ML100750046

Attachment to E-Mail Transmitting Draft RAIs from Emcb Associated with AST License Amendment Request

ML100750046
Person / Time
Site:	Prairie Island
Issue date:	03/15/2010
From:	Beltz T Plant Licensing Branch III
To:	Hazelhoff A Enercon Services
beltz T, NRR/DORL/LPL3-1, 301-415-3049
Shared Package
ML100750045	List: ML100750041 ML100750046
References
TAC ME2609, TAC ME2610
Download: ML100750046 (2)

Text

ADAMS Accession No.: ML100750046 REQUESTS FOR ADDITIONAL INFORMATION Prairie Island Nuclear Generating Plant, Units 1 and 2 License Amendment Request (LAR) dated December 28, 2009 for Measurement Uncertainty Recapture Power Uprate Docket Nos. 50-282 and 50-306 TAC Nos. ME2609 and ME2610 Office of Nuclear Reactor Regulation Division of Engineering Mechanical & Civil Engineering Branch (EMCB)

EMCB RAI 1 Page 9 of the enclosure in Reference 1 indicates that credit will be taken for isolation dampers, which make up a portion of the Auxiliary Building Normal Ventilation System (ABNVS), as part of the proposed alternative source term (AST) implementation. Various justifications are provided for crediting these non-safety related dampers as part of the proposed implementation.

However, no justification is provided regarding the structural and seismic ruggedness of this equipment. Appendix A to 10 CFR Part 100 requires that structures, systems, and components (SSCs) necessary to assure the capability of the plant to mitigate the consequences of accidents, which could result in exposures comparable to the guideline exposures provided in 10 CFR Part 100, be designed to remain functional during and after a safe shutdown earthquake (SSE).

Please discuss the methodologies used to demonstrate the seismic ruggedness and/or seismic qualification of the aforementioned dampers. Additionally, please provide the references which provide the regulatory acceptance bases of these methodologies.

EMCB RAI 2 Section 3.0 of the enclosure in Reference 1 lists and describes the systems affected by the proposed AST implementation at PINGP. Aside from the dampers mentioned in EMCB RAI 1 and the systems outlined in Section 3.0, please indicate whether any additional mechanical equipment, components, or systems (i.e. air handling units (AHUs), motor control centers (MCCs), fans and I&C cabinets, etc.) will be credited as part of the implementation of the AST at PINGP. In accordance with the 10 CFR Part 100 requirements delineated above, for these items:

a) Indicate whether the equipment is new or existing.

b) Describe the location of the equipment and the seismic qualification method employed to demonstrate the seismic ruggedness of this equipment, such as the plant licensing basis or an NRC endorsed industry standard.

c) Summarize the results of the seismic qualification of the equipment, indicating whether any modifications or re-design will be necessary in support of the AST.

References

1) Letter from M. Schimmel, Northern States Power Company - Minnesota, to NRC Document Control Desk, Prairie Island Nuclear Generating Plant Units 1 and 2, Dockets 50-282 and 50-306, License Nos. DPR-42 and DPR-60, License Amendment Request (LAR) to Adopt the Alternative Source Term Methodology, dated October 27, 2009.

(ADAMS Accession No.: ML093160605)