ML20009H264

Application for Amend of License DPR-30 Revising App A,Tech Specs to Implement 10CFR50.59 Reload Licensing W/Barrier Fuel & Odyn Analyses

ML20009H264
Person / Time
Site:	Dresden, Quad Cities
Issue date:	07/27/1981
From:	Swartz E COMMONWEALTH EDISON CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
Shared Package
ML17194A064	List: ML17194A063 ML17194A065 ML20009H264 ML20009H267
References
NUDOCS 8108070120
Download: ML20009H264 (6)

Text

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'. D Commonwealth Edison O ) Oru First National Pina. Chicrgo. _ Illinois O - Address Reply to: Post Office Box 767

. Chicago,1;linois 60690 a m July 27, 1981 g E}s Mr. Harold R. Denton, Director g3 N0'f L'8 F s

1. AUG 0 71983 , o Office of Nuclear Reactor Regulation $

U.S. Nuclear Regulatory Commission u,,,%tg mmy,D 'h Washington, DC 20555 c' , p

Subject:

Quad Cities Station Unit 2 73i .)bb Proposed Amendment to Appendix A Techn'. cal Specifications to Facility Operating License DPR-30 to Implement 10 CFR 50.59 Reload Licensing with Barrier Fuel and ODYN Analyses NRC Dockel Mo. 50-265 References (a): Letter, T. A. Ippolito to D. L. Peoples dated March 20, 1980 (QC-2 Am. 51)

(b): NED0-24259-A, " Generic Information for Barrier Fuel Demonstration Bundle Licensing", February, 1981. Reviewed in R. L. Tedesco letter to R.

E. Engle (GE) dated November 12, 1980 (c): NED0-24146A " Loss-of-Coolant Accident Analysis Report for Dresden Units 2, 3 and Quad Citiet 1, 2 Nuclear Power Stations" Revision 1, April, 1979 as subsequently modified by Erratta and Addenda Nos.1, 2, 3, 4, 5, and 6 (Attached).

(d): NE00-24154 and NEDE-24154-P, Volumes I, II, and

III, " Qualification of the One-Dimensional Core Transient Model for Boiling Water Reactors,"

October, 1978.

l l (e): Letter, R. H. Buchholz (GE) to P. S. Check, l " Response to NRC Request for Information on

ODYN Computer Model," September 5, 1980.

(f): Letter, R. H. Buchholz (GE) to P.S. Check, "0DYN Adjustment Methods for Determination of Operating Limits," January 19, 1981.

' (g): Letter, R. F. Janecek to H. R. Denton dated May 12, 1981.

I g tsd i 8108070120 810727 pl p 8 E I

PDR ADOCK 05000265 W [/

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Dear Mr. Denton:

Pursuant to 10 CFR 50.59, Commonwealth Edison proposes to amend Appendix A, Technical Specifications, to Facility Operating License DPR-30 to support the review of future reloads for Quad Cities Unit 2 by Commonwealth Edison in accordance with the provisions of 10 CFR 50.59. The preparatory changes approved previously in Reference (a) do not sufficiently bound the impending Quad Cities Unit 2 Reload 5 Cycle 6 reload primarily because the barrier fuel demonstration core design includes new bundle designs not addressed previously and because this will be the first time the unit is analyzed with the ODYN transient code.

-The proposed changes in Attachment I have received On-Site and Off-Site review and approval. The significant changes are discussed below.

Barrier Fuel The only preparatory changes proposed are:

a. the use of alternate wording in the Safety Limit Bases discussion of the cladding's role as one of the physical " barriers" for release to the environs, (pg.

l.1/2.1-4) and

b. incorporation of the generic barrier fuel topical report (Reference (b)) as a reference in the discussion of the MCPR safety limit (pgs. 1.1/2.1-4 and 5), and

c. including barrier fuel MAPLHGR curves (discussed in the next section).

The first item is intended to avoid multiple uses of the term i " barrier" with respect to the clad and the second is recommended for i completeness.and to establish the barrier topical as the base i

licensing document.

. MAPLHGR Limits

< NE00 24146 (Reference (c)) contains the previously approved ECCS analysis for Dresden Units 2 and 3 and Quad Cities Units 1 and 2 and continues to serve as the basis for the generation of MAPLHGR  ;

limits for new fuel types.

