ML20247R130
| ML20247R130 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 05/30/1989 |
| From: | Mroczka E CONNECTICUT YANKEE ATOMIC POWER CO., NORTHEAST UTILITIES |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20247R134 | List: |
| References | |
| A07433, A7433, TAC-61329, NUDOCS 8906070139 | |
| Download: ML20247R130 (9) | |
Text
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O General Offices e Selden Street, Berlin, Connecticut 1
l'iTZr.7lE"cL~
P.o. eox 270 N((",,7,7$.,,,
HARTFORD, CONNECTICUT 06141-0270 d
(203) 665-5000
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om t.u.mie nwaov cow-May 30, 1989 Docket No. 50-213 A07433 Re:
10CFR50.90 U.S. Nuclear Regulatory Commission Attention: Document Control Desk
. Washington, DC 20555 Gentlemen:
i Haddam Neck Plant Supplement to License Amendment Request Response to Reouest for Additional Information (TAC No. 61329)
In a letter dated April 25,1986,II) Connecticut Yankee Atomic Power Company j
(CYAPC0) submitted to the NRC Staff a proposed amendment to facility operating l
license, DPR-61, for the Haddam Neck Plant. The proposed changes would add a l
new technical specification section on Reactor Coolant System Leakage Detec-tion Systems to address one of the provisions established in the NRC Staff's NUREG-082
" Integrated Plant Safety Assessment, Systematic Evaluation
- Program,"g) for the Haddam Neck Plant.
ii' In a letter dated August 9, 1988,(3) the NRC Staff requested additional information to support their review of the proposed changes to the technical specifications.
CYAPC0 is hereby providing the requested information as
! to this letter.
The NRC Staff's Question 4 requested that the technical specification pages from the April 25, 1986 license amendment request be revised to be consistent a
with the Westinghouse Standard Technical Specification (H STS) format.
Accordingly, CYAPC0 is providing as Attachment 2 to this letter, revised technical specification pages in H STS format.
These revised pages are being forwarded as a supplement to the April 25, 1986 10CFR50.90 submittal.
l (1)
J.
F. Opeka letter to C.
I.
Grimes, " Proposed Revision to Technical Specifications - Leakage Detection Systems," dated April 25, 1986.
(2) NUREG-0826, " Integrated Plant Safety Assessment, Systematic Evaluation Program, Haddam Neck Plant, Final Report," dated June 1983.
(3)
A. B. Wang letter to E. J. Mroczka, " Request for Additional Information i
Regarding Proposed Revision to Technical Specifications for Leakage Detection System - Haddam Neck Plant (TAC #61329)," dated August 9,1988.
I 8906070139 epo33o
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DR ADOCK 05000213 p
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U.S. Nuclear Regulatory Commission A07433/Page 2 May 30, 1989 However, there are some changes from the original submittal that are outlined below.
Description of Technical Specifications o
Section 3.3.6.1 (Pages 3-4s, 3-4t) - RCS Leakage Detection Systems these limiting conditions for operation (LCO) and surveillance requirements (SR) replace Technical Specification Section 3.24 -(page 3-47) in the April 25, 1986 cubmittal; these specifications address l
systems for detecting leakage from the RCS.
o Table 4.2-1 (Pages 4-2b, 4-2c) - Minimum Frequencies for Testing, Cali-brating and/or Checking Instrumentation Channels these revised pages simply replace their counterparts in the-April _25, 1986 submittal.
o flaigi (Pages 3-4u, 3-4v, 3-4w, 3-4x) these pages are a supplement to the April 25, 1986 submittal, providing the bases for the RCS leakage detection technical specifi-cations in STS format; all of these pages are provided since the' pages were renumbered.
Differences from the April 25. 1986 Proposal There are some differences between the proposed technical specification in to this letter and the changes proposed in the April 25, 1986 submittal.
These differences are as follows:
o Section 3.3.6.1 - This revised technical specification does not include an operability requirement for the containment incore instrument sump.
level monitoring system, originally part of the April 25, 1986 package.
That original package proposed that either the containment incore sump or the containment main sump level monitoring system be OPERABLE.
