AECM-86-0052, Application for Amend to License NPF-29,changing Tech Specs to Lower Requirement for Standby Gas Treatment Sys Heaters in Surveillance 4.6.6.3.d.5 to 50 Plus/Minus 5 Kw
| ML20141G127 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 02/17/1986 |
| From: | Kingsley O MISSISSIPPI POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML20141G088 | List:
|
| References | |
| AECM-86-0052, AECM-86-52, TAC-60700, NUDOCS 8602260167 | |
| Download: ML20141G127 (4) | |
Text
,.-
BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION LICENSE NO. NPF-29 DOCKET No. 50-416 IN THE MATTER OF MISSISSIPPI POWER & LIGHT COMPANY and MIDDLE SOUTH ENERGY, INC.
and SOUTH MISSISSIPPI ELECTRIC POWER ASSOCIATION AFFIRMATION I, O. D. Kingsley, Jr., being duly sworn, stated that I am Vice President, Nuclear Operations of Mississippi Power & Light Company; that on behalf of Mississippi Power & Light Company, Middle South Energy, Inc., and South Mississippi Electric Power Association I am authorized by Mississippi Power & Light Company to sign and file with.the Nuclear Regulatory Commission, this application for' amendment of the Operating License of the Grand Gulf Nuclear Station; that I signed this application as Vice President, Nuclear Operations of Mississippi Power & Light Company; and that'the statements made and the matters set forth therein are true and correct to the t of my knowledge, information and belief.
A.
~d
/
O. W./ king e-STATE OF MISSISSIPPI COUNTY OF HINDS SUBSCRIBED AND SWORN TO before me, a Notary Public, in and for the County and State above named, this /7//, day of Fe' 6 r y. u
, 1986.
J (SEAL)
No g Public My commission expires:
ad,4s.27./ spy pa22gg g6,oaopje P
J14SF85042401 - 4
.w y'
- y q1
,L
-x-
'S
{'
z.
d-
- C 4
Att chment I to' 4
i
~ '
SUBJECT:
NPE-86/003-
- Technical Specification' Surveillance Requirement 4.6.6.3.d.5; K
.page 3/4-6-56" DISCUSSION:
Surveillance Requirement'4.6.6.3.d.5 requires that at least V'
once per 18 months the standby gas treatment: system heaters are
= verified to. dissipate 50 1-5.0 KW when tested in'accordance Mth ANSI N510-1975 :(except for"the phase balance criteria; stated'in'Section 14.2.3)..These1 heaters were tested in March 1985fand were found to dissipate greater than 45 KW.
Sa veillance Requirement 4.6'.6.3.d.5 was again performed,on
~
February 15,.1986 for B Train. -The test results showed~a heat.
dissipatio'n of;1ess than145-KW, which-does'not meet the surveillance requirement.. As a result,.the,B Train;of the-standby'~ gas treatment' system was declared inoperable and entry into' Operational ~ Conditions'1,.2,t 3 and
- was prohibited..
MP&L is requesting by this proposed change that Surveillance.
Requirement 4.6.6.3.d.5.be revised to reflect a' heat-dissipation requirement of 48 SKW.-
JUSTIFICATION: The operability of the standby gas treatment systems within secondary' containment.' ensures that' sufficient iodine removal;
't carability will be available in-th'e eventL-of a LOCA.' 'The f[, l ireduction in containment iodineT nventory reduces.the.resulting i
J site boundary radiation doses associated with containment leakage. The operation of this: system and resultant iodine removal capacity are consistent with the assumptions used in i
the LOCA analyses. Continuous' operation of-the system with thei heaten/ operable for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> over a 31-day 1 period is' sufficient to rede'ce the buildup of moisture on-the-adsorbers and'HEPA-filters.
..The heaters originally ins *o 1.ad'in the standbyLgas treatment h
system were 50KW nominal W +.pplied by vendor CVI.- These-y heaters were not qua*1 % r the' requirements:of NUREG 0588 and s
were subsequently red.:.at'
,- March 1985 with 48 KW nominal'
){
. heaters-supplied by. vendor Ellis and Watts that'were qualified..
The size;(50 KW nominal)'of the originally.' installed: heaters I
should not be-used as the basis for_the' heat dissipation requirement presently in Surveillance Requirement 4.6.6.3.d.5..
~
The s' ire ~(48KW nominalc) of. the presently l installed heaters /
should be'used.to form the' basis forJthe value used;in;this o?
surveillance. For the SBCT system the'new. heaters'have'been-marginal when:trying to' comply with: Surveillance Req'uirement-4.6.6.3.d.5 to meet:50.i'.5 KW heat. dissipation.$ Alsmall' drop;in:
4
' incoming line voltage can mean'theJdifference'in p'assingcor failing the; surveillance.
In' order to' solve this problem, MP&L 3
e i
t I
1,f r
-3')
L J1thITC86021401 # 1 -
+
y a
=:
y x1,
- m..,
m
?".
1 Attacha ntil to-
5 n
has; performed a calculation-to' determine ~the minimum heat' dissipation.requiredffor'the SBGT system'in order'to meet ~ design; requirements. JAs explained;below, the: calculation demonstrates; that a minimumLof approximately 21.5 KW heat dissipation inteach
- SBGT train will reduce the relative; humidity of the air leaving l
~
the heaters to 70%..The proposed, change:to'48 i 5KW will ensure that design ~ conditions are met.;
The calculation to datermine needed heater' size for SBGT assumes;
~
an incoming air temperature of.150'F with 100% relative humidity.
~
and a SBGT system flowrate of 4500 CFM (4000 CFM required).>-The;
~
heaterisize required to reduce.the relative-humidity offthe'
~
air, leaving the-heaters;to 70% is approximately.21.5 KW.; The requirement to reduce-the' relative humidity from 100%.to'70%f under worstJease DBA conditions is.specified~in Regulatory. Guide'
~
2 1.52 Revision 1.:
v.
SIGNIFICANT HAZARDS CONSIDERATION:
The proposed change,to'the technical specifications reduces the-heat dissipation requirement of'the heaters in theLSBGT system from 50
~5 KW to 48 5 KW.
The 50 2 5 KW is based on.the heaters originally installed and.not on the heaters presently:
installed. Regulatory Guide-1.52~ Revision 1. requires"a heater sized to reduce the relative humidity of the incoming air from 100% to 70%.dur'ing postulated DBA conditions.'.The proposedy48-1.
~
i
. 5~KU heat dissipation exceeds these design requirements since a-minimum of approximately 21.5 KW is all that is required'to':
ensure 70% relative humidityfair leaving the heaters.-
The proposed change does-not involve a significant increase in the probability or consequences of anJaccident.previously evaluated because the propos~ed change to a 48'i 5 KW
~
meets the' design requirement to lower the~ relative humidity of-the incoming air from 100% to 70% under worst possible DBA.
conditions. This-change reflects'present.as-built system designiwhile still ensuring:that worst case DBA specification
~
requirements are met' ~Since thisichange'doesLnot ' adversely-
- affect. previous accident analyses requirements, there is no increase-in the probability or consequences;of an accident:
previously evaluated.'
The proposed change,does not c,reate.the possibility,of a new or different. kind of accident 4from any accident previously,.
-evaluated because: calculations indicate that a minimium of.
approximately'21.5 KW is' adequate to ensure 70%. relative
~ humidity air leaving-the heaters. This change' doe's not affect-1 the performance or design intent of'the'SBGT system. heaters.
i Therefore, this change does notiadversely affect the accident analysis and does~not create the' possibility of-a new or different kindiof accidentefrom~any accident.previously evaluated.
"J16ATTC86021401 - 2 o_
I
'i
+
~Attschm:nt l'to AECM-86/0052' h:,
The proposed change does not involve.a significant reduction in the. margin of safety because calculations demonstrate that a.
minimum of.approximately 21.5 KW heat dississipation.ic all that is required to ensure-70% relative humidity air = leaving the heaters. The calculation conservatively assumes a SBGT flowrate of 4500 cm when only 4000 CFM is required 'by FSAR.
analysis'_ assumptions. Therefore,.the proposed minimum of 48 1.5 KW is a conservative number with respect.to requirements'and the margin'of safety is not reduced.
Therefore, the proposed change involves no significant hazards considerations.
i f'
J16ATTC86021401 - 3 e
., _