ML20081K321
| ML20081K321 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 06/14/1991 |
| From: | Creel G BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-REGGD-01.097, RTR-REGGD-1.097, TASK-2.E.4.2, TASK-TM TAC-53365, NUDOCS 9106260254 | |
| Download: ML20081K321 (2) | |
Text
3
,. s BALTIMORE GAS AND ELECTRIC CHARLES CENTER
- P.0, BOX 1475
- BALTIMORE, MARYLAND 21203 1475 Gronot C Cntct Viet Pac siotN1 Nucitan Cwt mov
[200aco-44ss June 14,1991 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:
Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant
{
Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 Unit 2 Containment Vent System Operability; Technical Specification 3.6.1.8 (TACS 53365 and 53366)
REFERENCE:
(a)
Letter from hir, G, C, Creel (BG&E) to Document Control Desk (NRC), dated May 31, 1991, Clarification of Containment Vent Status Gentlemen:
Reference (a) reported the status of containment vent paths for Calvert Cliffs Units 1 and 2. This letter updates that status and confirms the telephone notification made to your stan nn J,,e 10, nj9g that we had, on that date, completed installation of a containment high radianon isolation signal on the containmer.t vent line (MOV-6900 & 6901) for Unit 2. With the completion of this work, we have satisfied the Technical Specification requirements for operability of this system. The footnote associated with Technical Specification 3.6.1.8 allows the deletion of the limiting condition of operation and its associated sarveillance requirement. We will provide appropriate substitute Technical Specification pages in a future amendment submittal.
The containment vent valves will now isolate upon receipt of either a safety injection actuation signal (SIAS) or a high radiation isolation signal. The radiation signal during Modes I through 4 receives its input from the containment high range radiation monitor (2-RE-5317). This is a Regulatory Guide 1.97 post accident monitoring channel. For Modes 5 and 6 the signal input is provided by the containment area radiation monitors (1/2-RE-5316). By completion of this modification, we have established a containment vent path for. Unit 2 which is in full compliance with TMI Action Item ILE.4.2. We expect a similar modification to be completed on Unit 1 during its current outage, and we will notify you upon its completion.
,A 9106260254 910614 PDR ADOCK 05000318 P
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Document Control Desk I
' Junc 14,1991 Page 2 Should you have any further questions regarding this matter, we will be pleased to discuss them with you.
Very truly yours, f
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GCC/ PSF / psf / dim cc:
D. A. Brune, Esquire J. E. Silberg, Esquire R. A. Capra, NRC D. G. Mcdonald, Jr., NRC T. T. Martin, NRC L E. Nicholson, NRC R.1. McLean, DNR.
j J. II. Walter, PSC l
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B ALTIMORE -
,7 GAS AND ELECTRIC CHARLES CENTER e P.O. BOX 1475 e BALTIMORE. MARYLAND 21203-1475 Ge_oRoc C. CRECL Vice Pas sictait NWCatan Ca.tnov 1304) aso+4 4$s May 31,1991 U. S. Nuclear Regulatory Commission Washington, DC 20555 -
ATTENTION:
Document Contrel Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50418 Clarification of Containment Vent Status
REFERENCES:
(a)
Letter from Mr. A. E Lundvall (BG&E) to Mr. D. G. Eisenhut, (NRC) dated April 19,1982, Post TMI Requirements -
(b):
letter from Mr. A. E. Lundvall (BG&E) to Mr. D. G. Eisenhut, (NRC) dated August 11,1981, Response to NUREG-0737 (c)
Letter from Mr. D. H. Jaffe (NRC) to Mr. A. E Lundvall (BG&E),
dated February 1,1982, Issuance of Amendment Nos. 65 and 47 Gentlemen:
- While reviewing containment venting practices, we discovered several items which we felt should be -
brought to your attention. We have determined that an inaccurate statement was made in Reference (a). This do;ument was cited by the NRC in its close out of TMI Action Item II.E4.2.
Additionally, we have determined that there is no documentation which describes a safety analysis for the currently used vent path. We have discontinued all activities not complying with the TMI Action Item requirements by ceasing venting through this path. These matters have been discussed with your staff, and this letter is provided to communicate our plans for resolution of these issues.
TMI Action Item II.E.4.2 -
Reference (a) updated our status on several TMI Action Items including II.E4.2. In this letter, we state that our " containment purge and vent valves" shut on a radiation signal. This statement is not accurate. While our ;. ge valves close upon receipt of a high radiation signal and a SIAS, there were no valves ' designated as " containment vent valves." De valves used for containment venting
'(containment sump isolation valves) close upon receipt of a GIAS, but not on a radiation signal.
