: | |||
Materials properties qualification is used.b) Signal processor (electronics): | |||
Triaxial shake-table testing is planned to be performed by the vendor to envelope seismic category 1 safe shutdown earthquake (SSE)conditions or IPEC design basis maximum seismic loads (relative to the location where the equipment is mounted) using IEEE 344-2004 methodology. | |||
Probe assembly (level sensor): Seismic and hydrodynamic finite element analysis is performed by the vendor using relevant IEEE 344-2004 methodology (using enveloping seismic category 1 SSE conditions or IPEC design basis maximum seismic loads relative to the location where the equipment is mounted), as described in the RAI-2.a response above.c) With respect to the probe assembly, combined seismic and hydrodynamic analysis will be used to demonstrate that the probe waveguide's geometric dimensions do not change significantly as a result of the seismic conditions. | |||
In the absence of alteration to the geometric configuration of the probe waveguide there is no mechanism for seismic excitation of the probe assembly to alter system accuracy.The accuracy of system electronics will be demonstrated following seismic excitation as part of the seismic testing protocol.RAI-4 Please provide the following: | |||
a) A description of how the two channels of the proposed level measurement system meet this requirement so that the potential for a common cause event to adversely affect both channels is precluded. | |||
b) Further information on how each level measurement system, consisting of level sensor electronics, cabling, and readout devices will be designed and installed to address independence through the application and selection of independent power sources, the use of physical and spatial separation, independence of signals sent to the location(s) of the readout devices, and the independence of the displays.RAI 4 Response: a) The primary instrument (Channel A) will be in the southeast corner of the SFP and the backup instrument (Channel B) will be in the northwest corner of the SFP. Locating the new instruments in the corners of the SFP takes advantage of missile and debris protection inherent in the corners. Channel A cable will be routed along the east Fuel Storage Building (FSB) wall and then along the south FSB wall to enter the Fan House, while Channel B is routed along the west FSB wall until it enters the Fan House, Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 6 of 15 maintaining physical separation in FSB. Channel A and B displays will both be located on Hydrogen Recombiner panels in each unit's Fan House. The Hydrogen Recombiner panels are designed to Seismic Category I standards. | |||
The conceptual design provides two level instruments in the Spent Fuel Pool (SFP)within the Fuel Storage Building, with cabling routed to two electronics packages mounted on Hydrogen Recombiner panels in each unit's Fan House to provide level display. Power for each channel is provided from independent existing 120V alternating current (AC), 60 Hz power sources in the general area of the electronics packages. | |||
As stated in the OIP, the primary channel will receive power from a different 480V bus than the backup channel. Backup power for each channel is provided by a separate battery capable of providing continuous display operation for at least three days. The battery power will be provided to the display/processor. | |||
The design prevents failure of a single channel from causing the alternate channel to fail.b) The design provides two identical non-safety related wide-range level instruments which feed two physically and electrically independent trains of non-safety | |||
/ seismically mounted cable and indicators to provide a highly reliable remote display of SFP water level in the Fan House. Physical separation of the two channels will be accomplished by separately routing cable and conduit as much as practical. | |||
The use of raceways (i.e.conduit or covered trays where appropriate for existing hazards) will provide additional protection from damage due to debris during a BDB event.Independent power sources are provided such that the loss of power to one channel will not result in the loss of power to the other channel. Each channel is also provided with an independent backup power source.Each display/processor in the Fan House will have a battery installed adjacent to the display enclosure which is capable of providing power for at least three days. The separation of the display is consistent with the existing plant design basis separation criteria.RAI-5 If the level measurement channels are to be powered through a battery system (either directly or through an UPS, please provide the design criteria that will be applied to size the battery in a manner that ensures, with margin, that the channel will be available to run reliably and continuously following the onset of the BDB event for the minimum duration needed, consistent with the plant FLEX Program plans.RAI 5 Response: The sample rate estimates have been developed by the vendor using conservative instrument power requirements and measured battery capacity with draw-downs during and following exposure of the batteries to their maximum operating temperature for up to seven days. The instrument configuration is planned to be established for an automated sample rate when under battery power consistent with seven days continuous operation. | |||
Permanent installed battery capacity for seven days continuous operation is planned consistent with NEI 12-02 duration without reliance on or crediting of potentially more rapid FLEX Program power restoration. | |||
Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 7 of 15 Batteries are readily replaceable via spare stock without the need for recalibration to maintain accuracy of the instrument. | |||
These measures ensure adequate power capacity and margin.RAI-6 Please provide the following: | |||
a) An estimate of the expected instrument channel accuracy performance under both (a)normal SFP level conditions (approximately Level 1 or higher) and (b) at the BDB conditions (i.e., radiation, temperature, humidity, post-seismic and post-shock conditions) that would be present if the SFP level were at the Level 2 and Level 3 datum points.b) A description of the methodology that will be used for determining the maximum allowed deviation from the instrument channel design accuracy that will be employed under normal operating conditions as an acceptance criterion for a calibration procedure to flag to operators and to technicians that the channel requires adjustment to within the normal condition design accuracy.RAI 6 Response: a) The instrument channel level accuracy will be specified as +/- 3.0 inches for all expected conditions. | |||
The expected instrument channel accuracy performance would be approximately | |||
+/-1% of span (based on the sensitive range of the detector). | |||
