UNITED STATES 

NUCLEAR REGULATORY COMMISSION 

WASHINGTON, D.C. 20555-0001 

Vice President, Operations 

Entergy Nuclear Operations, Inc. 

Palisades Nuclear Plant 

27780 Blue Star Memorial Highway 

Covert, Ml 49043-9530 

November 26, 2013 

SUBJECT: PALISADES -INTERIM STAFF EVALUATION AND REQUEST FOR 

ADDITIONAL INFORMATION REGARDING THE OVERALL INTEGRATED 

PLAN FOR IMPLEMENTATION OF ORDER EA-12-051, RELIABLE SPENT 

FUEL POOL INSTRUMENTATION (TAC NO. MF0769) 

Dear Sir: 

On March 12,2012, the U.S. Nuclear Regulatory Commission (NRC) issued Order EA-12-051, 

"Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation" 

(Agencywide Documents Access and Management System (ADAMS) Accession 

No. ML 12054A679), to all power reactor licensees and holders of construction permits in active 

or deferred status. This order requires the licensee to have a reliable indication of the water 

level in associated spent fuel storage pools capable of supporting identification of the following 

pool water level conditions by trained personnel: (1) level that is adequate to support operation 

of the normal fuel pool cooling system, (2) level that is adequate to provide substantial radiation 

shielding for a person standing on the spent fuel pool operating deck, and (3) level where fuel 

remains covered and actions to implement make-up water addition should no longer be 

deferred. 

By letter dated February 28, 2013 (ADAMS Accession No. ML 13060A360), Entergy Nuclear 

Operations, Inc. (the licensee) provided the Overall Integrated Plan (OIP) for Palisades 

describing how it will achieve compliance with Attachment 2 of Order EA-12-051 by the spring of 

2015. By e-mail dated July 18, 2013 (ADAMS Accession No. ML 13200A328), the NRC staff 

sent a request for additional information (RAI) to the licensee. The licensee provided 

supplemental information by letters dated August 19, 2013 (ADAMS Accession 

No. ML 13231 A 126), and August 28, 2013 (ADAMS Accession No. ML 13241 A235). 

The NRC staff has reviewed these submittals with the understanding that the licensee will 

update its OIP as implementation of the Order progresses. With this in mind, the staff has 

included an interim staff evaluation with this letter to provide feedback on the OIP. The staff's 

findings in the interim staff evaluation are considered preliminary and will be revised as the OIP 

is updated. As such, none of the staff's conclusions are to be considered final. A final NRC 

staff evaluation will be issued after the licensee has provided the information requested. 

The interim staff evaluation also includes RAis, response to which the NRC staff needs to 

complete its review. The licensee should provide the information requested in the 6-month 
- 2- J 

status updates, as the information becomes available. However, the staff requests that all 

information be provided by March 31, 2015, to ensure that any issues are resolved prior to the 

date by which the licensee must complete full implementation of Order EA-12-051. The 

licensee should adjust its schedule for providing information to ensure that all this information is 

provided by the requested date. 

If you have any questions regarding this letter, please contact me at 301-415-8371 or via e-mail 

at Mahesh.Chawla@nrc.gov. 

Docket No. 50-255 

Enclosure: 

Interim Staff Evaluation and 

Request for Additional Information 

cc w/encl: Distribution via Listserv 

Sincerely, 

Mahesh Chawla, Project Manager 

Plant Licensing Branch 111-1 

Division of OperaJing Reactor Licensing 

Office of Nuclear Reactor Regulation 
INTERIM STAFF EVALUATION AND REQUEST FOR ADDITIONAL INFORMATION 

BY THE OFFICE OF NUCLEAR REACTOR REGULATION 

RELATED TO THE OVERALL INTEGRATED PLAN IN RESPONSE TO 

ORDER EA-12-051, RELIABLE SPENT FUEL POOL INSTRUMENTATION 

ENTERGY NUCLEAR OPERATIONS, INC. 

1.0 INTRODUCTION 

PALISADES NUCLEAR PLANT 

DOCKET NO. 50-255 

On March 12, 2012, the U.S. Nuclear Regulatory Commission (NRC) issued Order EA-12-051, 

"Issuance of Order to Modify Licenses with Regard to Reliable Spent Fuel Pool Instrumentation" 

(Agencywide Documents Access and Management System (ADAMS) Accession 

No. ML 12054A679), to all power reactor licensees and holders of construction permits in active 

or deferred status. This order requires, in part, that all operating reactor sites have a reliable 

means of remotely monitoring wide-range spent fuel pool (SFP) levels to support effective 

prioritization of event mitigation and recovery actions in the event of a beyond-design-basis 

(BOB) external event. The order required all holders of operating licenses issued under Title 10 

of the Code of Federal Regulations (10 CFR) Part 50, "Domestic Licensing of Production and 

Utilization Facilities," to submit to the NRC an Overall Integrated Plan (OIP) by February 28, 

2013. 

By letter dated February 28, 2013 (ADAMS Accession No. ML 13060A360), Entergy Nuclear 

Operations, Inc. (ENO) (the licensee) provided the OIP for Palisades Nuclear Plant describing 

how it will achieve compliance with Attachment 2 of Order EA-12"51 by the spring of 2015. By 

e-mail dated July 18, 2013 (ADAMS Accession No. ML 13200A328), the NRC staff sent a 

request for additional information (RAI) to the licensee. The licensee provided supplemental 

information by the letters dated August 19, 2013 (ADAMS Accession No. ML 13231 A 126), and 

August 28, 2013 (ADAMS Accession No. ML 13241 A235). 

2.0 REGULATORY EVALUATION 

Order EA-12-051 requires all holders of operating licenses issued under 10 CFR Part 50, 

notwithstanding the provisions of any Commission regulation or license to the contrary, to 

comply with the requirements described in Attachment 2 to this Order except to the extent that a 

more stringent requirement is set forth in the license. Licensees shall promptly start 

implementation of the requirements in Attachment 2 to the order and shall complete full 

implementation no later than two refueling cycles after submittal of the OIP or December 31, 

2016, whichever comes first. 

Order EA-12-051 required the licensees, by February 28, 2013, to submit to the Commission an 

OIP, including a description of how compliance with the requirements described in Attachment 2 

of the Order will be achieved. 

Enclosure 

I 
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Attachment 2 of Order EA-12-051 requires the licensees to have a reliable indication of the 

water level in associated spent fuel storage pools capable of supporting identification of the 

following pool water level conditions by trained personnel: (1) level that is adequate to support 

operation of the normal fuel pool cooling system, (2) level that is adequate to provide substantial 

radiation shielding for a person standing on the SFP operating deck, and (3) level where fuel 

remains covered and actions to implement make-up water addition should no longer be 

deferred. 

Attachment 2 of Order EA-12-051, states that the SFP level instrumentation shall include the 

following design features: 

1.1 Instruments: The instrumentation shall consist of a permanent, fixed 

primary instrument channel and a backup instrument channel. The 

backup instrument channel may be fixed or portable. Portable 

instruments shall have capabilities that enhance the ability of trained 

personnel to monitor spent fuel pool water level under conditions that 

restrict direct personnel access to the pool, such as partial structural 

damage, high radiation levels, or heat and humidity from a boiling pool. 

