ML20197E137
| ML20197E137 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 05/09/1986 |
| From: | Charemagne Grimes Office of Nuclear Reactor Regulation |
| To: | Opeka J CONNECTICUT YANKEE ATOMIC POWER CO. |
| References | |
| NUDOCS 8605150176 | |
| Download: ML20197E137 (9) | |
Text
'
\\
UNITED STATES
[
3 NUCLEAR REGULATORY COMMISSION I
WASHINGTON, D. C. 20665 May 9, 1986 Docket No.: 50-213 Mr. John F. Opeka, Senior Vice President Nuclear Engineering and Operations Connecticut Yankee Atomic Power Company Post Office Box 270 Hartford, Connecticut 06141-0270
Dear Mr. Opeka:
SUBJECT:
INTEGRATED SAFETY ASSESSMENT PROGRAM TOPICS p
FOR THE HADDAM NECK PLANT In a letter dated July 31, 1985, the staff issued the results of their final screening review of the topics to be addressed in the Integrated Safety Assessment Program (ISAP) for Haddam Neck. Since the issuance of that letter, some topics have been completed, the scope of some topics has changed and several new issues, which may warrant inclusion in the topic list, have been identified by the staff. The purpose of this letter is to present the status of the ISAP topic list, identify three additional topics for evaluation in ISAP and request your verification and comments on the topic list status. to this letter is a list of the ISAP topics that the staff has determined are complete and, therefore, are not required to be evaluated in ISAP. However, pending review of the Haddam Neck Probabilistic Safety Study, new issues concerning diesel generator reliability may warrant evaluation in Topic 1.44.
From the review of the status of the ISAP topics, the staff has detemined that the remainder of the topics are still open and should be evaluated in ISAP. We request that you verify the accuracy of Enclosure 1 and identify any additional topics, such as plant improvement projects, that have been completed or cancelled.
In addition, we recognize, that in the time since our July 31, 1985 letter, the scope of some of the topics may have changed. Therefore, we request that you review the topic list and identify those topics whose scope t.s changed and present details on the change. to this letter is a list of three additional topics that the staff-believes warrant evaluation in ISAP. These topics are a result of recent staff evaluations on the priority of Generic Issues and from changes in the regulations.
In addition to these three new topics, we request that you identify any significant new plant improvement projects initiated since our July 31, 1985 letter, or new issues resulting from your performance of the Haddam Neck PSS.
%[$NN P
~
t Mr. John F. Opeka In order for the staff to proceed with the !!addam Neck ISAP in an expeditious manner, we request that you submit the information requested above, within 30 days of this letter. The reporting and/or recordkeeping requirements contained in this letter affect fewer than ten respondents; therefore, OM8 clearance is not required under P.L.96-511.
Sincerely, To y Christopher I. Grimes, Director Integrated Safety Assessment Project Directorate Division of PWR Licensing - B cc: See Next Page
Enclosures:
As Stated l
Mr. John F. Opeka Connecticut Yankee Atomic Power Company Haddam Neck Plant C C."
Gerald Garfield, Esquire Kevin McCarthy, Director Day, Berry & Howard Radiation Control Unit Counselors at Law Department of Environmental City Place Protection Hartford, Connecticut 06103-3499 State Office Building Hartford, Connecticut 06106 Superintendent Haddam Neck Plant Richard M. Kacich, Supervisor RDF #1 Operating Nuclear Plant Licensing Post Office Box 127E Northeast Utilities Service Company East Hampton, Connecticut 06424 Post Office Box 270 Hartford, Connecticut 06141-0270 Edward J. Mroczka Vice President, Nuclear Operations Northeast Utilities Service Company y
Post Office Box 270 Hartford, Connecticut 06141-0270 Scard of Selectmen Town Hall Haddam, Connecticut 06103 State of Connecticut Office of Policy and Management ATTN: Under Secretary Energy f
Division 80 Washington Street i
Hartford, Connecticut 06106
{
Resident Inspector Haddam Neck Nuclear Power Station c/o U.S. NRC East Haddam Post Office East Haddam, Connecticut 06423 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406 1
Completed Haddam Neck ISAP Topics Topic No.
