ML20044F157

Proposed Amend PCOL-93/04 to License NPF-29,revising TS 4.8.3.1.2 & 4.8.3.2.2 to Remove Operability Requirements for auto-test Feature of Load Shedding & Sequencing (LSS) Sys & Increase AOT for Inoperable LSS Sys from Eight to 24 H

ML20044F157
Person / Time
Site:	Grand Gulf
Issue date:	05/20/1993
From:	Hutchinson C ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20044F158	List: ML20044F157 ML20044F160
References
GNRO-93-00058, GNRO-93-58, PCOL-93-04, PCOL-93-4, NUDOCS 9305270056
Download: ML20044F157 (10)

Text

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A T Entergy e y g -a - i=-

Operations u: ' ..r :

May 20,1993 U.S. Nuclear Regulatory Commission Mail Station P1-37 i Washington, D.C. 20555 Attention: Document Control Desk

Subject:

Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29 Load Shedding and Sequencing System Technical Specification Changes Proposed Amendment to the Operating License (PCOL-93/04)

GNRO-93/00058 Gentlemen Entergy Operations, Inc. is submitting by this letter a proposed amendment to the Grand Gulf Nuclear Station (GGNS)

Operating License. This proposed change requests changes to the Onsite Power Distribution Systems - Distribution, for both the Operating and Shutdown Technical Specifications (TS). The proposed changes remove operability requirements for the auto-test feature of the Load Shedding and Sequencing (LSS) System and increase the allowed outage time (AOT) for an inoperable LSS system from eight to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. These changes are consistent with the requirements stipulated in the Improved Standard Technical Specifications, NUREG 1434, Revision 0; however, Entergy considers this a plant-specific change because the LSS system design utilized at GGNS is unique among BWRs.

Problems with the Division II LSS system's auto-test feature resulted in discretionary enforcement action in August, 1991.

A temporary waiver of compliance was granted allowing ,

continued operation with the auto-test function inoperable  !

from August 15, 1991 through August 31, 1991. The waiver was granted primarily on the basis that the auto-test feature is i pot essential for the LSS system to perfoon its safety I function. Entergy Operations, Inc. has evaluated several hardware options for the long term resolution of this problem, including replacement of the system. Although none of the i I

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Eby 20, 1993 GNRO-93/00058 Page 2 of 4 hardware options proved to be cost effective, we do believe that eliminating the technical specification requirements on i the self-test feature of the LSS system would provide an .

equally effective resolution at significantly less cost and l would result in no net reduction in safety. Other means of t surveilling the system are available and have proven to be ,

effective in the past. We have therefore decided to pursue {

this option.  ;

Attachment 2 provides a detailed description of the proposed changes, justification, and the No Significant Hazards  !

Considerations. Attachment 3 is a copy of the marked-up TS and TS bases pages, and Attachment 4 is an information copy of  ;

the proposed TS.  ;

In accordance with the provisions of 10CFR50.4, the signed original of the requested smendment is enclosed. This amsndment request has been reviewed and accepted by the Plant Safety Review Committee and the Safety Review Committee.

Based on the guidelines in 10CFR50.92, Entergy Operations has l concluded that this proposed amendment involves no significant ,

hazards considerations. Attachment 2 details the basis for i this determination.

Yours truly,

. J lI a 4W C. R. chinson Vice President, Operations GGNS  ;

i WEL/ams attachments: 1. Aft'rmation per 10CFR50.30  :

2. GGNS PCOL-93/04 '

3. Mark-up of Affected Technical Specification ,

Pages l

4. Proposed Technical Specifications Pages -

Information Only .

cc: (See Next Page)

G9304301 - 2 1

r May 20. 1993 GNRO-93/00058 i

Page 3 of 4 cc: Mr. R. H. Bernhard (w/a)

Mr. H. W. Keiser (w/a)

Mr. R. B. McGehee (w/a) <

Mr. N. S. Reynolds (w/a)

Mr. H. L. Thomas (w/o)

Mr. Stewart D. Ebneter (w/a)

