ML071280350
| ML071280350 | |
| Person / Time | |
|---|---|
| Issue date: | 03/29/2007 |
| From: | Michael Scott NRC/NRR/ADES/DSS/SSIB |
| To: | Butler J Nuclear Energy Institute |
| Scott M L, NRR/DSS/SSIB, 415-0565 | |
| References | |
| GSI-191 | |
| Download: ML071280350 (6) | |
Text
LMichael Scott -NRC STAFF REVIEW CONSIDERATIONS FOR BUFFER CHANGES-- ____- Page j From: To: Date:
Subject:
Michael Scott jcb@nei.org 03/29/2007 3:06:15 PM NRC STAFF REVIEW CONSIDERATIONS FOR BUFFER CHANGES John: Forwarded is s summary of NRC staffs thoughts on review of future buffer changes. Please contact me by return e-mail if you have any questions.
Mike CC: thomas martin;GSI-191 r ;z 00001 TMP F.-aae -1 11 I rXt~mn\G~WXflflflfl1 TMP i-~aae i Mail Envelope Properties (460COE27.9D7
- 13 : 12340)
Subject:
NRC STAFF REVIEW CONSIDERATIONS FOR BUFFER CHANGES Creation Date 03/29/2007 3:06:15 PM From: Michael Scott Created By: mls3@nrc.gov Recipients nei.org PM jcb nrc.gov OWGWPO01 .HQGWDO01 PM JPB3 CC (John Burke)PM REA CC (Ralph Architzel)
AM nrc.gov OWGWPO02.HQGWDO01 PM EXG CC (Ervin Geiger)PM JAG2 CC (Joe Golla)AM nrc.gov OWGWPO03 .HQGWDO01 PM DGC CC (David Cullison)PM nrc.gov OWGWPO04.HQGWDO01 PM ALH1 CC (Allen Hiser)PM DGH CC (Donald Harrison)MLH3 CC (Michelle Hart)PM Action Transferred Delivered Opened Opened Delivered Opened Opened Delivered Opened Delivered Opened Opened Date & Time 03/29/2007 3:06:49 03/29/2007 3:06:28 03/29/2007 3:35:51 04/03/2007 9:15:36 03/29/2007 3:06:27 03/29/2007 3:46:08 03/30/2007 7:28:29 03/29/2007 3:06:27 03/29/2007 4:22:44 03/29/2007 3:06:59 03/29/2007 3:43:25 03/29/2007 3:41:06 Ic:tmnT\GW/,O0001 .fMP P'age z II I' c:\temrAGW~OOUU1 I MP raqe L fl IL-zA~z'ss~rnz~~
--PAK CC (Paul Klein)AM TRH1 CC (Thomas Hafera)AM nrc.gov TWGWPO01 .HQGWDO01 PM JXL4 CC (John Lehning)AM SXL2 CC (Shanlai Lu)PM TOM2 CC (Thomas Martin)AM nrc.gov TWGWPO02.HQGWDOO1 PM RLT1 CC (Roberto L Torres)PM SJS2 CC (Stephen Smith)AM nrc.gov TWGWPO03.HQGWDO01 PM RRM1 CC (Ruth Reyes-Maldonado)
PM nrc.gov TWGWPO04.HQGWDO01 PM LEWI CC (Leon Whitney)PM MGY CC (Matthew Yoder)AM SMU CC (Steven Unikewicz)
AM Post Office OWGWPOO1 .HQGWDOO1 OWGWPO02.HQGWDO01 OWGWPOO3.HQGWDOO1 OWGWPOO4.HQGWDOO1 Opened Opened Delivered Opened Opened Opened Delivered Opened Opened Delivered Opened Delivered Opened Opened Opened 04/02/2007 6:19:43 04/04/2007 6:22:54 03/29/2007 3:06:29 04/02/2007 7:43:36 03/29/2007 10:25:38 03/30/2007 7:57:20 03/29/2007 3:06:27 04/11/2007 1:45:23 03/30/2007 7:51:46 03/29/2007 3:06:27 03/29/2007 3:07:05 03/29/2007 3:06:27 03/29/2007 4:00:01 03/30/2007 10:23:34 03/30/2007 8:34:26 Delivered Route nei.org 03/29/2007 3:06:28 PM nrc.gov 03/29/2007 3:06:27 PM nrc.gov 03/29/2007 3:06:27 PM nrc.gov 03/29/2007 3:06:59 PM nrc.gov I 11 c--\temD\GW 00001.TMP Fjage ý3 H c:\temD\GW~OOOO1 .TMP I-'age .~H I TWGWPO01 .HQGWDOO1 TWGWPO02.HQGWDOO1 TWGWPO03.HQGWDOO1 TWGWPO04.HQGWDO01 03/29/2007 3:06:29 PM 03/29/2007 3:06:27 PM 03/29/2007 3:06:27 PM 03/29/2007 3:06:27 PM nrc.gov nrc.gov nrc.gov nrc.gov Files Size Date & Time MESSAGE 159 03/29/2007 3:06:15 PM Review Considerations for Buffer Replacement 032907.doc 27136 3:06:14 PM 03/29/2007 Options Auto Delete: No Expiration Date: None Notify Recipients:
Yes Priority:
Standard ReplyRequested:
No Return Notification:
Send Mail Receipt when Undeliverable Concealed
Subject:
Security: To Be Delivered:
Status Tracking: No Standard Immediate Delivered
& Opened NRC Staff Review Plans for Buffer Replacement Amendments 3/29/2007 Background Several licensees are considering buffer replacements.
The NRC encourages such consideration as a potential contribution to addressing the sump clogging potential of chemical effects. Licensees and the Nuclear Energy Institute have asked the NRC staff to delineate its review considerations for these amendment requests.NRC Staff Review Considerations A change to the chemical intended to buffer the post-LOCA containment pool may impact a number of areas, including chemical effects on sump clogging, dose considerations, corrosion/stress corrosion cracking of materials, and equipment qualification.
Considerations for each of these areas are provided below.The NRC staff expects the licensee applicant to show that the buffer change will result in reduced chemical effects. Since the knowledge base of chemical effects testing continues to develop, licensees should stay current with the available information.
The amendment should demonstrate, based on currently available information, a reduction in precipitate (e.g., by providing the output results from the WCAP-16530-NP chemical model for the current and proposed buffer).The technical basis for chemical effects that demonstrates acceptable head loss and acceptable downstream component interactions assuming plant-specific debris loadings and transport will be evaluated as part of the GSI-191 resolution process, not as part of the buffer amendment process. This technical basis need not be provided in a buffer change amendment request submitted in the interim before the GL 2004-02 deadline (December 31, 2007).To address dose considerations, the licensee need only show that pH is maintained
>= 7, a demonstration sufficient for the staff to conclude that existing assumptions regarding iodine levels in the containment atmosphere remain valid.For a proposed change to a buffering agent already in use in other U.S.PWRs (sodium hydroxide, trisodium phosphate, or sodium tetraborate) and projected pH >= 7, no review/consideration of corrosion and stress corrosion cracking is needed. For proposed use of a buffer not currently in use in U.S. PWRs, licensees should consider potential impacts of corrosion and stress corrosion cracking on structures, systems, and components whose continued performance is required post-LOCA. For delayed or no introduction of buffering agents, licensees should consider corrosion and stress corrosion cracking and should also consider chemical effects from the unbuffered ECCS water prior to the introduction of the buffering agent.Licensees should verify in their submittals that equipment subject to environmental qualification remains within the analyzed EQ envelope in the presence of the proposed new buffer.
The NRC staff expects that Technical Specifications will be updated as part of buffer change amendments to indicate the name of the new buffer.