ML20249A790
| ML20249A790 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 06/17/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20249A785 | List: |
| References | |
| NUDOCS 9806180241 | |
| Download: ML20249A790 (5) | |
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UNITED STATES s
E NUCLEAR REGULATORY COMMISSION o
WASHINGTON. D.C. 20555 4001
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- s * *,o SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.149 TO FACILITY OPERATING (POSSESSION ONLY)
LICENSE NO. DPR-3 YANKEE ATOMIC ELECTRIC COMPANY YANKEE NUCLEAR POWER STATION (HOWE)
DOCKET NO. 50-29
1.0 INTRODUCTION
By le ter dated September 5,1997, and as supplemented by a letter of March 30,1998, the Vankee Atomic Electric Company (YAEC or the licensee), submitted a license amei dment request to change the facility Defueled Technical Specifications (DTS) for the Yankee Nuclear Power Station (YNPS). The requested changes would enable the licensee to bring an 80-ton gross weight shipping and/or transfer cask into the Spent Fuel Pool Storage Building. Also submitted as part of the justification for these modifications is the YAEC proposal to upgrade the YNPS cask handling crane (a yard area crane) to single-failure-proof design. The proposed changes to the DTS and the crane upgrade are needed to enable any future movement of spent fuel and Greater-Than-Class C (GTCC) waste in shipping / transfer casks from the spent fuel pit (SFP) to either temporary onsite dry storage or permanent offsite storage. The letter of March 30,1998, provided clarifying information and did not change the proposed no significant hazards consideration determation.
2.0 BACKGROUND
NUREG-0612, " Control of Heavy Loads at Nuclear Power Plants" provides guidelines and recommendations to licensees to ensure safe handling of heavy loads over spent fuel pools and spent fuel assemblies by prohibiting load travel os er spent fuel assemblies to the extent practicable, over the core for an operating reactor, and over safety-related equipment.
The requirements of both the proposed DTS and adrninistrative control procedures would implement the guidelines recommended by NUREG-0612. DTS 3.1.2 requires a minimum of five feet of water be maintained over the top of spent fuel assemblies stored in casks within the SFP. As stated by the licensee, five feet of water reduces the potential occupational exposure to individuals to "as low as reasonably achievable" (ALARA).
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l Existing DTS 3.2 and plant procedures currently prohibit the travel of heavy loads (loads l
greater than 900 pounds) over spent fuel assemblies in the SFP. However, DTS 3.2 and 4.2.1.a also identified specific heavy loads including shipping casks (35-ton maximum gross weight), cask components and associated lifting devices, the spent fuel inspection stand, fuel handling equipment, spent fuel racks, shipping cask liners, volume reduction equipment, and the Spent Fuel Storage Building roof hatches, etc., that are excepted from these requirements and, therefore, are currently allowed to be moved over fuct assemblies in the SFP.
The existing DTS 4.2.1.b specifies that certain loads including the fuel inspection stand, the temporary gate, the shielding panels, the spent fuel assembly nondestructive equipment, and cask hatch covers will be prevented from travel over spent fuel in the SFP by administrative control. Other components, such as the volume reduction equipment, shipping cask liners, and shipping casks, etc., wil1 be prevented from travel over spent fuel assemblies in the SFP by administrative control coupled with a steel frame (bumper) at the edge of the SFP. DTS 4.2.1.c specifies that the fuel handling equipment will also be prevented from travet over spent fuel assemblies in the SFP by administrative control when j
it is moved for maintenance.
To enable movement of spent fuel out of the SFP into storage, the licensee is proposing to modify the existing DTS 3.2 by adding an 80 ton cask as an allowed load in the SFP Building. The licensee is also proposing to eliminate the requirement for a minimum of five feet of water to cover the top of irradiated fuel assemblies during transport of the fuel l
assemblies within shipping and/or transfer casks. This requirement was originahy used to ensure that the exposure to personnelin the SFP area, during fuel movements, would be maintained ALARA. The licensee states that the shielding design of the proposed cask by itself provides the additional radiation protection needed to limit the exposure to personnel in the SFP area to ALARA limits The licensee also proposes to upgrade the crane to single-failure-proof design with ar. 80-ton capacity in order to handle the larger, heavier casks.
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3.0 EVALUATION 3.1 DTS 3.1.3 and Bases 3/4.1-Spent Fuel Pit Water Level I
l The existing DTS 3.1.1 requirement that a minimum of 14 feet of water be maintained over j
the top of irradiated fuel assemblies while they are in the storage racks remains unchanged.
Likewise, the DTS 3.1.2 requirement that a minimum of five feet of water be maintained l
over the top of irradiated fuel assemblies while they are out of the storage racks, but still in the SFP and not yet stored in casks, remains unchanged. Both requirements help ensure that the shielding 6:e to pool water is available in o'rder to protect personnel in the SFP l
area from potentially high occupational radiation exposure. The existing DTS Bases 3/4.1 pertains to irradiated fuel not seated in the storage racks and involves routine fuel i
movements for fuel not stored in spent fuel shipping and/or transfer casks.
The proposed addition of DTS 3.1.3 and the revision to DTS Bases 3/4.1 state that, while irradiated fuel is being transported in and out of the SFP in shipping and/or transfer casks, a l
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minimum of five feet of water over the top of the irradiated fuel assemblies in the casks is not needed. The licensee by letter dated March 30,1998, stated that it is their intent to utilize a shipping and/or transfer cask that has been previously approved by NRC in accordance with 10 CFR Part 71 and/or 10 CFR Part 72 and the design of the cask must meet the regulatory dose rate limits. The licensee will develop and implement procedures and administrative controls that limit personnel exposure to the radiation protection limits specified in 10 CFR Part 20. The cask design coupled with control measures taken by the licensee would maintain the radiation protection to individuals to ALARA. Based on the above, the staff finds these proposed changes to the DTS are acceptable.
i 3.2 Proposed Changes to DTS 3.2,4.2.1.a, 4.2.1.b, and Bases 3/4.2 - Crane Travel -
Spent Fuel Pit The proposed changes to DTS 3.2 and Bases 3/4.2, " Crane Travel - Spent Fuel Pit," would delete components such as the temporary gate, and shielding panels from the list of components allowed over spent fuel assemblies in the SFP. It also adds the new spent fuel
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storage casks (maximum gross weight limit of 80 tons), cask components and associated lifting devices, and the cask set-down pad to the list of components that can travel over the SFP. The DTS limit travel over fuel assemblies by administrative control and through the crane travel limit switches.
The proposed changes would also allow for safe handling of casks, cask components and j
associated lifting devices, and the cask set-down pad over the SFP area. These changes to i
the DTS enablo the licensee to move the new spent fuel casks out of the SFP area in accordance with NUREG-0612. The changes identify specific heavy loads that are allowed to be handled near the fuelin the SFP. As stated by the licensee, procedures will be developed and used to control the handling of these loads over the SFP.
The licensee changed DTS 4.2.1.a to permit, in addition to the existing components, the new shipping and/or transfer casks, cask components and associated lifting devices to travel over the SFP only in accordance with approved written procedures.
The licensee also proposed changes to DTS 4.2.1.b so that the restriction on load travel over spent fuel assemblies by the volume reduction equipment (when moved by the Yard Area Crane), the spent fuel inspectica stand, and the spent fuel assembly nondestructive equipment would be implemented through administrative control procedures. The travel restriction defined as a safe load path for these components would be enforced by both administrative control procedures and a crane travellimit switch. The limit switch prevents crane travel beyond the end of the safe load path, thus providing defense in depth. The cask hatch cover, cask components, and associated lifting devices are allowed over spent fuel assemblies only when assembled with the shipping / transfer casks during cask operations and only in accordance with the appropriate procedures.
The prcposed changes to the DTS are consistent with and are in accordance with the guidelines of NUREG-0612, Section 5.1.1(2). The NUREG recommends that procedures be developed to cover load handling operations for heavy loads that are or could be handled 1
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4 over or in the proximity of the SFP and irradiated fuel. The licensee states that in addition to the revised DTS, administrative control procedures specific to the movement of particular heavy loads will be implemented. The load path limit switch provides additional protection. The proposed change to Bases 3/4.2 properly justifies the use of the single-f failure-proof crane and is consistent with the NUREG-0612 guidance. Based on these considerations, the staff finds these changes to be acceptable.
3.3 Upgrade of Cask Handling Crane NUREG-0612, " Control of Heavy Loads at Nuclear Power Plants," provides recommendations to ensure safe handling and control of heavy loads. YAEC proposes to upgrade its crane in accordance with these by acquiring an Ederer Extra Safety and Monitoring (X-SAM) crane designed to the single-failure-proof requirements of NUREG-0554. The crane has a design capacity of 80 tons for the main haist and has the capability needad to lift the new casks. In the event of a malfunction, the single-failure proof capaoility of the crane enables the licensee to hold the load in place or move the load to a secure location and set it down until the adverse condition is resolved.
Other crane modifications include improved instruments and controls; replacement of the existing bridge and trolley, main and auxiliary hoist motors, and brakes and controls. As noted, the crane will be equipped with a crane travellimit switch to prevent the movement of the crane beyond the designated safe load path. Therefore, both the enhanced crane design and the procedural controls will serve to reduce the potential for a heavy load drop on irradiated fuelin the SFP to an acceptable level. Based on the above, the staff finds the proposed crane modifications to be acceptable.
The major causes of load handling accidents involve operator errors, rigging failures, lack of adequate inspection, and inadequate procedures. The licensee willinstitute the following actions to eliminate accidents: (1) the use of appropriate administrative controls and procedures to govern the operation of the crane during the transport of heavy loads; (2) the establishment and maintenance of a safe load path; (3) inspections, maintenance and testing of the crane to appropriate ANSI standards; and (4) training, qualification and instruction of crane operators in accordance with the appropriate ANSI standards in regard to crane operation, rigging and handling of lifting devices. The staff concludes that these measures will significantly enhance the safety of cask handling and other lifts near or over spent fuel.
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4.0 CONCLUSION
S ON MODIFICATIONS Based on the above discussions, the staff finds that the changes to the DTS, the administrative procedures to improve the handling and control of heavy loads including l
j spent fuel shipping / transfer casks and the upgrade to a single-failure-proof crane are in accordance with the guidelines of NUREG-0612 and NUREG-0554. These changes properly enable the licensee to handle the proposed 80-ton casks over the SFP and the transport of the cask components and associated lifting devices and other components pertinent to spent fuel operations over spent fuel assemblies during cask operations. The l
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licensee has committed to design the lifting devices to single failure proof standards or to increase the margin of safety of the lifting devices as specified in NUREG-0612. Based on L
' the above, the staff concludes that the new crane and the upgraded lifting devices, the crane test program _ and crane operator training and qualification program reduce the probability of a load drop over spent fuel in the SFP to an acceptable level. Therefore, the j
' proposed changes to the DTS are acceptable.
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5.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Commonwealth of Massach'usetts state liaison official was notified of the proposed issuance of the amendment. The State l
official had no comments.
6.0. ENVIRONMENTAL CONSIDERATION l
The amendment changes requirements with respect to installation or use of facility l
components located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendment involves no significant increase in the amounts; and no significant change in the types, of any effluents that may be released offsite, and l
that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment
' involves no significant hazards consideration, and there has been no public comment on
'such finding (62 FR 54879). Accordingly, the amendment meets the eligibility criteria for l
categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no i'
. environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
7.0 CONCLUSION
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. The Commission has concluded, based on the considerations discussed above, that: (1)'
there is reasona'ble assurance that the health and safety of the public will not be L
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 L
. not be inimical to the common defense and security or to the health and safety of the
- public.
Principal Contributor: Brian E. Thomas Dated:. June 17, 1998 p
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