Regional Administrator U.S. Nuclear Regulatory Commission Region II 101 Marietta St., N.W., Suite 2900 Atlanta, Georgia 30323 Mr. P. W. O'Connor, Project Manager (w/2)

Office of Nuclear Reactor Regulation ,

U.S. Nuclear Regulatory Commission Mail Stop 13H3 Washington, D.C. 20555 Dr. Alton B. Cobb (w/a)

State Health Officer State Board of Health P.O. Box 1700 Jackson, Mississippi 39205 -

6 G9304301 - 3

Attachment 1 to GNRO-93/00058

'Pago 1 of'1. j

• l BEFORE THE i

UNITED STATES NUCLEAR REGULATORY COMMISSION .l LICENSE NO. NPF-29 +

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DOCKET NO. 50-416 b

IN THE MATTER OF  !

MISSISSIPPI POWER E LIGHT COMPANY and .;

SYSTEK ENERGY RESOURCES, INC. >

and  ;

SOUTH MISSISSIPPI ELECTRIC POWER ASSOCIATION  :'

and ENTERGY OPERATIONS, INC. l l

AFFIRMATION i s

I, C. R. Hutchinson, being duly sworn, state that I am Vice '

President, Operations GGNS of Entergy Operations, Inc.; that l on behalf of Entergy Operations, Inc., System Energy '

Resources, Inc., and South Mississippi Electric Power j Association I am authorized by Entergy Operations, Inc. to i sign and file with the Nuclear Regulatory Cosimission, this l application for amendment of the Operating License of the }

Grand Gulf Nuclear Station; that I signed this application i-as Vice President, Operations GGNS of Entergy Operations, [

Inc.; and that the statements made and the matters set forth  !

therein are true and correct to the best of my kn ledge,. l information and belief. ,f i mv C . "R . Hutchinson -

STATE OF MISSISSIPPI COUNTY OF CLAIBORNE ,

. i.

SUBSCRIBED AND SWORN-TO before me, a Notary Publfc,.in and  ;

for the County and' State.above named, this .SBtr day of  !

Y7?a.44.- , 1993.  !

I (SEAL) l My Commission Expires November 11,1996 Mv" OMNotRfy w //Pubilc f & y I

{

My commission expires: j G9304301 - 4

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Attachment 2 to GNRO-93/00058

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PROPOSED CHANGE TO THE OPERATING LICENSE l

LOAD SHEDDING AND SEQUENCING SYSTEM j (GGNS PCOL 93/04) j i

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- . l Grand Gulf Nuclear Station Attachment 2 to GNRO-93/00058 l 4

PCOL 93/04 Page 2 of 6  ;

A.

SUBJECT:

Load Shedding and Sequencing System i Technical Specification: 4.8.3.1.2 and 4.8.3.2.2 Affected Pages: 3/4 8-16 and 3/4 8-18  :

B. DISCUSSION:

The Load shedding and sequencing (LSS) system is utilized during a LOCA and/or bus j undervoltage (BUV) condition to disconnect (shed) and connect, automatically in i sequence, loads on the respective Class 1E buses. Through appropriate coincident i logic, the system initiates operation of the diesel generators, selects and provides logic .

for the sequential loading of the vital busses to minimize stress on the diesel engine. .i The LSS system monitors bus voltages, offsite power sources and accident conditions  !

on Div I and Div II. The system consists of two solid state LSS panels, one for each l division. These panels contain separate sequencers with both manual and automatic  :

test capability. All system logic and timing functions utilize solid state circuits, with I

buffering relays used for input and output.  ;

Technical Specification 3/4.8.3, "On-Site Power Distribution Systems", specifies  ;

operability requirements for the Division 1 and 2 Load Shedding and Sequencing (LSS)  ;

systems. Surveillance Requirements 4.8.3.1.2.a (operating) and 4.8.3.2.2.a  :

(shutdown) require that the LSS panels be demonstrated operable i

"At least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> by determining that the auto-test system is operating and is not indicating a faulted condition."

