Information Notice 1989-32, Surveillance Testing of Low-Temperature Overpressure-Protection Systems

Surveillance Testing of Low-Temperature Overpressure-Protection Systems

ML031180747
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
Issue date:	03/23/1989
From:	Rossi C Office of Nuclear Reactor Regulation
To:
References
IN-89-032, NUDOCS 8903170419
Download: ML031180747 (7)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 March 23, 1989 NRC INFORMATION NOTICE NO. 89-32: SURVEILLANCE TESTING OF LOW-TEMPERATURE

OVERPRESSURE-PROTECTION SYSTEMS

Addressees

All holders of operating licenses or construction permits for pressurized-water

reactors (PWRs).  :

Purpose

This information notice is being provided to alert addressees to potential

operability problems due to lack of inservice testing of power-operated relief

valves (PORVs) in their low-temperature overpressure-protection (LTOP) mode.

It is expected that recipients will review the information for applicability to

their facilities and consider actions, as appropriate, to avoid similar prob- lems. However, suggestions contained in this information notice do not consti- tute NRC requirements; therefore, no specific action or written response is

required.

Description of Circumstances

Beaver Valley: During an inspection (Inspection Report No. 50-334, 412/86-20),

NRC inspectors noted that technical specifications (TS) require that over- pressure protection be provided by two PORYs with a nominal trip setpoint of

less than or equal to 350 psig whenever the temperature of a non-isolated

reactor coolant system (RCS) cold leg is less than or equal to 2750 F. The TS

surveillance requirement only addresses stroking the operable PORY each time

the plant enters Mode 5 (cold shutdown) unless that PORY has been tested within

the preceding three months.

The licensee analyzed two cases for an overpressure accident scenario: (1) a

mass input case and (2) a heat input case. The most restrictive PORY opening

time was identified as the mass input accident which would require a valve to

open within 2.5 seconds. An NRC safety evaluation report (SER) dated April 4,

1983 found this analysis to be acceptable. A review of the licensee's mainte- nance surveillance procedure indicated that the nominal trip setpoint of less

than or equal to 350 psig was addressed, but the stroke time was not.

Plant TS and procedures had not implemented PORV stroke times as assumed in the

analysis. The licensee performed an evaluation using data from the station's

ASME Valve Stroke Log, when compared to SER stroke time assumptions. The licensee

(8903170419 Zt )

IN 89-32 March 23, 1989 concluded that the resulting maximum RCS pressure would still

have been within

specified limits. However, the licensee initiated several procedural

ments to address PORY stroke testing. improve- Turkey Point: The staff inspected the licensee's overpressure

system (MS) (Inspection Report Nos. 50-250, 251/88-14 and 88-26). mitigation

electronics operability and setpoints are verified before being The PORY

low-pressure operations. The inspectors reviewed the stroke aligned for

3 and 4 PORVs from May 1984 through May 1988. These tests were times for the Unit

accordance with the licensee's inservice test (IST) program. performed in

ment for each PORV is to fully stroke within 15 seconds. The The IST require- reviewed ranged from less than 2.0 seconds up to 6.41 seconds. stroke times

These stroke

times are well below the 15-second IST criterion. However, in

porting license amendments, a relief valve opening time of 2.0 analyses sup- assumed in calculating the setpoint overshoot for the mass input seconds was

heat input case assumed a relief valve opening time of 3.0 seconds. case. The

on average, were not meeting the design-basis stroke time. The PORVs, The licensee requested relief from the TS requirement in order

the eventual refueling outage that would place one of the units to prepare for

operating regime of the OMS. The request extended to the next within the

for each of the units in order to allow the licensee time to refueling outage

resolve this

issue. The licensee requested that Westinghouse perform an

analysis

the magnitude of the overshoot considering the-followingtransients to determine

1) the _

start of-an~--dT- ieact6rc6olaint pump with the secondary water

temperature

of the steam generator less than or equal to 500 F above the

temperature; 2) the start of a high pressure safety injectionRCS cold-leg

injection into a water-solid RCS and 3) the inadvertent start pump and Its

pumps with a loss of letdown. The safety evaluation demonstrated of two charging

PORY opening stroke time up to 3.45, the OMS could mitigate the that with a

most limiting

transient (spurious start of a ST pump). The licensee has completed

change for Unit 4 and is planning to implement the design change a design

during the next refueling outage. This design change will ensure on Unit 3 PORVs will open in time to prevent exceeding the 10 CFR 50, that the

The surveillance procedures supporting the TS were changed soAppendix G limits.

stroke time testing will use an acceptance criterion that is that future

consistent

with the design basis.

Shearon Harris: NRC inspectors assessing operational performance

Report No. 50-400/88-34) noted a discrepancy concerning the testing(Inspection

pressurizer PORYs. An IST procedure specified that the PORYs of the

tested from the open to closed position with a maximum stroke were to be stroke

time of 2.0

seconds. The licensee tested the PORVs in accordance with an

lance test for pressurizer PORY operability. Although no safety 18-month surveil- credit was taken for the PORYs at power operation, they were analysis

required to

provide overpressure protection (by opening on demand) during

low-temperature

operation. Shearon Harris utilizes two of the three PORYs for

the LTOP system.

IN 89-32 March 23, 1989 The design basis of the licensee's LTOP is to protect the RCS from overpressure

when the transient is limited to: (1) start of an idle reactor coolant pump

with secondary-side water temperature less than 50F above RCS cold-leg temper- ature or (2) start of a charging safety injection pump and its injection into a

water-solid RCS. The PORY setpoints were calculated to maintain the RCS below

the maximum allowable system pressure given in 10 CFR 50 Appendix G. The

setpoint calculations assumed a valve opening time of 2.0 seconds in determin- ing the possible overshoot. The inspectors noted that if the actual valve

opening times were greater than 2.0 seconds, then the pressure overshoot could

be greater than originally calculated. A significant increase in valve opening

time could result in the 10 CFR 50 Appendix G limits being exceeded during a

design-basis transient.

The PORYs were stroked in the open direction so that the licensee could perform

the time-to-close test. However, the surveillance procedure did not require

that the time to open be determined, and this was not done.

Discussion:

The basic issue in these three cases is that the licensee's inservice testing

of its low-temperature overpressure-protection (LTOP) systems may be inade- quate. Stroke time requirements used in analyses of the licensee's LTOP

systems were not being transferred into IST requirements and eventually into

surveillance test procedures. The ASME Code,Section XI, paragraph IWV-3400,

requires valves to be exercised to the position required to fulfill their

function. Therefore, not testing the LTOP PORYs in the open direction is a

concern.

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

If you have any questions about this matter, please contact one of the tech- nical contacts 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

Technical Contacts: Milton Shymlock, RII

(404) 331-5542 Thomas McElhinney, Res. Insp., Turkey Pt.

(305) 245-7669 Attachment: List of Recently Issued NRC Information Notices

Attachaent

IN 89-32 I

March 23. 1989 Pap 1 of I

LIST OFRECENTLY ISSUED

NRCINFORMATION NOTICES

information Date of

Notice No. Subject Issuance Issued to

89-31 Swulling and Cracking 3/22/89 All holders of OLs

of Hafni1m Control Rods or CPs for PVRI with

Hafniua control rods.

89-30 High Tperature 3/15S89 All holders of CLs

Enviroiments at or CPs for nuclur

Nuclear Power Plants power re ctors.

89-2S Potential Failure of 3/15/89 All holders of OMs

ASEA Brown Boveri or CPs for nuclear

Circuit Breakers powr ructors

During Seismic Event

8928 Weight and Center of 3/14189 All holders of OLs

Gravity Discrepancies or CPs for nuclear

for Copes-Vulcan Power re ctors.

Air-Operated Valves

89-27 Limitations on the Use 3/8/89 All holders of Ots

of Waste Forms and High or CPs for nuclear

Integrity Containers for power reactors, fuel

the Disposal of Low-Level cycle licenses and

Radioactive Waste certaim by-product

materials licenses.

89-26 Instrument Air Supply to 3/7/89 All holders of 04.

Safety-Related Equipment or CPs for nuclear

power reactors.

89-25 Unauthorized Transfer of 3/7/89 All U.S. NRCsource.

O1ership or Control of byproduct, and special

Licensed Activities nuclear material

licensees.

89-24 Nuclear Criticality Safety 3/6/89 All fuel cycle

licensees and other

licensees possessing.

mo than critical

mass quantities of

special nuclear

material.

O.

• Operating License

CP* Construction Permit

UNITED STATES FIRST CLAS MAII

NUCLEAR REGULATORY COMMISSION POSTAGE & FEES PAID

WASHINGTON, D.C. 20555 USNRC

PERMIT No. 0-9 OFFICIAL BUSINESS

PENALTY FOR PRIVATE USE, $300

IN 89-32 March 23, 1989 The design basis of the licensee's LTOP is to protect the RCS from overpressure

when the transient is limited to: (1) start of an idle reactor coolant pump

with secondary-side water temperature less than 500 F above RCS cold-leg temper- ature or (2) start of a charging safety injection pump and its injection into a

water-solid RCS. The PORY setpoints were calculated to maintain the RCS below

the maximum allowable system pressure given in 10 CFR 50 Appendix G. The

setpoint calculations assumed a valve opening time of 2.0 seconds in determin- ing the possible overshoot. The inspectors noted that if the actual valve

opening times were greater than 2.0 seconds, then the pressure overshoot could

be greater than originally calculated. A significant increase in valve opening

time could result in the 10 CFR 50 Appendix G limits being exceeded during a

design-basis transient.

