ML20236R387
| ML20236R387 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 07/13/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20236R386 | List: |
| References | |
| GL-95-10, NUDOCS 9807210423 | |
| Download: ML20236R387 (6) | |
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g UNITED STATES j
j NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 30086 0001 4
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGUI.ATION RELATED TO AMENDMENT NOS.192 AND 191 TO FACILITY OPERATING LICENSE NOS. DPR-51 AND NPF-6 ENTERGY OPERATIONS.E ARKANSAS NUCLEAR ONE. UNIT ICMAJQ.2 DOCKET NOS. 50-313 AND 50Jff
1.0 INTRODUCTION
By letter dated October 2,1996, Entergy Operations, Inc. (the licensce) submitted a request for changes to the Arkansas Nuclear One, Units 1 and 2 (ANO-1&2), Technical Specifications (TSs).
The requested changes would revise the ANO-1&2 TSs by relocating selected TS requirements related to instrumentation from the TS to the Updated Final Safety Analysis Report (UFSAR).
The Nuclear Regulatory Commission (NRC) provided guidance to all holders of operating licenses or construction permits for nuclear power reactors on the proposed TS changes in l
Generic Letter 95-10, " Relocation of Selected Technical Specifications Requirements Related to Instrumentation," dated December 15,1995.
2.0 BACKGROUND
Section 182a of the Atomic Energy Act (the "Act") requires applicants for nuclear power plant operating licenses to include TS as part of the license. The Commission's regulatory requirements related to the content of TS are set forth in 10 CFR 50.36. That regulation requires that the TS include items in five specific categories, including (1) safety limits, limiting safety system settings and limiting control settings; (2) limiting conditions for operation; (3) surveillance requirements; (4) design features; and (5) administrative controls.
Section 50.36 requires limiting conditions for operation which meet any of the following criteria to be in the TS:
(1) installed instrumentation that is used to detect, and indicate in the control room, a significant abnormal degradation of the reactor coolant pressure boundary; (2)
A process variable, design feature, or operating restriction that is an initial condition of a Design Basis Accident or Transient analysis that either assumes the failure of or presents a challenge to the integrity of a fission product barrier; (3)
A structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a Design Basis Accident orTransient that either assumes the failure of or presents a challenge to the integrity of a fission
. product barrier, and
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A structure, system, or component which operating experience or probabilistic safety assessment has shown to be significant to public health and safety.
As a result., existing TS requirements which fall within or satisfy any of the criteria must be retained in the TS, while those TS requirements which do not fall within or satisfy these critaria may be relocated to other, licensee-controlled documents.
3.0 EVALUATION The requested amendments would relocate selected TS requirements related to instrumentation from the TS to the Technical Requirements Manual (TRM). The TRM is a part of the UFSAR.
The relocated requirements for ANO-1 include the limiting conditions for operation and related surveillance requirements for:
TS 3.5.1.10 Control Room Ventilation Chlorins Detection System TS 3.5.1.13 Seismic Monitoring Instrumentation Table 3.5.1-1 Instrumentation Limiting Conditions for Operation item 9 - Chlorine Detection System item 14 - Seismic Monitoring Instrumentation Note 27 - Seismic Monitoring instrumentation Action Statement Table 4.1-1 Instrumentation Surveillance Requirements item 31 - Turbine Overspeed Trip Mechanism item 42 - Seismic Monitoring Instruments item 52 - Control Room Chlorine Detector The relocated requirements for ANO-2 include the following limiting conditions for operaCon and related surveillance requirements:
TS 3/4.3 3.3 Seismic Instrumentation (including Tables 3.3.7 and 4.3.4)
TS 3/4.3.3.4 Meteorological Instrumentation (including Tables 3.3.8 and 4.3.5)
TS 3/4.3.3.7 Chlorine Detection Systems TS 3/4. 3.4 Turbine Overspeed Protection TS 3/4.7.6(d)
Delete Surveillance for Controi Room isolation on High Chlorine Test Olgnal The staff's evaluation of the various proposed relocations are provided below:
SEISMIC INSTRUMENTATION (ANO 1 TS 3.5.1.13. Table 3.5.1-1. and Table 4.1-1: ANO-2 TS 3/4.3.3.3)
Section Vl(s)(3) of Appendix A to 10 CFR Part 100, requires that seismic monitoring instrumentation be provided to promptly determine the response of those nuclear power plant
3 features important to safety in the event of an earthquake. This capability is required to allow for a comparison of the measured response to that used in the design basis for the unit.
Comparison of such data is needed to (1) determine whether the plant can continue to be operated safely, and (2) permit such timely action as may be appropriate. The requirements do not address the,need for seismic monitoring instrumentation that would automatically shut down the plant when an earthquake occurs which exceeds a predetermined intensity. The licensee has proposed to relocate these provisions to the UFSAR such that future changes to the operation and surveillance of the seismic monitoring instrumentation could be changed under 10 CFR 50.59.
