05000272/LER-1987-017, :on 871113,six Leakage Pathways from Unit 1 Auxiliary Feedwater Pump Compartment 13 & One Pathway from Unit 2 Identified.Caused by Control of Design Requirements. Leakage Paths Sealed & Field Directive Will Be Issued

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:on 871113,six Leakage Pathways from Unit 1 Auxiliary Feedwater Pump Compartment 13 & One Pathway from Unit 2 Identified.Caused by Control of Design Requirements. Leakage Paths Sealed & Field Directive Will Be Issued
ML18093A625
Person / Time
Site: Salem 
Issue date: 01/26/1988
From: Pollack M
Public Service Enterprise Group
To:
Shared Package
ML18093A627 List:
References
LER-87-017, LER-87-17, NUDOCS 8802090450
Download: ML18093A625 (4)
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LER-1987-017, on 871113,six Leakage Pathways from Unit 1 Auxiliary Feedwater Pump Compartment 13 & One Pathway from Unit 2 Identified.Caused by Control of Design Requirements. Leakage Paths Sealed & Field Directive Will Be Issued
Event date:
Report date:
2721987017R00 - NRC Website
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text

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iillC forMJll IM:IJ LICENSEE EVENT REPORT (LEA)

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- OVID OMI NO. 3110-41CM EX,.llES: 1131
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I.&, _.,.1mno1y,,_ r1,.,,,..,,... ry,.,..,,mn llnmJ 1111 On 11/13/87 an NRC inspector identified leakage paths from the No. 13 Auxiliary Feedwater (AFW) Turbine.Driven Pump compartment {BAI.

Subsequent investigation revealed six (6) unsealed openings from the Unit 1 pump and one unsealed opening from the Unit 2 pump.

The compartment encloses the steam feed piping to the AFW Turbine Driven Pump such that a postulated pipe break would not damage adjacent vital electrical equipment located outside the compartment.

The root cause of the Steam Driven AFW Pump compartment deficiencies has been attributed to control of design requirements.

The leakage paths identified on the Salem Units 1 & 2 Steam Driven AFW Pump enclosures have been sealed.

A review of other protective pipe rupture enclosures, to verify their integrity has been maintained, is continuing.

To ensure that adequate attention is given to the maintenance of these structures in the future, the Program Analysis.c Group (PAG) will issue a Field Directive identifying the areas that-:

are designed to accommodate the effects of a pipe rupture.

Based on the Field Directive, administrative controls to maintain protective structures in a condition that meets their design requirements will be reviewed and changes made as necessary.

8802090450 880126 PDR ADOCK 05000272 s

PDR I

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem-Generating Station Unit 1 DOCKET NUMBER 5000272

PLANT AND SYSTEM IDENTIFICATION

Westinghouse Pressurized Water Reactor LER NUMBER 87-017-02 PAGE 2 of 4 Energy Industry Identification System (EIIS) codes are identified in the text as f xxl IDENTIFICATION OF OCCURRENCE:

Discovered Leakage Paths From 13(23) Aux Feedwater Pump Compartment -

Control of Design Requirements Event Date:

11/13/87 Report Date: 01/26/88 This report was initiated by Incident Report No.87-449.

CONDITIONS PRIOR TO OCCURRENCE:

Mode 6 Reactor Power 0% - Unit Load 0 MWe DESCRIPTION OF OCCURRENCE:

On 11/13/87 an NRC inspector identified leakage paths from the No. 13 Auxiliary Feedwater (AFW) Turbine Driven Pump compartment [BA}.

Subsequent investigation revealed six (6) leakage pathways from the Unit 1 pump compartment. and one pa.thway from the Unit 2 pump compartment.

The compartment encloses the steam feed piping to the AFW Turbine Driven Pump such that a postulated pipe break would not damage adjacent vital electrical equipment located outside the compartment.

The Unit 1 pump compartment pathways consist of four (4) pipe penetrations where excessive annulus areas exist between the pipe and the compartment wall, one (1) hole cut to accommodate a protruding bolt~ and one (1) small hole cut through the steel compartment wall for no known reason.

The Unit 2 pump compartment pathway is a pipe

  • penetration with an excessive annulus area between the pipe*and wall.
- APPARENT CAUSE OF OCCURRENCE:

The root cause of the Steam Driven AFW Pump compartment deficiencies is associated with control of design requirements.

"Notes" on the AFW Pump enclosure controlled drawings (bot~ Units) state that the compartment structure is designed for an internal pressure of 50 pounds per square foot (psf).

Also, the drawing "Notes" indicate that gaps and cracks in the structure should be minimized during erection and plugged as required to ensure a reasonable degree of watertightness.

It cannot be conclusively determined what activities took place that resulted in these leakage paths whether from the original design configuration or as the result of design modifications.

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem*Generating Station Unit 1 DOCKET NUMBER 5000272 LER NUMBER 87-017-02 PAGE 3 of 4*

The Salem Unit 1 AFW Pump compartment was analyzed due to the greater open area than the Unit 2 AFW Pump enclosure.

The total unsealed area for the Unit 1 and Unit 2 compartments was approximately 20 square inches and four square inches, respectively.

The AFW Pump enclosure is designed to contain the steam release from a postulated steam pipe rupture such that adjacent vital electrical equipment is not damaged.

In the* event of a postulated pump steam supply line rupture (high energy line break} within the compartment, the compartment temperature and pressure would rise.

At 0. 33 psi, exhaust dampers will op*en to vent steam into the adjacent Auxiliary Building pipe alley.

The total effective free flow area provided by the dampers is 1265 in2

  • The unsealed openings represented an increase in the available exhaust area of 1.6%.

The total steam discharge rate from a *postulated break is 11.0 lb.ls of steam at an initial pressure.of 1020 psia, 547°F.

The amount of steam discharged.to the adjacent area of the enclose through the unsealed openings is 1.6% of 11.0 lb.ls which equals 0.17 lb./s.

This will be an adiabatic expansion into the area at slightly less than atmosperic pressure.

This process will reduce the temperature of t_he exiting steam to 300° F.

The specific volume of steam.at these conditions (14.7 psia and 300°F) and a mass flow rate of O.i7 lb.ls will result in 300 cfm of steam exhausted into the area.

Steam with a molecular weight of 18 will rise to the. ceiling.

The ceiling area has ventilation exhaust ducts with an exhaust capacity of 500 cfm.

Therefore, the steam will be exhausted, via the Auxiliary Building Ventilation System, and will* not accumulate in the adjacent area.

The operability of equipment adjacent to the enclosure will not be compromised by the steam release.

The adjacent area contains the 11(21) and 12(22) Motor Driven AFW Pumps,. various AFW valves, Main Steam System valves (Unit 2 only), the 1(2)A and 1(2}C West 230 V Vital Motor Control Centers (MCCs); and various electrical panels, including the Alternate Shutdown Panel (Panel 213).

This equipment will remain operable during the postulated steam release.

The 230 V MCCs provide power and control to a variety of Emergency Core Cooling System (ECCS) valves, including one Residual Heat Removal (RHR) Pump Minimum Flow Valve (11RH29) (BPI, the Safety Injection Pump Minimum Flow Valves (SJ67 & 68), an RHR Loop Crosstie Valve (11RH19),

one suction valve from the Reactor Water Storage Tank to the Charging Pumps (lSJl),_ a Containment Sump Isolation Valve (11SJ44), and Component Cooling Water discharge valve from the RHR Heat Exchanger (11CC16).

Since an ECCS actuation is not expected to occur as a result of the postulated break, these ECCS valves would not be required to operate.

Also, since a fire is not postulated coincident with a pipe break, the Alternate Shutdown Panel would not be required.

However, in the event of a break in the steam supply line to the AFW Turbine Driven Pump, the Motor Driven AFW Pumps and valves would be required to operate

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station u*n.i t 1

DOCKET NUMBER 5000272 ANALYS.LS OF OCCURRENCE~

(cont'd)

-~~~~~

LER NUMBER 87-017-02 PAGE 4 of 4 during normai plant cooldown to remove heat from the core until the RHR System could be placed in operation.

In summary, the equipment adjacent to the Steam Driven AFW Pump are necessary to normal plant operation as well as mitigation of design base accidents.

They are required to be protected against the dynamic effects of a postulated pipe rupture.

As discussed above, the operability of equipment adjacent to the Steam Driven AFW Pump compartment would not have been effected by a postulated steam supply line break.

_CORREC'IIVE _ACTION:

The leakage paths identified on the Salem Units 1 & 2 Steam Driven AFW Pump enclosures have been sealed.

A review of other protective pipe rupture enclosures, to verify their integrity has been maintained, is continuing.

To ensure that adequate attention is given to the maintenance of these structures in the future, the Program Analysis Group (PAG) will issue a Field Directive (by February 16, 1988) identifying the areas that are.designed to accommodate the effects of a pipe rupture.

Based on the Field Directive, administrative controls to maintain protective structures in a condition that meets their design requirements will be reviewed and changes made as necessary.

i1Jl-':pc SORC Mtg.88-009

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Salerr, Operation!':

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