Information Notice 1986-63, Loss of Safety Injection Capability

Loss of Safety Injection Capability

ML031250058
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, 05000000, Zimmer, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant, Skagit, Marble Hill
Issue date:	08/06/1986
From:	Jordan E NRC/IE
To:
References
IN-86-063, NUDOCS 8608010289
Download: ML031250058 (4)

SSINS No.: 6835 IN 86-63 UNITED STATES E

R WIthE D

NUCLEAR REGULATORY COMMISSION ie rt D. Nuear

OFFICE OF INSPECTION AND ENFORCEMENT VIC Pres1e Nuc1ear

WASHINGTON, DC 20555 Ru To:G 1986 August 6, 1986 IE INFORMATION NOTICE NO. 86-63: LOSS OF SAFETY INJECTION CAPABILITY

Addressees

All pressurized water nuclear power reactor facilities holding an operating

license or a construction permit.

Purpose

This notice is to alert recipients to a potentially significant problem per- taining to the loss of safety injection (SI) capability as a result of

common-mode failure of SI pumps from crystallization of boric acid. The NRC

expects that recipients will review this notice for applicability to their

facilities and consider actions, if appropriate, to preclude a similar problem

occurring at their facilities. However, suggestions contained in this notice

do not constitute NRC requirements; therefore, no specific action or written

response is required.

Related Documents:

AEOD Engineering Evaluation Report E606: 'Loss of Safety Injection Capability

at Indian Point Unit 2," May 1986.

NRR Generic Letter 85-16: "High Boron Concentrations," August 23, 1985.

NRC "Report to Congress on Abnormal Occurrences," NUREG-0090, Vol. 8, No. 2, November 1985.

Description of Circumstances

On December 28, 1984, during operations to top off the ECCS accumulators, the

licensee at Indian Point Unit 2 observed discharge pressure to two SI pumps to

drop from 1100 psig and 1500 psig, respectively, to about 700 psig corresponding

to accumulator pressure. These pumps were secured from operation. The third SI

pump could not be manually started. The licensee declared all the safety

injection (SI) pumps inoperable and manually tripped the reactor. The

malfunction of the pumps was apparently caused by boric acid crystallization

blocking pump suction and by possible gas binding of the pumps.

Two parallel, leaky valves in the discharge line of the boron injection tank

(BIT) enabled highly concentrated boric acid to flow through the low pressure

Copies to: Withers, Yundt, Lentsch, Orser, Steele, E. Burton, E. Jordan, A. Holm, LIS,

C. A. Olmstead, S. Hoag, S. Sautter, R. Johnson, TNP:GOV REL F:NRC CHRONO,

TNP GOV REL F:NRC IE Information Notice 86-63 PGE Action - None Required "Completed - BIT Removed

See License Amendment 103"

A- / - '

0

IN 86-63 August 5, 1986 the pumps, which were

discharge line (SI pump suction) and to precipitategasindissolved in the boric

not heat traced. Degassing of the nitrogen cover sources of gas found in the

acid solution is believed to be one of the likely

pumps.

On May 10, 1974, a precursor to this event took placeinoperableat Indian Point 2. In

as a result of

that event, two of the three SI pumps were rendered pumps at that time.

boric acid crystallization. No gas was noted in the

On June 1, 1984, while in cold shutdown, the licensee at San Onofre Unit 1 the plant's Technical Specifi- found the two boric acid flow paths required by by crystallization of boric

cations to be blocked. The blockage was caused the charging pumps. There

acid between the boric acid storage tank (BAST) and and other a boric acid

are two parallel lines, one having a transfer pump were the using highly concen- injection pump. Both were blocked. The operators up to the refueling water

trated boric acid from the BAST to rapidly make and solubility. Viable

storage tank (RWST) but failed to monitor concentration the charging pump suction to

alternate flow paths were established by shifting transfer pump.

the RWST and by using a manual bypass valve for the

Discussion:

These events demonstrate the potential for losing eitheremergency safety injection

boric acid crystalliza- capability by common-mode failure resulting from binding possibility in the

tion or gas binding of the pumps. As to the gas

studied the possible sources

December 1984 event at Indian Point 2, the licensee gas evolution on pump

of gas and concluded that the probable effect of

performance would be minor.

