ML093520938
| ML093520938 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 12/18/2009 |
| From: | John Hughey Plant Licensing Branch 1 |
| To: | Brian Fuller State of PA |
| Hughey J, NRR/DORL, 301-415-3204 | |
| References | |
| Download: ML093520938 (3) | |
Text
From:
Hughey, John Sent:
Friday, December 18, 2009 1:51 PM To:
Fuller, Brad A Cc:
Chernoff, Harold
Subject:
FW: Question on CAD amendment Attachments:
ML092220045.pdf; ML073170138.pdf
- Brad, Thank you for the question and comment regarding the Exelon license amendment request under review with the NRC to remove the containment atmospheric dilution (CAD) systems at Peach Bottom Units 2 and 3 (ADAMS No. ML092220045 - attached).
The CAD system is a safety grade system at Peach Bottom. However, it is no longer relied upon or credited in the plant accident analyses and this is reflected in the Peach Bottom Updated Final Safety Analysis Report.
The license amendment request would remove the requirements for the CAD system from the plant Technical Specifications (TS). Section 4.0 of the amendment request (attached) states that the CAD system will not be physically removed from the facility, but will be maintained as a support system to other equipment. However, should the NRC approve the amendment request and remove the TS requirements for the CAD system, the potential will exist for the licensee to apply the criteria of 10 CFR 50.59 and possibly physically remove the CAD system from the facility in the future.
This amendment request seeks to specifically incorporate at Peach Bottom a generically approved change to the Standard Improved Technical Specifications (NUREG 1433, Rev.
3). A model application, proposed No Significant Hazards Consideration and model Safety Evaluation (SE) were published in the Federal Register on November 21, 2007 (72FR65610). (I have attached a pdf file of the notice - ADAMS No. ML073170138.)
Section 3.1 of the model SE notes that a rule change to 10 CFR 50.44 in 2003 eliminated the requirement to maintain hydrogen control equipment for BWRs with Mark I containment designs (such as Peach Bottom). The model safety evaluation notes that the CAD system was shown to be ineffective at mitigating hydrogen releases from the more risk significant beyond design-basis accidents that could threaten primary containment integrity, and is no longer required to address a design-basis Loss Of Coolant Accident (LOCA).
While the amendment request describes that the CAD system will remain functional, primary containment atmospheric control is accomplished via the containment inerting system. The purpose of the containment inerting system is to assure that the initial concentration of O2 prior to the LOCA is maintained below the flammability limits within primary containment. This is done by maintaining the primary containment atmosphere inert with nitrogen and ensuring that no external sources of oxygen are introduced into containment as part of normal and post accident operation.
Thank you again for your comments. Please contact me at (301) 415-3204 should you have further questions or comments.
John John Hughey NRR/DORL/LPL 1-2 Peach Bottom Project Manager 301-415-3204 From: Fuller, Brad A [1]
Sent: Monday, November 23, 2009 10:09 AM To: Hughey, John
Subject:
RE: Question on CAD amendment
- John, Due to the holiday and everything I won't be in the office until Friday (12/4) so no hurry on my end.
Anyway my question is, if they're are proposing a physical change to the CAD system, then what is the change? if "physical change" includes potentially eliminating the system altogether then I would have some concern especially if CAD is safety related.
Have a great Thanksgiving.
Brad Brad Fuller l Nuclear Safety Specialist Department of Environmental Protection Rachel Carson State Office Building 400 Market Street l Harrisburg, PA 17101 Phone: 717.783.8549 l Fax: 717.783.8965 www.depweb.state.pa.us E-mail Properties Mail Envelope Properties (3D388D66E29B124A910BAC867C3A359D52E9DB5551)
Subject:
FW: Question on CAD amendment Sent Date: 12/18/2009 1:51:28 PM Received Date: 12/18/2009 1:51:00 PM From: Hughey, John Created By: John.Hughey@nrc.gov Recipients:
brfuller@state.pa.us (Fuller, Brad A)
Tracking Status: None Harold.Chernoff@nrc.gov (Chernoff, Harold)
Tracking Status: None Post Office:
HQCLSTR01.nrc.gov Files Size Date & Time MESSAGE 2069967 12/18/2009 ML092220045.pdf 1935971 ML073170138.pdf 118541 Options Expiration Date:
Priority: olImportanceNormal ReplyRequested: False Return Notification: False Sensitivity: olNormal Recipients received: