Text

Application for Amend to License NPF-43,revising Requirements Associated W/Containment Oxygen & Hydrogen Monitors
	ML20217P560
Person / Time
Site:	Fermi
Issue date:	04/02/1998
From:	Gipson D; DETROIT EDISON CO.
To:	; NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20217P566	List: ML20217P569; NRC-98-0057, Application for Amend to License NPF-43,revising Requirements Associated W/Containment Oxygen & Hydrogen Monitors;
References
	CON-NRC-98-0057, CON-NRC-98-57 NUDOCS 9804100123
	Download: ML20217P560 (15)
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Douglas R. Gipson

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Senior Vice President, Nudear Generatit.n Fermi 2 f>440 North Dixie liwy, New port, Michigan 48166 Tel: 313 TM.T>201 Fat 313.T.xR4172 Detroit Edison 7

10CFR50.92 April 2,1998 NRC-98-0057 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington D C 20555-0001 i

References:

1) Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43

2) Detroit Edison Letter, NRC-97-0116, Reply to Notice of Violation 50-341/97013-02, dated November 26,1997

3) NRC Inspection Report No. 50-341/97013, dated October 27,1997

4) Fermi 2 Licensee Event Report No. 97-004-01, dated August 1,1997

5) NRC Inspection Report No. 50-341/97002, dated June 2,1997

6) Fermi 2 Licensee Event Report No. 97-004-00, dated April 3,1997

7) NRC Inspection Report No. 50-341/96016, dated March 3,1997

Subject:

Proposed Technical Specification Change (License Amendment) for Drvwell Oxycen Monitors Pursuant to 10 CFR 50.90, the Detroit Edison Company proposes to amend the Fermi 2 plant Operating License NPF-43, Appendix A, Technical Specifications (TS), to revise Technical Specifications requirements associated with the containment oxygen and hydrogen monitors. The proposed change will: (1) change nomenclature for the hydrogen and oxygen monitors;(2) increase the calibration g i frequency for the oxygen monitoring channel consistent with vendor

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USNRC NRC-98-0057 Page 2 recommendations; and, (3) permit delaying the performance ofinstrument calibrations until suitable conditions are established.

The hydrogen and oxygen monitors are part of the Primary Containment Monitoring

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System (PCMS). The PCMS is post accident monitoring instmmentation which provides control room operators with information regarding hydrogen and oxygen concentration following an accident. The Hydrogen / Oxygen (H/0 ) system consists 2

of two divisions, each division including one channel for each parameter. The H/0 2 system continuously samples the containment atmosphere. One division is normally aligned to the drywell, with the other division aligned to the torus. The hydrogen and oxygen monitors each utilize an electrochemical cell.

j The electrochemical cells contain electrodes and an electrolyte. A membrane separates the electrolyte from the gas sample. The electrodes, electrolyte and membrane are selected to make the cell responsive to a particular gas ofinterest (e.g.,

i hydrogen or oxygen). The cell produces a voltage which is a function of the concentration of the gas ofinterest in the electrolyte. Because the sample gas diffuses through the cell membrane into the electrolyte, the concentration of a particular gas in the electrolyte is proportional to the concentration of that gas in the sample. The sample gas continuously flows through an outer chamber and is normally directly exposed to the cell membrane through the inner chamber. During calibration, the calibration gas is injected into the inner chamber, displacing the sample gas which continues to flow through the outer chamber. Thus, the cell membrane sees only the calibration gas during calibration. The calibration itselfis controlled by the instrument's microprocessor which determines the appropriate calibration factors that correlate cell output to calibration gas concentration, including compensation for temperature of the sample gas which continues to flow during the calibration cycle.

During power operation, the containment is inerted with nitrogen gas as required by Technical Specifications to maintain a deliberately low concentration of oxygen in the containment atmosphere. During plant shutdown for refueling and maintenance, the containment is de-inerted with air (approximately 20% oxygen) to permit personnel access. Technical Specifications currently require the hydrogen monitor to be calibrated quarterly and the oxygen monitor to be calibrated once every eighteen months. However, the hydrogen and oxygen monitors are calibrated quarterly based on vendor recommendations. Therefore, Detroit Edison proposes to revise the TS Surveillance interval for the oxygen monitor to quarterly to reflect current practice and vendor recommendations.