The incore instrument sump level monitoring was deleted from the RCS leakage detection specifications since this system can only detect a leak in the j
" bottom mounted instrumentation" area of the reactor vessel.
The ACTION statement "c." allows the containment main sump level monitoring system to be inoperable for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> prior to commencement of a reactor shutdown.
In addition, the ACTION statement "d." requires CYAPC0 to take and analyze grab samples of the containment atmosphere at least once per four hours when both the containment Atmosphere Radioactivity Gaseous Radioactivity Monitoring System and Containment Sump Monitoring System are inoperable.
This will ensure timely identification of leaks in the 1 gpm range.
U.S. Nuclear Regulatory Commission A07433/Page 3 May 30, 1989 o
Table 4.2 This table retains the same number designation but has a few revisions.
Item 17, Volume Control. Tank Level, has been replaced with a footnote that references Specification 3.3.6.1 as providing the necessary surveillance requirements.
Existing Item 19 of Table 4.2-1 will ensure continued proper surveillance frequency on monitor operabil-ity.
The surveillance requirements are being clarified to indicate that the channel check will be done on a shift basis and that a functional test will be done on a monthly basis.
This is consistent with standard practice on the radiation monitors and is consistent with the W STS.
Items 18, 21, and 26 were replaced with footnotes stating that these instruments were now included in Table 3.23-2 as Items 1, 5, and 10.
In addition, a footnote that referenced the need to evaluate instrument operability following any seismic event greater than one half the safe shutdown earthquake (SSE) has been moved to Section 3.3.6.1 since the instruments to which it applied have been removed from the table (i.e.
Items 17, 21, and 30).
Significant Hazards Consideration In accordance with 10CFR50.92, CYAPC0 has reviewed the attached proposed change and has concluded that it does not involve a significant hazards consideration.
This represents a supplement to our previous significant hazards consideration.
The basis for this conclusion is that the three criteria of 10CFR50.92(c) are not compromised.
The proposed change does not involve a significant hazards consideration because the change would not:
1.
Involve a significant increase in the probability or consequences of an accident previous 1v evaluated.
The leakage detection system (LDS) is not credited directly in any design e
basis accident.
Therefore changes in operational and surveillance requirements on the LDS would not negatively impact the probability or consequences of any accidents that are part of the design basis.
However, these changes actually represent increased requirements since these are new technical specifications, and therefore, would have a positive impact on plant safety.
These new specifications will help assure the availability of the LDS.
Therefore, these changes would reduce the probability of a small leak progressing into a larger loss of RC5 inventory since the availability of the LDS will assure detection of small leaks (greater than 1.0 gpm) before they progress to larger leaks and a possible LOCA.
2.
Create the possibility of a new or different kind of accident from any previous 1v evaluated.
These are additional technical specification requirements which assure the operability of the LDS.
There are no failure modes associated with these changes.
Thus, the response of the plant is not modified to the point where it can be considered a new
(
accident.
These changes do increase the probability of a controlled shutdown since a reactor shutdown is required if the volume control tank (VCT) or the r
U.S. Nuclear Regulatory Commission A07433/Page 4 May 30, 1989 J
containment main sump level monitoring systems are inoperable.
- However, a controlled shutdown is within the design basis of the plant.
There-fore, the possibility for an accident or malfunction of a different type than any evaluated previously is not created.
3.
Involve a significant reduction in a maroin of safety.
These proposed changes actually have a positive impact on the margin of safety because they will increase the potential for detecting small leaks prior to their becoming large leaks.
These proposed changes would assure that the LDS is available and performing its intended function.
Moreover, the Commission has provided guidance concerning the application of standards in 10CFR50.92 by providing certain examples- (March 6,
- 1986, 51FR7751) of amendments that are considered not likely to involve a signifi-cant hazards consideration. The proposed changes herein would most closely be enveloped by Example (ii), "A change that constitutes an additional limita-1 tion, restriction, or control not presently included in the technical specifi-
- cations, e.g.,
a more stringent surveillance requirement."
These proposed changes impose additional operability requirements with corresponding action j
statements and surveillance requirements.
They represent an improvement in overall plant safety.
