BECO-86-136, Application for Amend to License DPR-35,consisting of Proposed Change 86-09,making Permanent short-term Change Noted in Amend 86 Re Operation of Main Steam Line W/Hydrogen Injection Into Reactor Coolant.Fee Paid

Application for Amend to License DPR-35,consisting of Proposed Change 86-09,making Permanent short-term Change Noted in Amend 86 Re Operation of Main Steam Line W/Hydrogen Injection Into Reactor Coolant.Fee Paid

ML20203N200
Person / Time
Site:	Pilgrim
Issue date:	09/09/1986
From:	Lydon J BOSTON EDISON CO.
To:	Zwolinski J Office of Nuclear Reactor Regulation
Shared Package
ML20203N202	List: BECO-86-136, Application for Amend to License DPR-35,consisting of Proposed Change 86-09,making Permanent short-term Change Noted in Amend 86 Re Operation of Main Steam Line W/Hydrogen Injection Into Reactor Coolant.Fee Paid ML20203N209
References
BECO-86-136, NUDOCS 8609230208
Download: ML20203N200 (6)

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-amu Executive offices 800 Boylston Street Boston, Massachusetts 02199 Proposed Change 86-09 September 9, 1986 James M. Lydon Chief operating officer BECo 86-136 Mr. John A. Zwolinski, Director BHR Project Directorate #1 Division of Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D. C. 20555 License DPR-35 Docket 50-293 Proposed Technical Specification Change to Allow Hydrogen Injection

Dear Sir,

By letter of April 5, 1985 the NRC transmitted Amendment No.86 to Facility Operating License No. DRR-35 for the Pilgrim Nuclear Power Station. This responded to our request for change transmitted by letters of February 1, 1985 and February 15, 1985. The change added a note to Tables 3.1.1 and 3.2.A permitting changes in the normal full power background trip level for the main steam line high radiation scram and isolation setpoints to accommodate a short-term test of operation with hydrogen injection into the reactor coolant.

Boston Edison has concluded, based on the testing, that hydrogen injection is desirable at Pilgrim Station as a mitigator of intergranular stress corrosion cracking (IGSCC) in stainless steel piping. To permit future injection, we herein submit a request for amendment to our license which removes reference to short-term testing in the note, and thereby makes permanent the change granted in Amendment No.86.

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. BOSTON EDIS0N COMPANY September 9,1986 Page 2 Should you wish further information concerning this proposal, please contact us.

Ve y truly yours,-

>w., & tlw Attachment Three signed originals and 37 copies cc: see next page Commonwealth of Massachusetts)

County of Suffolk )

Then personally appeared before me, James L. Lydon, who, being duly sworn, did state that he is Chief Operating Officer of Boston Edison Company and that he is duly authorized to execute and file the submittal contained herein in the name and on behalf of Boston Edison Company and that the statements in said submittal are true to the best of his knowledge and belief.

My commission expires: Mg,,/3,/992 h '

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DATE NOTARY PUBLIC Cmafd G. Wktney Notary Public My Commission gy,,,, Agn,3, y997

~ BOSTON EDISON COMPANY September 9 -1986 Page 3 d

cc: Mr. Robert M. Hallisey, Director Radiation Control Program Mass. Dept. of Public Health 150 Tremont Street F-7 Boston, MA' 02111 t

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Proposed Change Reference is made to Pilgrim Operating License No. OPR-35, Appendix A, pages 29 and 46. Pages 27 and 45 are provided for reference. Page 27 contains Table 3.1.1, " Reactor Protection System (SCRAM) Instrumentation Requirement,"

and page 29 provides notes associated with that table. Page 45 contains Table 3.2.A, " Instrumentation That Initiates Primary Containment Isolation", and Page 29 provides notes associated with that table.

Currently, Table 3.1.1 states that the main steam line high radiation trip level setting is "<7x Normal Full Power Background, and references Note (18)." This applies to Refuel, Startup, Hot Standby and Run modes.

The desired amendment would change Note (18) by deleting the word " test" wherever it currently appears. Note (18) shall now state:

Within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to the planned start of hydrogen injection with the reactor power at greater than 20% rated power, the normal full power radiation background level and associated trip setpoints may be changed based on a calculated value of the radiation level expected during the injection of hydrogen. The background radiation level and associated trip setpoints may be adjusted based on either calculations or measurements of actual radiation levels resulting from hydrogen injection. The background radiation level shall be determined and associated trip setpoints shall be set within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of re-establishing normal radiation levels after completion of hydrogen injection, or prior to withdrawing control rods at reactor power levels below 20% rated power.

Table 3.2.A includes the main steam line high radiation instrumentation. The proposed change will delete the word " test" in Note (9) of page 46, resulting in the identical wording of the above note.

Reason for Change This amendment is proposed to permit changes in the normal full power background trip level setting for the Main Steam Line High Radiation scram and isolation setpoints to allow hydrogen injection as an IGSCC mitigating activity.

The purpose of hydrogen injection is to allow Boston Edison to employ hydrogen water chemistry as a mitigator of intergranular stress corrosion cracking (IGSCC) of stainless steel BHR piping. This technique consists of adding hydrogen to the primary coolant to lower the free oxygen concentration by suppressing radiolysis of water. By reducing free oxygen, one of the three necessary causative agents of IGSCC is eliminated. Testing of hydrogen injection as a mitigator was conducted at Pilgrim, and experience gained from that testing indicates that the injection of hydrogen will benefit Pilgrim Station.