With the auto-test feature inoperable, the current TS require the plant to enter a  ;

shutdown condition even though the LSS system is capable of performing its specified i safety function. This proposed amendment to the Grand Gulf (GGNS) Technical i Specifications (TS) requests removal of the Surveillance Requirement for the auto-test  ;

system of the LSS panels. Editorial changes to Surveillance Requirements 4.8.3.1.2 [

and 4.8.3.2.2 are proposed to reflect a single surveillance requirement. Based on the  !

LSS system design and our experience with the system, many of the faults identified  ;

on the LSS panel do not represent a failure of the functional capabilities of the LSS 1 system, but rather malfunctions of the auto-test feature itself. The auto test feature will continue to be utilized to monitor the LSS system and to diagnose LSS system ,

problems. Operability would be based on the LSS system's ability to perform its intended safety function with rcasonable assurance and reliability versus the condition of the auto-test feature. This change is consistent with the improved Standard '

Technical Specifications presented in NUREG 1434 IRef. 3].

Technical Specifications 3/4.8.3, "On-Site Power Distribution Systems", s,necifies  !

ACTION statements for situations where either Division 1 or 2 Load Shedding and i Sequencing (LSS) system is inoperable. Action is taken in accordance with TS 3.8.3.1  ;

ACTION a.3 which states: .i i'

Grand Gulf Nuclear Station Attachment 2 to GNRO-93/00058 +

PCOL 93/04 Page 3 of 6 i "With one of the above required load shedding and sequencing panels inoperable, restore the inoperable panel to OPERABLE status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or be in at least f HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the i following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />."  ;

This proposed amendment to the Grand Gulf (GGNS) Technical Specifications (TS) .!

increases the allowed outage time (AOT) for an inoperable load shedding and  ;

sequencing (LSS) panel from eight hours to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Because the LSS panel l comprises an intricate electronic system, the proposed 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> AOT would allow the ,

LSS panel's vendor to be contacted and utilized in troubleshooting LSS system  !

problems, thereby allowing the system to be retumed to service, possibly avoiding unnecessary plant shutdowns. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> AOT provides a period of time to correct LSS system problems commensurate with the importance of maintaining system i operability. The AOT also ensures that the probability of an accident requiring LSS  :

system operability occurring during periods the system is inoperable is minimal. This  ;

change is also consistent with the improved Standard Technical Specifications presented in NUREG 1434 [Ref. 3] recognizing this represents a change in the bracketed AOT in NUREG 1434.  !

i C. JUSTIFICATION:

The auto-test system is a non-safety related feature of the LSS system that monitors ,

LSS circuit operation from the ele *.ronics that process the input signals up to the  ;

output relays of the LSS. The auto-test feature is utilized as a diagnostic toolin i identifying LSS system malfunctions. The auto-test feature performs a check of the l panel's electronics approximately once every 1.5 seconds. If a fault is detected, the i logic displays the step number of the failed test on the control panel, interrupts the  ;

auto-test blocking it from further operation, and actuates a control room annunciator {

alerting the control room operator that the auto-test has detected an apparent fault in  ;

the panel's logic. The LSS system's control panel is used in conjunction with manual  ;

tests to identify the source of the fault. The auto-test is also terminated upon receipt  !

of a valid LSS actuation signal. Similarly, failure of the auto-test will not affect the ability of the LSS system to perform its safety function.

The manual LSS logic test retained in Surveillance Requirement 4.8.3.1.2 and j 4.8.3.2.2 provides for simulating actual LSS panel operating conditions by simulating l real panet inputs utilizing test switches on the control panel, and verifying system status by observing control panelindicators. Although the manual LSS logic test does }

not examine all of the LSS logic circuitry, the test is equivalent to testing of I comparable equipment which cannot be actuated during plant operation. This manual i LSS logic test, in conjunction with 18-month surveillances performed per TSs 4.3.3.1, ,

