05000213/LER-1997-001, :on 970114,river Temperature Below UFSAR Analyzed Condition Occurred.Caused by Design Basis Calculations Were Not Updated in a Timely Manner.Ufsar & Design Basis Calculations Will Be Revised
| ML20138M244 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 02/11/1997 |
| From: | Laplatney J, Sabean D CONNECTICUT YANKEE ATOMIC POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| B16245, LER-97-001, LER-97-1, NUDOCS 9702250307 | |
| Download: ML20138M244 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition |
| 2131997001R00 - NRC Website | |
text
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S CONNECTICUT YANKEE ATO MIC POWER COMPANY HADDAM NECK PLANT 362 INJUN HOLLOW ROAD e EAST HAMPTON, CT 06424-3099 February 31, 1997 Re: 10CFR50.73 (a) (2 ) (ii)
B16245 U.
S. Nuclear Regulatory Cornmission Document Control Desk Washington, D. C.
20555
Reference:
Facility Operating License No. DPR-61 Docket No. 50-213 Reportable Occurrence LER a0-213/97-001-00 This letter forwards the Licensee Event Report 97-001-00, required to be submitted, pursuant to the requirements of the Haddam Neck Plant's Technical Specifications.
Very truly yours,
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La latn Unit Director i
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Attachment:
LER 50-213/97-001-00 cc:
Mr. H. J. Miller Regional Administrator, Region I 475 Allendale Road King of Prussia, PA 19406
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c4 Mr. William J. Raymond gh
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Sr. Resident Inspector Haddam Neck l
i 250052 9702250307 970211 PDR ADOCK 05000213 i
S PDR 1028-J REV 2 01
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NRC FORM 366 U.S. NUCLEAR RE2ULATORY CohmalSSION APPROVED BY OMB NO. 31504104 g
M61
- - EXPIRES 04/30/98 ESTIMATED BURDEN PER RESPONSE TO CORAPLY WITH Tits MANDATORY WFORMATION COufCTION REQUEST: 60.0 HRS. REPORTED LESSONS MANNED ARE LICENSEE EVENT REPORT (LER)
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FORWARD C00AWITS REGAR0586 BURDEN ESTRIATE TO M WFORidATlW6 AND RECORDS RIANAGElmli tRANCH IT-6 F33L U.5. NUCLEAR REGULATORY C00AN8810N, i
(See reverse for required number of Wasem0 TON DC 20ser>a000 MD TO THE PAPERWORK REDUCTION PROJECT MSG j
digits / characters for each block) 0% OmCE Of MANAGEMMT AND BUDGH, WASHMGTW, DC 20sn encarryuna m nomeT muumeR m rama m Haddam Neck 05000 - 213 1 OF 4 l
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River Teitperature Below UFSAR AnalyzedJCondition j
EVENT DATE (5)
LER NUhMIER (6)
REPORT DATE (7)
OTHER FACILITIES INVOLVED (8) t Acu.rrY NAME DOCKET NUMeER SE AL RE j
MONTH DAY YEAR YEAR MONTH DAY YEAR w
p w
05000 F ActuTv NAME DOCKET NUMeER 01 14 97 97 001 00 02 11 97 05000
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OPERATING THl8 REPORT IS SUBhMTTED PURSUANT TO THE REQUIREMENTS OF 10 CFR 4: (Check one or more) (11) i MODE (9)
N 20.2201(b) 20.2203(aH2)(v) 50.73(a)(2)(i) 50.73(aH2Hvui) l 20.2203(eH1) 202203(aH3Hi)
X 50.73(aH2HM 50.73(aH2H4 POWER LEVEL (10) 000 20.2203(aH2Ho 20.2203(a)(3)(u) 50.73(a)(2)(m) 73.71 l
20.22%e)(2)(u) 20.2203(a)(4) 50.73(a)(2Hiv)
OTHER l
20.2203(aH2Hin) 50.36(c)(1) 50.73(a)(2)(v)
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20.2203(a)(2Hiv) 50.36(c)(2) 50.73(a)(2Hvid i
LICENSEE CONTACT FOR THIS LER (12)
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NAME TELEPHONE NUMeER pnotune Ares Cosel l
D. Sabean, Engineering Design (860) 267-2556 COneLETE ONE LINE FOR EACH COhrONENT FAILURE DESCRIBED IN THIS REPORT (13) i RE E
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CAUSE
SYSTEM COMPONENT MANUFACTURER
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CAUSE
SYSTEM COMPONENT MANUFACTURER g
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l SUPPLEIENTAL REPORT EXPECTED (14)
MONTH DAY YEAR EXPECTED YES SUBhSSSION NO (if yes, complete EXPECTED SUBMISSION DATE).