1.2 Arrangement: The spent fuel pool level instrument channels shall be 

arranged in a manner that provides reasonable protection of the level 

indication function against missiles that may result from damage to the 

structure over the spent fuel pool. This protection may be provided by 

locating the primary instrument channel and fixed portions of the backup 

instrument channel, if applicable, to maintain instrument channel 

separation within the spent fuel pool area, and to utilize inherent shielding 

from missiles provided by existing recesses and corners in the spent fuel 

pool structure. 

1.3 Mounting: Installed instrument channel equipment within the spent fuel 

pool shall be mounted to retain its design configuration during and 

following the maximum seismic ground motion considered in the design of 

the spent fuel pool structure. 

1.4 Qualification: The primary and backup instrument channels shall be 

reliable at temperature, humidity, and radiation levels consistent with the 

spent fuel pool water at saturation conditions for an extended period. 

This reliability shall be established through use of an augmented quality 

assurance process (e.g., a process similar to that applied to the site fire 

protection program). 

1.5 Independence: The primary instrument channel shall be independent of 

the backup instrument channel. 

1.6 Power supplies: Permanently installed instrumentation channels shall. 

each be powered by a separate power supply. Permanently installed and 

portable instrumentation channels shall provide for power connections 

from sources independent of the plant [alternating current (ac)] and [direct 
- 3-

current (de)] power di~tribution systems, such as portable generators or 

replaceable batteries. Onsite generators used as an alternate power 

source and replaceable batteries used for instrument channel power shall 

have sufficient capacity to maintain the level indication function until 

offsite resource availability is reasonably assured. 

1.7 Accuracy: The instrument channels shall maintain their designed 

accuracy following a power interruption or change in power source 

without recalibration. 

1.8 Testing: The instrument channel design shall provide for routine testing 

and calibration. 

1.9 Display: Trained personnel shall be able to monitor the spent fuel pool 

water level from the control room, alternate shutdown panel, or other 

appropriate and accessible location. The display shall provide ondemand or continuous indication of spent fuel pool water level. 

Attachment 2 of Order EA-12-051, states that the SFP instrumentation shall be maintained 

available and reliable through appropriate development and implementation of the following 

programs: 

2.1 Training: Personnel shall be trained in the use and the provision of1 

alternate power to the primary and backup instrument channels. 

2.2 Procedures: Procedures shall be established and maintained for the 

testing, calibration, and use of the primary and backup spent fuel pool 

instrument channels. 

2.3 Testing and Calibration: Processes shall be established and maintained 

for scheduling arid implementing necessary testing and calibration of the 

primary and backup spent fuel pool level instrument channels to maintain 

the instrument channels at the design accuracy. 

On A£lgust 29, 2012, the NRC issued an Interim Staff Guidance document (the ISG), 

JLD-ISG-2012-03, "Compliance with Order EA-12-051, Reliable Spent Fuel Pool 

Instrumentation" (ADAMS Accession No. ML 12221A339), to describe methods acceptable to 

the NRC staff for complying with Order EA-12-051. The I SG endorses, with exceptions and 

clarifications, the methods described in the Nuclear Energy Institute (NEI) guidance document 

NEI 12-02, Revision 1, "Industry Guidance for Compliance with NRC Order EA-12-051, to 

Modify Licenses with Regard to Reliable Spent Fuel Pool Instrumentation," dated August 2012 

(ADAMS Accession No. ML 12240A307). Specifically, the ISG states: 

The NRC staff considers that the methodologies and guidance in conformance 

with the guidelines provided in NEI 12-02, Revision 1, subject to the clarifications 

and exceptions in Attachment 1 to this ISG, are an acceptable means of meeting 

the requirements of Order EA-12-051. 
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3.0 TECHNICAL EVALUATION 

3.1 Background and Schedule 

Palisades Nuclear Plant is a single unit PWR with a single associated SFP. The SFP is 14 feet 

(ft.) 8 inches (in.) long and 38ft. 9 in. wide. 

The licensee submitted its OIP on February 28, 2013. The OIP states that installation of the 

SFP level instrumentation at Palisades Nuclear Plant will be completed prior to startup from the 

spring 2015 refueling outage. In its letter dated August 28, 2013, the licensee stated that the 

target completion date for installation of the SFP instrumentation was revised from the spring of 

2015 to the fall of 2015 to reflect a change in the 2015 refueling outage schedule. 

The NRC staff has reviewed the licensee's schedule for implementation of SFP level 

instrumentation provided in its OIP. If the licensee completes implementation in accordance 

with this schedule, it would appear to achieve compliance with Order EA-12-051 within two 

refueling cycles after submittal of the OIP and before December 31, 2016. 

3.2 Spent Fuel Pool Water Levels 

Attachment 2 of Order EA-12-051 states, in part, that 

All licensees identified in Attachment 1 to this Order shall have a reliable 

indication of the water level in associated spent fuel storage pools capable of 

supporting identification of the following pool water level conditions by trained 

personnel: (1) level that is adequate to support operation of the normal fuel pool 

cooling system [Level 1], (2) level that is adequate to provide substantial 

radiation shielding for a person standing on the SFP operating deck [Level 2], 

and (3) level where fuel remains covered and actions to implement make-up 

water addition should no longer be deferred [Level 3]. 

NEI 12-02 states, in part, that 

Level1 represents the HIGHER of the following two points: 

• The level at which reliable suction loss occurs due to uncovering of the 

coolant inlet pipe, weir or vacuum breaker (depending on the design), or 

• The level at which the water height, assuming saturated conditions, 

above the centerline of the cooling pump suction provides the required 

net positive suction head specified by the pump manufacturer or 

engineering analysis. 

In its OIP, the licensee stated, in part, that 

(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. For 

Palisades, the elevation associated with this level is 645 feet 7 inches 

(Reference 6, see G-6) due to uncovering of the skimmer opening. 
- 5-

(2) the level at which the normal fuel pool cooling pumps lose required NPSH 

assuming saturated conditions in the pool. An evaluation will be completed to 

demonstrate that this elevation is below the elevation that defines Level 1. 

The higher of the above points is (1 ). Therefore, LEVEL 1 is elevation 645 feet 

7 inches. 

In its letter dated August 19, 2013, the licensee stated, in part, that 

The water level above the pump necessary to maintain the required net positive 

suction head (NPSH) for saturated conditions is approximately 605'. This level is 

well below 645'-7", which is the level at which the cooling pump suction pipe 

begins to uncover. Therefore, the Level 1 elevation is 645'-7". 

The NRC staff notes that the elevation identified as Level 1 is adequate for normal SFP cooling 

system operation and it is also adequate to ensure the required fuel pool cooling pump Net 

Positive Suction Head (NPSH). This level represents the higher of the two points described in 

NEI 12-02 for Level 1. 

NEI 12-02 states, in part, that 

Level 2 represents the range of water level where any necessary operations in 

the vicinity of the spent fuel pool can be completed without significant dose 

consequences from direct gamma radiation from the stored spent fuel. Level 2 is 

based on either of the following: 

• 10 feet ( +1- 1 foot) above the highest point of any fuel rack seated in the 

spent fuel pools, or 

• a designated level that provides adequate radiation shielding to maintain 

personnel radiological dose levels within acceptable limits while 

performing local operations in the vicinity of the pool. This level shall be 

based on either plant-specific or appropriate generic shielding 

calculations, considering the emergency conditions that may apply at the 

time and the scope of necessary local operations, including installation of 

portable SFP instrument channel components. 

In its OIP, the licensee stated, in part, that 

(1) 10 feet± 1 foot above the highest point of any fuel rack seated in the spent 

fuel pool. The elevation associated with this level is 634 feet 5 inches ± 1 foot 

(i.e., Level 3 + 10 feet). 

· (2) A designated level that provides adequate radiation shielding to maintain 

personnel dose within acceptable limits while performing local operations in the 

vicinity of the pool. This level is based on plant-specific or appropriate generic 

shielding calculations. The elevation associated with this lev~l is not calculated 

since item {1) is used to establish Level 2 as permitted by NEI 12-02 Revision 1. 
- 6 -

Therefore, LEVEL 2 is elevation 634 feet 5 inches (1 0 feet above Level 3) .... 

In its letter dated August 19, 2013, the licensee provided a sketch depicting the elevations 

identified as Levels 1, 2 and 3 and the SFP level instrumentation sensor range. The NRC staff 

reviewed this sketch and notes that Level 2 is identified at an elevation of 634ft. 5 in., which is 

more than 10 ft. above the top of the fuel racks. 

In its OIP, the licensee stated that other hardware stored in the SFP will be evaluated to ensure 

that it does not adversely interact with the SFP instrument probes during a seismic event. In 

NRC email dated July 18, 2013, the staff requested information regarding the dose impact from 

other irradiated material stored in the SFP in the identification of the elevation for Level 2. 

In its letter dated August 19, 2013, the licensee stated that the response to this question is 

currently scheduled to be included in the second six-month report to the staff, due on 

February 28, 2014. The staff has identified this request as: 

RAI #1 

Given the potential for varied dose rates from other materials stored in the SFP, please 

describe how level 2 will be adjusted to other than the elevation provided in section 2 

above. 

(This information was previously requested as RAI-l. C. in NRC email dated July 18, 2013) 

NEI 12-02 states, in part, that 

Level 3 corresponds nominally (i.e., +1- 1 foot) to the highest point of any fuel 

rack seated in the spent fuel pool. Level 3 is defined in this manner to provide 

the maximum range of information to operators, decision makers and emergency 

response personnel. 

In its OIP, the licensee stated that Level 3 is at elevation 624ft. 5 in., which is the highest point 

of any fuel rack seated in the spent fuel pool. 

In its letter dated August 19, 2013, the licensee provided a sketch depicting the elevations 

identified as Levels 1, 2 and 3 and the SFP level instrumentation sensor range. The NRC staff 

reviewed this sketch and notes that Level 3 is identified at an elevation of 625 ft. 5 in. which is 

1 foot above the highest point of any spent fuel storage rack seated in the SFP. With an 

uncertainty in level sensor reading of approximately ± 3 inches, an indicated reading at that 

value should demonstrate that there will be approximately 9 inches of water remaining above 

the top of the highest point of any fuel rack. 

The licensee's proposed plan, with respect to identification of Levels 1 and 3, appears to be 

consistent with NEI 12-02, as endorsed by the ISG. 
- 7 -

3.3 Design Features: Instruments 

Attachment 2 of Order EA-12-051, states, in part, that 

The instrumentation shall consist of a permanent, fixed primary instrument 

channel and a backup instrument channel. The backup instrument channel may 

be fixed or portable. Portable instruments shall have capabilities that enhance 

the ability of trained personnel to monitor spent fuel pool water level under 

conditions that restrict direct personnel access to the pool, such as partial 

structural damage, high radiation levels, or heat and humidity from a boiling pool. 

NEI 12-02 states, in part, that 

A spent fuel pool level instrument channel is considered reliable when the 

instrument channel satisfies the design elements listed in Section 3 

[Instrumentation Design Features] of this guidance and the plant operator has 

fully implemented the programmatic features listed in Section 4 [Program 

Features]. 

In its OIP, the licensee stated that both the primary and backup instrument level channels would 

be permanent, mounted directly within the SFP and that each instrument channel would be 

capable of monitoring SFP water'level over a single continuous span from above Level 1 to 

within 1 foot of the top of the spent fuel racks. 

In its letter dated August 19, 2013, the licensee stated, in part, that 

' 

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 625'-2" (see 

Figure 1 ). The SFP level upper instrument span, at a minimum, includes the high 

level alarm. Note that Level 3 is shown in accordance with Nuclear Energy. 

Institute (NEI) 12- 02, "Industry Guidance for Compliance with NRC Order 

EA-12-051, To Modify Licenses with Regard to Reliable Spent Fuel Pool 

Instrumentation," Revision 1, guidance relative to the top of the rack; the top of 

the fuel is not shown. 

In its letter dated August 19, 2013, the licensee provided a sketch depicting the elevations 

identified as Levels 1, 2 and 3 and the SFP level instrumentation measurement range. The 

NRC staff reviewed this sketch and notes that, consistent with the information provided, the 

measurement range goes from the 647ft. 10 in. to 625ft. 2 in. 

The NRC staff notes that the range specified for the licensee's instrumentation will cover 

Levels 1, 2, and 3 as described in Section 3.2 above. The licensee's proposed plan, with 

respect to the number of channels and the range of the SFP level instrumentation appears to be 

consistent with NEI 12-02, as endorsed by the ISG. 
- 8-

3.4 Design Features: Arrangement 

Attachment 2 of Order EA-12-051 , states, in part, that 

The spent fuel pool level instrument channels shall be arranged in a manner that 

provides reasonable protection of the level indication function against missiles 

that may result from damage to the structure over the spent fuel pool. This 

protection may be provided by locating the primary instrument channel and the 

fixed portions of the backup instrument channel, if applicable, to maintain 

instrument channel separation within the spent fuel pool area, and to utilize 

inherent shielding from missiles provided by existing recesses and corners in the 

spent fuel pool structure. 

NEI 12-02 states, in part, that 

The intent of the arrangement requirement is to specify reasonable separation 

and missile protection requirements for permanently installed instrumentation 

used to meet this order. Although additional missile barriers are not required to 

be installed, separation and shielding cari help minimize the probability that 

damage due to an explosion or extreme natural phenomena (e.g., falling or winddriven missiles) will render fixed channels of SFP instrumentation unavailable. 

Installation of the SFP instrument channels shall be consistent with the plantspecific SFP design requirements and should not impair normal SFP function. 

