IR 05000352/1990003

Insp Repts 50-352/90-03 & 50-353/90-03 on 900116-19.No Violations Noted.Major Areas Inspected:Design & Surveillance Program for Compliance W/Atws as Described in 10CFR50.62 & NUREG-0991,SSER 9

ML20055C311
Person / Time
Site:	Limerick
Issue date:	02/11/1990
From:	Blumberg N, Finkel A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML20055C310	List: IR 05000352/1990003 ML20055C309
References
RTR-NUREG-0991, RTR-NUREG-991 50-352-90-03, 50-352-90-3, 50-353-90-03, 50-353-90-3, NUDOCS 9003020049
Download: ML20055C311 (7)

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U. S. NUCLEAR REGULATORY COMMISSION

REGION I

Report Nos. 50-352/90-03 50-353/90-03 Docket Nos. 50-352 50-353 License Nos. NPF-39 NPF-83 Priority Category C Licensee: Philadelphia Electric Company 2301 Market Street Philadelphia, Pennsylvania 19101

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Facility Name: Limerick Nuclear Generating Station, Units 1 and 2 Inspection At: Limerick, Pennsylvania Inspection Conducted: January 16-19, 1990 Inspectors: O ~ f~ b A.Finkel,SefiorReactorEngineer date <

Approved by A * 7 Hbb h . B'umberg, Chief, Operatidnal Programs date Section, OB, DRS Inspection Summary: Announced inspection on January 16-19, 1990 (50-352/90-03 and 50-353/90-03)

Areas Inspected: An inspection was performed to evaluate Limerick Nuclear Generating Station, Units I and 2 design and surveillance program for compliante with the Anticipated Transients Without Scram (ATWS) as described in 10 CFR 50.62 and Safety Evaluation Report (SER) NUREG-0991, Supplement N .

Results: Limerick Nuclear Generating Station, Units 1 and 2 has installed the I- design and implemented a surveillance and test program that complies with its requirements as described in Safety Evaluation Report NUREG-0991 Supplement N , August 1989 and the ATWS 10 CFR 50.62 requirement. In addition, the inspector verified through inspection of the installation that the ATWS system components were installed as a class 1E system which exceeds the requirements of 10 CFR 50.62. The inspector also verified that surveillance procedores have been written and issued for this system. The inspector did not identify any violations or deviations during this inspectio Sb$ $@@Q4 (g 4 82

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DETAILS l-1.0 Persons Contacted Philadelphia Electric Company l R. George, Engineering Specialties E. Grant, Licensing Engineer H. Hansell, Senior Engineer Risk Assessment

• J. Keenan, Nuclear Quality Assurance Engineer M. Leahy, Branch Head Engineering D. Maley, Engineering A. Marie, Branch Head, Risk Assessment

• L. Marabella, Reactor Engineering

• M. McCormick, Jr. , Plant Manager

• Rekito Licensing Engineer

• T. Shea, Maintenance /I&C Engineering United States Nuclear Regulatory Commission L. Scholl, Resident Inspector M. Evans, Resident Inspector The inspector also held discussions with other licensee personnel during the course of this inspectio ,

• Denotes those present at the exit meeting on January 19, 1990.

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2.0 Inspection Scope (525020)

The scope of'this inspection was to determine if the Anticipated Transients Without' Scram (ATWS) design as described in Safety Evaluation Report (NUREG-0991, Supplement No. 9) has been implemented at the Limerick -

Generating Station, Units 1 and 2. The documents reviewed by the inspector-during this inspection are listed in Attachment A of this repor .1 Redundant Reactivity Control System (RRCS)

The RRCS consists of inputs from the reactor pressure and reactor

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water level sensors, logic, power supplies, control room cabinets, and instrumentation to initiate the protection actions to mitigate an ATWS event. The protection actions of the RRCS includes:

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Alternate Rod Injection (ARI)

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Recirculation Pump Trip (RPT)

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Feedwater Runback and Standby Liquid Control System (SLCS)

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The RRCS is independent from the reactor trip syste It is a two divisional safety related system with either division capable of initiating protective actions when both input channels A and B within a division are trippe The ATWS protective actions can also be manually initiated in the control room by depressing two push buttons (tripping both channels A and B) in the same division, j The inspector reviewed the logic circuit drawings, test data and performed a walk down of the installed system to verify the Unit 1 -

and 2 installations are as designe [ 2. Alternate Rod Injection System (ARI) ,

The ATWS rule does not require the ARI system to be safety grade, but at this site the ARI system (a subsystem of the RRCS) has been installed as a class IE system. It is electrically diverse and independent from the reactor trip system and was installed to meet the requirement of IEEE Standard 279-1971, " Criteria for Protection Systems for Nuclear ,

Power Generating Stations." The ARI system has redundant scram I air header exhaust valve,. The initiation and control circuits are redundant thus the ARI performs a function redundant to the backup scram syste In addition to being physically separated from the existing protection system, the ARI is required to be diverse from it

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also. To achieve this requirement Limerick's ARI system uses energize-to-function valves instead of deenergize-to-function valves as is used in the existing protection system. Also the ARI system has DC powered valves and logic instead of AC powered valves and logic which is the design of the existing protection syste During the system walkdown of the ARI design, the inspector i/erified that the licensee complied with the DC system

,. criteri The walkdown of the ARI system also verified that I

the detection logic circuitries, power supplies and final actuated devices are independent from the presently installed reactor trip syste The ARI design appears to minimize inedvertent challenges to l other safety systems. Limerick's ARI system has installed ,

I redundant channels in each division. Both channels A and B must be tripped to initiate the protection actions. A manual

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initiation also requires arming the switch and depressing two push buttons to initiate the actio To assure that the ARI system performed as required, the inspector reviewed the surveillance test procedure and data that tested this system (ST-2-042-100-2, " Redundant Reactivity Control System Logic System Functional Test"). The procedures and test data reviewed indicated that the ARI system performed as designe >

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2. _ Recirculation Pump Trip (RPT)  ;

The RPT is a subsystem of the Redundant Reactivity Control i System (RRCS). It is a class IE system and was designed and '

installed to meet IEEE 279-1971. The RPT is redundant with i two trains. The diversity of the design is that the RPT system ;

uses energize-to-function logic whereas the Reactor Trip System i (RTS) is designed to deenergize-to-function logic. Also the >

sensors, trip units, and power supplies are diverse and .

independent from the RTS. The RPT system is a redundant 2 out '

of 4 logic arrangement. Each level and pressure instrument -

can be tested during plant operatio The RPT system is continuously self-tested as part of the RRCS, An analog trip module failure, an out-of-calibration :

condition, or a lack of system continuity condition is  !

annunciated in the control room. To verify the function of ;

the RPT :ystem, procedure ST-2-042-200-2 is used during the '

surveillance test program. The inspector reviewed the surveillance procedure and verified that the requirements of :

Safety Esaluation Report, NUREG-0991, Supplement No. 9 were ,1 i

incorporated into the doc,ument. A review of the test data '

documented by ST-2-042-100-2 verified that the RPT system '

was operating and within its design criteri . Standby Liquid Control System (SLCS)

The Standby Liquid Control System (SLCS) consists of a chemical storage tank, pumps, valves and associated piping. The system ,

is normally maintained in a standby mode and maybe manually !

initiated by the control room operato The RRCS provides an automatic initiation of the SLCS injection into the core. The major components of the Standby Liquid Control System that _were inspected by the inspector were:

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Storage Tank '

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Tank Solution

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Injection Pumps -

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Explosive Valves

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After verifying that the SLCS installation was installed as designed in (General Electric drawing 761E239AD, Standby Liquid Control System and Bechtel drawing M-48, P and ID Standby Liquid Control), the inspector reviewed the surveillance test procedures and data for compliance with the requirements of Technical Specification paragraph 4.1.5, Amendment No. 2 The surveillance procedures and test results for the monthly, quarterly, and eighteen month tests were in accordance with its Technical Specification paragraph 4.1.5, criteri ?

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3.0 Conclusions 4 The inspection review of the Limerick Unit 1 and 2 installation and surveillance test procedures and data concluded that the ARI, ATWS/RPT, SLCS installation, and the surveillance program comply with

the requirements of its Technical Specification and Safety Evaluation i Report, NUREG-0991, Supplement No. 9, August, 1989. The system l

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components were well maintained and the personnel were knowledgeable of their procedure requirement .0 Exit Meetino Licensee management was informed of the scope and purpose of the inspection at an entrance meeting conducted on January 16, 199 An exit meeting was conducted on January 19, 1990 (see paragraph I for attendees) at which time the results of the inspection was presen At no time during the inspection uid the inspector provide written material to the licensee nor did the licensee indicate that areas covered by this inspection contained proprietary it. formation, f P

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ATTACHMENT A ,

1.0 NRC Documentation

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Safety Evaluation Report, NUREG-0991, Supplement No. 9, August, 1989, Limerick Generating Station, Units 1 and 2, Docket Nos. 50-352 and 50-35 '

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Technical Specifications

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NRC Memorandum, April 10, 1989, " Diversity Requirements of ATWS Rule (10 CFR 50.62) for BWR Plants." Issued by the Instrumentation and Control Systems Branch, Division of Engineering and System Technolog ::t!F Standard 279-1971, " Criteria for Protection Systems for Nuclear Power Generating Stations."

2.0 Limerick Unit 1 and 2 Documentation 2.1 Surveillance Procedures

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ST-2-042-100-2, " Redundant Reactivity Control System Logic System Functional Test." Test frequency is at refueling or initiating even ,

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ST-3-048-230-1, "SLC Pump, Valve, and Flow Test." Test frequency is 3 months or initiating event '

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ST-6-048-450-1, "SLC Lineup Verification."- Test frequency is monthly or initiating event ,

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ST-6-107-590-1, " Daily Surveillance Log /0PCONS 1,_2, 3."

2.2 Drawings

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761E239AD, General Electric's P and ID, " Standby Liquid Control System."

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M-48, Bechtel P and ID, " Standby Liquid Control, Unit 2."

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. , . . * 1 a-POST INSPECTION SALP DATA SHEET Facility: Limerick Unit 1&2 2. Inspector: A. Finkel

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l 50-352/90-03 i'

Docket No./ Report No.

50-353/90-03 4. Inspection Dates: 1/16-19/90

. Functions 1 Area: ATWS Rule 6. Category Rating (1,2 or 3): 2_ Inspection Hours For This Functional Area: 32  ;

' The design of the ATWS rule 10 CFR 50.62 at Limerick Units 1 and 2 exceeds the rule criteria. The ATWS design is a class 1E system and i complies with the ATWS rule including the subject of diversity. The ,

i system engineer for this system was well informed and ut.derstood the  !

diversity rubjec ! Surveillance procedures are issued which comply with the SER requirements for this system. Surveillance testing is performed and documented as ,

required by the TS, SER, and ATWS Rul ]

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For this inspection the licensee is considered to be a Category !

Submitted by Inspector (Sign /date)

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10. Approved by DRS Section Chie !

a (Sign /date)

l DISTRIBUTION:

DRS Files

DRP Section Chief for the Reactor Inspected

Sr. Resident Inspector

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