ML23180A222
| ML23180A222 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 06/29/2023 |
| From: | Harbor C Arizona Public Service Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| 102-08610-CDH/MSC | |
| Download: ML23180A222 (1) | |
Text
10 CFR 50.90 Cary D. Harbor Vice President Regulatory & Oversight Palo Verde Nuclear Generating Station P.O. Box 52034 Phoenix, AZ 85072 Mail Station 7602 Tel: 623.393.7953 102-08610-CDH/MSC June 29, 2023 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
Subject:
Palo Verde Nuclear Generating Station Units 1, 2, and 3 Docket Nos. STN 50-528, 50-529, and 50-530 Renewed Operating License Number NPF-41, NPF-51, and NPF-74 Application to Revise Technical Specifications (TS) 3.5.1, Safety Injection Tanks (SITs) - Operating, TS 3.5.2, Safety Injection Tanks (SITs) - Shutdown, and TS 3.6.5, Containment Air Temperature Pursuant to 10 CFR 50.90, Arizona Public Service Company (APS) is submitting a request for an amendment to the Technical Specifications (TS) for Palo Verde Nuclear Generating Station (PVNGS) Units 1, 2, and 3.
APS requests changes to modify Limiting Condition for Operation (LCO) for TS 3.5.2, Safety Injection Tanks (SITs) - Shutdown, LCO for TS 3.6.5, Containment Air Temperature, and Surveillance Requirements (SRs) 3.5.1.2 and 3.5.2.2 for TS 3.5.1, Safety Injection Tanks (SITs) - Operating, and TS 3.5.2, respectively.
This license amendment request (LAR) will revise the SIT volumes as design values expressed in cubic feet from the Loss of Coolant Accident (LOCA) analyses, with no instrument uncertainties included. Additionally, this LAR revises the containment average air temperature LCO limit to reflect the design basis accident analytical limit, without instrument uncertainty. These changes are administrative, in that the SIT design volumes and containment air temperature analytical values remain unchanged.
The enclosure provides a description and assessment of the proposed changes. to the enclosure provides the existing TS pages marked to show the proposed changes. Attachment 2 to the enclosure provides revised (re-typed) TS pages. Attachment 3 to the enclosure provides the existing TS Bases pages marked to show revised text associated with the proposed TS changes and is provided for information only.
A pre-submittal meeting for this LAR was held between APS and the Nuclear Regulatory Commission (NRC) staff on April 5, 2023. Approval of the proposed amendment is requested by June 29, 2024. Once approved, the amendment will be implemented within 90 days.
A member of the STARS Alliance, LLC Callaway
- Diablo Canyon
- Palo Verde
- Wolf Creek
102-08610-CDH/MSC ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Application to Revise Technical Specifications 3.5.1, 3.5.2 and 3.6.5 Page 2 PVNGS has determined that there are no significant hazards considerations associated with the proposed change and that the TS change qualifies for a categorical exclusion from environmental review pursuant to the provisions of 10 CFR 51.22(c)(9).
In accordance with the PVNGS Quality Assurance Program, the Plant Review Board has reviewed and approved the LAR. By copy of this letter, the LAR is being forwarded to the Arizona Department of Health Services - Bureau of Radiation Control in accordance with 10 CFR 50.91(b)(1).
No new commitments are being made to the NRC by this letter.
Should you need further information regarding this letter, please contact Matthew S.
Cox, Licensing Department Leader, at (623) 393-5753.
I declare under penalty of perjury that the foregoing is true and correct to the best of my knowledge.
Executed on: _June 29, 2023_
(Date)
Sincerely, Harbor, Cary Digitally signed by Harbor, Cary (Z16762)
(Z16762) Date: 2023.06.29 06:46:27 -07'00' CDH/MSC/cr
Enclosure:
Description and Assessment of Proposed License Amendment cc: R. J. Lewis Acting NRC Region IV Regional Administrator S. P. Lingam NRC NRR Project Manager for PVNGS L. N. Merker NRC Senior Resident Inspector for PVNGS B. D. Goretzki Arizona Department of Health Services - Bureau of Radiation Control
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT
Subject:
Application to Revise Technical Specifications (TS) 3.5.1, Safety Injection Tanks (SITs) - Operating, TS 3.5.2, Safety Injection Tanks (SITs) - Shutdown, and TS 3.6.5, Containment Air Temperature 1.0
SUMMARY
DESCRIPTION 2.0 DETAILED DESCRIPTION 2.1 Safety Injection Tank TS SRs 3.5.1.2, 3.5.2.2 and LCO 3.5.2 2.1.1 Description of the Proposed Change 2.1.2 Reason for the Proposed Change 2.2 Containment Air Temperature TS LCO 3.6.5 2.2.1 Description of the Proposed Change 2.2.2 Reason for the Proposed Change
3.0 BACKGROUND
INFORMATION 3.1 Safety Injection Tanks 3.2 Containment Air Temperature
4.0 TECHNICAL ANALYSIS
4.1 Safety Injection Tank Analysis 4.2 Containment Air Temperature Analysis
5.0 REGULATORY EVALUATION
5.1 Precedent 5.2 No Significant Hazards Consideration 5.3 Conclusion
6.0 ENVIRONMENTAL CONSIDERATION
ATTACHMENTS: : Proposed Technical Specification Changes (Mark-Up) : Revised Technical Specification Pages (Re-Typed) : Proposed Technical Specification Bases Changes (Mark-Up) - For Information Only Page i
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT 1.0
SUMMARY
DESCRIPTION In accordance with the provisions of Section 50.90 of Title 10 of the Code of Federal Regulations (10 CFR), Arizona Public Service Company (APS) is submitting a License Amendment Request (LAR) to revise the Technical Specifications (TS) for Palo Verde Nuclear Generating Station (PVNGS) Units 1, 2, and 3. The LAR would modify the following:
- 1. Surveillance requirement (SR) 3.5.1.2 for TS 3.5.1, Safety Injection Tanks (SITs) - Operating.
- 2. SR 3.5.2.2 for TS 3.5.2, Safety Injection Tanks (SITs) - Shutdown.
- 4. LCO for TS 3.6.5, Containment Air Temperature.
2.0 DETAILED DESCRIPTION 2.1 Safety Injection Tank TS SRs 3.5.1.2, 3.5.2.2 and LCO 3.5.2 2.1.1 Description of the Proposed Change The current PVNGS TS SRs 3.5.1.2 and 3.5.2.2 and LCO for TS 3.5.2, Safety Injection Tanks (SITs) - Shutdown, list the borated water volume for each SIT as tank percent level values with instrument uncertainties included. The proposed change will list the SIT volumes as design values expressed in cubic feet from the Loss of Coolant Accident (LOCA) analyses, with no instrument uncertainties included. The proposed revised sections are cited below:
TS 3.5.2, Safety Injection Tanks (SITs) - Shutdown, currently reads as:
LCO 3.5.2 Four SITs shall be OPERABLE with a borated water volume >
39% wide range indication and < 83% wide range indication; OR Three SITs shall be OPERABLE with a borated water volume >
60% wide range indication and < 83% wide range indication.
The revised wording will be, LCO 3.5.2 Four SITs shall be OPERABLE with a borated water volume >
908 cubic feet and < 2000 cubic feet; OR Three SITs shall be OPERABLE with a borated water volume >
1361 cubic feet and < 2000 cubic feet.
Page 1
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT TS SRs 3.5.1.2 and 3.5.2.2 for TS 3.5.1, Safety Injection Tanks (SITs) -
Operating, and TS 3.5.2, Safety Injection Tanks (SITs) - Shutdown, respectively, currently reads as:
SR 3.5.1.2 Verify borated water volume in each SIT is 28% narrow range and 72% narrow range.
SR 3.5.2.2 Verify borated water volume in each required SIT is:
< 83% wide range indication.
< 83% wide range indication.
The revised wording will be, SR 3.5.1.2 Verify borated water volume in each SIT is 1750 cubic feet and 1950 cubic feet.
SR 3.5.2.2 Verify borated water volume in each required SIT is:
2.1.2 Reason for the Proposed Change TS SRs 3.5.1.2 and 3.5.2.2 currently specify SIT borated water volumes in terms of SIT narrow range level (percent) and SIT wide range level (percent), respectively. LCO 3.5.2 specifies the SIT borated water volumes in terms of SIT wide range level (percent). The proposed change is to revise TS SR 3.5.1.2, TS SR 3.5.2.2, and LCO 3.5.2 to replace the current tank levels in percent with design volumes in cubic feet. The SIT borated water volume requirements in terms of tank percent level (with instrument uncertainties included) will remain available to control room operators in the Operations Modes 1, 2, 3, and 4 Surveillance Logs procedures.
This change will more accurately describe the design/analysis limit in the TS and will also allow for future revision to the surveillance procedures to specify the TS SRs 3.5.1.2 and 3.5.2.2 SIT level requirements in terms of either narrow range instrumentation percent or wide range instrumentation percent. This will provide operational flexibility, while still maintaining the current safety analyses requirements and associated SIT level limits and controls. This control would be within the licensee-controlled surveillance procedures, pursuant to 10 CFR 50.59, Changes, tests and experiments, Page 2
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT without requiring a formal license amendment. This, in turn, will allow potential PVNGS flexibility while continuing to ensure TS LCO compliance and conformance with the safety analysis.
The original PVNGS TS LCO limit for safety injection tanks was applicable in Modes 1, 2, 3, and 4 but it was divided into two Improved Technical Specifications (ITS) by license amendment (LA) 117 [Agencywide Documents Access and Management System (ADAMS) Accession Number ML021720060]. The reason for the change was stated in the APS application:
The Current Technical Specifications (CTS) 3.5.1 is applicable in Modes 1, 2, 3, and 4. The CTS requirements have been divided into two ITS Specifications. ITS 3.5.1, Safety Injection Tanks - Operating is applicable in Modes 1 and 2 and Modes 3 and 4 with pressurizer pressure 1837 psia. ITS 3.5.2, SITs - Shutdown is applicable in Modes 3 and 4 with pressurizer pressure < 1837 psia. Therefore, this is an administrative change with no impact on safety.
The focus of the original TS LCO and SR requirement was SIT volume of borated water to establish an appropriate initial condition to mitigate design basis accidents. The instrument indication was included for operator information, as the indications available to the operators are provided in percent SIT level and not in units of cubic feet.
NUREG-1024, Technical Specifications - Enhancing the Safety Impact, dated November 1983, was the starting point for a broad effort to enhance the Technical Specifications, with a particular focus on surveillance testing.
Specifically, the Task Group chapter included the following statement, in part:
The purpose of the Task Group was to identify the scope and nature of problems with current surveillance testing and to develop alternative approaches that would provide better assurance that surveillance testing did not adversely impact safety.
Specifically, NUREG-1024 included specific relevant recommendations, as follows:
Recommendation 3 The action statements should be reviewed to assure that they are designed to direct the plants to a safe plant operational mode such that public risk is minimized and that unnecessary transients and shutdowns are precluded.
Recommendation 4 The surveillance test requirements should be reviewed to assure that they do not consume plant personnel time unnecessarily or result in undue radiation exposure to plant personnel without a commensurate safety benefit in terms of minimizing public risk.
Page 3
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT Ultimately, the recommendations documented in NUREG-1024 resulted in changes to 10 CFR 50.36, Technical specifications, as documented in the Federal Registers (58 FR 39132) dated July 22, 1993, and (60 FR 36953) dated July 19, 1995. These final NRC policy statements and rulemakings were based upon SECY-86-10, Recommendations for Improving Technical Specifications, dated January 13, 1986, which contained both Recommendations for Improving Technical Specifications, NRC Technical Specifications Improvement Project, dated September 30, 1985, and Technical Specifications Improvements, Atomic Industrial Forum (AIF)
Subcommittee on Technical Specifications Improvements, dated October 1, 1985.
These documents and policy statements formed the basis for the development of the current Standard Technical Specifications, of which NUREG-1432 is the current Combustion Engineering (CE) Standard Technical Specifications (STS).
Requiring the use of only the narrow range or wide range instrument, as stated in the current SR 3.5.1.2, SR 3.5.2.2, and LCO 3.5.2, wording is inconsistent with the aforementioned NUREG-1024 recommendations as follows:
- Failure of the narrow range or wide range instrument would lead to an unnecessary mode change, pursuant to LCO Action 3.5.1, Condition D, and LCO Action 3.5.2, Condition C after 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, which is contrary to Recommendation 3, and
- Failure of the narrow range or wide range instrument could lead to containment entry to use portable instruments on the narrow range or wide range taps or perform repairs to satisfy the SR, which would be inconsistent with Recommendation 4.
Specifying the SIT level volume requirements in terms of cubic feet more closely aligns PVNGS TS with NUREG-1432, Vol. 1, Standard Technical Specifications - Combustion Engineering Plants: Specifications, Revision 5, in that analytical limits are provided in lieu of instrument inaccuracy values. In addition, other LCOs in the current PVNGS TS also list the design basis analytical limits, instead of the instrument reading with uncertainty included.
Therefore, the proposed change is consistent with the objective of the improved Technical Specifications and provides operational flexibility, while maintaining the appropriate initial conditions for accident mitigation.
2.2 Containment Air Temperature TS LCO 3.6.5 2.2.1 Description of the Proposed Change The current LCO for TS 3.6.5, Containment Air Temperature, requires the containment average air temperature shall be 117°F, which reflects temperature indication uncertainty, while in Modes 1, 2, 3, and 4. This LAR will revise the LCO limit to be 120°F, which is the design basis accident Page 4
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT analytical limit for containment average air temperature, without instrument uncertainty. The proposed revised section is cited below:
TS 3.6.5, Containment Air Temperature, currently reads as:
LCO 3.6.5 Containment average air temperature shall be 117°F.
The revised wording will be:
LCO 3.6.5 Containment average air temperature shall be 120°F.
2.2.2 Reason for the Proposed Change The original PVNGS TS LCO limit for containment average air temperature was 120°F but it was changed to 117°F by license amendment (LA) 117 (ADAMS Accession Number ML021720060). The reason for the change was stated in the APS application, in part:
The Current Technical Specifications (CTS) value of 120 degrees is used as the maximum initial temperature in various analyses for containment temperature. Having the Improved Technical Specifications (ITS) specify a value of 117 degrees Fahrenheit as the maximum temperature is conservative and results in a greater level of safety than the CTS. The ITS value for the maximum indicated containment air temperature of 117 degrees is an administrative change from the analytical maximum containment air temperature of 120 degrees Fahrenheit in the CTS.
Part of the thought process at APS, at the time, was that providing the indicated instrument value would make operations staff verification of compliance with the LCO easier from the control room.
The NRC staff safety evaluation documented the basis for this more restrictive change, to include instrument uncertainty in the LCO, as follows from page 51 of the safety evaluation for LA 117:
ITS 3.6.5 CTS LCO 3.6.1.5, containment air temperature, reduced to incorporate instrument uncertainties.
The proposed TS change would revise the maximum containment air temperature from 120°F to 117°F, and would change the related Bases. The licensee's reanalysis noted that as much as 3°F of uncertainty may exist for the instruments that monitor containment air temperature. The 120°F is the analytical value utilized as an upper bound initial condition in the containment safety analyses and that 3°F has been determined to be an appropriate plant specific value to account for instrument uncertainty. The change to the CTS is needed to ensure that the 120°F upper limit is not exceeded. This change is a result of the licensee's revised analysis which incorporated instrument uncertainties in the analysis.
Page 5
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT The staff has reviewed the licensee's proposed change and finds that the change is more restrictive and will serve to ensure that the maximum normal containment operating temperature does not exceed the upper-limit value assumed in the containment peak accident pressure and temperature safety analysis. The containment analyses assume that containment passive heat sinks are initially at a temperature of 120°F (
Reference:
[Update Final Safety Analysis Report] UFSAR Section 6.2.1.1.3). If no allowance is provided for instrument uncertainty, there is a potential to operate with a containment temperature of 123°F, in which case the containment heat sinks would not suppress the containment pressure to the extent credited in the safety analysis.
On this basis, the staff concludes that the design basis accident is properly bounded by the analyses as described in the licensee's UFSAR and the change is, therefore, acceptable.
The change performed under LA 117 was administrative in nature and did not provide actual conservatism in the containment air temperature limit, as the SR was still verifying the indicated containment air temperature of 117°F.
NUREG-1432, Vol. 1, Standard Technical Specifications - Combustion Engineering Plants: Specifications, Revision 5, lists a bracketed containment temperature LCO limit of 120°F which does not include instrument uncertainty for facilities with atmospheric containments. The TS Bases discusses the design basis accident (DBA) calculation limit of 120°F for PVNGS. In addition, other LCOs in the current PVNGS TS also list the design basis analytical limits, instead of the instrument reading with uncertainty included. Thus, the existing PVNGS LCO 3.6.5 limit does not align with the other PVNGS LCOs.
Restoring the TS LCO limit to the design basis analytical value more closely aligns the PVNGS TS 3.6.5, Containment Air Temperature, with the intent of NUREG-1432, Vol. 1. Additionally, this change provides greater consistency inside the PVNGS TSs because it aligns the TS LCO 3.6.5 with other LCOs which list the design basis analytical value as a limit.
Currently, TS SR 3.6.5.1 requires verification of the containment indicated average air temperature is within the indicated limit of 117°F based on the existing instruments uncertainty. However, the TS SR acceptance criterion could, theoretically, be established between 117°F to 120°F, should the instrument uncertainty be reduced, either by enhanced design calculations or improved instrument replacement. The proposed change to LCO 3.6.5 containment average air temperature to reflect the analytical limit, as compared to the instrument indicated limit, will allow PVNGS to control the TS SR acceptance criterion. This control would be within the licensee-controlled TS Bases and surveillance procedures, pursuant to 10 CFR 50.59, without requiring a formal license amendment. This, in turn, will allow potential PVNGS flexibility while continuing to ensure TS LCO compliance and conformance with the safety analysis.
Page 6
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT The TS Bases is also being updated such that reference to the specific temperature indicators and a requirement to use any five of these indicators is being removed. How surveillances are performed is not typically described in the TS Bases and the details on how containment air temperature is determined is maintained within Operations Modes 1, 2, 3, and 4 Surveillance Logs procedures. The TS Bases will continue to state: In order to determine the containment average air temperature, an arithmetic average is calculated using measurements taken at locations within the containment selected to provide a representative sample of the overall containment atmosphere. Current instructions within Operations Modes 1, 2, 3, and 4 Surveillance Logs procedures remain unchanged and continue to direct the use of the temperature indicators to calculate containment average air temperature to provide a representative sample.
3.0 BACKGROUND
INFORMATION 3.1 Safety Injection Tanks The functions of the four SITs are to supply water to the reactor vessel during the blowdown phase of a LOCA, to provide inventory to help accomplish the refill phase that follows thereafter, and to provide Reactor Coolant System (RCS) makeup for a small break LOCA. The SITs are pressure vessels partially filled with borated water and pressurized with nitrogen gas. The SITs are passive components, since no operator or control action is required for them to perform their function. Internal tank pressure is sufficient to discharge the contents to the RCS, if RCS pressure decreases below the SIT pressure.
The minimum volume requirement for the SITs ensures that three SITs can provide adequate inventory to reflood the core and downcomer following a LOCA. The downcomer then remains flooded until the HPSI and LPSI systems start to deliver flow. The maximum volume limit is based on maintaining an adequate gas volume to ensure proper injection and the ability of the SITs to fully discharge, as well as limiting the maximum amount of boron inventory in the SITs.
In Modes 1 and 2, and Modes 3 and 4 with pressurizer pressure 1837 psia, a minimum of 1750 cubic feet of borated water, and a maximum of 1950 cubic feet of borated water are used in the safety analyses as the volume in the SITs. To allow for instrument inaccuracy, a 28% narrow range (corresponding to 1802 cubic feet) and a 72% narrow range (corresponding to 1914 cubic feet) are specified. The analyses are based upon the cubic feet requirements; the percentage figures are provided in the LCO for operator use because the level indicators provided in the control room are marked in percentages, not in cubic feet.
In Modes 3 and 4 with pressurizer pressure less than 1837 psia, for three OPERABLE SITs, the safety analysis uses a minimum of 1361 cubic feet of borated water and a maximum of 2000 cubic feet of borated water. To allow for instrument inaccuracy, a 60% wide range level (corresponding to 1451.5 cubic feet) and a 83%
wide range level (corresponding to 1914 cubic feet) are specified. For four OPERABLE SITs, the safety analysis uses a minimum of 908 cubic feet of borated water and a maximum of 2000 cubic feet of borated water. To allow for instrument inaccuracy, a 39% wide range level (corresponding to 1029.2 cubic feet) and a 83%
wide range level (corresponding to 1914 cubic feet) are specified. The percentage Page 7
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT figures are provided in the LCO for operator use because the level indicators provided in the control room are marked in percentage, not in cubic feet.
The safety injection tank operating and shutdown volume requirements are discussed in various licensing documents described below:
UFSAR ECCS/SIT Design Basis Information From UFSAR Section 6.3, Emergency Core Cooling System, the Emergency Core Cooling System (ECCS) or Safety Injection System (SIS) is designed to provide core cooling in the unlikely event of a LOCA. The ECCS prevents significant alteration of core geometry, precludes fuel melting, limits the cladding metal-water reaction, removes the energy generated in the core, and maintains the core subcritical during the extended period of time following a LOCA.
The SIS accomplishes these functional requirements by use of redundant active and passive injection systems. The passive portion consists of pressurized SITs, which perform a one-time function to discharge their contents and reflood the core and downcomer when the RCS depressurizes following a LOCA. The active portion of the SIS consists of high-pressure and low-pressure safety injection pumps and associated valves, which function to provide continued core cooling following a LOCA. The functional requirements for the ECCS are described in the PVNGS TS, including TS 3.5.1, Safety Injection Tanks (SITs) - Operating, and TS 3.5.2, Safety Injection Tanks (SITs) - Shutdown.
Each of the four SITs is piped into a cold leg of the RCS and isolated from the RCS during normal plant operation by two check valves in series. The tank gas/water fractions, gas pressure, and outlet pipe size are selected to allow three of the four tanks to recover the core before significant clad melting or zirconium-water reaction can occur following a LOCA. The tank is equipped with narrow range and wide range level instrumentation taps as shown in Figure 1. Redundant safety-grade narrow range and wide range instrument loops provide level indications in the control room (percent level) to monitor the condition of the tanks.
Figure 1: SIT Instrumentation Layout Page 8
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT UFSAR Section 6.3 describes the ECCS performance analyses of record for the three different fuel types that are currently used in the PVNGS cores; specifically, Westinghouse standard fuel with ZIRLO cladding (CE16STD, UFSAR 6.3.3a),
Westinghouse Next Generation Fuel with Optimized ZIRLO cladding (CE16NGF, UFSAR 6.3.3b), and Framatome fuel with M5 cladding (CE16HTP, UFSAR 6.3.3c).
The ECCS performance analyses encompass a wide range of RCS break locations and sizes, including both large and small break LOCAs. The analyses also address the single failure criterion and the availability of onsite and offsite electric power systems as required by General Design Criterion (GDC) 35, Emergency Core Cooling, of 10 CFR Part 50 Appendix A.
The ECCS performance analyses of record model the SITs as follows:
- 1. For the Westinghouse CE16STD and CE16NGF fuel types, the limiting breaks that result in the closest approach to 10 CFR 50.46 acceptance criteria - that is, peak cladding temperature, maximum localized oxidation, and core-wide oxidation - are Double-Ended Guillotine breaks in the Reactor Coolant Pump Discharge leg (DEG/PD). The Westinghouse analyses credit 100 percent of the flow from three SITs to intact RCS cold legs. The remaining SIT is modeled to spill out the broken cold leg to containment.
- 2. For the Framatome CE16HTP fuel type, the limiting break for the core-wide oxidation acceptance criterion of 10 CFR 50.46 is also a DEG/PD. The limiting breaks for the peak cladding temperature and maximum localized oxidation acceptance criteria of 10 CFR 50.46 are, however, split breaks in an RCS cold leg. The treatment of guillotine and split breaks in Framatome large break LOCA analyses is described in Revision 3 of EMF-2103P-A, Realistic Large Break LOCA Methodology for Pressurized Water Reactors, dated June 2016
[referenced in TS 5.6.5, Core Operating Limits Report (COLR)]. That is, guillotine breaks are modeled similar to that described above for the Westinghouse fuel types, with the contents of one SIT spilling out the broken cold leg to containment. The Framatome split break model, however, preserves the flow path between cold leg nodes at the break plane, as noted in Section 9.0 of the topical report, and spillage at the break location will therefore vary with the size of the break.
- 3. For postulated breaks elsewhere in the RCS (that is, hot leg breaks and stuck open pressurizer safety valves), the SIT flow credited is 100 percent of four SITs because all RCS cold legs will be intact.
UFSAR Tables 6.3.3a.2-3, 6.3.3b.2-3, and 6.3.3c-1 list the system parameters and initial conditions for the large break LOCA ECCS performance break spectrum analysis for CE16STD fuel, CE16NGF fuel, and CE16HTP fuel; respectively. One of the assumed initial conditions is volume in each SIT. From these Tables, the large break LOCA analyses use a minimum SIT volume of 1750 cubic feet and a maximum SIT volume of 1950 cubic feet.
UFSAR Tables 6.3.3a.3-2, 6.3.3b.3-2, and 6.3.3c-5 list the system parameters and initial conditions for the small break LOCA ECCS performance break spectrum analysis for CE16STD fuel, CE16NGF fuel, and CE16HTP fuel; respectively. One of the assumed initial conditions is volume in each SIT as follows:
Page 9
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT
- From Table 6.3.3a.3-2 (CE16STD fuel), the initial SIT pressure is set at 200 psia (arbitrarily low) in the analysis to conservatively prevent SIT water injection. Thus, SIT volume is not relevant in this analysis.
- From UFSAR Table 6.3.3b.3-2 (CE16NGF fuel), the initial SIT pressure is set at 602 psia in the analysis. From UFSAR Table 6.3.3b.3-6, SIT water injection is credited for only the 0.075 ft2 break size (SIT injection pressure of 602 psia is reached but not credited for the 0.07 ft2 break). The analysis uses a minimum SIT volume of 1750 cubic feet and a maximum SIT volume of 1950 cubic feet.
- From UFSAR Table 6.3.3c-5 (CE16HTP fuel), the analysis uses an initial nominal SIT water volume of 1850 cubic feet.
Long Term Cooling (LTC) is initiated when the core is quenched after a LOCA and is continued until the plant is secured. The objectives of LTC are to maintain the core at safe temperature levels and to avoid the precipitation of boric acid in the core region. UFSAR Tables 6.3.3a.4-1, 6.3.3b.4-1, list the core and system parameters used in the LTC analyses for CE16STD fuel and CE16NGF fuel, respectively. One of the assumed system parameters is initial volume in each SIT. From these Tables, the LTC analyses use a maximum SIT volume of 1950 cubic feet. From UFSAR Section 6.3.3c-4, the LTC analysis performed for the CE16STD and CE16NGF fuel types bounds the CE16HTP fuel.
UFSAR Section 15.6.5, Loss-Of-Coolant Accidents, describes the PVNGS LOCA safety analyses. UFSAR Tables 15.6.5-1 and 15.6.5-2 list the radiological consequences input parameters for the small break LOCA and large break LOCA, respectively. One of the input parameters to these analyses is initial volume in each SIT. From these Tables, the radiological consequences analyses use an initial SIT volume of 1750 cubic feet.
PVNGS Basis for Current TS SR 3.5.1.2 Requirements As previously described, the relevant SIT parameter is volume (cubic feet) as this is the design value used in the ECCS performance (LOCA) and radiological consequences analyses. However, the narrow range and wide range SIT level instrumentation in the control room provides level indications in terms of tank percent. As a result, the current levels in TS SR 3.5.1.2 are based on instrumentation and control (I&C) design calculations that convert the design/analysis volumes to tank percent values for the narrow range level instrumentation.
The required tank levels in percent are determined by converting the design values in cubic feet, or analytical limits (ALs), to percent level in the tank based on tank geometry. Instrument uncertainty is then applied to establish the percent level to be specified in the TS SR. Since the current SR values include instrument uncertainty, they are indicated values rather than design/analysis values as shown in Table 1.
Page 10
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT Table 1: SR 3.5.1.2 SIT Requirements Analysis SIT Volume (AL) SIT Narrow Range (NR) Level (Actual) (Indicated)
Minimum 1750 cubic feet > 28 percent Maximum 1950 cubic feet < 72 percent PVNGS Basis for Current TS SR 3.5.2.2 Requirements The current TS SR 3.5.2.2 requirements for SIT level are based on a lower mode analysis that determines the SIT volume necessary to provide sufficient core and downcomer reflood following a postulated LOCA. From this analysis, for four Operable SITs, a minimum SIT volume of 908 cubic feet is required, assuming only three SITs inject and the volume from one SIT spills to the containment floor. For three Operable SITs, a minimum SIT volume of 1361 cubic feet is necessary, assuming only two SITs inject and the volume from the third SIT spills to the containment floor. With respect to maximum level, an Analytical Limit of 2,000 cubic feet is developed in the analysis as the maximum tank level that ensures the minimum required SIT pressure of 260 psig, with instrument inaccuracy applied, is available.
As shown, the relevant SIT parameter in this analysis is volume expressed in cubic feet; however, the narrow range and wide range SIT level instrumentation in the control room provides level indications in terms of tank percent. As a result, the required levels in TS SR 3.5.2.2 are based on I&C design calculations that convert the analysis volumes to tank percent values for the wide range level instrumentation.
The required tank levels in percent are determined by converting the design values in cubic feet, or analytical limits (ALs), to percent level in the tank based on tank geometry. Instrument uncertainty is then applied to establish the percent level to be specified in the TS SR. Since the current SR values include instrument uncertainty, they are indicated values rather than design/analysis values as shown in Table 2.
