ML20115B388

Proposed TS Sections 2.10.4(5)(a)(i) Re DNBR Margin During Power Operation Above 15% of Rated Power & 3.2 Re Equipment & Sampling Tests

ML20115B388
Person / Time
Site:	Fort Calhoun
Issue date:	10/09/1992
From:	OMAHA PUBLIC POWER DISTRICT
To:
Shared Package
ML20115B375	List: ML20115B368 ML20115B386 ML20115B388
References
NUDOCS 9210160026
Download: ML20115B388 (10)

Text

e 2.0 LIMrtTNG CONDITIONS FOR OPERATION 2,10 Reactor Cort (Continued) 2.10.4 Power Distribution Limits (Continued)

(5) DNBR Marcin During Power Ooemtion Above 15% of Rated Power l

(a)

The following DNB related parameters shall be maintained within the limits, shown:

(i)

Cold Leg Temperature (1)h bN l

(ii)

Pressurizer Pressure 12075 psia *

(iii)

Reactor Coolant Flow 1197,000 pm" 3

(iv)

Axial Shape Index, Yi (2) l 6

(b)

With any of the above parameters exceeding the limit, restore the parameter to within its limit within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or reduce power to less than 15 % of rated power witnin the next 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

B241

'Dr. limitation ca linear heat rate ensums that in the event of a LOCA, the peak temperature of the fuel cladding will not exceed 2200'F.

Eit

, of the two core power distribution monitoring systems, the Excore Detector Monitoring System, or the Incore Detector Monitoring System, provide adequate mortitorin;; of the core power distribution and are capable of verifying that the linear heat rate does not ex'.:eed its limit. The Excore Detector Monitoring System performs this function by continuously monitoring the axial shape index with the operable quadrant symmetrie excore neutron flux detectors and verifyinF that the axial shape index is maintained within the allowable limits of the Limiting Condition for Operation for Excore Monitoring of LHR Figure provided in the COLR as adjusted by Specification 2.10.4(1)(c) for the allowed linear heat rate of the Allowable Peak Linear Heat Rate vs. Burnup Figure provided in the COLR, RC Pump configuration, and F,7 of the Fa, p r and Core Power r

Limitations Figure provided in the COLR. In conjunction with the use of the excore monitoring m

system and in establishing the axial shape index limits, the following assumptions are made:-(1) the CEA insertion limits of Specification 2.10.1(6) and-long term insertion limits of Specification 2.10.1(7) are satisfied, (2) the flux peaking augmentation factors are as shown in Figure 2-8, and (3) the total planar radial peaking factor does not exceed the limits of Specification 2.10.4(3).

Limit not applicable during either a thermal power ramp in excess of 5% of rated thermal power per minute or a thermal power step of greater than 10% of rated thermal power.

• • This number is an actual limit and corresponds to an indicated flow te of 202,500 gpm. All other values in this listing are indicated values and include a ce for measurement uncertainty (e.g.,543'F, indicated, allows for an actual T, of 54 'F)

(1) Within the limit for Core Inlet Temperature provided in the COLR.

(2) Within the Limiting Condition for Operation for DNB Monitoring Figure provided in the COLR.

9210160026 921009 2-57c Amendment No. 3G, G,H.70 PDR ADOCK 05000285 P

PDR W,93,10^,il7,141

- -.~._ --.

(Continced)

Test QSA p( -

FreQumcv 4 EAR-Sectico Refemce

'10b.

Charcoal adsorbers ol.

In-Place Testim **

Each refueling shutdown not to ex ed 6.2 for Spent Fuel Onrcoal adsorbers shall be 18 months or af ter every 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> 9.10

'y Storage Ibcl Arm leak.testal and shall show of systm operaticm, or af ter each 2 99% Freon (H-ll or R-ll2) corplete or partial replacment of the ruroval.

charcoal adsorber bank, or after any major structural maintmance on the a

systm housirg and following significant.

painting, fire or.chmical release in a

.. i ventilation zone cremunicating with tle '

systs.

2.

Iaboratory Testim

a. Initial f :tch tests of.all Prior to initial loading in the filter unit.

charcoal adsorixrs shal1 show 2 99% elmental iodine renoval U

when tested under conditicns

-of295gR.li.,2: 125"F, - 5 to.'

10 mg/m inlet elm ental iodine concentration and at the

'7 fa ' velocity wi&in + 20%.of

'g systan design.-

tr -

b.1he carbon sanple test results shallishaw 2 90%

^.Each refueling. shutdown-not to exceed'18 aanths or after every 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> of systm elenental.-iodine rmoval, under cxn11tions of 2 95 g0 operation, and following significanc painting,: fire or chmical release in any RJI., 2 125'F,. S ' ic 10 tone comunicating with the systm.

' inlet elemental concentratica and within ~20% of design face velocity..

3.

Overall Systen Operation -

a.- Operation of mch circuit -

Ten umrs'every nonth shall be dmonstrated.

s

'b. Volme flow rate through ~

. At least once per plant operating cycle.

charcoal f11ter shal1~be shown

~

to be between-909%and 12,000 cin.

~'i600 4L Manual initiation of the At' least cr.ce per plant operating cycle.

system shall be daronstrated.

• • Tests shall be perfooned in accordance with applicable section(s) of ANSI NS10-1990..

Amendment No..15. ' 28;. 52

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4 3

2.0 '

LIMIIIRQCONDITIONS FOR OPERATION Reactor Core (Continued)

'2.10 2.10,4 Power Distribution Limits (Continued)

(5) DNBR Margin During Power Ooeration Above 15% of Rated Power (a)

The following DNB related parameters shall be maintained within the limits, shown:

(i)

Cold Leg Temperature (1) l (ii)

Pressurizer Pressure 12075 psia *

(iii)

Reactor Coolant Flow A197,000 gpm" (iv)

Axial Shape Index, Yi (2)

(b)

With any of the above parameters exceeding the limit, restore the parameter to within its limit within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or reduce power to less than 15% of rated power within the next j

8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

Elli.h The limitation on linear heat rate ensures that in the event of a LOCA, the peak temperature of the fuel cladding will not exceed 2200*F.

Either of the two core power distribution monitoring systems, the Excore Detector Monitoring System, or the incore Detector Monitoring System, provide adequate monitoring of the core power distribution 4

and are capable of verifying that the linear heat rate does not exceed its limit. The Excore Detector Monitoring System performs this function by continuously monitoring the axial shape index with the operable quadrant symmetric excore neutron flux detectors and verifying that the axial shape index 4

is maintained within the allowable limits of the Limiti,, Condition for Operation for Excore Monitoring of LHR Figure provided in the COLR as adjusted by Specification 2.10.4(1)(c) for the allowed linear heat rate of the Allowable Peak Linear Heat Rate vs. Burnup Figure provided in tie T

T T

COLR, RC Pump configuration, and F,y of the Fg, by and Core Power Limitations Figure provided in the COLR. In conjunction with the use of the excore monitoring system and in establishing the axial shape index limits, the following assumptions are made: (1) the CEA insertion limits of Specification 2.10.l(6) and long term insertion limits of Specification 2.10.l(7) are satisfied, (2) the flux peaking augmentation factors are as shown in Figure 2-8, and (3) the total planar radial peaking -

factor does not exceed the lir% of Specification 2.10.4(3).

Limit not applicable during either a thermal power ramp in excess of 5 % of rated thermal power per minute or a thermal power step of greater than 10% of rated thermal power.

This number is an actual limit and corresponds to an indicated flow rate of 202,500 gpm. All other values in this listing are indicated values and include an allowance for measurement uncertainty (e.g.,543'F, indicated, allows for an actual T, of 545 F).

l_

(1) Within the limit for Core inlet Temperature provided in the COLR.

(2) Within the Limiting Condition for Operation for DNB Monitoring Figure provided in the COLR.

2-57c Anv ndment No. 32,43,5-7,-70, W,92,409,M7,M1,

TABLE 3-5 (Continued)

.USAR

-l Test Freouency Sectica Refererice s

10b.

Charcoal Adsorbers 1.

in-Place Testine**

Each refueling sh'ndown not to exceed 18 months or 6.2 -

for Spent Fuel Charcoal adsorbers shall be after every 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> of system operation, or after 9.10 Storage Pool Area leak tested and shall show each complete or partial replacement of the charcoal

~

199% Freon (R-1i er R-112) adsorber bank, or after any major structural maintenance removal.

on the system housing and following significant painting, fire or chemical release in a ventilation zone communicating with the system.

2.

Laboratory Testine

a. Initial batch tests of all Prior to initial loading in the filter unit.

charcoal adsorbers shall show 199% elemental iodine removal when tested under conditions of195% R.H.,1125'F. 5 to 2

10mg/m inlet elemental iodine concentration and at the face velocity within 120% of system design.

b. The carbon sample test Each refueling shut < lown not to exceed 18 results shall show 190%

months or after every 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> of system.

elemental iodine removal, operation, and following significant tu. der conditas ofl95%

painting, fire or chemical release in any R.H.,1125'F,5 to 10mg/n/

ventilation zone communicating with the system.

l inlet elemental concentration and within 20% of design face velocity.

3.

Overall System Operation

a. Operation of each circuit Ten hours every month.

shall be der.onstrated.

b. Volume flow rate throug'n At least once per plant operating cycle.

charcoal filter shall be shown to be between 4500 and 12,000 l

cfm.

4.

Manualinitiationof the At least once per plant operating cycle.

system shall be denwnstrated.

CCTests shall be performed in accordance with applicable section(s) of ANSI N510-1980.

3-20b Amendment No. 45,34.52,438,

U.S. Nuclear Regulatory Comission LIC-92-210A ATTACHMENT B 4

i

DISCUSSION, JUSTIFICATION AND NO SIGNIFICANT HAZARDS CONSIDERATION ANALYSIS DISCUSSION AND JUSTIFICATION OF ANENDMENT REQUEST:

Omaha Put.lic Power District is proposing to modify Fort Calhoun Station Unit No.

1 Technical Specifications 2.10.4 Power Distribution Limits" and 3.2, " Equipment and Sampling Tests."

The proposed revision to Technical Specification 2.10.4 e.etablishes a limit for Cold leg Temperature, to maintain DNBR Margin during power o)eration above 15%

of rated power. Ite current Technical Specification wording d' d not require Cold Leg lemperature to be less than or equal to the Core Operating Limits Report (COLR) limit during either a therol power ramp in excess of 5% of rated thermal power per minute or a thermal power step of greater than 10% of rated thermal power.

The proposed wording it more conservative and does not permit the temperature to exceed the COLR limit during any thermal pcwer ramp or step conditions. This was established to be the most conservative mode of operation per the Core Operating Limits Report.

This change to Technical Specification 2.10.4 is submitted to be consistent with the Core Operating Limits Reprt which was approved in Amendment No. 141.

The proposed revision to Technical Specification 3.2 (Table 3-5) LPis result of the changes which were made to the Fort Calhoun Station Unit No.1 ated Safety Analysis Report (USAR), Section 14.18, Fuel HandlinOPPD : submitted a revised USAR Sect Accident-NRC on July 9, 1991 (Letter LIC-91-185R) which was accepted by the N C in a letter dated August 14, 1991.

The revised FHA analysis did not credit removal of any radioiodine gases through operation of the Spent fuel Pool Charcoal Filter (VA-66).

In current Technical Specifications (Table 3-5), the charcoal filter of the Spent Fuel Storage Pool Area (VA-66) is required to be tested for overall system operation. At least once per plant operating cycle a specified volunetric flow rate shall be passed through the VA-66 charcoal filter. The current Technical Specifications require a charcoal filter volumetric flow rate between 9,000 and 12,000 cfm. The propos3d amendment will modify the required volumetric flow rate to between 4,500 and 12,000 cfm. The original design basis for VA-66 indicated that the unit was designed for a rated air flow of 12,000 cfm per manufacturer's drawings. The minimum flowrate was established to be consistent with operating modes of the fans.

The change being proposed for Technical Specification 3.2 (Table 3-5) is based upon recent test data.

In order to assess the quantity of gas released over the spent fuel pool which passes through VA-66, an; ensure that a fuel handling related radioactive gas relear,e could be at least partially contained / controlled in the Auxiliary Building, a series of tracer gas tests were performed to-establish operational configurations.

The purpose of the testing was to demonstrate that General Design Criterion (GDC)d that VA-66 would mitigate the consequences of a fuel 19 r operation of VA-66 an handling accident.

The tracer gas tests proved control of gaseous releases in accordance with GDC-19.

The original design flowrates based upon operating two intake and three exhaust fans.(9,000-12,000 cfm) were During the tracer gas tests, operation of two intake and three exhaust fans was found to cause flow instability in the exhaust fan plenum. The most effective flow throu obtained with a system operation of one intake and two exhaust fans.gh VA-66 was Therefore, a higher level of control was established by using one intake fan and two exhaust fans, which corresponds to operation within the range cf 4,500-12,000 cfm.

1

4 4

4 The procedures and a summary of results for the tracer gas testing were provided to the NRC in OPPD letter LIC-91-185R, dated July 9,1991. It was concluded that VA-66 could not pass flow rates approaching 42 OM cfm and meet stability cfm. ptimal flow rate for VA-66 stability was found to be between criteria.

The o 4,000-5,000 This flow rate was found to be substantially below the lower limit of the Technical Specification 3.2 Table 3-5 value. This discrepancy in operational design flow rate is not a-significant hazard since-the revised USAR Section 14.18 analysis does not credit VA-66 to mitigate radiological-consequences, even though actual tests have demonstrated the effectiveness of VA-66 to contribute to the reduction of radiation doses.

NRC approval, in the August 14, 1991 letter from T. R. Quay )to W. G. Gates (OPPD)for justification of of the revised FHA analysis (as-built VA-66 configuration provides-the basis lowering the surveillance testing flow rate requirement.-

In conclusion, it has been demonstrated that VA-66 is not required to operate during fuel handling for offsite radiological consequences to be."well within 10 CFR Part 100 limits criteria as specified in the Standard Review Plan should a FHA occur.

However, mitigation of radiological consequences is recognized through operation of VA-66 at a flow rate of 4,500-12,000 cfm. As a result of tracer gas testing it has been concluded that approximately 40% of the -

radiciodines can be removed by VA-66 through optimal flow configurations of 4,000-5,000 cfm.

Administrative Chances 1.

A parenthesis is being added to note ** on the bottom of page 2-57c to enclose the parenthe+,ic expression contained in that note.

2.

The column of Table 3-5 titled FSAR Section Reference is being revised to reflect the current nomenclature for the FSAR which is the USAR (Updated Safety Analysis Report).

3.

Item 10b.2.b. on Table 3-5 is being revis'ed to correct a typographical 2

error.

The phrase . 5 to 10 m/m inlet elemental concentration..." is being corrected to ". 5 to 10 mg/m' inlet elemental concentration.."

consistent with Amer.dment-52. This typographical error was inadvertantly incoporated into Table 3-5 in Amendment 128.

4 4

1 2

t BASIS FOR NO SIGNIFICANT n ZARDS DETERNINATION:

i -

A no significant hazards determination is made for each proposed Technical Specification revision as discussed below, i

Proposed Technical Specification 2.10.4 Revision:

4 The proposed change does not involve a significant hazards consideration because operation of the Fort' Calhoun Station Unit No.- 1 in accordance with thO change would not:

(1)

Involve a significant increasa in the probability or consequences of_-an accident previously evaluated.

i Tha change being made to' the applicable allowance of the Cold Leg Temperature DNBR limit during power o)eration above 15% of rated power is conservatively being removed and will not increase the probability -or i

consequences of an accident previously evaluated, since Fort Calhoun 1

Station procedures and setpoints do not permit a Cold Leg Temperature---

greater than the existing lirit for excaption conditions which are currently stated in the Technical Specificatir. A Cold Leg Temperature limit less than or equal to the existing-Tecanical Specification /COLR 4

limits for a'l thermal -)ower ram ing or stepping conditions results in a more conservative trans'ent anal sis. Assuming a more conservative input 4 _

to the DNBR Margin transient ana ysis, ensures that the consequences of an accident previously aaalyzed will not increase.

The revised Technical Specification chang /setpoints as well as the Core Operating Limits Report.e is b existing procedures i

(2)

Create the possibility of -a new or_ different-kind of accident from.any previously analyzed.

4 It has been determined that a new or different kind of accident will not be possible due to this chanc e.

0)eration with a DNB limit on Cold Leg Temperature to be maintained less t1an or equal to the existing Technical Specification 2.10.4(5)(a)(fferent type of accident, since the limit can i) limit without exception does not create the possibility of a new or di not be exceeded during thermal power ramps or steps. - With res)ect to DNBR i

Margin it was found to be more conservative to maintain-tie Cold Leg Temperature limit within the specified limit.

(3)

Involve a significant reduction in a margin of safety.;

In conjunction with the USAR transient analysis it was determined that the margin of safety as currently specified in the Technical Specifications would not be reduced by this change.

Therefore, based on conservatively maintaining the existing Cold leg Temperature limit without exception, OFvD has determined that'this change does not involve a significant hazards consideration as defined in 10 CFR 50.92.

The proposed change will not result in a condition which significantly e'ters the: impact-of the station on the environment. Thus, the pro)osed change muts the eligibility criteria-for categorical exclusion set.forth in 10 CFR 51.22(c)(9) and pursuant to 10 CFR _51.22(b) no environmental assessment need be prepared.

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Proposed Technical specification 3.2 Revision:

1he proposed change does not involve a significant hazards consideration because operation of the fort Calhoun Station Unit No.1 in accordance with this change would not:

(1)

Involve a significant increase in the probability or consequences of an accident previously evaluated.

The fuel handling accident analysis documented in Section 14.1B of the USAR indicates that operation of VA 66 was not credited to calculate the dose consequences for this accident condition.

The FHA dose analysis conservatively assumes no operation of VA 66.

Although VA 66 is not credited for removal on radiolodine following a FHA,l testing of VA 66 the unit will be maintained and tested. The OPPD analysis and functiona for radiciodine removal following a FHA was reviewed by the NRC as documented in the August 14, 1991 letter to OPPD TAC No. 80635).

testing and maintenance of VA 66 also is p(rudent for ALARA Operation reasonswIthinthespentfuelpoolareaduringfuelhandling.

The proposed Ennical Specification change will apply new -testing requirements which satisfy the optimal operating configuration for VA-66 to provide mitigation of a FHA. Therefore, this change does not increase the probability a consequences cf an accident since VA 66 will continue to be maintaine with optimal flowrates even though it is no lon credited in the USAR Section 14.18 radiological consequences analysis.ger

- A change in testin requirements does not impact the ast.umptions made in the revised FHA anal sis.

(2)

Create the possibility of a new or different kind of accident from any previously analyzed.

It has been determined that a new or different kind of accident will not be possible due to in:s change. The reduction of operational surveillance testing flow rate requirements for VA-66 does not create the possibility of a new or different kind of accident, since the component is no longer credited in the USAR-for o)erability.- Reducing the-flow rate tpecified in surveillance testing main;ains the optimum flow configuration.--

o (3)

Involve a significant red 9ction in a margin of safety.

Reduction of the o >erational surveillance testing - volumetr..: flow rate requirement will norreduce the margin of safety since VA 66 is maintained operable at a flowrate of 4,500-12,000 cfm.

In accordance with Section 14.18 of the USAR, VA 66 is no lohger credited for mitigating radiological consequences-as a result of a FHA.-' The revised radiological FHA analysis is based conservatively on approved '/Q values and dsontamination factors.

The NRC concluded in a letter to-0 PPD dated-August 14, 1991-that the as-built conditions of VA 66 ~ are. acceptable.

The optimum filtering configuration was-determined to be at a lower-flow rate than what was previously specified in the Technical Specifications. Operation of VA during a FHA ' event will reduce resultant doses since-a significant fraction of the released radiciodines will be adsorbed on the charcoal filter.

4-q

based on the approval of as-built VA-66 operation through NRC review, Therefore, determined that this change does not involve a significant hazards OPPD has consideration as defined in 10 CFR 50.92.

The proposed change will not result in a condition which significantly a',ters the impact of the station on the environment.

Thus, the proposed change meets the eligibility criteria for categorical exclusion set forth in 10 FR 51.22f.c)(d.) and pursuant to 10 CFR 9

51.22(b) no environmental assessment need be prepare 5

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