The PORVs were stroked in the open direction so that the licensee could perform

the time-to-close test. However, the surveillance procedure did not require

that the time to open be determined, and this was not done.

Discussion:

The basic issue in these three cases is that the licensee's inservice testing

of its low-temperature overpressure-protection (LTOP) systems may be inade- quate. Stroke time requirements used in analyses of the licensee's LTOP

systems were not being transferred into IST requirements and eventually into

surveillance test procedures. The ASME Code,Section XI, paragraph IVIV-3400,

requires valves to be exercised to the position required to fulfill their

function. Therefore, not testing the LTOP PORVs in the open direction is a

concern.

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

If you have any questions about this matter, please contact one of the tech- nical contacts 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

Technical Contacts: Milton Shymlock, RII

(404) 331-5542 Thomas McElhinney, Res. Insp., Turkey Pt.

(305) 245-7669 Attachment: List of Recently Issued NRC Information Notices

Transmitted by memo to Carl Berlinger from RII dated 12/8/88

• SEE PREVIOUS CONCURRENCES C/OGCB: DOEA:NRR

CHBerlinger

03// 89 /89

• OGCB:DOEA:NRR *EMEB:DEST:NRR *SRXB:DEST:NRR RII *RPB:ARM

NPKadambi LBMarsh MWHodges MShymlock TechEd

02/27/89 03/02/89 03/02/89 03/ /89 03/02/89

IN 89-XX

March xx, 1989 protection (by opening on demand) during low-temperature operation. Shearon

Harris utilizes two of the three PORVs for the LTOP system.

The design basis of the licensee's LTOP is to protect the RCS from overpressure

when the transient was limited to: (1) start of an0 idle reactor coolant pump

with secondary-side water temperature less than 50 F above RCS cold-leg temper- ature or (2) start of a charging safety injection pump and its injection into a

water-solid RCS. The PORV setpoints were calculated to maintain the RCS below

the maximum allowable system pressure given in 10 CFR 50 Appendix G. The

setpoint calculations assumed a valve opening time of 2.0 seconds in determin- ing the possible overshoot. The inspectors noted if the actual valve opening

times were greater than 2.0 seconds; then the pressure overshoot could be

greater than originally calculated. A significant increase in valve opening

time could result in the 10 CFR 50 Appendix G limits being exceeded during a

design-basis transient.

The PORVs were stroked in the open direction so that the licensee could perform

the time-to-close test. However, the surveillance procedure does not require

that the time to open be determined, and this was not done.

Discussion:

The basic issue in these three cases is that the licensee's inservice testing

of its low-pressure overpressure-protection (LTOP) systems may be inadequate.

Stroke time requirements stipulated in safety evaluation reports of the

licensee's LTOP systems were not being transferred into IST requirements and

eventually, into surveillance test procedures. The ASME Code,Section XI,

paragraph IWV-3400, requires valves to be exercised to the position required to

fulfill their function. Therefore, not testing the LTOP PORVs in the open

direction is a concern.

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 regional

office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Technical Contacts: Milton Shymlock, RII

(404) 331-5542 Thomas McElhinney, Res. Insp., Turkey Pt.

(305) 245-7669 Attachment: qist nf Rpepntlv Issued NRC Information Notices

Transmitted by memo to Carl Berlinger from RII dated 12/8/88 0

• SEE PREVIOUS CONCURRENCES D/DOEA:NRR C/OGCB:DOEA:NRR

CERossi CHBerlinger

03/ /89 03/ /89

• OGCB:DOEA:NRR *EMEB:DEST:NRR *SRXB:DEST:NRR RII-reAl Q *RPB:ARM

NPKadambi LBMarsh MWHodges MShyml oI echEd

02/27/89 03/02/89 03/02/89 O3 /69/89 kjj.. 03/02/89

IN 89-XX

February xx, 1989 Page 2 of

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 regional

office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Technical Contacts: Milton Shymlock, RII

(404) 331-5542 Thomas McElhinney, Res. Insp., Turkey Pt.

(305) 245-7669 Attachment: List of Recently Issued NRC Information Notices

• Transmitted by memo to Carl Berlinger from RT dated _ __-_

D/DOEA:NRR C/OGCB:DOEA:NRR

CERossi CHBerlinger

02/ /89 02/ /89 OGC:DOEA:NRR EB:DEST:NRR B:DEST:NRR RII RPB:ARM

LBMarsh MWHodges MShymlock TechEd I

NPKadambi

02/27/89 0 /89 Y/;z /89 02/ /89 ee7-- 7t89- °3/3/h89

3 PL

'9