Information Notice 1990-64, Potential for Common-Mode Failure of High Pressure Safety Injection Pumps or Release of Reactor Coolant Outside Containment During a Loss-Of-Coolant Accident

Potential for Common-Mode Failure of High Pressure Safety Injection Pumps or Release of Reactor Coolant Outside Containment During a Loss-Of-Coolant Accident

ML031130251
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	10/04/1990
From:	Rossi C Office of Nuclear Reactor Regulation
To:
References
IN-90-064, NUDOCS 9009280049
Download: ML031130251 (10)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 October 4, 1990

POTENTIAL FOR COMMON-MODE FAILURE OF HIGH

NRC INFORMATION NOTICE NO. 90-64:

PRESSURE SAFETY INJECTION PUMPS OR RELEASE

OF REACTOR COOLANT OUTSIDEE CONTAINMENT DURING

A LOSS-OF-COOLANT ACCIDENI

Addressees

permits for pressurized-water

All holders of operating licenses or construction

reactors.

Purpose

addressees to the potential

This information notice is being provided to alert injection pumps (charging

for the common-mode failure of the high-head safety coolant outside of contain- pumps) due to gas binding or the release of reactordepending upon the manner in

ment during a loss of coolant accident (LOCA), installed. It is expected that

which the vent line isolation valves have been to their facilities

recipients will review the information for applicability

similar problems. However, and consider actions, as appropriate, to avoid do not constitute NRC re- suggestions contained in this information notice response is required.

quirements; therefore, no specific action or written

Description:

in preparation for refueling

On July 9, 1990, with the plant in cold shutdown

Volume Control Tank (VCT) discharge

operations, the Haddam Neck licensee had the Volume Control System (CYCS).

and vent flow paths isolated in the Chemical and

water storage tank (RWST),

The charging pumps were aligned to the refueling system in operation. The

with a train of the residual heat removal (RHR)

water was draining from the

Haddam Neck licensee subsequently discovered that (see Figure 1). The 3/4-inch

VCT through the high-point vent isolation valves isolation valves, provides for

vent line, containing two ASCO solenoid-operated of the charging pump

continuous venting of hydrogen from the high points operations. Further

suction piping to the VCT, during normal CYCS letdown valves would not isolate

investigation by the licensee revealed that the ASCO unseats with a differen- in the reverse flow direction because the valve discThe licensee indicated, as

tial pressure across the valve seat of 15-30 psid. solenoid- a result of discussions held with ASCO, that no ASCO-manufactured

in the reverse flow direction.

operated valves were designed to provide isolation

(SIAS) causes the normal

Initiation of a safety injection actuation signal closure of-the VCT dis- discharge path from the VCT to isolate by automatic pumps is then switched

charge isolation valves. The suction of the charging

( 9009280049

IN 90-64, October 4, 1990 from the VCT to the RWST. The ASCO vent line isolation valves

matically upon closure of the VCT discharge isolation valves andare shut auto- manually

de-energized. With the valves in the closed position, a differential pressure

in the reverse flow direction could allow gases in the VCT to pass

high-point vent line and. cause gas binding of the pumps. Haddam through the

to this concern by adding two check valves as shown in Figure 1. Neck responded

Discussion:

At Haddam Neck, the licensee identified a possible common-mode failure

high-point vent isolation valves in the suction vent line that connects to both

charging pumps to the YCT. The common mode failure occurs if there the

is leakage

flow through both valves after they have been shut. From their discussions

with the valve manufacturer (ASCO), the licensee learned that these

designed to provide isolation in one flow direction only. The ASCO valves are

identified as solenoid-operated, two-way, 1/2 inch isolation valves valves are

maximum pressure rating of 400 psig and are commerical grade. The with a

model

numbers of the valves are 6109R and L8211D89. The installed configuration

the ASCO valves at Haddam Neck was such that failure of these valves of

during a LOCA (i.e., during the ECCS injection phase) could drain to isolate

and allow hydrogen gas in the VCT (and any gas that had accumulateddown the VCT

line) to be transported to the suction of the charging pumps by way in the vent

high-point vent charging pump suction line. of the

A second scenario, was identified by the licensee involving the

recirculation

phase of a small-break LOCA, when the RHR pumps supply reactor coolant

sump to the suction header of the charging pumps. If the ASCO valves from the

installed in the reverse direction (i.e., to isolate venting from are

the suction of the charging pumps), then the discharge pressure the VCT to

from the RHR

pumps would be enough to increase pressure in the vent line to the

valves so as to lift the valve discs off of their seats and pressurizeASCO isolation

in excess of the 75 psig VCT relief setpoint. This would allow the VCT

reactor coolant outside containment. a release of

In addition, if the two ASCO vent line valves are installed in opposite

a single failure of a vent line isolation valve could lead to either directions, or a release of reactor coolant outside of containment. Licensees gas binding

with similar

vent lines and ECCS pump arrangements may wish to review the above

for applicability to their plants. information

The effectiveness of the Haddam Neck high point vent configuration

Figure 1) was not evaluated in conjunction with the development (as shown in

of this informa- tion notice. It is important that any plant modifications made

hydrogen buildup concerns do not introduce other ways for gas to to alleviate

into the charging pump suction or other safety concerns. be ingested

IN 90-64, October 4, 1990 Safety

Information notice 88-23, "Potential for Gas Binding of High Pressure 1 Injection Pumps During A Loss-Of-Coolant Accident" (including Supplements

of high

and 2) also describes situations that could result in gas binding

pressure safety injection pumps.

notice.

No specific action or written response is required by this information

If you have any questions about this matter, please contact the technical

NRC

contact listed below or the Regional Administrator of the appropriate

regional office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

John Thompson, NRR

(301) 492-1171 Attachments: 1. Figure 1, Haddam Neck High Point Vent Line

2. List of Recently Issued NRC Information Notices

v Detachment 1 IN 90-64 October 4, 1990 Haddam Neck High Point Vent Line

ASCO 1/2" solenoid valves

installed check valves

To

WIST

Charging Pump

Is I

Charging Pump From RHR

PuMpO

Attachment 2 IN 90-64 October 4, 1990 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

90-63 Management Attention to the 10/3/90 All fuel cycle

Establishment and Main- licensees possess- tenance of A Nuclear ing more than

Criticality Safety Program critical mass

quantities of

special nuclear

material.

90-62 Requirements for Import 9/25/90 All irradiated

and Distribution of gemstone importers

Neutron-Irradiated Gems and distributors, and all non-power

licensees.

90-61 Potential for Residual 9/20/90 All holders of

Heat Removal Pump OLs or CPs for

Pump Damage Caused By nuclear power

Parallel Pump Interaction reactors.

90-60 Availability of Failure 9/20/90 All holders of

Data In the Government- OLs or CPs for

Industry Data Exchange nuclear power

Program reactors.

90-59 Errors In the Use of 9/17/90 All medical

Radioactive Iodine-131 licensees.

90-58 Improper Handling of 9/11/90 All NRC medical

Ophthalmic Strontium-90 licensees.

Beta Radiation Applicators

90-57 Substandard, Refurbished 9/5/90 All holders of OLs

Potter & Brumfield Relays or CPs for nuclear

Misrepresented As New power reactors.

90-56 Inadvertent Shipment of A 9/4/90 All U.S. Nuclear

Radioactive Source In A Regulatory Com- Container Thought To Be mission (NRC)

Empty licensees.

OL = Operating License

CP = Construction Permit

IN 90-64, October 4, 1990 Information notice 88-23, "Potential for Gas Binding of High Pressure Safety

Injection Pumps During A Loss-Of-Coolant Accident" (including Supplements 1 and 2) also describes situations that could result in gas binding of high

pressure safety injection pumps.

No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the technical

contact listed below or the Regional Administrator of the appropriate NRC

regional office.

.kLCtharles E. Rossi, Directo

( Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

John Thompson, NRR

(301) 492-1171 Attachments: 1. Figure 1, Haddam Neck High Point Vent Line

2. List of Recently Issued NRC Information Notices

• See Previous Concurrence 9 4 1 OFC :OEAB:DOEA :AC:OEAB:DO A:RPB:ADM :D:DST:NRR :C:OGCB:DOEA :D:DOE:R

X

NAME :*JWThompson :*DCFischer  :*Tech Ed  :*ACThandani :*CHBerlinger:ERossi

DATE :08/28/90 :08/28/90 :08/28/90 :09/04/90 :09/17/90 :09agyggo  :

OFFICIAL RECORD COPY

Document Name: INFORfTO'-- //J qo90-c,

rN 90-xx, ,

vU ve r-X, 1990

,Pge 3 of 3 and 2) also describes situations that could result i gas binding of high

pressure safety injection pumps.

