ML18010A684
| ML18010A684 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 07/10/1992 |
| From: | Starkey R CAROLINA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NLS-92-182, NUDOCS 9207150316 | |
| Download: ML18010A684 (7) | |
Text
ACCELERATED DISTI?JBUTIOQ DEMONST$M.TION SYSTEM i/~
REGULA I INFORMATION DISTRIBUTZOOYSTEM (RIDE)
ACCESSION NBR:9207150316 DOC.DATE: 92/07/10 NOTARIZED: NO FACI'Ii:50-400 Shearon Harris Nuclear Power Plant, Unit 1, Carolina
- AUTH.NAME AUTHOR AFFILIATION STARKEY,R.B.
Carolina Power
& Light Co.
RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
DOCKET 05000400 R
D S
05000400 NOTES:Application for permit renewal filed.
SUBJECT:
Submits supplemental info to 920310 application for amend to License NPF-63,revising TS re RWST 6 safety injection accumulator boron concentrations s spray additive tank a
boric acid tank levels,per NRC request.
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TITLE: OR Submittal:
General Distribution RECIPIENT ID CODE/NAME PD2-1 LA LE,N INTERNAL: ACRS NRR/DOEA/OTSB11 NRR/DST/SELB 7E NRR/DST/SRXB 8E OC LFMB REG FILE 01 EXTERNAL: NRC PDR COPIES LTTR ENCL 1
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1 RECIPIENT ID CODE/NAME PD2-1 PD NRR/DET/ESGB NRR/DST 8E2 NRR/DST/SICB8H7 NUDOCS-ABSTRACT OGC/HDS1 RES/DSIR/EIB NSIC COPIES LTTR ENCL 1
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NOTE TO ALL"RIDS" RECIPIENTS:
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CNILL Carolina Power & Light Company P.O. Box 1551 ~ Raleigh, N.C. 27602 R. B. STARKEY,JR.
Vice President Nuclear SeNices Department QUL 10 >992 SERIAL:
NLS-92-182 10CFR50.90 United States Nuclear Regulatory Commission ATTENTION:
Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT DOCKET NO. 50-400/LICENSE NO. NPF-63 SUPPLEMENTAL INFORMATION TO REQUEST FOR LICENSE AMENDMENT RWST AND SAFETY INJECTION ACCUMULATOR BORON CONCENTRATIONS; SPRAY ADDITIVE TANK AND BORIC ACID TANK LEVELS Gentlemen:
On March 10, 1992, Carolina Power
& Light Company (CP&L) submitted a Request for License Amendment for the Shearon Harris Nuclear Power Plant (SHNPP) pertaining to the Refueling Water Storage Tank (RWST) and Safety Injection Accumulator boron concentrations, and the Boric Acid Tank (BAT) and Spray Additive Tank (SAT) levels.
By letter dated May ll, 1992, CP&L revised the values submitted for the Boric Acid Tank.
Subsequent to these submittals, the NRC Staff reviewer has requested clarification relative to the impact of this Request for License Amendment on the SHNPP Loss of Coolant Accident (LOCA) analyses.
The purpose of this letter is to provide supplemental information concerning LOCA considerations to facilitate the NRC's review.
A summary of those considerations is provided in Enclosure 1.
Additionally, CP&L has identified the need for clarification concerning pH levels for the Containment Spray System (CSS).
Enclosure 2 outlines the basis for CSS pH and the impact of the proposed Technical Specification change on pH ranges.
Both of the above issues have been discussed with the NRC Staff reviewer.
CP&L has reviewed the 10CFR50.92 Evaluation previously submitted on May 11, 1992 and determined that the conclusions of the significant hazards evaluation (probability or consequences of an accident, possibility of a new or different kind of accident, and margin of safety) remain valid.
Please refer any questions regarding this submittal to Mr. Lewis S. Rowell at (919) 546-2770.
Yours very truly, R.
B. Starkey, Jr.
92071503i6 920710 PDR ADOCK'5000400 P,,
Document Control Des NLS-92-182 / Page 2
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Enclosures:
1.
LOCA Considerations 2.
Clarifications on pH R.
B. Starkey, Jr., having been first duly sworn, did depose and say that the information contained herein is true and correct to the best of hi's information, knowledge and belief; and the sources of his information are
- officers, employees, contractors, and agents of Carolina Power
& Light Company.
My commission expires: 2(Is/gQ cc:
Mr. S.
D. Ebneter Mr. N. B. Le Mr. J.
E. Tedrow (gARV g
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ENCLOSURE 1 TO SERIAL:
NLS-92-182 Page 1 of 1 SHEARON HARRIS NUCLEAR POWER PLANT DOCKET NO. 50-400/LICENSE NO. NPF-63 SUPPLEMENTAL INFORMATION TO REQUEST FOR LICENSE AMENDMENT RWST AND SAFETY INJECTION ACCUMULATOR BORON CONCENTRATION SPRAY ADDITIVE TANK AND BORIC ACID TANK LEVELS LOCA CONSIDERATIONS A function of the Refueling Water Storage Tank (RWST) is to provide the principal volume of emergency coolant delivered by the Safety Injection System (SIS).
Since mitigation of the consequences of a LOCA defines the performance requirements of the SIS, the proposed Request for License Amendment has been carefully evaluated with respect to the SHNPP FSAR Chapter 15 LOCA analyses.
While LOCA considerations were mentioned throughout CP&L's original submittal, the following summarizes those considerations:
)
Changing the RWST boron concentration does not affect the calculation of Peak Cladding Temperature or the percentage of zirconium-water reaction analyzed in FSAR Section 15.6.5.
In the relatively short period covered by this calculation, the negative reactivity needed to shutdown power production in the core is provided by other means:
void formation for Large Break and control rod insertion for Small Break.
I Since control rod insertion cannot be absolutely assured after a Large Break, calculations show that the Reactor Containment Building sump concentration (combining the
alone, is sufficient to keep the core subcritical at the cold conditions that would be applicable in evaluating long-term consequences.
This is a standard part of the safety evaluation of reload core designs.
pH considerations are described in Enclosure 2.
Avoiding excessive boron precipitation in the core following a LOCA is necessary for maintaining a core geometry that is amenable to long term cooling.
This is the purpose for switching from RCS cold leg injection to RCS hot leg injection during the long term cooling phase.
T¹ primary objective is to backflush the core.
With the increase in RWST boron concentration, operators are directed to perform this switchover earlier.
This change in switchover time is described in CP&L's March 10, 1992 submittal.
Since there will be increased core decay heat at this earlier time of switchover to hot leg injection, hot leg delivery flowrates have been evaluated with respect to cooling requirements and found acceptable.
ENCLOSURE 2 TO SERIAL:
NLS-92-182 Page 1 of 2 SHEARON HARRIS NUCLEAR POWER PLANT DOCKET NO. 50-400/LICENSE NO. NPF-63 SUPPLEMENTAL INFORMATION TO REQUEST FOR LICENSE AMENDMENT TION RWST AND SAFETY INJECTION ACCUMULATOR BORON CONCENTRA SPRAY ADDlTIVE TANK AND BORIC ACID TANK LEVELS CLARIFICATIONS ON H
was ori inall designed to maintain a The SHNPP Containment Spray System (CSS) was orig y
H in the ran e of 8.5 to 11.0 and its effectiveness in removing bed in SHNPP FSAR Section 6.5.2.3.2.
The method of elemental iodine is descri i
a removal time constant described n t e g
require the use of a time dependent spray p
t e SHNPP CSS design is documented in NUREG-a e y acceptance of the S
of Shearon Harris Nuclear Power Evaluation Report Related to the Operation o
earon a
j Plant," November 1983.
-site calculations for a LOCA event are described in FSAR 0 A Re ardless of the calculated value 15.6.5 and FSAR App~~di~ 15.0.A.