Table 2: SR 3.5.2.2 SIT Requirements Analysis SIT Volume SIT Wide Range (WR)
(AL) Level (Actual) (Indicated)
Minimum - 4 SITs 908 cubic feet > 39 percent Minimum - 3 SITs 1361 cubic feet > 60 percent Maximum 2,000 cubic feet < 83 percent 3.2 Containment Air Temperature The primary function of the containment heating, ventilation, and air conditioning (HVAC) system is to maintain containment temperature within acceptable limits for equipment and structures during all modes of operation. The containment normal cooling system consists of four 50% air cooling units (ACUs) and two electric heaters. Each ACU (HCN-A01A, B, C, and D) contains cooling coils and a fan. During operation, air is drawn pass the cooling coils by the associated fan and discharged Page 11
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT to a common distribution duct. Containment cooling is maintained via two cooling units running and two remaining in standby. The normal chilled water (WC) system provides cooling flow through the cooling coils. All four ACUs are controlled from the control room to keep containment average air temperature less than the TS indicated limit of 117°F during operation. The temperature indicators for each level in the containment building are also provided in the control room.
NUREG-1432, Vol. 2, Standard Technical Specifications - Combustion Engineering Plants: Bases, Revision 5, Section B 3.6.5, Applicable Safety Analysis, Section states, in part:
Containment average air temperature is an initial condition used in the DBA analyses that establishes the containment environmental qualification operating envelope for both pressure and temperature. The limit for containment average air temperature ensures that operation is maintained within the assumptions used in the DBA analyses for containment.
NUREG-1432, Vol. 1, Standard Technical Specifications - Combustion Engineering Plants: Specifications, Revision 5, lists the LCO 3.6.5, containment average air temperature limit as a bracketed value of 120°F. The intent of the STS is that the initial containment air temperature in the LCO be the design basis accident analytical limit for containment average air temperature.
The initial pre-accident containment air temperature of 120°F is used in the PVNGS design basis accident analyses for both LOCAs and Main Steam Line Breaks (MSLBs). However, the current PVNGS TS LCO 3.6.5 indicated limit is stated as less than or equal to 117°F instead of 120°F. The TS LCO 3.6.5 limit of 117°F has been derived to account for instrument uncertainties which ensures the analytical limit of 120°F will not be exceeded. This LAR proposes to restore the PVNGS LCO 3.6.5 value to of less than or equal to 120°F to be consistent with the intent of the STS and PVNGS design basis accident analytical limits for containment average air temperature.
PVNGS design basis calculations establish the current setpoint and uncertainty of the temperature instruments located in the containment. The function of instrument loops is to measure the containment air temperature and provide an input to the plant monitoring system for determination of containment average air temperature.
These calculations indicate that as much as 3°F uncertainty may exist for the instruments that monitor containment air temperature. This uncertainty was used to establish the TS LCO indicated limit of less than or equal to 117°F. Thus, the indicated limit of less than or equal to 117°F ensures that the design limit of 120°F will not be exceeded as an initial condition for design basis accidents.
Operation with indicated containment temperature in excess of the current LCO limit could violate an initial condition assumed in the accident analyses. The containment air temperature analytical limit of less than or equal to 120°F is discussed in various licensing documents described below:
Page 12
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT UFSAR Description for Containment Temperature Limit The PVNGS UFSAR Section 9.4.6, Containment Building, indicates that the containment requires normal air conditioning, heating, and ventilating to maintain the required temperature to ensure equipment operability, and to provide the required ventilation and control of airborne radioactivity for personnel access. The power generation design basis for containment the HVAC system is to maintain a containment ambient air temperature between 50°F and 120°F during normal plant operation to permit continuous operation of all equipment within the containment.
UFSAR Section 6, Engineered Safety Features, also describes the containment temperature analytical limit of 120°F in various Sections and Tables as mentioned below:
UFSAR Section 6.2.1.1.2.5, Containment Cooling and Ventilation Systems - During normal reactor operation the containment atmosphere is maintained below 120°F by continuous operation of the containment normal ventilation system.
UFSAR Section 6.2.1.1.1.2, Containment Internal Structures Accident Conditions, lists Table 6.2.1-3, Principal Containment Design Parameters - The containment design high mean temperature during normal operation is 120°F.
UFSAR Section 6.2.1.1.3.1.B.1, Initial Conditions and Input Data, lists Table 6.2.1-6, Initial Conditions for Containment Peak Pressure Analysis - The containment temperature (maximum normal) is 120°F.
UFSAR Section 6.2.1.1.3.6, Protection Against Severe External Loading, lists Table 6.2.1-12, Assumptions Used in Analysis of Inadvertent Containment Spray System Actuation - Initial temperature (maximum) is 120°F.
PVNGS Technical Specifications Bases 3.6.5 Requirements From TS Bases 3.6.5, Containment Air Temperature, the containment structure serves to contain radioactive material that may be released from the reactor core following a DBA. The containment average air temperature is limited during normal operation to preserve the initial conditions assumed in the accident analyses for a LOCA or MSLB. The containment average air temperature limit is derived from the input conditions used in the containment functional analyses and the containment structure external pressure analyses. This LCO ensures that initial conditions assumed in the analysis of containment response to a DBA are not violated during unit operations.
The limit for containment average air temperature ensures that operation is maintained within the assumptions used in the DBA analysis for containment. The accident analyses and evaluations considered both LOCAs and MSLBs for determining the maximum peak containment pressures and temperatures. The worst case LOCA generates larger mass and energy releases than the worst case MSLB; however, the MSLB event results in a higher peak temperature than the LOCA event. The initial pre-accident temperature inside containment was assumed to be 120°F.
The initial containment average air temperature condition of 120°F resulted in a maximum vapor temperature in containment of 405.65°F. The calculated maximum Page 13
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT temperature of the containment steel liner during the hypothetical event is approximately 244°F. The containment average air temperature limit of 120°F ensures that, in the event of an accident, the maximum design temperature for the containment steel liner, 300°F, is not exceeded. The current LCO limit of less than or equal to 117°F was derived to account for instrument inaccuracies. The indicated limit of 117°F ensures that the actual limit of 120°F will not be exceeded.
TS SR 3.6.5.1 Currently, TS SR 3.6.5.1 requires verification of the containment average air temperature is within the LCO limit to ensure that containment operation remains within the limit assumed for the containment analyses. In order to determine the containment average air temperature, an arithmetic average is calculated using measurements taken at various locations within the containment selected to provide a representative sample of the overall containment atmosphere. The Operations Modes 1, 2, 3, and 4 Surveillance Logs procedures takes the arithmetical average of temperatures of a number of containment temperature indicators. The surveillance limit of 117°F ensures that the design analytical limit of 120°F will not be exceeded as an initial condition for design basis accidents.
4.0 TECHNICAL ANALYSIS
4.1 Safety Injection Tank Analysis In Modes 1 and 2, and Modes 3 and 4 with pressurizer pressure 1837 psia, a minimum of 1750 cubic feet of borated water, and a maximum of 1950 cubic feet of borated water are used in the safety analyses as the volume in the SITs. In Modes 3 and 4 with pressurizer pressure less than 1837 psia, for three OPERABLE SITs, the safety analysis uses a minimum of 1361 cubic feet of borated water and a maximum of 2000 cubic feet of borated water. For four OPERABLE SITs, the safety analysis uses a minimum of 908 cubic feet of borated water and a maximum of 2000 cubic feet of borated water. These volume requirements list the SIT volumes as design values expressed in cubic feet from the LOCA analyses, with no instrument uncertainties included.