y DATE (15)
ABSTRACT (Umit to 1400 epaces, Le., approximately 16 eingle-spaced typewntten linee) (16) i On January 14, 1997, at approximately 1530 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.82165e-4 months <br />, with the plant in a j
defueled mode, a reportability evaluation determined that the plant had been in a condition outside of the analyzed service water supply temperature range.
Both the Haddam Neck Updated Final Safety Analysis i
(UFSAR) and the service water supply piping stress analysis reference 35 degrees F as the minimum service water supply temperature, however, historically, there have been times when the average supply (river water) i temperature was below 35 degrees F.
This condition was previously
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identified in February 1996 (LER 96-002-00).
Although actions were j
initiated to update the UFSAR, the changes were never made resulting in a recurrence of the same condition.
The cause was a program deficiency in
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that the design basis calculations were not updated in a timely manner.
j It was determined that there are no limiting effects associated with j
overcooling any components and that the lower supply temperature had no 4
effect on existing emergency core cooling calculations or on the structural j
integrity of the service water system.
Corrective action consists of revising the'UFSAR and the design basis calculations to reflect the normal 4
operating temperatures of the service water system. In addition there is a formal, ongoing effort to identify and correct UFSAR inaccuracies, j
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NRC FDRM 366A U.U. NUCLEAR RE4ULATORY COMMISSION i4se 1
UCENSEE EVENT REPORT (LER)
TEXT CdNTINUATION l
FACluTY NAME (1)
DOCKET LER NUWER (6)
PAGE (3) l i
MAR SEQUENTIAL REVISION NUMBER NUMBER Haddam Neck 05000 -
2 OF 4 213 97 - 001
- - 00
)
TEXT (11 more space is required, use additional copies of NRc Forrn 366A) (11) i
BACKGROUND INFORMATION
)
The service water system (EIIS Code: BI) provides cooling water to both the primary and secondary systems during normal at power operation and plant cooldowns.
It also provides cooling water to vital components during emergency conditions.
The plant's four service water pumps comprise two service water headers.
The north service water header includes the
'A' and
'B' service water pumps and the south service water header includes the
'C' and
'D' pumps.
Technical Specification 3.7.3 requires two service water headers to be operable in Modes 1,2,3, and 4.
The source of water for the service water system is the Connecticut River which is also the Haddam Neck Plant's ultimate heat sink.
The Haddam Neck plant is currently in a defueled condition and has notified the NRC of its decision to permanently cease power operation and has permanently removed fuel from the reactor vessel.
Therefore all reference to operation in Modes 1, 2,
3, and 4 is no longer applicable to the service water system.
In the defueled state service water provides cooling to the spent fuel pool heat exchangers, the emergency diesel generators and to a small number of secondary plant components.
i The system description for the service water system in the Updated Final Safety Analysis Report (UFSAR), section 9.2.1.2 states :
"The inlet I
I operating temperature extremes of the service water system are 90 degrees F maximum and 35 degrees F minimum...".
Technical Specification Limiting Condition for Operation 3.7.12 states : "The ultimate heat sink shall be OPERABLE with an average circulating water inlet temperature of less than or equal to 90 degrees F in Modes 1, 2,
3 and 4.."
No limitations are imposed for minimum water temperatures.
EVENT DESCRIPTION
On January 14, 1997, at approximately 1530 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.82165e-4 months <br />, with the plant in the defueled mode, a reportability evaluation determined that the plant had been in a condition outside of the analyzed service water supply temperature range.
Both the Haddam Neck Updated Final Safety Analysis Report (UFSAR) and the service water supply piping stress analysis reference 35 degrees F as the minimum service water supply temperature, however, historically, there have been tines when the average supply (river water) temperature was below 35 degrees F.
