ML20071D805

Forwards Info on NUREG-0737,Item 2.F.1.4, Containment Pressure Monitor, Item 2.F.1.5, Containment Water Level Monitor & Item 2.F.1.6, Containment Hydrogen Monitor, in Response to NRC 830105 Request

ML20071D805
Person / Time
Site:	Peach Bottom
Issue date:	03/04/1983
From:	Daltroff S PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Stolz J Office of Nuclear Reactor Regulation
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.1, TASK-TM NUDOCS 8303110329
Download: ML20071D805 (15)

Text

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PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHIA. PA.19101 SHIELt>S L. DALT;40FF

.JM,!"/l5%o, March 4, 1983 Docket Nos. 50-277 50-278 Mr. V. F. Stolz, Chief Operating Reactors Branch #4 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555

SUBJECT:

NUREG-0737 Item 11.F.1.4 Containment Pressure Monitor Item II.F.1.5 Containment Water Level Monitor Ttem II.F.1.6 Containment Hydrogen Monitor RE: Peach Bottom Atomic Power Station

Dear Mr. Stolz:

The attachment to this letter provides the information on the NUREG-0737 requirements referenced above, as requested in your letter of January 5, 1993 (V. P. Stolz to E. G. Bauer, Jr.,

l PECo.). The information presented'in'the attachment is l designated with a numbering format that corresponds to your

! requests.

Should you have any questions regarding this matter, please j do not hesitate to contact us.

1 i

Sir.cerely, ll  ;

Z Jt[

Attachment /-

cc: Site Inspector l

C303110329 830304 I PDR ADOCK 05000277 l p PDR t

3

Docket Nos. 50-277 50-278 Attachment-

SUBJECT:

Request for Additional Information NUREG-0737. Items II.F.1.4, 5 and 6 Peach-Rottom Atomic Power Station Units 2 and 3 (1) Exceptions Being Taken To NUREG-07?7 Recuirements Request:

(la) Please indicat6 any exceptions that you plan to take to the NUREG-0737 itens in our scope of review. For each exception indicate (1) why you find it difficult to comply with this item, (?) how this exception will affect the monitor system accuracy, speed, dependahility, availa'oility, and utility, (3) if this exception in any way compromises the safety margin that the monitor is supposed to provide, and (4) any extenuating factors that make this exception less deleterious than it anpears at f ace value.

Response

( l a ') In addition to the exceptions described in items (3b) and (Ic) of the enclosure to your January 5, 1983 letter, we have taken the following exceptions to the NUREG-0737 requirements for containment pressure monitors, containment water level monitors, and containment hydrogen monitors. These exemption requests were previously identified in correspondence dated December 22, 1980 (S. L. Daltroff, PECo. to D.

G. Eisenhut).

1.) The design and qualification criteria for accident monitoring instrumentation (Appendix B of NUREG 0737) recommends physical separation in accordance with Regulatory Guide 1.75, rev. 2.

Peach Bottom was not designed and built to meet the separation criteria of Regulatory Guide 1.75, and back fitting the facility to this criteria is not practical. We have designed the accident monitoring instrumentation to the separation criteria applicable to the plant as described in the Peach Rottom Final Safety Analysis Report.

This exception does not affect the system's accuracy, speed, dependability, availability, or utility and does not compromise the safety margin that the instrumentaion is supposed to provide.

_.. )

Page 2 2.) The design and gaalification criteria for accident monitoring instrumentation (Appendix B of NURPG-0737) recommends environmental qualification in accordance with Regulatory Guide 1.89 (NUREG-0588). This requirement specifies qualification of new equipment to IEEE Std. 323-1974. The containment pressure transmitters are cualified to IEEE Std. 323-1471 since they were the best available equipment on the market at the time of their purchase. This exception will not affect the accuracy, speed, dependability, availability, or utility of the pressure monitoring system since these transmitters are essentially the same as transmitters from the same vendor that have since been quslified to IEEE 323-1974 requirements. In addition, the worst-case adverse environment at Peach Bottom is much less severe than the environment for which these transmitters have been qualified.