No specific action or written response is requi d by this information notice.

If you have any questions about this matter, ease contact the technical

contact listed below or the Regional Adminis ator of the appropriate NRC

regional office.

harles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

John Thomp on, NRR

(301) 492 171 Attachments: 1. Figure 1 Haddam Neck High Point Vent Line

2. List of Recently Issued NRC Information Notices

• See Previous Concurrence

OFC :OEAB:DOEA :AC:OEAB:DOEA:RPB:ADM :D:DST:NRR :C:OGCB:DOEA :D:DOEA:NRR  :

NAME :*JWThompson :*DCFischer  :*Tech Ed  :*ACThandani :*CHBerlinger:ERossi

---

 : ------------  :----------_ _:_----------- :____________-___

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_--_---____--_____---

DATE :08/28/90 :08/28/90 :08/28/90 :09/04/90 :09/17/90 :09/ /90  :

OFFICIAL RECORD COPY

Document Name: INFORNOT

IN 88-23, SUPPLEMENT 3 September XX, 1990 No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the technical

contact listed below or the Regional Administrator of the appropriate NRC

regional office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

John Thompson, NRR

(301) 492-1171 Attachments: 1. Figure 1, Haddam Neck High Point Vent Line

2. List of Recently Issued NRC Information Notices

• See Previous Concurrence

OFC :OEAB:OOEA :AC:OEAB:DOEA:RPB:ADM D:IDST:NRR :12:0fifFp9::D:DOEA:NRR

• . . . .

NAME :*JWThompson :*DCFischer  :*Tech Ed  :*ACThandani :CHBerlinger :ERossi

__ * ------------ _ __________ _ ____.____ ______ _ __ ___ _ ______-__ _________--______

DATE :08/28/90 :08/28/90 :08/28/90 :09/04/90 :09/17/90 :09/ /90

OFFICIAL RECORD COPY

Document Name: INFORNOT

IN 88-23, SUPPLEMENT 3 August XX, 1990 valves are de-energized and shut upon closure of the VCT discharge isolation

valves. With the valves in the closed position, a differential pressure buildup

in the reverse flow direction could allow gases in the VCT to be siphoned through

the high-point vent line and gas bound the pumps. Haddam Neck responded to this

concern by adding two check valves as shown in Figure 1.

Discussion:

At Haddam Neck the licensee identified a possible common-mode failure to both

high-point vent isolation valves in the suction vent line that connects the

charging pump to the VCT. The common mode failure occurs if there is flow

through both valves after they have been shut. From their discussions with the

valve manufacturer (ASCO), the licensee learned that these valves are designed

to provide isolation in one flow direction only. The installed configuration of

the ASCO valves at Haddam Neck was such that failure of these valves to isolate

during a LOCA could allow hydrogen gas in the YCT (and any gas that had accumulated

in the vent line) to be transported to the suction of the charging pumps by way

of the high-point vent charging pump suction line. If the ASCO valves are

installed in the reverse direction (i.e., to isolate venting from the VCT to the

suction of the charging pumps), then operation of the RHR pumps in a LOCA

scenario could allow enough differential pressure to be exerted against the

valve discs to lift them off of their seats and pressurize the vent line to the

VCT in excess of the 75 psig VCT relief setpoint. This could allow a release

of reactor coolant outside containment. If the vent line valves are installed

in opposite directions, the safety concern is that a single failure could lead

to either gas binding or release of reactor coolant outside of containment.

Licensees with similar vent lines and ECCS pump arrangements may wish to review

the above information for applicability to their plants.

No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the technical

contact listed below or the Regional Administrator of the appropriate NRC

regional office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Rdactor Regulation

John Thompson, NRR

(301) 492-1171 Attachments: 1. Figure 1, Haddam Neck ohnt Vent Line

2. List of Recentl Iss N C Information Notices

1  :  :

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NAME :JTh ischer :Tech  : CThandani :CBerlinger

DATE :08/d90 :O8 90 :08/ M :t/M/90 :08/ /90

OFFICIAL RECORD COPY

Document Name: INFONOTE 8823 SUPP 3