ML090120669: Difference between revisions

From kanterella
Jump to navigation Jump to search
(Created page by program invented by StriderTol)
(StriderTol Bot change)
 
(2 intermediate revisions by the same user not shown)
Line 3: Line 3:
| issue date = 01/29/2009
| issue date = 01/29/2009
| title = Use of Containment Atmosphere Gaseous Radioactivity Monitors as Reactor Coolant System Leakage Detection Equipment at Nuclear Power Reactors
| title = Use of Containment Atmosphere Gaseous Radioactivity Monitors as Reactor Coolant System Leakage Detection Equipment at Nuclear Power Reactors
| author name = McGinty T J
| author name = Mcginty T
| author affiliation = NRC/NRR/DPR
| author affiliation = NRC/NRR/DPR
| addressee name =  
| addressee name =  
Line 17: Line 17:


=Text=
=Text=
{{#Wiki_filter:UNITED STATES  NUCLEAR REGULATORY COMMISSION  
{{#Wiki_filter:UNITED STATES  
  OFFICE OF NUCLEAR REACTOR REGULATION  
   
  WASHINGTON, DC 20555-0001  
NUCLEAR REGULATORY COMMISSION  
  January 29, 2009
   
  NRC REGULATORY I
OFFICE OF NUCLEAR REACTOR REGULATION  
SSUE SUMMARY 2009-02  
   
WASHINGTON, DC 20555-0001  
January 29, 2009  
NRC REGULATORY ISSUE SUMMARY 2009-02  
USE OF CONTAINMENT ATMOSPHERE GASEOUS RADIOACTIVITY  
USE OF CONTAINMENT ATMOSPHERE GASEOUS RADIOACTIVITY  
MONITORS AS REACTOR COOLAN
MONITORS AS REACTOR COOLANT SYSTEM LEAKAGE DETECTION  
T SYSTEM LEAKAGE DETECTION  
EQUIPMENT AT NUCLEAR POWER REACTORS  
EQUIPMENT AT NUCLEAR
   
POWER REACTORS  
ADDRESSEES  
  ADDRESSEES
       
        All holders of operating licenses for nuclear power reactors except those who have permanently ceased operations and have certified that fuel has been permanently removed from the reactor  
All holders of operating licenses for nuclear power reactors except those who have permanently  
vessel.  All current and potential applicants for a combined license, manufacturing license, standard  
ceased operations and have certified that fuel has been permanently removed from the reactor  
vessel.  
   
All current and potential applicants for a combined license, manufacturing license, standard  
design certification, or standard design approval for a nuclear power plant under the provisions  
design certification, or standard design approval for a nuclear power plant under the provisions  
of Title 10 of the Code of Federal Regulations, Part 52 (10 CFR), "Licenses, Certifications, and  
of Title 10 of the Code of Federal Regulations, Part 52 (10 CFR), Licenses, Certifications, and  
 
Approvals for Nuclear Power Plants.  
Approvals for Nuclear Power Plants".  
   
  All applicants for nuclear power plant construction permits and operating licenses under the provisions of 10 CFR Part 50, "Domestic Licensing of Production and Utilization Facilities."
All applicants for nuclear power plant construction permits and operating licenses under the  
  INTENT  The U.S. Nuclear Regulatory Commission (NRC) is issuing this regulatory issue summary (RIS) to communicate the NRC plan to address the situation created when some containment  
provisions of 10 CFR Part 50, Domestic Licensing of Production and Utilization Facilities.  
   
INTENT  
   
The U.S. Nuclear Regulatory Commission (NRC) is issuing this regulatory issue summary (RIS)  
to communicate the NRC plan to address the situation created when some containment  
atmosphere gaseous radioactivity monitors are unable to meet technical specification (TS)  
atmosphere gaseous radioactivity monitors are unable to meet technical specification (TS)  
requirements.  The plan consists of integrating a streamlined license amendment process with  
requirements.  The plan consists of integrating a streamlined license amendment process with  
the use of enforcement discretion, where appropriate.  This RIS requires no action or written response on the part of an addressee.  
the use of enforcement discretion, where appropriate.  This RIS requires no action or written  
  BACKGROUND INFORMATION
response on the part of an addressee.  
  In order to meet General Design Criterion 30, "Quality of reactor coolant pressure boundary," of Appendix A to 10 CFR Part 50,  licensees typically include RCS leakage detection equipment in their plant designs because the equipment can be used to detect reactor coolant pressure  
   
 
BACKGROUND INFORMATION  
In order to meet General Design Criterion 30, "Quality of reactor coolant pressure boundary," of  
Appendix A to 10 CFR Part 50,  licensees typically include RCS leakage detection equipment in  
their plant designs because the equipment can be used to detect reactor coolant pressure  
boundary (RCPB) leakage.  A typical RCS leakage detection system consists of a combination  
boundary (RCPB) leakage.  A typical RCS leakage detection system consists of a combination  
of the following:   
of the following:   
*
a containment atmosphere particulate radioactivity monitoring system
*
a containment atmosphere gaseous radioactivity monitoring system 
*
containment sump-level and sump-pump instrumentation 
*
containment cooler condensate monitoring instrumentation
ML090120669