This is a conservative bounding instrument channel accuracy with the vendor estimating expected instrument channel accuracy is approximately one-third of the above bounding accuracy.b) In general relative to normal operating conditions, any applicable calibration procedure tolerances (or acceptance criterion) are planned to be established based on manufacturer's stated/recommended reference accuracy (or design accuracy). | |||
The methodology used is planned to be captured in plant procedures and/or programs.RAI-7 Please provide the following: | |||
a) A description of the capability and provisions the proposed level sensing equipment will have to enable periodic testing and calibration, including how this capability enables the equipment to be tested in-situ.b) A description how such testing and calibration will enable the conduct of regular channel checks of each independent channel against the other, and against any other permanently installed SFP level instrumentation. | |||
c) A description of how calibration and functional checks will be performed, and the frequency at which they will be conducted. | |||
Describe how calibration tests will be performed, and the frequency at which they will be conducted. | |||
Provide a discussion as to how these surveillances will be incorporated into the plant surveillance program. | |||
Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 8 of 15 d) A description of what preventative maintenance tasks are required to be performed during normal operation, and the planned maximum surveillance interval that is necessary to ensure that the channels are fully conditioned to accurately and reliably perform their functions when needed.RAI 7 Response: a) The level instrument automatically monitors the integrity of its level measurement system using in-situ capability. | |||
Deviation of measured test parameters from manufactured or as-installed configuration beyond a configurable threshold prompts operator intervention. | |||
Periodic calibration checks of the signal processor electronics to extrinsic National Institute of Standards and Technology (NIST)-traceable standards can be achieved through the use of standard measurement and test equipment. | |||
The probe itself is a perforated tubular coaxial waveguide with defined geometry and is not calibrated. | |||
It is planned to be periodically inspected electromagnetically using time-domain reflectometry (TDR) at the probe hardline cable connector to demonstrate that the probe assembly meets manufactured specification and visually to demonstrate that there has been no mechanical deformation or fouling.b) Each instrument electronically logs a record of measurement values over time in non-volatile memory that is compared to demonstrate constancy, including any changes in pool level, such as that associated with the normal evaporative loss/refilling cycle. The channel level measurements can be directly compared to each other (i.e., regular cross-channel comparisons). | |||
The two displays are installed in close proximity to each other, thus simplifying cross channel checks. Direct measurements of SFP level may be used for diagnostic purposes if cross-channel comparisons are anomalous. | |||
c) Performance tests (functional checks) are automated and/or semi-automated (requiring limited operator interaction) and are performed through the instrument menu software and initiated by the operator. | |||
There are a number of other internal system tests that are performed by system software on an essentially continuous basis without user intervention but which can also be performed on an on-demand basis with diagnostic output to the display for the operator to review. Other tests such as menu button tests, level alarm, and alarm relay tests are only initiated manually by the operator.Performance checks are described in detail in the Vendor Operator's Manual, and the applicable information is planned to be contained in plant operating procedures. | |||
Performance tests are planned to be performed periodically as recommended by the equipment vendor, for instance quarterly but no less often than the calibration interval of two years.Channel functional tests per operations procedures with limits established in consideration of vendor equipment specifications are planned to be performed at appropriate frequencies established equivalent to or more frequently than existing spent fuel pool instrumentation. | |||
Manual calibration tests are as described above in RAI-7.a and b. | |||
Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 9 of 15 Manual calibration and operator performance checks are planned to be performed in a periodic scheduled fashion with additional maintenance on an as-needed basis when flagged by the system's automated diagnostic testing features.Channel calibration tests per maintenance procedures with limits established in consideration of vendor equipment specifications are planned to be performed at frequencies established in consideration of vendor recommendations. | |||
d) Periodic (e.g., quarterly or monthly) review of the system level history and log files and routine attention to any warning message on the system display is recommended by the vendor. Formal calibration checks are recommended by the vendor on a two-year interval to demonstrate calibration to external NIST-traceable standards. | |||
Formal calibration check surveillance interval and timing would be established consistent with applicable guidance [i.e., NEI 12-02 Section 4.3; on a refueling outage interval basis and within 60 days of a planned refueling outage]. Items such as system batteries are planned to be assessed under the Preventive Maintenance (PM) program for establishment of replacement frequency. | |||
Surveillance/PM timing/performance are planned to be controlled via tasks in the PM program.RAI-8 Please provide the following: | |||
a) Since the "credited" primary and backup display location is other than the main control room, provide justification for prompt accessibility to displays including primary and alternate route evaluation, habitability at display location(s), continual resource availability for personnel responsible to promptly read displays, and provisions for communications with decision makers for the various SFP drain down scenarios and external events.b) The reasons justifying why the locations selected enable the information from these instruments to be considered "promptly accessible" to various drain-down scenarios and external events.c) Describe how the reliability of the "remote" display addresses the criteria in the Order and the guidance in NEI 12-02. Identify any deviations from that guidance.RAI 8 Response: a) The current design entails mounting both the primary and backup displays in the Fan House Building. | |||
