SSINS No.: 6835 IN 86-82
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C.
20555
September 16, 1986
IE INFORMATION NOTICE NO. 86-82: FAILURES OF SCRAM DISCHARGE VOLUME VENT AND
DRAIN VALVES
Addressees
All nuclear power reactor facilitiesholding an operating license or a con- struction permit.
Purpose
This notice is provided to inform recipients of a potentially significant problem
pertaining to failures of the Hammel-Dahl valves used as vent and drain valves
in the control rod drive (CRD) systems of certain boiling water reactors.
It is
suggested that recipients will review the information for applicability to their
facilities and consider actions, if appropriate, to preclude a similar problem
from occurring at their facilities.
However, suggestions contained in this
information notice do not constitute NRC requirements; therefore, no specific
action or written response is required.
Description of Circumstances
On February 8, 1985, the General Electric Company (GE) notified the NRC of a
coupling failure of the 2"-2500# Hammel-Dahl valve used as a CRD drain valve
in the scram discharge volume (SDV).
The coupling connected the air actuator
to the valve stem and its failure prevented the valve from fully opening or
closing.
This failure had occurred during equipment qualification in a labor- atory and was due to automatic actuation while the manual handwheel was parti- ally engaged.
GE identified the 2"-600#, 1"-2500#, and 1"-600# as having the same coupling
design.
The 1" valves are used as SOV vent valves.
On May 13,1985, GE issued service information letter (SIL) 422 to inform its
customers of the potential for failure of the valve and recommended actions.
In SIL 422, GE mentions a related problem that occurred at an operating plant.
Subsequently, two additional operating plants have experienced valve failures
caused by partially engaged handwheels: Limerick in November of 1985 and Hope
Creek in May of 1986.
Limerick found an SDV drain valve with its handwheel off
the neutral position and attempted to actuate the valve from the control room.
The valve would not operate.
Hope Creek found a coupling failed in a drain
valve and the handwheel partially engaged.
8607110321
i
IN 86-82 September 16, 1986 Discussion:
The SDV vent and drain valves are primary containment isolation valves that are
normally open while the plant is operating.
There are two valves in series in
each vent and drain line.
They allow water from the normal CRD seal leakage to
drain to radwaste rather than accumulate in the SDV.
When a scram occurs, the
vent and drain valves close to isolate reactor coolant from radwaste.
GE SIL 422 recommends that licensees "provide adequate training, operating
procedures, and checks to help assure that the handwheels of the valves are in
the neutral position to prevent inadvertent engagement of the handwheel during
automatic actuation of the valves."
When the handwheel is engaged or partially engaged, the automatic actuation
function may be prevented, or, if it occurs, may damage the actuator or stem of
the valve, causing it to fail in its "as-is" position.
These valves are primary
containment isolation valves.
If two valves in series fail open, a discharge
path will exist for reactor coolant to drain to the plant drain system.
This
path can be isolated by resetting the scram signal or by manually closing the
- 102 or #112 valves on each associated hydraulic control unit (HCU).
(There are
approximately 92 HCUs per SDV.)
If the vent and drain valves fail closed, the
CRD seal leakage will collect in the SDV until the SDV level reaches the scram
set point.
The failure of either redundant vent valve and or either redundant drain valve
represent a degradation of safety systems (CRD, primary containment, and the
primary containment isolation system) and could result in unnecessary challenges
of the reactor protection system.
Licensee corrective actions have included
training, procedure revision, and enhanced surveillance as well as adding
administrative controls to maintain the handwheels in the neutral position.
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.
- d-w
o
//
Z
or
Divisi
of Emergency Preparedness
and
gineering Response
Office of Inspection and Enforcement
Technical Contact:
Mary S. Wegner, IE
(301)492-4511 Attachment:
List of Recently Issued IE Information Notices
Attachment 1
IN 86-82
September 16, 1986
LIST OF RECENTLY ISSUED
IE INFORMATION NOTICES
Information
Date of
Notice No.