Therefore, this exception does not compromise the safety margin provided by this instrumentation.

3.) Miny of the rogulatory guides 21sted in Appendix B of NUREG-0737 pertainhtg to cuality assurance were not in existence at the time the Peach Bottom hydrogen analyzers were installed.

However, the analyzer system was specified, procurred, designed, fabricated, and installed in accordance with quality assurance programs which complied with the applicable portions of 10CFR50, Appendix B. Therefore, this exception does not affect the system's accuracy, speed, dependability, avai.1 ability, or etility and will not compromisa the safety margin that the monitor is supposed to provide.

Recuest:

(1b) In your letter of 22 Dec. 80 from Shields L. Daltroff (PECo) to Darrell G. Eisenhut (NRC), you state that your water level transducer range will extend to one foot above the bottoz of the suppression pool, rather than to the bottom as is required by NUREG-0737. You further state that you wish to take this exception so that you can use the existing water level transmitter rather than installing a new one. We find this exception to be acceptable, and will not require that you provide any further justification on this point.

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$ Page 3

Response

lb) No response required.

Recuest (Ic) In your letter of 23 Dec 81 from Shields L. Daltroff (PECo) to Darrell G. Eisenhut (NRC), you state that your hydrogen monitor has a 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> warmup period, whereas NUREG-0737 reauires that the hydrogen monitor be operation within one half hour after an accident.

Please state Nhat measures have been tried or are going to be tried to decrease the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> warmup period and state what progress, if any, has been made on this problem. You state that the long warmup time can be justified by the fact that you have an inerted containment. Are there any other extenuating factors that justify the long warmup time?

Response

Ic) As stated in correspondence dated December 23, 1981 (S. L. Daltroff, PECo to D. G. Eisenhut), the two hour warmup time of the hydrogen analyzers is sufficient for their intended use. Since the Peach Bottom containment is inerted and post-accident combustible gas control is maintained by oxygen deficiency, the control of combustible gas concentrations in containment is relatively insensitive to the rate or extent of hydrogen generation due to metal-water reaction. Maintenance of containment Qas concentrations below combustible limits is accomplished by the addition of nitrogen to limit oxygen concentration to less than 5%. Indication of hydrogen concentration is used only to determine if a level of hydrogen exists within containment such that control of oxygen concentration is needed. Based on Safety Guide No. 7 (now regulatory guide 1.7) assumptions, approximately one day will c-lapse af ter a loss of coolant accident before nitrogen addition is required. Recent evaluations submitted by the BWR Owners' Groups and reviewed by the NRC staff have demonstrated that the Regulatory Guide 1.7 radiolytic oxygen generation is extremely conservative. (Refer to letter number BWROG-8224 from T. J. Dente of the BWROG to D. G. Eisenhut of the NRC dated June 21, 1982, and the letter from W. G. Counsil of NUSCo to W.

J. Dircks of the NRC dated August 6, 1982.) Therefore, this exception to the NUREG-0737 requirements will not l

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Page 4 affect the hydrogen monitoring system's accuracy, speed,' dependability, availability, or utility in ,

performing its intended function. Furthermore, this exception does not compromise the safety margin that the monitor is supposed to provide.

! (2) II.F.1.4 - Containment Pressure Monitoring Syste9 Accuracy and Time Response.

Request (2a) Provide a block diagram of the configuration of

. modules that make up your PMS. Provide an explanation 4

of any details in the block diagram that might be necessary for an understanding of your PMS accuracy and time response.

Response

(2a) See figure 1 for a block diagram of the configuration of modules that make up the containment pressure monitoring system. There are four instrument loops, two with a range of O to 225 psig and two with a range of 5 to 25 psia. The power for the instrument loops l and the power to run the recorders is provided from

! the power supply through the power distribution

, mrdule.

i.

Request:

(2b) For each module provide a list of all parameters which describe the overall uncertainty in the transfer function of that module.