The Overall Integrated Plan will be updated to reflect this change. The following attributes apply to the display of SFP water level in the Fan House: Accessibility Information from the accessibility evaluation is scheduled to be included in the six-month update due on February 27, 2014.Habitability Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 10 of 15 Information from the habitability evaluation is scheduled to be included in the six-month update due on February 27, 2014.Resource Availability The FLEX staffing plan is currently scheduled for completion in December 2013. The information from the FLEX staffing plan is scheduled to be included in the six-month update due on February 27, 2014.Communications Portable radios will be used to transmit the SFP water level to key decision makers.b) Information from the accessibility evaluation is scheduled to be included in the six-month update due on February 27, 2014.c) The current design no longer employs the use of a remote display. The OIP will be updated to reflect this change.RAI-9 Please provide a description of the standards, guidelines and/or criteria that will be utilized to develop procedures for inspection, maintenance, repair, operation, abnormal response, and administrative controls associated with the SFP level instrumentation, as well as storage and installation of portable instruments. | |||
RAI 9 Response: Vendor recommended inspection, maintenance, and repair procedures for the liquid level measurement system have been developed through the vendor's 30-year experience developing and manufacturing liquid level measurement and cable testing instrumentation. | |||
These are for the most part specific to the system's proprietary electronics, subject to relevant industry standards for electronics fabrication and inspection and vendor's quality management system.Where relevant, standards for naval shipboard liquid level indicating equipment have been used to develop procedures for operation, abnormal response, and administrative controls.. | |||
Portable instrumentation is not utilized. | |||
Both primary and backup SFPI channels incorporate permanent hard-wired installation. | |||
The specific procedures to be used to capture the required activities described in this RAI response have not yet been developed but are planned to be developed in accordance with the vendor recommendations and Entergy processes and procedures. | |||
0 Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 11 of 15 RAI-10 Please provide the following: | |||
a) Further information describing the maintenance and testing program the licensee will establish and implement to ensure that regular testing and calibration is performed and verified by inspection and audit to demonstrate conformance with design and system readiness requirements. | |||
Include a description of your plans for ensuring that necessary channel checks, functional tests, periodic calibration, and maintenance will be conducted for the level measurement system and its supporting equipment. | |||
b) A description of how the guidance in NEI 12-02 section 4.3 regarding compensatory actions for one or both non-functioning channels will be addressed. | |||
d) A description of what compensatory actions are planned in the event that one of the instrument channels cannot be restored to functional status within 90 days.RAI 10 Response: a) See RAI-6, 7, and 9 responses above for related descriptions of associated maintenance and testing program details. SFPI channel/equipment maintenance/preventative maintenance and testing program requirements to ensure design and system readiness are planned to be established in accordance with Entergy's processes and procedures and in consideration of vendor recommendations to ensure that appropriate regular testing, channel checks, functional tests, periodic calibration, and maintenance is performed. | |||
Subject maintenance and testing program requirements are planned to be developed during the SFPI modification design process.b) Both primary and backup SFPI channels incorporate permanent installation (with no reliance on portable, post-event installation) of relatively simple and robust augmented quality equipment. | |||
Permanent installation coupled with stocking of adequate spare parts reasonably diminishes the likelihood that a single channel (and greatly diminishes the likelihood that both channels) is (are) out-of-service for an extended period of time.Planned compensatory actions for unlikely extended out-of-service events are summarized as follows:#l Compensatory Action if Required Channel(s) | |||
Required Restoration Action Restoration Action not completed Out-of- within Specified Time Restore channel to functional Immediately initiate action in status within 90 days (or if channel accordance with Note below.1 restoration not expected within 90 days, then proceed to-Compensatory Action).Initiate action within 24 hours to Immediately initiate action in 2 restore one channel to functional accordance with Note below.status, and restore one channel to Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 12 of 15# Compensatory Action if Required Channel(s) | |||
Required Restoration Action Restoration Action not completed Out-of- within Specified Time Service functional status within 72 hours.Note: Present a report to the on-site safety review committee within the following 14 days. The report shall outline the planned alternate method of monitoring, the cause of the non-functionality, and the plans and schedule for restoring the instrumentation channel(s) to functional status.c) The requested information is provided in the RAI-10.b response. | |||
Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 13 of 15 POOL LEVELS AND REFERENCES MOUNTING BRACKET ELF VA11ON.. .L ....9'0 II--..-F- -E ---- ------ ---- ----- ---- --- -- ---. 94'-3 "... ... .. nO_. D-. L) ... .93'-B" I-------------- | |||
.L M ------------- | |||
------------- | |||
93'-31-S 3-1 --------------- | |||
9-------------- | |||
92"-2----------- | |||
Y & S,. M MQtt G ------------- | |||
---- _$.PL1*U 1_ -.... 89'-5 W9'" 111 111111111111111 1 801-8 14"...... ...-- -- -- --1 T ---LE -- ---L- ---- ---- ---- --- 70"-5 114"-- -- -- --PV UW -- -- ----.-- --- --. 69'-8 1/4" BOTTOM OF POOL LEVEL REFERENCE 9321-F-2514-19 FSB General Arrangement Plans & Elev.2-ARP-SGF (Alarm Response Procedure) | |||
& 9321-F-7043 9321-F-2514-19 FSB General Arrangement Plans & Elev: 9321-F-7043 (LC-650 in Section B-B)2-ARP-SGF (Alarm Response Procedure) | |||
& 9321-F-7043 TS 3.7.11 Spent Fuel Pit Level 9321-F-2577. | |||
FSB Aux Coolant System Sections, Section C-C NEI 12-02 (Level 3 + 10')Bottom Minr Sensitive Range, 3' below LEVEL 3 upper limit 9321-F-1388 | |||
& HOLTEC #397 to 408 9321-F-2514-19 FSB General Arrangement Plans & Elev.54.'-7 I I FIGURE 1 (Unit 2 SFP Elevation View with Levels Indicated) | |||
Figure 1 Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 14 of 15 POOL LEVELS AND REFERENCES MOiJNTIN3 BRACKET ELEVATION MIE. ..95 ..0.-..- ------------ ....94'-2"--.. .... ----n A V ------- ---------------- | |||
---- ------ -93'-8".... .------- --- -------- ------ ------ --- --- -93'-2" | |||
-- ..- 91 '--8--FP-- -C T 2----PIPNG | |||
_ ----------------- | |||
----- F_.LEL 89-5 31W'8 SENSOR----------------------- | |||
--------- | |||
..... 80'-7 112"-.-........ | |||
--TF- ---L- ---ff.L ... -, L -------------- | |||
70'-7 1/2"------------------------- | |||
---------------- | |||
70U-4 1/2"-.-.....- | |||
..- ..- 1PJ BV" L --_ 69'-7 1/2'0 1L LEVE11111111 I BOTTOM OF POOL LEVEL REFERENCE 9321-F-20277 RO Fuel Storage Building El. 95'-0" Plans, Sections and Details Mechanical 3-ARP-013 (Alarm Response Procedure) | |||
& 9321-F-70433 9321-F-20277 RO Fuel Storage Building El. 95'-0" Plans, Sections and Details Mechanical 9321-F-70443 (LC-650 In Section B-B)3-ARP-013 (Alarm Response Procedure) | |||
& 9321-F-70433 TS 3.7.14 Spent Fuel Pit Level 9321-F-25773, FSB Aux Coolant System Sections (Plan Z', Section C-C)NEI 12-02 (Level 3 + 10')Bottom MIn. Sensitive Range, 3" below LEVEL 3 upper limit IP3V-1684-0004, IP3V-1684-00032 9321-C-1 1023 RI Proposed FSB Mat. Pre-Permit Const.I I ---54'-7'FIGURE 2 (Unit 3 SFP Elevation View with Levels Indicated) | |||
Figure 2 Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 15 of 15 , CABLE ,,-PROBE HEAD FLANGE MOUNT Figure 3 ATTACHMENT 2 TO NL-1 3-103 LIST OF REGULATORY COMMITTMENTS ENTERGY NUCLEAR OPERATIONS, INC.INDIAN POINT NUCLEAR GENERATING UNIT NOS. 2 and 3 DOCKET NOS. 50-247 and 50-286 Attachment 2 NL-13-103 Dockets 50-247 and 50-286 Page 1 of 1 List of Regulatory Commitments The following table identifies those actions committed to by Entergy in this document. | |||
Any other statements in this submittal are provided for information purposes and are not considered to be regulatory commitments. | |||
TYPE (Check One) SCHEDULED COMPLETION COMMITMENT ONE- CONTINUING DATE TIME COMPLIANC (I TE ACTION E (If Required)Where requested information was not available for this RAI response in NL Six month intervals 103 it will be included in the upcoming 6-month updates, as it becomes available.}} |
Revision as of 20:17, 17 March 2019
ML13239A238 | |
Person / Time | |
---|---|
Site: | Indian Point ![]() |
Issue date: | 08/20/2013 |
From: | Ventosa J A Entergy Nuclear Northeast |
To: | Document Control Desk, Office of Nuclear Reactor Regulation |
References | |
NL-13-103, TAC MF0737, TACMF0738, EA-12-051 | |
Download: ML13239A238 (20) | |
Text
Ein SEntergy Entergy Nuclear Northeast Indian Point Energy Center 450 Broadway, GSB P.O. Box 249 Buchanan, NY 10511-0249 Tel 914 734 6700 John A. Ventosa Site Vice President Administration NL-13-103 August 20, 2013 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11545 Rockville Pike, TWFN-2 F1 Rockville, MD 20852-2738
SUBJECT:
REFERENCES:
Response to Request for Additional Information (RAI)Regarding Reliable Spent Fuel Pool (SFP) Instrumentation (Order No, EA-12-051) (TAC NOS. MF0737 AND MF0738)Indian Point Unit Numbers 2 and 3 Docket Nos. 50-247 and 50-286 License Nos. DPR-26 and DPR-64 NRC Order Number EA-1 2-051, Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation, dated March 12, 2012 (RA-12-038) (ML12054A682)
1.2. Entergy
letter to NRC, Overall Integrated Plan in Response to March 12, 2012, Commission Order Modifying License With Regard To Reliable Spent Fuel Pool Instrumentation (Order No. EA-12-051), dated February 27 2013 (NL-13-043)3. NRC letter to Entergy, Request for Additional Information Regarding Reliable Spent Fuel Pool Instrumentation, Order No. EA-12-051 (TAC NOS. MF0737 AND MF0738), dated June 25, 2013,
Dear Sir or Madam:
On March 12, 2012, the NRC issued an order (Reference
- 1) to Entergy Nuclear Operations, Inc (Entergy).
Reference 1 required submission of an Overall Integrated Plan which was provided via Reference
- 2. By Reference 3, the NRC issued a request for additional information (RAI) due within 60 days of the date of Reference 3. The attachment provides the responses to these RAIs for Indian Point Energy Center (IPEC). The RAI responses provided in Attachment 1 are based on the current preliminary design information/vendor input which is subject to change as the design is finalized.
Where requested information was not available for this RAI response it will be included in the upcoming 6-month updates, as it becomes available.
AocDI NL-13-103 Dockets 50-247 and 50-286 Page 2 of 2 Attachment 2 to this letter summarizes the commitment made in this response..
If you have any questions regarding this report, please contact Mr. Robert Walpole, Manager, Licensing at (914) 254-6710.I declare under penalty of perjury that the foregoing is true and correct; executed on August 20.() , 2013.Sincerely, JAV/sp Attachments:
- 1. Indian Point Energy Center Response to Request for Additional Information on Reliable Spent Fuel Pool Instrumentation
- 2. List of Regulatory Commitments cc: Mr. Douglas Pickett, Senior Project Manager, NRC NRR DORL Mr. William M. Dean, Regional Administrator, NRC Region I NRC Resident Inspector's Office Indian Point Ms. Bridget Frymire, New York State Department of Public Service Mr. Francis J. Murray, Jr., President and CEO, NYSERDA ATTACHMENT 1 TO NL-13-103 INDIAN POINT ENERGY CENTER RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION ON RELIABLE SPENT FUEL POOL INSTRUMENTATION ENTERGY NUCLEAR OPERATIONS, INC.INDIAN POINT NUCLEAR GENERATING UNIT NOS. 2 and 3 DOCKET NOS. 50-247 and 50-286 Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 1 of 15 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION (RAI)RAI-1 Please provide the following:
a) For level 1 in both Units 2 and 3, identify the functional reasons for selection of the suction pipe identified and verify that it is the HIGHER of the two points described in the NEI 12-02 guidance for this level.b) A clearly labeled sketch depicting the elevation view of the proposed typical mounting arrangement for the portions of instrument channel consisting of permanent measurement channel equipment (e.g., fixed level sensors and/or stilling wells, and mounting brackets).
Indicate on this sketch the datum values representing Level 1, Level 2, and Level 3 as well as the top of the fuel. Indicate on this sketch the portion of the level sensor measurement range that is sensitive to measurement of the fuel pool level, with respect to the Level 1, Level 2, and Level 3 datum points.RAI 1 Response: a) Level 1 is the level adequate to support operation of the normal fuel pool cooling system. It is the higher of the following two points: (1) The level at which reliable suction loss occurs due to uncovering the coolant inlet pipe or any weirs or vacuum breakers associated with suction loss.a. For the Unit 2 SFP, the elevation associated with this level is 89'-5 3/8", and corresponds to the level where the suction pipe for the Aux. Coolant System (Drawing 9321-F-2577-25, Section C-C) begins to uncover. The introduction of air into the spent fuel pit suction piping may interfere with pump performance.
- b. For the Unit 3 SFP, the elevation associated with this level is 89'-5 3/8", and corresponds to the level where the suction pipe for the Aux. Coolant System (Drawing 9321-F-25773, Section C-C) begins to uncover. The introduction of air into the spent fuel pit suction piping may interfere with pump performance.
(2) The level at which the normal fuel pool cooling pumps lose required NPSH assuming saturated conditions in the pool.a. For the Unit 2 SFP, the level where the spent fuel pit pumps lose required NPSH is 87'-4" for a design basis pool temperature of 200'F (Calculation FPX-0001 7).b. For the Unit 3 SFP, the level where the spent fuel pit pumps lose required NPSH is 63'-2" for a pool temperature of 212°F (Calculation CWBS-C-287).
Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 2 of 15 Therefore, the Level 1 elevation is 89'-5 3/8" for both Unit 2 and Unit 3.b) The requested information is provided in Figure 1 for Indian Point Unit 2 and Figure 2 for Indian Point 3. The figures indicate Levels 1, 2, and 3 as well as the approximate location of the proposed mounting bracket incorporating the Seismic Category I attachment.
The sensor is a perforated tubular coaxial waveguide that provides continuous level measurement axially and is sensitive over its entire length. These figures apply to both the primary and backup channels.The spent fuel pool (SFP) level lower instrument span or probe bottom extends down to at least three inches below the upper limit of the range of Level 3 to account for channel accuracy or instrument loop uncertainty.
Therefore, the SFP level probe bottom/span extends down to at least elevation 70 feet 51/4 inches for Unit 2 and 70 feet 41/2 inches for Unit 3 (see Figures 1 and 2). The SFP level upper instrument span, at a minimum, includes normal water level high alarm. Note that Level 3 is shown in accordance with Nuclear Energy Institute (NEI) 12-02 Revision 1 guidance relative to the top of the rack;the top of the fuel is not shown.RAI-2 Please provide the following:
a) The design criteria that will be used to estimate the total loading on the mounting device(s), including static weight loads and dynamic loads. Describe the methodology that will be used to estimate the total loading, inclusive of design basis maximum seismic loads and the hydrodynamic loads that could result from pool sloshing or other effects that could accompany such seismic forces.b) A description of the manner in which the level sensor (and stilling well, if appropriate) will be attached to the refueling floor and/or other support structures for each planned point of attachment of the probe assembly.
Indicate in a schematic the portions of the level sensor that will serve as points of attachment for mechanical/mounting or electrical connections.
c) A description of the manner by which the mechanical connections will attach the level instrument to permanent SFP structures so as to support the level sensor assembly.RAI 2 Response: a) The loading on the probe mount and probe body includes both seismic and hydrodynamic loading using seismic response spectra that bound the IPEC design basis maximum seismic loads applicable to the installation location(s).
The static weight load is also accounted for in the modeling described below but is insignificant in comparison to seismic and hydrodynamic loads. Analytic modeling is being performed by the instrument vendor using Institute of Electrical and Electronic Engineers IEEE 344-2004 methodology.
Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 3 of 15 The simple unibody structure of the probe assembly makes it a candidate for analytic modeling and the dimensions of the probe and complex hydrodynamic loading terms in any case preclude meaningful physical testing.A detailed computational SFP hydrodynamic model has been developed for the instrument vendor by Numerical Applications, Inc., author of the GOTHIC computational fluid dynamics code. The computational model accounts for multi-dimensional fluid motion, pool sloshing, and loss of water from the pool.Seismic loading response of the probe and mount is separately modeled using finite element modeling software.
The GOTHIC-derived fluid motion profile in the pool at the installation site and resultant distributed hydrodynamic loading terms are added to the calculated seismic loading terms in the finite element model to provide a conservative estimate of the combined seismic and hydrodynamic loading terms for the probe and probe mount, specific to the chosen installation location for the probe.b) The proximal portion of the level probe is designed to be attached near its upper end (refer to vendor schematic Figure 3) to a Seismic Category I mounting bracket configured to suit the requirements of a particular SFP. The bracket may be bolted and/or welded to the SFP deck and/or SFP liner/wall according to the requirements of the particular installation per Seismic Category I requirements.
c) See RAI-2.b response above.RAI-3 Please provide the following:
a) A description of the specific method or combination of methods that you intend to apply to demonstrate the reliability of the permanently installed equipment under Beyond-Design-Basis (BDB) ambient temperature, humidity, shock, vibration, and radiation conditions.
b) A description of the testing and/or analyses that will be conducted to provide assurance that the equipment will perform reliably under the worst-case credible design basis loading at the location where the equipment will be mounted. Include a discussion of this seismic reliability demonstration as it applies to (a) the level sensor mounted in the SFP area, and (b) any control boxes, electronics, or read-out and re-transmitting devices that will be employed to convey the level information from the level sensor to the plant operators or emergency responders.
c) A description of the specific method or combination of methods that will be used to confirm the reliability of the permanently installed equipment following seismic conditions to maintain its required accuracy.RAI 3 Response: a) As stated in NEI 12-02, "Components in the area of the SFP will be designed for the temperature, humidity, and radiation levels expected during normal, event, and post-Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 4 of 15 event conditions...." Components in other areas are planned to be designed for their corresponding maximum conditions.
The discussion below describes the testing and qualification intended to demonstrate equipment reliability as needed for the expected conditions associated with the SFP level channel active components (signal processor and probe assembly including vendor-supplied hard-line coaxial cable pigtail).
Class 1 E nuclear-qualified interconnecting coaxial cable is planned to be utilized between the vendor-supplied probe coaxial cable pigtail and the signal processor
/ display.Temperature:
Signal processor:
Designed for mild environment installation.
Physical testing in an environmental chamber to demonstrate normal operation at the operating temperatures specified for the instrument.
Probe assembly:
Qualification by materials properties and use history of substantially similar probe designs in steam generator applications at significantly higher temperatures and pressures and saturated steam environments.
Humidity: Signal processor:
Designed for mild environment installation.
Physical testing in an environmental chamber to demonstrate normal operation at the operating humidity specified for the instrument.
Probe assembly:
Qualification by materials properties and use history as noted above.Shock: Signal processor:
Physical testing to commercial and/or military standards using shake-table and drop testing.Probe assembly:
Finite element analysis in conjunction with seismic modeling described above.Vibration:
Signal processor:
Physical testing to applicable commercial and/or military standards using shake-table and drop testing.Probe assembly:
The probe assembly and bracket together form a simple static unibody structure with intrinsic vibration resistance that is additionally subject to substantial damping due to the surrounding water medium. This is planned to be modeled using finite element modeling in conjunction with seismic modeling described above.Radiation:
Signal processor:
The signal processor is installed in a mild environment with radiation levels similar to background radiation, with the acknowledgement that Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 5 of 15 the radiation limit for the signal processor is similar to other commercial-grade complementary-metal-oxide-semiconductor (CMOS)-based electronics.
Radiation testing is not planned. It should be noted that the instrument performs self-diagnostics before measurements are obtained and the electronics are easily accessible for periodic replacement.
Probe assembly:
Materials properties qualification is used.b) Signal processor (electronics):
Triaxial shake-table testing is planned to be performed by the vendor to envelope seismic category 1 safe shutdown earthquake (SSE)conditions or IPEC design basis maximum seismic loads (relative to the location where the equipment is mounted) using IEEE 344-2004 methodology.
Probe assembly (level sensor): Seismic and hydrodynamic finite element analysis is performed by the vendor using relevant IEEE 344-2004 methodology (using enveloping seismic category 1 SSE conditions or IPEC design basis maximum seismic loads relative to the location where the equipment is mounted), as described in the RAI-2.a response above.c) With respect to the probe assembly, combined seismic and hydrodynamic analysis will be used to demonstrate that the probe waveguide's geometric dimensions do not change significantly as a result of the seismic conditions.
In the absence of alteration to the geometric configuration of the probe waveguide there is no mechanism for seismic excitation of the probe assembly to alter system accuracy.The accuracy of system electronics will be demonstrated following seismic excitation as part of the seismic testing protocol.RAI-4 Please provide the following:
a) A description of how the two channels of the proposed level measurement system meet this requirement so that the potential for a common cause event to adversely affect both channels is precluded.
b) Further information on how each level measurement system, consisting of level sensor electronics, cabling, and readout devices will be designed and installed to address independence through the application and selection of independent power sources, the use of physical and spatial separation, independence of signals sent to the location(s) of the readout devices, and the independence of the displays.RAI 4 Response: a) The primary instrument (Channel A) will be in the southeast corner of the SFP and the backup instrument (Channel B) will be in the northwest corner of the SFP. Locating the new instruments in the corners of the SFP takes advantage of missile and debris protection inherent in the corners. Channel A cable will be routed along the east Fuel Storage Building (FSB) wall and then along the south FSB wall to enter the Fan House, while Channel B is routed along the west FSB wall until it enters the Fan House, Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 6 of 15 maintaining physical separation in FSB. Channel A and B displays will both be located on Hydrogen Recombiner panels in each unit's Fan House. The Hydrogen Recombiner panels are designed to Seismic Category I standards.
The conceptual design provides two level instruments in the Spent Fuel Pool (SFP)within the Fuel Storage Building, with cabling routed to two electronics packages mounted on Hydrogen Recombiner panels in each unit's Fan House to provide level display. Power for each channel is provided from independent existing 120V alternating current (AC), 60 Hz power sources in the general area of the electronics packages.
As stated in the OIP, the primary channel will receive power from a different 480V bus than the backup channel. Backup power for each channel is provided by a separate battery capable of providing continuous display operation for at least three days. The battery power will be provided to the display/processor.
The design prevents failure of a single channel from causing the alternate channel to fail.b) The design provides two identical non-safety related wide-range level instruments which feed two physically and electrically independent trains of non-safety
/ seismically mounted cable and indicators to provide a highly reliable remote display of SFP water level in the Fan House. Physical separation of the two channels will be accomplished by separately routing cable and conduit as much as practical.
The use of raceways (i.e.conduit or covered trays where appropriate for existing hazards) will provide additional protection from damage due to debris during a BDB event.Independent power sources are provided such that the loss of power to one channel will not result in the loss of power to the other channel. Each channel is also provided with an independent backup power source.Each display/processor in the Fan House will have a battery installed adjacent to the display enclosure which is capable of providing power for at least three days. The separation of the display is consistent with the existing plant design basis separation criteria.RAI-5 If the level measurement channels are to be powered through a battery system (either directly or through an UPS, please provide the design criteria that will be applied to size the battery in a manner that ensures, with margin, that the channel will be available to run reliably and continuously following the onset of the BDB event for the minimum duration needed, consistent with the plant FLEX Program plans.RAI 5 Response: The sample rate estimates have been developed by the vendor using conservative instrument power requirements and measured battery capacity with draw-downs during and following exposure of the batteries to their maximum operating temperature for up to seven days. The instrument configuration is planned to be established for an automated sample rate when under battery power consistent with seven days continuous operation.
Permanent installed battery capacity for seven days continuous operation is planned consistent with NEI 12-02 duration without reliance on or crediting of potentially more rapid FLEX Program power restoration.
Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 7 of 15 Batteries are readily replaceable via spare stock without the need for recalibration to maintain accuracy of the instrument.
These measures ensure adequate power capacity and margin.RAI-6 Please provide the following:
a) An estimate of the expected instrument channel accuracy performance under both (a)normal SFP level conditions (approximately Level 1 or higher) and (b) at the BDB conditions (i.e., radiation, temperature, humidity, post-seismic and post-shock conditions) that would be present if the SFP level were at the Level 2 and Level 3 datum points.b) A description of the methodology that will be used for determining the maximum allowed deviation from the instrument channel design accuracy that will be employed under normal operating conditions as an acceptance criterion for a calibration procedure to flag to operators and to technicians that the channel requires adjustment to within the normal condition design accuracy.RAI 6 Response: a) The instrument channel level accuracy will be specified as +/- 3.0 inches for all expected conditions.
The expected instrument channel accuracy performance would be approximately
+/-1% of span (based on the sensitive range of the detector).
This is a conservative bounding instrument channel accuracy with the vendor estimating expected instrument channel accuracy is approximately one-third of the above bounding accuracy.b) In general relative to normal operating conditions, any applicable calibration procedure tolerances (or acceptance criterion) are planned to be established based on manufacturer's stated/recommended reference accuracy (or design accuracy).
The methodology used is planned to be captured in plant procedures and/or programs.RAI-7 Please provide the following:
a) A description of the capability and provisions the proposed level sensing equipment will have to enable periodic testing and calibration, including how this capability enables the equipment to be tested in-situ.b) A description how such testing and calibration will enable the conduct of regular channel checks of each independent channel against the other, and against any other permanently installed SFP level instrumentation.
c) A description of how calibration and functional checks will be performed, and the frequency at which they will be conducted.
Describe how calibration tests will be performed, and the frequency at which they will be conducted.
Provide a discussion as to how these surveillances will be incorporated into the plant surveillance program.
Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 8 of 15 d) A description of what preventative maintenance tasks are required to be performed during normal operation, and the planned maximum surveillance interval that is necessary to ensure that the channels are fully conditioned to accurately and reliably perform their functions when needed.RAI 7 Response: a) The level instrument automatically monitors the integrity of its level measurement system using in-situ capability.
Deviation of measured test parameters from manufactured or as-installed configuration beyond a configurable threshold prompts operator intervention.
Periodic calibration checks of the signal processor electronics to extrinsic National Institute of Standards and Technology (NIST)-traceable standards can be achieved through the use of standard measurement and test equipment.
The probe itself is a perforated tubular coaxial waveguide with defined geometry and is not calibrated.
It is planned to be periodically inspected electromagnetically using time-domain reflectometry (TDR) at the probe hardline cable connector to demonstrate that the probe assembly meets manufactured specification and visually to demonstrate that there has been no mechanical deformation or fouling.b) Each instrument electronically logs a record of measurement values over time in non-volatile memory that is compared to demonstrate constancy, including any changes in pool level, such as that associated with the normal evaporative loss/refilling cycle. The channel level measurements can be directly compared to each other (i.e., regular cross-channel comparisons).
The two displays are installed in close proximity to each other, thus simplifying cross channel checks. Direct measurements of SFP level may be used for diagnostic purposes if cross-channel comparisons are anomalous.
c) Performance tests (functional checks) are automated and/or semi-automated (requiring limited operator interaction) and are performed through the instrument menu software and initiated by the operator.
There are a number of other internal system tests that are performed by system software on an essentially continuous basis without user intervention but which can also be performed on an on-demand basis with diagnostic output to the display for the operator to review. Other tests such as menu button tests, level alarm, and alarm relay tests are only initiated manually by the operator.Performance checks are described in detail in the Vendor Operator's Manual, and the applicable information is planned to be contained in plant operating procedures.
Performance tests are planned to be performed periodically as recommended by the equipment vendor, for instance quarterly but no less often than the calibration interval of two years.Channel functional tests per operations procedures with limits established in consideration of vendor equipment specifications are planned to be performed at appropriate frequencies established equivalent to or more frequently than existing spent fuel pool instrumentation.
Manual calibration tests are as described above in RAI-7.a and b.
Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 9 of 15 Manual calibration and operator performance checks are planned to be performed in a periodic scheduled fashion with additional maintenance on an as-needed basis when flagged by the system's automated diagnostic testing features.Channel calibration tests per maintenance procedures with limits established in consideration of vendor equipment specifications are planned to be performed at frequencies established in consideration of vendor recommendations.
d) Periodic (e.g., quarterly or monthly) review of the system level history and log files and routine attention to any warning message on the system display is recommended by the vendor. Formal calibration checks are recommended by the vendor on a two-year interval to demonstrate calibration to external NIST-traceable standards.
Formal calibration check surveillance interval and timing would be established consistent with applicable guidance [i.e., NEI 12-02 Section 4.3; on a refueling outage interval basis and within 60 days of a planned refueling outage]. Items such as system batteries are planned to be assessed under the Preventive Maintenance (PM) program for establishment of replacement frequency.
Surveillance/PM timing/performance are planned to be controlled via tasks in the PM program.RAI-8 Please provide the following:
a) Since the "credited" primary and backup display location is other than the main control room, provide justification for prompt accessibility to displays including primary and alternate route evaluation, habitability at display location(s), continual resource availability for personnel responsible to promptly read displays, and provisions for communications with decision makers for the various SFP drain down scenarios and external events.b) The reasons justifying why the locations selected enable the information from these instruments to be considered "promptly accessible" to various drain-down scenarios and external events.c) Describe how the reliability of the "remote" display addresses the criteria in the Order and the guidance in NEI 12-02. Identify any deviations from that guidance.RAI 8 Response: a) The current design entails mounting both the primary and backup displays in the Fan House Building.
The Overall Integrated Plan will be updated to reflect this change. The following attributes apply to the display of SFP water level in the Fan House: Accessibility Information from the accessibility evaluation is scheduled to be included in the six-month update due on February 27, 2014.Habitability Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 10 of 15 Information from the habitability evaluation is scheduled to be included in the six-month update due on February 27, 2014.Resource Availability The FLEX staffing plan is currently scheduled for completion in December 2013. The information from the FLEX staffing plan is scheduled to be included in the six-month update due on February 27, 2014.Communications Portable radios will be used to transmit the SFP water level to key decision makers.b) Information from the accessibility evaluation is scheduled to be included in the six-month update due on February 27, 2014.c) The current design no longer employs the use of a remote display. The OIP will be updated to reflect this change.RAI-9 Please provide a description of the standards, guidelines and/or criteria that will be utilized to develop procedures for inspection, maintenance, repair, operation, abnormal response, and administrative controls associated with the SFP level instrumentation, as well as storage and installation of portable instruments.
RAI 9 Response: Vendor recommended inspection, maintenance, and repair procedures for the liquid level measurement system have been developed through the vendor's 30-year experience developing and manufacturing liquid level measurement and cable testing instrumentation.
These are for the most part specific to the system's proprietary electronics, subject to relevant industry standards for electronics fabrication and inspection and vendor's quality management system.Where relevant, standards for naval shipboard liquid level indicating equipment have been used to develop procedures for operation, abnormal response, and administrative controls..
Portable instrumentation is not utilized.
Both primary and backup SFPI channels incorporate permanent hard-wired installation.
The specific procedures to be used to capture the required activities described in this RAI response have not yet been developed but are planned to be developed in accordance with the vendor recommendations and Entergy processes and procedures.
0 Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 11 of 15 RAI-10 Please provide the following:
a) Further information describing the maintenance and testing program the licensee will establish and implement to ensure that regular testing and calibration is performed and verified by inspection and audit to demonstrate conformance with design and system readiness requirements.
Include a description of your plans for ensuring that necessary channel checks, functional tests, periodic calibration, and maintenance will be conducted for the level measurement system and its supporting equipment.
b) A description of how the guidance in NEI 12-02 section 4.3 regarding compensatory actions for one or both non-functioning channels will be addressed.
d) A description of what compensatory actions are planned in the event that one of the instrument channels cannot be restored to functional status within 90 days.RAI 10 Response: a) See RAI-6, 7, and 9 responses above for related descriptions of associated maintenance and testing program details. SFPI channel/equipment maintenance/preventative maintenance and testing program requirements to ensure design and system readiness are planned to be established in accordance with Entergy's processes and procedures and in consideration of vendor recommendations to ensure that appropriate regular testing, channel checks, functional tests, periodic calibration, and maintenance is performed.
Subject maintenance and testing program requirements are planned to be developed during the SFPI modification design process.b) Both primary and backup SFPI channels incorporate permanent installation (with no reliance on portable, post-event installation) of relatively simple and robust augmented quality equipment.
Permanent installation coupled with stocking of adequate spare parts reasonably diminishes the likelihood that a single channel (and greatly diminishes the likelihood that both channels) is (are) out-of-service for an extended period of time.Planned compensatory actions for unlikely extended out-of-service events are summarized as follows:#l Compensatory Action if Required Channel(s)
Required Restoration Action Restoration Action not completed Out-of- within Specified Time Restore channel to functional Immediately initiate action in status within 90 days (or if channel accordance with Note below.1 restoration not expected within 90 days, then proceed to-Compensatory Action).Initiate action within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to Immediately initiate action in 2 restore one channel to functional accordance with Note below.status, and restore one channel to Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 12 of 15# Compensatory Action if Required Channel(s)
Required Restoration Action Restoration Action not completed Out-of- within Specified Time Service functional status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.Note: Present a report to the on-site safety review committee within the following 14 days. The report shall outline the planned alternate method of monitoring, the cause of the non-functionality, and the plans and schedule for restoring the instrumentation channel(s) to functional status.c) The requested information is provided in the RAI-10.b response.
Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 13 of 15 POOL LEVELS AND REFERENCES MOUNTING BRACKET ELF VA11ON.. .L ....9'0 II--..-F- -E ---- ------ ---- ----- ---- --- -- ---. 94'-3 "... ... .. nO_. D-. L) ... .93'-B" I--------------
.L M -------------
93'-31-S 3-1 ---------------
9--------------
92"-2-----------
Y & S,. M MQtt G -------------
_$.PL1*U 1_ -.... 89'-5 W9'" 111 111111111111111 1 801-8 14"...... ...-- -- -- --1 T ---LE -- ---L- ---- ---- ---- --- 70"-5 114"-- -- -- --PV UW -- -- ----.-- --- --. 69'-8 1/4" BOTTOM OF POOL LEVEL REFERENCE 9321-F-2514-19 FSB General Arrangement Plans & Elev.2-ARP-SGF (Alarm Response Procedure)
& 9321-F-7043 9321-F-2514-19 FSB General Arrangement Plans & Elev: 9321-F-7043 (LC-650 in Section B-B)2-ARP-SGF (Alarm Response Procedure)
& 9321-F-7043 TS 3.7.11 Spent Fuel Pit Level 9321-F-2577.
FSB Aux Coolant System Sections, Section C-C NEI 12-02 (Level 3 + 10')Bottom Minr Sensitive Range, 3' below LEVEL 3 upper limit 9321-F-1388
& HOLTEC #397 to 408 9321-F-2514-19 FSB General Arrangement Plans & Elev.54.'-7 I I FIGURE 1 (Unit 2 SFP Elevation View with Levels Indicated)
Figure 1 Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 14 of 15 POOL LEVELS AND REFERENCES MOiJNTIN3 BRACKET ELEVATION MIE. ..95 ..0.-..- ------------ ....94'-2"--.. .... ----n A V ------- ----------------
------ -93'-8".... .------- --- -------- ------ ------ --- --- -93'-2"
-- ..- 91 '--8--FP-- -C T 2----PIPNG
_ -----------------
F_.LEL 89-5 31W'8 SENSOR-----------------------
..... 80'-7 112"-.-........
--TF- ---L- ---ff.L ... -, L --------------
70'-7 1/2"-------------------------
70U-4 1/2"-.-.....-
..- ..- 1PJ BV" L --_ 69'-7 1/2'0 1L LEVE11111111 I BOTTOM OF POOL LEVEL REFERENCE 9321-F-20277 RO Fuel Storage Building El. 95'-0" Plans, Sections and Details Mechanical 3-ARP-013 (Alarm Response Procedure)
& 9321-F-70433 9321-F-20277 RO Fuel Storage Building El. 95'-0" Plans, Sections and Details Mechanical 9321-F-70443 (LC-650 In Section B-B)3-ARP-013 (Alarm Response Procedure)
& 9321-F-70433 TS 3.7.14 Spent Fuel Pit Level 9321-F-25773, FSB Aux Coolant System Sections (Plan Z', Section C-C)NEI 12-02 (Level 3 + 10')Bottom MIn. Sensitive Range, 3" below LEVEL 3 upper limit IP3V-1684-0004, IP3V-1684-00032 9321-C-1 1023 RI Proposed FSB Mat. Pre-Permit Const.I I ---54'-7'FIGURE 2 (Unit 3 SFP Elevation View with Levels Indicated)
Figure 2 Attachment 1 NL-13-103 Dockets 50-247 and 50-286 Page 15 of 15 , CABLE ,,-PROBE HEAD FLANGE MOUNT Figure 3 ATTACHMENT 2 TO NL-1 3-103 LIST OF REGULATORY COMMITTMENTS ENTERGY NUCLEAR OPERATIONS, INC.INDIAN POINT NUCLEAR GENERATING UNIT NOS. 2 and 3 DOCKET NOS. 50-247 and 50-286 Attachment 2 NL-13-103 Dockets 50-247 and 50-286 Page 1 of 1 List of Regulatory Commitments The following table identifies those actions committed to by Entergy in this document.
Any other statements in this submittal are provided for information purposes and are not considered to be regulatory commitments.
TYPE (Check One) SCHEDULED COMPLETION COMMITMENT ONE- CONTINUING DATE TIME COMPLIANC (I TE ACTION E (If Required)Where requested information was not available for this RAI response in NL Six month intervals 103 it will be included in the upcoming 6-month updates, as it becomes available.