ML16292A811

Response to Disputed Non-Cited Violation; LaSalle County Station, Units 1 and 2 - Inspection Report 05000373/2016007; 05000374/2016007

ML16292A811
Person / Time
Site:	LaSalle
Issue date:	10/17/2016
From:	Darrell Roberts Region 3 Administrator
To:	Bryan Hanson Exelon Generation Co, Exelon Nuclear
References
EA-16-155 IR 2016007
Download: ML16292A811 (7)

See also: IR 05000373/2016007

Text

UNITED STATES

NUCLEAR REGULATORY COMMISSION

REGION III

2443 WARRENVILLE RD. SUITE 210

LISLE, IL 60532-4352

October 17, 2016

EA-16-155

Mr. Bryan C. Hanson

Senior VP, Exelon Generation Company, LLC

President and CNO, Exelon Nuclear

4300 Winfield Road

Warrenville, IL 60555

SUBJECT: RESPONSE TO DISPUTED NON-CITED VIOLATION; LASALLE COUNTY

STATION, UNITS 1 AND 2 - INSPECTION REPORT 05000373/2016007;

05000374/2016007

Dear Mr. Hanson:

On July 22, 2016, Mr. William J. Trafton, Site Vice President, LaSalle County Station, provided

a response (Agencywide Documents Access and Management System [ADAMS] Accession

Number ML16204A307) to an U.S. Nuclear Regulatory Commission (NRC) inspection report

issued on June 22, 2016, concerning activities conducted at the LaSalle County Station.

Specifically, the July 22, 2016, letter contested one of the Non-Cited Violations (NCVs)

contained in the Inspection Report, namely NCV 05000373/2016007-04; 05000374/2016007-04,

Alternate Shutdown Procedures Failed to Ensure RCIC [Reactor Core Isolation Cooling] MOVs

[Motor Operated Valves] Supply Breakers Were Closed. By our letter (ML16231A395) dated

August 18, 2016, the NRC acknowledged Mr. Traftons letter and advised him that NRC staff was

evaluating his reply and would inform him of the results of our evaluation.

In the July 22, 2016, letter your staff stated that the NRC had inappropriately evaluated the

current Exelon Generating Company analysis and approach as a performance deficiency and

stated that the NCV should be rescinded. Your staff provided the following specific bases for

contesting the NCV:

1. The NRCs postulated fire-induced circuit failures involving shorts are outside the

published and accepted standards.

2. The valves identified by the NRC in the NCV [1(2)E51-F019 and 1E51-F059] do not

fall under the trip reset requirements since their function is not necessary to support

the systems fire safe shutdown capability.

The NRC conducted a detailed review of your response and the applicable regulatory

requirements, in accordance with Part I, Section 2.2.8, of the NRC Enforcement Manual. The

evaluation was conducted by a knowledgeable individual independent from the NRC staff in the

Division of Reactor Safety who originally identified the violation and issued the inspection report.

After careful consideration of the basis for your denial of the NCV, the NRC has determined that

B. Hanson

-2-

the NCV is valid as stated in the original inspection report. The NRC staff, in its independent

assessment, has determined that the issue qualifies as a performance deficiency due to the

published and accepted standards and the LaSalle Safety Evaluation Report, NUREG-0519,

which required the consideration of fire-induced circuit failures involving shorts. Details of the

evaluation are provided in the enclosure to this letter.

In accordance with Title 10 of the Code of Federal Regulations (10 CFR) 2.390, Public

Inspections, Exemptions, Requests for Withholding, of the NRC's Rules of Practice, a copy of

this letter, its enclosure, your staffs July 22, 2016 letter, and your response (if any) will be

available electronically for public inspection in the NRCs Public Document Room or from the

Publicly Available Records (PARS) component of the NRC's Agencywide Documents Access

and Management System (ADAMS). ADAMS is accessible from the NRC Web site at

http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).

