ML20009D045

Forwards Addl Justification & Safety Analyses for License Amend Requests in Response to NRC 810529 ltr.Torus-related Changes,Containment Purge & Plant Operations Review Committee Changes Discussed

ML20009D045
Person / Time
Site:	Browns Ferry
Issue date:	07/13/1981
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:	Harold Denton Office of Nuclear Reactor Regulation
References
NUDOCS 8107230013
Download: ML20009D045 (6)

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@ f TENNESSEE. VALLEY AUTHORITY CHATTANOOGA.- TENNESSEC 374ol 400 Chestnut Street Tower II

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July 13, 1981

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Mr..Harc1d R'. Denton, Director k

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Dear Mr. Denton:

In the Matter of the

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Docket Nos. 50-259 Tennessee Valley Authority

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50-269 50-296 3

T. A. Ippolito's letter to H. G. Parris dated May 29, 1981-requested that we provide additional justification and safety analyses for license amendment requests TVA BFNP TS 161, TS 162, and TS 163 The additional justification'and safety analysis for TS 161 is provided as Enclosure 1.

A description of changes, justification, an'J safety analysis for TS 163 are contained in Enclosure 2.

The requested information for TS 162 will be submitted separately at a later date.

Very truly yours, a

TENNESSEE VALLEY AUTHORITY (L. N.' Mills, Manager Nuclear Regulation and Safety

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ENCLOSURE 1 SUPPLEMENTAL-INFORMATION FOR LICENSE AMENDMENT REQUEST TVA BFNP TS 161 J

BROWNS FERRY NUCLEAR PLANT UNIT 1-(DOCKET NO. 50-259)

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TORUS RELATED CHANGES-Numerous modifications are being implemented in the unit 1 torus during the current unit 1 refuel outage as part of the Mark I Containment Program. These modifications were determined as necessary by TVA to restore the originally intended margins of

. safety,in the containment design.. The following is a general L

' discussion of why the changes to the technical specifications are proposed. The details of the modifications design will be provided in the Browns Ferry Plant Unique Analysis (PUA), scheduled for submittal in early 1982. By letter from T. A. Ippolito to H. G.

Parris dated January 13, 1981 TVA received the license orders for torus modification. The order states that the plant-unique analyses should be submitted for confirmatory review by the staff. From that letter and other staff discussions it is our understanding that the PUA is to be given a post-implementation audit by the NRC staff.

DESCRIPTION AND JUSTIFICATION OF CHANGES Page 227 - Cnange in torus water level limits from "-7 inches ( A P O =

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psid)" and "-8 (dP = 0 psid)" to "-6.25 inches (AP O = psid)" and "-7.25 inches (AP = 0 psid)", respectively. There are 15-inch by 15-inch sealed box beams being added as support for the safety relief valve lines, and

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'HPCI-RCIC internal supports. Addition of these supports will result in appreciable water displacement. Calculations indicate that the box beams and HPCI-RCIC supports will increase the torus water level approximately 3A inch due to their presence. This rise in the torus water level is reflected in these revised technical specification values.

P ga 2357'-Changa in the satpoint for thn dryws11-wstw311 differsntial

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pressure control (d P) from 1.3 paid to 1.1 psid. Downcomer water

_ clearing loads are greatly reduced by physically shortening the downcomers ani imposing a drywell-wetwell AP. The Browns Ferry unique loads were determined by.considering a differential pressure of 1.10 psid at the maximum allowable torus water level.

In order to be consistent with thid analysis'the technical specification associated with the AP control has been. established at 1.10 psid.

Page 267 -Revisions to the bases to reflect shortening of the downcomers

~by approximately one foot, different values of water volume (at maxieum water level), and new values for minimum water level 1,.

cation.