The proposed changes in TS LCO limit and Bases document are administrative in nature and do not change any initial conditions for the SIT volume used in the PVNGS safety analyses. The design basis accident calculations that use SIT volume analytical limits listed in Tables 1 and 2 in Section 3.0 of this submittal will be unaffected and remain valid for all analysis conditions currently established.
To ensure the design basis analytical limits will not be exceeded, the Operations Modes 1, 2, 3, and 4 Surveillance Logs procedures for TS SRs 3.5.1.2 and 3.5.2.2 will continue to use the current instrument uncertainties. Should new, more accurate instruments replace the current instruments or better uncertainty calculations be performed, any change to the SR acceptance criterion would be performed in accordance with 10 CFR 50.59.
This proposed change aligns PVNGS TS with the intent of NUREG-1432, Vol. 1, Standard Technical Specifications - Combustion Engineering Plants: Specifications, Revision 5, and ensures consistency inside PVNGS TS LCOs. In addition, the proposed change will allow APS to control the TS SR acceptance criterion within the Page 14
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT licensee-controlled surveillance procedures, pursuant to 10 CFR 50.59, without requiring a formal license amendment.
4.2 Containment Air Temperature Analysis In Modes 1, 2, 3, and 4, TS 3.6.5 requires that the containment average air temperature shall be less than or equal to 117°F. This temperature limit in the TS LCO 3.6.5 will be modified to list the design bases accident analysis initial temperature of 120°F and update the associated Bases document accordingly.
The proposed changes in TS LCO limit and Bases document are administrative in nature and do not change any initial conditions for the containment average air temperature used in the PVNGS safety analyses. The design basis accident calculations that use containment air temperature analytical limit of 120°F will be unaffected and remain valid for all analysis conditions currently established.
The PVNGS design calculations noted that as much as 3°F of uncertainty may exist for the instruments that monitor containment air temperature. To ensure the design basis analytical limit of 120°F will not be exceeded, the Operations Modes 1, 2, 3, and 4 Surveillance Logs procedures for TS SR 3.6.5.1 will continue to use the current instrument maximum average value of 117°F in order to account for the current instrument uncertainties. Should new, more accurate instruments replace the current instruments or better uncertainty calculations be performed, any change to the SR acceptance criterion would be performed in accordance with 10 CFR 50.59. Additionally, the current temperature verification methodology, described in the TS Bases for SR 3.6.5.1 and the Operations Modes 1, 2, 3, and 4 Surveillance Logs procedures will remain unchanged.
This proposed change realigns PVNGS TS with the intent of NUREG-1432, Vol. 1, Standard Technical Specifications - Combustion Engineering Plants: Specifications, Revision 5, and ensures consistency inside PVNGS TS LCOs. In addition, the proposed change will allow APS to control the TS SR acceptance criterion within the licensee-controlled TS Bases and surveillance procedures, pursuant to 10 CFR 50.59, without requiring a formal license amendment.
5.0 REGULATORY EVALUATION
5.1 Precedent This proposed administrative change more closely aligns PVNGS TS with NUREG-1432, Vol. 1, Standard Technical Specifications - Combustion Engineering Plants:
Specifications, Revision 5.
The TS for Comanche Peak Nuclear Power Plant Units 1 and 2, Amendment 156, (ADAMS Accession No. ML12067A244) for LCO 3.5.1, Four ECCS accumulators shall be OPERABLE, lists the safety analysis values for the accumulators in gallons for SR 3.5.1.2. Additionally, the TS for San Onofre Nuclear Generating Station Units 2 and 3, Amendments 135 and 124, respectively (ADAMS Accession No. ML022000194),
LCO 3.5.1, Four SITs shall be OPERABLE, listed the safety analysis values for their SITs in cubic feet for SR 3.5.1.2.
Page 15
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT Additionally, the changes performed in PVNGS TS under License Amendment 117 associated with LCO 3.6.5 (ADAMS Accession Number ML021720060) is being restored to its original value of less than or equal to 120°F.
5.2 No Significant Hazards Consideration Arizona Public Service Company (APS) is submitting a License Amendment Request (LAR) to revise the Technical Specifications (TS) for Palo Verde Nuclear Generating Station (PVNGS) Units 1, 2, and 3. The proposed amendment would modify Limiting Condition for Operation (LCO) for TS 3.5.2, Safety Injection Tanks (SITs) -
Shutdown, LCO for TS 3.6.5, Containment Air Temperature, and Surveillance Requirements (SRs) 3.5.1.2 and 3.5.2.2 for TS 3.5.1, Safety Injection Tanks (SITs)
- Operating, and TS 3.5.2, Safety Injection Tanks (SITs) - Shutdown, respectively.
Specifically, this LAR will revise the SIT volumes as design values expressed in cubic feet from the Loss of Coolant Accident (LOCA) analyses, with no instrument uncertainties included and revise the containment average air temperature LCO limit to reflect the design basis accident analytical limit, without instrument uncertainty.
APS has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, Issuance of Amendment, as discussed below:
- 1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: NO The proposed change is administrative. Modifying TS SR 3.5.1.2, SR 3.5.2.2, LCO 3.5.2, and LCO 3.6.5 aligns PVNGS TS more closely with NUREG-1024, Technical Specifications-Enhancing Safety Impact, and the NUREG-1432 Combustion Engineering Standard Technical Specifications (Vol. 1, Standard Technical Specifications - Combustion Engineering Plants: Specifications, Revision 5). The SIT volume requirements and containment air temperature design basis accident analysis analytical limits and initial conditions for accidents and modes of operation will remain unchanged. The accounting for instrument inaccuracies will continue as part of surveillance procedures. No accident analysis input values or instrument inaccuracies will change.
Therefore, the severity of the accident consequences will also not change.
Modifying TS SR 3.5.1.2, SR 3.5.2.2, LCO 3.5.2, and LCO 3.6.5 will align the PVNGS TS with other TS and allow PVNGS to control the TS surveillance within the licensee-controlled, pursuant to 10 CFR 50.59, TS Bases and procedures.
Since there is no change to the design basis analytical limits or any changes to physical equipment or operational conditions, this proposed change does not involve a significant increase in the probability or consequence of an accident previously evaluated.
Page 16
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT
- 2. Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: NO The proposed change is administrative. Modifying TS SR 3.5.1.2, SR 3.5.2.2, LCO 3.5.2, and LCO 3.6.5 aligns PVNGS TS more closely with NUREG-1024 and NUREG-1432. The SIT volume requirements and containment air temperature design basis accident analysis analytical limits and initial conditions for accidents and modes of operation will remain unchanged. No accident analysis input values, accident analysis initial conditions or instrument inaccuracies will change Since there is no change to the design basis analytical limits or any changes to physical equipment or operational conditions, there are no credible new failure mechanisms, malfunctions, or accident initiators not considered in the design and licensing basis and thus, this proposed change does not create the possibility of a new or different kind of accident than previously evaluated.
- 3. Does the proposed change involve a significant reduction in a margin of safety?
Response: NO The proposed change is administrative. Modifying TS SR 3.5.1.2, SR 3.5.2.2, LCO 3.5.2, and LCO 3.6.5 aligns PVNGS TS more closely with NUREG-1024 and NUREG-1432. The SIT volume requirements and containment air temperature design basis accident analysis analytical limits and initial conditions for accidents and modes of operation will remain unchanged. The accounting for instrument uncertainties will continue as part of surveillance procedures.
Modifying TS SR 3.5.1.2, SR 3.5.2.2, LCO 3.5.2, and LCO 3.6.5 will align the PVNGS TS with other TS and allow PVNGS to control the TS surveillance within the licensee-controlled, pursuant to 10 CFR 50.59, TS Bases and procedures.
Analysis inputs for SIT volume, containment air temperature, and analysis margin remains the same. The calculated peak containment steel liner temperature will be unaffected, as will the existing thermal margins for the containment liner.
Therefore, as there is no change to the design basis analytical limit or any change to physical equipment or operational conditions, this proposed change does not involve a significant reduction in the margin of safety.
5.3 Conclusion In conclusion, since the SIT volume and containment air temperature used for design basis analyses are unaffected by the proposed change, the ECCS performance, radiological consequences and calculated peak containment steel liner temperature will be unchanged. Therefore, APS concludes that the proposed license amendment request does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of no significant hazards consideration is justified.
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ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT
6.0 ENVIRONMENTAL CONSIDERATION
The proposed amendment is administrative in nature and does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluent that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure.
Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b),
no environment impact statement or environmental assessment need be prepared in connection with the proposed amendment.
Page 18
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT Attachment 1 Proposed Technical Specification Changes (Mark-Up)
Changed Page(s) 3.5.1-2 3.5.2-1 3.5.2-2 3.6.5-1
SITs-Operating 3.5.1 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME D. Required Action and D.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time of Condition A, B, AND or C not met.
D.2 Reduce pressurizer 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> pressure to
< 1837 psia.
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.1.1 Verify each SIT isolation valve is fully open. In accordance with the Surveillance Frequency Control Program SR 3.5.1.2 Verify borated water volume in each SIT is In accordance 1750 cubic feet 28% narrow range and 1950 with the cubic feet 72% narrow range. Surveillance Frequency Control Program SR 3.5.1.3 Verify nitrogen cover pressure in each SIT is In accordance 600 psig and 625 psig. with the Surveillance Frequency Control Program (continued)
PALO VERDE UNITS 1,2,3 3.5.1-2 AMENDMENT NO. 188, 209
SITs - Shutdown 3.5.2 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) 3.5.2 Safety Injection Tanks (SITs) - Shutdown LCO 3.5.2 Four SITs shall be OPERABLE with a borated water volume
> 908 cubic feet 39% wide range indication and < 2000 cubic feet83% wide range indication; OR Three SITS shall be OPERABLE with a borated water volume
> 1361 cubic feet 60% wide range indication and < 2000 cubic feet83% wide range indication.
APPLICABILITY: MODES 3 and 4 with pressurizer pressure < 1837 psia.
ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One required SIT A.1 Restore required SIT to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> inoperable due to boron OPERABLE status.
concentration not within limits.
OR One required SIT inoperable due to inability to verify level or pressure.
B. One required SIT B.1 Restore required SIT 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> inoperable for reasons to OPERABLE status.
other than Condition A.
C. Inoperability of the C.1 Be in MODE 5. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> required SIT was discovered but not restored while in ITS 3.5.1, "SITs Operating" OR Required Action and associated Completion Time of Condition A or B not met.
D. Two or more required D.1 Enter LCO 3.0.3. Immediately SITs inoperable.
PALO VERDE UNITS 1,2,3 3.5.2-1 AMENDMENT NO. 117, 118
SITs - Shutdown 3.5.2 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.2.1 Verify each required SIT isolation valve is fully In accordance open when pressurizer pressure is 430 psia. with the Surveillance Frequency Control Program SR 3.5.2.2 Verify borated water volume in each required In accordance SIT is: with the Surveillance
- a. For four OPERABLE SITs, > 908 cubic Frequency feet 39% wide range indication and < 2000 Control Program cubic feet 83% wide range indication.
- b. For three OPERABLE SITs, > 1361 cubic feet 60% wide range indication and < 2000 cubic feet 83% wide range indication.
SR 3.5.2.3 Verify nitrogen cover pressure in each required In accordance SIT is 260 psig and 625 psig. with the Surveillance Frequency Control Program (continued)
PALO VERDE UNITS 1,2,3 3.5.2-2 AMENDMENT NO. 117, 188
Containment Air Temperature 3.6.5 3.6 CONTAINMENT SYSTEMS 3.6.5 Containment Air Temperature LCO 3.6.5 Containment average air temperature shall be 120117°F.
APPLICABILITY: MODES 1, 2, 3, and 4.
ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Containment average A.1 Restore containment 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> air temperature not average air within limit. temperature to within limit.
B. Required Action and B.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time not AND met.
B.2 Be in MODE 5. 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.5.1 Verify containment average air temperature In accordance with is within limit. the Surveillance Frequency Control Program PALO VERDE UNITS 1,2,3 3.6.5-1 AMENDMENT NO. 117, 188
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT Attachment 2 Revised Technical Specification Changes (Re-Typed)
Changed Page(s) 3.5.1-2 3.5.2-1 3.5.2-2 3.6.5-1
SITs-Operating 3.5.1 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME D. Required Action and D.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time of Condition A, B, AND or C not met.
D.2 Reduce pressurizer 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> pressure to
< 1837 psia.
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.1.1 Verify each SIT isolation valve is fully open. In accordance with the Surveillance Frequency Control Program SR 3.5.1.2 Verify borated water volume in each SIT is In accordance 1750 cubic feet and 1950 cubic feet. with the Surveillance Frequency Control Program SR 3.5.1.3 Verify nitrogen cover pressure in each SIT is In accordance 600 psig and 625 psig. with the Surveillance Frequency Control Program (continued)
PALO VERDE UNITS 1,2,3 3.5.1-2 AMENDMENT NO. 209,
SITs - Shutdown 3.5.2 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) 3.5.2 Safety Injection Tanks (SITs) - Shutdown LCO 3.5.2 Four SITs shall be OPERABLE with a borated water volume
> 908 cubic feet and < 2000 cubic feet; OR Three SITS shall be OPERABLE with a borated water volume
> 1361 cubic feet and < 2000 cubic feet.
APPLICABILITY: MODES 3 and 4 with pressurizer pressure < 1837 psia.
ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One required SIT A.1 Restore required SIT to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> inoperable due to boron OPERABLE status.
concentration not within limits.
OR One required SIT inoperable due to inability to verify level or pressure.
B. One required SIT B.1 Restore required SIT 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> inoperable for reasons to OPERABLE status.
other than Condition A.
C. Inoperability of the C.1 Be in MODE 5. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> required SIT was discovered but not restored while in ITS 3.5.1, "SITs Operating" OR Required Action and associated Completion Time of Condition A or B not met.
D. Two or more required D.1 Enter LCO 3.0.3. Immediately SITs inoperable.
PALO VERDE UNITS 1,2,3 3.5.2-1 AMENDMENT NO. 118,
SITs - Shutdown 3.5.2 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.2.1 Verify each required SIT isolation valve is fully In accordance open when pressurizer pressure is 430 psia. with the Surveillance Frequency Control Program SR 3.5.2.2 Verify borated water volume in each required In accordance SIT is: with the
- a. For four OPERABLE SITs, > 908 cubic Surveillance feet and < 2000 cubic feet. Frequency Control Program OR
SR 3.5.2.3 Verify nitrogen cover pressure in each required In accordance SIT is 260 psig and 625 psig. with the Surveillance Frequency Control Program (continued)
PALO VERDE UNITS 1,2,3 3.5.2-2 AMENDMENT NO. 188,
Containment Air Temperature 3.6.5 3.6 CONTAINMENT SYSTEMS 3.6.5 Containment Air Temperature LCO 3.6.5 Containment average air temperature shall be 120°F.
APPLICABILITY: MODES 1, 2, 3, and 4.
ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Containment average A.1 Restore containment 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> air temperature not average air within limit. temperature to within limit.