Subject
Issue
Issued to
86-81
86-80
86-79
86-78
86-77
86-76
86-75
86-74
86-73
86-72 Broken Inner-External Closure 9/15/86 Springs On Atwood & Morrill
Main Steam Isolation Valves
Unit Startup With Degraded
9/12/86
High Pressure Safety Injection
System
Degradation Or Loss Of
9/2/86
Charging Systems At PWR
Nuclear Power Plants Using
Swing-Pump Designs
Scram Solenoid Pilot Valve
9/2/86 (SSPV) Rebuild Kit Problems
Computer Program Error Report 8/28/86 Handling
All power reactor
facilities holding
an OL or CP
All power reactor
facilities holding
an OL or CP
All power reactor
facilities holding
an OL or CP
All BWR facilities
holding an OL or CP
All power reactor
facilities holding
an OL or CP and
nuclear fuel man- ufacturing facilities
All power reactor
facilities holding
an OL or CP
All power reactor
facilities holding
an OL or CP
All BWR facilities
holding an OL or CP
All power reactor
facilities holding
an OL or CP
-All power reactor
facilities holding
an OL or CP
Problems Noted In Control
Room Emergency Ventilation
Systems
Incorrect Maintenance
Procedure On Traversing
Incore Probe Lines
8/28/86
8/21/86 Reduction Of Reactor Coolant 8/20/86 Inventory Because Of Misalign- ment Of RHR Valves
Recent Emergency Diesel
Generator Problems
Failure 17-7 PH Stainless
Steel Springs In Valcor
Valves Due to Hydrogen
Embrittlement
8/20/86
8/19/86 OL = Operating License
CP = Construction Permit
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| list | - Information Notice 1986-01, Failure of Main Feedwater Check Valves Causes Loss of Feedwater System Integrity and Water-Hammer Damage (6 January 1986, Topic: Feedwater Heater)
- Information Notice 1986-02, Failure of Valve Operator Motor During Environmental Qualification Testing (6 January 1986)
- Information Notice 1986-03, Potential Deficiencies in Enviromental Qualification of Limitorque Motor Valve Operator Wiring (14 January 1986)
- Information Notice 1986-04, Transient Due to Loss of Power to Intergrated Control System at a Pressurized Water Reactor Designed by Babcock & Wilcox (31 January 1986)
- Information Notice 1986-05, Main Steam Safety Valve Test Failures and Ring Setting Adjustments (31 January 1986)
- Information Notice 1986-06, Failure of Lifting Rig Attachment, While Lifting Upper Guide Structure at St. Lucie Unit 1 (3 February 1986, Topic: Control of Heavy Loads)
- Information Notice 1986-06, Failure of Lifting Rig Attachment, while Lifting Upper Guide Structure at St. Lucie Unit 1 (3 February 1986)
- Information Notice 1986-07, Lack of Detailed Instruction & Inadequate Observance of Precautions During Maintenance & Testing of Diesel Generator Woodward Governors (3 February 1986, Topic: Overspeed trip, Overspeed)
- Information Notice 1986-08, Licensee Event Report (LER) Format Modification (3 February 1986, Topic: GOTHIC)
- Information Notice 1986-09, Failure of Check & Stop Check Valves Subjected to Low Flow Conditions (3 February 1986)
- Information Notice 1986-10, Degradation of Reactor Coolant System Pressure Boundary Resulting From Boric Acid Corrosion. (5 January 1995, Topic: Boric Acid, Stress corrosion cracking)
- Information Notice 1986-10, Degradation of Reactor Coolant System Pressure Boundary Resulting from Boric Acid Corrosion (5 January 1995, Topic: Boric Acid, Stress corrosion cracking)
- Information Notice 1986-10, Feedwater Line Break (10 November 1988, Topic: Coatings, Anchor Darling)
- Information Notice 1986-11, Anomalous Behavior of Recirculation Loop Flow in Jet Pump BWR Plants (31 December 1986)
- Information Notice 1986-13, Standby Liquid Control Squib Valves Failure to Fire (5 August 1986, Topic: Squib)
- Information Notice 1986-13, Standby Liquid Control System Squib Valves Failure to Fire (21 February 1986, Topic: Squib)
- Information Notice 1986-14, Overspeed Trips of Afw, HPCI & RCIC Turbines (26 August 1991, Topic: Overspeed trip, Overspeed)
- Information Notice 1986-14, Overspeed Trips of AFW, HPCI & RCIC Turbines (26 August 1991, Topic: Overspeed trip, Overspeed)
- Information Notice 1986-15, Loss of Offsite Power Caused by Problems in Fiber Optics Systems (10 March 1986, Topic: Squib, Loss of Offsite Power)