Previous correspondence (Reference b) had indicated that only the Containment Purge Valves close upon receipt of a high radiation signal. Only Reference (a) was cited by the NRC in closing out this
- action item (Reference c).
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Document Control Desk May 31,1991 Page 2 In 1982, we decided to modify the hydrogen purge line for use as our containment vent path. A containment radiation signal was installed on this line in 1985; however, due to difficuttly with the detector,it never worked properly. He containment radiation signal to the hydrogen purge line was never declared operable as requ red by our Technical Specifications, and it was not implemented as a vent path. Work is underway raow to provide a high radiation signal which will function during power operation. We are currently in compliance with the intent of TMI Action Item because we have discontinued venting. Because a containment vent path is an operational necessity long term, we believe this TMI Action Item should be held as an open item until an acceptable pathway has been established. We expect this to be accomplished in the very near future.
Alternate Vent Path We have also researched the basis for the use of our alternate vent path. This path consists of using the normal containment sump and venting the containment atmosphere to the ECCS pump room This pathway is automatically isolated by redundant containment isolation valves upon receipt of SIAS. The procedure implementing this path has been in use since 1979, when it was approved as an alternate to our 48" purge valves. We can find no written safety analysis which justifies the use of this path.
We have reviewed this path to determine if its use might have put us in an unsafe condition. It is of minimal safety significance for two reasons, First, the radiological consequences have been evaluated for a LOCA while venting through a similar line and have shown that the associated offsite dose would be negligible. Second, although there is no containment radiation signal on the sump isolation valves, we have identified no plausible accident for which the radiation signal will actuate befe.e SIAS. Because of the diversity and redundancy of the SIAS signal, we have concluded that the lack of a high radiation signal on the sump isolation valves is of minimal safety significance.
We discontinued venting through the sump upon discovery that written analyses could not be located. This path does not fully comply with the requirements of the TMI Action Item.
Future Actions Currently, we have no vent path which is in full compliance with the TMI Action Plan requirements.
Our intention to resolve this issue is to install the modifications necessary to make the hydrogen purge line conform to the NRC approved configurat on. The hydrogen purge line requires several i
modifications to make it operable as a containment vent path. The high radiation signal must still be installed on the valves and an orifice plate must be installed to limit the flow through the line while venting. Both of these modifications are proceeding as expeditiously as possible.
If during the current modifications an operational need to vent occurs, we will take action in accordance with the Technical Specifications to shutdown the plant to Mode 5 to accomplish the venting.
Should an unforeseen obstacle prevent prompt installation of the modifications, we will evaluate the options available at that time, including requesting a waiver of the Technical Specification requirements.
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F Document Control Desk
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May 31,1991
' Page 3 An investigation of the circumstances involved in these issues is in progress.
Should you have any questions regarding this matter, we will be pleased to discuss them with you.
Very truly youn, t
I M
for G. C. Creel Vice President - Nuclear Energy GCC/ PSF / psf / dim cc:
D. A. Brune, Esquire J. E. Silberg, Esquire R. A. Capra, NRC D. G. Mcdonald. Jr., NRC T. T. Martin, NRC L E. Nicholson, NRC R. I. McLean, DNR J. H. Walter, PSC 1
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I
-- Document Control Desk.-
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- i May 31,1991 '
- Page 4 -
bec:
' J. A.Tiernan/A.J.Slusark M. J. Micrnicki W. R. Corcoran -
C.11. Cruse /P. E. Katz
- - R. C DeYoung i
R. M. Douglass/R. F. Ash
! R. P. licibel/I'. N. Pritchett C. P. Johnson
. C C. Lawrence, III/A. R. Thornton R. B. Pond, Jr./S. R. Buxbaum L B. Russell /R. E. Denton/J. R. Iemons W. A.Thornton/E.I.Bauereis G. L Adams A. B. Anuje J. E. Baum
- P. G. Chabot J. J. Connolly G. L Detter -
G. J. Falibota
-J. C Foote L D. Graber D. V. Graf R. C Johnson (2)
W. J. Lippold R E.Nagel B. S. Montgomery R. C L Olson P. A. Pieringer R. H. Waskey, Jr.
L O. Wenger P. S. Furio
. File 60.08.03 File 60.35.06
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