Title Reference l,
1.15 FDSA Update 11/22/85 Exemption 1.29 Service Water System 04/10/86 SER 1.33 Items 3.1.1 & 2 - Post Maintenance 02/21/86 SER Testing J
1.34 Item 3.1.3 - Post Maintenance 10/16/85 SER s
Testing TS 1.35 Item 4.1 - Reactor Trip System 02/2.1./86 SER Reliability i
1.37 Items 3.2.1 & 2 - Post Maintenance 02/21/86 SER Testing Procedures i
1.38 Item 3.2.3 - Post Maintenance 10/16/85 SER Testing TS i
1.41 Item 4.5.1 - Reactor System 02/21/86 SER f
Functional Testing i
1.44 Diesel Generator Reliability 09/06/85 Staff memo
1 Additional Topics to be Considered in the Haddam Neck ISAP Topic No.
Title Reference 1.59 Additional Low Temperature NUREG-0933: GI-94 Overpressure Protection for Light Water Reactors j
1.60 RCS/RHR Suction Line Valve NUREG-0033: GI-99 Interlock in PWRs 1.61 Pressurized Thermal Shock 10 CFR 50.61 i
9 L
1 l
l
0 Tepic 1.59 Additional Low Temperature Overpressure Protection for Light Water Reactors Low temperature overpressurization (LTOP) was originally identified as USI A-26 and was resolved in September 1978 by a revision to Standard Review Plan Section 5.2.
The resolution affected all PWRs and required PWR licensees to implement procedures to reduce the potential for overpressure events and make equipment modifications to mitigate such events. From 1979 to July 1983, 12 pressure transients were reported. The continuation of overpressure transient events may indicate potential weaknesses in the present criteria or its implementation that may warrant further consideration.
Resolution of this issue may include some or all of the following measures:
.i (a) Amend the STS and the SRP to require each licensee to identify the criteria used to determine if and when the LT0P system setpoints s
need to be adjusted to account for the irradiation-induced embrittle-ment of the reactor vessel.
(b) Make more use of the relief valves in the RHR for LTOP by raising j
the setpoint for the auto-closure of the isolation valves, y
9 (c) Amend the STS to allow no plant operation in the " water solid" condition with either train of the LTOP system out of service.
t (d) Amend the STS to allow no plant to operate in the " water solid" l
condition with an SI pump in service, l
1 i
(e) Require the LTOP system to be fully safety grade.
I (f)
Require all operating reactors to upgrade their TS to the STS for LTOPs.
1 l
I Tcpic 1.60 RCS/RHR Suction Line Valve Interlock on PWRs i)
Interlocks are provided to assure that there is a double barrier (two closed valves) between the RCS and RHR systems when a plant is at normal operating conditions, i.e., pressurized and not in the RHR cooling mode.
b the W;stinghouse design, 2 interlock channels are provided such that I channel is used to interlock the operation of one RHR suction valve and the other channel,is used for the other valve. Since the relays used for this interlock are deenergized to initiate valve closure, a loss of the instrument bus used for either channel will result in a loss of RHR cooling due to inadvertent closure of one of the suction valves.
In the RHR cooling mode, such closure gives rise to the potential for RHR pump damage and loss of decay heat removal by the RHR system.
)
R: solution of this issue may include some or all of the following measures:
(a) Review and document the design basis for the RHR suction valve interlock.
i (b) Develop interim operating procedures until changes to the logic l
and control for the RHR system can be implemented.
t (c) Change the logic configuration that controls the valves from a C
i one-of-one configuration to a two-of-two configuration.
Improvements l
in detecting and alarming of the loss of RHR coolant flow would be made.
(d) Changes to the plants' TS.
Topic 1.61 Pressurized Thermal Shock As required by 10 CFR 50.61, " Fracture Toughness Requirements for Protection Against Pressurized Thermal Shock Events," which went into effect July 23, 1985 the licensees of PWRs should submit projected values of RT of the PTS reactor vessel beltline materials from the time of the submittal until the expiration date of the license. This information is to be updated whenever core loadings, surveillance requirements or other inforn.ation indicated a significant change in the ;:rojected values. Also, for those plants which the value of RT is projected to exceed the screening criteria, the licensee PTS must develop and implement a flux reduction program if practical, or modifications to equipment to prevent potential reactor vessel failures as a result of pressurized thermal shock events.
4 l
J t
I a
mm.
r
-o o May 9, 1986 50 7-l3 Mr. John F. Opeka In order for the staff to proceed with the Haddam Neck ISAP in an expeditious manner, we request that you submit the information requested above, within 30 days of this letter. The reporting and/or recordkeeping requirements contained in this letter affect fewer than ten respondents; therefore, OMB clearance is not required under P.L.96-511.
Sincerely, Original signed by Christopher I. Grimes Christopher I. Grimes, Director Integrated Safety Assessment Project Directorate Division of PWR Licensing - B cc: See Next Page
Enclosures:
As Stated DJSTRIBUTION A ocket File NRC PDR Local PDR ISAP Reading NSIC FMiraglia OELD EJordan l
'BGrimes MBoyle EMcKenna PAnderson FAkstulewicz
.ACRS (10)
CGrimes AWang ISAPD:DPL-B ISAPD: PL-B ISAPD:DPL-B ISAPD:DPL-B ISAPD:DP MBoyle:lt AWang N FAkstulewicz PAnderson CGrimes 06/Q/86 Oj/ 7/86 OJ/}/86 Of/4 /86 05/9,/86