NRC FORM 308A 14061
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NRC rbsud SGSA U.E NUCLEAR REAULATORY C-en0N use LICENSEE EVENT REPORT (LER) l TEXT CONTINUATION FACRJTY NAhE (1)
DOCKE1 LER NURSER (6)
PAGE(3)
HAR SEGUENTIAL -
REVl810N Haddam Neck 05000 -
- - 3 OF 4 213 97 " 001 00 l
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j TEXT Uf more spece is reqwred, use add,toonal copies of NRC Form 366A) (17) i
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CAUSE OF THE EVENT
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j This condition was previously identified in February 1996 (LER 96-002-00) j i
when a review of the UFSAR and piping stress analysis identified a i
discrepancy between the documented minimum service water inlet operating i
temperature and actual winter operating conditions experienced at the Haddam Neck plant.
4 Although actions were initiated to update the UFSAR, the changes were never made resulting in a recurrence of the same condition.
The cause was a program deficiency in that the design basis calculations were not updated in a timely manner.
i
SAFETY ASSESSMENT
This event is reportable under 10CFR50.73(a)(2)(ii)(B) since it resulted in a condition that was outside the design basis of the plant.
i)
A qualitative evaluation was performed for lower service water (SW) f temperatures, conservatively assumed to be as low as 28 degrees F which
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is the freezing point of sea water.
It was concluded that there are no limiting effects associated with overcooling any components.
An evaluation was made of the effect of the lower SW supply temperature on the structural integrity of the SW piping, pipe supports, valves and i
equipment.
It was found that the material allowable values will not change appreciably as a result of lowering the temperature 7 degrees to 28 degrees F.
This temperature change will have an insignificant impact on the thermal stress levels of the piping system and support ~ loads since the change in the coefficient of expansion and the modulus of elasticity of the piping materials is insignificant.
SW flaw evaluations will not be affected significantly since the thermal piping loads will remain essentially the same.
In addition, flexible supports of the SW system allow for minor changes in piping displacement.
Since piping loads and displacements do not change significantly the resultant impact on nozzle loads is considered negligible.
The structural integrity of valve bodies, pumps, heat exchangers, strainers, etc. is bounded by the piping acceptability.
From these evaluations it was concluded that the system structural integrity is not degraded by operating at the lower temperature.
In accordance with normal design practices, all of the heat exchangers receiving cooling from the SW system were specified using maximum SW supply temperature with minimum temperature not being a critical design temperature.
Minimizing SW supply temperature will have the effeet of improving heat exchanger performance, mac sonu mean was
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NRC FORM SSSA U.S. NUCLEAR RE2ULATORY Cme 0N
^
14ss LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACRJTY NAhE (1)
DOCKET LER NUWR (6)
PAGE (3) l HAR SEQUENTIAL REVtBION 4
NUMBER NUMBER l
Haddam Neck 05000-4 OF 4 213 97 - 001 00 mmmer i
TEXT (11 rnote space a recturred, use additional copies of NRC Form 366A) (17)
L Based on the above evaluations, and the fact that the plant was in a defueled condition during the period of low river water temperatures, it was concluded that the safety significance of this event is low.
CORRECTIVE ACTION
j Corrective action consists of developing a new tracking system which is specifically designed to identify these types of commitments.
In l
addition, the remaining backlog of proposed changes to the UFSAR is being j
i screened to ensure there are no other similar issues.
The UFSAR and design basis calculations will be revised to reflect the normal operating temperatures of the service water system.
Also, there is a formal, ongoing effort to identify and correct UFSAR inaccuracies.
i i
ADDITIONAL INFORMATION
t
Commitments
The following are commitments made within this report.
All other statements are for information only:
316245-1 A new tracking system will be developed which is specifically designed to identify these types of
commitments
B16245-2 The remaining backlog of proposed changes to the UFSAR is being screened to ensure there are no other similar issues.
B16245-3 The UFSAR and design basis calculations will be revised to reflect the normal operating temperatures of the service water system.
PREVIOUS SIMILAR EVENTS
LER 96-002-00, " River Temperature Below UFSAR Analyzed Condition".
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