ML13203A005

Exigent Local Proposed Notice of Consideration of Issuance of Amendment, Revise Current Licensing Basis to Adopt Revised Design Basis/Methodology for Addressing Design-Basis Tornado/Tornado Missile Impact

ML13203A005
Person / Time
Site:	Fort Calhoun
Issue date:	07/23/2013
From:	Joseph Sebrosky Plant Licensing Branch IV
To:	Cortopassi L Omaha Public Power District
Sebrosky J
References
TAC MF2469
Download: ML13203A005 (7)

Text

PUBLIC NOTICE NRC STAFF PROPOSES TO AMEND RENEWED FACILITY OPERATING LICENSE AT THE FORT CALHOUN STATION, UNIT 1 The U.S. Nuclear Regulatory Commission (NRC) staff has received an application dated July 21, 2013, from Omaha Public Power District (OPPD, the licensee), for an exigent amendment to the renewed operating license for the Fort Calhoun Station, Unit 1, located in Washington County, Nebraska.

The proposed amendment would revise the Updated Safety Analysis Report (USAR) for the design-basis tornado (DBT) and tornado missiles to include Regulatory Guide (RG) 1.76, Revision 1, Design-Basis Tornado and Tornado Missiles for Nuclear Power Plants, and Bechtel Power Corporation, Topical Report BC-TOP-9A, Revision 2, September 1974, Design of Structures for Missile Impact. As described in the license amendment application, the changes will revise the current licensing basis (CLB) pertaining to protection from tornadoes and tornado-generated missiles. Section C of RG 1.76, Revision 1 established the regulatory position for licensees to use in selecting the DBT and DBT-generated missiles that a nuclear power plant should be designed to withstand to prevent undue risk to public health and safety.

BC-TOP-9A, Revision 2 provides a methodology approved by the Atomic Energy Commission (AEC) for evaluating the impact of tornado missiles. With these changes, the licensee ensures that the plant can reach safe shutdown and be maintained in a safe shutdown condition during a tornado in accordance with Appendix G, Criterion 2, of the USAR.

In its July 21, 2013 license amendment application, OPPD described installing physical protection against tornadoes for certain equipment. During equipment installation, and associated reviews of the existing licensing basis and discussions with the NRC staff, OPPD determined that it needed to request the amendment described above. OPPD explained that it did not submit the amendment sooner because it had not previously concluded that prior NRC

approval was required. OPPD noted that these changes must be obtained to support plant startup and that due to the complex and integrated nature of the activities required to recover from an extended outage, an extended delay in a key activity would have a cascading, adverse impact on the resumption of operations. Therefore, OPPD requested that the license amendment request be processed under exigent circumstances in accordance with paragraph 50.91(a)(6) of Title 10 of the Code of Federal Regulations (10 CFR). An "exigent" amendment reduces the time the public and State have to comment on the associated issue of "no significant hazards consideration" and allows for notice to be provided through local media (e.g.,

a newspaper) instead of through the Federal Register. 10 CFR 50.91(a)(6)(i)(B).

The Commission's regulation at 10 CFR 50.91(a)(1) requires that, at the time a licensee requests an amendment, the licensee must provide to the Commission the licensee's analysis about the issue of no significant hazards consideration using the standards in § 50.92, which concern whether the proposed amendment (1) involves a significant increase in the probability or consequences of an accident previously evaluated; or (2) creates the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involves a significant reduction in a margin of safety.

Accordingly, the licensee provided the following information:

1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No.

The proposed change to the current licensing basis (CLB) utilizes current NRC guidance (i.e., Regulatory Guide (RG) 1.76, Revision 1),

regarding the characteristics of the design basis tornado (DBT) and associated missiles and NRC-approved methodology (i.e., Bechtel Topical Report BC-TOP-9A, Revision 2) for the analysis thereof. These NRC-approved documents will form the basis for ensuring that recently identified tornado missile targets are adequately protected.

