ML102240221
| ML102240221 | |
| Person / Time | |
|---|---|
| Site: | Humboldt Bay |
| Issue date: | 08/10/2010 |
| From: | Sokolsky D Pacific Gas & Electric Co |
| To: | John Hickman NRC/FSME/DWMEP/DURLD/RDB |
| Hickman J (301) 415-3017 | |
| References | |
| Download: ML102240221 (3) | |
Text
From:
Sokolsky, David [DDS2@PGE.COM]
Sent:
Tuesday, August 10, 2010 7:27 PM To:
Hickman, John Cc:
Roller, Paul James; Rod, Kerry; Baldwin, Thomas (DCPP); Griffin, John J; Snyder, Robert A; Albers, John P; jweismann@usecology.com; Chad Hyslop; Newey, John
Subject:
HBPP RESPONSE TO NRC QUESTION 3 Follow Up Flag:
Follow Up Flag Status:
Completed John, Below are HBPP responses to Question 3 from your July 15, 2010 email to me, including additional NRC concerns discussed during our July 29, 2010 public meeting for the HBPP Alternal Disposal Exemption Reuqest dated April 1, 2010 The concern about averaging waste in the cell appears to be about the Intruder Scenario doses from hot spots. The Intruder Scenario dose calculation uses the concentrations from HBL 003, Enclosure 1, Table 1 with no averaging for dilution by non-radioactive waste other than averaging over a single shipment. Individual shipments are expected to be reasonably homogeneous.
The below information addresses the NRC concern (that arose during discussions on Question 3) about potential driver dose from other shipments arriving at the USEI Grand View facility coincident with HBPP deliveries:
- 1. The expected dose rate in the cab from a loaded waste container (assuming max concentrations) = 4.63E-04 mR/hr. For evaluation purposes, USEI will conservatively assume that this dose rate is doubled to 9.2E-03 mR/hr due to inadvertent close proximity to a neighboring loaded container.
- 2. The expected time that a driver would be potentially exposed to another collocated load at Grandview = 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> (this estimate is conservatively estimated as it typically only requires ~ 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> (or less) for a driver to complete his evolution at USEI's Grand View facility)
- 3. Given these assumptions, the resulting additional driver dose would be 1.92E-02 mR, or an additional 8% of the estimated transit dose to the driver accumulated from HBPP to Grand View, ID.
These calculations show that the postulated doses from inadvertent exposure to a neighboring container scenario are essentially insignificant, even with conservative assumptions. Normal operations at USEI's Grand View facility would contribute far less (or even zero additional) dose
to a typical driver since the assumptions used above are not representative of USEI typical practices. To illustrate this point, we offer the following points:
- 1. Trucks that are admitted through the security access point and processed at Receiving are done so one at a time. Therefore, a driver that is currently being processed will likely never be closer to another loaded vehicle than he is to his own trailer. Therefore, dose rates expected from loads other than his own should be lower than postulated or even at regional background levels.
- 2. Typical processing time for a loaded truck at Grand View, on average, is less than one hour.
Therefore, the postulated doses above are likely overestimated by as much as a factor of 4.
David Sokolsky Supervisor of Licensing Humboldt Bay Power Plant (707)444-0801 office (707)601-6703 cell E-mail Properties Mail Envelope Properties (C1401C183BC729408A8C00FDC35D0848059BF73A)
Subject:
HBPP RESPONSE TO NRC QUESTION 3 Sent Date: 08/10/2010 7:27:01 PM Received Date: 08/10/2010 7:27:01 PM From: Sokolsky, David Created By: DDS2@PGE.COM Recipients:
John.Hickman@nrc.gov (Hickman, John)
Tracking Status: None PJR2@PGE.COM (Roller, Paul James)
Tracking Status: None KXRR@PGE.COM (Rod, Kerry)
Tracking Status: None TRB1@PGE.COM (Baldwin, Thomas (DCPP))
Tracking Status: None JJG1@PGE.COM (Griffin, John J)
Tracking Status: None R2Sp@PGE.COM (Snyder, Robert A)
Tracking Status: None JPAd@PGE.COM (Albers, John P)
Tracking Status: None jweismann@usecology.com (jweismann@usecology.com)
Tracking Status: None CHYSLOP@usecology.com (Chad Hyslop)
Tracking Status: None JMNA@PGE.COM (Newey, John)
Tracking Status: None Post Office:
exchange16.Utility.pge.com Files Size Date & Time MESSAGE 22576 08/10/2010 Options Expiration Date:
Priority: olImportanceNormal ReplyRequested: False Return Notification: False Sensitivity: olNormal Recipients received: Follow Up. Start by Wednesday, August 11, 2010. Due by Wednesday, August 11, 2010