ML17158B715
| ML17158B715 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 07/03/1996 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML17158B714 | List: |
| References | |
| NUDOCS 9607100218 | |
| Download: ML17158B715 (6) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 2055&0001 SAF TY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION PENNSYLVANIA POWER
& LIGHT COMPANY ALLEGHENY ELECTRIC COOPERATIVE INC.
SUS UEHANNA STEAM ELECTRIC STATION UNITS 1
AND 2 DOCKET NOS.
50-387 AND 388
- 1. 0 INTRODUCTION By letter dated April 17,
- 1995, as supplemented March 12,
- 1996, the Pennsylvania Power and Light Company (the licensee) submitted a request for changes to the Bases of the plant Technical Specifications (TSs) for Susquehanna Steam Electric Station, Units 1 and 2.
The requested changes would add the following paragraph to the Bases for TS 3/4.3.7.5, "Accident Monitoring Instrumentation," for both units:
The Neutron Monitoring Systems (NHS) was evaluated against the criteria established in General Electric NEDO-31558A to ensure its acceptability for post-accident monitoring.
NEDO-31558A provides alternative criteria for the NHS to meet the post-accident monitoring guidance of Regulatory Guide 1.97.
Based on the evaluation, the NMS was found to meet the criteria established in NEDO-31558A.
The APRM subfunction of the NHS is used to provide the Neutron Flux monitoring identified in TS 3.3.7.5.
The proposed paragraph would explain that the NHS would be used at both units to provide neutron flux monitoring in post-accident conditions.
- 2. 0 EVALUATION The Boiling Water Reactor (BWR) Owner's Group submitted General Electric Report NED0-31558, "BWR Owner's Group Licensing Topical Report, Position on NRC Regulatory Guide 1.97, Revision 3 Requirements for Post-Accident Neutron Monitoring System," in a letter dated April 1, 1988.
This report was submitted to support deviations from the regulatory guide position for neutron flux monitoring instrumentation in Regulatory Guide (RG) 1.97,
" Instrumentation for Light-Water-Cooled Nuclear Power Plants to Assess Plant and Environs Conditions During and Following an Accident," Revision 3, dated May 1983.
The staff approved, for existing BWRs, including Susquehanna, the alternative criteria in NEDO-31558 for neutron flux monitoring instrumentation during and following an accident in its letter dated January 13, 1993, to the BWR Owner's Group.
The staff's safety evaluation was sent to the licensee for Susquehanna Steam Electric Station as an attachment to a letter dated November 28, 1994.
96071002i8 960703 l
PDR ADOCK 05000387 P
The staff stated in the evaluation that licensees should review the instrumentation in their neutron flux monitoring systems against the criteria in NEDO-31558 and confirm that the instrumentation meets this criteria.
The staff did not approve any specific system in a BWR.
In its letter dated April 17, 1995, the licensee for Susquehanna Steam Electric Station stated that NEDO-31558 applied to the two units and that the NMS-meets the NEDO-31558 criteria.
The licensee, therefore, has adopted the alternate criteria established in NEDO-31558 for neutr on flux monitoring instrumentation instead of the criteria stated in RG 1.97, Revision 3.
The NHS is replacing the ex-core neutron flux monitor as the instrument for the. instrument for post-accident neutron flux monitoring at the two units.
The NMS is described in Section 7.6. la.5 of the Final Safety Analysis Report (FSAR) for Susquehanna Steam Electric Station, Units 1 and 2.
Its purpose is to monitor power (i.e., neutron flux) in the core and provide signals to the reactor protection system (RPS) and the rod block portion of the reactor manual control system.
It also provides information for the operation and control of the reactor.
The average power range monitor (ARPH) subsystem of the NMS has channels associated with each trip system of the RPS.
The NHS is an appropriate system to monitor the neutron flux and the licensee has stated that it meets the criteria in NED0-31558.
The proposed paragraph would be added to the Bases for TS 3/4.3.7.5.
This TS provides the requirements on the accident monitoring instrumentation for the two units and is the appropriate TS for the proposed paragraph.
The licensee has also stated that actions have been taken to update the Final Safety Analysis Report for Units 1 and 2, and the plant procedures and programs.
The licensee stated that current requirement in TS 3/4.3.7.5 for post-accident neutron flux instrument will be kept in the TSs.
Therefore, the requirements for this instrument in the TSs (i.e., required number of
- channels, minimum channels
- operable, applicable operational conditions, channel
- check, and channel calibration) will not be changed by designating the NMS for this monitoring function.
For the Unit 2 TS 3/4.3.7.5, the required number of channels and minimum number of channels for the neutron flux instrument was reduced to 1 and 0, respectively, in Amendment 115 on March 1, 1995.
The licensee stated that, with the designation of the NMS as the instrument for monitoring the neutron flux in post-accident conditions, an amendment request will be submitted to return these values back to 2 and 1,
as they are in the Unit 1 TSs.
Until this amendment request is acted on, the licensee stated that administrative controls will be placed on the Unit TS 3/4.3.7.5 to ensure the required number of channels and minimum number of channels for the NMS will be 2 and 1,
respectively.
0
- 3. 0 CONCLUSION The license proposed to add a paragraph to the Bases for TS 3/4 ' '
about the NHS being the instrument used. to monitor the neutron flux in post-accident conditions.
The paragraph is being added to the appropriate TS on post accident monitoring instrument.
The NHS is an appropriate system in the units to monitor the neutron 'flux and the li'censee has stated that the NHS meets the criteria in NEDO-31558 for post-accident neutron flux monitoring.
This is criteria that the staff has accepted for this post-accident functions Therefore, the proposed paragraph and its addition to the Bases for TS 3/4.3.7 '
are acceptable to explain that the NHS is the instrument to monitor the neutron flux in post-accident conditions at Units 1 and 2
The actions to update the FSAR and plant procedures, and the administrative controls on the Unit 2 TS 3/4
~ 3 ~ 7 ~ 5 discussed
- above, are correct actions in implementing the decision to have the NHS be the instrument for post-accident neutron flux monitoring Principal Contributor:
J.
Donohew Date:
Pu]y 3
]996
BASES The OPERABILITY of the meteorological monitoring instrumentation ensures that sufficient meteorological data is available for estimating potential radiation doses to the public as a result of routine or accidental release of radioactive materials to the atmosphere.
This capability is required to evaluate the need for initiating protective measures to protect the health and safety of the public.
This instrumentation is consistent with the recommendations of Regulatory Guide 1.23 "Onsite Meteorological Programs," February, 1972.
The OPERABILITY of the remote shutdown monitoring instrumentation ensures that sufficient capability is available to permit shutdown and maintenance of HOT SHUTDOWN of the unit from locations outside of the control room.
This capability is required in the event control room habitability is lost and is consistent with General Design Criteria 19 of 10 CFR 50.
The OPERABILITY of the accident monitoring instrumentation ensures that sufficient information is available on selected plant parameters to monitor and assess important variables following an accident.
This capability is consistent with the recommendations of Regulatory Guide 1.97, "Instrumentation for Light Water Cooled Nuclear Power Plants to Assess Plant Conditions During and Following an Accident," December 1975 and NUREG-0578, "TMI-2 Lessons Learned Task Force Status Report and Short-Term Recommendations".
The Neutron Monitoring System (NMS) was evaluated against the criteria established in General Electric NEDO-31558A to ensure its acceptability for post-accident monitoring.
NEDO-31558A provides alternative criteria for the NMS to meet the post-accident monitoring guidance of Regulatory Guide 1.97.
Based on the evaluation, the NMS was found to meet the criteria established in NEDO-31558A.
The APRM sub-function of the NMS is used to provide the Neutron Flux monitoring identified in TS 3.3.7.5.
The source range monitors provide the operator with information of the status of the neutron level in the core at very low power levels during startup and shutdown. At these power levels, reactivity additions should not be made without this flux level information available to the operator.
When the intermediate range monitors are on scale adequate information is available without the SRMs and they can be retracted.
The OPERABILITYof the traversing in-core probe system with the specified minimum complement of equipment ensures that the measurements obtained from use of this equipment accurately represent the spatial neutron flux distribution of the reactor core.
SUSQUEHANNA - UNIT 1 B 3/4 3-5 Corrected by Letter dated ~uly 3, 1996
BASES The OPERABILITY of the meteorological, monitoring instrumentation ensures that sufficient meteorological data is available for estimating potential radiation doses to the public as a result of routine or accidental release of radioactive materials to the atmosphere.
This capability is required to evaluate the need for initiating protective measures to protect the health and safety of the public.
This instrumentation is consistent with the recommendations of Regulatory Guide 1.23 "Onsite Meteorological Programs," February, 1972.
The OPERABILITY of the remote shutdown monitoring instrumentation ensures that sufficient capability is available to permit shutdown and maintenance of HOT SHUTDOWN of the unit from locations outside of the control room.
This capability is required in the event control room habitability
" is lost and is consistent with General Design Criteria 19 of 10 CFR 50.
The OPERABILITY of the accident monitoring instrumentation ensures that sufficient information is available on selected plant parameters to monitor and assess important variables following an accident.
This capability is consistent with the recommendations of Regulatory Guide 1.97, "Instrumentation for Light Water Cooled Nuclear Power Plants to Assess Plant Conditions During and Following an Accident," December 1975 and NUREG-0578, "TMI-2 Lessons Learned Task Force Status Report and Short-Term Recommendations".
The Neutron Monitoring System (NMS) was evaluated against the criteria established in General Electric NEDO-31558A to ensure its acceptability for post-accident monitoring.
NEDO-31558A provides alternative criteria for the NMS to meet the post-accident monitoring guidance of Regulatory Guide 1.97.
Based on the evaluation, the NMS was found to meet the criteria established in NEDO-31558A.
The APRM sub-function of the NMS is used to provide the Neutron Flux monitoring identified in TS 3.3.7.5.
The source range monitors provide the operator with information of the status of the neutron level in the core at very low power levels during startup and shutdown. At these power levels, reactivity additions should not be made without this flux level information available to the operator.
When the intermediate range monitors are on scale adequate information is available without the SRMs and they can be retracted.
The OPERABILITYof the traversing in-core probe system with the specified minimum complement of equipment ensures that the measurements obtained from use of this equipment accurately represent the spatial neutron flux distribution of the reactor core.
SUSQUEHANNA - UNIT 2 B 3/4 3-5 Corrected by Letter dated Jul y 3, 1 996