L-14-166, Revise Technical Specification 4.3.2, Spent Fuel Storage Pool Minimum Inadvertent Drainage Elevation

Revise Technical Specification 4.3.2, Spent Fuel Storage Pool Minimum Inadvertent Drainage Elevation

ML14153A388
Person / Time
Site:	Beaver Valley
Issue date:	06/02/2014
From:	Emily Larson FirstEnergy Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-14-166
Download: ML14153A388 (15)

Text

FENOCTM Beaver Valley Power Station P.O. Box 4 Shippingport, PA 15077 FirstEnergy Nuclear Operating Company Eric A. Larson 724-682-5234 Site Vice President Fax: 724-643-8069 June 2, 2014 L-14-166 10 CFR 50.90 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

SUBJECT:

Beaver Valley Power Station, Unit No. 2 BV-2 Docket No. 50-412, License No. NPF-73 Revise Technical Specification 4.3.2, Spent Fuel Storage Pool Minimum Inadvertent Drainage Elevation Pursuant to 10 CFR 50.90, FirstEnergy Nuclear Operating Company (FENOC) hereby requests an amendment to the operating license for Beaver Valley Power Station, Unit No. 2 (BVPS-2). The proposed amendment is required to correct the minimum drain elevation for the spent fuel storage pool specified in Technical Specification 4.3.2.

In accordance with 10 CFR 50, Appendix B, Section XVI, "Corrective Action," and the FENOC Corrective Action Program, this proposed amendment is required to resolve a Technical Specification discrepancy regarding an existing plant design feature and is not a voluntary request from a licensee to change its licensing basis. The FENOC evaluation of the proposed amendment is enclosed.

FENOC requests approval of the proposed amendment by June of 2015. There are no regulatory commitments contained in this letter. If there are any questions or if additional information is required, please contact Mr. Thomas A. Lentz, Manager-Fleet Licensing, at 330-315-6810.

I declare under penalty of perjury that the foregoing is true and correct. Executed on June _2_, 2014.

Sincerely, Eric A. Larson

Beaver Valley Power Station, Unit No. 2 L-14-166 Page2

Enclosure:

FENOC Evaluation of Proposed Amendment cc: NRC Region I Administrator NRC Resident Inspector NRC Project Manage r Director BRP/DEP Site BRP/DEP Representative

Evaluation of the Proposed Amendment Page 1 of 9

Subject:

License Amendment Application to Revise Technical Specification 4.3.2, Spent Fuel Storage Pool Minimum Inadvertent Drainage Elevation.

1.0

SUMMARY

DESCRIPTION 2.0 DETAILED DESCRIPTION

4.0 REGULATORY EVALUATION

4.1 Significant Hazards Consideration 4.2 Applicable Regulatory Requirements/Criteria 4.3 Conclusion

5.0 ENVIRONMENTAL CONSIDERATION

Attachments:

1. Proposed Technical Specification Change (Mark-Up)

2. Retyped Technical Specification Page

Evaluation of the Proposed Amendment Beaver Valley Power Station, Unit No. 2 Page 2 of 9 1.0

SUMMARY

DESCRIPTION This evaluation supports a request to change a Technical Specification contained in Appendix A to Operating License NPF-73 for Beaver Valley Power Station, Unit No.2 (BVPS-2).

Design Feature 4.3.2, "Drainage," requires that the spent fuel storage pool be designed to prevent inadvertent draining of the pool below a certain specified elevation. The proposed change would revise this specified elevation to reflect the installed piping by lowering the elevation 5 inches.

2.0 DETAILED DESCRIPTION During a review of operating experience FirstEnergy Nuclear Operating Company identified a discrepancy. Based on plant drawings, the spent fuel storage pool cooling pump suction piping passes through the spent fuel storage pool liner wall at a pipe centerline elevation of 751 feet, 3 inches. The nominal inner diameter of the pipe is 10 inches; therefore, the lowest elevation of the inside diameter of this pipe where it enters the spent fuel storage pool is 750 feet, 10 inches. Elevation 750 feet, 10 inches is lower than the minimum inadvertent drainage elevation currently specified for the spent fuel storage pool in Technical Specification 4.3.2. Therefore, FirstEnergy Nuclear Operating Company issued a condition report to document and address this discrepancy.