The capability of the plant to withstand a seismic event or other design-basis accident is detemined by the initial design and construction of systems, structures, and components. The instrumentation is used to alert operators to the seismic event and evaluate the plant response.
The Final Policy Statement explained that instrumentation to detect precursors to reactor coolant pressure boundary leakage, such as seismic instrumentation, is not included in the first criterion.
As discussed above, the seismic instrumentation does not serve as a protective design feature or part of a primary success path for events which challenge fission product barriers.
Accordingly, the staff has concluded that the requirements for seismic monitoring instrumentation do not meet the criteria in 10 CFR 50.36. The limiting conditions for operation and surveillance requirements for s6mic monitoring instrumentation were removed from the latest versions of the standard tachnical specifications for all reactor types (including Standard Technical Specifications Babcock and Wilcox Plants, NUREG-1430, and Standard Technical Specifications for Combustion Engine Mg Plants, NUREG-1432).
CHLORINE DETECTION SYSTEM (ANO-1 TS 3.5.1.10. Table 3.5.1-1. and Table 4.1-1: ANO-2 TS 3/4.3.3.7)
Chlorine detection systems ensure that sufficient capability is available to promptly detect and initiate protective action to isolate the control room in the event of an accidental chlorine release.
Normal plant operation could be hampered in the event of the accidental release of chlorine from onsite or offsite sources. Staff positions regarding the relationship of the chlorine detection systems to the general design criteria (GDC) appear in NUREG-0800, " Standard Review Plan" (SRP); Regulatory Guida (RG) 1.78, " Assumptions for Evaluating the Habitability of a Nuclear Power Plant Control Room During a Postulated Hazardous Chemical Release"; and RG 1.95,
" Protection of Nuclear Power Plant Control Room Operators Against an Accidental Chlorine Releasa." The licensee has proposed to relocate these provisions to the UFSAR such that future changes to the operation and surveillance of the chlorine detection system could be made under 10 CFR 50.59.
As discussed above, chlorine detection systems may serve an irnportant role in the protection of control room personnel from intemal or extemal hazards related to toxic gases. However, the release of chlorine or other hazardous chemicals is not part of an initial condition of a design basis accident or transient analysis that assumes a failure of or presents a challenge to the integrity of a fission product barrier. Since the release of toxic gases is not assumed to initiate or occur simultaneously with design basis accidents or transients involving challenges to fission product barriers, the chlorine detection system is not part of a success path for the mitigation of
~ those accidents or transients.
4 Accordingly, the staff has concluded that the requirements for chlorine [ toxic gas) detection systems do not meet the criteria in 10 CFR 50.36. The limiting conditions for operation and surveillance requirements for chlorine detection systems were removed from the latest versions of the standard technical specifications for all reactor types (including Standard Technical Specifications Babcock and Wilcox Plants, NUREG-1430, and Standard Technical Specifications for Combustion Engineering Plants, NUREG-1432).
TURBINE OVERSPtiED PROTECTION (ANO-1 TS Table 4.1-1. ANO-2 TS 3/4.3.4)
General Design Criterion 4 of Appendix A to 10 CFR Part 50 requires that structures, systems, and components important to safety be appropriately protected from the effects of missiles that may result from equipment failures. The turbine is equipped with control valves and stop valves which control turbine speed during normal plant operation and protect it from overspeed during abnormal conditions. The turbine overspeed protection system consists of separate mechanical and electrical sensing mechanisms'which are capable of initiating fast closure of the steam valves. Currently, ANO-1 TS require a test of the turbine overspeed trip mechanism on a refueling outage frequency and ANO-2 TS 3/4.3.4 requires particular operability and surveillance requirements for these steam control and stop valves to minimize the potential for fragment missiles that might be generated as the result of a turbine overspeed event. The licensee has proposed to relocate these provisions to the TRM such that future changes to the operation and surveillance of the turbine overspeed features could be changed under 10 CFR 50.59.
Although the design basis accidents and transients include a variety of system failures and conditions which might result from turbine overspeed events and potential missiles striking various plant systems and equipment, the system failures and plant conditions are much more I;kely to be caused by events other than turbine fai;ures. In view of the low likelihood of turbine missiles, assumptions related to the turbine overspeed protection system are not part of an initial condition of a design basis accident or transient thet either assumes the failure of or presents a challenge h the integrity of a fission product barrier. The turbine overspeed protection system is not relied upon in the design basis accident or transient analyses as a primary success path which functions or actuates to mitigate such events. Probabilistic safety assessments and operating experience have demonstrated that proper maintenance of the turbine overspeed control valves is important to minimize the potential for overspeed events and turbine damage; however that experience has also demenC1.;ilms inere is,v.. Miiood of significant risk to public health and safety because of turbine overspeed events. Further, the potential for and consequences of turbine overspeed events are diminished by the favorable orientation of the turbine, relative to the likely path of any turbine missiles, and the licensee's inservice inspection program, which must comply with 10 CFR 50.55(a), and a surveillance program for the turbine control and stop valves derived from the manufacturer's recommendations.
