ML022970490
| ML022970490 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 10/23/2002 |
| From: | Kenyon T NRC/NRR/DRIP/RLEP |
| To: | Office of Nuclear Reactor Regulation |
| Kenyon T, NRR/DRIP/RLEP, 415-1120 | |
| References | |
| Download: ML022970490 (3) | |
Text
October 23, 2002 NOTE TO:
FROM:
SUBJECT:
Docket File Thomas J. Kenyon, Project Manager Environmental Section License Renewal and Environmental Impacts Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation CLARIFICATION TO OMAHA PUBLIC POWER DISTRICT'S (OPPD's)
RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION (RAI)
REGARDING SEVERE ACCIDENT MITIGATION ALTERNATIVES (SAMA) FOR THE FORT CALHOUN STATION UNIT 1 LICENSE RENEWAL APPLICATION During telecons on October 21, 2002, the staff requested clarification to OPPD's September 18, 2002 response to RAIs regarding SAMAs for the Fort Calhoun Station Unit 1 license renewal application. Subsequently, OPPD provided the attached e-mail from Thomas Matthew, OPPD, to Thomas Kenyon, NRC, dated October 23, 2002, to provide written clarification of this matter.
Docket No. 50-285
Attachment:
As stated
Thomas Kenyon - Responses to SAMA RAI additional questions Paie 1 1 From:
"MATTHEWS, THOMAS C" <tcmatthews2@oppd.com>
To:
"Kenyon, Tom" <TJK2@nrc.gov>
Date:
10/23/02 11:32AM
Subject:
Responses to SAMA RAI additional questions Tom Here are the SAMA RAI additional questions and the OPPD responses as discussed in telephone calls on 10/21/02.
Question In your response to RAI la, OPPD states "In all, there were a total of 89 specific review comments. Seven of these review comments/observations were felt to be significant. These items were identified for expedited resolution and were included in the plant's PRA configuration control program."
Were these inclusions reflected in the Revision 3 PRA model used in the SAMA evaluation? If not, please discuss the impact of these 7 significant items on the SAMA assessments, in particular whether any of the SAMAs studied would now be cost beneficial or whether new SAMA candidates would come into the picture.
Response
The initial SAMA assessment considered the 7 items, and it was concluded that resolution of the items would have no impact upon the SAMA assessments. Two of the items were already resolved in the Rev. 3 PRA model, which was used in the initial SAMA evaluation. Four other items identified the need for either a minor model change or increased documentation, and were dispositioned in the initial evaluation as not being significant. The final item was associated with the selection of the human factors modeling. Since FCS uses standard SAIC human factors methodology, the review comment was judged to be not significant to SAMA I Thomas Kenyon - Responses to SAMA RAI additional questions Page 11l
[ Thomas Kenvon - Resnonses to SAMA RAI additional ouestions Paae 21 assessment.
Question In your response to Ild you stated that of the 520 plant damage states (PDSs) defined in the model, 12 dominant PDSs were identified as having individual contributions of greater than 1% and in total contribute slightly more than 50% of the CDF. Please confirm that all PDSs (rather than just these 12) were used in the Level 2 and 3 analyses for purposes of determining the 50-mile population dose.
Response
The impact of all possible PDSs was considered in the 50-mile population dose calculation. This can be seen in Table 5.2-4 of Appendix 5, by noting that the release class frequencies which were used in the dose assessments also sum up to the core damage frequency. Thus, all relevant PDSs were accounted for.
Thomas C. Matthews Supervisor - Nuclear Licensing Nuclear Projects Division Fort Calhoun Station Omaha Public Power District Voice: 402.533.6938 Fax: 402.533.7291 CC:
"HACKEROTT, HAROLD A" <hhackerott@oppd.com>, "FLUEHR III, JOHN JX
<jfluehr@oppd.com>, "VAN SANT, BERNARD J" <bvansant@oppd.com>
Paoe 21