Design document reviews identified fuel pool purification pump suction piping that penetrates the spent fuel storage pool wall in the cask area and fuel storage area of the pool and extends vertically down to a minimum elevation of 750 feet, 10 inches.

Figure 1 shows design feature elevations in a simplified drawing of the spent fuel storage pool. The elevations and dimensions discussed in this evaluation and shown in the figure are nominal values.

Technical Specification Section 4.0, "Design Features," Subsection 4.3, "Fuel Storage,"

Specification 4.3.2, "Drainage," states that for Beaver Valley Power Station, Unit No. 2:

The spent fuel storage pool is designed and shall be maintained to prevent inadvertent draining of the pool below elevation 751 feet- 3 inches.

The proposed Technical Specification change would revise the specified elevation to read 750 feet- 10 inches. Attachment 1 provides Technical Specification page 4.0-4 marked to show the proposed change. Attachment 2 provides retyped Technical Specification page 4.0-4 incorporating the proposed change.

Beaver Valley Power Station, Unit No. 2 Updated Final Safety Analysis Report (UFSAR)

Table 1.8-1, "USNRC Regulatory Guides," states that the design of the spent fuel storage facilities follow the guidance of USNRC Regulatory Guide 1.13, "Spent Fuel Storage Facility Design Basis," Revision 1, (Accession No. ML003739943), with certain alternatives. BVPS-2 UFSAR Section 9.1.2.3, "Safety Evaluation," states in part that:

Evaluation of the Proposed Amendment Beaver Valley Power Station, Unit No. 2 Page 3 of 9 In accordance with Regulatory Guide 1.13, the storage and handling of fuel in the fuel building is designed to protect the fuel, limit potential offsite exposures, and prevent loss of water from the [spent] fuel [storage] pool which may uncover the fuel.

The spent fuel [storage] pool is designed such that the water level in the pool cannot be decreased below the top of the fuel stored in the spent fuel racks. The fuel transfer gates do not extend below the top of the spent fuel assemblies, and all piping and piping penetrations of the spent fuel [storage] pool terminate no lower than 10 feet above the top of the fuel stored in the racks.

This UFSAR reference to "the fuel stored in the racks" refers to the top of the active fuel stored in the racks, since the current Technical Specification value of 751 feet, 3 inches is more than 10 feet above the top of the fuel pellets stored in the racks but less than 10 feet above the top of the fuel assemblies.

Section 9.1.3.3, "Safety Evaluation," of the BVPS-2 UFSAR, states in part that:

Water level in the spent fuel [storage] pool cannot be lowered below 10 feet above the top of the fuel stored in the spent fuel racks due to the design of the pool, as described in Section 9.1.2, and by the design of the piping, which does not allow any piping termination below this elevation.

While investigating whether a minimum of 10 feet of water coverage is provided above the top of the fuel stored in the spent fuel storage pool racks, it was discovered that certain racks are higher than expected due to shimming, and the active nuclear fuel pellet stack in the spent fuel assemblies can grow due to irradiation. The rack shims and the fuel pellet growth can reduce the minimum water coverage over the fuel in the spent fuel storage pool by approximately 0.7 inches and 1.24 inches, respectively.

FirstEnergy Nuclear Operating Company issued condition reports to document and address these items.

The minimum water level over the active fuel when drained to the proposed Technical Specification minimum inadvertent drain level of 750 feet - 10 inches, considering the reductions due to rack shims and fuel pellet growth is approximately 9.89 feet.

3.0 TECHNICAL EVALUATION

General Design Criterion 61, "Fuel storage and handling and radioactivity control," set forth in Appendix A, "General Design Criteria for Nuclear Power Plants," of 10 CFR 50, requires that fuel storage and handling, radioactive waste, and other systems that may contain radioactivity be designed to assure adequate safety under normal and postulated accident conditions. The five design provisions listed in General Design Criterion 61 for these systems are presented below. The text that follows each design provision indicates if the design provision relates directly to the proposed Technical Specification change, and if it does not relate, it describes why it does not relate.

Evaluation of the Proposed Amendment Beaver Valley Power Station, Unit No. 2 Page 4 of 9 These systems shall be designed:

(1) with a capability to permit appropriate periodic inspection and testing of components important to safety, This design provision does not directly relate to the proposed Technical Specification change. The proposed change involves the fuel storage system at BVPS-2 and does not affect fuel handling, radioactive waste, or other systems that may contain radioactivity. Capability to permit periodic inspection and testing of fuel storage system components (that is, pumps and valves of the spent fuel storage pool cooling and cleanup system) is not affected by the proposed Technical Specification change.

(2) with suitable shielding for radiation protection, This design provision directly relates to the proposed Technical Specification change. A discussion of the effects of the proposed Technical Specification change on radiation shielding is provided later in this Technical Evaluation.

(3) with appropriate containment, confinement, and filtering systems, This design provision does not directly relate to the proposed Technical Specification change. The proposed change to the spent fuel storage pool minimum inadvertent drainage elevation does not involve any changes to the containment structure, containment isolation arrangements, the fuel building structure, or the fuel building ventilation system and therefore does not affect the capability to limit the potential release of radioactive iodine and other radioactive materials.

The spent fuel storage pool water level is credited for iodine absorption in the event of a fuel handling accident. However, inadvertent draining of the spent fuel storage pool to the minimum inadvertent drainage elevation is not postulated to occur coincident with a fuel handling accident. Twenty-three feet of water in the spent fuel storage pool is assumed for the fuel handling accident.

(4) with a residual heat removal capability having reliability and testability that reflects the importance to safety of decay heat and other residual heat removal, and This design provision does not directly relate to the proposed Technical Specification change. Reducing the spent fuel storage pool minimum inadvertent drainage elevation by five inches does not affect the reliability or testability of spent fuel storage pool residual heat removal capability (that is, the spent fuel storage pool cooling system). However, if the spent fuel storage pool water level was allowed to drop to the proposed minimum inadvertent drainage elevation, the spent fuel pool cooling system will no longer be capable of residual heat removal.

Evaluation of the Proposed Amendment Beaver Valley Power Station, Unit No. 2 Page 5 of 9 (5) to prevent significant reduction in fuel storage coolant inventory under accident conditions.

This design provision does not directly relate to the proposed Technical Specification change. Accidents related to the spent fuel storage pool are discussed in UFSAR Sections 15.7.4, "Radiological Consequence of Fuel Handling Accidents," and 15.7.5, "Spent Fuel Cask Drop Accidents." Evaluations of these accidents are not affected by the proposed Technical Specification change, because maloperation or passive piping failure causing inadvertent draining of the spent fuel storage pool is not postulated concurrent with the fuel handling or spent fuel cask drop accidents.

The spent fuel storage area is designed in accordance with General Design Criterion 2 as it relates to the facility being capable of withstanding the effects of natural phenomena, such as earthquakes, tornadoes, hurricanes, and floods. The proposed Technical Specification change does not affect the design features of the fuel storage area or fuel building that are provided to withstand the effects of natural phenomenon and therefore, does not affect the capability to withstand the effects of natural phenomenon. Therefore, the proposed Technical Specification change does not affect design provisions that prevent significant reduction in fuel storage coolant inventory under accident conditions.

Suitable shielding for radiation protection is the only provision of General Design Criterion 61 that relates directly to the proposed Technical Specification change.

If the spent fuel storage pool water level was inadvertently reduced through maloperation or piping failure, the water level could drain to the 750 feet, 10 inch elevation. Although the Technical Specification stated minimum inadvertent drainage elevation needs to be revised to reflect the spent fuel storage pool design, the reduced minimum elevation of piping and penetrations continues to ensure approximately 3 meters (9.84 feet) of water will remain above the top of the active fuel stored in the spent fuel storage pool racks. Three meters of water coverage was selected for evaluation because it bounds the minimum water level of approximately 9.89 feet over the top of the active fuel that is present when the spent fuel storage pool is drained to 750 feet- 10 inches.

The conservatively high calculated gamma radiation dose rate for personnel located at the fuel building operating floor elevation, directly above freshly discharged fuel assemblies stored in the spent fuel storage pool with the pool water level reduced to the 750 feet, 10 inch elevation (providing at least 9.84 feet of water above the active fuel) is estimated to be approximately 280 millirem per hour. This calculation result can be used to estimate operator exposure for post drain-down event mitigation activities. The calculated dose rate is comparable to dose rates for certain outage maintenance activities (fall 2012 outage maximum under head inspection dose rate at 185 millirem per hour and maximum steam generator channel head work dose rate at 853 millirem per hour) and permits corrective maintenance to be performed within occupational dose

Evaluation of the Proposed Amendment Beaver Valley Power Station, Unit No. 2 Page 6 of 9 limits of 10 CFR 20.1201. Therefore, it is concluded that the spent fuel storage pool water elevation of 750 feet, 10 inches provides suitable shielding for radiation protection as required by General Design Criterion 61.

Reducing the spent fuel storage pool minimum shielding depth from the UFSAR specified 10 feet above the top of the fuel stored in the racks to 9.84 feet above the top of the active fuel stored in the racks corresponds to an approximate 51 millirem per hour increase in the radiation dose rate for personnel located at the fuel building operating floor elevation. As stated above, the calculated dose rate (with this increase) is comparable to dose rates for certain outage maintenance activities and permits corrective maintenance to be performed within occupational dose limits.

In summary, this Technical Specification change is being proposed to reflect the actual plant design and the resulting reduction in the available spent fuel storage pool minimum inadvertent drainage elevation. This reduced minimum water level continues to ensure that in the event of maloperation or failure of the piping, the loss of coolant will not uncover fuel and the remaining water in the spent fuel storage pool will provide adequate shielding for radiation protection. The proposed Technical Specification change is less restrictive but affords adequate assurance of safety. No design basis accidents are affected by the proposed Technical Specification change.

4.0 REGULATORY EVALUATION

FirstEnergy Nuclear Operating Company proposes to amend Section 4.3, "Fuel Storage," Specification 4.3.2, "Drainage," in the design features section of the Beaver Valley Power Station, Unit No. 2, Technical Specifications. Specification 4.3.2 identifies the elevation below which the spent fuel storage pool is designed to prevent inadvertent draining. The proposed amendment would reduce this minimum specified elevation by 5 inches based on plant design drawings.

4.1 Significant Hazards Consideration FirstEnergy Nuclear Operating Company has evaluated whether or not a significant hazards consideration is involved with the proposed license amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:

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

Response: No.

Previously evaluated accidents including a fuel handling accident and spent fuel cask drop accident are not affected by the proposed amendment.

Reducing the minimum water level above fuel stored in the spent fuel storage pool in the event of inadvertent draining as proposed would not involve a significant increase in the probability of a previously evaluated

Evaluation of the Proposed Amendment Beaver Valley Power Station, Unit No. 2 Page 7 of 9 accident. Maloperation or passive piping failure causing inadvertent draining of the spent fuel storage pool is not postulated concurrent with the fuel handling or spent fuel cask drop accident. The proposed amendment would not result in any failure modes that could initiate an analyzed accident, and does not increase the likelihood of a malfunction of a system, structure or component; therefore, the probability of analyzed accidents is not affected.

There are no changes to how the station will be operated, limiting conditions for operation, or limiting safety system settings. The proposed amendment does not affect the capability of a system, structure or component to perform a design function. Since design functions are not affected by the proposed amendment, the consequences of previously evaluated accidents are not affected.

Therefore, the proposed amendment 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.

Reducing the minimum water level above fuel stored in the spent fuel storage pool in the event of inadvertent draining as proposed does not create any new failure mechanisms, malfunctions, or accident initiators and does not change design functions or system operation in a way that affects the ability of systems, structures, and components to perform design functions.

Therefore, the proposed 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.

General Design Criterion 61, "Fuel storage and handling and radioactivity control," of 10 CFR 50, Appendix A, states in part that fuel storage and handling systems shall be designed with suitable shielding for radiation protection.

The proposed change involves a reduction in the minimum elevation of piping and penetrations of the spent fuel storage pool specified in the

Evaluation of the Proposed Amendment Beaver Valley Power Station, Unit No. 2 Page 8 of 9 Technical Specifications. In the event maloperation or passive piping failure causes inadvertent draining of the spent fuel storage pool, the remaining water level in the pool ensures the stored fuel remains covered, provides adequate shielding for personnel, and affords adequate assurance of safety when judged against the current regulatory standard of General Design Criterion 61.

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

Based on the above, FirstEnergy Nuclear Operating Company concludes that the proposed amendment does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration" is justified.

4.2 Applicable Regulatory Requirements/Criteria The proposed amendment will continue to ensure compliance with General Design Criterion 61. The proposed amendment permits a reduction in the minimum water level above fuel stored in the spent fuel storage pool in the event of inadvertent draining of the pool due to maloperation or a pipe break but still affords adequate assurance of safety by continuing to provide suitable shielding for radiation protection as required by General Design Criterion 61.

4.3 Conclusion In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

5.0 ENVIRONMENTAL CONSIDERATION

The proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.

Evaluation of the Proposed Amendment Beaver Valley Power Station, Unit No. 2 Page 9 of 9

,,,, Top View l) c::

Pool Area Cask Area tt I I I Transfer Canal

~~

Side View

~

2 o__g) Q)

I--

-......~

I I I I I I I I I I I I I i I i I I I I I I i I I I I I I I I I I I I Spent Fuel I I I I I I I I I I I I I I I I I I I I I I I I I I I I I No t to Scale I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I

<D Elevation of internal bottom of spent fuel storage pool cooling pumps suction pipe where it penetrates the wall of the fuel pool is 750 feet, 10 inches (750.83 feet).

<V Elevation at the bottom of the fuel pool purification pumps suction pipes in the pool and cask areas is 750 feet, 10 inches.

Elevation at the bottom of the gate opening between the 750.83 feet pool area and cask area is 742 feet, 1 inch (742.08 feet). -740.94 feet 9.89 feet Elevation at the top of the fuel assemblies (not including the top nozzle springs) is 741.82 feet.

~ Elevation at the top of the active fuel is 740.94 feet or lower.

Figure 1, Spent Fuel Storage Pool

Attachment 1 Proposed Technical Specification Change (Mark-Up)

(1 page follows)

Design Features 4.0 4.0 DESIGN FEATURES 4.3 Fuel Storage (continued) 4.3.2 Drainage Unit 1 The spent fuel storage pool is designed and shall be maintained to prevent inadvertent draining of the pool below elevation 750 feet - 10 inches.

Unit 2 The spent fuel storage pool is designed and shall be maintained to prevent inadvertent draining of the pool below elevation 751 feet 3 inches.

4.3.3 capacity [750-f~-~t-:1-oi~~h~;Y Unit 1 L--------------------'

The spent fuel storage pool is designed and shall be maintained with a storage capacity limited to no more than 1627 fuel assemblies.

Unit 2 The fuel storage pool is designed and shall be maintained with a storage capacity limited to no more than 1088 fuel assemblies (Boraflex racks), 1690 fuel assemblies (Metamic racks).

Beaver Valley Units 1 and 2 4.0-4 Amendments 278 I 173

Attachment 2 Retyped Technical Specification Page (1 page follows)

Design Features 4.0 4.0 DESIGN FEATURES 4.3 Fuel Storage (continued) 4.3.2 Drainage Unit 1 The spent fuel storage pool is designed and shall be maintained to prevent inadvertent draining of the pool below elevation 750 feet - 10 inches.

Unit 2 The spent fuel storage pool is designed and shall be maintained to prevent inadvertent draining of the pool below elevation 750 feet- 10 inches.

4.3.3 Capacity Unit 1 The spent fuel storage pool is designed and shall be maintained with a storage capacity limited to no more than 1627 fuel assemblies.

Unit 2 The fuel storage pool is designed and shall be maintained with a storage capacity limited to no more than 1088 fuel assemblies (Boraflex racks), 1690 fuel assemblies (Metamic racks).

Beaver Valley Units 1 and 2 4.0-4 Amendments 278 I TBD