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{{#Wiki_filter:UNITED STATES
{{#Wiki_filter:UNITED STATES  
                            NUCLEAR REGULATORY COMMISSION
                        OFFICE OF NUCLEAR REACTOR REGULATION
NUCLEAR REGULATORY COMMISSION  
                                  WASHINGTON, DC 20555-0001
                                          January 29, 2009
OFFICE OF NUCLEAR REACTOR REGULATION  
                  NRC REGULATORY ISSUE SUMMARY 2009-02
  USE OF CONTAINMENT ATMOSPHERE GASEOUS RADIOACTIVITY
WASHINGTON, DC 20555-0001  
MONITORS AS REACTOR COOLANT SYSTEM LEAKAGE DETECTION
                EQUIPMENT AT NUCLEAR POWER REACTORS
ADDRESSEES
January 29, 2009  
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.
NRC REGULATORY ISSUE SUMMARY 2009-02  
All current and potential applicants for a combined license, manufacturing license, standard
USE OF CONTAINMENT ATMOSPHERE GASEOUS RADIOACTIVITY  
design certification, or standard design approval for a nuclear power plant under the provisions
MONITORS AS REACTOR COOLANT SYSTEM LEAKAGE DETECTION  
of Title 10 of the Code of Federal Regulations, Part 52 (10 CFR), Licenses, Certifications, and
EQUIPMENT AT NUCLEAR POWER REACTORS  
Approvals for Nuclear Power Plants.
All applicants for nuclear power plant construction permits and operating licenses under the
ADDRESSEES  
provisions of 10 CFR Part 50, Domestic Licensing of Production and Utilization Facilities.
       
INTENT
All holders of operating licenses for nuclear power reactors except those who have permanently  
The U.S. Nuclear Regulatory Commission (NRC) is issuing this regulatory issue summary (RIS)
ceased operations and have certified that fuel has been permanently removed from the reactor  
to communicate the NRC plan to address the situation created when some containment
vessel.  
atmosphere gaseous radioactivity monitors are unable to meet technical specification (TS)
requirements. The plan consists of integrating a streamlined license amendment process with
All current and potential applicants for a combined license, manufacturing license, standard  
the use of enforcement discretion, where appropriate. This RIS requires no action or written
design certification, or standard design approval for a nuclear power plant under the provisions  
response on the part of an addressee.
of Title 10 of the Code of Federal Regulations, Part 52 (10 CFR), Licenses, Certifications, and  
BACKGROUND INFORMATION
Approvals for Nuclear Power Plants.  
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
All applicants for nuclear power plant construction permits and operating licenses under the  
their plant designs because the equipment can be used to detect reactor coolant pressure
provisions of 10 CFR Part 50, Domestic Licensing of Production and Utilization Facilities.  
boundary (RCPB) leakage. A typical RCS leakage detection system consists of a combination
of the following:
INTENT  
*       a containment atmosphere particulate radioactivity monitoring system
*       a containment atmosphere gaseous radioactivity monitoring system
The U.S. Nuclear Regulatory Commission (NRC) is issuing this regulatory issue summary (RIS)  
*       containment sump-level and sump-pump instrumentation
to communicate the NRC plan to address the situation created when some containment  
*       containment cooler condensate monitoring instrumentation
atmosphere gaseous radioactivity monitors are unable to meet technical specification (TS)  
ML090120669
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
RIS 2009-02  
                                                                                          Page 2 of 5
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
Containment atmosphere gaseous radioactivity monitoring systems measure RCS leakage  
length of time required for these monitoring systems to detect a given volume of RCS leakage.
indirectly by detecting airborne radioactivity released from RCS leakage. Response time is the  
Response time is dependant on RCS radioactivity concentration, as well as other variables. For
length of time required for these monitoring systems to detect a given volume of RCS leakage.
a given volume of leakage, with all other variables held constant, a higher RCS radioactivity
Response time is dependant on RCS radioactivity concentration, as well as other variables. For  
concentration will yield a shorter response time for these monitoring systems. The design
a given volume of leakage, with all other variables held constant, a higher RCS radioactivity  
analyses for the containment atmosphere gaseous radioactivity monitoring systems used in the
concentration will yield a shorter response time for these monitoring systems. The design  
licensing bases for most plants typically assume a RCS radioactivity concentration
analyses for the containment atmosphere gaseous radioactivity monitoring systems used in the  
approximately equivalent to 0.1 percent failed fuel in the core. Improvements in fuel cladding
licensing bases for most plants typically assume a RCS radioactivity concentration  
integrity and RCS chemistry controls have significantly reduced RCS radioactivity concentration
approximately equivalent to 0.1 percent failed fuel in the core.   Improvements in fuel cladding  
at most plants. As a result, the monitors for operating units may have longer response times
integrity and RCS chemistry controls have significantly reduced RCS radioactivity concentration  
than they would with 0.1 percent failed fuel in the core because the actual RCS radioactivity
at most plants. As a result, the monitors for operating units may have longer response times  
concentration is less than it would be with 0.1 percent failed fuel in the core.
than they would with 0.1 percent failed fuel in the core because the actual RCS radioactivity  
Most plants have TS Limiting Conditions for Operation requirements for containment
concentration is less than it would be with 0.1 percent failed fuel in the core.  
