Information Notice 1998-14, Undocumented Changes to Non-Power Reactor Safety System Wiring: Difference between revisions

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{{#Wiki_filter:UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR REACTOR REGULATIONWASHINGTON, D.C. 20555-0001April 20, 1998NRC INFORMATION NOTICE 98-14: UNDOCUMENTED CHANGES TO NON-POWERREACTOR SAFETY SYSTEM WIRING
{{#Wiki_filter:UNITED STATES NUCLEAR REGULATORY
 
COMMISSION
 
===OFFICE OF NUCLEAR REACTOR REGULATION===
WASHINGTON, D.C. 20555-0001 April 20, 1998 NRC INFORMATION
 
NOTICE 98-14: UNDOCUMENTED
 
CHANGES TO NON-POWER REACTOR SAFETY SYSTEM WIRING


==Addressees==
==Addressees==
All holders of operating licenses or construction permits for test and research reactors.
All holders of operating
 
licenses or construction
 
permits for test and research reactors.


==Purpose==
==Purpose==
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to informaddressees of undocumented modifications that have occurred in the scram system wiring oftwo research reactors. In the first case, the modification in conjunction with a switch failureresulted in the reactor being operated for a short time without any technical specification (TS)required scrams. In the second case, because of a modification, a switch failure could haveresulted in a TS required scram being disabled. It is expected that recipients will review theinformation for applicability to their facilities and consider action, as appropriate, to avoid similarproblems. However, suggestions contained in this information notice are not NRCrequirements; therefore, no specific action or written response is required.
The U.S. Nuclear Regulatory
 
Commission (NRC) is issuing this information
 
notice to inform addressees
 
of undocumented
 
modifications
 
that have occurred in the scram system wiring of two research reactors.
 
In the first case, the modification
 
in conjunction
 
with a switch failure resulted in the reactor being operated for a short time without any technical
 
specification (TS)required scrams. In the second case, because of a modification, a switch failure could have resulted in a TS required scram being disabled.
 
It is expected that recipients
 
will review the information
 
for applicability
 
to their facilities
 
and consider action, as appropriate, to avoid similar problems.
 
However, suggestions
 
contained
 
in this information
 
notice are not NRC requirements;  
therefore, no specific action or written response is required.Description
 
of Circumstances
 
Oregon State Universty On the morning of February 17, 1998, the TRIGA non-power
 
reactor at Oregon State University (OSU) had completed
 
a routine 14-minute
 
run at 15 watts of power to perform core excess reactivity
 
measurements.
 
An attempt was made to manually scram the reactor at the end of the run using the scram button. When the manual scram button did not work, the operators
 
next step was to turn off power to the scram circuit using the reactor's
 
three-position
 
key switch.This switch-1s
 
OFF, OPERATE, and RESET positions
 
with a spring return between the RESET and OPERATE positions.
 
As the operator touched the switch, the switch moved from a position between OPERATE and RESET to the OPERATE position.
 
The operator then tried the manual scram button again and this time it worked.The licensee determined
 
that a buildup of dirt prevented
 
the three-position
 
switch from returning to the OPERATE position.
 
When the switch is in the RESET position, the scram bus is disabled.
 
This switch dates to 1967 when the original console was installed.
 
The switch operated properly during preoperational
 
testing before startup.Upon further investigation, the licensee discovered
 
that the wiring of the scram circuit was different
 
from the wiring shown in the Instrument
 
Maintenance
 
Manual provided by the reactor vndr. Fgure I shows part of the circuitry
 
as designed.
 
If the key switch is in the OPERATE D 04151-'i ureg 1D s4 ows~g- lt;)X
 
K>IN 98-14 April 20, 1998 position, ac power is supplied from terminal block one, terminal number four (TBI -4) through TBI-9, to TB2-3, the A3 and Al contacts of the three-position
 
switch, and then the console power switch. This allows transformer
 
four (T4) to power the rod magnets. When the key is turned to RESET, this circuit is opened and the magnet current is cut off. This prevents rod withdrawal
 
if the rods are down, or causes the rods to drop if they are up. This design feature prevents a single failure of the three-position
 
switch from disabling
 
the scram circuits.
 
In the RESET position, power is supplied to the scram reset relays (K19, K20, and K24), which reset the scram relays (only one scram relay, K12, is shown). If the key switch sticks in the RESET position, the scram relay will continued
 
to be energized
 
by the reset relay even if a scram signal occurs. This is not a problem because the power would already be cut off to the magnets.Figure 2 shows the wiring as found in the OSU console. The wiring that was between TB1-9 and TB2-3 in the "as designed" circuit was between TBI-9 and TBIO-10 in the OSU console.As a result, there is power to the magnets when the switch is in the RESET or OPERATE position.The licensee concluded
 
that the location of the jumper was probably modified during initial installation
 
of the reactor console in 1967. This modification
 
was probably done to provide power to the *B deck 3 on the three-position
 
switch to power REACTOR ON lights.The licensee took a number of corrective
 
actions. The three-position
 
switch was removed, cleaned, relubricated, and reinstalled
 
in the console. The reactor console wiring was restored to its as-designed
 
condition.
 
The wiring in the scram circuitry
 
and in other non-scram-related
 
circuits was checked physically
 
and electronically
 
to demonstrate
 
that the wiring in the console is as designed.
 
The reactor startup procedure
 
was rewritten
 
to test that the magnet power is cut off when the three-position
 
switch is placed in the RESET position.
 
The reactor console was subject to routine startup checks and the semiannual
 
console check procedure.
 
The reactor vendor was contacted
 
to obtain checkout procedures
 
to confirm that all suggested surveillances
 
are done before reactor operation.
 
Texas A&M Universiy OSU quickly placed information
 
about the failure to scram on the Organization
 
of Test, Researth and Training Reactors (TRTR) list server. As a result, the staff at the Texas A&M University
 
N&clear Science Center checked the logic diagrams for its TRIGA research reactor and determined
 
that its reactor could not fail to scram. The Texas A&M console differs from the one at OSU in that there is no master reset equivalence
 
to the three-position
 
switch. Three of the scrams have push-button
 
spring-returned
 
switches that clear the locked-in
 
alarm on the console and allow the scram relay coil to be reenergized
 
if the signal is clear.The licensee also tested the circuit and determined
 
that each of the three scrams associated
 
with these switches could be defeated by holding its switch down in the RESET position (this simulated
 
a switch failure).
 
In this case, the failure of a single switch could prevent an individual
 
scram signal but would have not disabled all scrams. The licensee then checked the wiring diagrams for the console and discovered
 
that the wiring of the console matched the wiring diagrams.
 
The RESET switches were wired in parallel with the normally closed scram contacts.This wiring maintained
 
power to the magnets through one parallel path if the switch was
 
IN 9S*14 April 20, 1998 depressed, even if a scram contact opened in the other parallel path. The switches should have been wired in series. The licensee cannot determine
 
when the console was wired this way, but notes that the console underwent
 
a major upgrade in 1968. The logic diagram, drawn in 1976, which differs from the wiring diagram and the as-wired console, appears to have been based on system knowledge
 
of how it should be configured
 
rather than on the actual configuration.
 
To correct this situation, the licensee changed the wiring to put the RESET switch in series with the protective
 
action contacts, physically
 
verified console wiring for scram circuits, identified
 
various failure modes, and tested the console for proper operation.
 