* a containment atmosphere particulate radioactivity monitoring system
* a containment atmosphere gaseous radioactivity monitoring system 
* containment sump-level and sump-pump instrumentation 
* containment cooler condensate monitoring instrumentation
ML090120669 
RIS 2009-02  
RIS 2009-02  
Page 2 of 5  Containment atmosphere gaseous radioactivity monitoring systems measure RCS leakage indirectly by detecting airborne radioactivity released from RCS leakage.  Response time is the  
Page 2 of 5  
   
Containment atmosphere gaseous radioactivity monitoring systems measure RCS leakage  
indirectly by detecting airborne radioactivity released from RCS leakage.  Response time is the  
length of time required for these monitoring systems to detect a given volume of RCS leakage.   
length of time required for these monitoring systems to detect a given volume of RCS leakage.   
 
Response time is dependant on RCS radioactivity concentration, as well as other variables.  For  
Response time is dependant on RCS radioactivity concentration, as well as other variables.  For a given volume of leakage, with all other variables held constant, a higher RCS radioactivity  
a given volume of leakage, with all other variables held constant, a higher RCS radioactivity  
concentration will yield a shorter response time for these monitoring systems.  The design analyses for the containment atmosphere gaseous radioactivity monitoring systems used in the licensing bases for most plants typically assume a RCS radioactivity concentration  
concentration will yield a shorter response time for these monitoring systems.  The design  
approximately equivalent to 0.1 percent failed fuel in the core.  Improvements in fuel cladding integrity and RCS chemistry controls have significantly reduced RCS radioactivity concentration at most plants.  As a result, the monitors for operating units may have longer response times than they would with 0.1 percent failed fuel in the core because the actual RCS radioactivity concentration is less than it would be with 0.1 percent failed fuel in the core.   
analyses for the containment atmosphere gaseous radioactivity monitoring systems used in the  
 
licensing bases for most plants typically assume a RCS radioactivity concentration  
approximately equivalent to 0.1 percent failed fuel in the core.  Improvements in fuel cladding  
integrity and RCS chemistry controls have significantly reduced RCS radioactivity concentration  
at most plants.  As a result, the monitors for operating units may have longer response times  
than they would with 0.1 percent failed fuel in the core because the actual RCS radioactivity  
concentration is less than it would be with 0.1 percent failed fuel in the core.   
   
   
Most plants have TS Limiting Conditions fo
Most plants have TS Limiting Conditions for Operation requirements for containment  
r Operation requirements for containment atmosphere gaseous radioactivity monitoring systems used as part of RCS leakage detection  
atmosphere gaseous radioactivity monitoring systems used as part of RCS leakage detection  
equipment.  The TS requirements for the monito
equipment.  The TS requirements for the monitoring systems response times are based on the  
ring systems' response times are based on the design analysis that is part of a plant's licensing basis.  If the monitors fail to meet these requirements, the monitors are inoperable. When the monitors are inoperable the licensee is required to take remedial actions as permitted by their TS or to shut down the reactor.  
design analysis that is part of a plants licensing basis.  If the monitors fail to meet these  
 
requirements, the monitors are inoperable. When the monitors are inoperable the licensee is  
required to take remedial actions as permitted by their TS or to shut down the reactor.  
   
   
Information Notice (IN) 2005-24, "Nonconservatism in Leakage Detection Sensitivity" (ADAMS Accession No. ML051780073), communicated the issue created by differences  
Information Notice (IN) 2005-24, Nonconservatism in Leakage Detection Sensitivity  
 
(ADAMS Accession No. ML051780073), communicated the issue created by differences  
between actual and assumed RCS radioactivity concentrations to all licensees.  The purpose of IN 2005-24 was to have licensees review information related to problems with containment  
between actual and assumed RCS radioactivity concentrations to all licensees.  The purpose of  
atmosphere gaseous radioactivity monitors used as part of RCS leakage detection equipment and consider appropriate actions as applicable to their plants.  Information Notices do not  
IN 2005-24 was to have licensees review information related to problems with containment  
atmosphere gaseous radioactivity monitors used as part of RCS leakage detection equipment  
and consider appropriate actions as applicable to their plants.  Information Notices do not  
require any action by licensees.  
require any action by licensees.  
   
   
In September 2008, NRC inspectors at the Diabl
In September 2008, NRC inspectors at the Diablo Canyon Power Plant identified a non-cited  
o Canyon Power Plant identified a non-cited violation for not complying with TS requirements for RCS leakage detection equipment.  In  
violation for not complying with TS requirements for RCS leakage detection equipment.  In  
November 2008, the licensee for the Watts Bar Nuclear Plant and the Sequoyah Nuclear Plant requested exigent license amendments from the NRC after taking remedial actions as permitted by their TS because of a concern that the containment atmosphere gaseous radioactivity monitor channels of the RCS leakage detection system were inoperable.   
November 2008, the licensee for the Watts Bar Nuclear Plant and the Sequoyah Nuclear Plant  
 
requested exigent license amendments from the NRC after taking remedial actions as permitted  
by their TS because of a concern that the containment atmosphere gaseous radioactivity  
monitor channels of the RCS leakage detection system were inoperable.   
   
