ML101160135
| ML101160135 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 04/26/2010 |
| From: | V Sreenivas Plant Licensing Branch II |
| To: | Heacock D Virginia Electric & Power Co (VEPCO) |
| Sreenivas V.NRR/DORL/LPL2-1 415-2597 | |
| References | |
| TAC ME2413, TAC ME2414 | |
| Download: ML101160135 (4) | |
Text
From: Sreenivas, V Sent: Monday, April 26, 2010 10:14 AM To: 'david.heacock@dom.com' Cc: 'Tom Shaub'; 'jay.leberstien@dom.com'; 'page.kemp@dom.com'; Benton, Laray; Cotton, Karen; Kulesa, Gloria
Subject:
REQUEST FOR ADDITIONAL INFORMATION #2, REGARDING THE LICENSE AMENDMENT, NORTH ANNA, UNITS 1 AND 2, ECCS PUMP ROOM EXHAUST AIR CLEANUP SYSTEM (PREACS) TS 3.7.12 REQUEST FOR ADDITIONAL INFORMATION (RAI) FOR NORTH ANNA POWER STATIONS (NAPS)
(TAC NOS. ME2413 AND ME2414)
By letter dated September 28, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML032730468), Virginia Electric and Power Company, (the licensee) requested an amendment to Facility Operating License Nos. NPF-4 and NPF-7 for North Anna Power Station (NAPS), Units 1 and 2, respectively. The proposed change will add new conditions B and C with associated Action Statements and Completion Times to Technical Specification 3.7.12 and modify Conditions A and D of the same. These changes specifically address the filtration function of the emergency core cooling system (ECCS) pump room exhaust air cleanup system (PREACS).
Further to clarifications provided during our on-site meeting held at NRC's resident office at NAPS on April 21, 2010, the following final questions constitute additional information request related to Accident Dose.
- 1. In Attachment 1, pages 2 and 3, of the subject license amendment request, the licensee proposed the addition of Conditions B and C, and modifications to Condition D, which all state in part:
B.1.1 Verify ECCS leakage log is less than the maximum allowable unfiltered leakage.
B.1.2 Verify by field walkdown that ECCS leakage is less than the maximum allowable unfiltered leakage C.1.1 Verify ECCS leakage log is less than the maximum allowable unfiltered leakage.
C.1.2 Verify by field walkdown that ECCS leakage is less than the maximum allowable unfiltered leakage D.1.1 Verify ECCS leakage log is less than the maximum allowable unfiltered leakage.
D.1.2 Verify by field walkdown that ECCS leakage is less than the maximum allowable unfiltered leakage
Similarly, Attachment 1, page 10 of the subject license amendment request states:
In addition, the proposed change includes surveillance requirements that requires ECCS leakage operating parameters to be monitored by walking down the areas every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> in order to determine whether or not filtration capability is required (Action B.1.2). Establishing monitoring on a 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> frequency is based on operating history, which indicated that a sudden change in ECCS leakage is not expected, and the conservatisms in the design basis dose calculations.
If total ECCS leakage is equal to or greater than the maximum allowable unfiltered leakage limit then the filtration capability of ECCS PREACS is required and actions must be taken to restore Operability of the filter within seven days (Action B.2) consistent with an inoperable PREACS train for any other reason.
Please describe the methods, conditions, and/or procedures that constitute a field walkdown, and how such a walkdown remains consistent with the current licensing basis of North Anna. Specifically, if LEAKAGE is identified during the field walkdown, how will the amount of ECCS LEAKAGE present be measured and compared against the maximum allowable limits for North Anna?
In accordance with proposed required actions B.1.1, C.1.1, and D.1.1, against what particular value will the licensees personnel measure leakage against to ensure that the unfiltered ECCS leakage limit of 1700 cc/hr is not exceeded? For example, if during a field walkdown an operator measured ECCS leakage droplets in a graduated cylinder over a period of five (5) minutes, what administrative limit or value is he/she comparing their measurements against to determine rather the ECCS leakage rate is excessive and/or not during that time period?