Discussion
 
The circumstances
 
described
 
above demonstrate
 
the importance
 
of controlling
 
modifications, ensuring that all of the consequences
 
of a modification
 
are carefully
 
considered, and ensuring that design features in the scram circuitry
 
perform as designed.
 
Careful reviews of modifications
 
through the safety review process can be an effective
 
method to help to ensure that unintended
 
deleterious
 
effects from modifications
 
do not occur. The identification
 
of safety system design features could lead to surveillances
 
or tests that could prevent the occurrence
 
of similar problems.
 
The staff noted that many licensees
 
contacted
 
the NRC to discuss the results of testing performed
 
on consoles because of the information
 
placed on the TRTR listed server by OSU.This information
 
notice requires no specific action or written response.
 
If you have any questions
 
about the information
 
in this notice, please contact the technical
 
contact listed below.Jack Roe, Acting Director Division of Reactor Program Management
 
===Office of Nuclear Reactor Regulation===
Technical
 
contact: Alexander
 
Adams, Jr., NRR 301-415-1127.E-mail: axa@nrc.gov
 
Attachments:
1. Figure 1, *Reactor Operate Circuit, As-Designed" 2. Figure 2, Reactor Operate Circuit -As Found" 3. List of Recently Issued NRC Information
 
Notices-L
 
vD C Em DOCUMENT NAME: G:WVERN\OSUSCRAM.INF
 
Tech Editor concurred
 
on 3126/98 To receive a copy of this document, indicate in the box C=Copy wlo attachmentlenclosure
 
E=Copy with attachmentfenclosure
 
N = NIcopy OFFICE PDND (A)D:PDND
 
C:PECB (A)D:DRPIV\S
 
A NAME AAdams* MMendonca*
JStolz* JRoe*[DATE 03/30198 03/30/98 04/06/98 04/13/98 5'OFFICIAL RECORD COPY
 
P6-3 5 P22-1 0 TB10 Switched AC (H)T P2 f6 2 T T1 Bi B36P22-l1 T910 4 T4 50 Operate Permissive
 
Jumper 1 3 A .34P3-21 TB2 1 4TB` P3-202 CBB1l A4 >3 P5-4 AC (N) *OFF 0J5) *OPERATE (*RESET Part of Console Key Switch TBl 0 dAC (N)External Scram AC (N)-. (Kl12 K19 K20 K24 Kl2 l H tK1 6-7 'Switched AC (H)Fiaure I. Reactor OnprAt0 Circiuit.
 
Aq-dpeinnadr
 
..I-- -..--. -V-- --- -..-- .-, --- --- .U.-
Si9 P6-35 P22-10 TB10 TB10 Si "KSwitched
 
AC (H)82 AC (N) TB1 POWER OR P6-36 P22-11 TB10 E3 T4 P5-1 A2 .341 P3(2 T82 P3-0 Cal 8L P5-4 AC (N) f*OF*OPERATE* RESET Part of Console Key Switch (TB1 0 SIAC (N)Exterral Scram NO AC (N)0- -- 9X6-7 l_______ Switched AC (H) f5B Ftc Figr 0. Reco prt 0cft- A Fud
 
.I Attachment
 
3 IN 98-14 April20, 1998 LIST OF RECENTLY ISSUED NRC INFORMATION
 
NOTICES Information
 
Date of Notice No. Subject Issuance Issued to 98-13 Post-Refueling
 
Outage Reactor 4120/98 All holders of operating
 
licenses Pressure Vessel Leak Testing Before Core Criticality
 
for nuclear power reactors except those that have permanently
 
ceased operations
 
and have certified
 
that fuel has been permanently
 
removed from the reactor vessel 98-12 9&-1 1 Licensees'
 
===Responsibilities===
Regarding
 
Reporting
 
and Follow-up Requirements
 
for Nuclear-Powered
 
Pacemakers
 
Cracking of Reactor Vessel Internal Baffle Former Bolts in Foreign Plants 4/3/98 3/25/98 All U.S. Nuclear Regulatory
 
Commission
 
nuclear pacemaker licensees All holders of operating
 
licensing for pressurized-water
 
reactors (PWRs) except those who have ceased operation
 
and have certified
 
that fuel has been permanently
 
removed from the reactor vessel.95-52, Supp. 1 Fire Endurance
 
Test Results for Electrical
 
===Raceway Fire Barrier Systems Constructed===
From 3M Company Interam-ire Barrier Materials 3/17/98 All holders of operating licenses for nuclear power reactors except those who have permanently
 
ceased operation
 
and have certified
 
that fuel has been permanently
 
removed from the reactor vessel.98-10 98-09 Probable Misadministrations
 
Occurring
 
===During Intravascular===
Brachytherapy
 
With The Novoste Beta-Cath
 
System Collapse Of An Isocam II Dual-Headed
 
Nuclear Medicine Gamma Camera 3/9/98 3/5/98 All Medical Licensees All Medical Licensees OL = Operating
 
License CP = Construction
 
Permit
 
* KIN ?-14 April 20, 1998 depressed, even if a scram contact opened in the other parallel path. The switches should have been wired in series. The licensee cannot determine
 
when the console was wired this way, but notes that the console underwent
 
a major upgrade in 1968. The logic diagram, drawn in 1976, which differs from the wiring diagram and the as-wired console, appears to have been based on system knowledge
 
of how it should be configured
 
rather than on the actual configuration.
 
To correct this situation, the licensee changed the wiring to put the RESET switch in series with the protective
 
action contacts, physically
 
verified console wiring for scram circuits, identified
 
various failure modes, and tested the console for proper operation.
 
Discussion
 
The circumstances
 
described
 
above demonstrate
 
the importance
 
of controlling
 
modifications, ensuring that all of the consequences
 
of a modification
 
are carefully
 
considered, and ensuring that design features in the scram circuitry
 
perform as designed.
 
Careful reviews of modifications
 
through the safety review process can be an effective
 
method to help to ensure that unintended
 
deleterious
 
effects from modifications
 
do not occur. The identification
 
of safety system design features could lead to surveillances
 
or tests that could prevent the occurrence
 
of similar problems.
 
The staff noted that many licensees
 
contacted
 
the NRC to discuss the results of testing performed
 
on consoles because of the information
 
placed on the TRTR listed server by OSU.This information
 
notice requires no specific action or written response.
 
If you have any questions
 
about the information
 
in this notice, please contact the technical
 
contact listed below.orig /sfd by D. B. Matthews FOR Jack Roe, Acting Director Division of Reactor Program Management
 
===Office of Nuclear Reactor Regulation===
Technical
 
contact: Alexander
 
Adams, Jr., NRR 301-415-1127 E-mail: axa~nrc.gov
 
Attachments:
1. Figure 1, OReactor Operate Circuit, As-Designed'
2. Figure 2, uReactor Operate Circuit -As Found" 3. List of Recently Issued NRC Information
 
Notices DOCUMENT NAME: G:WVERN\OSUSCRAM.INF
 
Tech Editor concurred
 
on 3/26198 To receive a copy of this document indicate In the box C=Copy wlo attachmentenclosure
 
E=Copy with attachmentlenclosure
 
N = No copy OFFICE PDND (A)D:PDND
 
I C:PECB Il (A)D:DRPM
 
Il NAME AAdams* MMendonca*
JStolz* JRoe*lDATE _ 03/30/98 03/30/98 04106198 j 04/13/98 OFFICIAL RECORD COPY
 
-- INbe14 April 20, 1998 depressed, even if a scram contact opened in the other parallel path. The switches should have been wired in series. The licensee cannot determine
 
when the console was wired this way, but notes that the console underwent
 
a major upgrade in 1968. The logic diagram, drawn in 1976, which differs from the wiring diagram and the as-wired console, appears to have been based on system knowledge
 
of how it should be configured
 
rather than on the actual configuration.
 