Reg p
dose calculations is conservatively limited.
T e s a s
e of the SHNPP off-site calculation results, including t e the s ra removal coefficient are conservative assumptions regarding t e spray m
documented in NUREG-1038.
er 1988 Revision 2 of Standard Review Plan
( SRP) 6.5.2 (NUREG-0800) evision d i 1 dependence on the pH value for olved iodine and deleted the requirement evision reco nize m noma ep fresh spray solution having o
sso io i i
related to spray additive and t
S ra S stem Design Criteria," as t re a e
o o
s s
e h d f 1 ulating the spray removal ol s stems.
- Further, the met o
or ca c The revised method is now independent of the spray i
- t r
d i
ue and is the same method as that used and descri e
n pH value and s
e a
6.5 2.II(1).
was also revised to Section 6.5.2.3.2.
Revision 2 of SRP
.g dine retention only be made when the require that p
an assum tion of long-term zo ne et of the s ray recirculation mode is equilibrium sump solution pH at the onset o t e sp above 7.
t e SHNPP Technical Specifications increases the volume As described in SHNPP Technical dium h droxide used as a spray additive.
As descri e
in ses 3 4.5.4 and 3/4,6.2.2, the objective is to maintain the
"~
ent sum solution pH within the range 8.
to o
contaxnmen sump of iodine and the effects o
c or e an f hl id and caustic stress corrosion.
evolution o
o
.2-2 and 6.5.2-3, the sump solution has a low pH As shown xn FSAR Figures 6.5.2-2 and value initia y,
u 11 b t it rapidly increases as sodium hydroxi e n
e p
y owever since the
- eductor, and spray flowrates remain unchanged sodium hydroxide concentration, al s ra H will decrease from 8.6 to approximate y
ue o
the initial spray p
wi n.
Durin long-term recirculation, the i
rease in RWST boron concentration.
ur ng ong-ncrease 8.5 to 11.0.
spray p wi H ll increase to within the range of
ENCLOSURE 2 To SERIAL NLS 92 182 page 2 of 2 11 d t'H will have no affect on the calculated spray removal coefficient since the pH value was not specifically required xn t e me o
described in t e u
he SHNPP FSAR.
- Further, since SRP 6.5.2, Re~ision 2 has adopted e im act on a similar approac
, i is co h
t is concluded that there will be no adverse impac on the calculated spray coe z.cz.en or e
ff t r the radiological dose calculations which d ne is assured se a more conservative
~alue.
Long-term retention of iodine is assure because the sump solution will reach a pH o at east a
e use a more cons spray recirculation mode an wx, rapi d
d ll r pidly increase to a value of approximately d
8.5 at the comp etymon o
e so 1
f th dium hydroxide addition.
This is the require minimum value state in t e ases d
th B ses of the SHNPP Technical Specifications previously re erence e
ma f
d.
Th ximum spray and sump solution pH value wall no be revised and does not exceed 11.0 as is currently required.
ll be no adverse impact on material conditions (corrosion) or equipmpnt qualification because, while the minimum pH value wwill decrease 8.6 to 8.2 it will still be above the neutral pH of 7.0 which is considered to-be a minimum value necessary to prevent stress corrosion cracking as recommen e
n ded in SRP 6.1.1, Revision 2,Section III.B (a).
Since aximum H value is not changed, the calculated hydrogen production rate f
luminum corrosion will not change esther.
e y
og p
The h dro en roduced from rom a umi sion due to the increased acidic affect of changing the RUST and SIS zinc corrosz.on ue to a maximum of 2600 accumulator.boron concentration from a maximum 2200 ppmB o a ppmB is discussed in CP&L's March 10, 1992 and May ll, 1992 submittals.
Based on the'bove, a slight reduction in the minimum spray pH wrll have no im act on the proposed Technical Specification changes, supporting analyses, mpac on or conclusions that CP&L submitted on March 10 1992.