0CAN019160, Additional Questions Associated with Notification of Full Compliance with Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis-Basis External Events
| ML16250A008 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 09/01/2016 |
| From: | Warren C Entergy Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 0CAN0191601, EA-12-049 | |
| Download: ML16250A008 (27) | |
Text
~Entergy OCAN091601 September 1, 2016 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852 Entergy Operations, Inc.
1448 S.R. 333 Russellville, AR 72802 Tel 479-858-3110 Clay C. Warren Site Vice President Arkansas Nuclear One
SUBJECT:
Additional Questions associated with the Notification of Full Compliance with NRG Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (BDBEEs)
Arkansas Nuclear One - Units 1 and 2 Docket Nos. 50-313 and 50-368 License Nos. DPR-51 and NPF-6
REFERENCES:
- 1. Entergy letter to NRG, Notification of Full Compliance with NRG Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (BDBEEs), dated January 12, 2016 (OCAN011601) (ML16014A396)
- 2. NRG letter to Entergy, NRG Order Number EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for BDBEEs, dated March 12, 2012 (OCNA031206) (ML12054A736)
Dear Sir or Madam:
Entergy Operations, Inc. (Entergy) submitted Reference 1 to document compliance with Order EA-12-049 (Reference 2) for Arkansas Nuclear One (ANO) Units 1 and 2. Reference 1 provided compliance documentation and the Final Integrated Plan (FIP) for AN0-1 and AN0-2 for strategies to maintain or restore core cooling, containment, and spent fuel pool cooling capabilities in the event of a BDBEE for the ANO units.
Subsequent to the submittal of Reference 1., the NRG requested clarifications and also requested responses to questions the staff had with respect to the Reference 1 correspondence. Attachment 1 provides clarifications of the audit open item responses (Attachment 3 of Reference 1). Attachment 2 provides the clarifications of the Fl P (Attachment 5 of Reference 1 ). Attachment 3 provides responses to the NRG questions.
This letter contains new regulatory commitments (Attachment 4). Should you have any questions regarding this submittal, please contact Stephenie Pyle at 479.858.4704.
OCAN091601 Page 2 of 2 I declare under penalty of perjury that the foregoing is true and correct; executed on September 1, 2016.
Sincere~L
~~
CCW/nbm Attachments: 1. Clarification of Audit Open Item Responses
- 2. Clarification of the Final Integrated Plan
- 3. Responses to Additional NRC Questions
- 4. List of Regulatory Commitments cc:
Mr. Kriss Kennedy Regional Administrator U.S. Nuclear Regulatory Commission, Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 NRC Senior Resident Inspector Arkansas Nuclear One P.O. Box 310 London, AR 72847 U.S. Nuclear Regulatory Commission Attn: Mr. Stephen Koenick MS 08 B1A One White Flint North 11555 Rockville Pike Rockville, MD 20852 U. S. Nuclear Regulatory Commission Attn: Mr. Peter Bamford MS 013F15M One White Flint North 11555 Rockville Pike Rockville, MD 20852 to OCAN091601 Clarification of Audit Open Item Responses to OCAN091601 Page 1 of 1 Clarification of Audit Open Item Responses This attachment provides clarifications of the audit open item responses from Attachment 3 of Reference 1 in the cover letter.
In the response to Audit Question 67, the following revision is being provided in order to correct the calculation number:
Responses to additional follow-up NRG questions have, been formally documented in CALC-ANOC-CS-15-00005 which has also been uploaded to the ePortal.
In the response to Audit Item Reference Safety Evaluation 21, the following revision is being provided in order to discuss the correct valve:
The basis for this setpoint is to protect the pressurizer code safety valve from lifting, not for boration purposes.
to OCAN091601 Clarification of the Final Integrated Plan to OCAN091601 Page 1 of 2 Clarification of the Final Integrated Plan This attachment provides clarifications of the Final Integrated Plan from Attachment 5 of Reference 1 in the cover letter.
In Section 2.3.8, the AN0-1 reactor coolant pump (RCP) controlled bleed-off (CBO) isolation time is being revised to 20 minutes to be consistent with the sequence of events timeline:
RCP CBO is isolated early following a beyond-design-basis external event (20 minutes after the event), as directed in the current station blackout procedure, which effectively terminates the major portion of seal leakage.
In Section 2.5.6 with respect to the temporary containment seal (Hawke seal) that is used during outages, the schedule 40 pipe is being revised to copper pipe including a revision to the associated internal area:
The two 3" ASTM 888 Type K Copper pipe spools have a combined internal area of 13.27 in 2
In Section 2.14, the following revision is being provided in order to clarify uninterruptible power supply (UPS) capability (docketed in NRC correspondence dated August 4, 2016 (OCAN081601):
- 3) Radio repeater systems are provided back-up power by a combination of UPS units and portable diesel generators to support long-term operation.
In Table 1 of Section 2.17, the following revisions to action items #1 and #21 are being provided in order to correct the elapsed time and connection point, respectively:
Table 1: AN0-1 Sequence of Events Timeline Action Elapsed Time Time Action Constraint Remarks I Applicability Item (hours)
Y/N The pump would connect to 21 N/A Establish FLEX SW NSRC N
blind flanges installed on the Pump service water to firewater cross-tie.
to OCAN091601 Page 2 of 2 In Table 2 of Section 2.17, the following revision to action item #22 is being provided in order to clarify the connection point:
Table 2: AN0-2 Sequence of Events Timeline Action Elapsed Time Item Time Action Constraint
- Remarks I Applicability (hours)
Y/N The pump would connect to Establish FLEX SW NSRC an adapter bolted onto the 22 N/A Pump N
top of one of the SW pump discharge strainers in the intake building.
In Table 4 referenced by Section 2.10.2, the following revision is due to the addition of the high pressure injection pumps that were discussed in Section 2.3.3:
Table 4 PWR Portable Equipment Phase 3 Use and (potential/flexibility) diverse uses List Performance Notes portable Core Containment SFP Instrumentation Accessibility Criteria equipment Two (2)
Followed High EPRI Pressure x
x template Injection Pumps
/
requirements to OCAN091601 Responses to Additional NRC Questions to OCAN091601 Page 1 of 17 Responses to Additional NRC Questions This attachment provides responses to the additional NRC questions from the April (#3, #11,
April Question 3 One of the mitigating actions for establishing containment cooling is to utilize the existing service water system (SWS). The Final Safety Analysis Report (FSAR) indicates the SWS has Seismic Category 1 and nonseismic portions. The seismic portion can be isolated from the non-seismic system by an automatically closing isolation valve.