To correct this situation, the licensee changed the wiring to put the RESET switch in series with the protective
 
action contacts, physically
 
verified console wiring for scram circuits,.identified
 
various failure modes, and tested the console for proper operation.
 
Discussion
 
The circumstances
 
described
 
above demonstrate
 
the importance
 
of controlling
 
modifications, ensuring that all of the consequences
 
of a modification
 
are carefully
 
considered, and ensuring that design features in the scram circuitry
 
perform as designed.
 
Careful reviews of modifications
 
through the safety review process can be an effective
 
method to help to ensure that unintended
 
deleterious
 
effects from modifications
 
do not occur. The identification
 
of safety system design features could lead to surveillances
 
or tests that could prevent the occurrence
 
of similar problems.
 
The staff noted that many licensees
 
contacted
 
the NRC to discuss the results of testing performed
 
on consoles because of the information
 
placed on the TRTR listed server byOSU.This information
 
notice requires no specific action or written response.
 
If you have any questions
 
about the information
 
in this notice, please contact the technical
 
contact listed below.Jack Roe, Acting Director Division of Reactor Program Management
 
===Office of Nuclear Reactor Regulation===
Technical
 
contact: Alexander
 
Adams, Jr., NRR 301-415-1127 E-mail: axa@nrc.gov
 
Attachments:
1. Figure 1, uReactor Operate Circuit, As-Designed" 2. Figure 2, "Reactor Operate Circuit -As Found" 3. List of Recently Issued NRC Information
 
Notices DOCUMENT NAME: G:WVERNOSUSCRAM.INF
 
Tech Editor concurred
 
on 3/26198 To receive a copy of this document, indicate in the box C=Copy wlo attachmentlenclosure
 
E=Copy with attachmentenclosure
 
N = Nlcopy I OFFICE PDND I (A)D:PDND
 
l C:PECB I (A)D:DRP NAME AAdams* MMendonca*
JStoz* JRoe*l DATE 03/30/98 03/30/98 04/06/98 04/13/98 OFFICIAL RECORD COPY
 
IN' XX .K ApexL 1998 (this simulated
 
a switch failure).
 
In this case, the failure of a single switch could preve an individual
 
scram signal but would have not disabled all scrams. The licensee then ecked the wiring diagrams for the console and discovered
 
that the wiring of the console moed the wiring diagrams.
 
The RESET switches were wired in parallel with the normall y-losed scram contacts.
 
This wiring maintained
 
power to the magnets through one paralle ath if the switch was depressed, even if a scram contact opened in the other parallel pathThe switches should have been wired in series. The licensee cannot determine
 
when the sole was wired this way, but notes that the console underwent
 
a major upgrade in 1968. e logic diagram, drawn in 1976, which differs from the wiring diagram and the as-wired co sole, appears to have been based on system knowledge
 
of how i should be configured
 
rat r than on the actual configuration.
 
To correct this situation, the licensee changed the wiring put the RESET switch in series with the protective
 
action contacts, physically
 
verified conso wiring for scram circuits, identified
 
various failure modes, and tested the console for probr operation.
 
Discussion
 
The circumstances
 
described
 
above demon ate the importance
 
of controlling
 
modifications, ensuring that all of the consequences
 
of a odification
 
are carefully
 
considered, and ensuring that design features in the scram circuit perform as designed.
 
Careful reviews of modifications
 
through the safety revie process can be an effective
 
method to help to ensure that unintended
 
deleterious
 
effects f m modifications
 
do not occur. The Identification
 
of safety system design features could lead o surveillances
 
or tests that could prevent the occurrence
 
of similar problems.
 
The staff note that many licensees
 
contacted
 
the NRC to discuss the results of testing performed
 
on consols because of the information
 
placed on the TRTR listed server by OSU.This information
 
notice r uires no specific action or written response.
 
If you have any questions
 
about the inf ation in this notice, please contact the technical
 
contact listed below.Jack Roe, Acting Director Division of Reactor Program Management
 
===Office of Nuclear Reactor Regulation===
Technical
 
c ctac: Alexander
 
Adams, Jr., NRR 301-415-1127 E-mail: axaenrc.gov
 
Attac ent: List of Recently Issued NRC Information
 
Notices DT e MENT NAME: G:WVERN\OSUSCRAM.INF
 
To receive a copy f this document.
 
indicate In the box C=Copy w/o attachmeE=Copy
 
with co OFFICE PDND I _ (A)D:PDND
 
l C:PE'CB (A)D:DR hl1 I NAME AAdams* MMendonca*
iQStolz JRoe Jk DATE 03/30198 03/30/98 g 4 /j3198 OFFICIAL RECORD COPY a-) .
 
IN'- XX_ ApiV..x, 1998 switch failure).
 
The licensee then checked the wiring diagrams for the console and discovered
 
that the wiring of the console matched the wiring diagrams.
 
In this case, the failure of a single switch could prevent an individual
 
scram signal but would have not disabled all scrams. The RESET switches were wired in parallel with the normally closed scram contacts.
 
This wiring maintained
 
power to the magnets through one parallel path if the switch was depressed, even if a scram contact opened in the other parallel path. The switches should have been wired in series. The licensee cannot determine
 
when the console was wired this way, but notes that the console underwent
 
a major upgrade in 1968. The logic diagram, drawn in 1976, which differs from the wiring diagram and the as-wired console, appears to have been based on system knowledge
 
of how it should be configured
 
rather than on the actual configuration.
 
To correct this situation, the licensee changed the wiring to put the RESET switch in series with the protective
 
action contacts, physically
 
verified console wiring for scram circuits, identified
 
various failure modes, and tested the console for proper operation.
 
Discussion
 
The circumstances
 
described
 
above demonstrate
 
the Importance
 
of controlling
 
modifications, ensuring that all of the consequences
 
of a modification
 
are carefully
 
considered, and ensuring that design features in the scram circuitry
 
perform as designed.
 
Careful reviews of modifications
 
through the safety review process can be an effective
 
method to help to ensure that unintended
 
deleterious
 
effects from modifications
 
do not occur. The identification
 
of safety system design features could lead to surveillances
 
or tests that could prevent the occurrence
 
of similar problems.This information
 
notice requires no specific action or written response.
 
If you have any questions
 
about the information
 
in this notice, please contact the technical
 
contact listed below.Jack Roe, Acting Director Division of Reactor Program Management
 
===Office of Nuclear Reactor Regulation===
Technical


==Description of Circumstances==
contact: Alexander
Oregon State UniverstyOn the morning of February 17, 1998, the TRIGA non-power reactor at Oregon State University(OSU) had completed a routine 14-minute run at 15 watts of power to perform core excessreactivity measurements. An attempt was made to manually scram the reactor at the end of therun using the scram button. When the manual scram button did not work, the operators nextstep was to turn off power to the scram circuit using the reactor's three-position key switch.This switch-1s OFF, OPERATE, and RESET positions with a spring return between theRESET and OPERATE positions. As the operator touched the switch, the switch moved from aposition between OPERATE and RESET to the OPERATE position. The operator then tried themanual scram button again and this time it worked.The licensee determined that a buildup of dirt prevented the three-position switch from returningto the OPERATE position. When the switch is in the RESET position, the scram bus isdisabled. This switch dates to 1967 when the original console was installed. The switchoperated properly during preoperational testing before startup.Upon further investigation, the licensee discovered that the wiring of the scram circuit wasdifferent from the wiring shown in the Instrument Maintenance Manual provided by the reactorvndr. Fgure I shows part of the circuitry as designed. If the key switch is in the OPERATE D04151-'i ureg 1D s4 ows~g- lt;)X


K>IN 98-14April 20, 1998 position, ac power is supplied from terminal block one, terminal number four (TBI -4) throughTBI-9, to TB2-3, the A3 and Al contacts of the three-position switch, and then the consolepower switch. This allows transformer four (T4) to power the rod magnets. When the key isturned to RESET, this circuit is opened and the magnet current is cut off. This prevents rodwithdrawal if the rods are down, or causes the rods to drop if they are up. This design featureprevents a single failure of the three-position switch from disabling the scram circuits. In theRESET position, power is supplied to the scram reset relays (K19, K20, and K24), which resetthe scram relays (only one scram relay, K12, is shown). If the key switch sticks in the RESETposition, the scram relay will continued to be energized by the reset relay even if a scram signaloccurs. This is not a problem because the power would already be cut off to the magnets.Figure 2 shows the wiring as found in the OSU console. The wiring that was between TB1-9and TB2-3 in the "as designed" circuit was between TBI-9 and TBIO-10 in the OSU console.As a result, there is power to the magnets when the switch is in the RESET or OPERATEposition.The licensee concluded that the location of the jumper was probably modified during initialinstallation of the reactor console in 1967. This modification was probably done to providepower to the *B deck3 on the three-position switch to power REACTOR ON lights.The licensee took a number of corrective actions. The three-position switch was removed,cleaned, relubricated, and reinstalled in the console. The reactor console wiring was restoredto its as-designed condition. The wiring in the scram circuitry and in other non-scram-relatedcircuits was checked physically and electronically to demonstrate that the wiring in the consoleis as designed. The reactor startup procedure was rewritten to test that the magnet power iscut off when the three-position switch is placed in the RESET position. The reactor consolewas subject to routine startup checks and the semiannual console check procedure. Thereactor vendor was contacted to obtain checkout procedures to confirm that all suggestedsurveillances are done before reactor operation.Texas A&M UniversiyOSU quickly placed information about the failure to scram on the Organization of Test,Researth and Training Reactors (TRTR) list server. As a result, the staff at the Texas A&MUniversity N&clear Science Center checked the logic diagrams for its TRIGA research reactorand determined that its reactor could not fail to scram. The Texas A&M console differs from theone at OSU in that there is no master reset equivalence to the three-position switch. Three ofthe scrams have push-button spring-returned switches that clear the locked-in alarm on theconsole and allow the scram relay coil to be reenergized if the signal is clear.The licensee also tested the circuit and determined that each of the three scrams associatedwith these switches could be defeated by holding its switch down in the RESET position (thissimulated a switch failure). In this case, the failure of a single switch could prevent an individualscram signal but would have not disabled all scrams. The licensee then checked the wiringdiagrams for the console and discovered that the wiring of the console matched the wiringdiagrams. The RESET switches were wired in parallel with the normally closed scram contacts.This wiring maintained power to the magnets through one parallel path if the switch was
Adams, Jr., NRR 301-415-1127 E-mail: axa@nrc.gov


IN 9S*14April 20, 1998 depressed, even if a scram contact opened in the other parallel path. The switches shouldhave been wired in series. The licensee cannot determine when the console was wired thisway, but notes that the console underwent a major upgrade in 1968. The logic diagram, drawnin 1976, which differs from the wiring diagram and the as-wired console, appears to have beenbased on system knowledge of how it should be configured rather than on the actualconfiguration.To correct this situation, the licensee changed the wiring to put the RESET switch in series withthe protective action contacts, physically verified console wiring for scram circuits, identifiedvarious failure modes, and tested the console for proper operation.DiscussionThe circumstances described above demonstrate the importance of controlling modifications,ensuring that all of the consequences of a modification are carefully considered, and ensuringthat design features in the scram circuitry perform as designed. Careful reviews ofmodifications through the safety review process can be an effective method to help to ensurethat unintended deleterious effects from modifications do not occur. The identification of safetysystem design features could lead to surveillances or tests that could prevent the occurrence ofsimilar problems. The staff noted that many licensees contacted the NRC to discuss the resultsof testing performed on consoles because of the information placed on the TRTR listed serverby OSU.This information notice requires no specific action or written response. If you have anyquestions about the information in this notice, please contact the technical contact listed below.Jack Roe, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contact: Alexander Adams, Jr., NRR301-415-1127.E-mail: axa@nrc.govAttachments:1. Figure 1, *Reactor Operate Circuit, As-Designed"2. Figure 2, Reactor Operate Circuit -As Found"3. List of Recently Issued NRC Information Notices-L vD C EmDOCUMENT NAME: G:WVERN\OSUSCRAM.INF Tech Editor concurred on 3126/98To receive a copy of this document, indicate in the box C=Copy wlo attachmentlenclosure E=Copy with attachmentfenclosure N = NIcopyOFFICE PDND (A)D:PDND C:PECB (A)D:DRPIV\S ANAME AAdams* MMendonca* JStolz* JRoe*[DATE 03/30198 03/30/98 04/06/98 04/13/98 5'OFFICIAL RECORD COPY
Attachment:  
List of Recently Issued NRC Information


P6-3 5 P22-1 0 TB10Switched AC (H)T P2 f6 2 T T1Bi B36P22-l1 T9104 T450 Operate Permissive Jumper 1 3A .34P3-21 TB2 14TB` P3-202CBB1l A4 >3P5-4AC (N) *OFF0J5) *OPERATE (*RESETPart of Console Key SwitchTBl 0dAC (N)External ScramAC (N)-. (Kl12K19 K20 K24Kl2 l H tK1 6-7 'Switched AC (H)Fiaure I. Reactor OnprAt0 Circiuit. Aq-dpeinnadr..I-- -..--. -V-- --- -..-- .-, --- --- .U.-
Notices DOCUMENT NAME: G:WVERN\OSUSCRAM.INF
Si9P6-35 P22-10 TB10 TB10Si "KSwitched AC (H)82 AC (N) TB1POWER OR P6-36 P22-11 TB10 E3T4P5-1A2 .341 P3(2 T82 P3-0Cal 8LP5-4AC (N) f*OF*OPERATE* RESETPart of Console Key Switch (TB1 0SIAC (N)Exterral ScramNOAC (N)0- -- 9X6-7l_______ Switched AC (H) f5BFtcFigr 0. Reco prt 0cft- A Fud


