ML19211B509
| ML19211B509 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim (DPR-035) |
| Issue date: | 07/30/2019 |
| From: | Gaston R Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 2.19.049 | |
| Download: ML19211B509 (6) | |
Text
Entergy Nuclear Operations, Inc.
1340 Echelon Parkway Jackson, MS 39213 Tel 601-368-5138 Ron Gaston Director, Nuclear Licensing 10 CFR 50.12 10 CFR 50.54(w)(1) 10 CFR 140.8 10 CFR 140.11(a)(4) 2.19.049 July 30, 2019 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
SUBJECT:
Supplement to Requests for Exemption from 10 CFR 50.54(w)(1), Concerning On-Site Property Damage Insurance and from 10 CFR 140.11(a)(4), Concerning Primary and Secondary Liability Insurance Pilgrim Nuclear Power Station NRC Docket No. 50-293 Renewed Facility Operating License No. DPR-35
References:
- 1) Entergy letter to NRC, "Request for Exemption From 10 CFR 50.54(w)(1)," (ADAMS Accession No. ML19088A050), dated March 25, 2019
- 2) Entergy letter to NRC, "Request for Exemption From 10 CFR 140.11(a)(4), (ADAMS Accession No. ML19088A127), dated March 25, 2019
- 3) NRC SECY-93-127, "Financial Protection Required of Licensees of Large Nuclear Power Plants During Decommissioning," (ADAMS Accession No. ML12257A628), dated May 10, 1993
- 4) NRC Staff Requirements Memorandum for SECY-93-127, (ADAMS Accession No. ML003760936), dated July 13, 1993 On March 25, 2019, Entergy Nuclear Operations, Inc. (Entergy) submitted requests for permanent exemption from 10 Code of Federal Regulations (CFR) 50.54(w)(1) (Reference 1) and 10 CFR 140.11(a)(4) (Reference 2) for Pilgrim Nuclear Power Station (PNPS). These requests were made pursuant to 10 CFR 50.12, and 10 CFR 140.8, "Specific exemptions,"
respectively.
2.19.049 Page 2 of 2 Based upon feedback from the NRC and further review of industry precedent, an area requiring further information was identified. The information concerns a demonstration that the spent fuel could be air cooled if the spent fuel pool was fully drained. In SECY-93-127 (Reference 3), the NRC staff considered potential financial liability of a zirconium fire to determine that the overall risk at decommissioning plants does not justify the full insurance coverage once the spent fuel has sufficiently decayed. In its Staff Requirements Memorandum for SECY-93-127 (Reference 4), the Commission approved a policy that authorized reductions in commercial liability insurance coverage through the exemption process after the spent fuel had undergone an appropriate period of cooling, which the NRC staff defined as when the spent fuel could be air-cooled if the spent fuel pool was drained of water.
Therefore, Entergy is providing supplemental information in the Enclosure.
If you have any questions regarding this information, please contact Mr. Peter J. Miner at 508-830-7127.
This letter contains no new regulatory commitments.
Respectfully, Ron Gaston RG/rjm
Enclosure:
Supplement to Requests for Exemption from 10 CFR 50.54(w)(1), Concerning On-Site Property Damage Insurance and from 10 CFR 140.11(a)(4), Concerning Primary and Secondary Liability Insurance cc:
NRC Region I, Regional Administrator NRC NRR Project Manager - Pilgrim NRC Senior Resident Inspector - Pilgrim
Enclosure 2.19.049 Supplement to Requests for Exemption from 10 CFR 50.54(w)(1), Concerning On-Site Property Damage Insurance and from 10 CFR 140.11 (a)(4), Concerning Primary and Secondary Liability Insurance
2.19.049 Enclosure Page 1 of 3 Supplement to Requests for Exemption from 10 CFR 50.54(w)(1), Concerning On-Site Property Damage Insurance and from 10 CFR 140.11(a)(4), Concerning Primary and Secondary Liability Insurance I.
BACKGROUND On March 25, 2019, Entergy Nuclear Operations, Inc. (Entergy) submitted requests for permanent exemption from 10 Code of Federal Regulations (CFR) 50.54(w)(1) (Reference 1) and 10 CFR 140.11(a)(4) (Reference 2) for Pilgrim Nuclear Power Station (PNPS). These requests were made pursuant to 10 CFR 50.12, and 10 CFR 140.8, "Specific exemptions,"
respectively.
Based upon feedback from the NRC and further review of industry precedent, an area requiring further information was identified. The information concerns a demonstration that the spent fuel could be air cooled if the spent fuel pool was fully drained. In SECY-93-127, "Financial Protection Required of Licensees of Large Nuclear Power Plants During Decommissioning,"
(Reference 3), the NRC staff considered decommissioning plants potential financial liability and the low likelihood and reduced short-term public health consequences of a zirconium fire to determine that the overall risk at decommissioning plants does not justify the full insurance coverage that operating reactors have once a decommissioning plant's spent fuel has sufficiently decayed. In its Staff Requirements Memorandum for SECY-93-127 (Reference 4),
the Commission approved a policy that authorized reductions in commercial liability insurance coverage through the exemption process after the spent fuel had undergone an appropriate period of cooling, which the NRC staff defined as when the spent fuel could be air-cooled if the spent fuel pool was drained of water.
II.
TECHNICAL EVALUATION Entergy has compiled data comparing the input parameters to the representative NRC generic Analyses (NUREG/CR-6451, 1997, Reference 5) to the data for PNPS. Specifically, Tables 1 and 2 provide compiled data comparing the input parameters for PNPS to the input parameters for the representative Boiling Water Reactor (BWR). As indicated, PNPS fuel assemblies have a three month longer decay period resulting in a 23 percent reduction in decay heat. This reduction offsets the potential 26 percent increase in heat load due to higher fuel assembly burnup.* It is noted that this comparison conservatively uses the maximum burnup value based on a 99.8 percent capacity factor. It is also noted that there are significantly less hot assemblies in the PNPS spent fuel pool compared to the representative BWR. Based on these considerations, it is concluded that the PNPS spent fuel pool conditions are bounded by the NUREG/CR-6451 benchmark values, demonstrating that the PNPS spent fuel pool can be air cooled after 10 months following permanent shutdown.
- Net change = Max Burnup Increase x Decay Time Reduction
= (1 + 0.26) (1 - 0.23)
= 0.97 [i.e., net decrease]
2.19.049 Enclosure Page 2 of 3 Table 1 - NUREG/CR-6451 Spent Fuel Zirconium Fire Comparison Item Parameter NUREG/CR-6451 Model Plant Value PNPS Value (Reference)
Difference 1
Plant Data a) Power b) Assemblies c) MWt/Assembly a) 3300 MWt b) 764 c) 4.3 a) 2028 MWt (UFSAR, Table 3.7-1) b) 580 (UFSAR, Pg. 1.6-4) c) 3.5 (Calculated) 184 less hot assemblies; 19% lower power density and associated decay heat (Ref. 8) 2 Spent Fuel Pool Storage Data a) Total Capacity b) Quantity in SFP a) 3300 b) 3300 a) 3859 (UFSAR, Pg. 10.3-2) b) 2958 (Physical Inventory) 342 less bundles adding heat; more air flow passages 3
SFP Rack Design a) Design b) Material c) Pitch d) Orifice Size a) High Density b) Stainless Steel c) 6.255 d) 4 a) High Density (UFSAR, Pg. 10.3-5) b) Stainless Steel (Rack Drawings) c) 6.257 Boral/Metamic - 5 Racks 6.243 Boraflex - 9 Racks (Rack Drawings) d) 3.625 Boral/Metamic 3.75 Boraflex (Rack Drawings)
Pitch:
0.002 larger spacing 0.007 smaller spacing Orifice:
Bounded by maximum fuel orifice size = 3.505 (Fuel Bundle Drawings) 4 Fuel Max Assembly Burnup 40 GWD/MTU 50.43 GWD/MTU (Ref. 6) based on capacity factor = 99.8%
(Ref. 7);
49.30 GWD/MTU based on actual Cycle 22 capacity factor = 81.95%
Potentially up to 26%
higher heat due to increased max assembly burnup (conservatively using 99.8% capacity factor) 5 Source Term Decay 7 Months 10 Months (Ref. 1, 2) 23% less decay heat contribution from hot bundles due to longer source term decay time (Ref. 8) 6 Zirconium Oxidation Temperature Limit 565o C 565o C Same
2.19.049 Enclosure Page 3 of 3 TABLE 2 - NUREG/CR-6451 Power Density Comparison Item Parameter NUREG/CR-6451 Model Plant Value PNPS Value (Reference)
Difference 1
Power per Assembly (MWt/Assembly) 4.3 3.5 (Ref. 8)
Lower power density 2
Fuel Assembly Width (inches) 5.28 5.28 (Ref. 6) 3 Fuel Active Height (inches) 145.24 145.24 (Ref. 6) 4 Active Volume (in3 [m3])
4049.1 [0.0664]
4049.1 [0.0664]
5 Power Density (MWt/m3) 64.8
52.7 REFERENCES
- 1) Entergy letter to NRC, "Request for Exemption From 10 CFR 50.54(w)(1)," (ADAMS Accession No. ML19088A050), dated March 25, 2019
- 2) Entergy letter to NRC, "Request for Exemption From 10 CFR 140.11(a)(4)," (ADAMS Accession No. ML19088A127), dated March 25, 2019
- 3) SECY-93-127, "Financial Protection Required of Licensees of Large Nuclear Power Plants During Decommissioning," (ADAMS Accession No. ML12257A628), dated May 10, 1993
- 4) Staff Requirements Memorandum for SECY-93-127, (ADAMS Accession No. ML003760936), dated July 13, 1993
- 5) NUREG/CR-6451 "A Safety and Regulatory Assessment of Generic BWR and PWR Permanently Shutdown Nuclear Power Plants," dated April 1997
- 6) Entergy letter to NRC, "Response to Request for Additional Information - Exemption from the Requirements of 10 CFR 50.47 and Appendix E to 10 CFR Part 50," (ADAMS Accession No. ML19056A192), dated February 18, 2019
[Attachment 2, Calculation No. PNPS-EC-73355-M1418, Revision 1]
- 7) Entergy letter to NRC, "Request for Exemptions from Portions of 10 CFR 50.47 and 10 CFR Part 50, Appendix E," (ADAMS Accession No. ML18186A635), dated July 3, 2018
[Attachment 3, Calculation No. PNPS-EC-73355-M1417]
- 8) Entergy Calculation M1423, "Spent Fuel Pool Decay Heat and Heatup Times After Shutdown," Rev. 1