During an extended loss of alternating current (AC) Power (ELAP) caused by a seismic event what is the failure mode of the isolation valve? If the valve fails as is, or fails open, identify the guidance for repowering/closing the isolation valves.
Phases 1 and 2 do not require the SWS for containment cooling. In Phase 3, all seismically qualified SWS piping may be used to support containment integrity. Both the AN0-1 and AN0-2 SWSs contain seismic and non-seismic piping. The non-seismic piping in each system may be isolated by valves located in the seismic portions of the SWS manually or by motor-operated valves powered from engineered safety features (ESF) busses. Note that in Phase 3, power would be provided to the ESF busses. In Phase 3, CFSG-102, "Phase Ill National Strategic Alliance for FLEX Emergency Response Center (NSRC) Equipment Staging and Installation Guideline," provides guidance for staging and installation of Phase 3 NSRC equipment including 4160 Volt AC (VAC) diesel generators, water treatment system equipment, mobile boration equipment, and various pumps. In addition, the Technical Support Center (TSC) would be fully staffed in Phase 3. As such, there is not a FLEX Support Guideline (FSG) to direct repowering/closing of the isolation valves, as the TSC would coordinate re-establishing the SWS and direct isolation of the non-seismic portions of the SWS piping.
April Question 11 The NRC staff requests environmental qualification (EQ) temperature and pressure profiles for AN0-1 and AN0-2 showing limiting EQ electrical equipment temperature and pressure profiles and analyzed containment ELAP temperature and pressure profiles for the entire ELAP duration. (Provide supporting basis for SE-29 response.)
/
As described below, it is demonstrated through evaluation of the EQ testing and associated analysis that the electrical equipment located inside containment being credited for use in response to a beyond-design-basis external event (BDBEE) would operate in an ELAP environment and would remain functional during the projected BDBEE ELAP mission time.
Removing multiple conservatisms from the MAAP calculations and assuming a BDBEE occurs in a Mode 5 mid-loop scenario (with the pressurizer manway providing the only form of venting) leads to theoretical containment failure (Reference "Case 2" discussed in CALC-13-E-0005-02 and CALC-14-E-0002-01). However, that analysis was provided to demonstrate that "containment venting or other measures to reduce containment pressure is necessary in order to prevent conditions that cause pressure to exceed the containment failure pressure limit."
Therefore, this evaluation assumes the practical scenario of a BDBEE occurring during Modes 1-4 (Reference "Case 1" discussed in CALC-13-E-0005-02 and CALC-14-E-0002-01) and the FLEX venting and cooling strategies implemented thereafter.
to OCAN091601 Page 2 of 17 For AN0-1, CALC-13-E-0005-02 AN0-1 Modular Accident Analysis Program (MAAP)
Containment Analysis for BDBEE, concludes that in Modes 1-4, Containment would reach a maximum temperature of 215.8°F at 120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br /> and a maximum pressure of 23.7 psia at 120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br />. As stated in Appendix A of NES-13, the ANO EQ equipment inside of the AN0-1 reactor building has been evaluated to withstand a peak temperature of 283.9°F and a peak pressure of 53.96 psig (68.65 psia). Therefore, the design threshold bounds the expected peak FLEX temperature and pressure in AN0-1.
For AN0-2, CALC-14-E-0002-01 AN0-2 FLEX MAAP4 Containment Analysis, concludes that in Modes 1-4, containment would reach a maximum temperature of 257.6°F within 120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br /> and a maximum pressure of 21.9 psia at 120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br />. As stated in Appendix B of NES-13, the ANO EQ equipment inside of the AN0-2 containment has been evaluated to withstand a peak temperature of 285°F and a peak pressure of 57.6 psig (72.29 psia). Therefore, the design threshold bounds the expected peak FLEX temperature and pressure in AN0-2. However, further discussion regarding the exposure of equipment to elevated temperatures and pressures for extended periods of time is merited.
The evaluated time period of 120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br /> (five days) is adequate for the BDBEE scenario as the FLEX strategy provides guidance for establishing containment cooling during Phase 3, with the necessary equipment delivered prior to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> following the start of the event. As the equipment would be delivered prior to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, it is reasonable to assume that it could be placed into service by 120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br />. The Phase 3 equipment for both units includes pumps capable of being tied into the respective unit's SWS to allow for cooling flow to the containment/reactor building fan coolers. Phase 3 generators for each unit have been adequately sized to support operation of one train of containment/reactor building fan coolers for the respective unit. One train of fan coolers for each unit is adequate to remove the decay heat generated days into the event, given one train can remove necessary containment/reactor building heat loads in design basis accident conditions.
During an ELAP event, certain instruments (e.g., transmitters in containment) are required to maintain the FLEX strategies. According to Nuclear Energy Institute (NEI) 12-06, the following instrumentation parameters must be maintained:
Steam Generator (SG) Pressure SG Level Reactor Coolant System (RCS) pressure RCS Temperature Containment Pressure Spent Fuel Pool (SFP) Level Any additional parameters that are needed in order to support key actions, or to indicate imminent or actual core damage.2 of CALC-13-E-0005-14, AN0-1 FLEX Battery Load Shed Calculation, describes the instrumentation required to support FLEX at AN0-1, and a list of those instruments located in the reactor building is provided in Table 1 below. Instruments from AN0-1 Red Train and AN0-1 Green Train, the primary and alternate trains utilized in the AN0-1 FLEX strategy, respectively, are included in Table 1. Note the SG pressure transmitters for AN0-1 are located outside containment (Ref. M-206); therefore, no EQ analysis is required.
to OCAN091601 Page 3 of 17.2 of CALC-14-E-0002-07, AN0-2 FLEX Battery Load Shed Calculation, describes the instrumentation required to support FLEX at AN0-2, and a list of those instruments located in containment is provided in Table 2 below. Instruments from AN0-2 Red Train and AN0-2 Green Train, the alternate and primary trains utilized in the AN0-2 FLEX strategy, respectively, as well as direct current (DC)-operated motor-operated valves (MOVs) and solenoid operated valves (SOVs), are provided in Table 2.
SFP level instrumentation was installed per Engineering Change (EC) 44046 and EC 48348 for AN0-1 and AN0-2, respectively. None of the SFP level instrumentation is located inside the containment/reactor building; therefore, it is not included in the evaluation below.
Although the station batteries and load shed strategies allow for monitoring of all critical parameters discussed in Supplement 14 of OG-12-515 (PA-PSC-0965) issued by the Pressurized Water Reactor (PWR) Owners Group (PWROG), that document also includes guidance for instrument prioritization. For example, RCS hot leg temperature is not required if core exit thermocouples (CETs) are available, RCS cold leg temperature is not required if SG pressure is available, and emergency feedwater (EFW) flow is not required if wide range SG level is available. Furthermore, reactor vessel level is a backup indicator of RCS inventory (Pressurizer Level is considered primary). Therefore, alternate instrumentation is not included in the tables below, consistent with FLEX Support Guidelines 1 FSG-007 and 2FSG-007, which support critical instrument readings using Fluke Process Meters during loss of DC power.
Table 1 - AN0-1 Containment Electrical Equipment Train Parameter/Description Tag Number Mfr.
Model No.
EQRA SG Pressure PT-2618A Rosemount 1153GB9 N/A (outside containment)
PT-2667A Rosemount 1153GB9 N/A
~
LT-2620 Rosemount 1154DP5RB V43-003 Cl1 E SG Level LT-2669 Rosemount 1154DP5RB V43-003 s
c RCS Pressure PT-1042 Rosemount 1154GP9RB V43-003
"(ij 1--
- Multiple, Type K Thermocouple "O
RCS Temperature Babcock &
Q)
TE-1157 PN: 1238530-003 or V52-001 a:
(CETs)
Wilcox Co (typical) 5042559-003 Containment Pressure PT-2405 Rosemount 1153AD6RB V43-001 Pressurizer Level LT-1001 Rosemount 1154HP5RB V43-003 SG Pressure PT-2618B Rosemount 1153GB9 N/A (outside containment)
PT-2667B Rosemount 1153GB9 N/A LT-2624 Rosemount 1154DP5RB V43-003 c
SG Level
"(ij LT-2673 Rosemount 1154DP5RB V43-003 1--
c RCS Pressure PT-1041 Rosemount 1154GP9RB V43-003 Q)
Q)
- Multiple, C!J RCS Temperature Babcock &
Type K Thermocouple TE-1156 PN: 1238530-003 or V52-001 (CETs)
(typical)
Wilcox Co 5042559-003 Containment Pressure PT-2406 Rosemount 1153AD6RB V43-001 Pressurizer Level LT-1002 Rosemount 1154HP5RB V43-003 to OCAN091601 Page 4 of 17 Table 2 - AN0-2 Containment Electrical Equipment Train Parameter/Description Tag Number Mfr.
Model No.
SG Pressure 2PT-1041-1 Rosemount 1154GP9RB (outside containment) 2PT-1141-1 Rosemount 1154GP9RB 2LT-1079-1 Rosemount 1154DP5RB SG Level 2LT-1179-1 Rosemount 1154DP5RB RCS Pressure 2PT-4624-1 Rosemount 1154GP9RB
~
Multiple, 2NE-1 Westinghouse Cll RCS Temperature (typical)
(formerly DWG 310-0101 E
Combustion (ICI Assembly) s Engineering) c
- Bendix, 10-607596,
"(ii ICI Cable Assembly 2GEN-1038 Combustion 10-607597, f--
"O Engineering 16-24-00180 (I) a:
Containment Pressure 2PT-5605-1 Rosemount 1153AD7RB Pressurizer Level 2LT-4627-1 Rosemount 1154HP5RB Motor Operated Valve 2CV-4698-1 Limitorque SMB-00-10 Solenoid Operated Valve 2SV-4668-1 Target Rock 97AA-001-1 2TE-4610-1 Weed Instrument N9004S-1B RCS Hot Leg Co Inc Temperature 2TE-4710-1 Weed Instrument N9004S-1B Co Inc SG Pressure 2PT-1041-2 Rosemount 1154GP9RB (outside containment) 2PT-1141-2 Rosemount 1154GP9RB 2LT-1079-2 Rosemount 1154DP5RB SG Level 2LT-1179-2 Rosemount 1154DP5RB RCS Pressure 2PT-4624-2 Rosemount 1154GP9RB
~
- Multiple, Westinghouse Cll RCS Temperature 2NE-12 (formerly DWG 310-0101 E
(typical)
Combustion
- s (ICI Assembly)
Engineering) c
- Bendix, 10-607596,
"(ii ICI Cable Assembly 2GEN-1038 Combustion 10-607597, f--
"O Engineering 16-24-00180 (I) a:
Containment Pressure 2PT-5606-2 Rosemount 1153AD7RB Pressurizer Level 2LT-4627-2 Rosemount 1154HP5RB Motor Operated Valve 2CV-4740-2 Limitorque SMB-0-15 Solenoid Operated Valve 2SV-4668-2 Target Rock 97AA-001-1 2TE-4610-2 Weed Instrument N9004S-1B RCS Hot Leg Co Inc Temperature 2TE-4710-2 Weed Instrument N9004S-1B Co Inc EQRA V43-003 V43-003 V43-003 V43-003 V43-003 V13-002 V13-001 V43-001 V43-003 V33-005 V46-001 V49-002 V49-002 V43-003 V43-003 V43-003 V43-003 V43-003 V13-002 V13-001 V43-001 V43-003 V33-005 V46-001 V49-002 V49-002 to OCAN091601 Page 5 of 17 Figures 1 and 2, for AN0-1 and AN0-2, respectively, represent the EQ equipment testing profiles from the Environmental Qualification Report Assessment (EQRA) documents referenced in Tables 1 and 2 and simulated in CALC-88-EQ-0007-01. Those testing profiles are plotted against the BDBEE ELAP profiles determined in CALC-13-E-0005-02 and CALC-14-E-0002-01, similar to the existing EQ evaluations for loss-of-coolant accident (LOCA) profiles contained in CALC-88-EQ-0007-01. Note that two test curves were included in CALC-88-EQ-0007-01 for the Rosemount 11530 and 1154 transmitters. For the purposes of this evaluation, only the most conservative test curve was considered.
u..
0 -
Figure 1 - AN0-1 ELAP Profile vs. Equipment Test Profiles AN0-1 ELAP Temp Profile (CALC-13-E-0005-02)
CET (EQRA V52-001)
Rosemount 1154 (EQRA V43-003)
Rose 1530 (EQRA V43 001) 0 -+-~~~~.__.._._.~~~~~-'-t--~~~~~f--~~~~'-'-t-~~~~~
0.001 0.01 0.1 Hours 10 100 to OCAN091601 Page 6 of 17 Figure 2 - AN0-2 ELAP Profile vs. Equipment Test Profiles 400
+-c,_,,_~~-fl-~-l----',,,._ __ ~~~~~+"4At1/u."1::i.w.<+--~~~~~~~~
Rosemount 1154 (EQRA 43-003) 350
~ 300 RCS Hot Leg {V49-002)
DCSOV (EQRA V46-001)
-+-~-t-~~~~~~~~~~EQ~R_A_V_33_~_0~
5 ~(_EQ~R_A_V_
l3_-0_0~
l)~~~~+~~~~
AN0-2 ELAP Rose. v
- 11530 Temp Profile (EQRA V43-001) 100 -+-~~~~~~~~~~~~~~~~~~~~~~~~~~~~-
(CALC-14-E-0002-01) 0 -+-~~~~~+--~~~~_._....~~~~~
.......... ~~~~~-'-+---~+--~~~.....,
0.001 0.01 0.1 1
Hours 10 100 As demonstrated in Figures 1 and 2, the testing performed on the electrical equipment addressed by this evaluation do not bound the BDBEE ELAP conditions due to the extended high temperature duration except for the AN0-2 RCS hot leg (V49-002) instrumentation.
Further analysis is provided below using the Arrhenius methodology to determine equivalent degradation for temperature profile comparisons.
Note pressure profiles are not analyzed using the Arrhenius equation. Although they are plotted along with the temperature profiles in CALC-88-EQ-0007-01, Section 4.2.1 of that calculation states that:
Equipment subjected to a greater than required peak pressure under saturated conditions can be considered qualified, due to the fact that the long term presence of a slight pressure should not affect any long term operation. Therefore, total graphical envelopment for the entire duration of the test profile over the required profiles is not a significant concern and need not be addressed any further than the above discussion.
This evaluation takes the position that the equipment qualification testing profiles found to be acceptable for the LOCA profiles analyzed in CALC-88-EQ-0007-01 based on peak pressure are also acceptable for BDBEE ELAP profiles because the peak pressure is much lower than the acceptable LOCA profiles, as shown in Figures 3 and 4.
to OCAN091601 Page 7 of 17 Figure 3 - AN0-1 ELAP Pressure vs. LOCA Pressure Profiles ANO-lLOCA
'"bO Pressure Profile
- - 40 -t-~~~~~-------,--
(CA
_L_C-8~
8--EQ--000
~-
7-0
-l~)~~+-~~~~~~~~~~
en c. -
~ 30 -+--~~~~---~~~~~~~~~~---~~~~~~~~
- J en en CV
... 20 -t-~~~-+~~~~~~~~~~~~-+1----~~~~~~-
- o.
AN0-1 ELAP Pressure Profile 10 -t-~~--~~-,-~~~~~~~~~~~~~~~,--~~~-
(CALC-13-E-0005-02) 0 ~-------....._."""""~'-ft..!~-""-'l'"-""-'""-"-=-""'-"'-J:F-=:..::1_--'--L.LLL.1..Lf--L-'--.LL.l..l..J..4~-'--'-Li...L.LL~
0.0001 0.001 0.01 o.1Hours1 10 100 Figure 4 - AN0-2 ELAP Pressure vs. LOCA Pressure Profiles
'"bO Pressure Profile
- - 40 -r-~~~~-.-~~~-
(CA~
LC-8--E_
Q-_
0_
00 1)~~~~~~~~~~~-
en c. -
~ 30 -t-~~~-1-~~~~~~~~~~~....+-~~~~~~~~~-
- J en en CV
... 20 -t-~~---~~~~~~~~~~~~~~~~~~--~~~-
- 0.
AN0-2 ELAP Pressure Profile 10 -t---,~~~~~~~~~~~~~~~~~~~~~~~~-
(CALC-14-E-0002-01) 10 100 to OCAN091601 Page 8 of 17 EQUIVALENT DEGRADATION Since the nonmetallic materials used in the construction of the electrical equipment follow an Arrhenius relationship, requirements at one time and temperature can be transferred to another set of time-temperature coordinates using the relationship below, similar to the Arrhenius methodology discussed in Section 4.3 of CALC-88-EQ-0007-01.
ts Ts ta Ta exp()
k
=
=
=
=
=
=
=
service time service temperature (K) aging (test) time aging (test) temperature (K) exponential function with base e apparent activation energy (eV), a property of the reaction Boltzmann's Constant (8.617 x 1 O" eV/K)
A time-temperature equivalency can be derived to verify that the test conditions exceed the plant postulated ELAP containment conditions, including the post-accident phase. Using the equation above, the entire set of temperature parameters given for the ELAP containment temperature conditions (see Figures 1 and 2) can be transferred to an equivalent time at a reference temperature of 120°F. Similarly, CALC-88-EQ-0007-01 employed the lowest activation energy used in the construction of the equipment in conjunction with the test temperature profiles (see Figures 1 and 2) to determine the total equivalent time at 120°F for the equipment. The equivalent times for the equipment (previously determined by CALC-88-EQ-0007-01) and the ELAP profiles (determined specifically for this evaluation) are presented in Table 3.
Table 3 - Temperature Equivalency Results Ref.
Activation Test Profile AN0-1 ELAP AN0-2 ELAP Description EQRA#
Energy (eV)
Equivalent Profile Equivalent Profile Equivalent Time at 120°F Time at 120°F Time at 120°F DCMOV V33-005 0.93 1616 days 353 days 1214 days Rosemount V43-001 0.78 930 days 177 days 498 days 11530 Rosemount V43-003 0.78 2162 days 177 days 498 days 1154 DCSOV V46-001 0.95 4821 days 387 days 1368 days AN0-2 CET (lncore Instrument V13-002 0.98 5238 days N/A 1636 days (ICI)
Assembly)
AN0-2 CET (ICI Cable V13-001 1.23 3391 days N/A 7297 days Assembly)
AN0-1 CET V52-001 1.05 21126 days 616 days N/A to OCAN091601 Page 9 of 17 Thus, using the Arrhenius method, it is demonstrated that the vendor's qualification testing exposed the nonmetallic materials to a greater thermal degradation than the postulated ELAP as a result of a BDBEE for all equipment listed in Table 3 except for the AN0-2 CET ICI Cable Assembly (EQRA V13-001 ). The AN0-2 RCS hot leg temperature can be used in lieu of the AN0-2 CET instrumentation (Reference Supplement 14 of OG-12-515 (PA-PSC-0965)). As shown in Figure 2 without the need to use the Arrhenius method, the test profile for the AN0-2 RCS hot leg instrumentation bounds the AN0-2 ELAP profile; therefore, the subject equipment is qualified for the postulated BDBEE ELAP 120-hour (five-day) profile.
