ML20128B321
| ML20128B321 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 01/26/1993 |
| From: | Opeka J NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20128B325 | List: |
| References | |
| B14256, NUDOCS 9302030005 | |
| Download: ML20128B321 (5) | |
Text
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, NORTHEAST UTILITIES cene,ei On.ce,. semen street. sernn, connecucut 1
Ui SU.ItScN P.O. BOX 270
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HARTFORD CONNECTICUT 06141-0270 J
. *w.mw io,, w (203) 665-5000 January 26, 1993 Docket No. 50-423 Bl.4251 Re:
10CFR50.90 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Gentlemen:
Millstone Nuclear Power Station, Unit No. 3 Pronosed Revision to Technical Specifications Electrical Power' System _s: AC. DC. Onsite Power Distribution--3hutdown Pursuant to 10CFR50.90, Northeast Nuclear Energy Company (NNECO) hereby proposes to amend its Operating License, NPF-49, by incorporating the changes identified in Attachment 1 into the Technical Specifications of Hillstone Unit No. 3.
Description of Proposed Chanae This proposed change will revise Technical Specification Sections 3.8.1.2, 3.8.2.2, and 3.8.3.2.
These technical specifications govern electric power systems; AC sources, DC sources, and onsite power distribution for shutdown conditions (modes 5 and 6).
Each change is delineated below:
I)
Section 3.8.1.2 Section 3.8.2.2 Section 3.8.3.2 A requirement is being added to the Action Statements to suspend any operations with a potential for draining the reactor vessel.
With less than minimum required power sources available, these actions are warranted to prevent inadvertent uncovering of fuel assemblies.
11)
Section 3.8.2.2 Sect'.on 3.8.3.?
A requireme' being added to the Action Statements to suspend crane operations witn loads over the fuel storage pool.
(This requirement is already included in Section 3.8.1.2.)
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U.S. Nuclear Regulatory Commission B14256/Page 2 January 26, 1993 With less than minimum required power sources available, these actions are warranted to protect against the possible occurrence of an accident condition which could damage irradiated fuel assemblies.
III) Section 3.8.1.2 Section 3.8.2.2 Section 3.8.3.2 The requirement for depressurizing and venting the reactor coolant system is being deleted from these sections.
This requirement is already covered by Technical Specification 3.4.9.3, Overpressure Protection System.
Ther fore, this requirement is being delettd from these three sections to eliminate redundant requirements.
IV)
Section 3.8.1.2 The requirement to restore the required AC power as soon as possible is being expanded to include all of modes 5 and 6.
The present requirement is to restore the required AC power as soon as possible with low water-N leirel in mode 6 or with the reactor coolant system loops not filled in mode 5.
hf.ety Assessment The proposed changes have been determined to be safe.
These changes are applicable to modes 5 and 6.
The accidents analyzed for modes 5 and 6 are:
fuel handling accident, baron dilution, core misload, and cask drop.
Placing additional restrictions on operations with a potential for draining the reactor vessel and on crane operation with loads over the fuel storage pool do not affect the accident analyses.
The proposal to delete the requirement to depressurize the reactor coolant system (RCS) and vent through a 5.4 square-inch opening from these technical specifications was analyzed. The proposed change to eliminate the requirement to depressurize and vent the RCS does not create the possibility of a different accident since the function the vent provided, overpressure protection, is being fulfilled by Technical Specification 3.4.9.3.
Thus, the need to depressurize and vent is captured and bounded by en existing technical specification.
The bases for the requirement to depressurize and vent the RCS upon loss of AC or DC power or the associated buses while shutdown was to ensure that the reactor vessel cannot be overpressurized.
Technical Specification 3.4.9.3 ensures overpressure protection by requiring at least one of three systems to be operable to provide everpressure protection. This can be two residual heat removal (RHR) suction relief valves, two power operated relief valves (PORVs),
or a vent area of 5.4 square inches.
Technical Specification 3.4.9.3 is
e U.S. Nuclear Regulatory Commission B14256/Page3 January 26, 1993 applicable in modes 3, 4, 5, and 6.
Therefore, the requirement to provide overpressure protection during shutdown in the technical specifications for electrical distribution is not necessary as these requiremants are bounded and captured by Technical. Specification 3.4.9.3.
Sianificant Hazards Consideration HNECO has reviewed the proposed changes in accordance with'10CFR50.92 and-has concluded that the changes do not involve a significant' hazards consideration.-
The basis for this conclusion is that the three criteria of 10CFR50.92(c) are nct compromised.
The proposed changes do not. involve a significant hazards consideration brecause the changes would 'not:
1.
Iavolve a significant increase in the probability or consequences of an accident previously analyzed.
Three of the-proposed changes add additional restrictions to the technical specifications while.one change removes an unnecessary restriction which is adequately. covered by -
Technical Specification 3.4.9.3, Overpressure Protection.
The proposed changes do not affect any of the design basis accidents nor are there any malfunctions associated with these changes.
2.
Create the possibility of a new or different kind of accident from any-previously analyzed accident.
The proposed change _to eliminate the requirement to depressurize and vent the RCS does not create-the-possibility of a. different accident since the function that the vent provided, overpressure protection, is being fulfilled by Technical Specification 3.4.9.3.
Thus, as-long as this overpressure protection is in place there is no possibility of'an accident of a different type than previously evaluated.
3.
Involve a significant reduction in the margin of safety.
The bases for the requirement to depressurize and vent the RCS upon a loss of AC or DC power or the associated buses while shutdown was to ensure that the -
reactor vessel cannot be overpressurized.
Technical-Specification 3.4.9.3. requires ona of' three systems be operable to provide overpress9re protection. This can be two RHR suction relief valves, two PORVs, or a vent area of S.4 square inches.- Since one of these systems must be operable by Technical Specification 3.4.9.3, it is not necessary-to have another technical specification require the vent.
Only the PORVs require electrical power (battery) to function.
By procedure, the PORV must be declared _ inoperable when its associated battery is inoperable.
Thus, Technical Specification 3.4'.9.3 adec;uately ensures that the RCS presaire bpundary is protected.
As a result, the proposed-change does not impact the margin of safety.
In summary, for the reasons identified above, NNECO 'has concluded that~
continued operation of the facility in accordance with the proposed amendment would not involve a significant hazards consideration,
U.S. Nuclear Regulatory Commission B14256/Page 4 January 26, 1993 Moreover, the Commission has provided guidance concerning the application of standards in 10CFR50.92 by providing certain examples (March 6,
- 1986, SlFR7751) of amendments that are considered not likely to involve a
significant hazards consideration.
The requirement to suspend any operations with a potential for draining the reactor vessel, to suspend crane operations with loads over the fuel storage pool, and to restore required AC power as soon as possible to include all of modes 5 and 6 constitute additional limitations, restrictions, or controls not presently in the technical specifications and therefore, fall within the scope of example (ii) of examples of amendments that are considered not likely to involve significant hazards provided in 51FR7751.
The changes to Sections 3.8.1.2, 3.8.2.2, and 3.8.3.2 include adding a requirement to the Action Statements to suspend any operations with a potential for draining the reactor vessel.
The requirement for depressurizing and venting the reactor coolant system is being deleted from these sections.
Also, a requirement is being added to the Action Statements of Sections 3.8.2.2 and 3.8.3.2 to suspend crane operations with loads over the fuel storage pool.
(This requirement is already included in Section 3.8.1.2.)
Finally, the requirement in Section 3.8.1.2 to restore the required AC power as soon as possible is being expanded to include all of modes 5 and 6.
The present requirement is to restore the required AC power as soon as possible with low water level in mode 6 or with the RCS loops not filled in mode 5.
NNEC0 has reviewed the proposed license amendment against the criteria of 10CFR51.22 for environmental considerations.
The proposed changes do not involve a significant hazards consideration, nor increase the types and amounts of effluents that may be released offsite, nor significantly increase individual ur cumulative occupational radiation exposures.
Based on the foregoing, NNECO concludes that the proposed changes meet the criteria delineated in 10CFR51.22(c)(9) for a
categorical exclusion from the requirements of an environmental impact statement.
The Millstone Unit No. 3 Nuclear Review Board has reviewed and approved the proposed changes and has concurred with the above determination.
In accordance with 10CFR50.91(b), we are providing the State of Connecticut with a copy of the proposed amendment.
Regarding our proposed schedule for this amendment, we request issuance at your earliest convenience with the amendment effective as of the date of issuance, to be impicmented within 30 days of issuance.
I
U.S. Nuclear Regulatory Comission B14256/Page 5 January 26, 1993 Should you have any questions, please contact my staff.
Very truly yours, NORTHEAST NUCl. EAR ENERGY COMPANY AFCut g
v J. F.(_0p#ka Executive Vice President cc:
T. T. Martin, Region I Administrator V. L. Rooney, NRC Project Manager, Millstone Unit No. 3 P. D. Swetland, Senior Resident inspector, Millstone Unit Nos.1, 2, and 3 Mr. Kevin McCarthy Director, Radiation Control Unit Department of Environmental Protection Hartford, CT 06116 Subscribed and sworn to before me this & day o n umg /. 1993 Wz e a:..
b W/ M N e
~
otary Public~
Date Commi sion Expires:
3/ 9j3
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