Normally these calibrations occur during plant operation with the containment inerted. However,if the plant experiences an outage when the surveillance lapses,

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NRC-98-0057 Page 3 the monitors would be calibrated with the containment de-inerted. References 2 through 7 are related to a phenomena which was discovered to occur when the oxygen monitors are calibrated with the containment de-inerted. As reported in LER 97-004, References 4 and 6, the oxygen monitors exhibit a zero-shift when calibrated in other than a nitrogen environment. Thus, if the monitor is calibrated while operating in a de-inerted environment during an outage, the monitor would be inaccurate and inoperable as soon as the transition is made to an inerted environment when the containment is inerted on startup.

Tests conducted at Fermi and at the vendor's facility confinned this phenomena.

The testing conducted at Fermi demonstrated that the oxygen monitors could be calibrated with the containment de-inerted by simulating an inerted environment by purging the instrument with humidified nitrogen for approximately eight hours before running the calibration. Although it is possible to calibrate the instrument in this manner, this method of calibration places greater reliance on manual operations.

For example, the nitrogen purge gas pressure must be manually set to match the normal sample gas pressure to provide for accurate calibration. While possible, this method is neither considered to be practical or desirable. Under these circumstances, it is more desirable to wait until appropriate conditions are established after the containment has been inerted, when a normal routine calibration can be accomplished without extraordinary measures.

Accordingly, Detroit Edison proposes an exception to Specification 4.0.4 for the hydrogen and oxygen monitor calibrations. Specification 4.0.4 requires that surveillance requirements be completed prior to entry into an operational condition where the subject equipment is required to be operable. Since the containment is required to be inerted within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months afler the plant exceeds 15% power, Detroit Edison proposes that the 4.0.4 exception be keyed to this Technical Specification requirement. The proposed 4.0.4 exception would require completion of the calibration of one channel within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months and the second channel within seven days after exceeding 15% power. provides a description and evaluation of the proposed TS changes. provides an analysis of the issue of significant hazards consideration using the standards of 10 CFR 50.92. Enclosure 3 provides marked up pages of the existing TS to show the proposed changes and a typed version of the affected Technical Specification pages with the proposed changes incorporated.

Detroit Edison has evaluated the pmposed TS changes against the criteria of 10 CFR 50.92 and determined that they do not involve a significant hazards consideration. The Fermi 2 Onsite Review Committee has reviewed and recommended approval of the proposed TS changes. The Nuclear Safety Review

USNRC' NRC-98-0057

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Group has reviewed the proposed TS changes and concurs with the enclosed determinations. In accordance with 10 CFR 50.91, " Notice for Public Comment;.

State Consultation," Detroit Edison is providing a copy of this letter to the State of l

' Michigan.

Detroit Edison requests that the.NRC approve and issue these changes by September 30,1998 with an implementation period of within 90 days following NRC approval.

l Should you have any questions or require additional information, please contact Mr. Norman K. Peterson, Director - Nuclear Licensing, at (734) 586-4258.

Sincerely,

.f 1

1 Enclosures l-cc:

A. B. Beach B. L. Burgess G. A. Harris A. J. Kugler Supervisor, Electric Operators, Michigan Public Service Commission l

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USNRC NRC-98-0057 Page5 I, DOUGLAS R. GIPSON, do hereby affirm that the foregoing statements are based on facts and circumstances which are true and accurate to the best of my knowledge and belief.

b DOUGLAS R.'GlPSON Senior Vice President, Nuclear Generation On this M day of !

s'.1998 before me personally appeared Douglas R. Gipson, being first8uly sworn and says that he executed the

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foregoing as his free act and deed.