4.3.3.2, 4.8.1.1.2.d.4.a.2, 4.8.1.1.2.d.7.a.2 and 4.8.1.1.2.d.15, provide a  ;

comprehensive test of the LSS logic system and are sufficient to demonstrate LSS I system operability. Therefore, removal of operability requirements for the auto-test l feature of the LSS system is justified.  ;

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l Grand Gulf Nuclear Station Attachment 2 to GNRO-93/00058 PCOL 93/04 Page 4 of 6 LCO 3.8.3.1, Action a.1, currently requires the LSS system to be restored to -

OPERABLE in eight hours or place the unit in a conc. tion where the LCO no longer

applies (MODE 4). The Grand Gulf Safety analyses assume that two of the three l electrical divisions perform the design basis function of the electrical system. The LSS system functions to connect ESF loads to the associated on-site power source required by TS 3.8.1. With the LSS inoperable, redundancy in the on-site power system is ,

potentially lost. This condition is similar to the degree of degradation described by level 3 in Regulatory Guide 1.93 [Ref.41. Level 3 corresponds to the condition where j the available off-site and on-site AC sources are each one less than the LCO (i.e.,

GGNS LCO 3.8.1). This condition would result in the complete loss of an ESF division i if the remaining off-site source is lost. According to Regulatory Guide 1.93 (RG 1.93),  ;

operation at level 3 may continue for a period not to exceed 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. Although  !

i similar to level 3 in that neither an off-site or on-site source is immediately accessible following loss of the functioning power source,inoperability of a single LSS system  ;

represents a notable safety improvement over level 3 for the following reasons:

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l o LSS system failure does not prevent manualloading of ESF loads to either an l available off-site source or the associated diesel generator.

o Operator training and procedures direct the manual starting and loading of I safety equipment in the unlikely event the LSS system fails completely.

• o The GGNS preferred power system design includes three independent circuits ,

capable of supplying power to the ESF busses.

o The demonstrated overall outage rates (through 1991) of 1.01 and 1.63 r outages / year /100 miles of the 500 and 115 kV lines, respectively, tends confi- ,

dence to the expectation the preferred power source is available at all times.

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Therefore, the proposed 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> AOT represents an adequate balance between the  !

risks associated with immediate shutdown and continued operation and ensures that j the probability of an accident requiring LSS system operability occurring during periods i the system is inoperable is minimal.  !

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l D. NO SIGNIFICANT HAZARDS CONSIDERATIONS:  !

i I This proposed amendment to the Grand Gulf Nuclear Station (GGNS) Technical

] Specifications (TS) removes of the Surveillance Requirement for the auto-test system  !

of the load shedding and sequencing (LSS) panels (4.8.3.1.2.a and 4.8.3.2.2.a) and l increases the allowed outage time (AOT) for an inoperable LSS panel (ACTION .

! 3.8.3.1.a.3) from eight hours to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Editorial changes to Surveillance  !

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Requirements 4.8.3.1.2 and 4.8.3.2.2 are proposed to reflect a single surveillance.

The Commission has provided standards for determining whether a no significant }

hazards consideration exists as stated in 10CFR50.92(c). A proposed amendment to i an operating license involves a no significant hazards consideration if operation of the [

q facility in accordance with the proposed amendment would not: (1) involve a j d

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. Grand Gulf Nuclear Station Attachment 2 to GNRO-93/00058 j

' PCOL 93/04 Page 5 of 6 - ;

f significant increase in the probability or consequences of an accident previously i evaluated; or (2) create the possibility of a new or different kind of accident from any  !

accident previously evaluated; or (3) involve a significant reduction in a margin of  !

safety. l Entergy Operations Inc. has evaluated the no significant hazards considerations in its l request for a license amendment. In accordance with 10CFR50.91(a), Entergy  ;

