Text

Response to Generic Letter 2016-01, Monitoring of Neutron-Absorbing Materials in Spent Fuel Pools.
	ML16305A323
Person / Time
Site:	Susquehanna
Issue date:	10/31/2016
From:	Franssen R; Susquehanna, Talen Energy
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	GL-16-001, PLA-7518
	Download: ML16305A323 (19)
	v • d • e

TALEN~

Robert J. Franssen Susquehanna Nuclear, LLC Plant Manager 769 Salem Boulevard Berwick, PA 18603 Tel. 570.542.3170 Fax 570.542.1504 ENERGY robert.franssen@talenenergy.com OCT 3 1 201 6 U.S. Nuclear Regulatory Commission 10 CFR 50.54(f)

ATTN: Document Control Desk Washington, DC 20555-0001 SUSQUEHANNA STEAM ELECTRIC STATION RESPONSE TO GENERIC LETTER 2016-01, "MONITORING OF NEUTRON-ABSORBING MATERIALS IN SPENT FUEL POOLS," Docket Nos. 50-387

~P=L=A~-7~5=1=8------------------------------------------ and50-388

References:

1. NRC Generic Letter 2016-01, "Monitoring ofNeutron-Absorbing Materials in Spent Fuel Pools,"

Apri/7, 2016.

2. NUREG-1931, "Safety Evaluation Report Related to the License Renewal of Susquehanna Steam Electric Station, Units 1 and 2, Docket Nos. 50.387 and 50.388, "November 2009 (ADAMs Accession No. ML093170780).

On April 7, 2016, the NRC issued Reference 1 to all power reactor licensees except those that have permanently ceased operation with all power reactor fuel removed from on-site spent fuel pool storage.

The purpose of this letter is to provide a response for Susquehanna Steam Electric Station (SSES) Unit 1 and Unit 2. Based upon review of Generic Letter 2016-01, SSES has determined that both Unit 1 and Unit 2 fall under Category 4 in accordance with Reference 1. As a Category 4 licensee, infmmation on the neutron absorber material, criticality analysis of record, and neutron absorber monitoring program is requested depending on the type of neutron absorber material present and credited in the spent fuel pool. The SSES Unit 1 and 2 spent fuel pools credit Boral and therefore are required to provide information in the following areas: 1, 2, and 4. Enclosure 1 contains responses to the requested information.

This letter contains no new regulatory commitments.

Should you have any questions regarding this submittal, please contact Mr. Jason Jennings, Manager- Nuclear Regulatory Affairs at (570) 542-3155.

Document Control Desk PLA-7518 I declare under penalty of perjury that the foregoing is true and correct.

Executed on: I 0 (3 f) do \ lo j

R. J. Franssen

Enclosure:

SSES Unit 1 and Unit 2 Response to Areas of Requested Information in Appendix A of Generic Letter 2016-01, "Monitoring ofNeutron-Absorbing Materials in Spent Fuel Pools" cc: Director, Office of Nuclear Reactor Regulation NRC Region I Mr. J. E. Greives, NRC Sr. Resident Inspector Ms. T. E. Hood, NRC Project Manager Mr. M. Shields, PA DEP/BRP

Enclosure 1 to PLA-7518 SSES Unit 1 and Unit 2 Response to Areas of Requested Information in Appendix A of Generic Letter 2016-01, "Monitoring of Neutron-Absorbing Materials in Spent Fuel Pools"

Enclosure to PLA-7 518 Page 1 of 16 Introduction On April 7, 2016, the Nuclear Regulatory Commission (NRC) issued Generic Letter 2016-01 (GL 2016-01), Monitoring ofNeutron-Absorbing Materials in Spent Fuel Pools (Reference 7).

The purpose of GL 2016-01 is to address degradation of neutron-absorbing materials in wet storage systems for reactor fuel at power and non-power reactors. The primary focus of the GL is neutron-absorbing material credited for limiting the maximum effective multiplication factor (keff) to less than that assumed in the licensing and design basis.

Specifically, the NRC has two purposes for issuing the GL:

1) To request submittal of information, or provide reference to previously docketed information, which demonstrates that credited neutron-absorbing materials in Spent Fuel Pools (SFP) are in compliance with the licensing, design basis and applicable regulatory requirements; and that there are measures in place to maintain this compliance.

2) To collect requested information and determine if additional regulatory action is required.

Susquehanna Steam Electric Station (SSES) Unit 1 and Unit 2 each have a Spent Fuel Pool with a common refuel floor. Each Spent Fuel Pool contains high density Boral racks containing neutron-absorbing material (B4C) in an aluminum matrix. The Spent Fuel Pools have the capability to be cross-connected for optimization of Spent Fuel Pool cooling and cleanup. The condition and capability of the Boral racks have been monitored by the station as part of the in-service inspection program established prior to startup. The in-service inspection program utilizes Boral test coupons which are located within the Spent Fuel Pool simulating the condition of the Spent Fuel racks over time (Reference 6).

In September 2006, Susquehanna Steam Electric Station (SSES) submitted a License Renewal Application (LRA) to the NRC for SSES Units 1 and 2 (Reference 1). Within the LRA, and corresponding Request for Additional Information (RAI) responses, SSES presented the NRC with the existing Spent Fuel Pool rack monitoring program. In response to NRC request, SSES included a License Renewal Commitment to continue to complete Boral coupon testing within the period of extended operation. This was reviewed and approved by the NRC under the License Renewal Safety Evaluation Report, NUREG-1931 (Reference 5).

Based upon review ofGL 2016-01, Susquehanna Steam Electric Station (SSES) has determined that both Unit 1 and Unit 2 fall under Category 4. SSES has an approved Spent Fuel Pool neutron-absorbing material monitoring program, as documented in Reference 5, but this program is not incorporated into the licensing basis.

As such, the SSES response to GL 2016-01 found in this enclosure consists of references to previously docketed information submitted under the SSES License Renewal Application (LRA). Additionally, SSES has reviewed the GL 2016-01 Appendix A, Guidance for Category 4 Responders to Generic Letter 2016-01, and provided responses to the requested information.

Any updates and missing information from that previously docketed has been provided within this response.

Enclosure to PLA-7 518 Page 2 of 16 Appendix A Request Reference SSES Response

1. Provide a description of the neutron-absorbing material credited in the Spent Fuel Pool (SFP) Nuclear Criticality Safety (NCS)

Analysis of Record (AOR) and its configuration in the SFP:

a) manufacturers, dates of manufacture, and dates of material Reference Rack Manufacturer: The SSES High Density Spent installation in the SFP; 16 Fuel Storage Racks (HDSFR) were purchased from PaR. The Boral was supplied to PaR by Brooks &

Perkins.

Manufacture Date: After a reasonable search of plant records, including docketed information, SSES determined that the requested information was not part of the original licensing basis or previously requested by the NRC as part of the licensing action that approved the neutron absorber monitoring program.

Installation Date: The SSES High Density Spent Reference Fuel Storage Racks (HDSFR) are the original racks 28 installed during plant construction. It is estimated that the racks were installed at Unit 1 in 1982 and at Unit 2 in 1983 . The Spent Fuel Racks were delivered to site during the 8/31/79 to 1/31/80 timeframe.

b) neutron-absorbing material specifications, such as: Reference The Spent Fuel Storage Rack Material Specifications

1. materials of construction, including the certified content 16 include the following:

of the neutron-absorbing component expressed as weight - The clad material is ASTM B209 Alloy 1100 percent;

- The aluminum core binder material meets the following chemical limits which exceed the requirements for 1100 alloy aluminum:

Fe 0.25% max Si 0.15% max Ti 0.20% max Other elements 0.03% max each Other elements 0.15% max total

Enclosure to PLA-7518 Page 3 of 16 Remainder 99.25% min aluminum

- (0.20% may be in the form of Aluminum Oxide)

- The boron carbide ASTM C750-74 Type 2 except that:

1) Total boron and carbon content allowed is 95% by weight min.

2) Total boron shall be 70.0 to 78.3 percent

3) B-10 isotopic content in boron shall be 19.75

+/- 1.0% by weight

11. minimum certified, minimum as-built, maximum as-built, Reference The areal density of the Boral in the SSES Spent and nominal as-built areal density of the neutron- 16 Fuel Storage Racks is equal to or greater than 0.0233 absorbing component; and grn/cm2 B-1 0 loading with 60 mesh size boron carbide.

Minimum B4C Content 0.192 (grams/ cm2)

Reference Minimum Attenuation Factor A@ .06 electron-volts 22 0.9630 (this equates to 0.0233 g/cm2 areal density).

Minimum as-built and Maximum as-built Areal Density: After a reasonable search of plant records, including docketed information, SSES determined that the requested information was not part of the original licensing basis or previously requested by the NRC as part of the licensing action that approved the neutron absorber monitoring program.

111. material characteristics, including porosity, density, and Reference The following describes the material characteristics dimensions; 16,22 of the Boral Panels within the Spent Fuel Storage Racks at SSES:

Size

Enclosure to PLA-7518 Page 4 of 16

1) Width 5 114" + 1/ 16"

- 1/32"

2) Length 152" +/- 5/32" Thickness 0.077" (Min) to 0.1 OO"(Max)

Squareness 5/ 16 inch total Lateral Bow - 3/16 inch max from 152 inch side edge Flatness General waviness of sheets shall not exceed 112 inch total Deviations shall not exceed 0.05 inch per linear inch.

Boral panel porosity is not available.

c) qualification testing approach for compatibility with the SFP Reference The qualification testing approach and results for environment and results from the testing 21 Bora} can be found in AAR Manufacturing Report 624.

d) configuration in the SFP, such as: Reference The neutron absorber material (Boral) is sealed

i. method of integrating neutron-absorbing material into 15, 16, 6, 1 within two concentric square aluminum tubes racks (e.g., inserts, welded in place, spot welded in place, referred to as poison cans. This information was rodlets); and previously provided under Reference 1.

11. sheathing and degree of physical exposure of neutron- Reference The neutron absorber material (Boral) is sealed absorbing materials to the SFP environment; 15, 16, 6, 1 within two concentric square aluminum tubes, as stated above. The neutron absorbing material is not exposed to the Spent Fuel Pool environment.

e) current condition of the credited neutron-absorbing material in the Reference SSES completed the latest Spent Fuel Pool coupon SFP, such as: 17,3 analysis in September 2015 from the Unit 1 Spent

i. estimated current minimum areal density; Fuel Pool. The results of this analysis showed the lowest B-10 areal density was 0.0257 grn/cm2

The average areal density was 0.0267 gm/cm2 for all the coupons tested. Results of coupon testing of the neutron absorber have provided no indication of loss of neutron absorbing material. Therefore, the estimated current minimum areal density is the

Enclosure to PLA-7 518 Page 5 of 16 same as when the material was fabricated and installed in the SFP.

11. current credited areal density of the neutron-absorbing Criticality analyses have been performed for each material in the NCS AOR; and fuel design utilized at SSES to demonstrate that storage of fuel assemblies of each design in the spent fuel pool high density racks results in Keff <0.95 .

Based on review of the referenced calculations, the following areal density is assumed:

Reference GE-8x8 Fuel- 0.0232grn/cm2 B10 10 Reference AREV A CEXXON>-8x8 Fuel- bounded by 19 GE-8x8 Fuel Reference AREV A (EXXON)-9x9 Fuel - 0.0232grn/cm2 B 10 11 Reference Lead Use Assemblies (LUA)-GE12- 4-bundles 13 (U2C8-10/1995) bounded by AREVA (EXXON)-9x9 Fuel Reference LUA-ABB/Westinghouse SVEA96- 4-bundles 14 (U1C10-10/1996) bounded by AREVA (EXXON)-9x9 Fuel Reference AREVA-ATRIUM10 - 0.0233grn/cm2 B10 12 111. recorded degradation and deformations of the neutron- Reference Coupon Test results:

absorbing material in the SFP (e.g., blisters, swelling, 2,3,17,23 Reference 2 provides the SSES response to the LRA gaps, cracks, loss of material, loss of neutron-attenuation NRC RAI 3.3-1 requested under reference 8.

capability). Within this response, SSES discusses the observed conditions of the vented samples. Some blistering has been observed near the edges of the plate, but neutron attenuation testing has shown the Boral retained its design properties. No issues have been identified with the non-vented co1.1]2_ons. This

Enclosure to PLA-7518 Page 6 of 16 information has not changed based on recent coupon testing performed in 2015.

Reference 3 provides the SSES response to LRA NRC RAI 3.3.2.2.6-5 and 3.3.2.2.6-6 requested under Reference 9. Within this response SSES provides evaluation against the 2003 Seabrook Boral Test Coupon Operating Experience as well as SSES internal Operating Experience with respect to identified poison can bulging in Unit 1 Spent Fuel Storage Pool cell PP-2 and C-13. The EPRI Handbook of Neutron Absorbing Materials for Spent Nuclear Fuel Transportation and Storage Applications 2009 Edition discusses blistering experienced in Boral panels. According to EPRI, no loss of material or impact on areal density has been experienced in observed cases. The issue is cosmetic in nature. SSES stated in reference 3 that the bulging experienced in cell PP-2 and C-13 were isolated incidents and not indicative of a fuel storage rack problem. There have been no changes observed in the conditions discussed in 2009 in response to the RAI in reference 3.

2. Provide a description of the surveillance or monitoring program used to confirm that the credited neutron-absorbing material is performing its safety function, including the frequency, limitations and accuracy of the methodologies used:

a) Provide the technical basis for the surveillance or monitoring Reference 2, SSES Boral sample coupons are a shortened method, including a description of how the method can detect 3, 4, 5, 6, 23, production- type can similar to the spent fuel rack.

degradation mechanisms that affect the material's ability to 24, 25 Half of the Boral coupon inventory are non-vented perform its safety function. Also, include a description and in order to simulated expected conditions where technical basis for the technique(s) and method(s) used in the spent fuel pool is not in contact with the Boral. The surveillance or monitoring program, including: other half are vented to simulate conditions where

i. approach used to determine frequency, calculations, and Boral would be in contact with the water.

sample size; Reference 2 provides the SSES response to LRA NRC RAI 3.3-1 requested under Reference 8.

Reference 3 provides the SSES response to LRA RAI 3.3.2.2.6-3 requested under Reference 9.

Enclosure to PLA-7518 Page 7 of 16 Within these responses the SSES Spent Fuel Pool Boral Coupon test frequency is discussed for both the original operating license and the extended operating license. As discussed, the in-service inspection program was established based on original manufacturer recommendations. Two Boral coupon capsules, one vented to the pool water and one sealed, are shipped from the SSES Spent Fuel Pool to Northeast Technology Corp's (NETCO) laboratory for analysis. Dates and results of previous coupon testing can be found under reference 2. In addition to the original in-service inspection program established, SSES has committed to continuing the coupon testing program in the tenth or eleventh year of extended operation (reference 4 and 5).

SSES Unit 1 and Unit 2 are operated with the spent fuel pools cross-tied. As such, testing a single set of coupons provides representative results for both pools (reference 3).

11. parameters to be inspected and data collected; Reference 2, Reference 2 provides the SSES response to LRA 17,20,25 NRC RAI 3.3-1 requested under Reference 8.

Within this response SSES provides discussion on the Boral Coupon Test program and provides the details on each parameter measured when a coupon is removed. The following examinations and tests are performed:

- Visual examination and high resolution photography

- Inspection of each coupon for anomalies (films, pitting, blisters, discoloration)

- Dry coupon weight-weigh coupon and record dry weight

- Drying and subsequent weighing- dry coupon until no further weight loss is observed

Enclosure to PLA-7 518 Page 8 of 16 Thickness measurement at 5 locations on each coupon

- Neutron attenuation testing for B-10 areal density at 5 locations 111. acceptance criteria of the program and how they ensure Reference 2, Reference 2 provides the SSES response to LRA that the material's structure and safety function are 6 NRC RAI 3.3-1 requested under Reference 8.

maintained within the assumptions of the NCS AOR; Within this response SSES states: "The acceptance criteria of Boral neutron attenuation from the FSAR is Ketr of <0.95 which corresponds to a B-10 areal density of0.0233 g/cm2 ."

Any other anomalies observed will be documented and entered into the corrective action program for evaluation by the engineer and industry experts (as needed).

lV. monitoring and trending of the surveillance or monitoring Reference 2, Reference 2 provides the SSES response to LRA program data; and 17 NRC RAI 3.3-1 requested under Reference 8.

Within this response SSES provides Areal Density Results for each coupon tested from 1985 until 2005. Since providing this information in support of the LRA, SSES has completed 1 additional coupons test.

As discussed above, SSES completed the latest Spent Fuel Pool coupon analysis in September 2015 from the Unit 1 Spent Fuel Pool. The results of this analysis showed the lowest B-1 0 areal density was 0.0257 gm/cm2 . The average areal density was 0.0267 grn/cm2 for all the coupons tested. Results of coupon testing of the neutron absorber have provided no indication of loss of neutron absorbing material. Therefore, the estimated current minimum areal density is the same as when the material was fabricated and installed in the SFP.

v. industry standards used. Reference The following Standards are used by NETCO m 3,18 performing Boral coupon analysis:

Enclosure to PLA-7 518 Page 9 of 16 ASTM C992, "Specification for Boron-Based Neutron Absorbing Materials Systems for Use in Nuclear Spent Fuel Storage Racks" ASTM C1187-15, "Standard Guide for Establishing Surveillance Test Program for Boron-Based Neutron Absorbing Materials Systems for Use in Nuclear Fuel Storage Racks in a Pool Environment."

b) For the following monitoring methods, include these additional Reference Due to the design of the Boral poison cans, a visual discussion items. 15 inspection of the in-service material is not possible.

i. If there is visual inspection of inservice material: The neutron absorbing material is enclosed within

( 1) describe the visual inspection performed on each the panel. Reference the response to 2.a.ii above for sample; and details on the visual inspection during the coupon (2) describe the scope of the inspection (i.e., number evaluation.

of panels or inspection points per inspection period).

n. If there is a coupon-monitoring program: Reference 2, (1) As discussed in reference 2, SSES Boral

( 1) provide a description and technical basis for how 15, 23, 24, sample coupons are a shortened production-the coupons are representative of the material in 27 type can similar to the spent fuel rack. The the racks. Include in the discussion the material coupons meet the same specifications as radiation exposure levels, SFP environment installed in the racks. There are 4 hanger conditions, exposure to the SFP water, location of brackets and there were 8 coupon assemblies the coupons, configuration of the coupons (e.g., per Spent Fuel Pool. They are hung on the jacketing or sheathing, venting bolted on, glued side of Spent Fuel Pool adjacent to storage on, or free in the jacket, water flow past the locations with no poison cans (but not at material, bends, shapes, galvanic considerations, comers of racks). The coupons are and stress-relaxation considerations), and positioned 8 to 10 feet below top of rack dimensions of the coupons; when installed on brackets. Half of the Boral (2) provide the dates of coupon installation for each coupon inventory are non-vented in order to set of coupons; simulated expected conditions where spent (3) if the coupons are returned to the SFP for further fuel pool is not in contact with the Boral.

evaluation, provide the technical justification for The other half are vented to simulate why the reinserted coupons would remain conditions where Boral would be in contact representative of the materials in the rack; and with the water.

(4) provide the number of coupons remaining to be Reference (2) All coupon assemblies were installed same

Enclosure to PLA-7518 Page 10 of 16 tested and whether there are enough coupons for 15 time as racks.

testing for the life of the SFP. Also provide the (3) The SSES Boral Coupon Testing program Reference schedule for coupon removal and testing. requires a destructive examination of the test 18 coupon. As such, the coupons are not returned to the SFP after examination.

(4) There are 2 coupons left at Unit 1 and 3 Reference 3, coupons left at Unit 2. Based on original 6, 17 license commitments, a coupon test is next scheduled for 2023 and will be taken from the Unit 2 Spent Fuel Pool. This will result in 2 sets of coupons remaining at each unit for the period of extended operation. SSES has committed to performing coupon testing on one set of coupons during the tenth or eleventh year after Unit 1 enters the period of extended operation. Upon completion of this test, 3 coupons will remain in the SSES Spent Fuel Pools at the end of the operating license.

111. IfRACKLIFE is used: Reference 7 RACKLIFE is only applicable to the Boraflex neutron absorber material. As discussed above, SSES has only Spent Fuel racks containing Boral.

As such, per Table 1 of Generic Letter 2016-01, item 2(b )(iii) ofthe requested information does not apply.

lV. If in-situ testing with a neutron source and detector is SSES does not perform in-situ testing of the Boral used (e.g., BADGER testing, blackness testing): Racks. As such, Reference 7 Appendix A Section (1) describe the method and criteria for choosing 2.b.iv does not apply.

panels to be tested and include whether the most susceptible panels are chosen to be tested.

Provide the statistical sampling plan that accounts for both sampling and measurement error and consideration of potential correlation in sample results. State whether it is statistically significant enough that the result can be extrapolated to the state of the entire pool; (2) state if the results of the in-situ testing are

Enclosure to PLA-7518 Page 11 of 16 trended and whether there is repeat panel testing from campaign to campaign; (3) describe the sources of uncertainties when using the in-situ testing device and how they are incorporated in the testing results. Include the uncertainties outlined in the technical letter report titled "Initial Assessment of Uncertainties Associated with BADGER Methodology,"

September 30, 2012 (Agencywide Document Access and Management System Accession No. ML12254A064). Discuss the effect of rack cell deformation and detector or head misalignment, such as tilt, twist, offset, or other misalignments of the heads and how they are managed and accounted for in the analysis; and (4) describe the calibration of the in-situ testing device, including the following:

a. describe how the materials used in the calibration standard compare to the SFP rack materials and how any differences are accounted for in the calibration and results;

b. describe how potential material changes in the SFP rack materials caused by degradation or aging are accounted for in the calibration and results; and

c. if the calibration includes the in-situ measurement of an SFP rack "reference panel," explain the following:

i. the methodology for selecting the reference panel(s) and how the reference panels are verified to meet the requirements; n . whether all surveillance campaigns use the same reference panel(s); and iii. if the same reference panels are not

Enclosure to PLA-7 518 Page 12 of 16 used for each measurement surveillance, describe how the use of different reference panels affects the ability to make comparisons from one campaign to the next.

3. Provide a description of the technical basis for determining Reference 7 As discussed above, SSES has only Spent Fuel racks the interval of surveillance or monitoring for the credited containing Boral. As such, per Table 1 of Generic neutron-absorbing material: Letter 2016-01, item 3 of the requested information does not apply.

4. Provide a description of how the credited neutron-absorbing material is modeled in the SFP NCS AOR and how the monitoring or surveillance program ensures that the actual condition of the neutron-absorbing material is bounded by the NCS AOR:

a) Describe the technical basis for the method of modeling the Reference The technical basis behind General Electric's (GE) neutron-absorbing material in the NCS A OR. Discuss whether the 6,10,11,12 and AREVA's method of modeling the neutron-modeling addresses degraded neutron-absorbing material, absorbing material is the SSES FSAR (reference 6).

including loss of material, deformation of material (such as The following reflects the FSAR discussion:" ... a blisters, gaps, cracks, and shrinkage), and localized effects, such uniform minimum B 10 areal density of 0.0233 as non-uniform degradation. gm/cm2 . .. . Benchmark measurements in (Susquehanna) Boral slabs yield a neutron attenuation factor of0.963 minimum." A B10 loading of0.0233 gm/cm2 , producing an attenuation factor of 0.963, yielded aBoral core thickness of 0.055 +/- 0.003 inches. This is less than the Boral nominal thickness of 0.080 inches.

Reference Degraded neutron-material is not addressed within 6, 12 any SSES Criticality Safety Analysis. Per the SSES FSAR (9 .1.2.3 .1 Criticality Control), the spent fuel storage pool has also been analyzed under abnormal and accident conditions. These conditions included a fuel bundle placed vertically along the edge of the spent fuel pool, a fuel bundle laid horizontally on the top of the spent fuel pool racks, and a single missing Boral panel from the storage array. For all normal, abnormal, and accident conditions, the spent fuel pool rack keff remained less than 0.95.

Enclosure to PLA-7 518 Page 13 of 16 b) Describe how the results of the monitoring or surveillance Reference Per the SSES SFP Surveillance Coupon Analysis program are used to ensure that the actual condition of the 20 procedure, the average B 10 areal densities, from all neutron-absorbing material is bounded by the SFP NCS AOR. If a coupon surveillances, are plotted versus the sample coupon monitoring program is used, provide a description and date. A linear regression is then performed to technical basis for the coupon tests and acceptance criteria used to determine if the trended B 10 areal density will reach ensure the material properties of the neutron-absorbing material its minimum allowed value during the time interval are maintained within the assumptions of the NCS AOR. Include to the next scheduled testing.

a discussion on the measured dimensional changes, visual inspection, observed surface corrosion, observed degradation or The coupon analysis determines the effect a high deformation ofthe material (e.g., blistering, bulging, pitting, or radiation field (e.g., neutron and gamma) has on warping), and neutron-attenuation measurements of the coupons. BORAL' and confirms the assumptions made in the FSAR (Reference 6). The acceptance criteria compares the FSAR 0.0233 gm/cm2 BlO areal density to that from the coupon analyzed by the vendor. This data is then plotted to determine if the B 10 areal density will reach its minimum allowed value during the time interval to the next scheduled testing.

The SSES Criticality Safety Analysis does not evaluate any measured dimensional changes, visual inspections, surface conditions and other general degradations of the neutron-absorbing material. The only verification is comparing the FSAR minimum 0.0233 gm/cm2 BlO areal density to that from the coupon analyzed by the vendor.

c) Describe how the bias and uncertainty of the monitoring or Bias and uncertainty of the monitoring or surveillance program are used in the SFP NCS AOR. surveillance program (the SFP Surveillance Coupon Analysis procedure) are not addressed within any SSES Criticality Safety Analysis.

d) Describe how the degradation in adjacent panels is correlated and Reference The SSES Criticality Safety Analysis DOES evaluate accounted for in the NCS AOR. 6, 10, 11,12 a single missing Boral panel from the storage array, but it does NOT address degradation in adjacent panels. - -

Enclosure to PLA-7 518 Page 14 of 16

5. Provide a description of the technical basis for concluding Reference 7 As discussed above, SSES has only Spent Fuel racks I that the safety function for the credited neutron-absorbing containing Boral. As such, per Table 1 of Generic material in the SFP will be maintained during design-basis Letter 2016-01, item 5 of the requested information events. does not apply.

Enclosure to PLA-7518 Page 15 ofl6 References The following references support the SSES responses provided for the requested information in Generic Letter 2016-01.

1. PLA-6110, "Susquehanna Steam Electric Station Application for Renewed Operating Licenses Numbers NPF-14 and NPF-22," September 13,2006 (ADAMS Accession No. ML062630225).

2. PLA-6401 , "Susquehanna Steam Electlic Station Request for Additional Information for the Review of the Susquehanna Steam Electric Station Units 1 and 2, License Renewal Application (LRA) Section 3.1 , 3.2, 3.3, and 3.4," August 15, 2008 (ADAMS Accession No. ML082400534) .

3. PLA-6504, "Susquehanna Steam Electric Station Request for Additional Information for the Review of the Susquehanna Steam Electric Station Units 1 and 2, License Renewal Application (LRA) Section 3.3.2.2.6," May 13, 2009 (ADAMS Accession No. ML091520031).

4. PLA-6518, "Susquehanna Steam Electric Station Units 1 and 2, License Renewal Application (LRA) Amendment to LRA Commitment #61 ," May 28,2009 (ADAMS Accession No. ML091590040).

5. NUREG-1931, "Safety Evaluation Report Related to the License Renewal of Susquehanna Steam Electric Station, Units 1 and 2, Docket Nos. 50.387 and 50.388,"

November 2009 (ADAMs Accession No. ML093170780).

6. Susquehanna Steam Electric Station Final Safety Analysis Report (FSAR), Section 9.1.2, Spent Fuel Storage.

7. NRC Generic Letter 2016-01, "Monitoring ofNeutron-Absorbing Materials in Spent Fuel Pools," April 7, 2016.

8. Letter from Ms. E. H. Gettys (USNRC) to Mr. B. T. McKinney (PPL), "Request for Additional Information for the Review of the Susquehanna Steam Electric Station, Units 1 and 2 License Renewal Application," dated July 15, 2008 (ADAMs Accession No. ML081780698).

9. Letter from Ms . E. H. Gettys (USNRC) to Mr. W. H. Spence (PPL), "Request for Additional Information for the Review of the Susquehanna Steam Electric Station, Units 1 and 2 License Renewal Application," dated April 13, 2009 (ADAMs Accession No. ML091030296).

10. M . L Kennedy and C. Ho, Nuclear Criticality Analysis for the Spent Fuel Racks of the Susquehanna Power Plant," NAI 78-75 Revision 3, Nuclear Associated International, March 31, 1981.

11. "Criticality Safety Analysis Susquehanna Spent Fuel Storage Pool with Exxon Nuclear Company, Inc. 9x9 Reload Fuel (March 1986)," XN-NF-86-45 , Revision 1, Exxon Nuclear Company, Inc., May 1986.

Enclosure to PLA-7518 Page 16of16

12. "Susquehanna Spent Fuel Storage Vault Criticality Safety Analysis for ATRIUM-10 Fuel," EMF-96-136(P), Revision 0, Siemens Power Corporation, Nuclear Division, October 1996.

13. "Susquehanna Steam Electric Station, Unit 2 Cycle 8 Reload Summary Report,"

PL-NF-95-007, Revision 2, PP&L, August 1996.

14. "Susquehanna Steam Electric Station, Unit 1 Cycle 10 Reload Summary Report,"

PL-NF-96-005, Rev 2, PP&L, July 1997.

15. Specification, 8856-M-192, "Technical Specification for High Density Spent Fuel Storage Racks for the Susquehanna Steam Electric Station Units 1 and 2 of the PP&L Company," Revision 4, May 12, 1980.

16. PaR QCP-82-4, "Specification for Neutron Absorber Plates for SSES Units 1 and 2,"

FF107400 Sheet 0901.

17. SE-036-001, "Spent Fuel Pool Surveillance Coupon Analysis," Work Order Number RTSV 1467487, Completed on 9/2/2015 .

18. SEP-28076-000-01, Special Engineering Procedure, "Procedures for Measuring and Recording Boral Surveillance Coupon Physical Attributes," NETCO, Rev 1, 3/3/15.

19. "Susquehanna SES Unit 1 Cycle 2 Reload Summary Report," NPE-84-015, PP&L, December 1984.

20. Procedure, SE-036-001, "Spent Fuel Pool Surveillance Coupon Analysis," Rev 5.

21. "Boral Neutron Absorbing. Shielding Material, Product Performance Report" AAR Brooks & Perkins Corp., Report 624, July 20, 1982 (ML050420037).

22. 8856-M192-113-2, Revision 2, "Boral Requalification Procedure for PaR Systems Corp.," FF107401 , Sheet 1301.

23 . "Handbook of Neutron Absorber Materials for Spent Nuclear Fuel Transportation and Storage Applications," EPRI, Palo Alto, CA: 2009. 1019110.

24. Drawing, M192-135, "Test Coupon Assembly for Spent Fuel Storage Racks," FF107401, Sheet 3501.

25 . 8856-M192-129-3, "Coupon Checking Instructions for Test Coupon Assemblies PaR Job No. 3157." FF107401 , Sheet 2901.

26. Drawing, M192-134, "Boral Shearing and Sampling Sketch for Spent Fuel Storage Racks," FF107401, Sheet 3401.

27. Drawing, M192-137, "Test Coupon Installation for Spent Fuel Storage Rack," FF107401, Sheet 3701 .

28. NRC Inspection Report, 50-387/ 83-06, 50-388/ 83-03, Dated April15, 1983.