M Notary Public ROSEIE A. ARWTTA YM5NWM,8 tW 4

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E closure 1 to NRC-98-0057 P,4ge 1 ENCLOSURE 1 FERMI 2 NRC DOCKET NO. 50-341 NRC LICENSE NO. NPF-43 REQUEST TO REVISE TECHNICAL SPECIFICATIONS:

DRYWELL OXYGEN MONITORS DESCRIPTION AND EVALUATION OF THE PROPOSED CHANGES

\\ to NRC-98-0057 Page 2 DESCRIPTION AND EVALUATION OF THE PROPOSED CHANGES DESCRIPTION:

The proposed charge revises Technical Specification 3.3.7.5, Accident Monitoring Instrumentation. Technical Specification 3.3.7.5, Table 3.3.7.5-1, Item 9, requires

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two Drywell Oxygen Concentration instrument channels to be operable when the plant is in Operational Conditions 1 or 2. Technical Specification 3.3.7.5, Table 3.3.7.5-1, Item 10, requires two Drywell Hydrogen Concentration instrument g

channels to be operable when the plant is in Operational Conditions 1 or 2. Action 80 applies in the situation that the specified number ofchannels are not operable.

With one channel inoperable, Action 80 permits seven days to restore the inoperable j

channel, otherwise the plant is to be shutdown within the following 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . With two channels inoperable, one must be restored within 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months , otherwise the plant must be shutdown within the following 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

Surveillance Requirements for the drywell oxygen and hydrogen monitors are specified in Table 4.3.7.5-1. Monthly channel checks are required for both the oxygen and hydrogen monitors. Calibrations are required at eighteen month j

intervals for the oxygen monitors, and quaderly for the hydrogen monitors.

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The proposed change would revise the nomenclature in Tables 3.3.7.5-1 and 4.3.7.5-1 for the oxygen monitor from "Drywell Oxygen Concentration" to " Primary Containment Oxygen Concentration." Similarly,"Drywell Hydrogen Concentration" would be revised to " Primary Containment Hydrogen Concentration." The purpose of this change is eliminate potential confusion over the number of channels of each instrument and the normal alignment. There are two i

divisions of the Primary Containment Monitoring System. The hydrogen and oxygen monitors are part of the Primary Containment Monitoring System (PCMS).

The PCMS is post accident monitoring instrumentation which provides control room operators with infonnation regarding hydrogen and oxygen concentration following an accident. As described in the UFSAR, the H /0 system consists of two divisions, 2 2 each division including one channel for each parameter. The H /0 system 2 2 continuously samples the containment atmosphere during Operational Conditions I and 2 when required to be operable by the Technical Specifications. Each division can be aligned to monitor either the drywell or the torus. One division is normally aligned to the drywell, with the other division aligned to the torus. This change will eliminate potential confusion.

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NRC-98-0057 Page 3 4

The proposed change would revise the calibration frequency for the Primary Containment Oxygen Monitoring Channels. Table 4.3.7.5-1 currently requires calibration at eighteen month intervals. The vendor recommends quarterly calibration. Accordingly, the proposed change revises the surveillance interval for the Primary Containment Oxygen Monitoring Channels to quarterly consistent with the vendor recommendations.

The proposed change would add an exception to Specification 4.0.4 to Table 4.3.7.5-1 for entry into Operational Conditions 2 and 1, for the Primary Containment Oxygen and Hydrogen Monitoring Channels. Specification 4.0.4 requires that surveillance requirements be completed prior to entry into an operational condition where the subject equipment is required to be operable. The proposed 4.0.4

. exception would require completion of the calibration of one channel within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , and the second channel within seven days after exceeding 15% power.

Technical Specification 3/4.6.6.2, Drywell and Suppression Chamber Oxygen Concentration, requires the containment to be inerted (i.e., <4% oxygen) within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after the plant exceeds 15% power. This change will permit establishment of appropriate conditions for calibration of the oxygen monitors.

EVALUATION OF THE PROPOSED CHANGE (Sh Fermi 2 has an inerted primary containment atmosphere during reactor operation.