~

New MAPLHGR limits for barrier fuel types P80GB298, P80GB263L, P8DGB284 and P8DGB265L are included in the proposed changes to Figure 3.5-1. The limits are based on Errata and Addende Nos. 5 and 6'to Reference (c), which are provided for your use in Attachment 2 to this letter. A non-barrier fuel type which is otherwise identical to the P80GB265L design is also utilized in the Quad Cities 2 Cycle 6 reload core. General Electric has stated

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I that the barrier fuel type MAPLHGKs apply directly to the

corresponding non-barrier fuel types for otherwise identical designs. The lower figure of Sheet 2 of the proposed Fig. 3.5-1 reflects this.

In previous MAPLHGR revisions, calculated limits for non-prepressurized fuel have been conservatively applied to otherwise identical prepressurized fuel due to the unavailability of the slightly relaxed prepressurized MAPLHGRs. As indicated in the lower figure of Sheet 2, this distinction is now possible for the 2.65 standard P8x8R design and both curves are therefore included.

It should be noted that the current Sheet l'for 7x7 fuel is replaced by the 2.97 barrier P8x8R curve and that the 2.65 standard 8x8R and 2.82 standard P8x8R curves are unchanged but merely replotted on the revised Sheets 2 and 4, respectively. Also note that although the 2.82 standard P8x8R curve only extends to 30,000 MWD /T, it is not yet being used in Quad Cities Unit 2. All fuel

types to be used in Cycle 6 have MAPLHGR limits which extend to j 40,000 MWD /T planar exposure. This easily exceeds the maximum

conceivable nodal exposures for the scheduled cycle length.

DELETION OF 7x7 FUEL LIMITS MC9R, MAPLHGR, and LHGR operating limits for 7x7 fuel have all been removed as there will be no 7x7 fuel in the Quad Cities 2 Cycle 6 core.

PRESSURE SAFETY LIMIT CHANGES DUE TO ATWS RPT

The NRC required installation and implementation of

Recirculation Pump Trip (RPT) for ATWS mitigation as of January 1, i 1981. Although it reduces peak pressures for transients without scram, it carries a side effect of increasing the peak pressures for severe pressurization events with scram (such as LR w/o BP or MSIV closure w/o valve position trip). On the positive side, piessurization events which exceed the RPT set point (1250 psig) can l reach high steam dome pressures without exceeding the peak vessel or

! coolant system pressure criteria as a result of the lower reactor pressure drop which occurs without forced recirculation flow.

< Without RPT maximum pressure differences from the steam dome to the

{ bottom of the vessel were less than 30 psi. With RPT the total reactor a P is reduced to less than 20 psi.

The assumption in the current bases for the pressure safety limit is a 50 psi a P (i.e. 1375 psi -- 1325 psi) which is

conservative in either case. The proposed change retains adequate conservatism by resetting the safety limit at only 1345 psig as measured in the steam dome. The assumed pressure difference is still 30 psig to the bottom of the vessel which will assure compliance with the ASME code criteria of 110% of vessel design i

- _ . . - - ~ _ . _. _ . . . -. _ _ - _ - _ - _ . ._ -. -

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pressure (i.e. 110% x 1250=1375 psig). Since the vessel peak pressure (bottom) is specifically calculated for each reload for the postulated multiple failure MSIV closure event (no valve position

trip scram and no Electromatic Relief Valve Flow), the proposed f

change does not affect our ability to identify potential problems 4 with ASME compliance.

i Wording changes in the bases have also been incorporated

! which clarify that compliance of-the peak vessel pressure with the

ASME criteria also assures compliance of the primary system piping pressures with the USASI criteria for the limiting point -(i.e. less than 1410 psig at the lowest point in the recirc. suction line).

4 These changes were recommended by GE due to the false. implication in the current bases that all points in the primary system must remain less than the ASME criteria for the vessel (1375 psig).