   
To address the issue, licensees working through the industry-sponsored Technical  
To address the issue, licensees working through the industry-sponsored Technical  
Specifications Task Force (TSTF) have attempted to create generic TS changes, model License Amendment Requests (LARs), model safety evaluations, and model proposed  
Specifications Task Force (TSTF) have attempted to create generic TS changes, model License  
no-significant-hazards consideration determinations using the NRC TS Consolidated Line Item Improvement Process (CLIIP).  See RIS 2000-10, "Consolidated Line Item Improvement Process For Adopting Standard Technical Specifications Changes for Power Reactors
Amendment Requests (LARs), model safety evaluations, and model proposed  
" (ADAMS Accession No. ML003693442) for more information on the NRC CLIIP.  
no-significant-hazards consideration determinations using the NRC TS Consolidated Line Item  
   
Improvement Process (CLIIP).  See RIS 2000-10, Consolidated Line Item Improvement  
 
Process For Adopting Standard Technical Specifications Changes for Power Reactors  
(ADAMS Accession No. ML003693442) for more information on the NRC CLIIP.  
 
RIS 2009-02  
RIS 2009-02  
Page 3 of 5  SUMMARY OF ISSUE
Page 3 of 5  
  Improvements in fuel cladding integrity and RCS chemistry controls result in lower RCS  
   
radioactivity concentrations during operational activities, including situations where there is RCS leakage.  Thus, containment atmosphere gaseous radioactivity monitoring systems which are  
SUMMARY OF ISSUE  
designed on the basis of higher assumed RCS radioactivity concentrations will not provide accurate indication of RCS leakage in the required length of time due to the longer response time of the monitoring system, and must be considered inoperable.  
 
Improvements in fuel cladding integrity and RCS chemistry controls result in lower RCS  
The NRC considers the longer response times of the containment atmosphere gaseous  
radioactivity concentrations during operational activities, including situations where there is RCS  
radioactivity monitors to be of very low safety significance.  The monitors would still be able to detect degradation in the RCPB long before components fail in a manner that would affect plant safety.  Additionally, plants also have multiple diverse and redundant methods available to  
leakage.  Thus, containment atmosphere gaseous radioactivity monitoring systems which are  
designed on the basis of higher assumed RCS radioactivity concentrations will not provide  
accurate indication of RCS leakage in the required length of time due to the longer response  
time of the monitoring system, and must be considered inoperable.  
The NRC considers the longer response times of the containment atmosphere gaseous  
radioactivity monitors to be of very low safety significance.  The monitors would still be able to  
detect degradation in the RCPB long before components fail in a manner that would affect plant  
safety.  Additionally, plants also have multiple diverse and redundant methods available to  
detect RCS leakage and to provide licensees with a means to detect significant RCPB  
detect RCS leakage and to provide licensees with a means to detect significant RCPB  
degradation and to take appropriate action to ensure the continued protection of public health  
degradation and to take appropriate action to ensure the continued protection of public health  
 
and safety.  Finally, nuclear power plants are designed to provide adequate core cooling  
and safety.  Finally, nuclear power plants are designed to provide adequate core cooling following postulated loss-of-coolant accidents up to and including a break equivalent in size to  
following postulated loss-of-coolant accidents up to and including a break equivalent in size to  
the double-ended rupture of the largest pipe in the RCS.  This design feature, coupled with the  
the double-ended rupture of the largest pipe in the RCS.  This design feature, coupled with the  
extremely low likelihood of unstable crack growth resulting in a loss-of-coolant accident, leads  
extremely low likelihood of unstable crack growth resulting in a loss-of-coolant accident, leads  
the NRC to conclude that the risk signifi
the NRC to conclude that the risk significance of this issue is very low.  
cance of this issue is very low.  
   
   
The NRC plans to address the issue of inoperable containment atmosphere gaseous  
The NRC plans to address the issue of inoperable containment atmosphere gaseous  
radioactivity monitoring systems in an integrated fashion by: (i) working with the TSTF to develop revised generic TS for the monitoring system, and facilitating licensee implementation of the revised generic TS through a streamlined license amendment process; and (ii) issuing guidance on NRC's exercise of enforcement  
radioactivity monitoring systems in an integrated fashion by: (i) working with the TSTF to  
discretion involving inoperable containment atmosphere gaseous radioactivity monitoring systems.   
develop revised generic TS for the monitoring system, and facilitating licensee implementation  
  The NRC will review the generic TS changes that the TSTF proposes for pressurized-water  
of the revised generic TS through a streamlined license amendment process; and (ii) issuing  
guidance on NRCs exercise of enforcement discretion involving inoperable containment  
atmosphere gaseous radioactivity monitoring systems.   
   