Because of this, in the event of a LOCA, the oxygen concentration is the limiting parameter for preventing the accumulation of an explosive gas mixture. The hydrogen and oxygen concentrations are monitored during operation and following a LOCA by the Primary Containment Hydrogen / Oxygen Monitors, and are displayed in the control room. The hydrogen and oxygen monitors are part of the Primary i

Containment Monitoring System (PCMS). The H /0 system consists of two j

2 2 divisions, each division including one channel for each parameter. The H /0 system 2 2 continuously samples the containment atmosphere during Operational Conditions 1 and 2 when required to be operable by the Technical Specifications. One division is j

normally aligned to the drywell, with the other division aligned to the torus. The Primary Containment Oxygen Monitors provide information to the Control Room operators to ensure the detection of oxygen concentrations in the primary containment so that actions can be initiated, if necessary, to prevent the accumulation of an explosive gas mixture. Technical Specification 3.3.7.5 requires the Primary Containment Hydrogen and Oxygen Monitors to be operable in Operational Conditions 1 and 2. In addition, Technical Specification 3.6.6.2 requires the drywell and suppression chamber oxygen concentration to be less than 4% by volume within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after thermal power is greater than 15% of Rated Thermal Power following

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startup.

to NRC-98-0057 Page 4 The hydrogen and oxygen monitors each utilize an electrochemical cell. The 4

electrochemical cells contain electrodes and an electrolyte. A membrane separates the electrolyte from the gas sample. The electrodes, electrolyte and membrane are selected to make the cell responsive to a particular gas ofinterest (e.g., hydrogen or oxygen). The cell produces a voltage which is a function of the concentration of the gas ofinterest in the electrolyte. Because the sample gas diffuses through the cell

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membrane into the electrolyte, the concentration of a particular gas in the electrolyte is proportional to the concentration of that gas in the sample. The sample gas continuously flows through an outer chamber and is normally directly exposed to the cell membrane through the inner chamber. During calibration, the calibration gas is injected into the inner chamber, displacing the sample gas which continues to flow through the outer chamber. Thus, the cell membrane sees only the calibration gas during calibration. The calibration itselfis controlled by the instrument's microprocessor which determines the appropriate calibration factors that correlate cell output to calibration gas concentration, including compensation for temperature of the sample gas which continues to flow during the calibration cycle.

During power operation, the containment is inerted with nitrogen gas as required by

]

Technical Specifications to maintain a deliberately low concentration of oxygen in the containment atmosphere. During plant shutdown for refueling and maintenance, the containment is de-inerted with air (approximately 20% oxygen) to permit personnel access. The hydrogen and oxygen monitors are calibrated quarterly based on vendor recommendations. Normally these calibrations occur during plant operation with the containment inerted. However, if the plant experiences an outage when the surveillance lapses, the monitors would be calibrated with the containment de-inerted.

LER 97-004, and its supplement, reported a phenomenon which was discovered to occur when the oxygen monitors are calibrated with the containment de-inerted. As described in the LER, the oxygen monitors exhibit a zero-shift when calibrated in other than a nitrogen environment. Thus,if the monitor is calibrated while operating in a de-inerted environment during an outage, the monitor would be decalibrated and inoperable as soon as the transition is made to an inerted environment when the containment is inerted on startup. Technical Specifications would prohibit this transition from being made.

Tests conducted at Fermi and at the vendor's facility confirmed this phenomenon.

The testing conducted at Fermi demonstrated that it is possible to adequately calibrate the oxygen monitors with the containment de-inerted by simulating an inerted environment by purging the instrument with humidified nitrogen for

1 Enclosure I to NRC-98-0057 Page 5 l

approximately eight hours before running the calibration. Although it is possible to calibrate the instrument in this manner, this method of calibration places greater reliance on manual operations. For example, the nitrogen purge gas pressure must be manually set to match the normal sample gas pressure to provide for accurate calibration. While possible, this method is neither considered to be practical or desirable. Under these circumstances, it is more desirable to wait until appropriate conditions are established after the containment has been inerted, when a normal routine calibration can be accomplished without extraordinary measures.

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The proposed exception to Specification 4.0.4 would permit the establishment of I

appropriate conditions to perform a normal routine calibration of the oxygen monitor. Although, the hydrogen monitor is unaffected by this zero-shin 1

phenomenon, the hydrogen and oxygen monitors are both part of the PCMS using the same sample loop. The calibrations are conducted in parallel by the same surveillance procedure. Separating the calibrations would result in the monitors being made inoperable twice, once for each calibration. The 4.0.4 exception is i

applied to both monitors for consistency.

This provision is only necessary if the plant were to experience an extended outage where the surveillance lapses. This is expected to be an infrequent occurrence. In this circumstance, the proposed change would allow the plant to restart and the performance of the calibration to be delayed a few days until appropriate conditions are established. This delay is reasonable considering the function of the hydrogen and oxygen monitors.

The Primary Containment Oxygen Monitors provide information to the Control Room operators to ensure the detection of oxygen concentrations in the primary containment so that actions can be initiated, if necessary, to prevent the accumulation of an explosive gas mixture. The monitors are also used to verify the adequacy of mitigating actions. The potential for a LOCA at or below 15% Rated Thermal Power wherein significant quantities of hydrogen will be generated is small. Therefore, in accordance with LCO 3.6.6.2, inerting of primary containment during plant startup is required to be completed within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months aner thermal power is greater than 15%

Rated Thennal Power. Thus, it is reasonable to allow the initial calibration of the Containment Hydrogen and Oxygen Monitors during plant startup to be delayed until containment inerting activities have been completed. The proposed 4.0.4 exception permits 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to calibrate one channel and seven days to complete both after 15%

power is exceeded. Thus, the maximum duration of the Specification 4.0.4 exception beyond the time when the containment is required to be inerted is limited to 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months for calibration of one channel. For comparison, the current allowed out of service times for these monitors included in Action 80 are 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months with both channels

- to NRC-98-0057

- Page 6 inoperable and seven days with one channelinoperable. As additionaljustification, NUREG-1433, Rev.1, BWR/4 Standard Technical Specifications, permits entry into the Applicable Conditions with inoperable post accident monitoring equipment, including the hydrogen and oxygen monitors, due to the passive function of the instrumentation; the operators' ability to diagnose an accident using alternative instruments and methods; and the low probability of an event requiring these instruments during the allowed out of service time. Experience has shown that on eight hour soak time is required aRet the primary containment has been inerted before calibration. Calibration typically requires in excess of two shifts to complete.

I The proposed change would revise the nomenclature in Tables 3.3.7.5-1 and 4.3.7.5-1 for the oxygen monitor from "Drywell Oxygen Concentration" to " Primary Containment Oxygen Concentration." Similarly,"Drywell Hydrogen Concentration" would be revised to " Primary Containment Hydrogen Concentration." The purpose of this change is to eliminate potential confusion over the number of channels of each instrument and the normal alignment. There are two divisions of the Primary Containment Monitoring System. The hydrogen and oxygen monitors are part of the Primary Containment Monitoring System (PCMS).

The PCMS is post accident monitoring instmmentation which provides control room operators with information regarding hydrogen and oxygen concentration following

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an accident. The H /0 system consists of two divisions, each division including one 2 2 channel for each parameter. The H /0 system continuously samples the 2 2 containment atmosphere during Operational Conditions 1 and 2 when required to be Operable by the Technical Specifications. As described in the UFSAR, each division' can be aligned to monitor either the drywell or the torus. One division is normally aligned to the drywell, with the other division aligned to the torus. This change will eliminate potential confusion.

Finally, the proposed change would revise the calibration frequency for the Primary Containment Oxygen Monitoring Channels. Table 4.3.7.5-1 currently requires calibration at eighteen month intervals. The vendor recommends quarterly calibration. Accordingly, the proposed change revises the surveillance interval for the Primary Containment Oxygen Monitoring Channels to quarterly to be consistent with the vendor recommendations.

. SIGNIFICANT HAZARDS CONSIDERATION:

In accordance with 10 CFR 50.92, Detroit Edison has mad-a determination that the proposed amendment involves no significant hazards consideration. To make this determination, Detroit Edison has established that operation in accordance with the proposed TS amendment would not:

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~ NRC-98-0057 Page 7 I

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.

The significant hazards consideration assessment is provided in Enclosure 2.

l ENVIRONMENTAL IMPACT:

Detroit Edison has reviewed the pmposed TS changes against the criteria of 10 CFR 51.22 for environmental considerations. The proposed changes do not involve a significant hazards consideration, nor significantly change the types or

~ igni_ficantly increase the amounts of effluents that may be released ofTsite, nor.

s significantly increase individual or cumulative occupational radiation exposures.

Based on the foregoing, Detroit Edison concludes that the proposed TS changes meet the criteria provided in 10 CFR 51.22(c)(9) for a categorical exclusion from the requirements for an Environmental Impact Statement and an Environmental Assessment.

CONCLUSION:

Based on the evaluation above: (1) there is reasonable assurance that the health and safety.of the public will not be endangered by operation in the proposed manner, and

. (2) such activities will be conducted in compliance with the NRC's regulations and the proposed amendment will not be inimical to the common defense and security, or to the health and safety of the public.

i Detroit Edison requests that the proposed license amendment be approved by the NRC, with implementation to occur within the following 60 days.

to NRC-98-0057 Page1 ENCLOSURE 2 FERMI 2 NRC DOCKET NO. 50-341 NRC LICENSE NO. NPF-43 REQUEST TO REVISE TECIINICAL SPECIFICATIONS:

10 CFR 50.92 SIGNIFICANT IIAZARDS CONSIDERATION I

Enclosare 2 to NRC-98-0057 Page 2 10 CFR 50.92 SIGNIFICANT IIA 7,ARDS CONSIDERATION HASIS FOR SIGNIFICANT IIAZARDS DETERMINATION In accordance with 10CFR50.92, Detroit Edison has made a determination that the proposed amendment involves no significant hazards consideration. The proposed 1

Technical Specification (TS) changes described above do not involve a significant hazards consideration for the following reasons:

1. The changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.

The proposed change will permit delaying the performance of calibrations of the hydrogen and oxygen monitors until after the containment is inerted following a plant startup. The proposed change will also increase the calibration frequency for the oxygen monitors from once per 18 months to once per quarter, and change the nomenclature for the hydrogen and oxygen monitors.

The primary containment hydrogen and oxygen monitors are passive instruments that provide indication to control room operators of hydrogen and oxygen concentration in the primary containment. Because they perform only a passive monitoring function, the hydrogen and oxygen monitors are not associated with the initiation of any previously evaluated accident. The indication provided by the.nonitors is used by the control room operators to ensure oxygen concentration remains below limits and to make decisions regarding the use of the Combustible Gas Control System, if necessary. The allowance to permit entry into applicable operational conditions before calibration assures that the conditions (nitrogen emironment) are appropriate for accurate calibration of the instrument. Delaying the calibration does not cause the instrument to cease to function. Calibrations verify and adjust, as necessary, the accuracy of the instrument to compensate for drift that may occur since the last calibration.

Thus, even with a delayed calibration, the instruments still would provide valuable information to the operators. Consequently, this change will not involve a significant increase in the consequences of a previously evaluated accident because the monitors will still function and provide meaningful information until the calibration is completed.

The change to reduce the l'Merval for calibration of the oxygen monitors from once per 18 months to once per quarter provides increased assurance of monitor accuracy and is consistent with the manufacturer's recommendations. Therefore,

. to NRC-98-0057 l

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because this instrument is not associated with the initiation of an accident and the change improves the functionality of the instrument, the probability and consequences of previously evaluated accidents are not significantly affected.

l The change in nomenclature is editorial, and, as such does not affect the probability or consequences of a previously evaluated accident.

2. The changes do not create the possibility of a new or different kind of accident from any accident previously evaluated.

As discussed above, the hydrogen and oxygen monitors are passive, indication-only instruments which provide information to control room operators. The proposed changes do not introduce a new mode ofoperation or involve a physical l

modification to the plant. Therefore, the proposed changes do not create the possibility of a new or different kind of accident from any previously evaluated.

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3. The changes do not involve a significant reduction in the margin of safety.

l The proposed changes involve the containment hydrogen and oxygen monitors which do not affect any parameters or assumptions used in the calculation of any safety margin with regard to Technical Specification Safety Limits, Limiting Safety System Settings, Limiting Control Settings or Limiting Conditions for Operation, or other previously defined margins for any structure, system, or component. Therefore, the proposed changes do not involve a significant reduction in a margin of safety.

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NRC-98-0057, Application for Amend to License NPF-43,revising Requirements Associated W/Containment Oxygen & Hydrogen Monitors

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References:

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