ML20099C098

Application for Amend to License NPF-49,revising TS Section 3.3.3.6 for Reactor Vessel Water Level by Incorporating Generic Requirements for Rvlm Sys

ML20099C098
Person / Time
Site:	Millstone
Issue date:	07/27/1992
From:	Opeka J NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20099C100	List: B13747, Proposed Tech Specs Section 3.3.3.6 Re Accident Monitoring instrumentation--reactor Vessel Monitoring ML20099C098
References
B13747, NUDOCS 9208030308
Download: ML20099C098 (6)

Text

NORTHEAST UTILITIES oenew Omce. . seiden street. Bernn. connecticut 3 .NN P O DOX 270 g ' J SIu7 ww[w[o.[. b, HARTF ORD. CONNECTICUT 06141-0270

.mo (203) 665-$000 July 27, 1992 Docket No. 50-421 B13747

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Re: 10CFR50.90 '

U.S. Nuclear Regulatory Commission Attention: Document Contr91 Desk Washington, DC 20555 Gentlemen:

Millstone Nuclear Power Station, Unit No. 3 Proposed Revision to Technical Specifications Accident Monitorina Instrumentation--Reactor Vessel Monitorina Pursuant to 10CFR50.90, Northeast Nuclear Energy Company (NNECO) hereby proposes l to amend Operating License NPF-49 by incorporating the changes identified in Attachment 1 into the technical specifications of Millstone Unit No. 3.

Backaround For Millstone Unit No. 3, the subcaoled margin monitor, core exit thermocouples (CETs), and a reactor vessel coclant inventory tracking system comprise the inadequate core cooling (ICC) instrumentation required by Item II.F.2 M NUREG-0737, the Post-TMI-2 Action Plan. The function of the ICC instrumentation is to enhance the ability of the plant operator to diagnose the approach to, existence of, and recovery from ICC. Additionally, they aid in tracking reactor coolant inventory. These. instruments are included in the Millstone Unit No. 3 technical s

specifications (Section 3.3.3.6).

The heated junction thermocoupla (HJTC) system designed by Combustion Engineering (CE) is used at Millstone Unit No. 3 to monitor coolant inventory in the reactor vessel region above the core. Redundant strings of HJTCs are arranged in the reactor vessel head area to provide indication of conditions at eight distinct level s. The system is a two-channel system, each consisting of a string of eight sensors. The HJTC system is described in the Millstone Unit No. 3 Final Safety Analysis Report Section 4.4.6.5.1, In a letter dated February 19,1985,m the CE Owners Group (CE0G) proposed standard accident monitoring instrumentation (1) R. W. Wells, Chairmn, Combustion Engineering Owners Group, letter to H. L. Thompson, U.S. Nuclear Regulatory Commission, " Technical Specifica-tion for the Reactor Vessel level Monitoring System," dated February -19, 1985.

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U.S, Nuclear Regulatory Commission B13747/Page 2 July 27, 1992 technical specifications for the CE-designed reactor vessel monitorigg system (RVLMS) using an HJTC concept. In a letter dated October 28, 1986,' the NRC concluded that the CE0G proposed technical specificaticas for the RVLMS are acceptable as proposed for application to System 60 and non-System 80 CE-designed  ?

reactors (e.g., Westinghouse reactors). For other reactor designs using the CE HJTC, these technical specifications are als; applicable provided that the channel operability of the HJTC probe is defined- as follows: "A channel is oper2ble if four or more sensors, half or more in the upper head region, and half or more in the upper plenum region, are operable."

Descriotion of Proposed Chanaet The proposed changes will revise Technical Specification Section 3.3.3.6 for reactor vessel water level by incorporating gengric) requirements for the RVLMS proposed by the CEOG and accepted by the NRC. Specifically, the proposed changes will accomplish the following:

. Provides in Section 3.3.3.6 separate actions when either one or two channels of reactor vessel water level monitoring are not operable.

. Adds a definition to Table 3.3-10 of an operable channel.

Clarifies Table 4.3-7 that an electronic calibration from the ICC cabinets is the appropriate surveillance for the reactor vessel water level instrumentation.

. Revises the Bases in support of these changes.

Currently, inoperability of one or both channels of reactor vessel level instrumentation would require a shutdown if operability is not restored within a specified time frame. The changes proposed-herein provide flexibility to use alternate methods of monitoring reactor vessel level, thereby precluding an unnecessary plant shutdown. The- CETs will be used as an alternate means of monito'-ing the reactor vessel inventory.

Technical Specification Section 3.3.3.6 is being revised to provide new separate actions (i.e., ACTIONS 'e' and 'f') to be taken when either one or both channels of reactor vessel water level monitoring are declared inoperable. With the number of operable channels for the reactor vessel water level monitor less than the total number of channels shown in Table 3.3-10, actions include restoring the (2) D. M. Crutchfield letter to R. W. Wells, " Safety Evaluation of Generic Technical Specification Proposed-by Conustion Engineering Owners' Group for the Reactor Vessel Level Monitoring System," dated October 28, 1986.

(3) D. M. Crutchfield letter to R. W. Wells, " Safety Evaluation of Generic Technical Specification Proposed by Combustion Engineering Owners' Group for the Reactor Vessel Level Monitoring System," dated October 28, 1986.

U.S. Nuclear Regulatory Commission i B13747/Page 3 July 27, 1992 inoperable channel to operable status within 7 days if repairs are feasible without shutting down or preparing and submitting a special report to the Commission within 30 days following the event outlining the action taken, the cause of the inoper:bility, and the plans and schedule for restoring the channel to operable status. With the number of operable channels for the reactor vessel water level monitor less than the minimum channels operable requirement of Table 3.3-10, actions include restoring the inoperable channel (s) to operable

status within 48 'm irs if repairs are feasible without shutting down or initiating an alteinate method of monitoring the reactor vessel inventory, preparing and submitting a special report to the Commission within 30 days following the event, and restoring the inoperable channel (s) to operable status at the next scheduled refueling. In addition, ACTIONS 'a' and 'b' of Technical Specification 3.3.3.6 are clarified to reflect the new ACTIONS 'e' and 'f'. Due to the addition of two new ACTION statements, existing ACTION 'e' now becomes ACTION 'g'.

For purposes of clarification, a definition of an operable reactor vessel water

. level channel is being added to Table 3.3-10 which defines a channel as operable if four or more sensors, half or more in the upper head region and half or more in the upper plenum region, are operable. This definition is consistent with that proposed by the CE0G and accepted by the NRC.

4 A footnote is being added to Table 4.3-7 that indicates that the surveillance required for the reactor vessel water level accident monitoring instrumentation is by means of electronic calibration from the ICC cabinets only. This is required since authentic simulation of the reactor vessel coolant level monitoring system cannot be conducted due to their physical location and range.

This proposed change was identified in NNEC0'y) response to Generic letter 83-37,

" Proposed Technical Specification Changes,"( and was accepted di the NRC.

Additional changes are being made to the Bases in support of the changes identified above.

Safety Assessment All design basis accidents were reviewed for any potential impact due to these changes. Since these monitors provide no control functions, none of the proposed changes would adversely impact the consequences of any postulated accident.

These changes provide flexibility to utilize an alternate method of monitoring the reactor vessel level inventory if the operable channel (s) cannot be restored in 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. In addition, these changes are consistent with that proposed by the CE0G and accepted by the NRC.

(4) E. J. Mroczka letter to the U.S. Nuclear Regulatory Commission, " Millstone Unit No. 2, Proposed Changes to Technical Specifications Generic letter 83-37--NUREG 0737," dated July 21, 1987.  ;

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U.S. Nuclear Regulatory Commission B13747/Page 4 July 27, 1992 Sianificant Hazards Consideration i

NNECO has reviewed the proposed changes in accordance with 10CFR50.92 and has ccncluded that the changes do not involve a significant hazards consideration.