Based upon the information contained in this submittal and the environmental assessment for the Haddam Neck Plant, there are no significant radiological or nonradiological impacts associated with the proposed license amendment, and it will not have a significant effect on the quality of the human environment.
l The Haddam Neck Plant Nuclear Review Board has reviewed and approved the attached proposed changes and concurs with the above determinations.
CYAPC0 does not have a pressing need for this license amendment.
Therefore, no specific issuance date has been requested.
Nonetheless, CYAPC0 does i
request that this amendment be specified to be effective 30 days after issu-ance to allow adequate time for implementation.
I In accordance with 10CFR50.91(b), CYAPC0 is providing the State of Connecticut I
with a copy of this amendment request supplement.
We trust that you will find this information satisfactory to address this issue.
Very truly yours, CONNECTICUT YANKEE ATOMIC POWER COMPANY M
CW E. f? Mrotzka /
Senior Vice Pre /
sident
~.
L' U.S. Nuclear Regulatory Commission A07433/Page 5 May 30, 1989
.. T. Russell, Region I Administrator W
cc:
A. B. Wang, NRC Project Manager, Haddam Neck Plant J. T. Shedlosky, Senior Resident Inspector, Haddam Neck Plant Mr. Kevin McCarthy Director, Radiation Control Unit Department of Environmental Protection Hartford, Connecticut 06116 STATE OF CONNECTICUT)
) ss. Berlin COUNTY OF HARTFORD )
Then personally appeared before me, E. J. Mroczka, who being duly sworn, did state that he is Senior Vice President of Connecticut Yankee Atomic Power Company, a Licensee herein, that he is authorized to _ execute' and. file the foregoing information in the name and 'on behalf of the Licensee herein, and that the statements contained in said information are true and correct to the best of his knowledge and belief.
sd S h kh Notary ~ Pu c
MyCommiss!on Exp!res March 31,1993 I
t Docket No. 50-213 A07433 Haddam Neck P1 ant Response to Request for Additional Information Regarding Proposed Revision to Technical Specifications for. Leakage Detection Systems l
l l
l May 1989 l
- 1...
y
. Attachment 1 A07433\\Page 1 Haddam Neck Plant Additional Information Leakaae Detection Systems Ouestion 1 The IPSAR stated the leakage detection systems could meet a sensitivity of I gpm in I hour.
Your current submittal states the leakage detection systems have a sensitivity of I gpm in 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
Please provide the sensitivity of the four leakage detection systems (Airborne Gaseous Radioactivity Monitoring a
System, Volume Control Tank (VCT) Level Monitoring, the Containment Instrument Sump and the Containment Main Sump Level Monitoring Systems) and analysis or data to demonstrate that sensitivity.
CYAPC0 Response:
The sensitivities of the three leakage detection systems are provided below.
The Containment Instrument Sump is no longer being proposed as an option, and therefore its sensitivity is not provided.
Airborne Gaseous Radioactivity Monitorina System The Airborne Gaseous Radioactivity Monitoring System (RMS-12) will see a slight increase in activity due to a 1 gpm primary leak to containment.
Assumptions used are:
6 3
1)
CTMT volume = 2.232 x 10 Ft 2)
RCS Noble gas activity - 1 yci/gm Xe-133 3)
Monitor response is I hour after leak initiation The normal reading on the monitor is 3000 counts / minute (cpm).
From the RMS-12 calibration chart, a 1 gpm leak rate would add 2000 cpm to the response, for a total of 5000 cpm.
On a logarithmic scale (which the instru-ment uses) a response of 5000 cpm is detectable, but near the limits of detection.
If reactor coolant system (RCS) activity is low, it will be difficult to detect a 1 gpm RCS leak in 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
If RCS activity is abnormal-ly high, then the monitor could be offscale already, rendering this approach to monitoring RCS leakage difficult.
However, these are rare situations.
The majority of the time, RCS activity is within a range that corresponds with the instrument sensitivity described above.
to detect a 1 gpm RCS leak in 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
Accordingly, the instrument is able Volume Control Tank (VCT) Level Monitorina System The overall accuracy of the VCT level indication was determined to be of span.
