Licensee Position. The licensee established a position that accessible interior surfaces of the RRVCH stud holes did not require a surface examination. The licensee position was based on Code Interpretation III-1-77-162 (Reference 1), which states in part, that drilled holes are not considered to be material form surfaces and the requirement for examination of holes (if any) resides in NX-4000 and NX-5000. The licensee concluded that the re-examination of machined surfaces as discussed in NB-4121.3 did not apply to the accessible interior surfaces of the flange stud holes because they were not material form surfaces. Staff Guidance and Regulatory Evaluation Reference 2 provides the NRC guidance on interpretations to Section III of the ASME Code. Specifically, if inspectors identify Code issues that result in a disagreement with the licensee, or if an official Code Interpretation is identified by an inspector that appears to conflict or is inconsistent with NRC requirements, the item should be sent via TIA to NRR for guidance and interpretation. Further, Reference 2 states that the ASME Code Interpretations are not incorporated into the Code of Federal Regulations; and therefore, the NRC is not bound by these interpretations. In this case, the licensee has applied wording “material form surfaces” from Reference 1 to exclude re-examination of machined surfaces formed during boring of the RRVCH flange holes. The licensee’s application of this interpretation appears to conflict with the 1989 edition of the ASME Code Section III NB-4121.3 requirement to re-examine machined surfaces of pressure boundary materials.
Licensee Position. Pacific Gas and Electric evaluated the new seismic information against the LTSP 84th percentile deterministic spectrum (a margin analysis to the Hosgri design basis). Pacific Gas and Electric stated that further review against the seismic qualification basis was not needed because the new predicted vibratory ground motions were bounded by the LTSP spectrum, which was based on the seismic source that could produce the maximum vibratory ground motion at the Diablo Canyon site (Hosgri Event). The licensee concluded that the new seismic information was therefore neither a nonconforming nor an unanalyzed condition. The licensee based these conclusions on three factors documented in Notification 50086062, Task 30:
Licensee Position. The doses due to (1) tritium evaporation from the SDSP and (2) tritium seepage from the SDSP to the unrestricted area (in the location called Nancy’s Creek) do not need to be included in the annual dose assessment in Attachment 7 of the ARERR. The total curies released do not need to be included in the release summations in Attachment 2 of the ARERR. The curies, volume released, and dose were not included because those releases are “…not part of the pathway for designed releases from the plant.”
Licensee Position. The NSCW is OPERABLE when the tower return header control switch is in the OPEN BYPASS position. This position is explained in detail in the licensee letter to the NRC dated February 2, 2009, Agencywide Document Access and Management System (XXXXX) Accession No.
Licensee Position. In response to a request from regional staff, the licensee provided their position on these issues in writing. A detailed description of the licensee’s position is provided in the licensee’s White Paper (Reference 1).
Licensee Position. Since first being presented with this issue in July 2008, the licensee’s engineering evaluations have led them to several positions. These positions have included that it is not preconditioning and that it is acceptable preconditioning. The licensee has benchmarked several other licensees’ pressure switch testing methodologies and has not reached a consensus on the preconditioning question. The licensee’s current position is that the issue is potentially a generic industry issue and should be addressed as such in regulatory space. Applicable Regulatory Position: The limited regulatory guidance on the topic of preconditioning resides primarily in Information Notice 97-16, “Preconditioning of Plant Structures, Systems, and Components Before ASME Code Inservice Testing of Technical Specification Surveillance Testing” and Inspection Manual Chapter 9900, “Maintenance – Preconditioning of Structures, Systems and Components Before Determining Operability.” The current pressure switch testing methodology affects approximately 30 pressure switches, which are relied upon to initiate technical specification required safety functions. These technical specification required functions include:
Licensee Position. The licensee’s position, as described in “Licensing Bases for Prairie Island Nuclear Generating Plant Turbine Building Internal Flooding,” dated July 16, 2010 (XXXXX Accession No. ML102100198) is that water sources from the pipe that suffered the HELB should be included as a source of flooding, but water sources from piping adjacent to the HELB pipe that may be subjected to damage from pipe whips do not need to be considered. The licensee’s assessment is focused on PINGP’s response to the Giambusso letter (XXXXX Accession No. ML102100067) concerning the potential for flooding safety-related equipment resulting from a HELB. In responding to paragraph 9.29.15 of the Giambusso letter, concerning flooding potential from HELBs, PINGP discussed flooding from the HELB-ruptured pipe itself in a specific system in the Auxiliary Building. In its March 17, 1973, response contained in Final Safety Analysis Report (FSAR) Amendment 31 (XXXXX Accession No. ML102100175), PINGP did not CONTACT: Xxxxx X. Xxxxxx, NRR/DPR 000-000-0000 provide a discussion or consideration of other sources of water from a secondary rupture due to pipe whip. In fact, there is no discussion of any adjacent or target pipe, or pipe whip in the flooding paragraph. The licensee subsequently concluded that the Atomic Energy Commission (AEC) approved the PINGP response through the staff’s safety evaluation report (SER) and, therefore, accepted the premise that consequential flooding from the secondary pipe rupture is not required to be analyzed.
Licensee Position. The licensee’s position is that water sources from the pipe that suffered the HELB should be included as a source of flooding; however, water sources from piping adjacent to the HELB pipe that may be subjected to damage from pipe whips do not need to be considered. The licensee’s assessment is focused on PINGP’s response to the Giambusso letter concerning the potential for flooding safety-related equipment resulting from the HELB. In answering paragraph 9.29.15 of the Giambusso letter, concerning flooding potential from HELBs, PINGP discussed flooding from the HELB-ruptured pipe itself in a specific system in the Auxiliary Building. In its response, PINGP did not provide a discussion or consideration of other sources of water from a secondary rupture due to pipe whip. In fact, there is no discussion of any adjacent or target pipe, or pipe whip in the flooding paragraph. The licensee subsequently concluded that AEC approved the PINGP response through the staff’s safety evaluation report (SER); and therefore, accepted the premise that consequential flooding from the secondary pipe rupture is not required to be analyzed. Based on the thought process above, the licensee does not consider the fire projection sprinklers a water source since there was no specific discussion in the Giambusso discussion. Regulatory Evaluation The USAR established the licensing basis in Sections 6 and 12 for flooding (Section 12- “The Class I items are protected against damage from rupture of a pipe or tank resulting in serious flooding or excessive steam release to the extent that Class I function is impaired.”) Section 6 notes that internal flooding, which could be postulated to adversely affect the performance of Engineered Safety Features, was a part of the original plant design criteria. It further suggests that the turbine building was a building for which protection is designed to mitigate the consequences of flooding. The PINGP licensing basis for HELB impacts on adjacent piping resides in Section 12 (“Class I items are protected against damage from: Pipe whip and steam/water jets following a pipe rupture of an adjacent pipe”). The type of damage is discussed in USAR Appendix I. If the pipe is not restrained and is capable of striking a smaller diameter pipe with a smaller wall thickness than the target or adjacent pipe, one should conclude that the target or adjacent pipe is ruptured (unless an analysis shows this not to be the case). Since the pipe ruptures, water will flo...