The NRC will review the generic TS changes that the TSTF proposes for pressurized-water  
reactors (PWRs) and boiling-water reactors (BWRs).  If the generic TS changes are found to be  
reactors (PWRs) and boiling-water reactors (BWRs).  If the generic TS changes are found to be  
acceptable, the NRC will make the generic model  
acceptable, the NRC will make the generic model LARs, model safety evaluations, and model  
LARs, model safety evaluations, and model  
no-significant-hazards consideration determinations available to licensees using the NRC CLIIP.  
no-significant-hazards consideration determinations available to licensees using the NRC CLIIP. Licensees are free to submit LARs for TS changes to address the issue.  If licensees deem further action regarding the issue is unwarranted, they can choose to take no action.  
Licensees are free to submit LARs for TS changes to address the issue.  If licensees deem  
further action regarding the issue is unwarranted, they can choose to take no action.  
On November 14, 2008, the TSTF submitted TSTF-513, Revise Operability Requirements and
Actions for RCS Leakage Instrumentation, to the NRC for review.  TSTF-513 proposes generic
TS changes for PWRs.  The TSTF plans to submit TSTF-514 to the NRC in January 2009. 
TSTF-514 will propose generic TS changes for BWRs.  Licensees are free to submit LARs to
address the issue using TSTF-513 or TSTF-514; or they can propose alternative solutions. 
In certain circumstances involving inoperable containment atmosphere gaseous radioactivity
monitoring systems, enforcement discretion is available.  Specific guidance for this enforcement
discretion is described in EGM-09-001 (ADAMS Accession No. ML090300467) and is available
on the NRCs web site at www.nrc.gov.
   
   
On November 14, 2008, the TSTF submitted TSTF-513, "Revise Operability Requirements and
Actions for RCS Leakage Instrumentation," to the NRC for review.  TSTF-513 proposes generic


TS changes for PWRs.  The TSTF plans to submit TSTF-514 to the NRC in January 2009.  TSTF-514 will propose generic TS changes for BWRs.  Licensees are free to submit LARs to address the issue using TSTF-513 or TSTF-514; or they can propose alternative solutions. 
RIS 2009-02
In certain circumstances involving inoperable containment atmosphere gaseous radioactivity monitoring systems, enforcement discretion is available.  Specific guidance for this enforcement discretion is described in EGM-09-001
Page 4 of 5
(ADAMS Accession No.
ML090300467) and is available
on the NRC's web site at www.nrc.gov
. 
   
   
 
BACKFIT DISCUSSION
RIS 2009-02
   
Page 4 of 5 BACKFIT DISCUSSION
The intent of this RIS is to inform addressees of the NRCs plan to address the failure of  
  The intent of this RIS is to inform addressees of the NRC's plan to address the failure of  
containment atmosphere gaseous radioactivity monitors used as RCS leakage detection  
containment atmosphere gaseous radioactivity monitors used as RCS leakage detection  
equipment to meet TS requirements.  
equipment to meet TS requirements.  
  The staff is not imposing any new positions on licensees.  This RIS is not providing any new
regulatory positions.  This RIS only conveys the NRC's plan to address the issue of RCS leakage detection equipment failing to meet TS requirements because of the difference between actual and assumed RCS radioactivity concentrations.  This RIS requires no action or written response and, therefore, is not a backfit under 10 CFR 50.109, "Backfitting."  Consequently, the staff did not perform a backfit analysis.
   
   
  FEDERAL REGISTER NOTIFICATION
   
  A notice of opportunity for public comment on this RIS was not published in the  
The staff is not imposing any new positions on licensees.  This RIS is not providing any new
Federal Register
regulatory positions.  This RIS only conveys the NRCs plan to address the issue of RCS
because it is informational and pertains to a staff position that does not represent a departure from current regulatory requirements and practice.  However, a public meeting to discuss this  
leakage detection equipment failing to meet TS requirements because of the difference between
actual and assumed RCS radioactivity concentrations.  This RIS requires no action or written
response and, therefore, is not a backfit under 10 CFR 50.109, Backfitting.  Consequently, the
staff did not perform a backfit analysis.
FEDERAL REGISTER NOTIFICATION  
A notice of opportunity for public comment on this RIS was not published in the Federal Register  
because it is informational and pertains to a staff position that does not represent a departure  
from current regulatory requirements and practice.  However, a public meeting to discuss this  
RIS was held on January 8, 2009.  The meeting summary is available under ADAMS Accession  
RIS was held on January 8, 2009.  The meeting summary is available under ADAMS Accession  
No. ML090130583.  The NRC intends to work with industry representatives, members of the  
No. ML090130583.  The NRC intends to work with industry representatives, members of the  
public, and other stakeholders in developing final guidance and in modifying related guidance  
public, and other stakeholders in developing final guidance and in modifying related guidance  
documents.  
documents.  
  CONGRESSIONAL REVIEW ACT
   
