ML20041C258
| ML20041C258 | |
| Person / Time | |
|---|---|
| Site: | Zimmer |
| Issue date: | 02/04/1982 |
| From: | Tedesco R Office of Nuclear Reactor Regulation |
| To: | Borgmann E CINCINNATI GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8202260413 | |
| Download: ML20041C258 (4) | |
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- LB#1 Reading TERA FEB 4 1982 DEisenhut NRC/PDR BJYoungblood L/PDR Docket Ho.:
50-358 RLTedesco ACRS (16)
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Mr. Earl A. Borgnann JKramer Senior Vice President g
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Cincinnati, Ohio 45201 MRushbrook
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Dear Mr. Borgnann:
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Interlocks Dependent on Pressure Signals for Valves Corjnecting AS M
the Low Pressure ECCS with the Reactor Coolant Systen %'(Lgv During our review of the Technical Specifications for a BWR 5/ Mark II l
facility, we noted that the permissive for opening the motor-operated valves in the injection Ifnes of the low nressure energency core cooling systems (ECCS) is derived from a signal based on the pressure differential across these valves. The value of differential pressure contained in the Technical Specifications would pemit these valves to be operated wnfle the reactor coolant pressure was greater than the design pressure of the low pressure ECCS for sone types of events. This in turn, could result in over-pressurization of the low pressure ECCS.
The specific design for pressure isolation valves in the low pressure ECCS injection lines which prompts our concern consists of a testable check valve in series with a nomally closed, motor-operated valve.
In the event of a signal indicating a loss-of-coolant accident (LOCA), the low pressure ECCS pumps are started. The motor-operated injection valves are also signaled to ooen but require a permissive signal dependent on a pressure measure-4 nent before an interlock is released.
If this pressure dependent signal is based on a pressure differential across the notor-operated valves, the low pressure ECCS ptraps could develop sufficient pressure on the low pres-sure side to satisfy the permissive and open the valve even though the reactor coolant pressure was still close to its operating pressure. This would be the sequence for'small-break LOCAs using the specific design described above. ~ Other sequences such as an-inadvertent ECCS actuation could also lead to an overpressurization of the low nressure ECCS.
The redundant check valve in series with a motor-operated valve which is open should, under normal' conditions, prevent over-pressurization of the low pressure ECC5 for the conditions described above. However, there have been a nuaber of check valve failures in operating reactors in lines connecting high and low pressure systens. Based on the information available to us, we nust anticipate that there will be additional check valve failures.
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NRC FORM 318 00-80) NRCM ONO OFFIClAL RECORD COPY-usamgui-mno
2 In light of the foregoing discussion, it is our position that redundant protection against overpressurization of all low pressure ECCS be provided.
This may be acconplished by having an interlock on all motor-operated valves which are in series with a single check valve and which interface between the reactor coolant pressure and the low pressure ECCS. This interlock will recaain in place until a signal is received indicating that the reactor coolant pressure is lower than the design pressures of the various low pressure ECCS and should restrict both aanual and automatic in.jection valve operation under this condition.
Our position on this matter is consistent with the first provision presentea in Section 6.3 of the Standard Reveiv Plan (SRP).
Alternatively, the second and third provisions in Section 6.3 of the SRP would also satisfy our concerns in this matter.
We have looked at the system descriotion of your plant and are unable to determine clearly whether the interlocks on the motor-operated injection valves of the low pressure ECCS satisfy our position on this riatter.
Accordingly, we request that you sutnit the following additional infomation:
a 1.
Indicate the number and type of injection valves on each of the low pressure ECCS irtjection lines.
2.
For each notor-operated injection valve, indicate the number and types of interlocks, including a description of the pemissives to be satisfied before these valves can be either nanually or auttnatically operated. This description should clearly state u'iether the interlocks prevent operation of the motor-operated valves until the reactor coolant pressure is below the design pressure of the affected ECCS.
We will consider this matter as an open item on your pending application for an operating license until you provide assurance that you satisfy our position on this matter.
If you choose not to adopt one of the provisions contained in Section 6.3 of the SRP, provide an alternate design which satisfies our concerns on this natter including a justification for your design.
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NRC FORM 318 (10-80) NRCM ONO -
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, lie request that you provide, within 30 days of the receipt of this letter, a date when you will. respond to our request.
If you have any questions on this natter, please contact the Project Manager, I. Peltier, at (301) 492-7038.
Si ncerely,
@ginal Sggn d by
@ M y Tedesca Robert L. Tedesco, Assistant Director for Licensing Division of Licensing cc:
See next page
'The reporting and/or recordkeeping requirenents cont 11ned in this le~tter affoct ferter thu t,cn respondents ;
therefore, Otf3 clearance is not required under P.L.90-511.
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Mr. Earl A. Borgmann Senior Vice President Cincinnati Gas & Electric Company
~ Post Office Box 960 Cincinnati, Ohio 45201 cc: Troy B. Conner, Jr., Esq.
Deborah Faber Webb Conner, Moore & Corber 7967 Alexandria Pike 1747 Pennsylvania Avenue, N.W.
Alexandria, Kentucky 41001 Washington, D. C.
20006 Andrew B. Dennison, Esq.
Mr. William J. Moran 200 Main Street General Counsel Batavia, Ohio 45103 Cincinnati Gas & Electric Company Post Office Box 960 George E. Pattison, Esq.
Cincinnati, Ohio 45201 Clermont County Prosecuting Attorney 462 Main Street Mr. Samuel H. Porter Batavia, Ohio 45103 Porter, Wright, Morris & Arthur 37 West Broad Street Mr. Waldman Christianson Columbus, Ohio 43215 Resident Inspector /Zimmer RFD 1, Post.0ffice Box 2021 Mr. James D. Flynn, Manager U. S. Route 52 Licensing Environmental Affairs Moscow, Ohio 45153 Cincinnati Gas & Electric Company Post Office Box 960 Mr. John Youkilis Cincinnati, Ohio 45201 Office of the Honorable William Gradison David Martin, Esq.
United States House of Representatives Office of the Attorney General Washington, D. C.
20515 209 St. Clair Street First Floor
~
Timothy S. Hogan, Jr., Chairman Frankfort, Kentucky 40601 Board of Commissioners 50 Market Street, Clermont County James H. Feldman, Jr., isq.
Batavia, Ohio 45103 216 East 9th Street-Cincinnati, Ohio 45220 Lawrence R. Fisse, Esq.
Assistant Prosecuting Attorney W. Peter Heile, Esq.
462 Main Street Assistant City Solicitor Batavia, Ohio 45103-Room 214, City Hall Cincinnati, Ohio 45220 Mr. James G. Keepler U. S. NRC, Region III John D. Woliver,' Esq.
799 Roosevelt Road Legal Aid. Security Glen Ellyn, Illinois 60137 Post Office Box #47 550 Kilgore Street Batavia, Ohio 45103
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