ML18067A624
| ML18067A624 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 07/02/1997 |
| From: | Bordine T CMS ENERGY CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9707110211 | |
| Download: ML18067A624 (11) | |
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A CMS Energy Company July 2, 1997 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT Thomas c. Bordlne Manager Licensing REQUEST FOR EXEMPTION FROM 10 CFR 70.24(a) REGARDING NUCLEAR CRITICALITY MONITORING Attached is a request for exemption from the provisions of 10 CFR 70.24(a) which relates to monitoring and associated emergency procedures for inadvertent criticality in new fuel storage facilities. This request is submitted in accordance with 10 CFR 70.14(a).
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This request is the result of a recent NRC decision that a plant-specific exemption is necessary. This request is similar to requests reviewed and granted by NRC for a
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number of licensees, including the Donald C. Cook Plant (Dockets 50-315 and 316) on October 28, 1996.
It is requested that this issue be given prompt NRC attention. This exemption is needed prior to receipt in early 1998 of new fuel for the next operating cycle.
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Palisades Nuclear Plant
- 27780 Blue Star Memorial Highway
- Covwl, Ml 49043
- Tel: 616 764 2913
- Fax: 616 764 2490 It@/
SUMMARY
OF COMMITMENTS This letter contains no new commitments and no revisions to existing commitments.
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Thomas C. Bordine Manager, Licensing CC: Administrator, Region Ill, USNRC Project Manager, NRR, USNRC NRC Resident Inspector - Palisades Director, Office of NMSS Attachment 2
CONSUMERS ENERGY COMPANY To the best of my knowledge, the contents of this request for exemption from 10 CFR 70.24(a), are truthful and complete.
Thomas C. Berdine Manager, Licensing Sworn and subscribed to before me this,).,.,.,./ day of _\\.\\
___ ~~-t:::::.--1997.
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Alora M. Davis, Notary Public Berrien County, Michigan (Acting in Van Buren County, Michigan)
My commission expires August 26, 1999
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[SEAL]
ATTACHMENT PALISADES PLANT REQUEST FOR EXEMPTION FROM 1 OCFR70.24(a) 7 Pages
I.
BACKGROUND This proposed exemption request applies to 1 OCFR70.24. 1 OCFR70.24(a) states the requirements for a monitoring system that will energize clearly audible alarms if accidental criticality occurs in each area in which special nuclear material (SNM) is handled, used, or stored. Also, 1 OCFR70.24(a) requires that emergency procedures be maintained for each area in which licensed SNM is handled, used or stored to ensure that all personnel withdraw to an area of safety upon the sounding of the alarm.
These procedures must include the conduct of drills to familiarize personnel with the evacuation plan, designation of responsible individuals for determining the cause of the alarm, and placement of radiation survey instruments in accessible locations for use in such an emergency.
The exemption from 1 OCFR70.24(a) is requested on the basis that the specific requirements contained therein are not necessary to assure safe use, storage, and handling of special nuclear material for the Palisades Plant. The design and operating requirements of the plant operating license and 1 OCFR50 adequately assure public health and safety, and the additional burden of complying with 1 OCFR70.24(a) is not necessary.
II.
JUSTIFICATION FOR GRANTING THE EXEMPTION The specific requirements for granting exemptions from Part 70 regulations are set forth in 10CFR70.24(d) and 10CFR70.14(a). Section 70.24(d) anticipates that licensees may need relief from Section 70.24(a) and allows licensees to apply for an exemption from 1 OCFR70.24, in whole or in part, if "good cause" is shown. Palisades Nuclear Plant believes that good cause exists based on the positions presented below in the context of the requirements of 1 OCFR70.14(a).
Under Section 70.14(a), the Commission i~ authorized to grant an exemption upon a demonstration that the exemption: (A) is authorized by law; (8) will not endanger life or property or the common defense and security; and (C) is in the public interest. The following justifications address each of these requirements.
A.
The Exemption Is Authorized By Law The Commission's authority to grant requests for exemptions from its regulations has existed since 1956. The particular authority to grant exemptions from the requirements of Part 70 was codified in 1 OFCR70.14 in 1972. See 37 Federal Register 57 45, 57 49 (March 21, 1972). Therefore, exemption requests are explicitly authorized under NRC regulations.
