ML20133C439
| ML20133C439 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 12/27/1996 |
| From: | Stephen Dembek NRC (Affiliation Not Assigned) |
| To: | Harpster T, Kenyon B NORTHEAST UTILITIES SERVICE CO. |
| References | |
| TAC-M97181, NUDOCS 9701070186 | |
| Download: ML20133C439 (4) | |
Text
_ _ _. _ _. _ _
e -
December 27, 1996 i
Mr.:B. D. Kenyon DISTRIBUTION President - Nuclear Group Docket File' PMcKee Northeast Utilities Service Company PUBLIC SDembek i
c/o Mr. Terry L. Harpster _
SP0 Reading LBerry Director - Nuclear Licensing Services ACRS MFairtile
)
P.O. Box 128 JRogge, RI OGC Waterford, CT 06385 MMitchell, EMCB
SUBJECT:
REQUEST'FOR ADDITIONAL INFORMATION (TAC NO. M97181) i
')
Dear Mr. Kenyon:
The staff of the Office of Nuclear Reactor Regulation (NRR) was asked by Region I to examine the conditions associated with a July 1994 event in which an isolated reactor coolant loop apparently reached 1000 psig and 106 'F.
i This event came to the attention of the regional staff as a result of the events during the August 1996 plant shutdown. The NRR staff has determined that additional information from your staff is necessary to assess Region I's j
\\
concerns. The staff realizes that the joint owners of Haddam Neck have
'l
. decided to decommission the facility. However, the staff believes this issue has potential generic implications and we appreciate your cooperation.
Please respond to this request for additional information within 30 days of receipt of this letter.
Sincerely, Original signed by:
Stephen Dembek, Project Manager Special Projects Office - Licensing W\\
Office of Nuclear Reactor Regulation Docket No. 50-213
Enclosure:
Request for Additional Information cc w/ encl:
See next page
\\
\\
DOCUMENT NAME: G:\\DEMBEK\\M97181.RAI 0FFICIAL RECORD COPY Ta seeelve e copy of this decennent indesse in the ben: "C" = Copy without ottachment/ enclosure
- E' = Copy with attachrnent/ enclosure "N" = No copy 0FFICE SPO-L:PM.
lE SP0:LA B, 1, SP0-L:DD. J l
l NAME SDembelc//R LBerry MI'J PMcKee 4 0 PN fM
(
DATE 12Dfo/96-12/ 8 /96 12/D/96'
)
1 9701070186 961227 PDR.ADOCK 05000213 1
SC Hg C9 LIER CDP.
[ pong #*,
- \\
ji UNITED STATES j
NUCLEAR REGULATORY COMMISSION t
WASHINGTON, D.C. 20686-0001
\\..,+/
4 December 27, 1996 Mr. B. D. Kenyon President - Nuclear Group Northeast Utilities Service Company c/o Mr. Terry L. Harpster Director - Nuclear Licensing Services P.O. Box 128 Waterford, CT 06385
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION (TAC NO. M97181)
Dear Mr. Kenyon:
I The staff of the Jffice of Nuclear Reactor Regulation (NRR) was asked by Region I to examine the conditions associated with a July 1994 event in which an isolated reactor ' coolant loop apparently reached 1000 psig and 106 "F.
This event came to the attention of the regional staff as a result of the events during the August 1996 plant shutdown. The NRR staff has determined that additional information from your staff is necessary to assess Region I's concerns.
The staff realizes that the joint owners of Haddam Neck have decided to decommission the facility. However, the staff believes this issue has potential generic implications and we appreciate your cooperation.
Please respond to this request for additional information within 30 days of receipt of this letter.
Sincerely, Stephen Dembek, Project Manager Special Projects Office - Licensing Office of Nuclear Reactor Regulation Docket No. 50-213
Enclosure:
Request for Ado ~ tional Information cc w/ encl:
See next page
j 1
Northeast Utilities Service Company Haddam Neck Plant cc:
Lillian M. Cuoco, Esq.
Regional Administrator Senior Nuclear Counsel Region I Northeast Utilities Service Company U.S. Nuclear Regulatory Commission P.O. Box 270 475 Allendale Road Hartford, CT 06141-0270 King of Prussia, PA 19406 Mr. Kevin T. A. McCarthy, Director Board of Selectmen Monitoring and Radiation Division Town Office Building Department of Environmental Protection Haddam, CT 06438 79 Elm Street Hartford, CT 06106-5127 Resident Inspector Haddam Neck Plant Mr. Allan Johanson, Assistant Director c/o U.S. Nuclear Regulatory Commission Office r* Policy and Management 361 Injun Hollow Road Polic) be,clopment and Planning Division East Hampton, CT 06424-3099 80 Washington Street Hartford, CT 06106 Mr. James S. Robinson Manager, Nuclear Investments and Mr. J. J. LaPlatney Administration Haddam Neck Unit Director New England Power Company Connecticut Yankee Atomic Power Company 25 Research Drive 362 Injun Hollow Road Westborough, MA 01582 East Hampton, CT 06424-3099 Mr. G. P. van Noordennen Mr. F. C. Rothen Manager - Nuclear Licensing Vice President - Work Services Northeast Utilities Service Company Northeast Utilities Service Company 362 Injun Hollow Road P. O. Box 128 East Hampton, Connecticut 06424-3099 Waterford, CT 06385 Mr. D. M. Goebel Vice President - Nuclear Oversight Ncrtheast Utilities Service Company P. O. Box 128 Waterford, Connecticut 06385 Mr. J. K. Thayer Recovery Officer, Nuclear Engineering and Support Northeast Utilities Service Company P. O. Box 128 Waterford, Connecticut 06385 Mr. T. C. Feigenbaum Executive Vice President and Chief Nuclear Officer Northeast Utilities Service Company P. O. Box 128 Waterford, Connecticut 06385 l
(
j REQUEST FOR ADDITIONAL INFORMATION 1)
Explain the evolution of the July 1994 event.
In particular, note what d
the RCS and secondary side conditions were at the time the loop isolation valves were closed, what caused the temperature and pressure
= to reach their eventual values of 1000 psig and 106 *F, and what factors (if any) limited the pressure increase.
2)
State any operational restraints (i.e. unacceptable pressure / temperature i
regimes or relief valve capability) which may have been established by the design code of record for all ferritic components of an isolated j
reactor coolant loop. Show that the conditions (1000 psi at a temperature of 106 *F) associated with the July 1994 event are j
consistent with these design considerations.
3)
Demonstrate that the calculations performed to analyze-the July 1994 event by the methods of ASME Section III (or Section XI) Appendix G are correct.
Provide additional detail on the geometry of steam generator channel head including head diameters and wall thicknesses, the results i
of the channel head stress analysis, the assumed flaw orientation and i
size, the material properties for the ferritic materials in the channel head, and the loading conditions (pressure and temperature) during the July 1994 event. This information will permit the staff to j
indapendently assess the significance of the event.
I 4)
State any corrective actions that were taken as a result of the July i
1994 event to prevent conditions which could lead to nonductile failure j~
of the reactor coolant loop when the loops are isolated.
Based upon the analysis performed by Westinghouse for. Northeast Utilities, the staff j
expects that the licensee would have taken corrective actions to ensure that pressure / temperature conditions would not occur which could challenge the integrity of.any loop in a subsequent event.
However, it 2
appears from the information received to date that no precautions against overpressurization were in place during the August 1996 event.
5)
Provide information on any other events of this type that may have i
occurred previously at Haddam Neck or other pressurize water reactors j
with loop isolation capability.
i l
Enclosure
_ _