  This RIS is not a rule as designated by the Congressional Review Act (5 U.S.C. §§ 801-808) and, therefore, is not subject to the Act.  
CONGRESSIONAL REVIEW ACT  
  PAPERWORK REDUCTION ACT STATEMENT
  This RIS does not contain any information collections and, therefore, is not subject to the requirements of the Paperwork Reduction Act of 1995 (44 U.S.C. 3501, et seq.).  
This RIS is not a rule as designated by the Congressional Review Act (5 U.S.C. §§ 801-808)  
  PUBLIC PROTECTION NOTIFICATION  
and, therefore, is not subject to the Act.  
  The NRC may not conduct or sponsor, and a person is not required to respond to, a request for  
   
information or an information collection requirement unless the requesting document displays a currently valid OMB control number.  
PAPERWORK REDUCTION ACT STATEMENT  
 
This RIS does not contain any information collections and, therefore, is not subject to the  
requirements of the Paperwork Reduction Act of 1995 (44 U.S.C. 3501, et seq.).  
   
PUBLIC PROTECTION NOTIFICATION  
   
The NRC may not conduct or sponsor, and a person is not required to respond to, a request for  
information or an information collection requirement unless the requesting document displays a  
currently valid OMB control number.  
   
   
   
   
 
   
   
 
 
RIS 2009-02  
RIS 2009-02  
Page 5 of 5  CONTACT  Please direct any questions about this matter to the technical contact listed below or to the  
Page 5 of 5  
   
CONTACT  
   
Please direct any questions about this matter to the technical contact listed below or to the  
appropriate Office of Nuclear Reactor Regulation (NRR) project manager.  
appropriate Office of Nuclear Reactor Regulation (NRR) project manager.  
   
   
  /RA by Theodore R. Quay For/  
   
  Timothy J. McGinty, Director  
/RA by Theodore R. Quay For/  
Division of Policy and Rulemaking Office of Nuclear Reactor Regulation  
   
  Technical Contact:  Matthew Hamm, NRR        301-415-1472  
Timothy J. McGinty, Director  
         e-mail:  matthew.hamm@nrc.gov
Division of Policy and Rulemaking  
 
Office of Nuclear Reactor Regulation  
Technical Contact:  Matthew Hamm, NRR  
         301-415-1472  
         e-mail:  matthew.hamm@nrc.gov  
Note: NRC generic communications may be found on the NRC public Web site,  
Note: NRC generic communications may be found on the NRC public Web site,  
http://www.nrc.gov, under Electronic Reading Room/Document Collections.
http://www.nrc.gov, under Electronic Reading Room/Document Collections.  
 
RIS 2009-02  
RIS 2009-02  
Page 5 of 5 CONTACT  Please direct any questions about this matter to the technical contact listed below or to the  
Page 5 of 5  
CONTACT  
   
Please direct any questions about this matter to the technical contact listed below or to the  
appropriate Office of Nuclear Reactor Regulation (NRR) project manager.  
appropriate Office of Nuclear Reactor Regulation (NRR) project manager.  
   
   
  /RA by Theodore R. Quay For/  
   
  Timothy J. McGinty, Director  
/RA by Theodore R. Quay For/  
 
   
Timothy J. McGinty, Director  
Division of Policy and Rulemaking  
Division of Policy and Rulemaking  
Office of Nuclear Reactor Regulation  
Office of Nuclear Reactor Regulation  
  Technical Contact:  Matthew Hamm, NRR        301-415-1472  
e-mail:  matthew.hamm@nrc.gov
  Note: NRC generic communications may be found on the NRC public Web site, http://www.nrc.gov, under Electronic Reading Room/Document Collections.  
Technical Contact:  Matthew Hamm, NRR  
  ADAMS ACCESSION No. ML090120669 OFFICIAL RECORD COPY  
         301-415-1472  
  O FFICE  
e-mail:  matthew.hamm@nrc.gov  
Note: NRC generic communications may be found on the NRC public Web site,  
http://www.nrc.gov, under Electronic Reading Room/Document Collections.  
   
ADAMS ACCESSION No. ML090120669  
OFFICIAL RECORD COPY  
   
OFFICE
   
ITSB:DIRS  
ITSB:DIRS  
   
   
Tech Editor BC:ITSBDIRS
Tech Editor  
D:DIRS PSPB DPR   
BC:ITSBDIRS
D:DIRS  
PSPB DPR  
   
BC:PSPB DPR  
BC:PSPB DPR  
  NAME MHamm via email  
   
RElliott FBrown MCheok for  
NAME  
MHamm  
via email  
RElliott  
FBrown  
MCheok for  
JWilliams  
JWilliams  
SRosenberg  
SRosenberg  
DNelson for  
DNelson for  
  D ATE 12/19/2008  
   
DATE
12/19/2008  
12/15/2008  
12/15/2008  
1/12/2009 1/12/2009  12/30/2008  
1/12/2009  
1/12/2009  
  12/30/2008  
  12/30/2008  
  12/30/2008  
  O FFICE D:DSS D:DORL   
   
RI:DRP:D   
OFFICE
D:DSS  
D:DORL  
   
RI:DRP:D  
   
RII:DRP:D  
RII:DRP:D  
   
   
Line 200: Line 320:
   
   
RIV:DRP:D  
RIV:DRP:D  
  NAME WRuland for JGiitter  
   
DLew via email LWert via  
NAME  
email CPederson  
WRuland  
 
for JGiitter  
via email DChamberlain  
DLew via  
 
email  
LWert via  
email  
CPederson  
via email  
DChamberlain  
via email  
via email  
  D ATE 1/12/2009 12/30/2008  
   
DATE
1/12/2009  
12/30/2008  
1/15/2009
1/14/2009
1/13/2009
1/15/2009  
1/15/2009  
1/14/2009 1/13/2009 1/15/2009  
   
OFFICE   
OFFICE  
D:DCI BC:CHPB DCIP D: DCIP/NRO
   
  OE   
D:DCI  
BC:CHPB  
DCIP  
D: DCIP/NRO
   
OE  
   
OGC (NLO)  
OGC (NLO)  
   
   
OGC (CRA)  
OGC (CRA)  
   
   
NAME MEvans TFrye CHinson for  
NAME  
GTracy DStarkey via email  
MEvans  
BJones NSanchez via email   
TFrye  
CHinson for  
GTracy  
DStarkey  
via email  
BJones  
NSanchez  
via email   
   
   
DATE 1/15/2009 0 1/07/2009  
DATE  
1/15/2009  
01/07/2009  
01/08/2009  
01/08/2009  
1/14/2009    01/27/2009  
1/14/2009  
  1/28/2009  
   01/27/2009  1/28/2009  
OFFICE
PMDA
   
   
OFFICE 
OIS
P MDA 
LA:PGCB  
OIS LA:PGCB PGCB BC: PGCB D:DPR NAME   
PGCB  
LHill GTrussell  
BC: PGCB  
D:DPR  
NAME  
   
LHill  
GTrussell  
CHawes     
CHawes     
SStuchell  
SStuchell  
MMurphy TMcGinty TRQ  
MMurphy  
for   
TMcGinty TRQ  
DATE 01/05/2009  
for  
   
DATE  
01/05/2009  
01/07/2009  
01/07/2009  
  1/28/2009  
  1/28/2009  

Latest revision as of 13:44, 14 January 2025

Use of Containment Atmosphere Gaseous Radioactivity Monitors as Reactor Coolant System Leakage Detection Equipment at Nuclear Power Reactors
ML090120669
Person / Time
Issue date: 01/29/2009
From: Mcginty T
Division of Policy and Rulemaking
To:
Hawes C, NRR/DPR/PGCB, 415-1316
References
RIS-09-002
Download: ML090120669 (6)
v • d • e


See also: RIS 2009-02

Text

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, DC 20555-0001

January 29, 2009

NRC REGULATORY ISSUE SUMMARY 2009-02

USE OF CONTAINMENT ATMOSPHERE GASEOUS RADIOACTIVITY

MONITORS AS REACTOR COOLANT SYSTEM LEAKAGE DETECTION

EQUIPMENT AT NUCLEAR POWER REACTORS

ADDRESSEES

All holders of operating licenses for nuclear power reactors except those who have permanently

ceased operations and have certified that fuel has been permanently removed from the reactor

vessel.

All current and potential applicants for a combined license, manufacturing license, standard

design certification, or standard design approval for a nuclear power plant under the provisions

of Title 10 of the Code of Federal Regulations, Part 52 (10 CFR), Licenses, Certifications, and

Approvals for Nuclear Power Plants.

All applicants for nuclear power plant construction permits and operating licenses under the

provisions of 10 CFR Part 50, Domestic Licensing of Production and Utilization Facilities.

INTENT

The U.S. Nuclear Regulatory Commission (NRC) is issuing this regulatory issue summary (RIS)

to communicate the NRC plan to address the situation created when some containment

atmosphere gaseous radioactivity monitors are unable to meet technical specification (TS)

requirements. The plan consists of integrating a streamlined license amendment process with

the use of enforcement discretion, where appropriate. This RIS requires no action or written

response on the part of an addressee.

BACKGROUND INFORMATION

In order to meet General Design Criterion 30, "Quality of reactor coolant pressure boundary," of

Appendix A to 10 CFR Part 50, licensees typically include RCS leakage detection equipment in

their plant designs because the equipment can be used to detect reactor coolant pressure

boundary (RCPB) leakage. A typical RCS leakage detection system consists of a combination

of the following:

a containment atmosphere particulate radioactivity monitoring system

a containment atmosphere gaseous radioactivity monitoring system

containment sump-level and sump-pump instrumentation

containment cooler condensate monitoring instrumentation

ML090120669

RIS 2009-02

Page 2 of 5

Containment atmosphere gaseous radioactivity monitoring systems measure RCS leakage

indirectly by detecting airborne radioactivity released from RCS leakage. Response time is the

length of time required for these monitoring systems to detect a given volume of RCS leakage.

Response time is dependant on RCS radioactivity concentration, as well as other variables. For

a given volume of leakage, with all other variables held constant, a higher RCS radioactivity

concentration will yield a shorter response time for these monitoring systems. The design

analyses for the containment atmosphere gaseous radioactivity monitoring systems used in the

licensing bases for most plants typically assume a RCS radioactivity concentration

approximately equivalent to 0.1 percent failed fuel in the core. Improvements in fuel cladding

integrity and RCS chemistry controls have significantly reduced RCS radioactivity concentration

at most plants. As a result, the monitors for operating units may have longer response times

than they would with 0.1 percent failed fuel in the core because the actual RCS radioactivity

concentration is less than it would be with 0.1 percent failed fuel in the core.

Most plants have TS Limiting Conditions for Operation requirements for containment

atmosphere gaseous radioactivity monitoring systems used as part of RCS leakage detection

equipment. The TS requirements for the monitoring systems response times are based on the

design analysis that is part of a plants licensing basis. If the monitors fail to meet these

requirements, the monitors are inoperable. When the monitors are inoperable the licensee is

required to take remedial actions as permitted by their TS or to shut down the reactor.

Information Notice (IN) 2005-24, Nonconservatism in Leakage Detection Sensitivity

(ADAMS Accession No. ML051780073), communicated the issue created by differences

between actual and assumed RCS radioactivity concentrations to all licensees. The purpose of

IN 2005-24 was to have licensees review information related to problems with containment

atmosphere gaseous radioactivity monitors used as part of RCS leakage detection equipment

and consider appropriate actions as applicable to their plants. Information Notices do not

require any action by licensees.

In September 2008, NRC inspectors at the Diablo Canyon Power Plant identified a non-cited

violation for not complying with TS requirements for RCS leakage detection equipment. In

November 2008, the licensee for the Watts Bar Nuclear Plant and the Sequoyah Nuclear Plant

requested exigent license amendments from the NRC after taking remedial actions as permitted

by their TS because of a concern that the containment atmosphere gaseous radioactivity

monitor channels of the RCS leakage detection system were inoperable.

To address the issue, licensees working through the industry-sponsored Technical

Specifications Task Force (TSTF) have attempted to create generic TS changes, model License

Amendment Requests (LARs), model safety evaluations, and model proposed

no-significant-hazards consideration determinations using the NRC TS Consolidated Line Item

Improvement Process (CLIIP). See RIS 2000-10, Consolidated Line Item Improvement

Process For Adopting Standard Technical Specifications Changes for Power Reactors

(ADAMS Accession No. ML003693442) for more information on the NRC CLIIP.

RIS 2009-02

Page 3 of 5

SUMMARY OF ISSUE

Improvements in fuel cladding integrity and RCS chemistry controls result in lower RCS

radioactivity concentrations during operational activities, including situations where there is RCS

leakage. Thus, containment atmosphere gaseous radioactivity monitoring systems which are

designed on the basis of higher assumed RCS radioactivity concentrations will not provide

accurate indication of RCS leakage in the required length of time due to the longer response

time of the monitoring system, and must be considered inoperable.

The NRC considers the longer response times of the containment atmosphere gaseous

radioactivity monitors to be of very low safety significance. The monitors would still be able to

detect degradation in the RCPB long before components fail in a manner that would affect plant

safety. Additionally, plants also have multiple diverse and redundant methods available to

detect RCS leakage and to provide licensees with a means to detect significant RCPB

degradation and to take appropriate action to ensure the continued protection of public health

and safety. Finally, nuclear power plants are designed to provide adequate core cooling

following postulated loss-of-coolant accidents up to and including a break equivalent in size to

the double-ended rupture of the largest pipe in the RCS. This design feature, coupled with the

extremely low likelihood of unstable crack growth resulting in a loss-of-coolant accident, leads

the NRC to conclude that the risk significance of this issue is very low.

The NRC plans to address the issue of inoperable containment atmosphere gaseous

radioactivity monitoring systems in an integrated fashion by: (i) working with the TSTF to

develop revised generic TS for the monitoring system, and facilitating licensee implementation

of the revised generic TS through a streamlined license amendment process; and (ii) issuing

guidance on NRCs exercise of enforcement discretion involving inoperable containment

atmosphere gaseous radioactivity monitoring systems.

The NRC will review the generic TS changes that the TSTF proposes for pressurized-water

reactors (PWRs) and boiling-water reactors (BWRs). If the generic TS changes are found to be

acceptable, the NRC will make the generic model LARs, model safety evaluations, and model

no-significant-hazards consideration determinations available to licensees using the NRC CLIIP.

Licensees are free to submit LARs for TS changes to address the issue. If licensees deem

further action regarding the issue is unwarranted, they can choose to take no action.

On November 14, 2008, the TSTF submitted TSTF-513, Revise Operability Requirements and

Actions for RCS Leakage Instrumentation, to the NRC for review. TSTF-513 proposes generic

TS changes for PWRs. The TSTF plans to submit TSTF-514 to the NRC in January 2009.