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
Most plants have TS Limiting Conditions for Operation requirements for containment  
design analysis that is part of a plants licensing basis. If the monitors fail to meet these
atmosphere gaseous radioactivity monitoring systems used as part of RCS leakage detection  
requirements, the monitors are inoperable. When the monitors are inoperable the licensee is
equipment. The TS requirements for the monitoring systems response times are based on the  
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  
Information Notice (IN) 2005-24, Nonconservatism in Leakage Detection Sensitivity
requirements, the monitors are inoperable. When the monitors are inoperable the licensee is  
(ADAMS Accession No. ML051780073), communicated the issue created by differences
required to take remedial actions as permitted by their TS or to shut down the reactor.  
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
Information Notice (IN) 2005-24, Nonconservatism in Leakage Detection Sensitivity  
atmosphere gaseous radioactivity monitors used as part of RCS leakage detection equipment
(ADAMS Accession No. ML051780073), communicated the issue created by differences  
and consider appropriate actions as applicable to their plants. Information Notices do not
between actual and assumed RCS radioactivity concentrations to all licensees. The purpose of  
require any action by licensees.
IN 2005-24 was to have licensees review information related to problems with containment  
In September 2008, NRC inspectors at the Diablo Canyon Power Plant identified a non-cited
atmosphere gaseous radioactivity monitors used as part of RCS leakage detection equipment  
violation for not complying with TS requirements for RCS leakage detection equipment. In
and consider appropriate actions as applicable to their plants. Information Notices do not  
November 2008, the licensee for the Watts Bar Nuclear Plant and the Sequoyah Nuclear Plant
require any action by licensees.  
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
In September 2008, NRC inspectors at the Diablo Canyon Power Plant identified a non-cited  
monitor channels of the RCS leakage detection system were inoperable.
violation for not complying with TS requirements for RCS leakage detection equipment. In  
To address the issue, licensees working through the industry-sponsored Technical
November 2008, the licensee for the Watts Bar Nuclear Plant and the Sequoyah Nuclear Plant  
Specifications Task Force (TSTF) have attempted to create generic TS changes, model License
requested exigent license amendments from the NRC after taking remedial actions as permitted  
Amendment Requests (LARs), model safety evaluations, and model proposed
by their TS because of a concern that the containment atmosphere gaseous radioactivity  
no-significant-hazards consideration determinations using the NRC TS Consolidated Line Item
monitor channels of the RCS leakage detection system were inoperable.  
Improvement Process (CLIIP). See RIS 2000-10, Consolidated Line Item Improvement
Process For Adopting Standard Technical Specifications Changes for Power Reactors
To address the issue, licensees working through the industry-sponsored Technical  
(ADAMS Accession No. ML003693442) for more information on the NRC CLIIP.
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
RIS 2009-02  
                                                                                        Page 3 of 5
Page 3 of 5  
SUMMARY OF ISSUE
Improvements in fuel cladding integrity and RCS chemistry controls result in lower RCS
SUMMARY OF ISSUE  
radioactivity concentrations during operational activities, including situations where there is RCS
leakage. Thus, containment atmosphere gaseous radioactivity monitoring systems which are
Improvements in fuel cladding integrity and RCS chemistry controls result in lower RCS  
designed on the basis of higher assumed RCS radioactivity concentrations will not provide
radioactivity concentrations during operational activities, including situations where there is RCS  
accurate indication of RCS leakage in the required length of time due to the longer response
leakage. Thus, containment atmosphere gaseous radioactivity monitoring systems which are  
time of the monitoring system, and must be considered inoperable.
designed on the basis of higher assumed RCS radioactivity concentrations will not provide  
The NRC considers the longer response times of the containment atmosphere gaseous
accurate indication of RCS leakage in the required length of time due to the longer response  
radioactivity monitors to be of very low safety significance. The monitors would still be able to
time of the monitoring system, and must be considered inoperable.  