B. Required Action and B.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time not AND met.
B.2 Be in MODE 5. 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.5.1 Verify containment average air temperature In accordance with is within limit. the Surveillance Frequency Control Program PALO VERDE UNITS 1,2,3 3.6.5-1 AMENDMENT NO. 188,
ENCLOSURE DESCRIPTION AND ASSESSMENT OF PROPOSED LICENSE AMENDMENT Attachment 3 Proposed Technical Specification Bases Changes (Mark-Up) - For Information Only Changed Page(s)
B 3.5.1-4 B 3.5.2-3 B 3.6.5-2 B 3.6.5-3
SITs - Operating B 3.5.1 BASES APPLICABLE therefore, whenever the SIT motor operated isolation valves SAFETY ANALYSES are open, power is removed from their operators and the (continued) switch is key locked open. Whenever the SIT vent valves are closed, power is removed with a keylock switch.
These precautions ensure that the SITs are available during an accident (Ref. 4). With power supplied to the valves, a single active failure could result in a valve failure, which would render one SIT unavailable for injection. If a second SIT is lost through the break, only two SITs would reach the core. Active failures that could affect the SITs would be the closure of a motor operated outlet valve or opening of a solenoid operated nitrogen vent valve, the requirement to remove power from these eliminates this failure mode.
The minimum volume requirement for the SITs ensures that three SITs can provide adequate inventory to reflood the core and downcomer following a LOCA. The downcomer then remains flooded until the HPSI and LPSI systems start to deliver flow.
The maximum volume limit is based on maintaining an adequate gas volume to ensure proper injection and the ability of the SITs to fully discharge, as well as limiting the maximum amount of boron inventory in the SITs.
A minimum of 1750 cubic feet of borated water, and a maximum of 1950 cubic feet of borated water are used in the safety analyses as the volume in the SITs. The SIT level indicators provided in the control room are marked in percentages, not in cubic feet. The required SIT volumes from the safety analyses are converted to a level percentage with instrument inaccuracies applied to enable performance of surveillance procedures.To allow for instrument inaccuracy, a 28% narrow range (corresponding to 1802 cubic feet) and a 72% narrow range (corresponding to 1914 cubic feet) are specified. The analyses are based upon the cubic feet requirements; the percentage figures are provided in the LCO for operator use because the level indicator provided in the control room is marked in percentages, not in cubic feet.
The minimum nitrogen cover pressure requirement ensures that the contained gas volume will generate discharge flow rates during injection that are consistent with those assumed in the safety analyses.
The maximum nitrogen cover pressure limit ensures that excessive amounts of gas will not be injected into the RCS after the SITs have emptied.
(continued)
PALO VERDE UNITS 1,2,3 B 3.5.1-4 REVISION 0
SITs Shutdown B 3.5.2 BASES APPLICABLE These precautions ensure that the SITs are available during an SAFETY accident (Ref. 3). With power supplied to the valves, a single ANALYSES active failure could result in a valve failure, which would render one (continued) of the required SITs unavailable for injection. If a second required SIT is lost through the break, only the remaining required SIT(s) would reach the core. Active failures that could affect the SITs would be the closure of a motor operated outlet valve or opening of a solenoid operated nitrogen vent valve, the requirement to remove power from these eliminates this failure mode. Power is removed from the SIT isolation valves and nitrogen vent valves when pressurizer pressure is 1500 psia. This is consistent with the minimum LOCA analysis pressure of 1600 psia. During operations at RCS pressure greater than 430 psia, the SIT isolation valves are procedurally locked open and motive power is removed with the breakers locked open, which is conservative with respect to SR 3.5.2.5.
The minimum volume requirement for the required SITs, assuming one SIT is not available, ensures that the SITs can provide adequate inventory to reflood the core and downcomer following a LOCA. The downcomer then remains flooded until the HPSI and LPSI systems start to deliver flow.
The maximum volume limit is based on maintaining an adequate gas volume to ensure proper injection and the ability of the SITs to fully discharge, as well as limiting the maximum amount of boron inventory in the SITs.
For three OPERABLE SITs, the safety analysis uses a minimum of 1361 cubic feet of borated water and a maximum of 2000 cubic feet of borated water. To allow for instrument inaccuracy, a 60% wide range level (corresponding to 1451.5 cubic feet) and a 83% wide range level (corresponding to 1914 cubic feet) are specified. For four OPERABLE SITs, the safety analysis uses a minimum of 908 cubic feet of borated water and a maximum of 2000 cubic feet of borated water. To allow for instrument inaccuracy, a 39% wide range level (corresponding to 1029.2 cubic feet) and a 83% wide range level (corresponding to 1914 cubic feet) are specified. The percentage figures are provided in the LCO for operator use because the level indicator provided in the control room is marked in percentage, not in cubic feet. For three OPERABLE SITs and four OPERABLE SITs, an analytical high limit of 2000 cubic feet is developed in the design analyses based on maintaining an adequate gas volume to ensure proper injection and the ability of the SITs to fully discharge. The SIT level indicators provided in the control room are marked in percentages, not in cubic feet. The required SIT volumes from the safety analyses are converted to a level percentage with instrument inaccuracies applied to enable performance of surveillance procedures.
(continued)
PALO VERDE UNITS 1,2,3 B 3.5.2-3 REVISION 66
Containment Air Temperature B 3.6.5 BASES APPLICABLE The initial containment average air temperature condition of SAFETY ANALYSES 120°F resulted in a maximum vapor temperature in (continued) containment of 405.65°F. The temperature of the containment steel liner reached approximately 244°F. The containment Average air temperature limit of 120°F ensures that, in the event of an accident, the maximum design temperature for the containment steel liner, 300°F, is not exceeded. The consequence of exceeding this design temperature may be the potential for degradation of the containment structure under accident loads.
The Technical Specification SurveillanceLCO limit of 117°F has been derived to account for instrument inaccuracies. The indicated limit of 117°F ensures that the analyticalactual limit of 120°F will not be exceeded.
Containment average air temperature satisfies Criterion 2 of 10 CFR 50.36 (c)(2)(ii).
LCO During a DBA, with an initial containment average air temperature less than or equal to the LCO temperature limit, the resultant peak accident temperature is maintained below the containment design temperature. As a result, the ability of containment to perform its function is ensured.
APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment. In MODES 5 and 6, the probability and consequences of these events are reduced due to the pressure and temperature limitations of these MODES. Therefore, maintaining containment average air temperature within the limit is not required in MODE 5 or 6.
(continued)
PALO VERDE UNITS 1,2,3 B 3.6.5-2 REVISION 1
Containment Air Temperature B 3.6.5 BASES ACTIONS A.1 When containment average air temperature is not within the limit of the LCO, it must be restored to within limit within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. This Required Action is necessary to return operation to within the bounds of the containment analysis. The 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Completion Time is acceptable considering the sensitivity of the analysis to variations in this parameter and provides sufficient time to correct minor problems.
B.1 and B.2 If the containment average air temperature cannot be restored to within its limit within the required Completion Time, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.
SURVEILLANCE SR 3.6.5.1 REQUIREMENTS Verifying that containment average air temperature is within the LCO limit ensures that containment operation remains within the limit assumed for the containment analyses. In order to determine the containment average air temperature, an arithmetic average is calculated using measurements taken at locations within the containment selected to provide a representative sample of the overall containment atmosphere. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.
The Primary containment average air temperature is determined by taking the arithmetical average of the temperatures at any five of the following locations:
- a. Nominal Elevation 85'- 0" e. Nominal Elevation 145' - 0"
- b. Nominal Elevation 85'- 0" f. Nominal Elevation 188' - 0"
- c. Nominal Elevation 126'- 0" g. Nominal Elevation 188' - 0"
- d. Nominal Elevation 126'- 0" (continued)
PALO VERDE UNITS 1,2,3 B 3.6.5-3 REVISION 72