A calculation defining this value is on file with CYAPCO.
2.87%
change in the VCT inventory.of 2.87% of span in the VCT level indication A change In order to detect an RCS leak of I gpm in 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, we would need to be able to detect a change in RCS volume of 240 gallons (i.e., I gpm x 60 minutes / hour x 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />).
the VCT level indication, a 1 gpm RCS leak for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> can be detectedBased on th
. Attachment 1 A07433\\Page 2 The VCT level monitoring system is the system credited as the method of leakage detection at Haddam Neck.
While this system does not totally conform to the " leakage detection system" definition in Regulatory Guide 1.45, when used to determine inventory balances it represents the Haddam Neck Plant's most sensitive and reliable method of determining uncontrolled and unidenti-fied RCS leakage.
IPSAR Section 4.16.4 recognizes inventory balance methods as an acceptable alternative to " leakage detection systems."
One design feature of the VCT level monitoring system that contributes to its inherent sensitivity is that the volume of the VCT is approximately one half the size of the typical Westinghouse PWR VCT.
Instrumentation available to the opera-tor to monitor level changes include a strip chart recorder and a rate of level change alarm.
During steady state power operation, the operator performs an hourly surveil-lance using VCT level change to quantify the average RCS leak rate.
This is possible since the VCT level remains fairly constant (minus RCP leakage) during steady state operation.
Plant procedures are used in monitoring RCS leakage via VCT level changes, The procedure ensures that certain variables that could affect the surveillance are checked.
This process has been demon-strated to be sensitive enough to detect a 1 gpm RCS leak in 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
Containment Main Sump Level Monitorino System The overall accuracy of the Containment Main Sump Level Indication System was determined to be 4.24% of span.
A calculation defining this value is on file with CYAPCO.
A change of 4.24% of span in the Containment Main Sump level indication corresponds to an approximately 84.8 gallon change in the Containment Main Sump inventory.
In order to detect an RCS leak of I gpm for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, we would need to be able to detect a change in RCS volume of 240 gallons (i.e.,1 gpm x 60 minutes / hour x 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />).
Based on the accuracy of the Containment Main Sump indication, this instrument can detect a 1 gpm RCS leak in 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
Question 2:
Do the leakage detection systems have any annunciation alarms to indicate that there is a leak?
CYAPC0 Response:
There is alarm annunciation for these systems.
However, the setpoints are not specifically related to RCS leakage.
This would be difficult based on the possible variations in initial conditions for the subject systems.
There is one alarm for Airborne Gaseous Radioactivity located on the main control board (MCB).
The alarm setpoint for the monitor varies. The Contain-ment Main Sump Level Indication System has two alarms at 15% and 75% of span.
The VCT level indication system has three alarm setpoints:
Hi - 90%, Lo -
26%, and Lo-Lo - 10%. All of these annunciate on the MCB.
L
.. Attachment 1 A07433\\Page 3 Ouestion 3:
Why was the Containment Atmosphere Gaseous Radioactivity Monitoring System excluded from the post-greater than one half SSE surveillance requirement?
CYAPC0 Response:
As part of the review of SEP Topic V-5,I4) the NRC Staff recommended that at least one reliable method of leakage detection be either qualified to a safe-shutdown-earthquake (SSE) seismic event or have procedures in place that specify actions to be taken for a seismic event to accommodate any resulting failures.. As a result of this NRC Staff recommendation, CYAPC0 chose the Volume Control Tank and Containment Main Sump Level Monitoring Systems as the reliable leakage detection method.
Surveillance Specifications 3.3.6.1 b and c require implementation of certain procedures following a seismic event greater than 1/2 SSE and therefore these systems do not have to be qualified.
Since the Containment Atmosphere Gaseous Radioactivity Monitoring System is only a backup, it does not have this surveillance requirement.
Question 4:
Can the format be more consistent with the STS?
CYAPC0 Response: to this letter consists of appropriate technical specification pages in STS format.
I (4) NUREG-0826, " Integrated Plant Safety Assessment Systematic Evaluation Program," dated June 1983.
_ _ _ _