ML20030A903
Text
-
9-l+I 8i Gentlemen:
The enclosed IE Information Notice No. 81 21, " Potential Loss of Direct Access to Ultimate Heat Sink' is forwarded to you for information. No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely, Boyce H. Grier Director
Enclosure:
IE Information Notice No. 81-21 with 1 attachment CONTACT:
S. D. Ebneter (215-337-5283) t I
l l
pv;?/
0
_e
\\
w k\\
8107290170 810721 h\\
DR ADOCK 03000003 PDR
.. m
E e
LIST OF HOLDERS OF NUCLEAR POWER REACTOR OPERATING LICENSES AND CONSTRUCTIOF PERMITS RECEIVING IE INFORMATION NOTICE NO. 81-21 Baltimore Gas and Electric Company Docket Nos. 50-317 ATTN: Mr. A. E. Lundvall, Jr.
50-318 Vice President, Supply P. O. Box 1475 Baltimore, Maryland 21203 Boston Edison Company M/C Nuclear Docket No. 50-293 ATTN: Mr. A. V. Morisi Nuclear Operations Support Manager 800 Boylston Street Boston, Massachusetts 02199 Connecticut Yankee Atomic Power Company Docket No. 50-213 ATTN: Mr. W. G. Counsil Vice President - Nuclear Engineering and Operations P. O. Box 270 Hartford, Connecticut 06101 Consolidated Edison Company of Docket Nos. 50-03 New York, Inc.
50-247 ATTN: Mr. John D. O'Toole Vice President - Nuclear Engineering and Quality Assurance 4 Irving Place New York, New York 10003 Duquesne Light Company Docket No. 50-334 ATTN: Mr. J. J. Carey Vice President Nuclear Division P. O. Box 4 Shippingport, Pennsylvania 15077 Jersey Central Power and Light Company Docket No. 50-219 ATTN: Mr. Ivan R. Finfrock, Jr.
I Vice President Oyster Creek Nuclear Generating Station P. O. Box 388 Forked River, New Jersey 08731 7* = - 't w
e>
=
e.w.
e w
7 w
-+
y
2 Maine Yankee Atomic Power Company Docket No. 50-309 ATTN: Mr. Robert H. Groce Senior Engineer-Licens,ng 1671 Worcester Road Framingham, Massachusetts 01701 Metropolitan Edison Company Docket No. 50-289 ATTN:
Mr. H. D. Hukill Vice President and Director of TMI-1 P. O. Box 480 Middletown, Pennsylvania 17057 Metropolitan Edison Company Docket No. 50-320 ATTN:
Mr. G. K. Hovey Vice President and Director of TMI-2 P. O. Box 480 Middletown, Pennsylvania 17057 Niagara Mohawk Power Corporation Docket No. 50-220 ATTN:
Mr. T. E. Lempges Vice President Nuclear Generation 300 Erie Boulevard West Syracuse, New York 13202 Northeast Nuclear Energy Company Docket Nos. 50-336 ATTN:
Mr. W. G. Counsil 50-245 Senior Vice President - Nuclear 50-423 Engineering and Operations P. O. Box 270 Hartford, Connecticut 06101 Philadelphia Electric Company Docket Nos. 50-277 ATTN:
Mr. S. L. Daltroff 50-278 Vice President Electric Production 2301 Market Street Philadelphia, Pennsylvania 19101 Power Authority of the State of New York Docket No. 50-286 Indian Paint. 3 Nuclear Power Plant ATTN:
Mr. J. C. Brons Resident Manager P. O. Box 215 Buchanan, New York 10511
3 Power Authority of the State of New York Docket No. 50-333 James A. FitzPatrick Nuclear Power Plant ATTN: Mr. R. J. Pasternak Resident Manager P. O. Box 41 Lycoming, New York 13093 Public Service Electric and Gas Company Docket Nos. 50-272 ATTN: Mr. F. W. Schneider 50-311 Vice President - Production 80 Park Plaza - 15A Newark, New Jersey 07101 Rochester Gas and Electric Corporation Docket No. 50-244 ATTN:
Mr. John E. Maier Vice President Electric and Steam Production 89 East Avenue Rochester, New York 14649 Vermont Yankee Nuclear Power Corporation Docket No. 50-271 ATTN: Mr. Robert L. Smith Licensing Engineer 1671 Worcester Road Framingham, Massachusetts 01701 Yankee Atomic Electric Company Docket No. 50-29 ATTN: Mr. James A. Kay Senior Engineer-Licensing 1671 Worcester Road Framingham, Massachusetts 01701 Duquesne Light Company Docket No. 50-412 ATTN: Mr. E. J. Woolever Vice President 435 Sixth Avenue Pittsburgh, Pennsylvania 15219 Jersey Central Power & Light Company Docket No. 50-363 ATTN: Mr. I. R. Finfrock, Jr.