In sum, the purpose of employing hydrogen water chemistry is to effect the following benefits:

1. The elimination or reduction of IGSCC concerns.

2. The elimination of the costly replacem nt or repal'r of IGSCC, as well as the lost plant availubility associated with<such activities.

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3. The reduction of radiation exposure to personnel engaged in pipe crack repairs and non-destructive ex'ami' nations which stem from IGSCC.

When hydrogen is injected for oxygen suppression, nitrogen (N-16) carry-over increases in the main steam, which increases r.adiation in areas where main steam is found. The increased carry-over and radiation is caused by a conversion of N-16 from a soluble to a volattie form in the reactor.

The requested revision of Tables 3.1.1 .and 3.2.A, and the addition of notes (18) and (9) permit an increase in the hain Steam Line High Radiation scram and isolation setpoints to allow operation with the higher radiation levels resulting from hydrogen injection. The main steam high radiation setpoint will remain at "I 7 Normal Full Power Background"; however, because of increased N-16 in the steam, the background radiation level used to determine the high radiation setpoint will be increased grior to injection in accordance with a predetermined background level value. These will permit the full load background radiation level to be adjusted such that spurious scrams are avoided. Pre-injection setpoints will be restored following the conclusion of injection, or when power is decreased to below 20% power. Hydrogen injection will not be performed with the reactor at less than 20% power.

Safety Considerations At the planned hydrogen injection rate, experience indicates an expected increase of approximately 3 to 8 times the normal main steam line background radiation level. The only event which takes credit for the main steam line high radiation (MSLRM) trip is the design basis control rod drop accident (CRDA). As stated in Section 14.7.1.2 of the Pilgrim FSAR, a CRDA is only of concern below 10% of rated power. Since the Main Steam Line Radiation Monitor (MSLRM) setpoint will be adjusted at power levels above 20% power, the FSAR analysis and the design functiontof the MLSRM trip will remain valid. An increase in the HSLRM setpoint will not impact any other FSAR Chapter 14 accident or transient analysis since no credit is taken for MSLRM trips.

Therefore, this proposed technical specification change will not reduce plant safety margins. In addition, the effect of hydrogen injection on the gaseous effluent release rate is expected to be insignificant because of the short decay time for N-16.

I Hydrogen injection testing has provided data which resulted in additional shielding and procedural changes such that personnel exposure is minimized during injection. Likewise, steps have been taken so that- injection will not have a significant impact on.the public.

This proposed change has been reviewed and approved by the Operations Review Committee (ORC), and reviewed by the Boston Edison Nuclear Safety Review and Audit Committee (NSRAC).

St9nificant Hazards Considerations

. The Commission has provided guidance concerning th'e application of the standards for determining whether license amendments involve no significant hazards considerations by providing certain examples (48 FR 14870). Example

(vi) of actions involving no significant hazards consideration is a change l

which may reduce in some way a safety margin,.but where the results of the

-change are clearly within all acceptable criteria. The change proposed by this applications fits this example because it would permit the normal full power background level, associated with the Main Steam High Radiation scram and isolation setpoints, to be increased only so as to compensate for the increase in the main steam radiation levels during hydrogen injection. The capability to monitor for fuel failures, which is the mission of the MSLR trip setpoint, is maintained-by: .1) ( the continued operability of the main steam radiation monitors, which provide signals to the reactor protection system and primary containment isolation system; (2) routine radiation surveys; (3) the performance of primary coolant water analyses; and (4) the continued operability of the Steam Jet-Air Ejector Off-Gas . Radiation Monitor.

Although the potential for error exists whenever instrument setpoints are adjusted, the resulting increase in the probability or consequences of accidents previously evaluated is considered insignificant because cf Boston Edison's existing quality assurance program and operating procedures as

-applied to instrument adjustments.

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If, due to a recirculation pump trip or other unanticipated power reduction event, the reactor drops below 20% rated power without setpoint readjustment, control rod withdrawal is prohibited until the necessary setpoint readjustment is made. This ensures that fuel failures of the type concerning the MSLRM are unlikely.

Radiation protection practices will be performed during hydrogen injection -

based upon injection test data. Steps have been taken to make changes to plant design and procedures deemed appropriate to minimize personnel exposure during the injection of hydrogen. Changes in gaseous effluent release rates for hydrogen injection are negligible due to the short decay times for N-16.

Based on the diverse means for maintaining the ability to detect fuel failures, on the protection of primary coolant system piping promised by

, implementing hydrogen water chemistry, on the efficacy of programs and l procedures to assure accurate instrument setpoint adjustment, on both routine

! and exceptional ALARA actions which have been taken, on the ability of j- existing technical specifications to ensure that inimical control rod movement cannot occur below 20% power, and on the insignificant effect of increased l N-16 activity on gaseous effluent release rates, Boston Edison concludes that l the proposed amendment will not significantly increase the probability or consequences of accidents previously considered, will not create the possibility of a new or different accident from any previously evaluated, and will not significantly reduce a safety margin. Therefore, Boston Edison proposes to the NRC that it should make a determination that the proposed amendment does not involve significant hazards considerations.

Schedule of Change This change will become effective upon Boston Edison's receipt of approval by the NRC. It is our intention to becin injection concomitant with startup from RF0 #7.

Fee Determination Pursuant to 10CFR 170.12 (c), an appilcation fee of $150.00 is included with this proposed amendment.

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