Channel separation should be maintained by locating the installed sensors in 

different places in the SFP area. · 

In its OIP, the licensee stated, in part that 

Level instruments will be installed in the approximate locations shown on 

Attachment 1. Separation of the channels/probes reduces the potential for falling 

debris or missiles affecting both channels of instrumentation. This placement 

coupled with separate routing paths for cables and use of rigid conduit provides 

reasonable protection against falling debris and structural damage. 

In the SFP area, cables shall be routed in seismically mounted rigid metal 

conduit. Outside the pool area, cables shall be routed in seismically mounted 

rigid metal conduit, trays, or raceways ... 

In its OIP, the licensee provided a sketch showing the SFP instrument locations and 

approximate cable routing .. In its letter dated August 19, 2013, the licensee provided an 

additional sketch depicting the inside dimensions of the SFP as well as the planned placement 

of the primary and backup level sensors in the SFP. The NRC staff reviewed these sketches 

and notes that the SFP level instrument probes are located on the north and south walls of the 

SFP and that from that point the cables are routed separately to the display locations . 

.The licensee's proposed arrangement for the primary and backup SFP level instrumentation 

appears to be consistent with NEI 12-02, as endorsed by the ISG. 
- 9 -

3,5 Design Features: Mounting 

Attachment 2 of Order EA-12-051 states, in part, that 

Installed instrument channel equipment within the spent fuel pool shall be 

mounted to retain its design configuration during and following the maximum 

seismic ground motion considered in the design of the spent fuel pool structure. 

NEI 12-02 states, in part, that 

The mounting shall be designed to be consistent with the highest seismic or 

safety classification of the SFP. An evaluation of other hardware stored in the 

SFP shall be conducted to ensure it will not create adverse interaction with the 

fixed instrument location(s). 

The basis for the seismic design for mountings in the SFP shall be the plant 

seismic design basis at the time of submittal of the Integrated Plan for 

implementing NRC Order EA-12-051. · 

In its OIP, the licensee stated that both the primary and backup system will be installed as 

seismic category I to meet the NRC JLD-ISG-2012-03 and NEI 12-02 guidance requirements. 

The licensee also stated that other hardware stored in the SFP will be evaluated to ensure that 

it does not adversely interact with the SFP instrument probes during a seismic event. 

In its August 19, 2013, letter, the licensee stated, in part, .that 

The .loading on the probe mount and probe body includes ~oth seismic and 

hydrodynamic loading using seismic response spectra that bound the PNP 

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, "IEEE Recommended Practice for 

Seismic Qualification of Class 1 E Equipment for Nuclear Power Generating 

Stations," methodology. 

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 
- 10-

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. 

The proximal portion of the level probe is designed to be attached near its upper 

end (refer to Figure 3) to a Seismic Category I mounting bracket configured to 

suit the requirements of a particular SEP. 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. 

The NRC staff notes that the proposed application of such seismic design criteria appears to be 

reasonable and addresses the staff-endorsed NEI 12-02 guidance stating that the channel is to 

be designed consistent with the highest seismic or safety classification of the SFP. The 

licensee's proposed plan, with respect to the seismic design of the mounting, appears to be 

consistent with NEI 12-02, as endorsed by the ISG. The staff plans to verify the results of the 

licensee's seismic testing and analysis report when it is completed based on the licensee's 

response to the following RAis. 

RAI#2 

Please provide the analyses verifying the seismic capability of the level probes, the 

mounting brackets, and the electronics units, and provide the results of the analysis of 

the combined ·maximum seismic and hydrodynamic forces on the cant.ilevered portion of 

the assembly exposed to the potential sloshing effects. Show that the SFP instrument 

design configuration will be maintained during and following the maximum seismic 

ground motion considered in the design of the SFP structure. 

RAI#3 

For each of the mounting attachments required to attach SFP Level equipment to plant 

structures, please describe the design inputs, and the methodology that will be used to 

qualify the structural integrity of the affected structures/equipment. 

While a<;Jdressing the potential for adverse interactions of the SFP level instruments with other 

hardware stored in the SFP the licensee stated within its letter dated August 19, 2013, in part, 

that 

An evaluation of non-special nudear material inventory located in the SFP will be 

performed during the spent fuel pool instrumentation (SFPI) modification 

process. Non-special nuclear material access to the SFP is governed by · 

EN-RE-220, "PWR Control of Miscellaneous Material in the Spent Fuel Pool." 

This procedure will be used to prevent any instrument interference from 

non-special nuclear materials. 

The NRC staff notes that an evaluation to address the potential for interaction between 

non-nuclear material inventory located in the SFP and the SFP level instruments will be 

performed during the SFP instrumentation modification process. The staff has identified this 

request as: 
- 11 -

RAI#4 

Please address how other hardware stored in the SFP will not create adverse interaction 

with the fixed instrument location(s). 

(This information was previously requested as RAI-3.d in NRC letter dated July 18, 2013) 

" 

3.6 Design Features: Qualification 

Attachment 2 of Order EA-12-051 states, in part, that 

The primary and backup instrument channels shall be reliable at temperature, 

humidity, and radiation levels consistent with the spent fuel pool water at 

saturation conditions for an extended period. This reliability shall be established 

through use of an augmented quality assurance process (e.g. a process similar 

to that applied to the site fire protection program). 

N El 12-02 states, in part, that 

The instrument channel reliability shall be demonstrated via an appropriate 

combination of design, analyses, operating experience, and/or testing of channel 

components for the following sets of parameters, as described in the paragraphs 

below: 

• conditions in the area of instrument channel component use for all 

instrument components, 

• effects of shock and vibration on instrument channel· components used 

during any applicable event for only installed components, and 

• seismic effects on instrument channel components used during and 

following a potential seismic event fo·r only installed components ... 

The NRC staff assessment of the instrument qualification is discussed in the following 

subsections below: (3.6.1) Augmented Quality Process, (3.6.2) Post Event Conditions, (3.6.3) 

Shock and Vibration, and (3.6.4) Seismic Reliability. 

3. 6. 1 Augmented Quality Process 

Appendix A-1 of the guidance in NEI 12-02 describes a quality assurance process for nonsafety systems and equipment that is not already covered by existing quality assurance 

requirements. Within the ISG, the NRC staff found the use of this quality assurance process to 

be an acceptable means of meeting the augmented quality requirements of Order EA-12-051. 

In its OIP, the licensee stated, in part, that 

Augmented quality requirements will be applied to all components in the 

instrumentation channels for: 
- 12-

• design control 

• procurement document control 

• instructions, procedures, and drawings 

• control of purchased material, equipment, and services 

• inspection, testing, and test control 

• inspections, test, and operating status 

• nonconforming items 

• corrective actions 

• · records 

• audits 

The licensee's proposed augmented quality assurance process appears to be consistent with 

NEI 12-02, as endorsed by the ISG. 