Table 4 demonstrates, using the Arrhenius method and vendor test profiles from CALC-88-EQ-0007-01, that the vendor's qualification testing for all cable assemblies, penetration assemblies, connections, and terminations inside the AN0-1 reactor building and AN0-2 containment exposed the nonmetallic materials to a greater thermal degradation than the postulated ELAP as a result of a BDBEE. Therefore, the cables, penetration assemblies, connections and terminations associated with the instrumentation credited for use in response to a BDBEE are qualified. Note that the AN0-2 CET ICI Cable Assembly (EQRA V13-001) is not listed in Table 4 because it was evaluated in Table 3. Also note that the equipment listed in Table 4 is not included in Figures 1 and 2.
Table 4 - Temperature Equivalency Results for Cable Assemblies, Penetration Assemblies, Connections, and Terminations inside ANO Units 1 & 2 Containment Activation Test Profile AN0-1 ELAP AN0-2 ELAP Description EQRA Energy Equivalent Profile Profile No.
(eV)
Time at 120°F Equivalent Equivalent Time Time at 120°F at 120°F Amphenol SAMS Electrical Penetration V04-001 0.34 157 days 24 days 37 days Assembly - Power Amphenol SAMS Electrical Penetration V04-002 0.34 157 days 24 days 37 days Assembly-Instrumentation Anaconda Instrumentation Cable, V05-001 1.22 1.36E+05 days 1357 days 6872 days FR-EP Insulation Anaconda Power and V05-002 1.6 4.23E+06 days 8027 days 67751 days Control Cable Anaconda Instrumentation Cable, V05-003 1.6 4.95E+06 days 8027 days 67751 days EPR Insulation BIW Instrumentation, Control and Power V10-001 1.14 4686 days 935 days 4255 days Cable Buchanon Terminal Blocks - Model V11-002 0.95 5951 days 387 days 1368 days 0200/0500 Series Conax Multi-Pin V14-004 1.57 5.99E+06 days 6973 days 56513 days Connectors to OCAN091601 Page 10 of 17 Description Conax Electrical
- Penetration Assemblies (AN0-1)
Conax Electrical Conductor Seal Assembly Conax Low Voltage Instrumentation Feedthrough/Adapter Module Assembly Conax Coaxial!Triaxial Feedthrough Module Conax Feedthrough Module Eaton Instrumentation Cable GE Terminal Blocks -
Model EB-25 and EB-5 NAMCO Model EC210 1/2" Quick Disconnector Okonite 5kV Power Cable Okonite 2kV Power Cable Okonite 600V Power and Control Cable Okonite Power, Control and Instrumentation Cable Okonite T95/No. 35 Tape Splices Raychem Flamtrol Instrumentation Cable Raychem NJRT Splice Repair Kit Raychem Cable Splices EQRA No.*
V14-005 V14-006 V14-008 V14-009 V14-010 V19-001 V29-002 V37-007 V38-001 V38-002 V38-003 V38-004 V38-005 V40-001 V40-002 V40-003 Test Profile AN0-1 ELAP AN0-2 ELAP Activation Profile Profile Energy Equivalent Equivalent Equivalent Time (eV)
Time at 120°F Time at 120°F at 120°F 1.04 2217 days 588 days N/A 3.91 2.34E+ 16 days 5.12E+08 days 1.19E+ 11 days 3.91 4.02E+ 16 days 5.12E+08 days 1.19E+ 11 days 3.91 6.77E+16 days 5.12E+08 days 1.19E+ 11 days 3.91 2.48E+17 days 5.12E+08 days 1.19E+ 11 days 1.41 5.20E+05 days 3294 days 21526 days 1.82 1.09E+08 days 22615 days 257148 days 0.8 3042 days 194 days 560 days 1.03 7.33E+04 days 561 days 2204 days 1.03 7.17E+04 days 561 days 2204 days 1.03 (V38 7.33E+04 days 561 days 2204 days Item 15) 1.24 (V38 6.45E+04 days 1489 days 7748 days Item 22) 1.03 7.43E+04 days 561 days 2204 days 1.03 3323 days 561 days 2204 days 0.91 1.16E+04 days 322 days 1078 days 1.29 3.62E+05 days 1880 days 10460 days 1.29 98920 days 1880 days 10460 days to OCAN091601 Page 11 of 17 Description Rockbestos Coaxial Cable Rockbestos Firewall Ill SIS and Control Cable Rockbestos Power and Control Cable Rockbestos Power,
- Control, Instrumentation, and Thermocouple Cable Weed Dow Corning DC 3145 Silicone Sealant
{RTV)
Brand-Rex Instrumentation/Coaxial Cable Brand-Rex Power and Control Cable AIW Instrumentation Cable AIW Power and Control Cable EGS Quick Disconnectors EGS Grayboot Connectors EGS 600 Volt Tape Splices EGS Conduit Seals NAMCo Thread Sealant EQRA No.
V42-001 V42-002 V42-003 V42-004 V49-003 V55-001 V55-002 V58-001 V58-002 V61-001 V61-002 V61-003 V61-005 V37-004 Activation Test Profile AN0-1 ELAP AN0-2 ELAP Profile Profile Energy Equivalent Equivalent Equivalent Time (eV)
Time at 120°F Time at 120°F at 120°F 2.75 1.03E+ 11 days 1.89E+06 days 7.82E+07 days 1.35 1.95E+05 days 2488 days 15002 days 1.49 1.46E+06 days 4791 days 34863 days 1.34 4.34E+05 days 2375 days 14126 days 1.95 6.40E+07 days 41793 days 567379 days 1.37 1.24E+06 days 2732 days 16920 days 1.37 1.52E+06 days 2732 days 16920 days 1.3 1.19E+05 days 1970 days 11108 days 1.28 1.19E+05 days 1795 days 9851 days 1.05 1.08E+04 days 616 days 2484 days 0.92 9606 days 337 days 1144 days 1.14 3.43E+04 days 935 days 4255 days 2.29 1.13E+09 days
- 2. 10E+05 days 4.55E+06 days 0.63 2202 days 89 days 205 days In conclusion, it has been demonstrated through evaluation of the environmental qualification testing and associated analysis that the containment electrical equipment being credited for use in response to a BDBEE would operate in an ELAP environment.
to OCAN091601 Page 12 of 17 April Question 13 Per the ANO Final Integrated Plan (FIP), the connections for qualified condensate storage tank (QCST) fill (connections and isolation valves) are in the annulus between the shield wall and the tank. For flooding conditions will those connections be used to fill the QCST, and if so, are the connections/valves accessible?