- Information Notice 1986-16, Failures to Identify Containment Leakage Due to Inadequate Local Testing of BWR Vacuum Relief System Valves (11 March 1986, Topic: Squib, Local Leak Rate Testing, Integrated leak rate test)
- Information Notice 1986-17, Update of Failure of Automatic Sprinkler System Valves to Operate (24 March 1986, Topic: Squib)
- Information Notice 1986-18, NRC On-Scene Response During a Major Emergency (26 March 1986, Topic: Squib, Backfit)
- Information Notice 1986-19, Reactor Coolant Pump Shaft Failure at Crystal River (21 March 1986, Topic: Squib)
- Information Notice 1986-20, Low-Level Radioactive Waste Scaling Factors, 10 CFR Part 61 (28 March 1986, Topic: Squib)
- Information Notice 1986-21, Recognition of American Society of Mechanical Engineers Accreditation Program for N Stamp Holders (31 March 1986, Topic: Squib)
- Information Notice 1986-22, Underresponse of Radiation Survey Instrument to High Radiation Fields (31 March 1986, Topic: High Radiation Area, Squib)
- Information Notice 1986-23, Excessive Skin Exposures Due to Contamination with Hot Particles (9 April 1986, Topic: Loss of Offsite Power)
- Information Notice 1986-23, Excessive Skin Exposures due to Contamination with Hot Particles (9 April 1986, Topic: Loss of Offsite Power)
- Information Notice 1986-24, Respirator Users Notice: Increased Inspection Frequency for Certain Self-Contained Breathing Apparatus Air Cylinders (11 April 1986, Topic: Hydrostatic)
- Information Notice 1986-25, Traceability and Material Control of Material and Equipment, Particularly Fasteners (11 April 1986)
- Information Notice 1986-26, Potential Problems in Generators Manufactured by Electrical Products Incorporated (17 April 1986)
- Information Notice 1986-27, Access Control at Nuclear Facilities (21 April 1986, Topic: Contraband)
- Information Notice 1986-28, Telephone Numbers to the NRC Operations Center and Regional Offices (24 April 1986)
- Information Notice 1986-29, Effects of Changing Valve Moter-Operator Switch Settings (25 April 1986)
- Information Notice 1986-30, Design Limitations of Gaseous Effluent Monitoring Systems (29 April 1986)
- Information Notice 1986-31, Unauthorized Transfer and Loss of Control of Industrial Nuclear Gauges (14 July 1986)
- Information Notice 1986-32, Request for Collection of Licensee Radioactivity Measurements Attributed to Chernobyl Nuclear Plant Accident (2 May 1986, Topic: Chernobyl, Potassium iodide)
- Information Notice 1986-33, Information for Licensee Regarding the Chernobyl Nuclear Plant Accident (6 May 1986, Topic: Chernobyl, Potassium iodide)
- Information Notice 1986-34, Improper Assembly, Material Selection, & Test of Valves & their Actuators (13 May 1986)
- Information Notice 1986-34, Improper Assembly, Material Selection, & Test of Valves & Their Actuators (13 May 1986)
- Information Notice 1986-35, Fire in Compressible Material at Dresden Unit 3 (15 May 1986, Topic: Chernobyl)
- Information Notice 1986-36, Change in NRC Practice Regarding Issuance of Confirming Letters to Principal Contractors (16 May 1986, Topic: Chernobyl)
- Information Notice 1986-37, Degradation of Station Batteries (16 May 1986, Topic: Chernobyl)
- Information Notice 1986-38, Deficient Operator Actions Following Dual Function Valve Failures (20 May 1986, Topic: Chernobyl)
- Information Notice 1986-39, Failures of RHR Pump Motors and Pump Internals (20 May 1986, Topic: Chernobyl)
- Information Notice 1986-40, Degraded Ability to Isolate the Reactor Coolant System from Low-Pressure Coolant Systems in Bwrs (5 June 1986, Topic: Chernobyl)
- Information Notice 1986-40, Degraded Ability to Isolate the Reactor Coolant System from Low-Pressure Coolant Systems in BWRs (5 June 1986, Topic: Chernobyl)
- Information Notice 1986-41, Evaluation of Questionable Exposure Readings of Licensee Personnel Dosimeters (9 June 1986, Topic: Chernobyl)
- Information Notice 1986-42, Improper Maintenance of Radiation Monitoring Systems (9 June 1986, Topic: Temporary Modification, Chernobyl)
- Information Notice 1986-43, Problems with Silver Zeolite Sampling of Airborne Radioiodine (10 June 1986, Topic: Chernobyl)
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