Sincerely,

/RA/

Darrell J. Roberts

Deputy Regional Administrator

Docket Nos. 50-373; 50-374

License Nos. NPF-11; NPF-18

Enclosure:

Independent Assessment of LaSalle Contested Violation

cc: Distribution via LISTSERV

Independent Assessment of LaSalle Contested Violation

Enclosure

The independent assessment of the LaSalle County Station contested Non-Cited Violation

(NCV)05000373/2016007-04; 050i00374/2016007-04, Alternate Shutdown Procedures Failed

to Ensure RCIC [Reactor Core Isolation Cooling] MOVs [Motor Operated Valves] Supply

Breakers Were Closed, concluded that the NCV in the original inspection report was valid.

A review of the NCV is provided below.

The independent assessment included a review of the following documents:

Calculation L-004017, 250 Vdc Breaker Fuse Coordination for RCIC, Revision 000

Generic Letter 86-10, Implementation of Fire Protection Requirements, April 24, 1986

LaSalle County Station, Units 1 and 2 - Response to NRC Component Design Basis

Inspection, Inspection Report 05000373/2016007; 05000374/2016007, July 22, 2016

(ADAMS Accession No. ML16204A307)

Letter form S. Collins, NRC, to R. Beedle, Nuclear Energy Institute, Assessment of

NEI Concerns Regarding NRC Information Notice 92-18 Potential for Loss of

Remote Shutdown Capability During a Control Room Fire, March 11, 1997

(ADAMS Accession No. ML003716454)

Letter from M. Jeffers, NRC, to W. Trafton, LaSalle County Station, LaSalle County

Station Acknowledgment of Disputed Violation of NRC Inspection Report 05000373/2016007; 05000374/2016007, August 18, 2016 (ADAMS Accession No.

ML16231A395)

NRC Inspection Report 05000373/2016007; 05000374/2016007, LaSalle County

Station, Units 1 and 2 - NRC Component Design Bases Inspection, June 22, 2016

(ADAMS Accession No. ML16174A094)

NUREG-0519, Safety Evaluation Report Related to the Operation of LaSalle County

Station Units 1 and 2, March 1981

NUREG-0800, Standard Review Plan, July 1981

Operating Abnormal Procedure LOA-FX-101, Unit 1 Safe Shutdown with a Fire in

the Control Room or AEER, Revision 27

Operating Abnormal Procedure LOA-FX-201, Unit 2 Safe Shutdown with a Fire in

the Control Room or AEER, Revision 29

Title 10, Code of Federal Regulations, Part 50, Appendix R, Fire Protection Program

for Nuclear Power Facilities Operating Prior to January 1, 1979

In the July 22, 2016 letter, Exelon claimed that the valves identified by the NRC in the NCV

were not required to achieve and maintain safe shutdown; therefore, would not be required to

be proceduralized. Exelon further stated that the U.S. Nuclear Regulatory Commission (NRC)

had not identified or produced any documented requirement, position, or guidance applicable to

LaSalle County Station that specifically describes the additional short circuits they [the NRC] are

contending must be analyzed. Exelon also stated that, Absent a documented standard for

which it was reasonable for LaSalle to foresee, this issue does not qualify as a performance

deficiency.

2

Exelon disagreed with two of the NRCs key positions that formed the basis for the NCV.

Exelon stated that:

1. The NRC postulated fire-induced circuit failures involving shorts are outside the

published and accepted standards.

2. The valves identified by the NRC in the NCV [1(2)E51-F019 and 1E51-F059] do not

fall under the trip reset requirements since their function is not necessary to support

the systems fire safe shutdown capability.

Exelon Position 1

Exelons position is that the finding/non-cited violation is based on the NRC inspectors

postulating fire-induced circuit failures that are outside the scope of the current requirements or

any NRC endorsed industry guidance applicable to LaSalle County Station. Specifically, Exelon

stated that the inspectors identified short circuit cable lengths shorter than those analyzed in

calculation L-004017 (250 VDC Breaker Fuse Coordination For Reactor Core Isolation Cooling

(RCIC)) by postulating shorts between cables associated with the valves in question

(i.e., 1(2)E51-F019 or F059) and another valve from the same power source, or shorts between

cables associated with these valves and the ground, and cables associated with other valves

and the ground that would end up with a short circuit via the ground.

Exelon further stated that the NRC position on the methodology used in calculation L-004017

was based on Nuclear Energy Institute (NEI) Document 00-01, Guidance for Post-Fire Safe

Shutdown Circuit Analysis, which LaSalle is not currently committed to. Exelon stated that,

Neither during the inspection, nor in the inspection report, has the NRC provided reference to

any formal NRC guidance or endorsed industry document that supports their position that these

additional shorts need to be postulated. Exelon further stated that the NRC had not clearly

described their basis for the performance deficiency.

Response to Exelons Position 1

Section III.G.2 of Title 10 of the Code of Federal Regulations (CFR), Part 50, Appendix R

requires, in part, that, where cables or equipment, including associated non-safety circuits that

could prevent operation or cause maloperation due to hot shorts, open circuits, or shorts to

ground, of redundant trains of systems necessary to achieve and maintain hot shutdown

conditions are located within the same fire area outside of primary containment, one of the

following means of ensuring that one of the redundant trains is free of fire damage shall be

provided Further, for those fire areas not meeting the criteria of III.G.2 Sections III.G.3 and

III.L apply. Section III.L.7 states, in part, that, The safe shutdown equipment and systems for

each fire area shall be known to be isolated from associated non-safety circuits in the fire area

so that hot shorts, open circuits, or shorts to ground in the associated circuits will not prevent

operation of the safe shutdown equipment.

Plants licensed on or after January 1, 1979 (which includes LaSalle) are not required to meet

the requirements of Appendix R. The NRC staff reviewed these plants Fire Protection

Programs against the Standard Review Plan, NUREG-0800. The Standard Review Plan,

Section C.5c(7), contains nearly identical language to Section III.L.7 of Appendix R and states,

in part, that, The safe shutdown equipment and systems for each fire area should be known to

be isolated from associated circuits in the fire area so that hot shorts, open circuits, or shorts to

ground in the associated circuits will not prevent operation of the safe shutdown equipment.

3

The NRC developed Generic Letter 86-10, Implementation of Fire Protection Requirements, to

provide guidance and interpretations of Appendix R requirements. In section 5.3.1, Circuit

Failure Modes, the industry asked, What circuit failure modes must be considered in

identifying circuits associated by spurious actuation? The NRC responded, in part, that:

Sections III.G.2 and III.L.7 of Appendix R define the circuit failure modes as hot shorts,

open circuits, and shorts to ground. For consideration of spurious actuations, all

possible functional failure states must be evaluated, that is, the component could be

energized or de-energized by one or more of the above failure modes. Therefore,

valves could fail open or closed

The discussion of Generic Letter 86-10 is included here because the licensee specifically

referred to the generic letter in the July 22, 2016, response letter and the generic letter contains

the standard fire protection license condition that most, if not all, licensees previously adopted.

As such, the generic letter serves as a guidance document that is applicable to LaSalle County

Station.

The documents discussed above are included in order to show that the NRC staff position

regarding the need for licensees to consider hot shorts has been consistent for the past 35 years.

Regarding the LaSalle County Station licensing basis, the NRC discussed the need to consider

hot shorts in the LaSalle Safety Evaluation Report, NUREG-0519, dated March 1981. In

Section 9.5.3, Alternate Shutdown, of the Safety Evaluation Report, the NRC stated the

following:

(2)

For the design basis fire affecting the control room, cable spreading room, or remote

shutdown locations, we require electrical circuits between these control locations to be

sufficiently isolated so that both safe (hot and cold) shutdown capability will not be lost at

both locations, To assure this shutdown capability, we required the applicant to provide

the following information.

(d)

The results of an analysis that demonstrates that failure (open, ground, or hot

short) of each circuit identified will not affect the capability to achieve safe

shutdown.

In the licensees July 22, 2016, letter Exelon stated that the NRC based their conclusions

regarding the licensees methodology in calculation L-004017 on guidance provided in NEI 00-01.

However, in the Inspection Report 05000373/2016007; 05000374/2016007 write-up of the issue,

the NRC inspectors did not refer to NEI 00-01. The inspectors based their conclusion on

regulatory requirements and long-standing guidance.

The NRC staff has concluded, in its independent review of Exelon Position 1, that the fire-induced

circuit failures involving shorts that the NRC inspectors postulated in the inspection report are

within the published and accepted standards and that the basis for the performance deficiency is

valid. The preceding discussion provides a 35-year history of regulations and published staff

positions and guidance supporting the need for licensees to consider fire-induced hot shorts.

