ML18101A673

Informs of Review of NRC Accident Sequence Precursor Analysis Re 940407 Reactor Trip & Safety Injection at Facility.Eops Used During 940407 Event Encl

ML18101A673
Person / Time
Site:	Salem
Issue date:	04/21/1995
From:	Hagan J Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML18101A674	List: ML18101A673 ML18101A675 ML18101A676 ML18101A677
References
LR-N95064, NUDOCS 9505020319
Download: ML18101A673 (7)

Text

J. Public Service Electric and Gas Company Joseph J. Hagan Public Service Electric and Gas Company P.O. Box 236, Hancocks Bridge, NJ 08038 609-339-1200 Vice President - Nuclear Operations A~R 211995 LR-N95064 Document Control Desk United states Nuclear Regulatory Commission Washington, DC 20555 Gentlemen:

REVIEW OF NRC ACCIDENT SEQUENCE PRECURSOR ANALYSIS SALEM UNIT NO. 1 DOCKET NO. 50-272 We have reviewed the Accident Sequence Precursor (ASP) Analysis relating to the April 7, 1994 reactor trip and safety injection at Salem Unit 1. While the Event Description and Additional Event Related Information sections of the ASP are accurate, we believe that the assumed value* for human error associated with realigning the auxiliary feedwater (AFW) pump suction source from the auxiliary feedwater storage tank (AFWST) *to an alternate source is overly conservative. A probability of .04 has been assigned to this input whereas the plant specific value for this event has been calculated to be 8.3E-4. We feel that the plant specific value is appropriate considering that multiple alarms and proceduralized actions would have to fail in order for the realignment not to occur. Since the assumed value for human error dominates the conditional core damage probability calculation presented in your analysis, we request that you consider the information provided below as a basis for revising the calculation.

Technical Specifications require the AFWST be maintained at >90%

level. A control console alarm occurs at 94% level (205,000 gallons) to indicate that the Technical Specification Limit is being approached. Additional alarms occur at 43.1% level (100,000 gallons) and at 10.3% level (30,000 gallons) to alert the operator to an impending low level condition. Alarm response procedure Sl.OP-AR.ZZ-0012(Q) directs the operator to take appropriate action to initiate refill of the tank or to realign to an alternate source if the AFWST tank has become inoperable.

( 9505020319 6~865~72

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LR-N95064 2

Emergency Operating Procedures (EOP) used during the April 7 event also contain provisions to ensure that the alternate suction alignment is accomplished in a timely manner. Procedures 1-EOP-TRIP-1,2 & 3 all contain Continuous Action Summary (CAS) statements directing the realignment of the AFW pump suction to an alternate source if AFWST level decreases below 14%. The CAS's are monitored by the operator and the Shift Technical Advisor throughout an event and appropriate actions taken when directed.

The above referenced proc~dures are provided as Attachment 1, and are submitted in accordance with the guidelines provided in your request for comments. If there are any questions regarding the information contained herein, please feel free to contact us.

Sincerely, Attachment 95-4933

..

t Docdment Control Desk 3 LR-N95064 c Mr. T. T. Martin, Administrator - Region I U. s. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mr. L. Olshan, Licensing Project Manager - Salem

u. s. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 14E21 Rockville, MD 20852 Mr. c. Marschall (S09)

USNRC Senior Resident Inspector Mr. K. Tosch, Manager, IV NJ Department of Environmental Protection Division of Environmental Quality Bureau of Nuclear Engineering CN 415 Trenton, NJ 08625 L

• ATTACHMENT 1 The following procedures are provided for reference purposes; S1.0P-AR.ZZ-0012(Q) Rev. 6 (pages 78-80) 1-EOP-TRIP-1 Rev. 11 1-EOP-TRIP-2 Rev. 12 1-EOP-TRIP-3 Rev. 10

e S 1.0P-AR.ZZ-0012(Q)