.IAttachment 3IN 98-14April20, 1998 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to98-13 Post-Refueling Outage Reactor 4120/98 All holders of operating licensesPressure Vessel Leak TestingBefore Core Criticalityfor nuclear power reactors exceptthose that have permanentlyceased operations and havecertified that fuel has beenpermanently removed from thereactor vessel98-129&-1 1Licensees' ResponsibilitiesRegarding Reporting and Follow-upRequirements for Nuclear-PoweredPacemakersCracking of Reactor VesselInternal Baffle Former Boltsin Foreign Plants4/3/983/25/98All U.S. Nuclear RegulatoryCommission nuclear pacemakerlicenseesAll holders of operating licensingfor pressurized-water reactors(PWRs) except those who haveceased operation and havecertified that fuel has beenpermanently removed from thereactor vessel.95-52, Supp. 1 Fire Endurance Test Resultsfor Electrical Raceway FireBarrier Systems ConstructedFrom 3M Company Interam-ire Barrier Materials3/17/98All holders of operatinglicenses for nuclear powerreactors except those whohave permanently ceasedoperation and have certified thatfuel has been permanentlyremoved from the reactor vessel.98-1098-09Probable MisadministrationsOccurring During IntravascularBrachytherapy With TheNovoste Beta-Cath SystemCollapse Of An Isocam IIDual-Headed NuclearMedicine Gamma Camera3/9/983/5/98All Medical LicenseesAll Medical LicenseesOL = Operating LicenseCP = Construction Permit
To receive a copy of this document, indicate in the box C=Copy wlo attachment/endosure


* KIN ?-14April 20, 1998 depressed, even if a scram contact opened in the other parallel path. The switches shouldhave been wired in series. The licensee cannot determine when the console was wired thisway, but notes that the console underwent a major upgrade in 1968. The logic diagram, drawnin 1976, which differs from the wiring diagram and the as-wired console, appears to have beenbased on system knowledge of how it should be configured rather than on the actualconfiguration.To correct this situation, the licensee changed the wiring to put the RESET switch in series withthe protective action contacts, physically verified console wiring for scram circuits, identifiedvarious failure modes, and tested the console for proper operation.DiscussionThe circumstances described above demonstrate the importance of controlling modifications,ensuring that all of the consequences of a modification are carefully considered, and ensuringthat design features in the scram circuitry perform as designed. Careful reviews ofmodifications through the safety review process can be an effective method to help to ensurethat unintended deleterious effects from modifications do not occur. The identification of safetysystem design features could lead to surveillances or tests that could prevent the occurrence ofsimilar problems. The staff noted that many licensees contacted the NRC to discuss the resultsof testing performed on consoles because of the information placed on the TRTR listed serverby OSU.This information notice requires no specific action or written response. If you have anyquestions about the information in this notice, please contact the technical contact listed below.orig /sfd by D. B. MatthewsFORJack Roe, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contact: Alexander Adams, Jr., NRR301-415-1127E-mail: axa~nrc.govAttachments:1. Figure 1, OReactor Operate Circuit, As-Designed'2. Figure 2, uReactor Operate Circuit -As Found"3. List of Recently Issued NRC Information NoticesDOCUMENT NAME: G:WVERN\OSUSCRAM.INF Tech Editor concurred on 3/26198To receive a copy of this document indicate In the box C=Copy wlo attachmentenclosure E=Copy with attachmentlenclosure N = No copyOFFICE PDND (A)D:PDND I C:PECB Il (A)D:DRPM Il NAME AAdams* MMendonca* JStolz* JRoe*lDATE _ 03/30/98 03/30/98 04106198 j 04/13/98OFFICIAL RECORD COPY
E=Copy with attachment/enclosure


-- INbe14April 20, 1998 depressed, even if a scram contact opened in the other parallel path. The switches shouldhave been wired in series. The licensee cannot determine when the console was wired thisway, but notes that the console underwent a major upgrade in 1968. The logic diagram, drawnin 1976, which differs from the wiring diagram and the as-wired console, appears to have beenbased on system knowledge of how it should be configured rather than on the actualconfiguration.To correct this situation, the licensee changed the wiring to put the RESET switch in series withthe protective action contacts, physically verified console wiring for scram circuits,.identifiedvarious failure modes, and tested the console for proper operation.DiscussionThe circumstances described above demonstrate the importance of controlling modifications,ensuring that all of the consequences of a modification are carefully considered, and ensuringthat design features in the scram circuitry perform as designed. Careful reviews ofmodifications through the safety review process can be an effective method to help to ensurethat unintended deleterious effects from modifications do not occur. The identification of safetysystem design features could lead to surveillances or tests that could prevent the occurrence ofsimilar problems. The staff noted that many licensees contacted the NRC to discuss the resultsof testing performed on consoles because of the information placed on the TRTR listed serverbyOSU.This information notice requires no specific action or written response. If you have anyquestions about the information in this notice, please contact the technical contact listed below.Jack Roe, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contact: Alexander Adams, Jr., NRR301-415-1127E-mail: axa@nrc.govAttachments:1. Figure 1, uReactor Operate Circuit, As-Designed"2. Figure 2, "Reactor Operate Circuit -As Found"3. List of Recently Issued NRC Information NoticesDOCUMENT NAME: G:WVERNOSUSCRAM.INF Tech Editor concurred on 3/26198To receive a copy of this document, indicate in the box C=Copy wlo attachmentlenclosure E=Copy with attachmentenclosure N = NlcopyI OFFICE PDND I (A)D:PDND l C:PECB I (A)D:DRPNAME AAdams* MMendonca* JStoz* JRoe*l DATE 03/30/98 03/30/98 04/06/98 04/13/98OFFICIAL RECORD COPY
N = No copy OFFICE PDND I l (A)D:PDND


IN' XX .K ApexL 1998 (this simulated a switch failure). In this case, the failure of a single switch could preve anindividual scram signal but would have not disabled all scrams. The licensee then ecked thewiring diagrams for the console and discovered that the wiring of the console moed thewiring diagrams. The RESET switches were wired in parallel with the normall y-losed scramcontacts. This wiring maintained power to the magnets through one paralle ath if the switchwas depressed, even if a scram contact opened in the other parallel pathThe switches shouldhave been wired in series. The licensee cannot determine when the sole was wired thisway, but notes that the console underwent a major upgrade in 1968. e logic diagram, drawnin 1976, which differs from the wiring diagram and the as-wired co sole, appears to have beenbased on system knowledge of how i should be configured rat r than on the actualconfiguration.To correct this situation, the licensee changed the wiring put the RESET switch in series withthe protective action contacts, physically verified conso wiring for scram circuits, identifiedvarious failure modes, and tested the console for probr operation.DiscussionThe circumstances described above demon ate the importance of controlling modifications,ensuring that all of the consequences of a odification are carefully considered, and ensuringthat design features in the scram circuit perform as designed. Careful reviews ofmodifications through the safety revie process can be an effective method to help to ensurethat unintended deleterious effects f m modifications do not occur. The Identification of safetysystem design features could lead o surveillances or tests that could prevent the occurrence ofsimilar problems. The staff note that many licensees contacted the NRC to discuss the resultsof testing performed on consols because of the information placed on the TRTR listed serverby OSU.This information notice r uires no specific action or written response. If you have anyquestions about the inf ation in this notice, please contact the technical contact listed below.Jack Roe, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical c ctac: Alexander Adams, Jr., NRR301-415-1127E-mail: axaenrc.govAttac ent: List of Recently Issued NRC Information NoticesDT e MENT NAME: G:WVERN\OSUSCRAM.INFTo receive a copy f this document. indicate In the box C=Copy w/o attachmeE=Copy with coOFFICE PDND I _ (A)D:PDND l C:PE'CB (A)D:DR hl1 INAME AAdams* MMendonca* iQStolz JRoe JkDATE 03/30198 03/30/98 g 4 /j3198OFFICIAL RECORD COPY a-) .
l l C:PECB (A)D:DRPM


IN'- XX_ ApiV..x, 1998 switch failure). The licensee then checked the wiring diagrams for the console and discoveredthat the wiring of the console matched the wiring diagrams. In this case, the failure of a singleswitch could prevent an individual scram signal but would have not disabled all scrams. TheRESET switches were wired in parallel with the normally closed scram contacts. This wiringmaintained power to the magnets through one parallel path if the switch was depressed, even ifa scram contact opened in the other parallel path. The switches should have been wired inseries. The licensee cannot determine when the console was wired this way, but notes that theconsole underwent a major upgrade in 1968. The logic diagram, drawn in 1976, which differsfrom the wiring diagram and the as-wired console, appears to have been based on systemknowledge of how it should be configured rather than on the actual configuration.To correct this situation, the licensee changed the wiring to put the RESET switch in series withthe protective action contacts, physically verified console wiring for scram circuits, identifiedvarious failure modes, and tested the console for proper operation.DiscussionThe circumstances described above demonstrate the Importance of controlling modifications,ensuring that all of the consequences of a modification are carefully considered, and ensuringthat design features in the scram circuitry perform as designed. Careful reviews ofmodifications through the safety review process can be an effective method to help to ensurethat unintended deleterious effects from modifications do not occur. The identification of safetysystem design features could lead to surveillances or tests that could prevent the occurrence ofsimilar problems.This information notice requires no specific action or written response. If you have anyquestions about the information in this notice, please contact the technical contact listed below.Jack Roe, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contact: Alexander Adams, Jr., NRR301-415-1127E-mail: axa@nrc.govAttachment: List of Recently Issued NRC Information NoticesDOCUMENT NAME: G:WVERN\OSUSCRAM.INFTo receive a copy of this document, indicate in the box C=Copy wlo attachment/endosure E=Copy with attachment/enclosure N = No copyOFFICE PDND I l (A)D:PDND l l C:PECB (A)D:DRPM IlNAME AAdams OA l MMendonca L4/) T JStolz JRoeDATE 1 031/)/98 l 0313)198 1 03/ /98 7 03/ /98OFFICIAL RECORD COPY
Il NAME AAdams OA l MMendonca


}}
L4/) T JStolz JRoe DATE 1 031/)/98 l 0313)198 1 03/ /98 7 03/ /98 OFFICIAL RECORD COPY}}


{{Information notice-Nav}}
{{Information notice-Nav}}

Revision as of 14:11, 31 August 2018

Undocumented Changes to Non-Power Reactor Safety System Wiring
ML031050184
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, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant  Entergy icon.png
Issue date: 04/20/1998
From: Roe J W
Office of Nuclear Reactor Regulation
To:
References
IN-98-014, NUDOCS 9804150188
Download: ML031050184 (10)
v • d • e


UNITED STATES NUCLEAR REGULATORY

COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555-0001 April 20, 1998 NRC INFORMATION

NOTICE 98-14: UNDOCUMENTED

CHANGES TO NON-POWER REACTOR SAFETY SYSTEM WIRING

Addressees

All holders of operating

licenses or construction

permits for test and research reactors.

Purpose

The U.S. Nuclear Regulatory

Commission (NRC) is issuing this information

notice to inform addressees

of undocumented

modifications

that have occurred in the scram system wiring of two research reactors.

In the first case, the modification

in conjunction

with a switch failure resulted in the reactor being operated for a short time without any technical

specification (TS)required scrams. In the second case, because of a modification, a switch failure could have resulted in a TS required scram being disabled.

It is expected that recipients

will review the information

for applicability

to their facilities

and consider action, as appropriate, to avoid similar problems.

However, suggestions

contained

in this information

notice are not NRC requirements;

therefore, no specific action or written response is required.Description

of Circumstances

Oregon State Universty On the morning of February 17, 1998, the TRIGA non-power

reactor at Oregon State University (OSU) had completed

a routine 14-minute

run at 15 watts of power to perform core excess reactivity

measurements.

An attempt was made to manually scram the reactor at the end of the run using the scram button. When the manual scram button did not work, the operators

next step was to turn off power to the scram circuit using the reactor's

three-position

key switch.This switch-1s

OFF, OPERATE, and RESET positions

with a spring return between the RESET and OPERATE positions.

As the operator touched the switch, the switch moved from a position between OPERATE and RESET to the OPERATE position.

The operator then tried the manual scram button again and this time it worked.The licensee determined

that a buildup of dirt prevented

the three-position

switch from returning to the OPERATE position.

When the switch is in the RESET position, the scram bus is disabled.

This switch dates to 1967 when the original console was installed.

The switch operated properly during preoperational

testing before startup.Upon further investigation, the licensee discovered

that the wiring of the scram circuit was different

from the wiring shown in the Instrument

Maintenance

Manual provided by the reactor vndr. Fgure I shows part of the circuitry

as designed.

If the key switch is in the OPERATE D 04151-'i ureg 1D s4 ows~g- lt;)X

K>IN 98-14 April 20, 1998 position, ac power is supplied from terminal block one, terminal number four (TBI -4) through TBI-9, to TB2-3, the A3 and Al contacts of the three-position

switch, and then the console power switch. This allows transformer

four (T4) to power the rod magnets. When the key is turned to RESET, this circuit is opened and the magnet current is cut off. This prevents rod withdrawal

if the rods are down, or causes the rods to drop if they are up. This design feature prevents a single failure of the three-position

switch from disabling

the scram circuits.

In the RESET position, power is supplied to the scram reset relays (K19, K20, and K24), which reset the scram relays (only one scram relay, K12, is shown). If the key switch sticks in the RESET position, the scram relay will continued

to be energized

by the reset relay even if a scram signal occurs. This is not a problem because the power would already be cut off to the magnets.Figure 2 shows the wiring as found in the OSU console. The wiring that was between TB1-9 and TB2-3 in the "as designed" circuit was between TBI-9 and TBIO-10 in the OSU console.As a result, there is power to the magnets when the switch is in the RESET or OPERATE position.The licensee concluded

that the location of the jumper was probably modified during initial installation

of the reactor console in 1967. This modification

was probably done to provide power to the *B deck 3 on the three-position

switch to power REACTOR ON lights.The licensee took a number of corrective

actions. The three-position

switch was removed, cleaned, relubricated, and reinstalled

in the console. The reactor console wiring was restored to its as-designed

condition.

The wiring in the scram circuitry

and in other non-scram-related

circuits was checked physically

and electronically

to demonstrate

that the wiring in the console is as designed.

The reactor startup procedure

was rewritten

to test that the magnet power is cut off when the three-position

switch is placed in the RESET position.

The reactor console was subject to routine startup checks and the semiannual

console check procedure.

The reactor vendor was contacted

to obtain checkout procedures

to confirm that all suggested surveillances

are done before reactor operation.

Texas A&M Universiy OSU quickly placed information

about the failure to scram on the Organization

of Test, Researth and Training Reactors (TRTR) list server. As a result, the staff at the Texas A&M University

N&clear Science Center checked the logic diagrams for its TRIGA research reactor and determined

that its reactor could not fail to scram. The Texas A&M console differs from the one at OSU in that there is no master reset equivalence

to the three-position

switch. Three of the scrams have push-button

spring-returned

switches that clear the locked-in

alarm on the console and allow the scram relay coil to be reenergized

if the signal is clear.The licensee also tested the circuit and determined

that each of the three scrams associated

with these switches could be defeated by holding its switch down in the RESET position (this simulated

a switch failure).

In this case, the failure of a single switch could prevent an individual

scram signal but would have not disabled all scrams. The licensee then checked the wiring diagrams for the console and discovered

that the wiring of the console matched the wiring diagrams.

The RESET switches were wired in parallel with the normally closed scram contacts.This wiring maintained

power to the magnets through one parallel path if the switch was

IN 9S*14 April 20, 1998 depressed, even if a scram contact opened in the other parallel path. The switches should have been wired in series. The licensee cannot determine

when the console was wired this way, but notes that the console underwent

a major upgrade in 1968. The logic diagram, drawn in 1976, which differs from the wiring diagram and the as-wired console, appears to have been based on system knowledge

of how it should be configured

rather than on the actual configuration.

To correct this situation, the licensee changed the wiring to put the RESET switch in series with the protective

action contacts, physically

verified console wiring for scram circuits, identified

various failure modes, and tested the console for proper operation.

Discussion

The circumstances

described

above demonstrate

the importance

of controlling

modifications, ensuring that all of the consequences

of a modification

are carefully

considered, and ensuring that design features in the scram circuitry

perform as designed.

Careful reviews of modifications

through the safety review process can be an effective

method to help to ensure that unintended

deleterious

effects from modifications

do not occur. The identification

of safety system design features could lead to surveillances

or tests that could prevent the occurrence

of similar problems.

The staff noted that many licensees

contacted

the NRC to discuss the results of testing performed

on consoles because of the information

placed on the TRTR listed server by OSU.This information

notice requires no specific action or written response.

If you have any questions

about the information

in this notice, please contact the technical

contact listed below.Jack Roe, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contact: Alexander

Adams, Jr., NRR 301-415-1127.E-mail: axa@nrc.gov

Attachments:

1. Figure 1, *Reactor Operate Circuit, As-Designed" 2. Figure 2, Reactor Operate Circuit -As Found" 3. List of Recently Issued NRC Information

Notices-L

vD C Em DOCUMENT NAME: G:WVERN\OSUSCRAM.INF

Tech Editor concurred

on 3126/98 To receive a copy of this document, indicate in the box C=Copy wlo attachmentlenclosure

E=Copy with attachmentfenclosure

N = NIcopy OFFICE PDND (A)D:PDND

C:PECB (A)D:DRPIV\S

A NAME AAdams* MMendonca*

JStolz* JRoe*[DATE 03/30198 03/30/98 04/06/98 04/13/98 5'OFFICIAL RECORD COPY

P6-3 5 P22-1 0 TB10 Switched AC (H)T P2 f6 2 T T1 Bi B36P22-l1 T910 4 T4 50 Operate Permissive

Jumper 1 3 A .34P3-21 TB2 1 4TB` P3-202 CBB1l A4 >3 P5-4 AC (N) *OFF 0J5) *OPERATE (*RESET Part of Console Key Switch TBl 0 dAC (N)External Scram AC (N)-. (Kl12 K19 K20 K24 Kl2 l H tK1 6-7 'Switched AC (H)Fiaure I. Reactor OnprAt0 Circiuit.

Aq-dpeinnadr

..I-- -..--. -V-- --- -..-- .-, --- --- .U.-

Si9 P6-35 P22-10 TB10 TB10 Si "KSwitched

AC (H)82 AC (N) TB1 POWER OR P6-36 P22-11 TB10 E3 T4 P5-1 A2 .341 P3(2 T82 P3-0 Cal 8L P5-4 AC (N) f*OF*OPERATE* RESET Part of Console Key Switch (TB1 0 SIAC (N)Exterral Scram NO AC (N)0- -- 9X6-7 l_______ Switched AC (H) f5B Ftc Figr 0. Reco prt 0cft- A Fud

.I Attachment

3 IN 98-14 April20, 1998 LIST OF RECENTLY ISSUED NRC INFORMATION

NOTICES Information

Date of Notice No. Subject Issuance Issued to 98-13 Post-Refueling

Outage Reactor 4120/98 All holders of operating

licenses Pressure Vessel Leak Testing Before Core Criticality

for nuclear power reactors except those that have permanently

ceased operations

and have certified

that fuel has been permanently

removed from the reactor vessel 98-12 9&-1 1 Licensees'

Responsibilities

Regarding

Reporting

and Follow-up Requirements

for Nuclear-Powered

Pacemakers

Cracking of Reactor Vessel Internal Baffle Former Bolts in Foreign Plants 4/3/98 3/25/98 All U.S. Nuclear Regulatory

Commission

nuclear pacemaker licensees All holders of operating

licensing for pressurized-water

reactors (PWRs) except those who have ceased operation

and have certified

that fuel has been permanently

removed from the reactor vessel.95-52, Supp. 1 Fire Endurance

Test Results for Electrical

Raceway Fire Barrier Systems Constructed

From 3M Company Interam-ire Barrier Materials 3/17/98 All holders of operating licenses for nuclear power reactors except those who have permanently

ceased operation

and have certified

that fuel has been permanently

removed from the reactor vessel.98-10 98-09 Probable Misadministrations

Occurring

During Intravascular

Brachytherapy

With The Novoste Beta-Cath

System Collapse Of An Isocam II Dual-Headed

Nuclear Medicine Gamma Camera 3/9/98 3/5/98 All Medical Licensees All Medical Licensees OL = Operating

License CP = Construction

Permit

  • KIN ?-14 April 20, 1998 depressed, even if a scram contact opened in the other parallel path. The switches should have been wired in series. The licensee cannot determine

when the console was wired this way, but notes that the console underwent

a major upgrade in 1968. The logic diagram, drawn in 1976, which differs from the wiring diagram and the as-wired console, appears to have been based on system knowledge

of how it should be configured

rather than on the actual configuration.

To correct this situation, the licensee changed the wiring to put the RESET switch in series with the protective

action contacts, physically

verified console wiring for scram circuits, identified

various failure modes, and tested the console for proper operation.

Discussion

The circumstances

described

above demonstrate

the importance

of controlling

modifications, ensuring that all of the consequences

of a modification

are carefully

considered, and ensuring that design features in the scram circuitry

perform as designed.

Careful reviews of modifications

through the safety review process can be an effective

method to help to ensure that unintended

deleterious

effects from modifications

do not occur. The identification

of safety system design features could lead to surveillances

or tests that could prevent the occurrence

of similar problems.

The staff noted that many licensees

contacted

the NRC to discuss the results of testing performed

on consoles because of the information

placed on the TRTR listed server by OSU.This information

notice requires no specific action or written response.

If you have any questions

about the information

in this notice, please contact the technical

contact listed below.orig /sfd by D. B. Matthews FOR Jack Roe, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contact: Alexander

Adams, Jr., NRR 301-415-1127 E-mail: axa~nrc.gov

Attachments:

1. Figure 1, OReactor Operate Circuit, As-Designed'

2. Figure 2, uReactor Operate Circuit -As Found" 3. List of Recently Issued NRC Information

Notices DOCUMENT NAME: G:WVERN\OSUSCRAM.INF

Tech Editor concurred

on 3/26198 To receive a copy of this document indicate In the box C=Copy wlo attachmentenclosure

E=Copy with attachmentlenclosure

N = No copy OFFICE PDND (A)D:PDND

I C:PECB Il (A)D:DRPM

Il NAME AAdams* MMendonca*

JStolz* JRoe*lDATE _ 03/30/98 03/30/98 04106198 j 04/13/98 OFFICIAL RECORD COPY

-- INbe14 April 20, 1998 depressed, even if a scram contact opened in the other parallel path. The switches should have been wired in series. The licensee cannot determine

when the console was wired this way, but notes that the console underwent

a major upgrade in 1968. The logic diagram, drawn in 1976, which differs from the wiring diagram and the as-wired console, appears to have been based on system knowledge

of how it should be configured

rather than on the actual configuration.

To correct this situation, the licensee changed the wiring to put the RESET switch in series with the protective

action contacts, physically

verified console wiring for scram circuits,.identified

various failure modes, and tested the console for proper operation.

Discussion

The circumstances

described

above demonstrate

the importance

of controlling

modifications, ensuring that all of the consequences

of a modification

are carefully

considered, and ensuring that design features in the scram circuitry

perform as designed.

Careful reviews of modifications

through the safety review process can be an effective

method to help to ensure that unintended

deleterious

effects from modifications

do not occur. The identification

of safety system design features could lead to surveillances

or tests that could prevent the occurrence

of similar problems.

The staff noted that many licensees

contacted

the NRC to discuss the results of testing performed

on consoles because of the information

placed on the TRTR listed server byOSU.This information

notice requires no specific action or written response.

If you have any questions

about the information

in this notice, please contact the technical

contact listed below.Jack Roe, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contact: Alexander

Adams, Jr., NRR 301-415-1127 E-mail: axa@nrc.gov

Attachments:

1. Figure 1, uReactor Operate Circuit, As-Designed" 2. Figure 2, "Reactor Operate Circuit -As Found" 3. List of Recently Issued NRC Information

Notices DOCUMENT NAME: G:WVERNOSUSCRAM.INF

Tech Editor concurred

on 3/26198 To receive a copy of this document, indicate in the box C=Copy wlo attachmentlenclosure

E=Copy with attachmentenclosure

N = Nlcopy I OFFICE PDND I (A)D:PDND

l C:PECB I (A)D:DRP NAME AAdams* MMendonca*

JStoz* JRoe*l DATE 03/30/98 03/30/98 04/06/98 04/13/98 OFFICIAL RECORD COPY

IN' XX .K ApexL 1998 (this simulated

a switch failure).

In this case, the failure of a single switch could preve an individual

scram signal but would have not disabled all scrams. The licensee then ecked the wiring diagrams for the console and discovered

that the wiring of the console moed the wiring diagrams.

The RESET switches were wired in parallel with the normall y-losed scram contacts.

This wiring maintained

power to the magnets through one paralle ath if the switch was depressed, even if a scram contact opened in the other parallel pathThe switches should have been wired in series. The licensee cannot determine

when the sole was wired this way, but notes that the console underwent

a major upgrade in 1968. e logic diagram, drawn in 1976, which differs from the wiring diagram and the as-wired co sole, appears to have been based on system knowledge

of how i should be configured

rat r than on the actual configuration.

To correct this situation, the licensee changed the wiring put the RESET switch in series with the protective

action contacts, physically

verified conso wiring for scram circuits, identified

various failure modes, and tested the console for probr operation.

Discussion

The circumstances

described

above demon ate the importance

of controlling

modifications, ensuring that all of the consequences

of a odification

are carefully

considered, and ensuring that design features in the scram circuit perform as designed.

Careful reviews of modifications

through the safety revie process can be an effective

method to help to ensure that unintended

deleterious

effects f m modifications

do not occur. The Identification

of safety system design features could lead o surveillances

or tests that could prevent the occurrence

of similar problems.

The staff note that many licensees

contacted

the NRC to discuss the results of testing performed

on consols because of the information

placed on the TRTR listed server by OSU.This information

notice r uires no specific action or written response.

If you have any questions

about the inf ation in this notice, please contact the technical

contact listed below.Jack Roe, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

c ctac: Alexander

Adams, Jr., NRR 301-415-1127 E-mail: axaenrc.gov

Attac ent: List of Recently Issued NRC Information

Notices DT e MENT NAME: G:WVERN\OSUSCRAM.INF

To receive a copy f this document.

indicate In the box C=Copy w/o attachmeE=Copy

with co OFFICE PDND I _ (A)D:PDND

l C:PE'CB (A)D:DR hl1 I NAME AAdams* MMendonca*

iQStolz JRoe Jk DATE 03/30198 03/30/98 g 4 /j3198 OFFICIAL RECORD COPY a-) .

IN'- XX_ ApiV..x, 1998 switch failure).

The licensee then checked the wiring diagrams for the console and discovered

that the wiring of the console matched the wiring diagrams.

In this case, the failure of a single switch could prevent an individual

scram signal but would have not disabled all scrams. The RESET switches were wired in parallel with the normally closed scram contacts.

This wiring maintained

power to the magnets through one parallel path if the switch was depressed, even if a scram contact opened in the other parallel path. The switches should have been wired in series. The licensee cannot determine

when the console was wired this way, but notes that the console underwent

a major upgrade in 1968. The logic diagram, drawn in 1976, which differs from the wiring diagram and the as-wired console, appears to have been based on system knowledge

of how it should be configured

rather than on the actual configuration.

To correct this situation, the licensee changed the wiring to put the RESET switch in series with the protective

action contacts, physically

verified console wiring for scram circuits, identified

various failure modes, and tested the console for proper operation.

Discussion

The circumstances

described

above demonstrate

the Importance

of controlling

modifications, ensuring that all of the consequences

of a modification

are carefully

considered, and ensuring that design features in the scram circuitry

perform as designed.

Careful reviews of modifications

through the safety review process can be an effective

method to help to ensure that unintended

deleterious

effects from modifications

do not occur. The identification

of safety system design features could lead to surveillances

or tests that could prevent the occurrence

of similar problems.This information

notice requires no specific action or written response.

If you have any questions

about the information

in this notice, please contact the technical

contact listed below.Jack Roe, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contact: Alexander

Adams, Jr., NRR 301-415-1127 E-mail: axa@nrc.gov

Attachment:

List of Recently Issued NRC Information

Notices DOCUMENT NAME: G:WVERN\OSUSCRAM.INF

To receive a copy of this document, indicate in the box C=Copy wlo attachment/endosure

E=Copy with attachment/enclosure

N = No copy OFFICE PDND I l (A)D:PDND

l l C:PECB (A)D:DRPM

Il NAME AAdams OA l MMendonca

L4/) T JStolz JRoe DATE 1 031/)/98 l 0313)198 1 03/ /98 7 03/ /98 OFFICIAL RECORD COPY


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