4

Exelon Position 2

Exelons position is that the valves identified by the NRC in the NCV [1(2)E51-F019 and

1E51-F059] do not fall under the trip reset requirements since their function is not necessary to

support the systems fire safe shutdown capability. The LaSalle Fire Protection Report credits

RCIC injection to the reactor pressure vessel to support fire safe shutdown. Therefore, as

described in the requirements above, it is not necessary to provide alternate instructions for

these valves in the procedures.

Response to Exelons Position 2

In the letter Exelon stated that, valves 1(2)E51-F019 and F059 do not impact the RCIC

injection into the reactor and are not essential for the RCIC system to perform this credited fire

safe shutdown function. Exelon stated that a spurious opening of valves 1(2)E51-F059 would

not divert water from the RCIC injection path because that valve is in series with the normally

closed 1(2)E51-F022 valve. They also stated that the RCIC minimum flow valve 1(2)E51-F019

is normally closed and should it spuriously open the RCIC system would be able to maintain the

desired flow rate.

The concern that the NRC inspectors documented in the inspection report was that the AOPs

did not include alternative instructions to verify that breakers for valves 1(2)E51-F019 and F059

would close in the event the circuit breakers open, preventing the MOVs from being operated.

If these valves could not be opened the centrifugal RCIC pump could be damaged as a result of

the pump deadheading and overheating in a very short period of time. This event could occur

upon startup of the RCIC turbine and pump and fire damage to circuits associated with valves

1(2)E51-F019 and F059 due to the hot shorts. The previous response to Exelon Position 1

validated that LaSalle was required to consider the impacts of hot shorts.

By not providing alternate instructions for the operators in the AOPs in the event that valves

1(2)E51-F019 and F059 could not be opened LaSalle did not ensure that fire damage to circuits

associated with those valves would not affect the capability to achieve safe shutdown. The

failure to open those valves could result in damage to the RCIC system, which is the credited

system for alternate shutdown from the remote shutdown panel.

The NRC staff has concluded, in its independent review of Exelon Position 2, that the valves

1(2)E51-F019 and 1E51-F059 do need to be considered under the trip reset requirements

because their failure to open could result in damage to RCIC system components and an

inability of the RCIC system to perform its safe shutdown actions.

Overall Conclusion

In conclusion, the NRC staff has determined that the issue qualifies as a performance deficiency

due to the published and accepted standards (as documented in Title 10 of the Code of Federal

Regulations (CFR), Part 50, Appendix R; NUREG-0800; and Generic Letter 86-10) and the

LaSalle Safety Evaluation Report, NUREG-0519, which required the consideration of fire-induced

circuit failures involving shorts. The regulatory requirements, staff positions, and guidance on

the need to consider fire-induced hot shorts have been well documented over the past 35 years.

B. Hanson

-2-

the NCV is valid as stated in the original inspection report. The NRC staff, in its independent

assessment, has determined that the issue qualifies as a performance deficiency due to the

published and accepted standards and the LaSalle Safety Evaluation Report, NUREG-0519,

which required the consideration of fire-induced circuit failures involving shorts. Details of the

evaluation are provided in the enclosure to this letter.

In accordance with Title 10 of the Code of Federal Regulations (10 CFR) 2.390, Public

Inspections, Exemptions, Requests for Withholding, of the NRC's Rules of Practice, a copy of

this letter, its enclosure, your staffs July 22, 2016 letter, and your response (if any) will be

available electronically for public inspection in the NRCs Public Document Room or from the

Publicly Available Records (PARS) component of the NRC's Agencywide Documents Access

and Management System (ADAMS). ADAMS is accessible from the NRC Web site at

http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).

Sincerely,

/RA/

Darrell J. Roberts

Deputy Regional Administrator

Docket Nos. 50-373; 50-374

License Nos. NPF-11; NPF-18

Enclosure:

Independent Assessment of LaSalle Contested Violation

cc: Distribution via LISTSERV

DISTRIBUTION:

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Carole Ariano

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ADAMS Accession Number ML16292A811

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DATE

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10/03/16

10/04/16

09/20/16

10/12/16

10/17/16

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