The connections and isolation valves between the QCST shield wall and the QCST shell can be used to fill the QCST. The hoses would be connected prior to the onset of a flood and the valves would be accessible using T-handle reach rods. The connection of the hoses by CFSG-006 and installation of the T-handle reach rods are directed by Model Work Order (WO) #402438 prior to the onset of a site flood. Model WO #402438 is initiated by AN0-1 a,nd AN0-2 natural emergencies procedures OP-1203.025 and OP-2202.008, respectively.
April Question 14 For the "hardened makeup" connections to the AN0-1 and AN0-2 SFPs, the connections are as follows: (1) AN0-1 SFP "hardened makeup" connects to SFP cooler outlet drain SF-1037, (2) AN0-2 "hardened makeup" connects to the SW system. The NRC staff understands both of these connections are made in the respective unit's auxiliary buildings. Please indicate the seismic classification of the systems (AN0-1, SFP cooling and AN0-2, SW) at each connection point.
SF-1037 is located on line HCC-12-6". Line HCC-12-6" is not seismic class 1 pipe; however, CALC-89-E-0098-01 provided an analysis of this piping and concluded that the pipe withstands a maximum earthquake and maintains its pressure boundary. Calculation CALC-89-E-0098-01, Revision 000, adequately qualifies the AN0-1 SFP piping required for SFP hardened makeup and satisfies the definition of robust in NEI 12-06. EC 44047 markup to calculation CALC-89-E-0098-01 demonstrates that the existing pipe supports are qualified for maximum earthquake loading to code allowables and are considered seismically robust per NEI 12-06.
The AN0-2 SFP hardened connection is located in a seismic portion of the SWS.
August Question 1 For both units, when the term RCS temperature is referred to in the FIP and in FLEX procedures, to which specific location(s) in RCS is it referring? Because RCS loop temperature may not be available under analyzed ELAP conditions, would core exit thermocouple indication be used? If CETs are used, please further clarify how thermocouple locations would be selected or whether an average value (if available during ELAP) would be used? Or would SG pressure be used to infer cold leg temperature as long as natural circulation is maintained? Or is it referring to an RCS average temperature?
RCS loop temperature would be available under analyzed ELAP conditions as natural circulation is maintained to remove decay heat. The RCS temperature indication that is available and would be utilized is the hot leg temperature indications. This temperature is indicative of the core outlet temperature and is the highest RCS temperature and controls the RCS saturation pressure following pressurizer cooldown or emptying.
to OCAN091601 Page 13 of 17 August Question 3 What is the basis for concluding that the SGs can tolerate being fed with borated water from the borated water storage tank (BWST) and should preferentially be fed with this borated water rather than unborated raw water? This information was previously requested in AQ-67.
As discussed in the previous AQ-67 responses, there are two SG decay heat removal scenarios. One scenario is with wind missile damage to the QCST and one is without wind missile damage. For the wind missile event, an analysis was performed to demonstrate sufficient inventory is available from the damaged QCST to allow time to switch the turbine-driven EFW suction source from the QCST to Fire Pump P-68. This switchover occurs within four hours. For the non-wind missile scenario, the QCST is undamaged and provides SG feed inventory for approximately seven hours. The longer term feed source for SG injection during a non-wind event is the Emergency Cooling Pond (ECP). In a seismic event, the fire pump and fire header are not credited as neither the pump nor piping are seismically designed; therefore, portable pumps and hoses are used to provide the SG feed source. The seven hours (minimum) available from the QCST may be insufficient to establish a feed source from the ECP. To ensure sufficient time is available to establish the ECP supply, the BWST can be gravity drained to the QCST. Combining the capacity of the QCST and BWST allows up to 25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> to establish the ECP supply source. Therefore, the borated water from the BWST is not fed preferentially to unborated raw water but is used as an interim source until the ECP supply is established. Once the ECP supply is established, the further use of the BWST inventory for SG feed is not required. Procedure FDS-001 and FDS-002 will be revised to stop the BWST gravity drain and establish the ECP as the feed source as soon as the ECP supply source is established. The use of borated water as a temporary interim feed source for the SGs is acceptable as discussed below.
The water in the BWST is of high quality and produced from demineralized water, similar to the condensate storage tank (CST) and QCST inventory except for the dissolved boric acid.
Therefore, the minimal effect on SG heat transfer caused by mineral plateout as evaluated in CALC-13-E-0005-03, Once-Through SG Heat Transfer Capability using ECP or Lake Water for EFW Makeup, and CALC-14-E-0002-02, AN0-2 FLEX SG Degraded Heat Transfer Analysis, would be even more insignificant due to the very low level of dissolved mineral and suspended solids.
The other potential concern affecting SG heat transfer would be developing a concentration of boric acid where boron precipitation would occur. CALC-13-E-0005-30, FLEX BWST Gravity Drain to QCSTforShort-Term Makeup (Table 5: BWST-QCST Gravity Drain Calculation Results), shows BWST level at 396.03 feet when gravity drain begins at seven hours. At 25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> the BWST level is 371.91 feet, or a decrease of 24.12 feet. The BWST contains 9,756 gals/ft; therefore, the volume of borated water supplied to QCST and then the SGs is 235,315 gallons. Approximately half this volume is supplied to each unit and since there are two SGs per unit, approximately 60,000 gallons are supplied to each SG. On AN0-1, FDS-001, Unit 1 Extended Loss of AC Power, recovers SG level to 300-340" if subcooling is adequate, otherwise level is recovered to 370-41 O". The minimum SG level maximizes boron concentration; therefore, 300" is used to determine concentration. CALC-82-D-2086;.01, Volume of CST T-418 Requiring Tornado Missile Protection, determined the SG's volume to be 26.86 gals/in in the tube region. This provides a SG inventory of 26.86 gals/in
- 300 inches =
8,058 gallons. To perform a simplified concentration determination, the 60,000 gallons to OCAN091601 Page 14 of 17 provided to the SG from the BWST is assumed to be concentrated to 8,058 gallons with no credit for the water pre-existing in the SGs or in the QCST. Assuming maximum BWST concentration of 2670 parts per million (ppm), the concentrated solution would be approximately (2670 ppm* 60,000 gals)/ 8,058 gals= 19,880 ppm.