TSTF-514 will propose generic TS changes for BWRs. Licensees are free to submit LARs to

address the issue using TSTF-513 or TSTF-514; or they can propose alternative solutions.

In certain circumstances involving inoperable containment atmosphere gaseous radioactivity

monitoring systems, enforcement discretion is available. Specific guidance for this enforcement

discretion is described in EGM-09-001 (ADAMS Accession No. ML090300467) and is available

on the NRCs web site at www.nrc.gov.

RIS 2009-02

Page 4 of 5

BACKFIT DISCUSSION

The intent of this RIS is to inform addressees of the NRCs plan to address the failure of

containment atmosphere gaseous radioactivity monitors used as RCS leakage detection

equipment to meet TS requirements.

The staff is not imposing any new positions on licensees. This RIS is not providing any new

regulatory positions. This RIS only conveys the NRCs plan to address the issue of RCS

leakage detection equipment failing to meet TS requirements because of the difference between

actual and assumed RCS radioactivity concentrations. This RIS requires no action or written

response and, therefore, is not a backfit under 10 CFR 50.109, Backfitting. Consequently, the

staff did not perform a backfit analysis.

FEDERAL REGISTER NOTIFICATION

A notice of opportunity for public comment on this RIS was not published in the Federal Register

because it is informational and pertains to a staff position that does not represent a departure

from current regulatory requirements and practice. However, a public meeting to discuss this

RIS was held on January 8, 2009. The meeting summary is available under ADAMS Accession

No. ML090130583. The NRC intends to work with industry representatives, members of the

public, and other stakeholders in developing final guidance and in modifying related guidance

documents.

CONGRESSIONAL REVIEW ACT

This RIS is not a rule as designated by the Congressional Review Act (5 U.S.C. §§ 801-808)

and, therefore, is not subject to the Act.

PAPERWORK REDUCTION ACT STATEMENT

This RIS does not contain any information collections and, therefore, is not subject to the

requirements of the Paperwork Reduction Act of 1995 (44 U.S.C. 3501, et seq.).

PUBLIC PROTECTION NOTIFICATION

The NRC may not conduct or sponsor, and a person is not required to respond to, a request for

information or an information collection requirement unless the requesting document displays a

currently valid OMB control number.

RIS 2009-02

Page 5 of 5

CONTACT

Please direct any questions about this matter to the technical contact listed below or to the

appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

/RA by Theodore R. Quay For/

Timothy J. McGinty, Director

Division of Policy and Rulemaking

Office of Nuclear Reactor Regulation

Technical Contact: Matthew Hamm, NRR

301-415-1472

e-mail: matthew.hamm@nrc.gov

Note: NRC generic communications may be found on the NRC public Web site,

http://www.nrc.gov, under Electronic Reading Room/Document Collections.

RIS 2009-02

Page 5 of 5

CONTACT

Please direct any questions about this matter to the technical contact listed below or to the

appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

/RA by Theodore R. Quay For/

Timothy J. McGinty, Director

Division of Policy and Rulemaking

Office of Nuclear Reactor Regulation

Technical Contact: Matthew Hamm, NRR

301-415-1472

e-mail: matthew.hamm@nrc.gov

Note: NRC generic communications may be found on the NRC public Web site,

http://www.nrc.gov, under Electronic Reading Room/Document Collections.

ADAMS ACCESSION No. ML090120669

OFFICIAL RECORD COPY

OFFICE

ITSB:DIRS

Tech Editor

BC:ITSBDIRS

D:DIRS

PSPB DPR

BC:PSPB DPR

NAME

MHamm

via email

RElliott

FBrown

MCheok for

JWilliams

SRosenberg

DNelson for

DATE

12/19/2008

12/15/2008

1/12/2009

1/12/2009

12/30/2008

12/30/2008

OFFICE

D:DSS

D:DORL

RI:DRP:D

RII:DRP:D

RIII:DRP:D

RIV:DRP:D

NAME

WRuland

for JGiitter

DLew via

email

LWert via

email

CPederson

via email

DChamberlain

via email

DATE

1/12/2009

12/30/2008

1/15/2009

1/14/2009

1/13/2009

1/15/2009

OFFICE

D:DCI

BC:CHPB

DCIP

D: DCIP/NRO

OE

OGC (NLO)

OGC (CRA)

NAME

MEvans

TFrye

CHinson for

GTracy

DStarkey

via email

BJones

NSanchez

via email

DATE

1/15/2009

01/07/2009

01/08/2009

1/14/2009

01/27/2009 1/28/2009

OFFICE

PMDA

OIS

LA:PGCB

PGCB

BC: PGCB

D:DPR

NAME

LHill

GTrussell

CHawes

SStuchell

MMurphy

TMcGinty TRQ

for

DATE

01/05/2009

01/07/2009

1/28/2009

1/28/2009

1/29/2009

1/29/2009

Retrieved from "https://kanterella.com/w/index.php?title=ML090120669&oldid=5321502"