Page 268 -Change'of the peak temperature of the torus water from 160 F to

.200 F local. During the current unit 1 refuel outage the T-quenchers are being added - to the safety-relief valve discharge device. The NRC licensed value for the T-quencher is 200 F local water temperature (to f

avoid excessive' steam condensing loads). This technical specification

. change is needed to reflect that T-quencher licensed value of

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Page'269 -Change to the bases of the values for the d P control from 1.3 to 1.1 psid and the value for the range 'of downcomer submergence from "4.0 feet to 4.60. feet" to "3 06 feet to 3 58 feet." This change is

needed to' reflect the planned modifications of downcomer shortening and

' revised differential pressure control setpoint.

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SAFETY ANALYSIS

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As mentioned earlier the detailed safety analysis for the torus m'5difications (Browns Ferry Plant Unique Analysis) wi11 be submitted later' for confirmatory review by the NRC staff.

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Bl CONTAINMENT PURGE i

During the current unit'1 refueling outage we are modifying the d

' containment. purge system to satisfy applicable requirements of NRC Branch Technical Position CSB 6-4 regarding valve closure times and debris screens. These modifications were designed in response to NRC letters from D. G. Eisenhut to All Light Wate Reactors dated September 27, 1979, and from-T. A. Ippolito to H. G. Parris dated October 22,:1979.

Pages 251 and 252 - Decrease of Valve Closure Times -TVA has performed a safety evaluation on the. modifications and has concluded that the changes are a safety improvement. The faster valve closure times reduce analytic offsite dose and the debris screens provide further protection against

' foreign material entering the purge ducting and interfering with closure of!the purge valves.

As operability analysis of the containment' purge valves was submitted to NRC by letter from L. M. Mills to T. A. Ippolito dated June 2, 1981.

That analysis shows that the purge valves are adequate for closure

.against design basis Loss-of-Coolant accident forces.

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,FURTHER' JUSTIFICATION FOR TVA BFNP TS 161 Pages-30 and 219 -Change of safety relier. valve total relief capacity

from.82.6' percent toI83.9 percent.-

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Explanation of Change

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' The value of 83 9 percent total rell'er-capacity is derived from the =

valuesiof 77.46 percent for 12 -SRV's operable out of a total of 13 SRV's.

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The capacity of-77.46 percent of nuclear boiler rated -steam. flow, as 211sted in the BF 1' Reload 4 Supplementa'1 Reload. Licensing submittal, was

' calculated based on certified valve capacity for a'5.125-inch throat diameter valve (869,000 lbs/ hour at-1,090 + 3 psig) issued by the ASMS National' Board of Boiler and Pressure Vessel Inspectors.. The certified

-values are obtained by testing and are listed as 90 percent of the

- measured capacity values' for conservatism.'-

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_Pages ' 122. 123, 124, an'd' 129 Rod Sequence Control System (RSCS) Requirement Changes In order to obtain-additional' physics data special cold criticality tests haye been. planned for this cycle. These criticality tests require suspension of RSCS constraints by means of.the individual rod bypass switches.'- This testing is planned as part of the Lead Test Aseembly

. program which TVA is participating with GE in.-

An analysis was performed-to show that a' postulated rod drop accident involving control: rods withdrawn during the cold critical test would not-exceed the l peak fuel e'nthalpy ' design limit of. 280 cal /gm. The rod worth

- minimizer?.(RWM)'will;be programmed to. ensure adherence to the withdrawal sequence specified in the cold' critical test procedure. The RWM must be

- operable for this test.

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These changes are' administrative changes that remove references to

-nonapp'11 cable.techaica'l specification requirements. These changes do not affect any actual imiting conditions for operation; therefore, plant safety'is.not affected.

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'Page 158 -Reformatting'of the information shown on the page. The portion of information 'in ~ sections 3.5.H and 4.5.H shown on page 159 was moved to page 158 without changing any of the information.

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ENCLOSURE 2 gf > -

SUPhoEMENTAL INFORMATION FOR LICENSE AMENDMENT' REQUEST TVA BFNP TS 163 BROWNS FERRY NUCLEAR PLANT.