, 1he basis for this conclusion is that the three criteria of 10CIR50.92(c) are not compromised. The proposed changes do not involve a significant hazards consideration because the changes would not:

1. Invr le a significant increase in the probability or consequences of an ace . ant previously analyzed. The proposed changes will reviss +.he sur-vetilance and operabilitu requirements of the reador vessel water level monitoring instrumentativ. by incorporating generic requirements ptoposed by the CEOG and accepted by the NRC Staff. These t.hanges provide flext-bility to utilize an alternate method of monitoring the reacter vessel inventory if the inoperable channel (s) cannot be resto.ed to operable status within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, thereby precluding an unnecessary plant shutdown.

The changes also allow for the restoration of the inoperable channel (s) to be accomplished during the next scheduled refuei.1 The proposed changes are bounded by the dewjn basis analysis and will have no negative impact on the probability of occurrence of any design basis ace! dent.

2. Crea'a the possibility of a new or different kind of accident from any previously analyzed. There are no physical design changes associated with the proposed technical specification changes. Therefore, there can be no impact on plant response to the point where a different acc' dent is created.

3. Involve a significant reduction in a margin of safety. Since the proposed changes to Technical Spet.ification 3.3.3.6, Table 3.310, and Table 4.3-7 do not affect the consequences of any accident previously analyzed or on any of the protective boundaries, there is no reduction in the margin of safety, in summary, I he reasons identified above, NNECO has concluded that continued operation of t facility in accordance with the proposed amendment would not involve a significant hazards con % ration.

Moreover, the Commission has provided guidance concerning the application of standards in 100FR50.92 by providing certain examples (March 6,1986, SlFR7751) of amendments that are considered not likely to involve a significant hazards consideration. Although the proposed changes are not envelopeo by a specific example, the proposed changes would not involve a significant increase in the probability or consequences of an accident previously analyzed. The changes to Section 3.3.3 A separate the actions to be taken with either one or both channels

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of RVLMS inopa.ible. The changes to Table 3.3-10 add a definition of an operable reactor vessel level water level channel, and the changes to Table 4.3-7 clarify the typn of surveillance for the reactor vessel water level accident monitoring instrumentatio . These proposed changes are consistent with those proposed by the CEOG and accepted by the NRC Staff.

U.S. Nuclear Regulatory Consnission B13747/Page 5 July 27, 1992 NNECO 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 off-site, nor significantly increase individual or 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 categorictil exclusion from the requirements for an environmental impact statement.

The Millstone Unit No. 3 Nuclear Review Board has revleued and approved the proposed changes and has concurred with the above determination.

The attached retype of the proposed changes to the technical specifications reflects the currently issued version of the technical specifications. Pending 4

technical specification changes or technical specification changes issued subsequent to this submittal are not reflected in the enclosed retype. The enclosed retype should be checked for continuity with technical specifications prior to issuance. Revision bars are provided in +.he right hand margin to

indicate a revision to the text.

Regarding our schedule for this amendment, we request issuance at your earliest convenience with the amendment effective within 30 days of issuance, in accordance with 10CfR50.91(b), we are providing the State of Connecticut with a copy of this proposed amendment.

Should you have any questions, please contact my staff.

Very truly yours,

NORTHEAST NUCLEAR ENERGY COMPANY l

FOR: J. F. Opeka Executive Vice President BY: Y W. D. RombergVice President (/

cc: Mr. Kevin McCarthy, Director Radiation Control Unit

Department of Environmental Protection j Hartford, CT 06106 l

l T. T. Martin, Region 1 Administrator l V. L. Rooney, NRC Project Manager, Millstone Unit No. 3 i

P. D. Swetland, Senior Resident inspector, Millstone Unit Nos. 1, 2, .

and 3

U.S. Nuclear Regulatory Comission B13747/Page 6 July 27, 1992 STATE OF CONNECTICUT f ,n -

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COUNTY OF HARTFORD

Then personally appeared before me, W. O. Romberg, who being duly sworn, did

! state that he is Vice President of Northeast Nuclear Energy Company, a Licensee i herein, that he is authorized to execute and file the foregoing information in i the name and on behalf of the Licensee herein, and that the statements contained in said information are true and correct to the best of his knowledge and belief.

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