Vice President 260 Cherry Hill Road Parsippany, New Jersey 07054 Long Island Lighting Company Docket No. 50-322 ATTN: Mr. M. S. Pollock Vice President - Nuclear 175 East Old Country Road Hicksville, New York 11801 i
4 Niagara Mohawk Power Corporation Docket No. 50-410 ATTN: Mr. Gerald K. Rhode Vice President System Project Management c/o Miss Catherine R. Seibert 300 Erie Boulevard, West Syracuse, NY 13202 Pennsylvania Power & Light Company Docket Nos. 50-387 ATTN:
Mr. Norman W. Curtis 50-388 Vice President Engineering and Construction - Nuclear 2 North Ninth Street Allentown, Pennsylvania 18101 Philadelphia Electric Company
' locket Nos. 50-352 ATTN:
Mr. John S. Kemper 50-353 Vice President Engineering and Research 2301 Market Street Philadelphia, Pennsylvania 19101 Public Service Electric & Gas Company Docket Nos. 50-354 ATTN:
Mr. T. J. Martin 50-355 Vice President Engineering and Construction 80 Park Plaza - 17C Newark, New Jersey 07101 Public Service Company of New Hampshire Docket Nos. 50-443 ATTN:
Mr. W. C. Tallman 50-444 Chairman and Chief Executive Officer 1000 Elm Street Manchester, New Hampshire 03105 a
,7-
.-w,-
a--
e-e-*-
.-m-
- ,e-
-4 4
,- +
m
o.
N SSTN No.:
6835 o
cc Accasdon No. :
2 N
UNITED STATES M 1A ~ S o
l NUCLEAR REGULATORY COMMISSION
~
Q@
D OFFICE OF INSPECTION AND ENFORCEMENT
(;s WASHINGTON, D.C.
20555
- ^.J
~
"U i July 21, 1981 I
IE INFORMATION NOTICE NO. 81-21:
P0TENTIAL LOSS OF DIRECT ACCESS TO ULTIMATE HEAT SINK Description of Circumstances:
IE Bulletin 81-03, issued April 10, 1981, requested licensees to take certain actions to prevent and detect flow blockage caused by Asiatic clams and mussels.
Since then, one event at San Onofre Unit 1 and two events at the Brunswick Station have indicated that situations not explicity discussed in Bulletin 81-03 may occur and result in a loss of direct access to the ultimate heat sink.
These situations are:
1.
Debris from shell fish other than Asiatic clams and mussels may cause flow blockage problems essentially identical to those described in the bulletir.
2.
Flow blockage in heat exchangers can cause high pressure drops that, in turn, deform baffles, allowing bypass flow and reducing the pressure drop to near normal values.
Once this occurs, heat exchanger flow blockage may not be detectable by pressure drop measurements.
3.
Change in operating conditions.
(A lengtny outage with no flow through seawater systems appears to have permitted a buildup of mussels in systems where previous periodic inspections over more than a ten year period showed no appreciable problem.)
We are currently reviewing these events and the responses of the licensees to IEB 81-03. We expect licensees are performing the actions specified in IEB 81-03 such that cooling water flow blockage from any shell fish is prevented or minimized, and is detected before safety components become inoperable.
j On June 9,1981, San Onofre Nuclear Generating Station Unit No. I reported that as a result of a low saltwater coolant flow rate indication and an apparent need for valve maintenance, a piping elbow on the saltwater discharge line from component cooling heat exchanger E-20A was removed by the licensee just upst. ream of butterfly valve 12"-50-415 to permit visual inspection.
An I
examination revealed growth of some form of sea mollusk such that the cross-sectional diameter of the piping was reduced.
The movement of the butterfly valve was impaired and some blockage of the heat exchanger tube sheet had occurred.
Evaluation of the event at San Onofre is continuing.
However, the prolonged (since April 1980) reactor shutdown for refueling and steam generator repair is believed to have caused the problem since previous rcutine inspections conducted since 1968 at 18 month intervals ha not revealed mollusks during normal periods of opera. ion.
h f gpu 'l4' DUPE lb\\
'Se I..
IN 81-21 July 21, 1981 Page 2 of 3 Two events at Brunswick involved service water flow blockage and inoperability of redundant residual heat removal (RHR) heat exchangers, primarily due to oyster shells blocking the service water flow through the heat exchanger tubes.
On April 25, 1981, at Brunswick Unit 1, while in cold shutdown during a maintenance outage, the normal decay heat removal system was lost when the single RHR heat excharger in service failed.
The failure occurred when the starting of a second RHR service water pump caused the failure of a baffle in the waterbox of the RHR heat exchanger, allowing cooling water to bypass the tube bundle.
The heat exchanger is U-tube type, with the service water inlet and outlet separated by a baffle.
The copper-nickel baffle which was welded to the copper-nickel tubesheet deflected and failed when increased pressure was produced by starting the second service water pump.
The redund:nt
~ heat exchanger was inoperable due to maintenance in progress to repair its baffle which had previously deflected (LER 1-81-32, dated May 19, 1981).
The licensee promptly established an alternate heat removal alignment using the spent fuel pool pumps and heat exchangers.