3.6.2 Post Event Conditions 

N El 12-02 states, in part, that 

The temperature, humidity and radiation levels consistent with conditions in the 

vicinity of the [SFP] and the area of use considering normal operational, event 

and post-event conditions for no fewer than seven days post-event or until offsite resources can be deployed by the mitigating strategies resulting from Order 

EA-12-049 should be considered. Examples of post-event (beyond-designbasis) conditions to be considered are: 

• radiological conditions for a normal refueling quantity of freshly 

discharged (1 00 hours) fuel with the SFP water level 3 as described in 

this order, 

• temperatures of 212 degrees F and 100% relative humidity environment, 

• boiling water and/or steam environment 

• a concentrated borated water environment, and ... 

In its OIP, the licensee stated, consistent with NEI 12-02, in part, that 

Components in the area of the SFP will be designed for the temperature, 

humidity, and radiation levels expected during normal, event, and post-event 

conditions for no fewer than seven days post-event or until off-site resources can 

be deployed by the mitigating strategies resulting from Order EA-12-049, Order 

Modifying Licenses With Regard to Requirements for Mitigation for 

Beyond-Design-Basis External Events. Examples of post event conditions that 

will be considered are: 

• Radiological conditions for a normal refueling quantity of freshly discharged 

(100 hours) fuel with SFP water level with in 1 foot of the top of the SFP racks 

(Level 3), 
- 13-

• Temperature of 212 degrees F and 100% relative humidity environment, 

• Boiling water and steam environment 

• Concentrated borated water environment, and ... 

Related to radiological conditions, in its OIP the licensee stated, in part, that 

Equipment located in the SFP will be qualified to withstand a total accumulated 

dose of expected lifetime at normal conditions plus accident dose received at 

post event conditions with SFP water level within 1 foot of the top of the fuel rack 

seated in the spent fuel pool (Level 3). 

The metal probe and cable in the spent fuel pool area are robust components 

that are not adversely affected by expected radiation, temperature, or humidity. 

The areas selected for display/processor installation are considered mild 

environments, such that personnel access is not prohibited by radiation, 

temperature, or humidity, and are readily accessible by operators during or after 

a BDBE event. 

In its letter dated August 19, 2013, the licensee stated, in part, that 

RAI#S 

Radiation: 

Signal processor: The signal processor is installed in a mild environment with 

radiation levels similar to background radiation, with the acknowledgement that 

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. 

Please provide analysis of the maximum expected radiological conditions (dose rate and 

total integrated dose) to which the sensor electronics will be exposed. Also, please 

provide documentation indicating the radiological dosage the electronics for this 

equipment are capable of withstanding. Please discuss the time period over which the 

analyzed total integrated dose is evaluated to be applied. 
- 14-

While addressing post-event temperature and humidity conditions, in its letter dated August 19, 

2013, the licensee stated, in part, that 

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. ' 

The NRC staff notes that information related to the qualification and test program to confirm the 

reliability of the permanently installed equipment during and following BOB events are not 

available for review. The staff has identified these requests as: · 

RAI#6 

Please provide information indicating the maximum expected ambient temperature in the 

room in which the sensor electronics will be located under BOB conditions with no ac 

power available to run Heating Ventilation and Air Conditioning (HVAC) systems, and 

whether the sensor electronics are capable of continuously performing required 

functions under this expected temperature condition .. 

RAI#7 

Please provide information indicating the maximum expected relative humidity in the 

room in which the sensor electronics will be located under BOB conditions, with no ac 

power available to run HVAC systems, and whether the sensor electronics are capable of 

continuously performing required functions under this expected humidity condition. 

3.6.3 Shock and Vibration 

NEI 12-02 states, in part, that 

Applicable components of the instrument channels are rated by the manufacturer 

(or otherwise tested) for shock and vibration at levels commensurate with those 

of postulated design basis event conditions in the area of instrument channel 

component use using one or more of the following methods: 
- 15 -

• instrument channel components use known operating principles, are 

supplied by manufacturers with commercial quality programs (such as 

IS09001) with shock and vibration requirements included in the purchase 

specification and/or instrument design, ano commercial design and 

testing for operation in environments where significant shock and 

vibration loadings are common, such as for portable hand-held devices or 

transportation applications; 

• substantial history of operational reliability in environments with significant 

shock and vibration loading, such as transportation applications, or 

• use of component inherently resistant to shock and vibration loadings or 

are seismically reliable such as cables. 

In its OIP, the licensee stated that components of the instrument channels would be qualified for 

shock and vibration using the methods identified in NEI 12-02. 

In its letter dated August 19, 2013, the licensee stated, in part, that 

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 iri conjunction with seismic modeling 

described above. 

The NRC staff has concerns with the licensee's lack of information regarding qualification of the 

SFP level instruments for shock and vibration. The staff has identified these requests as: 

RAJ #8 

Please provide a description of the specific method or combination of methods that will 

be used to demonstrate the reliability of the permanently installed equipment under BOB 

shock and vibration conditions. Identify the specific commercial and/or. military 

standards that will be used to establish the testing requirements, and the specific 

acceleration levels and frequencies that will be simulated. 
- 16 -

RAI #9 

For RAI #8 above, please provide the results for the selected methods, tests and 

analyses used to demonstrate the qualification and reliability of the installed equipment 

in accordance with the Order requirements. 

3.6.4 Seismic Reliability 

The ISG recommends the use of Sections 7, 8, 9, and 10 of IEEE 344-2004 for seismic 

qualification of the SFP level instrumentation. 

In its OIP, the licensee stated, in part, that 

For seismic effects on instrument channel components used after a potential 

seismic event for only installed components (with the exception of replaceable 

batteries and chargers), the following measures will be used to verify that the 

design and installation is adequate: 

• Components will be rated by the manufacturer (or otherwise tested) for 

seismic effects at levels commensurate with those of postulated design 

basis event conditions in the area of instrument channel component. .. 

• Augmented quality requirements will be applied to all components in the 

instrument channels ... 

In its letter dated August 19, 2013, the licensee stated, in part, that 

Signal processor (electronics): Triaxial shake-table testing is planned to be 

performed by the vendor to envelope Seismic Category I safe shutdown 

earthquake (SSE) conditions or PNP 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 I SSE conditions or PNP design basis 

m.aximum seismic loads relative to the location where the equipment is 

mounted), as described in the RAI-4.a response above. 

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. 
- 17-

The NRC staff notes the licensee will demonstrate the reliability of the seismic design and 

installation in accordance with NEI 12-02, as endorsed by the ISG. The licensee's planned 

approach with respect to the seismic reliability of the instrumentation appears to be consistent 

NEI 12-02, as endorsed by the ISG. However, the staff plans to verify the results of the 

licensee's seismic testing and analysis when it is completed. The staff has identified this 

request as: 

RAI #10 

Please provide an evaluation of the vendor analysis and seismic testing results and 

show that the instrument performance reliability, following exposure to simulated 

seismic conditions representative of the environment anticipated for the SFP structures 

at Palisades, has been adequately demonstrated. 

3.6.5 Qualification Evaluation Summary 

Upon acceptable resolution of the RAis in Section 3.6, the NRC staff will be able to make a 

conclusion regarding the instrument qualification. 

3.7 Design Features: Independence 

Attachment 2 of Order EA-12-051 states, in part, that 

The primary instrument channel shall be independent of the backup instrument 

channel. 

NEI 12-02 states, in part, that 

Independence of permanently installed instrumentation, and primary and backup 

channels, is obtained by physical and power separation commensurate with the 

hazard and electrical isolation needs. If plant AC or DC power sources are used 

then the power sources shall be from different buses and preferably different 

divisions/channels depending on available sources of power. 

In its OIP, the licensee stated that the primary instrument channel would be independent of the 

backup instrument channel. The licensee stated that independence would be obtained by 

physical separation of components between channels and the use of normal power supplied 

from separate 480V buses. 

In its letter dated August 19, 2013, the licensee stated, in part, that 

The primary instrument (Channel A) will be along the north wall at the west end 

of the SFP and the backup instrument (Channel B) will be along the south wall at 

the east end. Locating the new instruments across the pool from each other 

takes advantage of the distance between the probes for missile and debris 

protection. 

The conceptual design provides two level instruments in the SFP with cabling 

routed to two display/processors, one of which will be mounted in existing panels 
- 18-

in the Control Room, with the other mounted in the Radwaste Control Panel 

Room Cabinet C1 04 at the 590' elevation. Power for each channel is provided 

from independent 120VAC, 60 Hz power sources. Backup power is provided by 

a battery capable of providing continuous display operation for at least three 

days. The battery will be provided with the display/processor. The design 

prevents failure of a single channel from causing the alternate channel to fail. 

The design provides two identical non-safety related wide-range level 

instruments which feed two independent channels of non-safety cable and 

indicators to provide a highly reliable remote display of SFP water level. 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 dam~ge due to debris during a BOB event. 

The NRC staff notes that the licensee's proposed independence and physical and power 

separation appears to be consistent with NEI 12-02, as endorsed by the ISG. This proposed 

arrangement would not affect the operation of the independent channel under BOB event 

conditions, and the electrical functional performance of each level measurement channel would 

be considered independent of the other channel. However, the NRC staff plans to review the 

final electrical power supply design information to complete its review. The NRC staff has 

identified this request as: 

RAI #11 

Please provide the NRC staff with the final configuration of the power supply source for 

each channel so the staff may conclude the two channels are independent from a power 

supply assignment perspective. 

3.8 Design Features: Power Supplies 

Attachment 2 of Order EA-12-051 , states in part, that 

Permanently installed instrumentation channels shall each be powered by a 

separate power supply. Permanently installed and portable instrumentation 

channels shall provide for power connections from sources independent of the 

plant ac and de power distribution systems, such as portable generators or 

replaceable batteries. Onsite generators used as an alternate power source and 

replaceable batteries used for instrument channel power shall have sufficient 

capacity to maintain the level indication function until offsite resource availability 

is reasonably assured. 

NEI 12-02 states, in part, that 

The normal electrical power supply for each channel shall be provided by 

different sources such that the loss of one of the channels primary power supply 

will not result in a loss of power supply function to both channels of SFP level 

instrumentation. 
- 19-

All channels of SFP level instrumentation shall provide the capability of 

connecting the channel to a source of power (e.g., portable generators or 

replaceable batteries) independent of the normal plant AC and DC power 

systems. For fixed channels this alternate capability shall include the ability to 

isolate the installed channel from its normal power supply or supplies. The 

portable power sources for the portable and installed channels shall be stored at 

separate locations, consistent with the reasonable protection requirements 

associated with NEI 12-06 (Order EA-12-049). The portable generator or 

replaceable batteries should be accessible and have sufficient capacity to 

support reliable instrument channel operation until off-site resources can be 

deployed by the mitigating strategies resulting from Order EA-12-049. 

If adequate power supply for either an installed or portable level instrument 

credits intermittent operation, then the provisions shall be made for quickly and 

reliably taking the channel out of service and restoring it to service. For example, 

a switch on the power supply to the channel is adequate provided the power can 

be periodically interrupted without significantly affecting the accuracy and 

reliability of the instrument reading. Continuous indication of SFP level is 

acceptable only if the power for such indication is demonstrably adequate for the 

time duration specified in section 3.1 [.] 

In its OIP, the licensee stated, in part, that 

The power supplies for the instrument channels are shown on Attachment 2 and 

arranged as follows: 

• Each instrument channel is normally powered from 120VAC 60Hz plant 

power to support continuous monitoring of SFP level. The primary channel 

receives power from a different 480V bus than the backup channel. 

Therefore, loss of any one 480V bus does not result in loss of normal 

120VAC power for both instrument channels. 

• On loss of normal 120VAC power, each channel's UPS automatically 

transfers to a dedicated backup battery. If normal power is restored, the 

channel will automatically transfers back to the normal AC power. 

• The backup batteries are maintained in a charged state by commercial-grade 

uninterruptible power supplies. The batteries are sized to be capable of 

supporting intermittent monitoring for a minimum of 3 days of operation. This 

provides adequate time to allow the batteries to be replaced or until off-site 

resources can be deployed by the mitigating strategies resulting from 

Order EA-12-049 Revision 0. 

• An external connection permits powering the system from any portable DC 

source. 

• Instrument accuracy and performance are not affected by restoration of 

power or restarting the processor. 
-20-

Additionally, in its OIP, the licensee stated that instrument power is derived from the 

display/processors, and that the backup batteries and associated UPS are located at the 

processor, seismically mounted, and qualified for the expected environment. 

In its August 19, 2013 letter, the licensee stated, in part, that 

Each display/processor will have a battery installed adjacent to the display 

enclosure which is capable of providing power for at least three days ... 

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 potentia.lly more rapid FLEX 

Program power restoration. 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. 

The NRC staff notes the proposed power supply design and criteria for sizing of the battery 

appear to be consistent with NEI 12-02, as endorsed by the ISG. However, the staff plans to 

verify the final configuration of the electrical design and the results of the licensee's calculation 

for required duty cycle given the final design load of the instrument channel for its installed 

configuration. The staff has identified this request as: 

RAI #12 

Please provide the results of the calculation depicting the battery backup duty cycle 

requirements demonstrating battery capacity is sufficient to maintain the level indication 

function until offsite resource availability is reasonably assured. 

3.9 Design Features: Accuracy 

Attachment 2 of Order EA-12-051 states, in part, that 

The instrument channels shall maintain their designed accuracy following a 

power interruption or change in power source without recalibration. 

NEI 12-02 states, in part, that 

Accuracy should consider operations while under SFP BOB conditions, e.g., 

saturated water, steam environment, or concentrated borated water. 

Additionally, instrument accuracy should be sufficient to allow trained personnel 

to determine when the actual level exceeds the specified lower level of each 

indicating range (levels 1, 2 and 3) without conflicting or ambiguous indication. 
- 21 -

In its OIP, the licensee stated, in part, that 

Accuracy and indication features are as follows: 

• Accuracy: The absolute system accuracy is better than± 3 inches. This 

accuracy is applicable for normal conditions and the temperature, humidity, 

chemistry, and radiation levels expected for BDBE event conditions. 

• Trending: The display trends and retains data when powered from either 

normal or backup power. 

• Restoration after Loss of Power: The system automatically swaps to 

available power (backup battery power or external DC source) when normal 

power is lost. Neither the source of power nor system restoration impact 

accuracy. Previously collected data is retained. 

• Diagnostics: The system performs and displays the results of real-time 

information related to the integrity of the cable, probe, and instrument 

channel. 

The above features ensure that trained personnel can easily determine when 

SFP level falls below each regulatory level (levels 1, 2, and 3) without conflicting 

or ambiguous indication. 

In its letter dated August 19, 2013, the licensee stated, in part, that 

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). 

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. 

The NRC staff notes the estimated instrument channel design accuracies and methodology 

appear to be sufficient to maintain the instrument channels to within their designed accuracies 

before significant drift can occur. The NRC staff plans to verify that the licensee's proposed 

instrument performance is consistent with these estimated accuracy values. Further, the NRC 

staff plans to verify that the channels will retain these accuracy performance values following a 

loss of power and subsequent restoration of power. The staff has identified these requests as: 

RAI #13 

Please ,provide an analysis verifying the proposed instrument performance is consistent 

with these estimated accuracy normal and BOB values. Please demonstrate the 
-22-

channels will retain these accuracy performance values following a Joss of power and 

subsequent restoration of power. 

RAJ #14 

Please provide a description of the methodology that will be used for determining the 

maximum allowed deviation from the. instrument channel design accuracy to be 

employed under normal operating conditions as an acceptance criterion for a calibration 

procedure to alert operators and technicians of the need for adjustment to within normal 

design accuracy. 

(This information was previously requested as RAI-7.b in NRC email dated July 18, 2013) 

3.10 Design Features: Testing 

Attachment 2 of Order EA-12-051 states, in part, that 

The instrument channel design shall provide for routine testing and calibration. 

NEI 12-02 states, in part, that 

Static or non-active installed (fixed) sensors can be used and should be designed 

such that testing and/or calibration can be performed in-situ. For microprocessor 

based channels the instrument channel design shall be capable of testing while 

mounted in the pool. 

In its OIP, the licensee stated that the display/processor performs automatic in-situ calibration 

and automatically monitors for cable, connector, and probe faults using time domain 

reflectometry (TOR) technology. The licensee also stated that channel degradation due to age 

or corrosion is not expected but can be identified by monitoring trends. · · 

In its letter dated August 19, 2013, the licensee stated, in part, tha:t 

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 (TOR) 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. 
-23-

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). Direct measurements of SFP level may be used for 

diagnostic purposes if cross-channel comparisons are anomalous. 

The NRC staff notes the results of the comparison between the SFP level instrument channels 

can be compared to acceptance criteria described in Section 3.9 above to determine if 

recalibration or troubleshooting is needed. However, the NRC staff has concerns with the lack 

of information regarding the feasibility of the licensee's process for in-situ calibration to ensure 

that the design accuracy will be maintained. The staff has identified this request as: 

RAI #15 

Please provide a description of the in-situ calibration process at the SFP location that 

wiil result in th~ channel calibration being maintained at its design accuracy. 

3.11 Design Features: Display 

Attachment 2 of Order EA-12-051 states, in part, that 

Trained personnel shall be able to monitor the spent fuel pool water level from 

the control room, alternate shutdown panel, or other appropriate and accessible 

location. The display shall provide on-demand or continuous indication of spent 

fuel pool water level. 

NEI 12-02 states, in part, that 

The intent of this guidance is to ensure that information on SFP level is 

reasonably available to the plant staff and decision makers. Ideally there will be 

an indication from at least one channel of instrumentation in the control room. 

While it is generally recognized (as demonstrated by the events at Fukushima 

Daiichi) that SFP level will not change rapidly during a loss of spent fuel pool 

cooling scenario, more rapid SFP drain down cannot be entirely discounted. 

Therefore, the fact that plant personnel are able to determine the SFP level will 

satisfy this requirement, provided the personnel are available and trained in the 

use of the SFP level instrumentation (see Section 4.1) and that they can 

accomplish the task when required without unreasonable delay. 

SFP level indication from the installed channel shall be displayed in the control 

room, at the alternate shutdown panel, or another appropriate and accessible 

location (reference NEI 12-06). An appropriate and accessible location shall 

have the following characteristics: 

• occupied or promptly accessible to the appropriate plant staff giving 

appropriate consideration to various drain down scenarios, 
-24-

• outside of the area surrounding the SFP floor, e.g., an appropriate 

distance from the radiological sources resulting from an event impacting 

the SFP, 

• inside a structure providing protection against adverse weather, and 

• outside of any very high radiation areas or LOCKED HIGH RAD AREA 

during normal operation. 

If multiple display locations beyond the required "appropriate and accessible 

location" are desired, then the instrument channel shall be designed 'with the 

capability to drive the multiple display locations without impacting the primary 

"appropriate and accessible" display. 

In its OIP, the licensee stated that the primary (Channel A) and backup (Channel B) instrument 

displays would be located in the Main Control Room and the Auxiliary Building, respectively. 

In its letter dated August 19, 2013, the licensee stated, in part, that 

The backup display will be mounted in the Radwaste Control Panel Room Cabinet C1 04 

at the 590' elevation of the Auxiliary Building. This cabinet is located in Passage 121, 

and can be accessed via Stairwell No. 16 and Door 75, or via Corridor 1 06A through 

Door 190. Both Stairwell 16 and Corridor 1 06A can be approached from the north, east, 

and west via Corridor 1 06. 

A habitability evaluation is in progress. The updated information is currently scheduled 

to be included in the second SFP six-month status report due February 28, 2014. 

The FLEX staffing plan is currently scheduled to be completed by December 2013. The 

information is scheduled to be included in the FLEX six-month status report for 

February 28, 2014. 

If necessary, portable radios will be used to communicate with decision makers. 

The permanently mounted back-up channel display can be considered promptly 

accessible, because it can be reached within the 30 minute deployment requirement that 

exists for portable instrumentation (Section 3.1 of NEI 12-02). 

The NRC staff notes the NEI guidance for "Display" specifically mentions the control room as an 

acceptable location for SFP instrumentation displays as it is occupied or promptly accessible, 

outside the area surrounding the SFP, inside a structure providing protection against adverse 

weather and outside of any very high radiation areas or LOCKED HIGH RAD AREA during 

normal operation. The licensee's proposed location for the primary SFP instrumentation display 

appears to be consistent with NEI 12-02, as endorsed by the ISG. 

Regarding the backup display, the NRC staff notes the intended location of the secondary SFP 

instrumentation display is the radwaste control panel room. The NRC staff has concerns with 

the licensee's lack of information regarding the accessibility, habitability, availability of personnel 
-25-

and communications as it relates to the location of the SFP level instrumentation backup 

display. The staff has identified this request as: 

RAI #16 

For the SFP level instrumentation backup display located in the radwaste control panel 

room, please describe the evaluation used to validate the display location can be 

accessed without unreasonable delay following a BOB event. Include the time available 

for personnel to access the display as credited in the evaluation, as well as the actual 

time (e.g., based on walk-throughs) that it will take for personnel to access the backup 

display. Additionally, please include a description of the radiological and environmental 

conditions on the paths personnel might take. Describe whether the display location 

remains habitable for radiological, heat and humidity, and other environmental 

conditions following a BOB event. Describe whether personnel are continuously 

stationed at the backup display or monitor the display periodically. 

3.12 Programmatic Controls: Training 

Attachment 2 of Order EA-12-051 states, in part, that 

Personnel shall be trained in the use and the provision of alternate power to the 

primary and backup instrument channels. 

NEI 12-02 states, in part, that 

The personnel performing functions associated with these SFP level 

instrumentation channels shall be trained to perform the job specific functions 

necessary for their assigned tasks (maintenance, calibration, surveillance, etc.). 

SFP instrumentation should be installed via the normal modification processes. 

In some cases, utilities may choose to utilize portable instrumentation as a 

portion of their SFP instrumentation response. In either case utilities should use 

the Systematic Approach to Training (SAT) to identify the population to be 

trained; The SAT process should also determine both the initial and continuing 

elements of the required training. 

In its OIP, the licensee stated, in part, that 

The Systematic Approach to Training (SAT) will be used to identify the population 

to be trained and to determine both the initial and continuing elements of the 

required training. Training will be completed prior to placing the instrumentation 

in service. 

The licensee's proposed plan, with respect to training personnel in the use and the provision of 

alternate power to the primary and backup instrument channels, including the approach to 

identifying the population to be trained, appears to be consistent with NEI 12-02, as endorsed 

by the ISG. 
-26-

3.13 Programmatic Controls: Procedures 

Attachment 2 of Order EA-12-051 states, in part, that 

Procedures shall be established and maintained for the testing, calibration, and 

use of the primary and backup spent fuel pool instrument channels. 

NEI 12-02 states, in part, that 

Procedures will be developed using guidelines and vendor instructions to 

address the maintenance, operation and abnormal response issues associated 

with the new SFP instrumentation. 

In its OIP, the licensee stated that procedures for maintenance and testing would be developed 

using regulatory guidelines and vendor instructions. 

In its letter dated August 19, 2013, the licensee stated, in part, that 

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 

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 END processes and 

procedures. "-

These procedures will contain the technical objectives associated with the 

maintenance, inspection, testing, repair and utilization of the SFPI. Portable 

instrumentation is not utilized. Both primary and backup SFPI channels 

incorporate permanent hard-wired installation. 

The NRC staff has concerns with the licensee's lack of information regarding the procedures 

that should be established and maintained for the testing, calibration, and use of the primary 

and backup spent fuel pool instrument channels notes that the information regarding the 

procedures for the testing, calibration,· and use. The staff has identified this request as: 
- 27-

RAI #17 

Please provide a list of the procedures addressing operation (both normal and abnormal 

response), calibration, test, maintenance, and inspection that will be developed for use of 

the SFP instrumentation. The licensee is requested to include a brief description of the 

specific technical objectives to be achieved within each procedure. 

(This information was previously requested as RAI-10 in the NRC letter dated July 18, 2013. 

However, based on feedback from the licensees, it has been revised as above.) 

3.14 Programmatic Controls: Testing and Calibration 

Attachment 2 of Order EA-12-051 states, in part, that 

Processes shall be established and maintained for scheduling and implementing 

necessary testing and calibration of the primary and backup spent fuel pool level 

instrument channels to maintain the instrument channels at the design accuracy. 

NEI 12-02 states, in part, that 

Processes shall be established and maintained for scheduling and implementing 

necessary testing and calibration of the primary and backup SFP level instrument 

channels to maintain the instrument channels at the design accuracy. The 

testing and calibration of the instrumentation shall be consistent with vendor 

recommendations or other documented basis. 

In its OIP, the licensee stated the station procedures and preventive maintenance tasks will be 

developed to perform required surveillance testing, calibration, backup battery maintenance, 

functional checks, and visual inspections of the probes. 

In its letter dated August 19, 2013, the licensee stated, in part, that 

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 
- 28-

appropriate frequencies established equivalent to or more frequently than 

existing spent fuel pool instrumentation. 

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. 

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. 

In its letter dated August 19, 2013, the licensee stated, in part, that 

SFPI channel/equipment maintenance/preventative maintenance and testing 

program requirements to ensure design and system readiness are planned to be 

established in accordance with ENO'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. 

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 .coup leg 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. 

In its letter dated August 19, 2013, the licensee also provided a table with compensatory actions 

for unlikely extended out-of-service events. 

The NRC staff notes the licensee proposed approach regarding compensatory actions with 

respect to testing and calibration appears to be consistent with NEI 12-02, as endorsed by the 

ISG. The staff has concerns regarding the scheduling and implementing necessary testing and 

calibration of the primary and backup SFP level instrument channels to maintain the instrument 

channels at the design accuracy. The staff has identified this request as: 
-29-

RAI #18 

Please provide 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. 

3.15 Instrument Reliability 

NEI 12-02 states, in part, that 

A spent fuel pool level instrument channel is considered reliable when the 

instrument channel satisfies the design .elements listed in Section 3 [Instrument 

Design Features] of this guidance and the plant operator has fully implemented 

the programmatic features listed in Section 4 [Program Features]. 

\ 

In its OIP, the licensee stated the reliability of the primary and backup instrument channels 

would be assured by conformance with the guidelines of NRC JLD-ISG-2012-03 Revision 0 and 

NEI 12-02 Revision 1. 

Upon acceptable resolution of the RAis noted above, the NRC staff will be able to make a 

conclusion regarding the reliability of the SFP instrumentation. 

4.0 CONCLUSION 

The NRC staff is unable to complete its evaluation regarding the acceptability of the licensee's 

plans for implementing the requirements of Order EA-12-051 due to the need for additional 

information as described above. The staff will issue an evaluation with its conclusion after the 

licensee has provided the requested information. 
I 

- 2 -

status updates, as the information becomes available. However, the staff requests that all 

information be provided by March 31, 2015, to ensure that any issues are resolved prior to the 

date by which the licensee must complete full implementation of Order EA-12-051. The 

licensee should adjust its schedule for providing information to ensure that all this information is 

provided by the requested date. 

If you have any questions regarding this letter, please contact me at 301-415-8371 or via e-mail 

at Mahesh.Chawla@ nrc.gov. 

Sincerely, 

/RAJ 

Mahesh Chawla, Project Manager 

Plant Licensing Branch 111-1 

Division of Operating Reactor Licensing 

Office of Nuclear Reactor Regulation 

/ Docket No. 50-255 

[ 

Enclosure: 

. Interim Staff Evaluation and 

' Request for Additional Information 

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