The proposed change does not increase the probability or consequences of an accident previously evaluated. The proposed change is more comprehensive than the CLB as it will require consideration of the vertical velocity component of DBT missiles, and use an approved methodology BC-TOP-9A for analyzing tornado missile impact. This will provide a basis for analyzing and protecting designated SSCs [structures, systems, and components] using protective barriers to enable the plant to reach safe shutdown and be maintained in a safe shutdown condition during a tornado.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No.

The proposed amendment provides the regulatory basis for changing the CLB to require compliance with RG 1.76, Revision 1 for the DBT and associated missiles, and use an approved methodology BC-TOP-9A for analyzing tornado missile impact. The proposed amendment does not involve a change in methods governing plant operation. The proposed amendment requires consideration of the vertical velocity component of DBT missiles not presently required by the CLB. Designated SSCs are protected by barriers against the RG 1.76, Revision 1 DBT and associated missiles to ensure the plant can reach safe shutdown and be maintained in a safe shutdown condition during a tornado.

No new interactions between systems or components are created.

No new failure mechanisms of associated systems will exist. The proposed amendment ensures that designated SSCs are protected from the effects of the DBT and associated missiles in accordance with current NRC guidance.

Therefore, the amendment does not create the possibility of a new or different kind of accident from any previously evaluated.

3. Does the proposed amendment involve a significant reduction in a margin of safety?

Response: No.

The proposed amendment provides the regulatory basis for changing the CLB to utilize updated NRC guidance regarding the characteristics of the DBT and associated missiles. Designated SSCs are protected in accordance with the most recent NRC guidance and approved methodologies as documented above regarding the characteristics of the DBT and DBT missiles and how to analyze their impact on structures, systems and components. The proposed amendment does not alter the manner in which safety limits or limiting safety system settings are determined. The safety analysis acceptance criteria are not affected by the proposed amendment.

Further, the proposed amendment does not change the design function of any equipment assumed to operate in the event of an accident. The proposed change provides a basis for protecting designated SSCs in accordance with current NRC guidance and approved methodologies to enable the plant to reach safe shutdown and be maintained in a safe shutdown condition during a tornado.

Therefore, the proposed amendment does not involve a significant reduction in a margin of safety.

Following the NRC Staffs initial review of this license amendment application, the requested amendment has been evaluated against the standards in § 50.92 and the NRC Staff has made a proposed (preliminary) determination that the requested amendment involves no significant hazards considerations. The changes do not significantly increase the probability or consequences of any accident previously considered, nor create the possibility of an accident of

a different kind, nor significantly decrease any margin of safety. The staff notes that the analyzed accidents can be found in Chapter 14 of the Fort Calhoun Station USAR.

If the proposed determination that the requested license amendment involves no significant hazards consideration becomes final, the staff will issue the amendment without first offering an opportunity for a public hearing. An opportunity for a hearing will be published in the Federal Register at a later date and any hearing request will not delay the effective date of the amendment.

If the staff decides in its final determination that the amendment does involve a significant hazards consideration, a notice of opportunity for a prior hearing will be published in the Federal Register and, if a hearing is granted, it will be held before the amendment is issued.

Comments on the proposed determination of no significant hazards consideration may be (1) telephoned to Joseph M. Sebrosky, Senior Project Manager, Plant Licensing Branch IV, by collect call to 301-415-1132, or by facsimile to 301-415-1885, (2) e-mailed to joseph.sebrosky@nrc.gov (3) submitted in writing to the Chief, Rules, Announcements and Directives Branch, Division of Administrative Services, Office of Administration, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001. All comments received by close of business on July 25, 2013, from 7:30 a.m. to 4:15 p.m. Federal workdays will be considered in reaching a final determination. A copy of the application dated July 21, 2013, may be examined electronically through the NRCs Agencywide Documents Access and Management System (ADAMS) at Accession No. ML13203A136 in the NRC Library at http://www.nrc.gov/reading-rm/adams.html and at the Commission's Public Document Room (PDR), located at One White Flint North, Public File Area O1 F21, 11555 Rockville Pike (first floor), Rockville, Maryland.

Persons who do not have access to ADAMS or who encounter problems in accessing the

documents located in ADAMS should contact the NRC PDR Reference staff by telephone at 1-800-397-4209, or 301-415-4737, or by e-mail to pdr.resource@nrc.gov.