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
The NRC considers the longer response times of the containment atmosphere gaseous  
detect RCS leakage and to provide licensees with a means to detect significant RCPB
radioactivity monitors to be of very low safety significance. The monitors would still be able to  
degradation and to take appropriate action to ensure the continued protection of public health
detect degradation in the RCPB long before components fail in a manner that would affect plant  
and safety. Finally, nuclear power plants are designed to provide adequate core cooling
safety. Additionally, plants also have multiple diverse and redundant methods available to  
following postulated loss-of-coolant accidents up to and including a break equivalent in size to
detect RCS leakage and to provide licensees with a means to detect significant RCPB  
the double-ended rupture of the largest pipe in the RCS. This design feature, coupled with the
degradation and to take appropriate action to ensure the continued protection of public health  
extremely low likelihood of unstable crack growth resulting in a loss-of-coolant accident, leads
and safety. Finally, nuclear power plants are designed to provide adequate core cooling  
the NRC to conclude that the risk significance of this issue is very low.
following postulated loss-of-coolant accidents up to and including a break equivalent in size to  
The NRC plans to address the issue of inoperable containment atmosphere gaseous
the double-ended rupture of the largest pipe in the RCS. This design feature, coupled with the  
radioactivity monitoring systems in an integrated fashion by: (i) working with the TSTF to
extremely low likelihood of unstable crack growth resulting in a loss-of-coolant accident, leads  
develop revised generic TS for the monitoring system, and facilitating licensee implementation
the NRC to conclude that the risk significance of this issue is very low.  
of the revised generic TS through a streamlined license amendment process; and (ii) issuing
guidance on NRCs exercise of enforcement discretion involving inoperable containment
The NRC plans to address the issue of inoperable containment atmosphere gaseous  
atmosphere gaseous radioactivity monitoring systems.
radioactivity monitoring systems in an integrated fashion by: (i) working with the TSTF to  
The NRC will review the generic TS changes that the TSTF proposes for pressurized-water
develop revised generic TS for the monitoring system, and facilitating licensee implementation  
reactors (PWRs) and boiling-water reactors (BWRs). If the generic TS changes are found to be
of the revised generic TS through a streamlined license amendment process; and (ii) issuing  
acceptable, the NRC will make the generic model LARs, model safety evaluations, and model
guidance on NRCs exercise of enforcement discretion involving inoperable containment  
no-significant-hazards consideration determinations available to licensees using the NRC CLIIP.
atmosphere gaseous radioactivity monitoring systems.
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.
The NRC will review the generic TS changes that the TSTF proposes for pressurized-water  
On November 14, 2008, the TSTF submitted TSTF-513, Revise Operability Requirements and
reactors (PWRs) and boiling-water reactors (BWRs). If the generic TS changes are found to be  
Actions for RCS Leakage Instrumentation, to the NRC for review. TSTF-513 proposes generic
acceptable, the NRC will make the generic model LARs, model safety evaluations, and model  
TS changes for PWRs. The TSTF plans to submit TSTF-514 to the NRC in January 2009.
no-significant-hazards consideration determinations available to licensees using the NRC CLIIP.  
TSTF-514 will propose generic TS changes for BWRs. Licensees are free to submit LARs to
Licensees are free to submit LARs for TS changes to address the issue. If licensees deem  
address the issue using TSTF-513 or TSTF-514; or they can propose alternative solutions.
further action regarding the issue is unwarranted, they can choose to take no action.  
In certain circumstances involving inoperable containment atmosphere gaseous radioactivity
monitoring systems, enforcement discretion is available. Specific guidance for this enforcement
On November 14, 2008, the TSTF submitted TSTF-513, Revise Operability Requirements and  
discretion is described in EGM-09-001 (ADAMS Accession No. ML090300467) and is available
Actions for RCS Leakage Instrumentation, to the NRC for review. TSTF-513 proposes generic  
on the NRCs web site at www.nrc.gov.
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
RIS 2009-02  
                                                                                        Page 4 of 5
Page 4 of 5  
BACKFIT DISCUSSION
The intent of this RIS is to inform addressees of the NRCs plan to address the failure of
BACKFIT DISCUSSION  
containment atmosphere gaseous radioactivity monitors used as RCS leakage detection
equipment to meet TS requirements.
The intent of this RIS is to inform addressees of the NRCs plan to address the failure of  
The staff is not imposing any new positions on licensees. This RIS is not providing any new
containment atmosphere gaseous radioactivity monitors used as RCS leakage detection  
regulatory positions. This RIS only conveys the NRCs plan to address the issue of RCS
equipment to meet TS requirements.  
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
The staff is not imposing any new positions on licensees. This RIS is not providing any new  
staff did not perform a backfit analysis.
regulatory positions. This RIS only conveys the NRCs plan to address the issue of RCS  
FEDERAL REGISTER NOTIFICATION
leakage detection equipment failing to meet TS requirements because of the difference between  
A notice of opportunity for public comment on this RIS was not published in the Federal Register
actual and assumed RCS radioactivity concentrations. This RIS requires no action or written  
because it is informational and pertains to a staff position that does not represent a departure
response and, therefore, is not a backfit under 10 CFR 50.109, Backfitting. Consequently, the  
from current regulatory requirements and practice. However, a public meeting to discuss this
staff did not perform a backfit analysis.  
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
FEDERAL REGISTER NOTIFICATION  
documents.
CONGRESSIONAL REVIEW ACT
A notice of opportunity for public comment on this RIS was not published in the Federal Register  
This RIS is not a rule as designated by the Congressional Review Act (5 U.S.C. §§ 801-808)
because it is informational and pertains to a staff position that does not represent a departure  
and, therefore, is not subject to the Act.
from current regulatory requirements and practice. However, a public meeting to discuss this  
PAPERWORK REDUCTION ACT STATEMENT
RIS was held on January 8, 2009. The meeting summary is available under ADAMS Accession  
This RIS does not contain any information collections and, therefore, is not subject to the
No. ML090130583. The NRC intends to work with industry representatives, members of the  
requirements of the Paperwork Reduction Act of 1995 (44 U.S.C. 3501, et seq.).
public, and other stakeholders in developing final guidance and in modifying related guidance  
                              PUBLIC PROTECTION NOTIFICATION
documents.  
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
CONGRESSIONAL REVIEW ACT  
currently valid OMB control number.
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
RIS 2009-02  
                                                                                      Page 5 of 5
Page 5 of 5  
CONTACT
Please direct any questions about this matter to the technical contact listed below or to the
CONTACT  
appropriate Office of Nuclear Reactor Regulation (NRR) project manager.
                                    /RA by Theodore R. Quay For/
Please direct any questions about this matter to the technical contact listed below or to the  
                                    Timothy J. McGinty, Director
appropriate Office of Nuclear Reactor Regulation (NRR) project manager.  
                                    Division of Policy and Rulemaking
                                    Office of Nuclear Reactor Regulation
Technical Contact: Matthew Hamm, NRR
/RA by Theodore R. Quay For/  
                    301-415-1472
                    e-mail: matthew.hamm@nrc.gov
Timothy J. McGinty, Director  
Note: NRC generic communications may be found on the NRC public Web site,
Division of Policy and Rulemaking  
http://www.nrc.gov, under Electronic Reading Room/Document Collections.
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
RIS 2009-02  
                                                                                          Page 5 of 5
Page 5 of 5  
    CONTACT
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.
Please direct any questions about this matter to the technical contact listed below or to the  
                                        /RA by Theodore R. Quay For/
appropriate Office of Nuclear Reactor Regulation (NRR) project manager.  
                                        Timothy J. McGinty, Director
                                        Division of Policy and Rulemaking
                                        Office of Nuclear Reactor Regulation
/RA by Theodore R. Quay For/  
    Technical Contact: Matthew Hamm, NRR
                        301-415-1472
Timothy J. McGinty, Director  
                        e-mail: matthew.hamm@nrc.gov
Division of Policy and Rulemaking  
    Note: NRC generic communications may be found on the NRC public Web site,
Office of Nuclear Reactor Regulation  
    http://www.nrc.gov, under Electronic Reading Room/Document Collections.
    ADAMS ACCESSION No. ML090120669
OFFICE     ITSB:DIRS     Tech Editor     BC:ITSBDIRS D:DIRS               PSPB DPR       BC:PSPB DPR
Technical Contact: Matthew Hamm, NRR  
NAME       MHamm         via email       RElliott         FBrown         JWilliams       SRosenberg
        301-415-1472  
                                                            MCheok for                      DNelson for
e-mail: matthew.hamm@nrc.gov  
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
Note: NRC generic communications may be found on the NRC public Web site,  
NAME       WRuland       for JGiitter     DLew via         LWert via       CPederson       DChamberlain
http://www.nrc.gov, under Electronic Reading Room/Document Collections.  
                                          email            email          via email       via email
DATE       1/12/2009     12/30/2008       1/15/2009       1/14/2009       1/13/2009       1/15/2009
ADAMS ACCESSION No. ML090120669  
OFFICE     D:DCI         BC:CHPB                           OE             OGC (NLO)       OGC (CRA)
OFFICIAL RECORD COPY
                                          D: DCIP/NRO
                          DCIP
OFFICE  
NAME      MEvans         TFrye           GTracy           DStarkey       BJones         NSanchez
                          CHinson for                      via email                      via email
ITSB:DIRS  
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
Tech Editor  
NAME       LHill         GTrussell       CHawes           SStuchell       MMurphy         TMcGinty TRQ
BC:ITSBDIRS
                                                                                            for
D:DIRS  
DATE       01/05/2009     01/07/2009       1/28/2009       1/28/2009       1/29/2009     1/29/2009
PSPB DPR  
    OFFICIAL RECORD COPY
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  
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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

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