SYSTEM AUXILIARY FEED SYSTEM Aux Feedwater Storage Tank AFWST

--

-- --

-- - -- LEVEL

-- --

-- --

-

-

--

APPROACIIlNG

-- --

-- --

-- -- ,_

TECH SPEC BEZEL Alarms & Display DEVICES: lLD-3349 SETPOINT: 94% (205,000 gals)

1.0 CAUSE(S)

1.1 Level in AFWST approaching Technical Specification minimum 2.0 AUTOMATIC ACTIONS:

2.1 None 3.0 OPERATOR ACTIONS:

3.1 MONITOR AFWST level on Console indications.

3.2 OPEN 1DR6, AFW TANK MAKEUP VALVE, as necessary to maintain level

> 90% (T/S minimum) and CONTINUOUSLY MONITOR AFWST level to preclude overflow condition.

3.3 ATTEMPT to detennine cause of level decrease.

A. IF cause cannot be detennined, THEN PERFORM following:

1. SEND an Operator to locate any leakage.

2. INITIATE Work Request to detennine and correct cause of low level.

Page 1of1 4-12

References:

Dwg. 248884, 205236, 611444 Salem 1 Page 78 of 127 Rev. 6

S 1.0P-AR.ZZ-0012(Q)

SYSTEM AUXIUARY FEED SYSTEM Aux Feedwater Storage Tank 11111111m~1 AFWST CH C (A)

LEVEL LO BEZEL Alarms & Display Channel C Channel A DEVICES: lLD-2701 lLD-2955 SETPOINT: 43.1 % (100,000 gals)

1.0 CAUSE(S)

1.1 I.ow level in AFWST 2.0 AtITOMATIC ACTIONS:

2.1 None 3.0 OPERATOR ACTIONS:

3.1 MONITOR AFWST level on Console indications.

3.2 OPEN 1DR6, AFW TANK MAKEUP VALVE, as necessary to maintain level

> 90% (TIS minimum) and CONTINUOUSLY MONITOR AFWST level to preclude overflow condition.

3. 3 IE level cannot be restored, THEN INITIATE efforts to transfer suction of affected pump(s) to an alternate source of water IAW Sl.OP-SO.AF-OOOl(Q), Auxiliary Feedwater System Operation.

3.4 ATIEMPT to detennine cause of level decrease.

A. IF cause cannot be detennioed, THEN PERFORM following:

1. SEND an Operator to locate any leakage.

2. INITIATE Work Request to determine and correct cause of low level.

Page 1of1 4-12

References:

Dwg. 203313, 248884, 205236, 611441, 611443 Salem 1 Page 79of127 Rev. 6

S 1.0P-AR.ZZ-0012(Q)

SYSIEM AUXIUARY FEED SYSTEM Aux Feedwater Storage Tanlc AFWST CH C (A) 11111111mm LEVEL LO-W 1

BEZEL Alanns & Display Channel C Channel A DEVICES: lLD-2671 ILD-3601 SETPOINT: 10.3 % (30,000 gals)

1.0 CAUSE(S)

1.1 Low-Low level in AFWST 2.0 AUTOMATIC ACTIONS:

2.1 None 3.0 OPERATOR ACTIONS:

3.1 MONITOR AFWST level on Console indications.

3.2 TRANSFER. suction of any running AFW pumps to an alternate source of water IAW Sl.OP-SO.AF-OOOl(Q), Auxiliary Feedwater System Operation.

3.3 OPEN 1DR6, AFW TANK MAKEUP VALVE, as necessary to maintain level

> 90% (f/S minimum) and CONTINUOUSLY MONITOR AFWST level to preclude overflow condition.

3.4 ATTEMPT to determine cause of level decrease.

A. D: cause cannot be detennined, THEN:

1. SEND an Operator to locate any leakage.

2. INITIATE Work Request to determine and correct cause of low level.

Page 1 of 1 4-12

References:

Dwg. 203313, 248884, 205236, 611442, 611445 Salem 1 Page 80 of 127 Rev. 6