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B.
- The Exemption Will Not Endanger Life Or Property Or The Common Defense And Security An exemption request will not endanger life or property or the common defense and security if it can be shown that the request meets the statutory standard of adequate protection to the health and safety of the public. Furthermore, to ensure the common defense and security are not endangered, the exemption request must demonstrate that the loss or diversion of SNM is precluded. In light of these standards, we describe below how the use, storage, and handling of SNM at the Palisades Nuclear Plant provides adequate protection to assure the health and safety of the public, and precludes loss or diversion of SNM.
- 1.
Use Of SNM SNM is present principally in the form of nuclear fuel. However, other quantities of SNM are used (and stored) at the Palisades Nuclear Plant in the form of fissile material incorporated primarily into fission chamber detectors and Pu-Be sources. The small quantity of SNM present in these detectors and sources, and the form in which the SNM is used and stored precludes an inadvertent criticality. The facilities are exempt from Section 70.24(b) for SNM "used or to be used in the reactor pursuant to Section 70.24(c). Thus, this exemption request is directed only toward the requirements of 70.24(a).
Inadvertent or accidental criticality in the reactor vessel is precluded through compliance with the facility technical specifications, including reactivity requirements (e.g., shutdown margins and limits on control rod movement), instrumentation requirements (e.g., power and radiation monitors), and controls on refueling operations (e.g., refueling boron concentration and source range monitor requirements). In addition, the operators' continuous attention directed toward instruments monitoring behavior of the nuclear fuel in the reactor assures that the facility is operated in such a manner as to preclude inadvertent criticality. Finally, since access to the fuel in the reactor vessel is not physically possible while in use and is procedurally controlled during refueling (see Section 11.B.3 below), there are no concerns associated with loss or diversion of the fuel.
Therefore, the requirements of Section 70.24(a) are not necessary for SNM in the form of nuclear fuel while used in the reactor vessel, and thus, granting this exemption will not endanger life or property or the common defense and security.
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- 2.
Storage Of SNM SNM, as nuclear fuel, is stored in either the spent fuel pool or the new fuel storage racks. The spent fuel pool is used to store irradiated fuel under water after its discharge from the reactor and new fuel prior to loading into the reactor. The spenUnew fuel storage area has two permanently installed radiation instruments to monitor area radiation levels. The area monitors are set to alarm at 15 mrem/hr. This is sufficient to meet the intent of 10 CFR Part 50, Appendix A, General Design Criterion 63, for fuel storage areas.
The spent fuel pool is designed to store the fuel in a geometric array that precludes criticality. In addition, existing technical specification limits maintain the effective neutron multiplication factor, Ke"' at less than or equal to 0.95.
The new fuel storage racks may be used to receive and store new fuel in a dry condition upon arrival on site and prior to loading in the reactor or spent fuel pool. The introduction and retention of moderators into the New Fuel Storage Racks at Palisades is prevented by the design of the storage area. The storage area does not have a floor, thus allowing a moderator to freely pass to the next lower level of the Auxiliary Building.
This design precludes the possibility of flooding in the new fuel storage area. Even if optimum moderation is assumed, however, analyses conforming to NRG Standard Review Plan Section 9.1.1, "New Fuel Storage," have shown that the Palisades Nuclear Plant new fuel storage racks will meet the above acceptance criteria.
The new fuel storage racks have been analyzed for a maximum enrichment of 4.25 wt. % including an enrichment uncertainty/tolerance of 0.05 wt. %. Assemblies enriched to 4.20 wt. % (nominal) can be stored in the new fuel storage array and continue to meet the reactivity limit criterion (keff ~ 0.95) stipulated for the storage of new fuel by the Technical Specifications. The criticality analysis demonstrates the storage array to have an effective multiplication factor of< 0.95 for assumed worst credible array conditions of fuel assembly spacing and uniformly dispersed moderation. In determining the maximum array reactivity (keff) for 4.25 wt. % 235U fuel, this analysis evaluated the effects of varying moderator density and fuel assembly spacing within the rack.
All rack conditions were found to have an acceptable reactivity of Ke" <
0.95 after accounting for uncertainties and bias. The maximum Ke" at the 95% confidence level was 0.945. The highest calculated reactivity occurs when the array is fully flooded with water. In the future, if any fuel 3
- enrichment increase in excess of the currently analyzed value is proposed, an analysis similar to the one described above would have to be completed to verify all NRC requirements and plant 1 OCFR50.2 Design Bases continue to be satisfied.
Furthermore, it should be noted that an accidental criticality monitoring system does not ensure against the loss or diversion of SNM material.
The physical security requirements of the plant operating license provide the necessary assurance; consequently, the presence or absence of a criticality monitoring system does not affect the capability of the Palisades Nuclear Plant to ensure SNM is safeguarded.
Overall, the amount of special nuclear material (SNM) other than fuel which is stored on-site is negligible compared to the fuel; it consists of neutron detectors (fission chambers) and Pu-Be neutron sources. The following table illustrates the non-fuel SNM which is typically present on the plant site.
Typical Non-Fuel Special Nuclear Material At The Palisades Site Item Description Location Serial Number Isotopes [grams) 23su 23LJ 23sPu 241Pu Fission Chamber Reactor S/N-009 7
1 Fission Chamber Reactor S/N-010 7*
1 Fission Chamber Reactor S/N-D1010 14 1
Detector Assembly Flatbed Filter Room 011 7
1 Fission Chamber Flatbed Filter Room X7278 1.4 0.1 Fission Chamber Flatbed Filter Room S4626 2
Fission Chamber Flatbed Filter Room X5953 2
Fission Chamber Flatbed Filter Room X2902 3.2 0.2 Fission Chamber Flatbed Filter Room X7277 1
Fission Chamber Flatbed Filter Room K638 2
Fission Chamber Flatbed Filter Room X5954 2
Detector Assembly Flatbed Filter Room D1009 14 1
Fission Chamber Flatbed Filter Room X6453 3.2 0.2 Fission Chamber Flatbed Filter Room Y8427 3.2 0.2 Fission Chamber Flatbed Filter Room W1307 2
Fission Chamber Flatbed Filter Room Z5281 3.2 0.2 Fission Chamber Flatbed Filter Room N1661 2
Fission Chamber Flatbed Filter Room K639 2
Pu-Be Source Cal Facility 160-A-107 14 Pu-Be Source Cal Facility 800-1-32 72 Therefore, the requirements of Section 70.24(a) are not necessary for non-fuel SNM, nor SNM in the form of fuel stored in the new fuel storage racks 4
or spent fuel pool. Granting the requested exemption will not endanger life or property or the common defense and security.
- 3.
Handling Of SNM Special Nuclear Material is handled at the Palisades site by suitably trained and qualified personnel. In addition, persons who may have casual contact with SNM by being in the general vicinity of storage areas must also be trained before being authorized unescorted access to those areas.
Radiation alarm training, at a minimum, is provided in the general employee plant training that each employee receives prior to being badged for unescorted access at Palisades. This training identifies the types of radiation alarms that are used at the plant and the expected employee responses. In addition, employees are trained to consult the applicable radiation work permit for additional instruction prior to starting work.
Irradiated and unirradiated fuel is moved between the new fuel storage racks (unirradiated fuel only), the spent fuel pool, and the reactor vessel for storage and to accommodate refueling operations. New unirradiated fuel is moved into the facility via the spent fuel pool area, and placed either directly into the spent fuel pool, or into the new fuel storage racks located adjacent to the spent fuel pool. The new fuel storage racks are bottomless, which allows water to flow to the next lower level of the Auxiliary Building. It is virtually impossible for the new fuel storage racks to accumulate water such that criticality can occur. The spent fuel pool racks are designed such that even if flooded with non-borated water, criticality can not occur. In all cases, fuel movements are procedurally controlled and designed to preclude conditions involving criticality concerns.
New fuel is received in the fuel receiving area. The fuel assemblies are removed from the shipping container one at a time (two assemblies are shipped in each container) by a single overhead fuel handling crane.
Packing material such as plastic wrapping is removed from the fuel bundle prior to transfer into storage. Upon removal from the shipping container, an assembly is transferred by the crane to either the new fuel storage racks or the spent fuel pool. Only one new fuel assembly can be transferred into or out of a storage location or the reactor at any one time.