Originally in Westinghouse ( plants, the addition of highly concentrated

reactor coolant system (RCS) following

boric acid solution (20,000 ppm) to the intended to compensate for the

a design-basis main steam line break (MSLB) was

cooling of the RCS.

addition of positive reactivity to the core by the sudden downstream of the SI

In most W plants, the BIT (or equivalent) is located

BIT contents into the RCS,

pumps. Dn an SI signal, the pumps inject the

SI system shutoff pressure. Indian

provided the RCS pressure is less than the the BIT upstream of the SI pumps.

Point Unit 2 is among the few W PWRs that has

Other plants with a source of boric acid similarly located include San Onofre

1, Haddam Neck, Yankee Rowe, Point Beach 1 and 2, Prairie Island 1 and 2, Kewaunee, and Ginna. Of these plants, San Onofre RWST 1, Haddam Neck, and Yankee

for SI. Indian Point 2 Rowe use typically 2,000 ppm boric acid from thePoint Beach 1 and 2, Prairie

uses a 20,000 ppm solution from the BIT, while solution from the BAST for

Island 1 and 2, Kewaunee, and Ginna use a 20,000 ppm

SI.

in some W PWRs have

Recent evaluations of the design-basis MSLB accidentsacid requirements. In some

revealed excessive conservatism regarding boric10 CFR 100 would not be exceeded

cases, it was shown that the requirements ofacid concentration were reduced.

if the BIT were eliminated or if the boric NRR sent Generic

Following the Indian Point 2 event on December 28, 1984,

IN 86-63 August 5, 1986 their

Letter 85-16 to all licensees of W plants to encourage them to reevaluate

Indian Point 2, MSLB analysis and the need for the BIT. So far, in addition to

at least the following plants have received NRR approval for removal of their

.BIT and/or for modifying technical specification requirements that would allow

operation with reduced boric acid concentrations:

Turkey Point 3 and 4 Harris 1 Surry 1 and 2 Beaver Valley 1 South Texas

McGuire 1 (McGuire 2 was licensed without a BIT)

Catawba 1 and 2 Callaway

Farley 1 and 2 Trojan

For those plants that are still required to provide high boric acid concentra- SI

tions for SI, plant-specific procedures normally provide for flushinginthe the

system after every SI actuation to prevent boric acid precipitation

piping and for periodic sampling of the SI system.

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

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

Administrator of the appropriate regional office or this office.

Director

Divis fn of Emergency Preparedness

and Engineering Response

Office of Inspection and Enforcement

Technical Contacts: Vern Hodge, IE

301-492-7275 Raji Tripathi, AEOD

301-492-4435 Attachment: List of Recently Issued IE Information Notices

• 1 Attachment 1 IN 86-63 August 5, 1986 LIST OF RECENTLY ISSUED

IE INFORMATION NOTICES

Information Date of

Notice No. Subject Issue Issued to

86-62 Potential Problems In West- 7/31/86 All power reactor

inghouse Molded Case Circuit facilities holding

Breakers Equipped With A an OL or CP

Shunt Trip

86-61 Failure Of Auxiliary Feed- 7/28/86 All power reactor

water Manual Isolated Valve facilities holding

a CP

86-60 Unanalyzed Post-LOCA Release 7/28/86 All power reactor

Paths facilities holding

an OL or CP

86-31 Unauthorized Transfer And 7/14/86 All NRC general

K~ Sup. 1 Loss Of Control Of Industrial licensees that possess

Nuclear Gauges and use industrial

nuclear gauges

86-59 Increased Monitoring Of 7/14/86 All NRC licensees

Certain Patients With authorized to use

Implanted Coratomic, Inc. nuclear-powered

Model C-100 and C-101 cardiac pacemakers

Nuclear-Powered Cardiac

Pacemakers

86-58 Dropped Fuel Assembly 7/11/86 All power reactor

facilities holding

an OL or CP

86-57 Operating Problems With 7/11/86 All power reactor

Solenoid Operated Valves At facilities holding

Nuclear Power Plants an OL or CP

86-56 Reliability Of Main Steam 7/10/86 All PWR facilities

Safety Valves holding an OL or CP

86-55 Delayed Access To Safety- 7/10/86 All power reactor

Related Areas And Equipment facilities holding

During Plant Emergencies an OL or CP

OL = Operating License

CP = Construction Permit