ODYN TRANSIENT CODE IMPLEMENTATION

The ODYN transient analysis computer code is used for analyzing rapid pressurization events in a more sophisticated manner ,

3 than its predecessor, the REDY code. Reference (d) is the three

volume generic topical report which describes the model and its qualification. Reference (e) contains responses to NRC questions but also forms the primary reference for the implement 6 tion procedure, i.e. adjustment of ODYN MCPR results to account for statistical treatment of four parameters

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a. initial core thermal power

b. CRD scram times

c. model uncertainty L d. regressional fitting uncertainty l This statistical approach ("0ption B") was negotiated with the staff during the first 9 months of 1980 and is intended to establish a "95/95" basis for licensing ODYN. That is, the MCPR ooerating limit should provide a 95% probability with 95% confidence that the limiting pressurization event will not cause MCPR to fall below the i fuel cladding integrity safety limit. In order to accomplish this,

a statistically based scram time distribution which is faster tnan those in the current Technical Specifications was applied for each of several plant groupings of similar design in order to define generic Statistical Adjustment Factors (SAFs) which can be applied to pidnt specific results. The SAFs~also incorporate the statistical treatm nt of power level, model, and fitting uncertainties. The net result for BWR2 and 3's is a SAF of +0.006-

S-which is added to the ODYN calculated aCPR/ICPR.

3 then calculated using the Reference (f) equation of:The new ICPR is SL 1 -paCPRe 4 ICPRnew= + .006' L ICPRc -

where SL=MCPR Safety Limit (1.07)

A CPRc= ODYN calculated transient- A CPR (unadjusted)

ICPRc= ACPRc + SL 2

3 the assumed scram time distributionTo assure and demonstrate consistency

a " scram time conformance procedure" in the calculation of the SAFs, makes the MCPR operating limit is now required which basically during the normal surveillance. a function of scram times as measured Specifically, the overall average

- of all(T' cycle 20% ave)insertion scram time must be evaluated data measured with respect to the 5%

to date in the curren significance level criteria generic SAF. for the distribution If the running average (7'g) assumed in deriving the required. exceeds]"g a MCPR penalty is The MCPR penalty is applied increasing limit between the Option B value at 3'g to- a morein the form of a li which is the CR0 surveillance limitconservative NRC-determined value (" Op specification 3.3C.2. for 20% insertion from-The Option A limit (f) and is simply equal to ICPRis also defined in References (e) and penalty on the unadjusted ODYNcresults). multiplis_ by 1.044 (i.e. a 4.4%

The scram time dependence of the MCPR t

3.3.c/4.3.c and 3.5.k.the proposed changes to limit isSpecifications Technical reflected in and bases The MCPR

' reloads with a limiting f uel ty3e ACPR of up to .29. limits were chosen to bound fu noted that bases page 3.3/4.3-10, It should be includes changes previously proposedconcerning scram in Reference (g) associatedinsertion times, with RPS delay and response times.

4 is an attempt The proposed form of the scram time dependent MCPR limits

' -implementation of the ;onformance procedure.to simplify the actual Technical originaliy suggested either an explicit versionGeneral Electric definitions in the LCO text) or a graphical version.(full equations and challenges in plantare extremely complex and would have presented significant'Both m fproposed implementation and operator training. The specifications, offers significantapproach, while still advantages complicated over other relative to previous alternatives while incorporating small conservatisms which should l

i not impact p* ant operation.

The conservatisms include:

a. the assumption of maximum scram timing frequency allowed by Specification 4.3.C.2 (that is, a full core data set at B0C and half core data sets every 16 weeks thereafter),

b. The assumption of an operating cycle length of.24 months (excluding refueling) which is longer than what is currently considered technically feasible without excessive coastdown and associated economic corstraints,

c. a conservative choice of the nearest RPIS switch (dropout of pos. 39) in the selection of the mean (#)

and standard deviation (c') associated with calculat ing j tha 5% significance level criteria ( 7'B),

d. conservative rounding of both 9 8 and 3 A values, and

e. use of the rounded down5I B and 3A values in calculation of the slope an Linterc_ept values for the linear MCPR penalty between > B and TA.

Pursuant to 10 CFR 120, Commonwealth Edison'has determined that the proposed amendment is Class III. As such, a fee remittance in the amount of $4,000 has been enclosed.

Please address any questiont you may have concerning this matter to this office.

Three (3) signed originals and thirty-seven (37) copies of this transmittal are pro',-ided f or your use.

Very truly yours,

f. h y--

A -

E. Douglas Swartz Nuclear Licensing Administrator attachments cc: RIII Inspector - Quad Cities SUBSCRIBED and SWORN to before me this 3/ M day of h /ta. , 1981 Ate 4/

Notary Public 2326N

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