Accordingly, the staff has concluded that the requirernents for turbine overspeed protection do not meet the 10 CFR 50.36 criteria for inclusion in the TS and may be relocated to the UFSAR, 1
where future changes to the reqdrements may be made under 10 CFR 50.59. The limiting l
conditions for operation and surveillance requirements for turbine overspeed protection were not i
included in the latest versions of the standard technical specifications for all reactor types j
(including Standard Technical Specifications Babcock and Wilcox Plants, NUREG-1430, and Standard Technical Specifications for Combustion Engineering Plants, NUREG-1432).
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5 METEOROLOGICAL MONit _ WG INSTRUMENTATION (ANO-2 TS 3/4.3.3.4)
The meteorological monitoring instrumentation is used to measure environmental parameters (wind direction, speed, and air temperature differences) which may affect the distribution of radioactive effluents following a release of radioactive material. In 10 CFR 50.47," Emergency Plans," and 10 CFR Part 50, Appendix E, " Emergency Planning and Preparedness for Production and Utilization Facilities," the Commission requires power plant licensees to provide reasonable assurance that adequate protective measures can and will be taken in the event of a radiological emergency. Timely access to accurate local meteorological data is important for estimating potential mdiation doses to the public and for determining appropriate protective measures. In 10 CFR 50.36a(a)(2), the Commission requires nuclear power plant licensees to submit annual reports specifying the quantity of each of the principal radionuclides released to unrestricted areas in liquid and airbome effluents and such other information as may.
be required by the NRC to estimate maximum potential annual radiation doses to the public. A knowledge of meteorological conditions in the vicinity of the reactor is important in providing a basis for estimating annual radiation doses resulting from radioactive materials released in airbome effluents. Accordingly, the (meteorological monitoring instrumentation serves a useful function in estimating radiation doses to the public from either routine or accidental releases of radioactive materials to the atmosphere. The licensee has proposed to relocate these provisions to the UFSAR such that future chsnges to the operation and surveillance of the meteorological monitoring instrumentation could be changed under 10 CFR 50.59.
Although the meteorological monitoring instrumentation serves a useful function as described above, it does not serve a primary protective function so as to warrant inclusion in the TS in accordance with the criteria of the final policy statement. The instrumentation does not serve to ensure that the plant is operated within the bounds of initial conditions assumed in design basis accident and transient analyses or that the plant will be operated to preclude transients or accidents. Likewise, the meteorological instrumentation does not serve as part of the primary success path of a safety sequence analysis used to demonstrate that the consequences of these events are within the appropriate acceptance criteria.
' Accordingly, the staff has concluded that the requirements for meteorological monitoring instrumentation do not meet the 10 CFR 50.36 criteria, so they may be removed from the TS and reloc&ted to the UFSAR. The limiting conditions for operation and surveillance requirements for meteorological monitoring instrumentation were not included in the latest versions of the standard technical specifications for all reactor types (including Standard Technical Specifications for Combustion Engineering Plants, NUREG-1432).
In summary, these specific instrumentation requirements are not required to be in the TS under 10 CFR 50.36 or Section 182a of the Atomic Energy Act, and are not required to obviate the possibility of an abnormal situation or event giving rise to an immediate threat to public health and safety. Further, they do not fall within any of the four criteria set forth in the Commission's Final Policy Staternent and subsequently incorporated into 10 CFR 50.36. In addition, the Staff finds that sufficient regulatory controls exist under 10 CFR 50.59 to address future changes to these requirements. Accordingly, the staff has concluded that these requirernents may be relocated from the TS to the licensee's UFSAR.
The licensee has included several changes to other TS that are affected by the relocation of the above requirements. The staff has reviewed these changes and,in light of accepting the trucation to the updated FSAR of the limiting conditions for operation and surveillance
- requirements for the subject instrumentation, finds the proposed changes to be appropriate. It I
l addition, the licensee has proposed to relocate those TS Bases affected by the relocation of the l
TS requirements. The ::taff finds the relocation of the affected TS Bases to be acceptable.
The NRC has included as a condition for the approval of this request that the relocated requirements will be included in the appropriate submittal of the updated FSAR for ANO-1 and ANO-2 in accordance with 10 CFR 50.71(e).
4.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Arkansas State official was notified of the proposed issuance of the amendment. The State official had no comment.
5.0 ENylRONMENTAL CONSIDERATION The amendments change a requirement with respect to installation or use of a u.ility component located within the restricted area as defined in 10 CFR Part 20 and change surveillance requirer.. ins. The NRC staff has &Wmined that the amendments involve no significant
!.',vesse in the amounts, and no sigr& sat change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration and there has been no public comment on such finding (62 FR 2188). Accordingly, the amendments meet the eligibility criteria for categorica! exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
6.0 [:9ECLUSION The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: W. D. Reckley Date: July 13,1998
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