Opinion ID: 216911
Heading Depth: 3
Heading Rank: 1

Heading: Citizens' Proposed Contentions

Text: On November 14, 2005, Citizens filed their first petition to intervene, containing a single contention: Exelon's application was deficient due to its failure to provide for periodic UT measurements in all levels of the drywell liner. The Board admitted a narrower version of this contention and allowed Citizens to challenge Exelon's plan for taking UT measurements in the sand bed region only, not the entire drywell liner (the Initial Contention). The Board issues the initial decision regarding the admissibility of contentions and the propriety of granting a license renewal. Thereafter, petitioners may seek further review from the NRC. In February 2006, Citizens filed a motion to add two new contentions. The first contention challenged Exelon's UT monitoring for the embedded region of the drywell, the region of the shell below the sand bed region (the Embedded Region Contention). The second contention alleged that Exelon's UT monitoring program was insufficient to detect corrosion on the interior of the drywell, as opposed to the known historical corrosion on the exterior (the Interior Corrosion Contention). After filing its initial renewal application, Exelon subsequently committed to carry out additional UT measurements. On December 9, 2005, Exelon docketed a commitment to perform a set of one-time UT measurements in the sand bed region of the drywell prior to the period of extended operation. On April 4, 2006, Exelon docketed a further commitment to complete periodic UT measurements in the sand bed region throughout the period of extended operation. And, on June 20, 2006, Exelon committed to perform additional UT measurements during the next two refueling cycles. As a result of these commitments to conduct UT measurements throughout the period of extended operation, Exelon filed a motion to dismiss Citizens' Initial Contention as moot. The Board granted Exelon's motion, but allowed Citizens to file a new contention raising a substantive challenge to Exelon's UT measurement program for the sand bed region. See In the Matter of AmerGen Energy Co., LLC (Oyster Creek Nuclear Generating Station), No. 50-0219-LR, 63 N.R.C. 737 (2006). Citizens filed their new contention on June 23, 2006, and the Board divided the contention into seven discrete challenges. [4] The Board admitted the contention in part and denied it in part. Specifically, the Board allowed Citizens' contention that the scheduled UT monitoring frequency in the sand bed region was insufficient to maintain an adequate safety margin (the Frequency Contention). See In the Matter of AmerGen Energy Co., LLC (Oyster Creek Nuclear Generating Station), No. 50-0219-LR, 64 N.R.C. 229 (2006). In their petition for review to this court, Citizens challenge the denial of only two parts of the contention: (1) that Exelon's acceptance criteria are inadequate to ensure adequate safety margins (the Acceptance Criteria Contention) and (2) that Exelon's scope of UT monitoring is insufficient to identify and test all the degraded areas in the sand bed region (the Spatial Scope Contention). [5] Acceptance criteria is the minimum required thickness for the drywell shell and is used to calculate the point where corrosion is a threat to the shell's structure. In the Acceptance Criteria Contention, Citizens argued that Exelon failed to ensure that the safety margins will be maintained throughout the period of extended operation. In the Spatial Scope Contention, Citizens asserted that the scope of UT monitoring was too narrow to allow meaningful comparison with the acceptance criteria. More specifically, Citizens insisted that the monitoring program failed to include proposed measurements of areas of the sand bed region known to be thinner than other areas.