ML20024F111

Application to Amend License DPR-16 Consisting of Tech Spec Change Request 117,allowing for Addition of Tenth Range to Neutron Monitoring Sys Intermediate Range Monitors

ML20024F111
Person / Time
Site:	Oyster Creek
Issue date:	09/02/1983
From:	Fiedler P GENERAL PUBLIC UTILITIES CORP.
To:	Office of Nuclear Reactor Regulation
Shared Package
ML20024F110	List: ML20024F109 ML20024F111 ML20024F112
References
NUDOCS 8309080239
Download: ML20024F111 (11)

Text

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OYSTER CREEK IUCLEAR GENERATING STATION PROVISIONAL OPERATING LICENSE 10. DPR-16 TECHNICAL SPECIFICATION CHANGE REQUEST 10.117 DOCKET NO. 50-219 Applicant submits by this Technical Specification Change Request Ib.117 to the Oyster Creek Nuclear Generating Station Technical Specifications, changes to Specifications 2.3.1.b, 2.3.7, 3.3, Tables 3.1.1 and 4.1.1.

By W M4 O Pet'er B. Fiedler Vice President and Director Oyster Creek Sworn and subscribed to before me this dnh day of Q V n W 1983.

kMD Notary Public

%Od MNICE L CONDEMORE '

NOTM't t'UOL!c cf ,;Eg Jtg3EY Wi Carsca Expe uj n, n35 1

8309080239 830902 PDR ADOCK 05000219 p PDR

UNITED STATES OF AMERICA WCLEAR REGJLA1 DRY COMMISSION IN THE MATTER OF )

) DOGET NO. 50-219 GPU WCLEAR G)RIORATION )

GRTIFICATE OF SERVIG This is to rtify that a copy of Ibchnical Specification Changa Request No.117 for the Oyster Creek Riclear Gmerating Station '1bchnical Specifications, filed with the United States Nuclear Regulatory Camaission

. cn September 2 ,1983, has this day of September 2 ,1983, been served cn the Mayor of La y 'Ibwnship, Ocean County, New Jersey by deposit in the thited States mail, addressed as follows:

The Hcncrable Thcznas R. mskwich Mayor of La y Township 818 West la y Road Forked River, E 08731 Bf { V >A b Peter B. Fiedler Vice Presidst and Director Oyster Creek PBF: dam

GPU Nuclear u GM P.O. Box 388 Forked River, New Jersey 08731 609-693-6000 Writer's Direct Dial Number:

September 2, 1983 The Ilonorable Thomas R. mskovich Mayor of Lacey 'Ibwnship 818 West lamy Road Forked River, PU 08731

Dear Mayor W3skovich:

Enclosed herewith is me copf of the 'Ibchnical Specification Change Request

!b.117 for the Oyster Creek Ibclear Caerating Station Operating License.

This document was filed with the United States Ibclear Regalatory Commission cn September 2 , 1983.

Vay truly yours, Peter B. Fiedler Vice President and Director Oyster Creek PBF: dam Enclosure GPU Nuciear is a part of tne General Pubhc Utikties System

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CPU Nuclear I

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• 388 Forked River, New Jersey 08731 4 609-693-6000 Writer's Direct Dial Number:

September 2, 1983 Mr. Frank Cosolito, Acting Chief Bureau of Radiation Protection Departmcnt of Ehvironmental Protection 380 Scotcil Foad Trcntcn,11ew Jersey 08628

Subject:

Ofster Creek Ibclear Generating Station Provisicnal Operating License Ib. DPR-16 Technical Specification Change Request Ib.117 Pursuant to 10 CER 50.91 (b) (1), please find enclosed a copy of the subject docurrent which was filed with the United States Regulatory Ccmmission cn September 2 , 1983.

Very truly yours, hl Petef B. Fiedler Vice Presidst and Director Oyster Creek FBF: dam Enclosur e h04b GPU Nuclear is a part of the General Public Utilities System

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g OYSTER CREEK IUCLEAR GENERATING STATION PROVISIONAL OPERATING LICENSE NO. DPR-16 DOCKET 10. 50-219 TECHNICAL SPECIFICATION CHANGE REQUEST NO.117 Applicant hereby request the Comraission to change Appendix A to the above captioned license as follows:

1. Sections to be changed:

Sections 2-3.1, 2.3.7, 3.3, Tables 3.1.1 and 4.1.1

2. Extent of changes:

See Attachment 1

3. Changes requested:

See Attache nt 1

4. Discussion:

Oyster Creek has been experiencing difficulty in switching from the STARW P mode to the RUN node without getting a rod withdrawal block. The switch from the STARWP mode to the RUN mode is made when the IRMs are reading about 100 (0 to 125 scale) on range 9, at approximately 10% of reactor power. In going to RUN mode, neutron monitoring is switched from the IRM's to LPRM/APRM's. The problem occurs at this time due to LPRM's reading dowscale which causes a rod block. A sufficient number of LPRM's are downscale, due to the physical location of the LPRMs in the core and the skewed axial flux distribution in the core during a reactor startup, that they cannot all be bypassed within operability limits of Oyster Creek Technical Specifications.

The proposed change will add a tenth range to the IRMs, increasing the neutron monitoring with the IRMs from 10% to approximately 40% of rated power. This will significantly increase the IRM/APRM system overlap and l allow for a smooth transition from STARW P to RUN mode. The switch from STARWP to RUN mode can be performed at a higher power level when the LPRM downscale rod blocks have cleared.

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OYSTER CREEK GENERATING STATION PROVISIONAL OPERATING LICENSE NO. DPR-16 DOCKET 10. 50-219 TECHNICAL SPECIFICATION CHANGE REQUEST 10.117 Pursuant to 10 CFR 50.91, an analysis concerning significant hazards considerations is provided below:

1. Sections to be changed:

Sections 2.3.1, 2.3.7, 3.3, Tables 3.1.1 and 4.1.1

2. Extent of Changes:

See Attachment 1

3. Changes Requested:

See Attachment 1

4. Discussion:

Oyster Creek has been experiencing difficulty in switching from the STARIUP mode to the RUN mode without getting a rod withdrawal block. The switch from the STARIUP mode to the RUN mode is made when the IRMs are reading about 100 (0 to 125 scale) on range 9, at approximately 10% of reactor power. In going to RUN mode, neutron monitoring is switched from the IRM's to LPRM/APRM's. The problem occurs at this time due to LPR4's reading.

downscale which cauces a rod block. A sufficient nunber of LPRM's are downscale, due to the physical location of the LPRMs in the core and the skewed axial flux distribution in the core during a reactor startup, that they cannot all be bypassed within operability limits of Oyster Creek Technical specifications.

The proposed change will add a tenth range to the IRMs, increasing the neutron monitoring with the IRMs from 10% to approximately 40% of rated power. This will significantly increase the IRM/APRM system overlap and allow for a smooth transition from STARTUP to RUN mode. The switch from STAR'IUP to RUN mode can be performed at a higher power level when the LPRM downscale rod blocks have ueared.

A technical evaluation of the proposed change was performed to insure that the affected systems would perform their required safety function.

A rod withdrawal error (RWE) analysis was performed to evaluate the adequacy of the IRM rod block. The RWE transient was initiated at 35%

power. Reactor power is just at the IRM rod block, but the rod block is

not initiated. Since the APRM system response was assumed to be degraded and the IRMs do not provide as much core coverage as LPRM/APRMs, the RWE analysis was performed under a conservation assumption that no nuclear instrumentation would terminate the event. The analysis was performed at peak cycle reactivity and with a xenon free core. A control rod pattern consistent with analyzed power and flow conditions was established. Each control rod was separately withdrawn to the full out position. A final power level was determined for each control rod. A minimum flow of 14.0 M1b/hr (23% of rated flow) was found necessary to insure that a RWE at 35%

power or less would not exceed technical specification transient MCPR limits for operation in range 10. The minimum flow is required to insure the technical specification limit is not violated. Therefore, the minimum flow value itself should be a technical specification limit. The analysis was Cycle 9 specific and does not necessarily bound future cycle operating conditions. The analysis did not include the uncertainties in the heat balance at low power or in the ability of the IRMs to track core average power. In order to insure that the uncertainties above are accounted for and that the RWE in the IRM range will be bounded for future cycles, a minimum recirculation flow of 39.65 Mlb/hr has been established for operation in IRM range 10. Critical Power Ratio (CPR) calculations at this flow indicate that a bundle power of 3.36 MW would be required to give the same initial CPR used in the RWE analysis. This is close to twice the power for the limiting bundle in the RWE analysis at 35% of rated thermal power. With design peaking factors this corresponds to approximately a core thermal power at 60% of rated. Thus, a minimum recirculation flow of 39.65 Mlb/hr for operation in IRM 10 will be conservative. The core flow of 39.65 Mlb/hr is set as a Technical Specification limit by this change request.

The adequacy of the IRM scram was determined by comparing the scram level on the IRM range 10 to the scram level on the APRMs at 30% of rated flow.

The IRM scram is at 38.4% of rated power while the APRM scram is at 52.7%

of rated power. The minimum flow for Oyster Creek is at 30% of rated and this would be the lowest APRM scram point. The increased recirculation flow to 65% of flow will provide additional margin to CPR limits. The APRM scram at 65% of rated flow is 87.1% of rated power, while the IRM range 10 scram remains at 38.4% of rated power. Therefore, transients requiring a scram based on flux excursion will be terminated sooner with a IRM range 10 scram then with an APRM scram. The transients requiring a scram by nuclear instrumentation are the loss of feedwater heating and the improper startup of an idle recirculation loop. The loss of feedwater heating transient is not affected by the range 10 IRM since the feedwater heaters will not be put into service until after the LPRM downscales have cleared, thus insuring the operability of the APRM system. This will be administratively controlled. The improper startup of an idle recirculation loop becomes less sovere at lower power level and the IRM scram would be adequate to terminate the flux excursion.

5. Determination We have determined that the subject change request involves no significant hazards in that operation of the Oyster Creek Nuclear Generating Station in L

accordance with Technical Specification Change Request No.117 would not:

1) Involve a significant increase in the probability or consequences

. of an accident previously evaluated; or

2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or

! 3) Involve a significant reduction in a margin of safety.

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Attachment 1 ,

a Summary ~of' Tech. Spec. Change Request No.~117 ' '

Current Proposed No. Tech. Spec. Tech. Spec. Extent of Change Justification .

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Section 2.3 Limiting Safety Systems Settings

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.1. Specification Specification 438.4 percent of rated neutron flux See Bases Statement, 2.3.1.b 2.3.1.b - paragraph 3 p

' age 2.3-1 page 2.3-1 , ,._ ,

'page 2.3-5

2. Specification Specification <825 prig (Initiated in IRM range ,

See' Bases Statement, j 2.3.7 2.3.7 _,10)( ,

s, paragraph 2 page 2.3-3 page 2.3-3 ' '- page 2.3-5 l

3. Bases Statement Bases Statement Rated flow , to read: 61.0x106 lb /hr Earlier typographical error ,

paragraph 3 paragraph 3 -

had listed rated flow as page 2.3-3 page 2sa-3 , 111 */ . 61.0x105 lb/hr .

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4. Bases Statement Bas s Statement i . . .IRM range 9 -high flux scram In accordance with paragraph 1 'paar'grhph 1 betting of 12% of rated power Specification.2.1.B s page 2.3-5 page 2.3-5 provides adequate thermal margin between the maximum power and the ,

safety limit of 18.3% of rated power...

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5. Bases Statement Bases Statement To continue beyond 12% power, IRMs t

See Extent of Change for paragraph Ic p'ragraph a 2 must be transferred to range 10. Change 2 page 2.3-5 page 2.3-5 To accomplish this reactor pressure must be above 825 psig.

6. Bases Statement IRM range 10 scram set at 38.4% of In accordance.with, Specification paragraph 3 rated power' 2.1.A and the Extent of Change page'2.3-5 t for Change 1 s

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Summary of Tech. Spec. Chan?,b Request No.,117 ,

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Current Proposed ,

No. Tech. Spec. , Tech. Spec. Extent of Change Justification

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Basbs' Statement Maintaining a minimum recirculation See Extent of Change-for'

, paragraph 4 flow of 39.65x106 lb/hr in range 10 Change 10.

page 2.3-5 will preclude violating the fuel 7 cladding safety limit even in the face of a complete rod withdrawal.

initiated at 35% of rated power.

8. Bases Statetr.ent Bases Statement Operation of the reactor at pressures See Extent of Change for paragraph 2 paragraph 2 lower than 825 psig requires that the Changes 2 and 5.

page 2.3-6 page 2.3-6 reactor mode switch be in the Startup position and the IRMs be in range 9, or lower, where protection of the fuel cladding integrity safety limit is provided by the IRM high neutron flux scram.

Section 3.1 Protective Instrumentation

9. Table 3.1.1 Table 3.1.1 Indication of Lo-Pressure in Main See Extent of Change for Section B Section B Steamline Reactor Isolation function Change 2 Line 5 Line 5 being operable in startup mode.

Section 3.3 Reactor Coolant

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Specification Minimum flow for startup 39.65x106 See Bases Statement 3.3.H.3 lb/hr listed. paragraph 4 page 3.3-2a page 2.3-5

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