ML20203E331
| ML20203E331 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 12/05/1997 |
| From: | Salas P TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEIN-97-077, IEIN-97-77, NUDOCS 9712170020 | |
| Download: ML20203E331 (5) | |
Text
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Tennessee Valley Authority, Post Omce Box 2000, Soddy-Daey, Tennessee 37379-2000 December 5, 1997 U.S. Nuclear Regulatory Commission 10 CFR 70.14(a)
ATTN:
Document Control Desk-10 CFR 70.24(a)
Washington, D.C.
20555 10 CFR 70.24(d)
Gentlemen:
In the Matter of
)
Docket Nos. 50-327 Tennessee Valley Authority
)
50-328 SEQUOYAH NUCLEAR PLANT (SQN) - UNITS 1 AND 2 - REQUEST FOR EXEMPTION FROM 10 CFR 70.24 CRITICALITY MONITORING REQUIREMENTS TVA is submitting a revised request for an exemption from the requirements of 10 CFR 70.24(a), " Criticality Accident Requirements," for SCN Units 1 and 2.
This revised request addresses-the criteria included in NRC Information Notice 97-77 dated October 10, 1997.
This request involves no changes to radiation monitoring instrumentation or emergency plan procedures presently utilized at SON.
Specific exemptions from 10 CFR 70.24 were previously granted in the construction phase special nuclear material (SNM) licenses for each unit (SNM-1716 and SNM-1863).
The basis for this revised exemption request is detailed in the attached enclosure and meets-the good cause requirements outlined in 10 CFR 70.24 (d).
TVA believes the request is appropriate for the same reasons as the original SNM licenses exemption.
Further, the proposed exemption is authorized by law and will not endanger life or property or the common defense and security, and-is otherwise in the public interest.
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U.S.
Nuclear Regulatory Commission Page 2 Decembhr 5, 1997 If you have any questions about this exemption request, please telephone me at (423) 843-7170 or J.
D.
Smith at (423) 843-6672.
Si el h... _..-f~
o Salas Manager of Licensing and Industry Affairs Enclosure cc (Enclosure):
Mr.
R.
W.
Hernan, Project Manager Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 NRC Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy-Daisy, Tennessee 37379-3624 Regional Administrator U.S.
Nuclear Regulatory Commission Region II Atlanta Federal Center 61 Forsyth St.,
SW, Suite 23T85 Atlanta, Georgia 30323-3415
ENCLOSURE-TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN)
UNITS 1 AND 2 REQUEST FOR EXEMPTION FRON 10 CFR 70.24 (a)-
CRITICALITY ACCIDENT REQUIREMENTS I.
EXEMPTION REQUESTED AND REGULATORY BACKGROUND Pursuant to 10 CFR 70.14 (a) and 70.24 (d), TVA requests an exemption f rom the requirements of 10 CFR 70.24 (a)
" Criticality Accident Requirements," for SON Units 1 and 2.
Specifically, TVA request an exemption for accident criticality monitoring for the handling, use, and storage of special nuclear material (SNM).
The SNM is in the-form of nuclear fuel, calibration sources, and neutron monitoring instrumentation (such as source range monitors
[SRMs), intermediate range monitors [IRMs], and incore fission detectors).
10 CFR 70.24(d) anticipates that licensees may request relief from the requirements of Section 70.24, in whole or in part, if good cause is shown 10 CFR 70.24(c) states that holders of Part 50 operating licenses are exempt from 10 CFR 70.24 (b) provisions.
Therefore, only an exemption to section 70.24 (a) is being requested.
The criteria included in NRC 'aformation Notice 97-77 dated October 10, 1997, serves as ene basis for this request.
Previous exemptions from 10 CFR 70.24 were granted in the construction phase SNM licenses for each unit (SNM-1716 and SNM-1863).
TVA believes an exemption continues to ae appropriate for the same reasons as for the exemption granted in the original SNM licenses.
An accident criticality monitoring system was not and is not necessary at SON.
II.
JUSTIFICATION FOR THE EXEMPTION SNM in Calibration Sources and Neutron Monitoring Instrumentation The major form of SNM used at SON is nuclear fuel.
However, other small quantities of SNM are in the form of fissile material in calibration sources and neutron monitoring instrumentation.
The quantity of SNM U-235 in E-l
each flux detector (SRM/IRM) and incore detector is small (7 grams and 4 milligrams, respectively).
SON also has sev,eral calibration sources containing very small amounts of plutonium-239 totaling approximately 0.02 milligrams.
The quantity of SNM specified to be sufficient for a critical mass is 350 grams of U-235, 200 grams of U-233, and 200 grams of Pu-239.
Regulatory Guide 10.3, " Guide for the Preparation of Applications for Special Nuclear Material Licenses of Less than Critical Mass Quantities,"
Section 1.1 specifies these quantities.
The quantities of SNM in the nuclear instrumentation described above is far below the amounts for which criticality monitoring would be of concern.
SNM In Unirradiated Nuclear Fuel The principal form of SNM subject to 10 CFR 70.24 (a) is unirradiated (new) nuclear fuel.
The maximum U-235 enrichment for new fuel is 5.00 weight percent.
New fuel bundles are transported and received in NRC approved packaging (commonly referred to as shipping containers).
The shipping container's design provides a geometrical criticality safe configuration during transport, handling, and storage.
Storage of new fuel may be in the new fuel storage vault or in the spent fuel pool.
Section 9.1 of the Fir 31 Safety Analysis Report (FSAR) and Section 5.6.1.2 of the SON technical specifications (TS) provides the design basis and description of the new fuel storage racks and the spent fuel pool storage racks.
The racks are individual vertical cells fastened together in a 4 x 5 array forming modules that are firmly bolted to embedded plates in the floor of the new fuel vault.
The fuel racks, including supports, are austenitic stainless steel.
The fuel racks construction is such that it is impossible to insert fuel assemblies, except in prescribed locations.
The fuel racks have a minimum center-to-center spacing of 21 inches in both directions.
The spacing is sufficient to assure K.n less than 0.95 even if immersed in unborated water or Ken less than 0.98 if optimally moderated by being enveloped by an aqueous foam or mist with a minimum of a 95 percent probability and 95 percent confidence level.
Section 4.3 of the FSAR provides a description of the criticality of fuel assemblies.
The design of the new fuel storage racks is in accordance with AISC, Sixth Edition, 1963.
The design of the new fuel storage vault is in accordance with ACI318-1963.
Following receipt of new fuel shipments, the containers are opened for an inspection of the bundles and placed directly E-2
e in the new fuel vault or in the spent fuel pool.
Site fuel handling procedures carefully control handling of new fuel and irradiated fuel.
New fuel assemblies are removed one at'a time'from the shipping cask and normally stored dry in the fuel storage racks located in the fuel storage area.
Given these circumstances, a criticality safe configuration is maintained and there is no need to maintain a criticality monitoring system pursuant to 10 CFR 70.24.
Two area-type radiation moritors are in the system to monitor the fuel pool air space.
These monitors would measure dose rates during any fuel handling accident or criticality accident.
Upon excessive radiation levels being detected plant personnel would initiate appropriate safety actions.
This exemption request involves no changes to radiation monitoring instrumentation, plant equipment, or emergency plan procedures presently utilized at SON, and does not involve changes to safety analyses found in Chapter 15 of the FSAR.
Also, this exemption request does not involve changes to current TS requirements related to fuel handling, or involve changes to operations related to the spent fuel pool or criticality monitoring of fuel in the reactor core.
Based on the above, the design of the shipping containers and fuel racks, in combination with the procedural controls associated with fuel handling, preclude conditions that may lead to accidental criticality.
Accordingly, approval of the exemption request will not endanger life or property or be inimical to the common defense and security.
Thus, we believe the exemption is authorized by law, and there is good cause for granting an exemption for accident criticality monitoring requirements for SON.
Granting of an exemption is consistent with the same exemption granted from 10 CFR 70.24 in the original construction phase SNM licenses.
III.
CONCLUSION TVA has concluded, based on the preceding justification, that operation of SON, in accordance with the proposed exemption to 10 CFR 70.24 (a), is authorized by law.
The approval of the exemption request will not present an undue risk to the public health and safety, is consistent with the common defense and security, and is otherwise in the public interest.
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