19,880 ppm is 19.880 g of boron/liter and given the atomic weight of boron is 10.8, the solution has a molarity (M) of approximately 1.84. SRNL-STl-2011-00578, Literature Review of Boric Acid Solubility Data provides a solubility graph that shows 1.84M boric acid remains soluble at a minimum temperature of approximately 130°F. Therefore, boric acid precipitation is not a concern in SG heat transfer. Even if asymmetric cooling is assumed such that one SG would receive all the feedwater from the BWST, the concentration would still be less than 3.7M boric acid and would remain soluble at a minimum temperature of approximately 194°F. Therefore, heat transfer using BWST water as feed for the SGs is acceptable as the cooldown target for AN0-1 and AN0-2 is 350°F. Subsequently, the plant is switched from SG cooling long before these minimum temperatures for boron solubility are approached.
The other concern with a boric acid solution is the degradation that the solution can have on
, plant materials. In this scenario with the BWST being drained to the QCST, major components exposed to the boric acid solution are carbon steel pumps, valves, and pipe from the QCST to the SGs, the steel and nickel alloy components in the SGs, and the carbon steel steam lines from the SGs to the atmospheric dump valves and EFW pump turbines. The SG tubes are nickel alloy and not subject to corrosion in the projected boric acid solution; therefore, significant corrosion of the SG tubes is not a concern. The inherent thickness of the SG shell
, removes the loss of the pressure boundary function from being a concern during the timing, temperature, and pressure of this scenario. Cleaning, testing, and evaluation of the SGs would be required prior to returning the plant to normal operation.
The carbon steel steam lines from the SGs could experience a small amount of boric acid carryover in the steam. The amount of carryover would be minimal as the steam flow is low due to the amount of heat being removed when the plant is shutdown verses at 100% power.
The temperature of the steam lines begins at over 500°F, however, the RCS and secondary systems are cooled to 350°F within 19 hours2.199074e-4 days <br />0.00528 hours <br />3.141534e-5 weeks <br />7.2295e-6 months <br />. With the minimal carryover and corrosion rates discussed below, corrosion of the steam lines is not a pressure boundary concern for the time period when the BWST is being used for.SG feed.
The carbon steel pumps, valves, and pipe from the QCST to the SGs are exposed to, *
-2300 ppm boric acid solution after the flushing of the QCST water is completed. The positive aspect of this scenario is that the temperature in these components would be dictated by the normal ambient temperature of the BWST. With the low solution temperature and corrosion rates discussed below, corrosion of the feedwater lines is not a pressure boundary concern for the time period when the BWST is being used for SG feed.
Carbon steel corrosion in aerated water with 2500 ppm boric acid (as boron) from Boric Acid Corrosion Guidebook, Revision 1 : Managing Boric Acid Corrosion Issues at PWR Power Stations, Electric Power Research Institute, 2001, Product ID 1000975.
Temperature (°F)
Corrosion Rate (in/yr) 70 0.002 100 0.007 140 0.015 500 0.24 to OCAN091601 Page 15 of 17 August Question 5 FLEX procedures FDS-001/002 (Attachment 6, Page 3) include a statement to the effect that, after the AN0-1 cooldown is complete at about 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br />, charging flow would be re-aligned to AN0-2. However, these statements appear in conflict to analysis for AN0-1 in CN-SEE-11-13-4 (as well as confirmatory analysis performed by the NRC staff), which indicates that the AN0-1 RCS cooldown may not be completed until approximately 19-20 hours into the ELAP event. As such, for a couple of hours following the planned initiation of flow to AN0-2 starting at 17.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> into the ELAP event, it is not clear how adequate flow will be provided to both AN0-1 and AN0-2. Specifically, considering the existing FLEX procedures, the capacity of a single AN0-2 charging pump does not appear sufficient to fulfill the stated net flow assumptions to both units (35 gallons per minute (gpm) to AN0-1 during its cooldown and 20 gpm to AN0-2at17.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />) that are specified in the FIP. This conflict could potentially be resolved in a number of ways, including (1) expediting the cooldown for AN0-1, (2) delaying RCS makeup to AN0-2, or (3) demonstrating that the available flow can be shared between units during this time such that adequate flow is supplied to both, or that sufficient margin exists in the available AN0-1 pressurizer inventory for this time. Please discuss your strategy for ensuring adequate flow to both units from 17.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> into the event until the AN0-1 cooldown is completed and clarify if any changes are necessary to the mitigating strategy, implementation procedures, or analysis.
WCAP-17601-P, Revision 1, "RCS Response to the Extended Loss of AC Power Event for Westinghouse, Combustion Engineering and Babcock & Wilcox (B&W) Nuclear Steam Supply System Designs," January 13, 2013, forms the basis for determining the required RCS inventory to maintain primary natural circulation, which is the acceptance criterion to which this analysis is evaluated.
Section 5.3.3.1.1.3 of WCAP-17601-P, Revision 1, provides the generic B&W plant response to a loss of AC power. For the lowered-loop units like AN0-1, the pressurizer empties at about 30,000 seconds (8.33 hours3.819444e-4 days <br />0.00917 hours <br />5.456349e-5 weeks <br />1.25565e-5 months <br />). Shortly thereafter, the lowered-loop design loses natural circulation. Based on the generic WCAP-17601-P, Revision 1, the volumetric loss of RCS liquid must remain less than the available post-trip pressurizer liquid volume in order to maintain long-term heat removal by natural circulation. As such, the margin to loss of natural circulation may be estimated by comparing the aggregate decrease in RCS liquid inventory with the post-trip pressurizer liquid inventory of 500 ft.
This 500 ft3 is equivalent to the 37 40 gallons shown as the initial starting point for CN-SEE-11-13-4, Figure 5.1-6. This figure then plots the pressurizer liquid inventory assuming a nine gpm leak rate, 35 gpm makeup rate, and a 20°F/hour RCS cooldown rate.
An AN0-2 charging pump utilized for AN0-1 makeup provides a flow of 44 gpm or an excess of nine gpm over the makeup rate assumed in developing CN-SEE-11-13-4 Figure 5.1-6. The AN0-2 charging pump makeup rate of 44 gpm results in the pressurizer being filled more quickly than the time assumed in CN-SEE-11-13-4 Figure 5.1-6.
AN0-1 Borated Water Requirements table from CALC-ANOC-ME-13-00001 shows a required makeup flow required to recover AN0-1 RCS inventory is 27,300 gallons. Assuming a 44 gpm charging pump makeup rate, 27,300 gallons would be injected within 10.34 hours3.935185e-4 days <br />0.00944 hours <br />5.621693e-5 weeks <br />1.2937e-5 months <br /> to OCAN091601 Page 16 of 17 (27,300 gallons/44 gpm/60 minutes/hour). Since the injection begins at six hours, the required RCS makeup for AN0-1 is complete at 16.34 hours3.935185e-4 days <br />0.00944 hours <br />5.621693e-5 weeks <br />1.2937e-5 months <br />. The extra water is accumulated in the AN0-1 pressurizer by a higher level being available before the RCS cooldown is complete.
Subsequently pressurizer level would lower as the cooldown continues.
Since the required makeup is injected at 16.34 hours3.935185e-4 days <br />0.00944 hours <br />5.621693e-5 weeks <br />1.2937e-5 months <br />, the following table demonstrates the pressurizer inventory over the RCS cooldown period assuming RCS makeup is stopped at 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br /> and leakage continues at nine gpm.
Volume in Excess Time (Makeup Pressurizer makeup flow Volume in assumed assuming a (9 gpm till Pressurizer for following start 20°F/hr cooldown 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br />) and 20°F/hr of RCS rate deficit flow cooldown rate cooldown at (CN-SEE-11-13-4, (-35 gpm after plus excess Pressurizer 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />)
Figure 5.1-6) 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br />) makeup Level Temperature (Hours)
(Gallons)
(Gallons)
(Gallons)
(Inches)
(oF) 8 3740 0
3740 82 570 9
2850 540 3390 67 550 10 2300 1080 3380 67 530 11 1900 1620 3520 73 510 12 1700 2160 3860 87 490 13 1600 2700 4300 105 470 14 1650 3240 4890 130 450 15 1800 3780 5580 159 430 16 2000 4320 6320 190 410 17 2350 4860 7170 226 390 18 2700 2760 5460 154 370 19 3250 660 3910 89 350 The pressurizer High Level alarm is 275" (8330 gallons) and Low Level alarm is 55" (3100 gallons); therefore, this strategy supports using a 20°F/hour cooldown rate and stopping the charging pump makeup to AN0-1 at 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br /> to support aligning makeup flow to AN0-2 at 17.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />.
In actuality, as discussed in Question 4, the RCP seal leak rates are lower than those assumed in the Westinghouse analysis. Therefore, the post-event pressurizer level would be higher than that analyzed and pressurizer level would recover more quickly than the eight hours shown on CN-SEE-11-13-4 Figure 5.1-6. FDS-001 will be revised to allow starting cooldown early if pressurizer level is recovered. In addition, the excess flow would be greater than the nine gpm (44 gpm - 35 gpm) assumed in the above table, and the deficit flow following stopping of the charging pump would be less. Therefore, a greater volume would be available in the pressurizer at 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br /> to support any remaining cooldown.
to OCAN091601 Page 17 of 17 August Question 6 The FIP description for AN0-1 identifies the analysis in Section 5.3.3.1.1.1 of WCAP-17601-P as the basis for demonstrating adequate shutdown margin. However, the calculation in WCAP-17601-P does not appear adequate for a number of reasons, including its (1) not modeling the expected RCS temperature behavior, (2) considering an upper bound RCS leakage, (3) lacking documentation of the reactivity parameters modeled in the simulation, and (4) lacking justification for the applicability of the parameters to AN0-1. The FIP also mentions a plant-specific analysis in calculation CN-SEE-11-13-4. However, although this calculation appears to contain potential RCS boron concentrations, it does not appear in itself to provide a basis for determining that AN0-1 will have adequate shutdown margin during the ELAP event. As a result, it is not clear to the NRC staff that AN0-1 would have adequate shutdown margin under ELAP conditions if the planned mitigating strategy were implemented. Please provide a revised shutdown margin analysis that complies with the positions in the PWROG's boric acid mixing white paper and the corresponding NRC staff endorsement letter that demonstrates and adequately documents that AN0-1 would have adequate shutdown margin based upon the implementation of its ELAP mitigating strategy.
CALC-13-E-0005-55, Unit 1 FLEX Reactivity Calculation, assumes that there is no RCS pump seal leakage. This results in a bounding case for both reactivity control and determining if letdown needs to be established. In the case of reactivity control, any leakage would result in a smaller RCS volume at the time of borated water addition and therefore, would result in higher mixed boron ~oncentration. For determining if letdown needs to be established, the no leakage assumption minimizes the volume space for a borated water addition.
This calculation is performed using Cycle 25 physics parameters for a shutdown margin of 1.5% and a RCS temperature of 300°F. Additionally the end-of-life (EOL) concentration of boron is assumed to be zero ppm. This results in a conservative calculation with margin above the 1.0% shutdown margin and the planned cooldown to 350°F, making this calculation suitable for future cycles.
The buildup and decay of xenon post reactor shutdown from the event is ignored in the calculation due to the strategy needed to assure that RCS inventory is maintained prior to initiating cooldown at approximately six hours from the beginning of the BDBEE prior to the peak xenon reactivity. Boration is initiated at six hours and requires approximately one hour at the beginning-of-life and less than three hours at EOL. Therefore, assuming the cooldown starts at eight hours as planned, the boration is completed and one hour of mixing has occurred before RCS temperature is below 500°F. As such, it is conservative to assume a xenon-free condition.
to OCAN091601 List of Regulatory Commitments to OCAN091601 Page 1 of 1 List of Regulatory Commitments The following table identifies those actions committed to by Entergy Operations, Inc. in this document. Any other statements in this submittal are provided for information purposes and are not considered to be regulatory commitments.
TYPE (Check One)
SCHEDULED COMMITMENT ONE-COMPLETION TIME CONTINUING DATE ACTION COMPLIANCE (If Required)
Procedure FDS-001 and FDS-002 will be revised to stop the borated water storage tank gravity drain and establish the emergency cooling pond (ECP) as the x
November 17, 2016 feed source as soon as the ECP supply source is established. (From August Question 3)
FDS-001 will be revised to allow starting cooldown early if pressurizer level is x
November 17, 2016 recovered. (From August Question 5)