ML20079L127
| ML20079L127 | |
| Person / Time | |
|---|---|
| Site: | 05000000, Grand Gulf |
| Issue date: | 01/11/1983 |
| From: | Harold Denton Office of Nuclear Reactor Regulation |
| To: | Michelson C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| Shared Package | |
| ML082380477 | List: |
| References | |
| FOIA-83-408 NUDOCS 8302070298 | |
| Download: ML20079L127 (3) | |
Text
-
=
l
.I t s n!
- t tiv cot,".'!sslON e c. e v, g
q t'111?Sb
~':7Af,DU'1 FOR:
Carlyle Michelson, Director Office for Analysis and Evaluation of Operational Data i
F, v.'< -
Aro'.d E. Dwton, Dir ector Of fice of l,. clear Reactor Regulation
SUBJECT:
ABON DIOX1DE SYSTEMS USED FOR FIRE ROTECT10ti
- 17. OR ADJACEt;T TO CRIT 1 CAL AREAS - M: 1RA!;DUM D;TED JULY 28, 1982 The items identified in the subject memorandum and those in the attached me.morandum to R. Vnllmer and E. Jordan, dated January 2E, '982, were discussed during an A. gust 24, 1982 meeting attended by M 5eyfrit and F. Ashe of your c f fice and the following from tiRR:
V. Johnston, V. Benaroya, R. Ferg 3on, J. Stang and F. Nolan.
As a result of our review and this meeting, we have the following comments relative to the issues you have raised.
First, with respect to the four items identified in your July 28, 1982 memorandum:
1.
Recognizing the force developed in the Grand Gulf cvent, was missile generation considered during the reviews of CO, use in areas con-taining equipment required to prevent or mitighte reactor accidents or in areas adjacent to such locations?
tlRR Branch Technical Position (BTP) CMEB 9.5.1, Item C.5.3 states that consideration shoyld be given to the " conflicting requirements for venting during C0 injecting to prevent overpressurizaticn versus sealing to prevent loss o a pnt."
Applicants and licensees are aware of BTP CMES 9.5.I and shoul-therefore consider this potential problem during the design of such s :.tems.
However, we do not requirc or receive the level of detail
. the design information submitted 'f the applicant to allow a meaningfu review of the potential of missilt generation during CO injection.
2 The Grand Gulf event s the first. incident of this type trat we became aware of.
As part of our review of Grand Gulf, we did nct audit whether the applicant had considered overpressurization in the areas where CO was used as a fire suppressant.
2
',. W ~
X4 p8302070>$p XA Copy Has Been:Sent to.fDR 2
l g
/
L l
4 E
'k Carlyle */..d virm. ;
2.
Has the degradation in the per'or.manct cf solid state desices result inc f rom exposure to tne coolino ef f ect of C0} been reviewed?
(ibnj solid state devices are rated fb scrvice onl to O C.
The 0
melting point of CO is -56.6 C.)
2 Itcm C.5.e of BTP CMEB 9.5.1 aise states that consideration should be given to the " possibility of se dary therrml shock (cooling) damage" in conjuncticn. tith the planned se of C0 s ppression systems.
The 7
irnpingement of cold CO n s lid state devices and other instrumentation 2
in some tests has gcr.ci ated spurious signals but we are not aware of any conponent failures. This potential probicm 1,3s been brought to applicants' attention verbally on several occasions, he...er, it has not been part of our official audit review.
3.
Has the effect of rapid abandonment of the control room in the event of CO, actuation been rcviewed? Can accidents resulting from the need for C0 operation (or perhaps caused by it) bc adcquately 7
cor trolled in such cases?
NRR has not, as yet, approved C0 fire suppression systems for use in the general control room area, burcurrentguidelinesprohibitsuchuse in the future.
However, the use of a C0 fire suppression system is 7
under ccosideration at the Perry facility fer application in enclosed instrument cabinets, panels and cable chases located in the control room floor and walls (PGCC system).
In these applications, some limited leakage of C0 into the control room is expected to occur. For us to p
approve this system, the applicant has to demonstrate that the concentra-tion of C0 will meet the guideline of Regulatory Guide 1.78, " Assumptions 2
for Evaluacing the Habitability of Nuclear Power Plant Control Room During Postulated Hazardous Chemical Release," and our guidelines delineated in BTP CMEB 9.5.1, paragraph C.S.3.
4.
Has the possib'ility of C0, entry into the ventilation system and its effect on personnel in other plant areas been considered?
C0 sup;ression systems may be approved for application in many areas, 7
suth as. diesel generator rooms, MG room, tm tery rooms or ccmputer room.
in thest applications, the licensee needs t-demonstrate that leakage r
from sut rooms will not affect the habitabi'ity of those adjacent areas of the f.:ility.
With regard to personnel e-try into confined rooms that employ at :omatic C0 suppression systems, BiF 9.5.1, Item C.5.e, recommends p
I a prediscuarge alarm system and a C0 discharge delay to permit persannel t
7 egress.
These features are a part or our rev u e process for approval of C0 5751" 5*
2 In summary, items 1 and 2 have not been a part cf our review of fire protection features.
In the future, however, n2 will determine if these potential hazards have been considered in the fire protection design process.
Items 3 and 4 are part of our review where CO systems are used.
2 r%
~'
C
.n1,le Michelson.
Tinally, in your January EE,
.a.arandum you identif ied cc:.cern m.cr the potential iriadverten'. act at ion of liquid fire sup; ression tystems and subsequent loss cf a damace to safety related equipment.
Le have reviewed licensee cvent re; orts relating to systc interaction accurrences that v.ere es perict:ccd cver the past several years.
Based on this review, i t appears that scce lic(nsees have not irplcmented our guidelines properly, and tlu.s ha$e designs that have the potential for such interactions.
L'c arc d.: cl: ping a document appr.,priate for use as an IE bulletin r,r circula h;ch will discuss the:e events and recc mend steps to prevent fature such occurrences.
Th:- effort is i
e).pected to be completed i n the t.c ar f ut ure.
L'e will sc d you a copy at that time.
/
l p '?~e-Harold R. Denton, Director Office of fluclear Reactor Regulation
Enclosure:
Memo to R. Vol'r er end E. Jordan Dated Jan. 26, 1952 gea 4
e A