Response

[

(2b) The following parameters describe the overall uncertainty of the containment pressure monitoring system:

l Pressure transmitter (5 to 25 usia range)

Accuracy: + 8.3% (Includes combined effect of linearity,

hysteresis, and repeat-ability)

Seismic effect: + 0.83%

4'

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i Page 5 i

Temperature effect: 1 0.89% (for temperature change from 95 degrees F to 149 degrees F) 1 Power supply effect: negligable Deadband: none Stability: 1 0.42%

Pressure transmitter (O to 225 psig range) i Accuracy: i 7.4% (Includes combined j effect of linearity, hysteresis, and repeat-ability)

Seismic effect: + 0.74%

Temperature effect: } 1.0% (for temperature change from 85 degrees F to 149 degrees F)

Power supply effect: negligable Deadband: none Stability: 1 0.37%

Current to Volimge Converter Accuracy: + 0.17%

Power Supply Effect: + 0.016%

Ambient Temp. Effect: [ O.17% (for temperature change from 70 degrees F to 120 degrees F)

Relative Humidity Effect: + 0.17%

Seismic Effect: 7 0.17%

Recorder (recording function)

Accuracy: + 0.25%

Repeatability: 0.1%

Ambient Temp. Effect: < 0.25% (for temperature change from 70 degrees F to 120 degree 9 F)

Relative Humidity Effect: +0.25%, -0.5%

Power Supply Effect: < 0.009%

Recorder (indicating function)

Accuracy: + 0.17%

Repeatability: 5.13 Ambient Temp. Effect: 0.25% (for temperature change from 70 degrees F to 120 degrees F)

Relative Humidity Effect: + 0.17%

Power Supply Effect: 5.009%

NOTE: The above values are expressed as a percentage of full calibrated range.

Page 6 Recuest:

(2c) Combine parameters in 2b to get an overall system uncertainty. If you have both strip chart recorder and indicator output, give the overall system uncertainty for both systems. If you have systems spanning difi;erent ranqes, give the overall system uncertainty for each system.

Response

(2c) The following is the overall system uncertainty:

+7.55% for 0 to 225 psig recorder T7.53% for O to 225 psig indicator T8.43% for 5 to 25 psia recorder IR.41% for 5 to 25 psia indicator Recuest:

(2d) For each module indicate the time response. For modules with a linear transfer function, state either the time constant,)* , or the Ramp Asymptotic Delay Time, RADT. For modules with an output that varies linearly in time, state the full scale response time.

(Most likely the only module you have in this category is the strip chart recorder.)

Response

(2d) The following is the response time for each module:

Transmitter - time constant is 0.2 seconds.

Current to Voltage Converter - when excited by an 90%

input step from 10 to 90%, the maximum time required for the output of steady state value is 37 milliseconds nominal and 50 milliseconds maximum.

Recorder - 3.5 seconds to travel from 10 to 90% of the scale.

(3) II.F.1.5 - Containment Water Level Monitoring System Accuracy Recuest (3a) Provide a block diagram of the configuration of ,

modules that make up your WLMS. Provide an explanation of any detalles in the block diagram that

5 I Page 7 might be necessary for an understanding of your WLMS accuracy.

Response

(3a) See figure 2 for a block diagram of the configuration of modules that make up the suppression pool water l 1evel monitoring system. There are two suppression j pool wate: level instrument loops, each with a range of 1 foot to 21 feet from the bottom of the suppression pool. The power for the instrument loops and the power to run the recorde s is provided from the power supply through the power distribution module.

Request:

(3b) For each module provide a list of all narameters which describe the overall uncertainty in the transfer function of that module.

Response

(3b) The following parameters describe the overall uncertainty of the suppression pool water level monitoring system:

Response

Level Transmitter Safety Function Performance: + 3.3% (includes combined effect of non-linearity, deadband, hysteresis, and repeat-ability and the accumu-lative effects of temp.,

radiation, seismic, and LOCA)

Power Supply Effect: + 0.003%

Current to Voltage Converter Accuracy: + 0.17%

Power Supply Effect: T O.016%

Ambient Temp. Effect: I O.17% (for temperature l

change from 70 degrees F to 120 degrees F)

Relative Mumidity Effect: + 0.17%

Seismic Effect: 7 0.17%

Recorder (recording function)

Accuracy: + 0.25%

Page 8 Repeatability: 0.1%

Ambient Temp. Effect: < 0.25% (for temperature

, change from 70 degrees F to 120 degrees F)

Relative Humidity Effect: +0.25%, -0.5%

Power Supply Effect: < 0.009%

Recorder (indicating function)

Accuracy: + 0.17%

Repeatability: 0.1%

Ambient Temp. Effect: 0.25% (for temperature change from 70 degrees F to 120 degrees F)

Relative Humidity Effect: + 0.17%

Power Supply Effect: 5.009%

Indicator Accuracy: + 0.5%

Hysteresis: T 0.67%

NOTE: The above values are expressed as a percentage of full calibrated range.

Request:

(3c) Combine parameters in 3b to get an overall system uncertainty. If you have both stripchart recorder and indicator output, give the overall system uncertainty for both systems. If you have systems spanning different ranges, give the overall system uncertainty for each system.

Response

(3c) The following is the overall system uncertainty:

+3.40% for the recorder

~+3.37% for the indicator on the recorder

+3.45% for the separate indicator (4) II.F.1.6 - Containment Hydrogen Monitoring System Accuracy and Placement Recuesti j (4a) Provide a block diagram of the configuration of modules that make up your HMS. Provide an explanation of any details in the block diagram that might be necessary for an understanding of your HMS accuracy. '

Page 9 If you have different types of HMSF give this information for each type.

Response

(4a) See figure 3, for a block diagram of the configuration of modules that make up the containment hydrogen monitoring system. There are four instrument loops, each with a range of O to 20%. Two loops monitor hydrogen in the suppression pool airspace and two loops monitor hydrogen in the drywell atmosphere.

Recuest:

(4b) For each module provide a list of all parameters which describe the overall uncertainty in the transfer function of that module.

Resoonse:

(4b) The following parameters describe the overall uncertainty of the containment hydrogen monitoring system:

Hydrogen Analyzer Accuracy of Analyzer: + 1.0% (unadjusted for moisture or steam dilution within the containment)

Temperatute Effect: none Flow Measurement Effect: none Power Supply Effect: none Deadband: none Hysteresis: none Recorder Accuracy: + 0.17%

Deadband: 0.083%

Indicator Accuracy: + 0.5%

Hysteresis:

[ 0.67%

Request (4c) Combine the parameters in 4b to get an overall system uncertainty. If you have both strip chart recorder

Page 10 and indicator output, give the c-rerall system uncertainty for both systems.

Response

(4c) The following is the overall system uncertainty:

+ 1.0% for the recorder

} 1.3% for the indicator Recuest:

(4d) Indicate the placement and number of hydrogen monitor intake ports in containment. Indicate any special sampling technioues that are used either to examine one region of containment or to assure that a good cross section of containment is being monitored.

Response

(4d) Redundant analyzers are provided to monitor hydrogen concentration in each drywell and torus. Samples are withdrawn through primary containment penetrations at the following elevations:

drywell: El. 127'-2" drywell: El. 199'-9" torus: El. 125'-0" torus: El. 114'-0" Since the primary containment is not compartmentalized, except into drywell and torus, multiple sample points within the containment compartments for each analyzer are not considered necessary. An analysis of the effectiveness of combustible gas mixing within the PBAPS primary containment is included in FSAR Supplement I, Response to Question 14.6.

Recuest:

(4e) Are there any obstructions which would prevent hydrogen escaping from the core from reaching the hydrogen sample ports ouickly?

Page 11

Response

(4e) There are no single obstructions which can prevent hydrogen escaping from the core from reaching the hydrogen sample ports quickly. Redundant sample lines are provided to ensure that blockage of-a single line will not prevent the analysis of containment gas from either the drywell or the suppression pool airspace.

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