As a result of the problems discovered with Unit 1 RHR heat exchangers, a special inspection of the Unit 2 RHR heat exchangers was performed while Unit 2 was at pcwer.
Examination of RHR heat exchanger 2A using ultrasonic techniques indicated no baffle displacement but flow testing indicated an excessive pressure drop across the heat exchanger.
This heat exchanger was declared inoperable.
Examination of the 2B RHR heat exchanger using ultrasonic and differential pressure measurements indicated that the baf fle plate was damaged.
The licensee initiated a shutdown using the 2A RHR heat exchanger at reduced capacity (LER 2-81-49, dated May 20, 1981).
The failure of the baffle was attributed to excessive differential pressure caused by blockage of the heat exchanger tubes.
The blockage was caused by the shells of oysters with minor amounts of other types of shells which were swept into the heads of the heat exchangers since they are the icw point in the service water system.
The shells resulted from an infestation of oysters growing primarily in the 30" header from the intake structure to the reactor building.
As the oysters died their upper shells detached and were swept into the RHR heat exchangers where they collected.
Small amounts of shells were found in other heat exchangers cooled by service water.
Most of the operating BWRs use U-tube heat exchangers in the RHR system.
(The heat exchangers used at Brunswick were manufactured by perflex Corporation and are identified as type CEU, size 52-8-144.)
The observed failures raise a question on the adequacy of the baffle design to withstand differential pressures that could reasonably be expected during long term post accident operation.
However, it should be noted that since the baffles at Brunswick are solid copper-nickel as are the tubesheets and the water boxes are copper-nickel clad, the strength of the baffles and the baffle welds is somewhat less than similar heat exchangers made from carbon steel.
Therefore, heat exchangers in other BWR's may be able to tolerate higher differential pressure than that at Brunswick without baffle deflection.
(Brunswick opted for copper-nickel due to its high corrosion and fouling resistance in a salt water environment.)
~
m a
IN 81-21 July 21, 1981 Page 3 of 3 The use of differential pressure (dp) sensing between inlet and outlet to determine heat exchanger operability should consider that baffle failure could give an acceptable dp and flow indications and thereby mask incapability for heat removal.
Hcwever, it is noted that shell blockage in a single pass, straight-through heat exchanger can readily be detected by flow and dp measurement.
Evaluation of the events at Brunswick is still continuing.
Under conditions of an inoperable RHR system, heat rejection to the ultimate heat sink is typically through the main condenser or through the spent fuel pool coolers.
This latter path consists of the spent fuel pool pumps and heat exchanger with the reactor building closed cooling water system as an intermediate system which transfers the heat to the service water system via a single pass heat exchanger. These two means (i.e., main condenser or spent fuel pool) are not considered to be reliable long term system alignments under accident conditions.
This information is provided as a notification of a possibly significant matter that is still under review by the NRC staff. The events at Brunswick and San Onofre emphasize the need for licensees to initiate appropriate actions as requested by IEB 81-03 for any credible type of shell fish or other marine organisms; e.g., fresh water sponges, (not only asiatic clams and mussels).
In case the continuing NRC review finds that specific licensee actions would be appropriate, a supplement to IEB Bulletin 81-03 may be issued.
In the interim, we expect that licensees will review this information for applicability to their facilities.
No written response to this infnrmation is required.
If you need additional information regarding this matter, please contact the Director of the appro-priate NRC Regional Cffice.
Attachment:
Recently issued IE Information Notices.
O S
,-..y m
.h e
s Attachment IN 81-21 July 21, 1981 RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued to Notice No.
Issued 81-20 Test Failures of Elec-7/13/81 All holders of a trical Penetration power reactor Assemblies OL or CP 81-19 Lcst Parts in Primary 7/6/81 All holders of a Coolant System power reactor OL or CP 81-18 Excessive Radiation 6/23/81 Specified licensees Exposures to the Fingers holding Byproduct of Three Individuals licenses Incurred During Cleaning and Wipe Testing of Radioactive Sealed Sources at a Sealed-Source Manufacturing Facility 81-16 Control Rod Drive 4/23/81 All holders of a BWR System Malfunctions power reactor OL or CP 81-15 Degradation of Auto-4/22/81 All holders of a matic ECCS Actuation power reactor Capability by Isolation OL or CP of Instrument Lines 81-14 Potential Overstress of 4/17/81 All holders of a power Shafts on Fisher Series reactor OL 9200 Butterfly Valves with Expandable T Rings 81-13 Jammed Source Rack in 4/14/81 Specified Irradiator a Gamma Irradiator Licensees 81-12 Guidance on Order 3/31/81 All holders of a Issued January 9, 1981 power reactor Regarding Automatic OL or CP Control Rod Insertion on Low Control Air Pressure 81-11 Alternate Rod Insertion 3/30/81 All holders of a for BWR Scram Represents BWR power reactor a Potential Path for OL or CP Loss of Primary Coolant 81-10 Inadvertant Containment 3/25/81 All holders of a Spray Due to Personnel power reactor Error OL or CP p
y
-3 v
--.u
-w
,m m
e
-9