(Df,CKET NOS. 50-259, -260, -296) i Description of Chr.nge JUnits 1 and 2 - page 332-Unit 3.- page 362-

'This change deletes a reference to the-fire restoration coordinator,

=section 6.9 Reason / Justification for Change Section 6.9,~ Overall Restoration Coordinator has been deleted from the

Browns. Ferry Technical Specificationa by Amendments 71, 68, and 43 to

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licenses DPR-33, -52, and -68 (T. A. Ippolito's letter to H. G. Parris

~-dated June 18, 1981).

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~ Description of Change Units 1 and 2 - pages 332, 346

' Unit: 3.- pages 362, 376

Changes title of responsible individual from " Chief, Nuclear Generation Branch". to " Assistant Director of Nuclear Power (Operations)."

i Units 1_and 2 - page 337

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Unit 3 - page 367.

Changes. titles of responsible' individuals from " Director, Power

-Production" and " Chief, Nuclear Generation Branch" to " Director of Nuclear Power" and " Assistant Diretor of Nuclear Power (Operations)."

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Reason / Justification for change

.These changes reflect organizational changes which resulted from the separation of TVA's Division of Power Production into the Division of

- Nuclear Power and the Division of Fossil and Hydro Power.

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a Description of Change Units 1 and 2 - page 335 Unit 3.- page 305.

These changes revise'th's membership of the Plant Operations Review t;,_

Committee. They specify that section supervisors (i.e., electrical maintenance section supervisor, mechanical maintenance section supervisor, etc) comprise the PORC. Also, these changes allow the plant superintendent's' representative to chair the meeting rather than

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specifying an assistant plant'auperintendent.

Reason / Justification for Changes

.These changes clarify the PORC membership and reflect a change in plant

-organization.- These organizational changes were made to standardize the Browns Ferry organization with other TVA nuclear plants.

Desc' iption of Chat ge r

' Units'1 and 2 - page 336 Un'it 3 - page 366 This change corrects a typographic error (changes "porposed" to

" proposed").

Description of Change Units 1 and 2 - page 358 Unit 3 - page1388 This changes the word "the" to "an" to reflect the fact that there are three assistant plant superintendents.

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- c Units l'cnd 2 - p:ga 362 l-Unit 3 - page 392-r This, figure represents current plant organization.

Reason / Justification for Changes f:

These changes reflect a change in plant organization. This i

' reorganization helps standardize Browns Ferry Nuclear Plant organization with other TVA nuclear plants'.

Description of Change r

Units 1 and 2 - pages 361, 363 I

Unit 3 - pages 391, 393 These' change the names of the responsible organizations or individuals within TVA from " Division of Power Production" and " Nuclear Generation Branch".o " Manager of Power Operations" and " Division of Nuclear Power."

Reason / Justification for Changes

' These changes reflect organizational changei which ' resulted, from the separation of TVA's Divi.sion c.f Power Production into the Division of Nuclear Power and 'the Division of Fossil and Hydro Power.

Description of Changes -

. Units 1 and 2 - page 364 Unit 3. - page 394 H

This change assigns responsibility for the overall administration of the

' plant. fire ~ protection and prevention program to an assistant plant superintendent rather than the plant superintendent.

Reanon/ Justification for the Change g

- This change-reflects a change in plant organization to standardize Browns I

Ferry Nuclear Plant organization with other TVA nuclear plants.

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SAFETY ANALYSIS-All changes:in this subm'ittal reflect in-house organizational changes

' arisingLfrom either.the separation of-TVA's Division of Power Production

- ineo'the. Division'or Nuclear Power and the Division af Fossil and Hy'ro d

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' Power or the standardization' of Browns Perry ' organization with TVA's

other; nuclear p.? ants. Based on this fact these changes will.have no

- adverse effect on-the nuclear or environmental safety of Browns Ferry Nuclear Plant e

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