Correction to Comments on the Final Rule “List of Approved Spent Fuel Storage Casks: (HI-STAR 100) Addition”

AGENCY:

Nuclear Regulatory Commission.

ACTION:

Final rule; correction.

SUMMARY:

The Nuclear Regulatory Commission (NRC) is supplementing the administrative record of the final rule “List of Approved Spent Fuel Storage Casks: (HI-STAR 100) Addition” (64 FR 48259; September 3, 1999) to ensure a complete and accurate administrative record. This document corrects several comment responses that were inconsistent with the corresponding language contained in the NRC staff's Safety Evaluation Report (SER) or the Certificate of Compliance (CoC), or that needed additional clarification; corrects two pages in the CoC due to typographical errors; and corrects the CoC expiration date listed in the rule text.

EFFECTIVE DATE:

This correction is effective October 4, 1999.

FOR FURTHER INFORMATION CONTACT:

Stan Turel, telephone (301) 415-6234, e-mail spt@nrc.gov of the Office of Nuclear Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001.

SUPPLEMENTARY INFORMATION:

Discussion

The NRC issued a final rule amending 10 CFR 72.214 on September 3, 1999; (see 64 FR 48259), which approved the Holtec HI-STAR 100 spent fuel storage cask design. Subsequently, Holtec notified the NRC by letters dated September 28 and September 29, 1999, that several of the responses to public comments contained in the final rule required additional clarification. The NRC staff has reviewed Holtec's letters and agrees that some of the responses were not complete. Therefore, the staff is revising the responses to several public comments contained in the final rule. The changes are made to ensure a complete and accurate administrative record. Holtec also notified the NRC, in these letters, that the final CoC contained two typographical errors. Corrected CoC pages have been issued to Holtec and placed in the NRC Public Document Room. Additionally, the NRC staff identified that the CoC expiration date in § 72.214 of the final rule was incorrect (see 64 FR 48274). The Office of Federal Register subsequently published a correction notice in the Federal Register (64 FR 50872; September 20, 1999); however, the CoC expiration date in that notice was also in error. Therefore, this notice corrects the CoC expiration date in the rule text of § 72.214 to read as “October 4, 2019.”

I. Correction of Response to Comments

Revised responses to Comment Nos. 23, 27, 30, 36, 54, and 70 are as follows:

Comment No. 23: One commenter asked how the pre-passivation or anodization of aluminum surfaces is checked? The commenter believes this activity should be checked and asked if there is criteria for this inspection.

Revised Response: A separate check or inspection of the pre-passivation of aluminum surfaces is not necessary. Aluminum is used in the MPC-24, MPC-68, and MPC-68F baskets for the Boral neutron absorbers and aluminum heat conduction elements that enhance heat transfer from the fuel basket to the MPC shell. When exposed to air or water, aluminum immediately forms a very thin, compact, and adherent film of aluminum oxide, which becomes thicker with increasing temperatures in the presence of water. Holtec's fabrication procedures specify that both the Boral neutron absorbers and the heat conduction elements are immersed in water for a minimum of 72 hours before these components are installed in the MPC. During this fabrication step, the absence of any gas bubbles emanating from the water after 72 hours indicates that all exposed aluminum surfaces have been covered with aluminum oxide (i.e., the aluminum surfaces have been passivated). These fabrication activities are accomplished under Holtec's approved Quality Assurance program. Therefore, a physical inspection of these aluminum components is not necessary to ensure that the surfaces have been properly passivated.

Comment No. 27: One commenter asked whether the design has been evaluated for a seismic event during loading and unloading.

Revised Response: The HI-STAR cask is designed to withstand seismic motions while in storage on the ISFSI pad without tipping over or sliding. The seismic accelerations used in the generic design basis for the HI-STAR 100 system are documented in the HI-STAR 100 CoC and TSAR. There are no cask seismic supports or restraints required during loading or unloading operations by the generic cask operating procedures in the TSAR. Seismic considerations are among the design bases that individual users must evaluate if using the HI-STAR 100 pursuant to the general licensing requirements of 10 CFR part 72. Each utility choosing to use the general license must perform an evaluation pursuant to 10 CFR 72.212 to determine whether its site-specific seismic accelerations at the locations where loading and unloading operations take place are bounded by the generic values in the CoC and TSAR. Based on this evaluation, users must determine whether any seismic support for the cask is required.

