L-25-050, Report of Facility Changes, Tests and Experiments
| ML25071A131 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 03/12/2025 |
| From: | Blair B FirstEnergy Nuclear Operating Co, Vistra Corp |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| L-25-050 | |
| Download: ML25071A131 (1) | |
Text
L-25-050 March 12, 2025 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
Subject:
Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Report of Facility Changes, Tests and Experiments I
Beaver Valley Power Station Barry N. Blair Site Vice President P.O. Box4 200 State Route 3016 Shippingport, PA 15077 724-682-5234 10 CFR 50.59(d)(2)
In accordance with 10 CFR 50.59(d)(2), Vistra Operations Company LLC hereby submits the attached Report of Facility Changes, Tests and Experiments for Beaver Valley Power Station, Unit 1 (BVPS-1). This report reflects the implemented changes, tests and experiments that were evaluated pursuant to 10 CFR 50.59 during the period of February 1, 2023 through January 31, 2025.
There are no regulatory commitments contained in this submittal. If there are any questions, or if additional information is required, please contact Jack Hicks, Senior Manager, Licensing, at (254) 897-6725 or jack.hicks@vistracorp.com.
Attachment:
Beaver Valley Power Station, Unit 1, Report of Facility Changes, Tests and Experiments cc:
NRC Region I Administrator NRC Resident Inspector NRC Project Manager Director BRP /DEP Site BRP /DEP Representative D IVE I
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VISl A O PCOM
Attachment L-25-050 Beaver Valley Power Station, Unit 1 Report of Facility Changes, Tests and Experiments Page 1 of 2
Title:
Site Boundary and Control Room Doses Following a Main Steam Line Break Based on Core Uprate and Alternative Source Term Methodology Activity
Description:
The activity is to revise the calculation that determines the airborne dose at the exclusion area boundary (EAB),
low population zone (LPZ) and control room at Beaver Valley Power Station, Unit 1 (BVPS-1) following a main steam line break (MSLB) based on core uprate and alternative source term (AST) methodology. The revision includes changes to the steaming duration, the timing of the control room envelope (CRE) purge, and offsite breathing rate and control room operator occupancy rate changes resulting due to the timeline extending past specified Regulatory Guide 1.183, Revision 0, designated values (8 and 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />). There are no changes to the dose consequence calculation methodology associated with this activity.
With an asymmetric reactor coolant system (RCS) cooldown following a MSLB outside containment, the time required to place the residual heat removal (RHR) system in service (terminating releases from the intact steam generators) and the time required to cool the RCS to below 212°F is longer than the times credited in the current MSLB dose consequence analysis. The termination of steam releases following a MSLB outside of containment could require as much as 46.4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, based on application of the most restrictive 8°F per hour cooldown rate. The slower RCS cooldown rate is to ensure that the inactive faulted loop (which is not being cooled by releasing steam) does not become uncoupled from the rest of the RCS.
As a result of this increased steaming duration, dose consequences for the control room operator and at the LPZ increase for both the pre-accident and the concurrent iodine spike cases. This evaluation addresses the increases in the LPZ and control room operator dose consequences for a MSLB outside containment.
Summary of Evaluation:
The LPZ and control room operator dose consequence increases for a MSLB outside of containment (both pre-accident iodine spike and concurrent iodine spike cases) are less than 10 percent of the margin to the applicable regulatory limit (either 10 CFR 50.67 or 10 CFR 50 Appendix A General Design Criterion 19) and are, therefore, defined as minimal. There are no MSLB dose consequence increases associated with the EAB pre-accident iodine spike and the concurrent iodine spike doses. This is because those consequences result from the worst 2-hour dose at the site boundary, which occurs from 0 to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.
The maximum dose consequence occurs in the concurrent iodine spike control room operator dose consequence, which is proposed to increase from 1.655 Roentgen equivalent man (rem) total effective dose equivalent (TEDE),
to 1.972 rem TEDE, relative to the 5 rem TEDE regulatory limit. This results in a percent of margin increase equivalent to 0.0948 or 9.5 percent of margin, which is defined as minimal according to the 10 CFR 50.59 methodology because the increase is less than 10 percent of margin. The concurrent iodine spike dose consequence for the LPZ increases from 0.0332 rem TEDE to 0.0556 rem TEDE, resulting in 0.009 or 0.9 percent of margin.
The increase in the LPZ and control room operator dose consequences for a MSLB outside containment does not meet any of the 10 CFR 50.59(c)(2) criteria; therefore, a license amendment is not required.
Attachment L-25-050 Page 2 of 2
Title:
Revise BVPS-1/2 Licensing Requirement Surveillance 3.3.3.2 for Meteorological Monitoring Instrumentation Channel Calibration Activity
Description:
An engineering change upgraded the instruments installed on the meteorological (MET) tower, which is a 500-foot guyed tower located approximately 3,600 feet northeast of BVPS-1, as described in BVPS-1 Updated Final Safety Analysis Report (UFSAR) Appendix 2A and Figure 2A.3-1. The MET system instruments are mounted on the MET tower. The system has two independent trains (primary and redundant) with instruments mounted on each of three elevations: 35 feet (ft), 150 ft, and 500 ft.
The primary instrument train consists of wind speed/direction sensors and temperature sensors mounted on the 35 ft, 150 ft, and 500 ft elevations. The redundant instrument train also consists of wind speed/direction sensors and temperature sensors mounted on the 35 ft, 150 ft, and 500 ft elevations. A precipitation gauge is mounted at ground level. Each train contains one datalogger for the primary channels and for the redundant channels.
The purpose of the MET tower is to provide inputs for the BVPS meteorological measurement program in order to calculate site atmospheric dispersion (X/Q) factors as described in more detail in BVPS-1 UFSAR Section 2.2.4 and Appendix 2A, as well as BVPS-2 UFSAR Sections 2.3.3 and 2.3.4. The program meets the requirements of Regulatory Guide 1.23, Revision 0, and Regulatory Position C.1.1 of Regulatory Guide 1.145, Revision 1. The actual methodology used to calculate such factors is not affected; the meteorological tower parameters provide inputs for such calculations.
The current BVPS-1 and BVPS-2 Licensing Requirements Manual (LRM) Surveillance 3.3.3.2 requires the channel calibration to be performed every 184 days. The new instruments do not require calibration of this frequency; therefore, the LRM Surveillance (LRS) will be revised to once every 2 years (24 months) calibration based on vendor recommendations. A new surveillance for a functional check of the instruments will be added at an annual (12 month) frequency. The functional check may be waived if a calibration is performed. A new definition of FUNCTIONAL CHECK will also be added to the LRM. The original BVPS safety evaluations only reference the Regulatory Guide in discussing the installation of the meteorological tower and the overall use of meteorological data to determine site atmospheric dispersion. No specific mention is made of calibration frequency.
The scope of this evaluation is limited to the calibration frequency of the instrument channels. Instrument replacement was performed under a separate engineering change.
Summary of Evaluation:
MET instrumentation is used to obtain information required for a valid estimation of atmospheric diffusion at the site in accordance with Regulatory Guide 1.23 Revision 0 (previously known as Safety Guide 23) to which both units at BVPS are licensed. Regulatory Guide 1.23 Section C.5 states in part instruments should be calibrated at least semiannually. The proposed change will deviate from the Regulatory Guide calibration frequency.
The MET system is independent of any plant control systems, structures, and components important to safety, and fission product barriers. It is not an accident initiator as described in the UFSAR and cannot cause an accident of a different type. The MET system has no impact on the consequences or frequency of an accident.
Data from the MET system is used as an input to dose projection in the event of a radiological release. The evaluation methodology used in the dose projection remains unchanged.
Extending the calibration interval will slightly raise the probability that an instrument may not be accurate when called upon to function; however, there is high confidence that they will maintain accuracy despite a longer calibration period. There is not a more than minimal increase in the likelihood of an occurrence of a malfunction.
The revised surveillance frequency does not meet any of the 10 CFR 50.59(c)(2) criteria; therefore, a license amendment is not required.