ML20235T475
| ML20235T475 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 03/02/1989 |
| From: | Chandu Patel Office of Nuclear Reactor Regulation |
| To: | Bliss H COMMONWEALTH EDISON CO. |
| References | |
| GL-88-17, TAC-69795, TAC-69796, NUDOCS 8903080303 | |
| Download: ML20235T475 (5) | |
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iMr. Henry lE. Bliss'
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H Nuclear: Licensing Mansper.
- Commonwealth Edison Company Post Office
- Box 767
' Chicago, Illinois 60690
Dear Mr.:
Bliss:
'SUBJECTii COMMENTS ON THE COMMONWEALTH EDISON COMPANY RESPONSE TO GENERIC
' LETTER 88-17 FOR-ZION STATION UNITS I AND 2-(TAC NOS; 69795 AND6 69796)
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.The NRCLstaff has reviewed your submittal dated December 30, 1988, in response
.to Generic Letter 88-17, describing the expeditious ^ actions taken for< reducing
- the risk from a. potential' loss of decay heat removal event at Zion Station-
~ Units 1 and 2.. e find that your response meets;the intent of the generic W
. letter with respect to expeditious-actions.= However, as your response was.
brief,: the staff was. unable to' review it in any great detail. Our comments on your submittal-are enclosed.. You may wish'to consider.these comments in orcer
.to. assure yourself. about, the adequacy of your actions..
o As' you are aware',:the expeditious actions are an interim measure to achieve an insediate reduction in risk ~ associated with reduced inventory operation,.and
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these will be supplemented and in some cases replaced by programmed enhance-ments. You are not expected to respond to:our coments at this time. However,.
we intend to audit your expeditious actions as~well as your. programed enhancements in the future. Our audit may. cover some.of the p61nts discussed'
.in the enclosure.
Sincerely,
/5, Chandu P. Patel, Project Manager Project Directorate III-2 Division of. Reactor Projects.III -
C" IV, V and Special Projects' So
Enclosure:
As stated.
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'Mr.' Henry'.E. BlissL Nuclear Licensing Manager
,J Commonwealth Edison Company =
JPost Office Box 767.
Chicago,. Illinois 60690
Dear.Mr. Bliss:
SUBJECT:
COMMENTS ON THE COMMONWEALTH EDISON COMPANY RESPONSE TO GENERIC D
LETTER 88-17 FOR ZION STATION UNITS.1 AND 2.(TAC NOS. 69795 1.ND 69796):
The NRC staff-has reviewed your submittal. dated December 30, 1988, in response
' to Generic Letter 88-17, describing the expeditious actions taken for: reducing the risk from.a potential loss of decay heat removal event at Zion Station
' Units 1 and 2. -We find that your response meets the intent of the' generic' letter with' respect to expeditious actions. However, as your response was
.brief, the staff was unable to review it in any great detail. Our comments on your' submittal are enclosed. You may wish to consider these-comments.in order-to' assure yourself about the adequacy of your actions.
As you are aware, the expeditious actions are an -interim measure to achieve an
-immediate reduct, ion in risk associated with reduced inventory operation, and these.will be supplemented and in some cases replaced by programmed enhance-
- ments. You are not expected.to respond to our; comments at this time. However,-
we' intend to audit ~your expeditious actions as well as your programmed enhancements'in the future. Our audit. may cover some of the points discussed in the enclosure.
Sincerely,
& $Ph Chandu P. Patel, Project Manager Project Directorate III-2 Division of Reactor Projects III -
IV, Y and Special Projects
Enclosure:
As stated cc: See next page m
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Mr'. Henry E. Bliss.
Zion Nuclear Power Station 1
commonwealth Edison Company e
_ Units 1,and 2 cc:
Robert J. Vollen, Esquire Mr. Michael C. Parker, Chief...
109 North Dearborn Street' Division of Engineering Chicago, Illinois 60602..
Illinois Department of Nuclearc Safetyi Dr. Cecil Lue-Hing-
- 1035 Outer; Park Drive, 5th Floor Director of Research and Development Springfield, Illinois 62704-Metropolitan Sanitary District of Greater Chicago 100 East Erie Street Chicago, Illinois 60611 _.
-Phillip Steptoe, Esq..
Sidley and Austin
.0ne First National Plaza Chicago, Illinois 60603 Mayor.of Zion Zion, Illinois 60099 Illinoi -Department of. Nuclear Safety ATTN: Manager, Nuclear Facility Safety 1035 Outer Park Drive', 5th Floor Springfield, Illinois 62704-U.S.. Nuclear Regulatory Commission Resident Inspectors Office
-105 Shiloh Blvd.
Zion, Illinois.60099 Regional Administrator, Region III
~ U.S. Nuclear Regulatory Commission 799 Roosevelt Road, Bldg. f4 Glen Ellyn, Illinois 60137 i
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l ENCLOSURE 1
COMMENTS ON THE COMMONWEALTH EDISON RESPONSE TO GENERIC LETTER 88-17 FOR THE ZION STATION UNITS 1 AND 2 LOSS OF DECAY HEAT REMOVAL The NRC staff has reviewed the submittal dated December 30, 1988 from Commonwealth Edison in response to Generic Letter 88-17 and have the following comments:
1.
You mention discussion of the Diablo Canyon event with operations personnel and training for specific mid-loop operation and cooldown/
draindown with your staff. However, it is not specifically stated that maintenance personnel are also included. The item was intended to include all personnel who can affect reduced inventory operation.
2.
You reference many of the responses as limited to " intentionally" entering a reduced inventory condition. We assume your meaning is for any entry into et reduced inventory condition that is deliberate on the part of the operators.
Hence, an entry for the purpose of repairing an unanticipated reactor coolant pump seal failure would be an intentional entry. An entry due to a loss of coolant accident would be unintentional.
3.
You reference the containment closure times of 30 minutes and 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and indicate that you intend "to utilize the results of analysis that extends the time required for containment closure...". This is acceptable.
4.
Your discussion about containment closure is cursory and no information is provided regarding how you will keep track of and control the many potential openings which may have to be closed simultaneously. We assume your procedures and administrative controls will address this topic.
5.
Reference to level indication being "close enough" if within four inches is undesirable. Small (less than four inches) changes in level between two measurement systems can make the difference between acceptable 1
operation and loss of RHR. Also, two level instruments measuring at different locations may well sense different levels. The accuracy and I
reliability of the level instrumentation may need more thought.
6.
Walking the tygon tube following installation to verify lack of kinks or loop seals is good. Experience shows that periodic walkdowns are needed after installation. We recommend daily walkdowns when the tygon tube is in use, with an additional walkdown immediately prior to its being placed in use.
7.
Your use of gravity feed depends upon an adequate vent path as you correctly state. You did not mention the vent size or otherwise indicate what you have in mind. Since a pressurization of only a few psi may
- 7.,...
2-prevent gravity feed, you should carefully address this situation. We note that relatively large hot side openings in the RCS, such as a pressurizer manway, can still lead to a pressure of several psi. The large steam flow rate in combination with flow restrictions in the surge line er.d lower pressurizer hardware rey lead to pressurization. Calculations should be performed to verify the effectiveness of the opening.
8.
You appear to be attempting to work within existing technical s)ecifications in meeting the generic letter recommendations. We note t1at technical specification changes will be considered if existing specifications are overly restrictive.
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