Accident analyses have demonstrated that a fuel handling accident (i.e., a dropped fuel assembly) will not create conditions which exceed acceptance criteria. The analyses use the ANSI N16.1 double contingency principle such that two or more extremely unlikely, independent, concurrent events would be required before an inadvertent criticality might be possible. If a fuel assembly were to be dropped in the spent fuel pool, the resulting Ketr would be less than 0.95. In addition, the technical specifications specifically address refueling operations and limit the handling of fuel to ensure against an accidental criticality. The technical specifications also preclude certain load movements over the spent fuel pool and provide requirements for a minimum boron concentration in the spent fuel pool. The boron concentration required by the Palisades Technical Specifications will limit Ketr to less than 0.95 when an assembly is misplaced inside or outside the storage racks.
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. ()..
While movement of nuclear fuel presents a potential opportunity for its loss or diversion, existing procedural controls also ensure SNM handling is authorized and monitored. The absence of an accidental criticality monitoring system does not affect the capability of the Palisades Nuclear Plant to ensure SNM is safeguarded.
Therefore, the requirements of Section 70.24(a) are not necessary for the handling of SNM, and thus, granting this exemption will not endanger life or property or the common defense and security.
C.
The Exemption Requests Are In the Public Interest The guidance provided in Section C.1 of Regulatory Guide 8.12, "Criticality Accident Alarm Systems," Rev. 2 (October 1988) states:
"Section 70.24 of 1 OCFR Part 70 requires alarm coverage in each area in which such licensed special nuclear material is handled, used or stored...,' whereas paragraph 4.2.1 of the standard states that the need for criticality alarms must be evaluated for such areas. If such an evaluation does not determine that a potential for criticality exists, as for example where the quantities or form of special nuclear material make criticality practically impossible or where geometric spacing is used to preclude criticality, such as in some storage spaces for unirradiated nuclear plant fuel, it is appropriate to request an exemption from 70.24." [Emphasis added.]
This language implies that where a licensee determines that design and/or procedural safeguards ensure against conditions of accidental criticality, compliance with Section 70.24(a) would not serve the underlying purpose of the regulation.
As discussed above in Section 11.B, the design of and safety analyses for the spent fuel pool and new fuel storage racks, as well as the associated procedural controls and technical specification requirements, ensure that conditions of accidental criticality are precluded. In addition, the physical security requirements of the plant operating license serve to prevent the loss or diversion of SNM material. Therefore, the application of Section 70.24(a) to the Palisades Nuclear Plant facilities would not serve and is not necessary to achieve the underlying purpose of this requirement.
The continued maintenance of a criticality accident monitoring system would require a considerable expenditure of resources. These expenses would include the operation and maintenance of the system for the life of the Palisades Nuclear Plant, as well as the planning and conducting of drills specifically designed to respond to a criticality accident that has been shown by analysis not to be credible. In light of the purpose of an accidental criticality monitoring system, these expenditures could otherwise be put to better use improving the operation of the Palisades Nuclear Plant. Therefore, the Palisades Nuclear Plant concludes that compliance with Section 70.24 would result in an undue hardship and other costs that are significantly in excess of those likely contemplated when this regulation was adopted.
Exemptions from the requirements of Section 70.24(a) have previously been granted to Part 50 licensees. As an example, an exemption from Section 70.24(a) was granted on October 28, 1996 to the Donald C. Cook Nuclear Plant Units 1 6
and 2 (Dockets 50-315 and 316). We conclude that since the Palisades Nuclear Plant is similar to other facilities granted such an exemption, compliance with
- Section 70.24(a) would create an undue hardship and other costs significantly in excess of those incurred by others similarly situated.
Continued monitoring based on the guidance in 1 OCFR70.24 is unnecessary because of the lack of a credible accident that would produce a criticality. The burden of criticality monitoring for new and spent fuel diverts Palisades Plant resources away from other activities which more directly affect the safe operation of the plant in other areas. Consequently, the exemption request is in the public interest and should be granted pursuant to Section 70.14(a).
111.
CONCLUSION Because an exemption from the requirements of 1 OCFR70.24 for the Palisades Nuclear Plant is authorized by law, will not endanger life or property or the common defense and security, is in the public interest, and is requested for good cause, we respectfully submit that, in accordance with the requirements of 10CFR70.14(a) and 70.24(d), the NRC should grant the requested exemption.
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