Information Notice 1986-89, Uncontrolled Rod Withdrawal Because of a Single Failure

Uncontrolled Rod Withdrawal Because of a Single Failure

ML031250343
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:	10/16/1986
From:	Jordan E NRC/IE
To:
References
IN-86-089, NUDOCS 8610100105
Download: ML031250343 (4)

-t -SSINS No.:

IN 86-89 6835 UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF INSPECTION AND ENFORCEMENT

WASHINGTON, D.C. 20555 October 16, 1986 ROD WITHDRA4AL BECAUSI If

IE-INFORMATION NOTICE NO. 86-89:- UNCONTROLLED

A SINGLE FAILURE

Addressees

holding an operating license or a

All boiling water reactor (BWR) facilities

construction permit.

Purpose

generic problem with a

This notice is to alert recipients of a potentially

control rod drift to the full-out

single failure that can cause both a single Recipients are expected to

position and then failure to insert on demand. their facilities and consider

review the information for applicability to problems occurring at their

actions, if appropriate, to preclude similar in this information notice do not

facilities. However, suggestions contained specific action or written response

constitute NRC requirements; therefore, no

is required.

Description of Circumstances

station experienced an uncontrolled

On July 30, 1986, the Grand Gulf nuclear position while at 69 percent power.

single control rod withdrawal to the full-out 08 to position 10, the operator

When attempting to notch rod 20-45 from positionobserved indications that the rod

noticed "rod drift" and "rod block" alarms and The operator pressed the insert

was at position 12 and continuing to withdraw. of the."in" light and the

pushbutton several times and observed the illumination

attempts slowed the rod outward

"settle" light. The repeated notch insertionto full-out position 48. The

movement, but the rod continued to withdraw to travel from position 08 to

control rod took about 3 minutes and 10 seconds

position 48 (which is about normal settle speed).

by the Alarm Response Instructions.

The operator carried out the actions required reduced to 60 percent for thermal

As a conservative measure, reactor power was Once control of rod insertion

limit concerns, and a coupling check was performed.

44 and back to position 48 to test

was regained, the rod was placed at position inoperable, fully inserted, and

the rod withdrawal limiter. The rod was declared

hydraulically disarmed.

and bench checks were performed

To determine the cause of the event, inspections is designated 122 at some older

valve

on withdraw control valve, C11-F422. (This operation, and no fouling of

no sign of abnormal

BWRs.) The valve demonstrated that temporary particulate

the valve seat was evident. The licensee concluded

IN 86-89 October 16, 1986 accumulation on the valve seating surface caused an incomplete closure of

the

valve when the withdraw command was terminated, allowing drive water pressure

leak past the valve and force the drive piston downward. to

Subsequently, the withdraw control valve was replaced with a new valve and

control rod restored to service. During the upcoming refueling outage, the the

licensee plans to check the drive water filters and sample low stagnant points

in the system for particulates. The licensee has provided additional operator

instructions for control rod/drive malfunctions based on General Electric

Service

Information Letter (SIL) 292 that was issued in July 1979. The procedure

revisions include the following actions to be taken when control rods drive

with no "withdraw command" present: out

1. Application of continuous control rod insert signal until the rod reaches

zero. If the control rod continues to withdraw from zero, reinsert the

continuous control rod insert signal and hold until either the control rod

drive pressure can be reduced or someone can isolate the affected hydraulic

control unit (HCU) by closing the 103 drive water riser isolation and 105 exhaust water riser isolation valves on the HCU.

2. If the control rod drive does not respond to the insert signal, have

someone manually scram the rod from the HCU.

3. If the drive continues to demonstrate occurrences of inadvertent withdrawal, the control rod should be inserted to position zero and the drive should

valved out of service until the fault is located and corrected. After thebe

drive is valved out of service, the associated valve no. 122 and control

circuity should be checked and repaired if necessary.

Discussion:

There have been other instances when the withdrawal directional control

valve

caused uncontrolled rod withdrawal:

Plant name Date Cause

Pilgrim 4/8/78 122 Valve Corrosion Products

Browns Ferry 2 6/24/80 85-40C Valve Failed (85-40C is

TVA designation for 122 Valve)

In addition, there have been events when uncontrolled withdrawal has been

caused

by unknown reasons or a collet finger problem.

IN 86-89 October 16, 1986 information notice.

No specific action or written response is required by thisthe Regional Adminis- If you have questions about this matter, please contact

trator of the appropriate NRC regional office or this office.

A . Jordan, Director

Divi n of Emergency Preparedness

and Engineering Response

Office of Inspection and Enforcement

Eric Weiss, IE

(301) 492-9005 Attachment: List of Recently Issued IE Information Notices

Attachment 1 IN 86-09 October 16. 1986 LIST OFRECENTLY ISSUED

IE INFORMATION NOTICES

^-fe~tfon Oate ot

..:ce .c. 3Jc'#C: :ssse :Ss.ec tc

86-05 main Steam Safetv valve Test 10/16/86 All po-.* reacto'

Suo. 1 Failures Ana Ring Setting facilities holding

Adjustments an OL or CP ,

86-25 Traceability And Material 10/15/86 All power reactor

Control of Material Ana facilities holding

Sup I

Equipment. Particularly an OL or CP

Fasteners

86-68 Coaevnsatory Measures For 10/15/86 All power reactor

Prolonged Periods Of Security facilities holding

System Failures an OL or CP; fuel

fabrication and

processing facilities

86-67 Loss Of OffslttPower Upon An 10/10/86 All power reactor

Automatic Bus Transfer facilities holding

an OL or CP

96-86 Clarification Of Requirements 10/10/86 All registered users

For fabrication And Export Of of NAC certified

Certain Previously Approved - packages

Type S Packages

86-85 Enforcement Actions Against 10/3/86 All NRCmedical

Medical Licensees For licensees

willfull Failure To Report

Misadministrations

86-84 Rupture Of A Nominal 9/30/86 All NRC medical

40-1ill icuri* Iodine-125 institution licensees

Irachytherapy Seed Causing

Significant Spread Of

Radioactive Contamination

s6-63 Underground Pathways Into 9/19/86 All power reactor

Protected Areas, Vital Areas, facilities holding

Material Access Areas, And an OL or CP; fuel

Controlled Access Areas fabrication and

processing facilities

UPhTEO STATES OL a Operating License F IRST CLASS IAI. j

NUCLEAR REGULATORY COMMISSION CPmConstruction Permit POSTAGE & FEES PAlO

USh AC

WASHINGTON. D.C. 20Z6 *ASM O C

PERMIT No G67 OSFICIAL BUSINESS

PENALTY FOR PAIVATE USE. *m

1 972 04 03" 0'29 1 1CO1CYJFt.1JJMJ

POTA" G~:'ERAL ELECn'1C CO

E~APT 0 wITH7R"

PCPTLAINJ CP  ; 7 7C 4