Operations Inc. is providing the analysis of the proposed amendment against the three j standards in 10CFR50.92(c). A description of the no significant hazards considerations ,

determination follows ,

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1. The proposed changes do not significantly increase the probability or consequences of an accident previously evaluated. l The auto-test feature functions to provide additional assurance the LSS system is l capable of responding to valid accident conditions and performing its specified l safety function. The auto-test feature is independent of this safety function and is terminated upon receipt of a valid LSS actuation signal. In fact, disabling the auto-test feature has no affect on the LSS system's ability to perform its specified safety  :

function. The manual LSS logic test retained in Survei!!ance Requirement 4.8.3.1.2 l and 4.8.3.2.2 provides for simulating actual LSS panel operating conditions by  ;

simulating real panelinputs utilizing test switches on the control panel, and i verifying system status by observing control panet indicators. Although the manual  :

LSS logic test does not examine all of the LSS logic circuitry, it is equivalent to  ;

testing of comparable equipment which cannot be actuated during plant operation.  ;

This test, in conjunction with surveillances performed per TS 4.8.1.1.2.d.4.a.2,  !

4.8.1.1.2.d.7.a.2 and 4.8.1.1.2.d.15, is sufficient to demonstrate LSS system i operability. Therefore, removal of the auto-test feature from the Technical i Specifications requirements for LSS system operability does not significantly

• increase the probability or consequences of an accident previously evaluated. ,

No safety-related equipment or function will be altered as a result of this change.

The increase in the allowed outage time from eight hours to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provides a  :

period of time to correct LSS system problems commensurate with the importance of maintaining system operability. This change has no influence or impact on the ,

probability or consequences of any accident or malfunction evaluated in the GGNS Updated Final Safety Analysis Report (UFSAR) (Reference 2]. No accident or {

malfunctions evaluated are affected; therefore, the consequences of these have not significantly increased.

i Based on the above, the proposed changes do not significantly increase the  !

probability or consequences of any accident previously evaluated.

2. The proposed changes would not create the possibility of a new or different kind of f accident from any previous analyzed. J No new plant equipment or new modes of operation or accident modes are introduced or created by removing the auto-test feature from the TS. The auto-

i Grand Gulf Nuclear Station Attachment 2 to GNRO-93/00058  :

PCOL 93/04 Page 6 of 6 f test feature cannot, by its design, initiate or block an LSS system function. [

Disabling the auto-test feature cannot initiate or block an LSS function. Increasing 1 the AOT to from eight to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> has no influence on, nor does it contribute in l any way, to the possibility of a new or different kind of accident or malfunction i from those previously analyzed. As stated above, no safety-related equipment or safety functions are altered as a result of these changes. i Therefore, the proposed changes do not create the possibility of a new or different

• kind of accident from any accident previously analyzed. .

3. The proposed changes do not involve a significant reduction in a margin of safety. .f l

The function of the auto-test feature is to provide a level of assurance that the LSS - l system will perform its safety function when required. Continued use of the auto-  !

test feature, the proven reliability of the LSS system, and the system testing  !

retained in the TS, adequately establish operability of the LSS system. Removal of  !

the auto-test feature from the TS operability requirements does not affect the  !

system's ability to perform its safety function when required and, therefore, does  !

not involve a significant reduction in a margin of safety. l t

The proposed 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> AOT for the LSS system ensures that the probability of an >

accident requiring LSS system operability occurring during periods the system is inoperable is minimal. The margin of safety afforded by the proposed AOT is not  !

significantly less than that provided by the current eight hour AOT. Therefore the {

margin of safety provided by the current TS is not significantly reduced. i i

Therefore, the proposed changes do not result in a significant reduction in a margin [

of safety. }

t Based on the above evaluation, operation in accordance with the proposed amendment [

involves no significant hazards considerations. 'j

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REFERENCES:

1. Grand Gulf Nuclear Station Unit 1 Technical Specifications and Bases, Updated l through Amendment 106

2. Grand Gulf Nuclear Station Final Safety Analysis Report, Updated through' j Revision 7, Chapters 8 and 15.  !

3. NUREG 1434, Standard Technical Specifications, General Electric BWR/6 Plants, l

Revision 0, dated September 29,1992.  !

4. Regulatory Guide 1.93, Availability of Electric Power Sources, December 1974. j t

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