Comment No. 30: One commenter questioned the drain-down time and asked how frequently the water is checked. The commenter requested information on what happens if the MPC can't be vacuum dried successfully, and when the fuel needs to be put back in the pool.

Revised Response: The HI-STAR 100 cask design does not require any limitations on drain-down time (i.e., how long it takes to drain water from the MPC during the vacuum drying process). Holtec's thermal analysis of the spent fuel's peak cladding temperature during the vacuum-drying process demonstrated that, regardless of the length of time necessary to complete the drain-down and vacuum drying, the peak cladding temperature would remain less than the 570 °C (1058 °F) “short-term condition” temperature limit. Therefore, a drain-down time limit is not necessary and is not specified in the Technical Specifications (TS). Because there is no limitation on drain-down time, there is also no requirement on how frequently the water draining from the cask should be checked. Furthermore, because a drain-down time limit is not contained in the TS, a corresponding time limit for corrective actions is also not required (e.g., a requirement to unload a cask that cannot be successfully vacuum dried within a specified period of time). Limits on drain-down time and any corrective actions to be taken in response to exceeding these drain-down time limits may be voluntarily provided by the cask user as an operational aid in a site-specific vacuum-drying procedure. Separately, the NRC notes that the TS prohibit entry into the transport operation mode if LCO 2.1.1 is not met; and LCO 2.1.1 contains a vacuum drying pressure surveillance requirement.

Comment No. 36: One commenter asked whether shims are used and stated that shims or gaps were not acceptable.

Revised Response: The design and fabrication intent is that no shims be used in the closure weld of HI-STAR 100 casks. However, when the as-manufactured fit-up gap exceeds 1/16th inch between the lid and the shell, shims may be used, as shown on Design Drawing No. 1396, Sheet 1, for the MPC 24.

Comment No. 54: One commenter asked how lifting height should be verified and stated that the height should be recorded.

Revised Response: The maximum lifting height maintains the operating conditions of the Spent Fuel Storage Cask (SFSC) within the design and analysis basis. It is the general licensee's responsibility to limit the SFSC lifting height to allowable values. The lift height requirements are specified in TS LCO 2.1.3 for the vertical and horizontal orientations. Surveillance requirements require verification that SFSC lifting requirements are met after the SFSC is either suspended or secured in the transporter and prior to moving the SFSC within the ISFSI.

Comment No. 70: One commenter stated that the frequency of SR 2.1.3.1 should be revised because, as written, the frequency would apply only when a cask is being moved to or from the ISFSI and would not apply at other times, such as when moving casks within the ISFSI. However, the drop analysis applies any time the cask is suspended. The frequency should be revised similar to “Prior to movement of an SFSC.”

Revised Response: The NRC agrees with the comment. The frequency of SR 2.1.3.1 has been revised.

II. Corrections to CoC No. 72-1008

The NRC is correcting CoC No. 72-1008 to address two typographical errors that occurred during final printing. First, on page 10 in Appendix B, item 2.c is corrected to refer to Table 1.1-3 instead of Table 2.1-3. Second, the definition of the term FUEL DEBRIS in Appendix A (p. 1.1-1) is corrected to match the definition of the same term contained in Appendix B (page 1).

The NRC considers these CoC changes to be administrative corrections, which remove confusion and do not change the substance of the CoC. No other changes to CoC No. 72-1008 are being made. Revised CoC pages have been sent to Holtec and placed in the NRC Public Document Room.

III. Correction of Rule Text

In the final rule published in the Federal Register on September 3, 1999 (see 64 FR 48274) first column, under § 72.214, the expiration date for CoC No. 1008 was listed as “(20 years after the final rule effective date).” This was incorrect. Instead of text, the CoC expiration date should have been listed as a date certain. The final rule was effective on October 4, 1999; therefore, the CoC expiration date should have been listed as October 4, 2019. To address this problem the Office of Federal Register published a correction notice on September 20, 1999, (64 FR 50872) second column, under § 72.214, which specified a date certain of September 20, 2019. However, this date was also in error. This notice corrects the expiration date for CoC No. 1008 to read as “October 4, 2019.”

PART 72—LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL AND HIGH-LEVEL RADIOACTIVE WASTE

1. In § 72.214, Certificate of Compliance No. 1008, as published on September 3, 1999 on page 48274, first column, and corrected on September 20, 1999 on page 50872, second column, is further corrected to read as follows: