ML20065E139

Safety Evaluation Supporting Amend 169 to License DPR-49

ML20065E139
Person / Time
Site:	Duane Arnold
Issue date:	09/19/1990
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20065E133	List: ML20065E132 ML20065E139
References
GL-88-01, GL-88-1, NUDOCS 9010010321
Download: ML20065E139 (4)

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SAFETY EVALUATION BY-THE OFFICE OF NUCLEAR REACTOR REGULAT!0N l

R_ ELATED TO AMENDMENT NO.169 TO FACILITY OPERATING LICENSE NO. DPR-47 v

IOWA ELECTUC LIGHT AKD F0WER COMPANY 7NRAL IL,'4A POWER C00PERATI(E

~ Eb?N BELT' POWER COOPERATIVE DUANE ARNOLD ENERGY CENTER i

DOCKET NO. 50-331 l

1.0 INTRODUCTION

By letter dated Jut. 27, 1988, Iowa Electric Light and Power Company (the licensee) requested changes to the Duane Arnold Energy Center (DAEC) Technical Specifications (TSs). The Generic Letter (GL) 88-01, groposed changes were submitted in response to NRC 4

NRC Position on IGSCC in.BWR Austenitic Stainless i

Steel Piping," and its enclosure, NUREG-0313, Revision 2,'"Te::hnical' Report on -

Material Selection and Processing Guidelines for BWR Coolant Pressure 8oundary Piping."

E The NRC staff approved the licensee's proposed inspection program and response

to GL 88-01 in a letter dated May 31, 1990. That letter did not address the" a

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proposed TS changes that are reviewed in this~ Safety Evaluation, except' to identify that; the licensee's proposed. frequency of monitoring: reactor coolant-system (RCS) leakage:once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> was unacceptable. The May 31, 1990-4 letter also described a' change in the NRC sta_ff position regarding the frequency.

-of leakage monitoring. The staff' position in GL 88-01~ had specified that leakage monitoring of sump ~. levels using fixed-measurement-interval methods should be conducted at 4-hour intervals or'less. The staff has subsequently relaxed the specified frequency to_ once every 8' hours, due to the unnecessary administrative L

hardship; imposed by the 4-hour-interval. The licensee revised its request of F

July 27.- 1988.by letter dated June 29, 1990, to conform with the staff's current position on RCS leakage monitoring.

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The proposed changes clerify Table 3.2-E, " Instrumentation. that Monitors Drywell-3 Leak Detection," revise TSs 3.6.C and 4.6.C, and add TS 4.6.G.3 to conform with 4

the staff positions.of GL 88-01, as revised.

In addition, the proposed changes i

revise TSs 4.6.G.I.a and 14.6 G.2.a to specify the be9innin 10-year inservice inspection (ISI) and inservice testing (g dates for the second-IST) programs. TS 4.6.G.3 is deleted, as the first 10' year ISI-and IST intervals have been completed, and TS 4.6.G.4 is'also deleted, as the interim ISI program for the recirculation system inlet nozzle safe-ends has been completed and future inspevions will be included;in'the scope of the GL.88-01 program. The associated Bases for the TSs are also revised.to reflect the proposed changes.

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!f d' 2.0 EVALUATION s

The' licensee has poposed revisions ~ to Table 3.2-E, " Instrumentation that Monitors Drywell Leak Detection," and to TS 3.6.C.2, to clarify the oper-ability requirements for those systems used for drywell leak detection.

L The licensee provided additional information.on these systems in a letter dated April 24, 1939.

The primary system used for the detection of drywell leakage 'at the DAEC is the Sump system, consisting of the Equipment Drain Sump subsystem and the 4

L Floor Drain Sump subsystem.

Each subsystem is comprised of a flow integra-3 p

tor, a sump pump run timer, and a sump fill timer.

Each of these devices L

can be used by plant operators to calet ' ate drywell leakage rates. The flow' m

integrators receive' signals from flow transmitters located in_the discharge

' piping of both sumps, and calculate the total amount of fluid discharged.

from each sump.

This information is used by the operators to calculate the drywell leakage rates and record them at 4-hour intervals in accordance with plant procedures. The two sump ) ump run timers measure the _ length of time -

La each pump runs, from the point tlat a high sump level starts the pump, until L

it shuts off automatically upon reaching the low level setpoint.

For a given pump flow rate, the time the pump is running corresponds.to a set drywell leakage rate.

Therefore, if the pump is running for too long, a high i

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drywell leakage rate is indicated in the control room. The sump fill timers.

I measure the time between successive pump starts.

These timers are set to correspond to the time period between pump starts for an established pump flow' rate and specified-drywell leakage rate.

If the pump restarts prior to-reaching the set time interval, then drywell leakage is greater than the i

setpoint and an annunciator is activated in the control room.

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Any one of these six instruments is sufficient to detect increased drywell-leakage.

Identified leakage, which is composed of normal seal and valve L

packing leakage, is collected in the Equipment Drain Sump, while unidenti--

fied ;1eakage, composed of all other leakage from the reactor primary system, 1

is collected in the Floor Drain Sump. The two sumps are adjacent to each l

other,: located beneath the. reactor, inside the reactor vessel' pedestal.

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all' three leak detection instruments in one sump were inoperable, the pumps in that sump would not start' automatically and the sump would eventually overflow into the aojacent sump. Based on the 850-gallon capacity of each sump (and the 200 gallon low-level setpoint), at a drywell leakage rate of 5 gpm, one sump would begin to overflow to the other'.in just over'2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. At-

- a' leakage rate of 2 gpm, the time would be roughly Si hours.

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The~ Floor Drain Sump instrumentation is set to detect unidentified drywell

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leakage, while the Equipment Drain Sump instrumentation is set to detect

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identified leakage, in the event that all three _ Floor Drain sump components l

are inoperable, the Equipment Drain Sump timers would be recalibrated to L

the lower setpoint for detection of identified leakage Therefore, if any L

ole of the six instruments of the Sump system was operable, plant operators could-detect high drywell leakage and take appropriate actions in?a reason-able amount of time.

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Tne Mr Sampling System provides backup capability to detect drywell leakage,

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by monitoring increases-in the radioactivity in the drywell atmosphere.-

However, this system 'is not _ capable of quantifying drywell leakage and is therefore only intended to be used when the Sump system is inoperable, s

Proposed TS 3.6.C.2 specifies that the Sump' system shall be operable any tine irradiated fuel is in the vessel and reactor coolant temperature _ is.

above 212'F. If the Sump system is inoperable, continued reactor operation is permissible for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> only if the Air Sampling-System is operable;-

otherwise, the reactor shall be in the Cold Shutdown Condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. This revised specification has a 24-hour limiting condition for operation (LCO) instead of the current 7-day LC0;~however, the current LCO requires thatLthe Air Sampling System be operable in addition to the Sump system.

The NRC staff 'inds;that the revised Table 3.2-E and revised TS 3.6.C.2 more accurately reflect the redundant design of the DAEC Sump system drywell

-leakage monitoring instrumentation and the. backup function of'the Air Sampling System, thereby providing more appropriate requirements for drywell:

leak detection ~.

The Bases of pages 3.2-45 and 3.6-26 have also been revised to reflect these changes, which the staff finds acceptable.

Proposed TS 3.6.C.1 and 4.6.C.1 and 2 have been ravised consistent with 'the staff's position in GL 88-01, as modified, in part,.in the May 31, 1990 NRC letter to the licensee.

TS 3.6.C.1.b adds a limit of 2 gpm. increase in unidentifed leakage within a 24-hour period.

If this additional limit is exceeded,- the reactor shall be in a Cold Shutdown Condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, as required by TS 3.6.C.3.

As a point of clarification,.if a'2 gpm increase in' unidentified 'Takage was observed in less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />,.the limit would also be considered to be-exceeded and the appropriate action required, consistent with the wording tf GL 88-01.

The revised Bases of page 3.6-25 provide additional clarification.

Surveillance Requirements (SRs) 4.6.C.1 and-2. require the RCS ' leakage to be checked by the sump system and recorded once every 8-hours and the Air Sampling system to be checked and recorded once every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. These revised TSs are consistent with the current staff positions as described in GL 88-01 and the May 31, 1990 NRC letter; there-fore they are acceptable.

SR 4.6.0.1 is revised to delete a footnote referring to a previous change.

Deletion of the footnote is an editorial change that clarifies the require-ment and is therefore acceptable.

R Proposed SRs 4.6.G.1.a and 4.6.G.2.a and the associated Bases specify the starting dates for tne second 10-year intervals for the ISI and IST-programs, respectively. Also, SR 4.6.G.3. is deleted, removing extraneous;information-

-regarding the completed first 10-year intervals. These sections are added or deleted for clarification and do not alter any existing requirements; therefore, the staff finds these changes acceptable.

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j A new Surveillance Requirement 4.6.G.3 is proposed, in which the licensee i

commits to perform an inservice inspection-program for piping identified in NRC GL 88-01, in accordance with the staff positions contained therein.- The proposed SR is worded exactly the same as the sample specification provided iin GL 88-01. Therefore, the staff finds the proposed SR acceptable.

Finally, SR 4.6.G.4 is deleted to remove the references to the interim testing program for the recirculation system inlet. nozzle safe-ends.

Ins section of these_ components will be continued at the same frequency wit 11n.the scope of the' licensee's GL 88-01 inspection r agram, as required-by SR 4.6.G.3.

Therefore, the deletion of SR 4.6.5.4 :.oes not alter existing requirements and is acceptable to i.he st;/f.

ol' In summary, the proposed TS changes e aform with the staff positions of GL 88-01, as they commit the licensee to conduct an approved inservice inspec-tion program for piping susceptible to intergranular stress corrosion.

l cracking. The licensee's GL 88-01 inspection program for the DAEC was-previously approved by the staff in a letter dated May 31,'1990.

I 3.0- ENVIRONMENTAL CONSIDERATION This amendment involves a change to a requirement with respect to the installation or use of a facility component located within the restricted

-area as defined in 10 CFR Part 20 or a change to a surveillance requirement.

The staff has determined that the amendment involves no significant increase l

in the amounts, and no significant change in the types, of any effluents -

that may be released offsite and that there is no significant increase in; individual-or cumulative occupational radiation exposure. The Commission has -previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comr.unt on l-such finding. Accordingly,: this amendment meets the eligibility criteria forcategoricalexclusionsetforthin10CFR:51'.22(c)(9). This amendment I

also involves changes in recordkeeping, reportiics or administrative pro-L cedures or requirements. Accordingly, with respect to these items, the i

amendments meet-the eligibility criteria for categorical exclusion set forth L

in10CFR651.22(c)(10). Pursuantto10CFR51.22(b),.noenvironmental i

impact statement or environ:nental assessment need be prepared in connection

.with the issuance of this amendment.

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4.0 CONCLUSION

The staff has concluded, based on the considerations discussed above, that:

'(1)'there. is reasonable assurance that the health and safety of the public will not be endangered by operation in tne propm ed manner, and (2) such~

activities will be conducted in compliance with the Commission's regula-tions, and the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor: James R. Hall, NRR Dated: September 19, 1990

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