Information Notice 1986-92, Pressurizer Safety Valve Reliability

Pressurizer Safety Valve Reliability

ML031250138
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:	11/04/1986
From:	Jordan E NRC/IE
To:
References
IN-86-092, NUDOCS 8610300067
Download: ML031250138 (4)

SSINS No.: 6835 IN 86-92- UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF INSPECTION AND ENFORCEMENT

WASHINGTON, D.C. 20555 November 4, 1986 VALVE RELIABILITY

IE INFORMATION NOTICE NO. 86-92: PRESSURIZER SAFETY

Addressees

an operating license or

All pressurized-water reactor (PWR) facilities holding

a construction permit.

Purpose

significant problems

This notice is provided to inform recipients of potentially

valves. It is expected that

pertaining to the reliability, of pressurizer safety to their facilities and

recipients will review the information for applicability problem from occurring

consider actions, if appropriate, to preclude a similar

in this information notice

at their facilities. However, suggestions contained specific action or written

do not constitute NRC requirements; therefore, no

response is required.

Description of Circumstances

St. Lucie 2:

Lucie 2 personnel bench

On April 17, 1986 while shut down for refueling, St. technical specification (TS)

have a

tested three pressurizer safety valves that at 2554 psig (14 psi above the

set point of 2515 +/- 1x psig. Valve V-1200 lifted psig (353 psi above the

maximum TS set point, valve V-1201 lifted at 2893 too much to test. The

maximum TS set point), and valve V-1202 was leaking bellows which allowed boric

problem with V-1201 was attributed to a hole in the

causing them to bind. The

acid to contaminate and corrode the valve internals point drift of V-1200 was

seat of V-1202 was badly steam cut. The minor set were repaired before

considered normal for 18 months operation. All valves

replacing them in service.

McGuire 1:

safety valve had

On September 2, 1986, McGuire 1 reported that a pressurizer set point. The

lifted at 2375 psig, 85 psi below the 2485 +/- 1% TS required

valve fully closed. This

primary system depressurized to 1800 psig before the

leak test. During

event occurred during pressurization for an inservice set point was determined

subsequent bench testing of that valve, the as-found

used to determine the

to be 2320 psig. Analysis showed that the three lifts Cocking of the spring, valve set point at the last test were trending downward.was considered to be the

probably because of debris under the spring or a burr, properly seated, the set

cause of the set point "drift." When the spring was

point stabilized.

8610300067

IN 86-92 November 4, 1986 The low pressure at which the valve reclosed is attributed by the licensee to

the setting of the blowdown adjusting ring, which deviated from the vendor's

recommended setting by 137 notches. The remaining pressurizer safety valves on

unit 1 were inspected and one other had misadjusted ring settings. The

misadjustment was attributed to on-site readjustment by maintenance personnel.

The correctly set rings on the third valve were set by the vendor's representa- tive. Unit 1 valves will be repaired and reset.

Unit 2 had two pressurizer safety valves set by the vendor's representative and

one set by plant maintenance personnel. The plant technician had recorded the

ring settings, which were the same as the vendor's recommendation. Therefore, Unit 2 valves were determined to be operable.

Arkansas Nuclear One, Unit 2:

On September 15, 1986 while at 29% power, ANO 2 experienced a spurious opening

and rapid reseating of two pressurizer safety valves, which resulted in an

increase in level and pressure in the quench tank and a 4 psig drop in reactor

coolant pressure. On September 25, 1986 following a reactor trip, quench tank

parameters and tail pipe temperatures indicated that one or both pressurizer

safety valves had lifted. Licensee tests showed that the setpoints of the valves

were lower than the TS required 2485 psig +/- 1%. One valve lifted at 2365 psig

and the other between 2430 and 2455 psig. It was determined that the wrong test

equipment had been used to set the lift pressure of the valves at the outage

prior to these events. The valve manufacturer sent a representative to the site

with the correct equipment. The valves have been correctly reset.

A search of licensee event reports from January 1, 1983 to the present shows

that 20 other evepts involving 32 valves occurred. The problems were: 18 valves

with set point drift, 12 valves with seat leakage, 1 valve with set pressure

high and 1 valve designated as inoperable. Attachment 1 contains the details

of this compilation. Other information on the subject of safety valve

performance and reliability may be found in information notices 86-05;

86-05, Supplement 1; and 86-56, the subject of which are main steam safety

valves.

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.

4,)!& 5 ector

Oivisiji of Emergency Preparedness

and Ehgineering Response

Officdof Inspection and Enforcement

Mary S. Wegner, IE

(301) 492-4511 Attachments:

1. Other Pressurizer Safety Valve Problems

2. List of Recently Issued IE Information Notices

Attachment 1 IN 86-92 TO PRESENT

OTHER PRESSURIZER SAFETY VALVE PROBLEMS FROM 01/01/83 PLANT NO. VALVES

INOPERABLE

SEQUOYAH 1 1 LEAKING

SALEM 2 3 SALEM 1 3 MILLSTONE 2 1 SEQUOYAH 2 1 SEQUOYAH 2 1 BEAVER VALLEY 1 1 SUMMER 1 SEQUOYAH 2 1 SET POINT DRIFT

CALVERT CLIFFS 2 1 BEAVER VALLEY 1 1 SET POINT DRIFT HIGH

FT CALHOUN 1 SALEM 2 3 SALEM 1 3 MILLSTONE 2 1 PALISADES 1 SUMMER 1 YANKEE-ROWE 1 SET POINT DRIFT LOW

ANO 1 1 SEQUOYAH 1 1 SEQUOYAH 2 3 SET PRESSURE HIGH

YANKEE-ROWE 1

Attactment 2 IN 96-92 November 4. 1986 LIST OF RECENTLY ISSUED

IE INFObMATION NOTICES

UI UUb , I'

Date of

Nootice No. Issued to

I Subiject

68-91 Limiting Acc '55 IV3/86 All power reactor

Autherizat1o nns facilities holding

in OL or CP; fuel

fabrication and

processing facilities

Requests To Dispose Of Very 11/3/66 All power reactor

K6-90

Low-Level Radioactive Waste facilities holding

Pursuant to 10 CFR20 302 an OL or CP

t6-e9 Uncontrolled Rod Vlthdrawel 10/16/t6 All WR facilities

Because Of A Single Failure holding an OL or CP

t6-05 Rain Ste Safety Valve Test 10/16/86 All power reactor

Sup. 1 Failures And Ring Setting facilities holding

Adjustments an OL or CP

Traceability And Material 10/15/U6 All power reactor

e6-25 Sup. 1 Control of Material And facilities holding

Equipment, Particularly an OL or CP

Fasteners

86-t8 Compensatory measures For 10/15/U6 All power reactor

Prolonged Periods Of Security facilities holding

System Failures an OL or CP; fuel

fabrication and

processing facilities

Loss Ot Offsite Power Upon An 10/10/86 All power reactor

"-tJ fpcilities holding

Automatic tus Transfer

an OL or CP

Clarification Of Requirements 10/10/t6 All registered users

t6-U6 of NRC certif ied

For Fabrication And Export Of

Certain Previously Approved packages

Type t Packages

86-85 Enforcement Actions Against 10/3/86 All NRC medical

Medical Licensees For IIcensees

Willfull Failure To Report

isatdmisistrations

OL a Operating License

CP a Construction Permit

UNITED STATES FIRST CLASS MAIL

6 FEES PASO

POSTAGE

NUCLEAR REGULATORY COMMISSION USNRC

WASHINGTON, D.C. 20555 WASH O.C.

PERMIT No G47 OFFICIAL BUSINESS

PENALTY FOR PRIVATE USE. *300

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