Please provide examples and/or sample calculations where applicable.
- 2. In the subject license amendment request, the licensee stated on Page 7 of Attachment 1:Since the air within the ECCS pump rooms is exhausted by the ECCS PREACS and is aligned to the filters post-accident, a larger amount of ECCS leakage can be accommodated in these rooms. The maximum amount of ECCS leakage that can be accommodated in both the pump rooms (filtered) and remaining areas (unfiltered) is established by the assumption in the analysis (dose) of record. This relationship is shown in Figure 15.4-111 of Revision 44 of the UFSAR.
Revision 44 of the UFSAR is out dated. Revision 45, dated September 30, 2009, is the most recently updated UFSAR, and is, therefore, part of the current licensing basis for North Anna.
Please verify your parameters, conditions, and assumptions regarding the maximum amount of ECCS leakage that can be accommodated within the referenced pump rooms, as established in the consequential dose analysis of record and the currently updated version of the UFSAR (Revision 45), and other docketed information as applicable.
- 3. In the subject license amendment request, the licensee stated on Page 7 of Attachment 1:Procedures which address monitoring of ECCS leakage include provisions such that the ECCS leakage measurement will be adjusted by conservative calculation to reflect the accident conditions (i.e., higher leakage due to higher system operating pressure). Therefore, there is assurance that actual leakage during an accident will be less than or equal to the operating parameter of ECCS leakage identified prior to the accident.
Please clarify how the referenced procedures and provisions are consistent with North Annas current licensing basis (e.g. the TS definition of LEAKAGE, TS 3.7.12, TS 5.5.2, TS 5.5.4, etc), which also includes the licensees associated consequential dose analyses of record.
Please verify the procedures, provisions, conditions, and/or methods by which conservative adjustments to the ECCS leakage measurements are made, and justify how and why these calculations conservatively reflect accident conditions, in accordance with North Annas current licensing basis. Specifically, to what purpose does the adjustments to the ECCS LEAKAGE measurement serve? Do these adjustments change or affect the current licensing bases of North Anna in any way (e.g. changing the assumptions and/or inputs into the dose analysis of record, etc)?
Please provide examples and/or sample calculations where applicable.
Please submit the docketed response to these RAI's by May 10, 2010.
Docket Nos. 50-338, 50-339 for NAPS V. Sreenivas, PH.D., C.P.M.,
Project Manager, Rm.#O8F6, LPL2-1 North Anna Power Reactors, Units 1 and 2 Division of Operating Reactor Licensing-NRR (301) 415-2597, v.sreenivas@nrc.gov
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Subject:
REQUEST FOR ADDITIONAL INFORMATION #2, REGARDING THE LICENSE AMENDMENT, NORTH ANNA, UNITS 1 AND 2, ECCS PUMP ROOM EXHAUST AIR CLEANUP SYSTEM (PREACS) TS 3.7.12 Sent Date: 4/26/2010 10:14:25 AM Received Date: 4/26/2010 10:14:00 AM From: Sreenivas, V Created By: V.Sreenivas@nrc.gov Recipients:
david.heacock@dom.com ('david.heacock@dom.com')
Tracking Status: None tom.shaub@dom.com ('Tom Shaub')
Tracking Status: None jay.leberstien@dom.com ('jay.leberstien@dom.com')
Tracking Status: None page.kemp@dom.com ('page.kemp@dom.com')
Tracking Status: None Laray.Benton@nrc.gov (Benton, Laray)
Tracking Status: None Karen.Cotton@nrc.gov (Cotton, Karen)
Tracking Status: None Gloria.Kulesa@nrc.gov (Kulesa, Gloria)
Tracking Status: None Post Office:
HQCLSTR02.nrc.gov Files Size Date & Time MESSAGE 20726 4/26/2010 Options Expiration Date:
Priority: olImportanceNormal ReplyRequested: False Return Notification: False Sensitivity: olNormal Recipients received: