ML19295E528
| ML19295E528 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 10/18/2019 |
| From: | NRC |
| To: | NRC/NRR/DNRL |
| References | |
| Download: ML19295E528 (2) | |
Text
1 Vogtle PEmails From:
Patel, Chandu Sent:
Friday, October 18, 2019 10:47 AM To:
Chamberlain, Amy Christine; Agee, Stephanie Y.
Cc:
Vogtle PEmails; Hall, Victor Hi Stephanie and Amy, We need to have a clarification discussions on the following issues on LAR 19-003 at your convenience.
- 1. In the response to Question 2, regarding why airborne Iodine is not considered in the IRWST source term, SNC indicates that the IRWST is maintained as an acidic environment which chemically converts a portion of halogens to the elemental form (e.g. I2) and that elemental Iodine will partition across the surface of the liquid of the IRWST. Then the response states, A negligible amount of the iodine in the IRWST liquid converts to elemental I2. Additionally, partitioning across the surface of the water is minimal. There is no justification provided for why only a negligible amount of the iodine is elemental and why partitioning will be minimal. Please provide additional information on how these conclusions were reached.
- 2. The LAR states that the hydrogen igniters were tested to 57 Mrad, bounding the required 50 Mrad which considers both severe accident and 60-year operation. However, it is unclear why 50 Mrad is the required limit, as it appears inconsistent with information in the LAR and information in the UFSAR which would appear to indicate that the total integrated dose would greatly exceed 50 Mrad (the LAR indicates the normal operational dose is 22 Mrad, UFSAR Figure 3D.5-2 shows a post-accident gamma dose at one year of greater than 30 Mrad, and UFSAR Figure 3D.5-3 shows a post-accident beta dose of greater than 200 Mrad at one year). Note that this is assuming the hydrogen ignitors are qualified for 1 year following an accident, which appears consistent with information in the UFSAR. In addition, the staff notes that the beta dose alone appears to exceed 50 Mrad in less than 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> after the accident and 40 Mrad in less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, so the 50 Mrad total normal plus accident dose appears to be exceeded in only a relatively short time following the accident.
- 3. Please explain why normal operation beta dose is not considered for the equipment inside the IRWST, provided that radioactive vapors are assumed to continuously collect inside the IRWST, where the equipment is located.
Please let me know when you will be ready to discuss.
- Thanks, Chandu Patel, Senior Project Manager U.S. NRC, Office of New Reactors NRC/NRO/DNRL/LB4, Washington, DC 20555-0001 301.415.3025 MS T6C20M
Hearing Identifier:
Vogtle_COL_Docs_Public Email Number:
494 Mail Envelope Properties (SN6PR09MB3232C5D503F3A220B464132A826C0)
Subject:
Sent Date:
10/18/2019 10:46:47 AM Received Date:
10/18/2019 10:46:49 AM From:
Patel, Chandu Created By:
Chandu.Patel@nrc.gov Recipients:
"Vogtle PEmails" <Vogtle.PEmails@nrc.gov>
Tracking Status: None "Hall, Victor" <Victor.Hall@nrc.gov>
Tracking Status: None "Chamberlain, Amy Christine" <ACCHAMBE@southernco.com>
Tracking Status: None "Agee, Stephanie Y." <SYAGEE@southernco.com>
Tracking Status: None Post Office:
SN6PR09MB3232.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 2428 10/18/2019 10:46:49 AM Options Priority:
Standard Return Notification:
No Reply Requested:
No Sensitivity:
Normal Expiration Date:
Recipients Received: