ML19256F307
| ML19256F307 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 12/13/1979 |
| From: | Counsil W, Fee W CONNECTICUT YANKEE ATOMIC POWER CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| TASK-06-04, TASK-6-4, TASK-RR NUDOCS 7912180476 | |
| Download: ML19256F307 (7) | |
Text
.
CONNECTICUT YANKEE AT O M IC POWER COMPANY BERLIN. CONNECTICUT P
O. BOX 270 H ARTFORD. CONNECTICUT 06101 Tataewo=r 203-666-6911 Dec ember 13, 1979 Docket No. 50-213 Office of Nuclear Reactor Regulation Attn:
Mr. H. R. Denton, Director U. S. Nuclear Regulatory Commission Washington, D. C.
20555
References:
(1)
W. G. Counsil letter to D. G. Eisenhut, dated October 18, 1979.
(2)
W. G. Counsil letter to H. R. Denton dated November 21, 1979.
(3)
D. G. Eisenhut letter to All Operating Nuclear Power Plants, dated September 13, 1979.
(4)
H. R. Denton letter to All Operating Nuclear Power Plants, dated October 30, 1979.
Gentlemen:
Haddam Neck Plant Containment Isolation In References (1) and (2), Connecticut Yankee Atomic Power Company (CYAPCO) responded to References (3) and (4) by indicating that fulfillment of Require-ment 2.1.4, Containment Isolation, would be achieved by January 1,1980.
During a telephone conversation on December 3, the Staff initiated discussion on the topic of containment isolation, with particular emphasis on clarifica-tion Item (4) of Reference (4).
CYAPCO's previous commitment to comply with Item (4) was based upon CYAPCO's understanding that prevention of loss of containment isolation upon reset of a containment isolation signal could be accomplished by sperator action prior to reset.
It was also CYAPCO's understanding that ganged valves, where reset of more than one valve occurs with one deliberate operator action, represented an acceptable configuration.
During this December 3 conversation, the Staff advised that such was not the case under their interpretation. Although CYAPC0 continues to believe that the objectives of the Staff requirement would be fulfilled by the use of appropriate procedures and resultant operator ac tion, CYAPCO verbally advised that it is impossible to perform the hardware modifications necessary to comply with the Staff requirements by January 1,1980.
CYAPC0 agreed to document this fact, and elaborate on the scope of and complications associated with the modifications necessary to comply with Staff require-ments. With the exception of the items identified below, the requirements of Reference (4), including the requirement for diverse actuation signals, will be fulfilled by January 1,1980.
Accordingly, the following information is provided.
1608 352 7 912180+7%
/
. A total of 39 valves respond to a containment isolation signal at the Haddam Neck Plant.
The attached listing provides the following information for each valve:
(1) Valve nwmber (2) Valve title -- indicates af fected system (3) Valve location (4) Location of Post-CI Control As can be seen from this listing, a total of 19 valves can be controlled by hand-switches located on the main control board. According to the procedure which will be in effect by January 1, 1980, these are the hand-switches which would be positioned by the operator to the isolated state af ter receipt of a CI signal, but before reset of a CI signal.
In order to comply with the clari-fication verbally provided by the Staf f on December 3,1979, these switches would require redesign and replacement.
Additional relays, switches, and terminations would be required for each of the nineteen hand-switches. More than one design has been utilized, thereby eliminating the possibility of a generic fix to this concern.
The replacement hand-switch would be of the same size as the existing switch; therefore, adequate surface control board space is available.
The more complex circuitry associated with the replacement switch would require additional sub-surface board space, which is already at a premium.
Also as shown on the attached listing, a total of 16 valves are controlled from five Pilot Solenoid Valves (PSV) located in the Primary Auxiliary Building (PAB) and Main Steam Valve Building (MSVB).
The design of the remaining four valves is in conformance with the Staff requirements of Reference (4) as clarified on the attachment.
Pursuant to the December 3 telephone conversa-tion, the 16 PSV-controlled valves are unacceptable because more than one valve can be reset by one deliberate operator action.
It is noted that these valves are not repositioned upon reset of a CI signal, and could not be repositioned without operator action at a remote location. A fix for this situation would, as a minimum, require providing individual PSV for each valve in the gang.
CYAPCO's evaluation of the above-described configuration is that adequate procedural controls will be in effect by January 1,1980, to ensure that the objectives of Reference (4), Item 2.1.4 will be fulfilled.
Specifically,
in the event of an accident, containment integrity and isolation will be maintained unless the operating Staff consciously and deliberately wishes to unisolate a system or systems.
Furthermore, CYAPCO's assessment of the modifications required to upgrade the circuitry, in light of the existence of the Systematic Evaluation Program (SEP) and other recommendations of Task Forces and various review groups evaluating the TMI-2 accident, indicates that the appropriate time to complete these modificatior.s is in conjunction with the SEP.
The SEP topic most relevant to this NUREG item is Topic VI-4, Containment Isolation Systems. However, Topic VI-4 requires resolution of a broader spectrum of issues, including General Design Criteria 54 through 57.
An attempt to redesign at this stage, in view of Standard Review Plan 6.2.4, 1608 353 would raise questions regarding position indication, seismic criteria, valve closure times, redundancy, power supplies, and actuation signals.
Relocation of the controls of PSV valves to the control room would require additional control board space which is not readily available without compromising the human engineering aspect of the design.
CYAPCO considers it prudent to d ef er completion of this design effort until other SEP and TMI issues, which may require additional board space, are resolved, such that an integrated design with due co-sideration to the man-machine interface can be accompl#.shed. One such example is Regulatory Guide 1.97, Post-Accident Monitoring.
It is no t inferred that this concern should not be addressed before the end of the SEP, but only that related SEP/TMI topics be resolved before modifications commence.
The Staff-published status for Topic VI-4 categorizes it as a high priority item, and calls for initiation of the review effort for the Ifaddam Neck Plant early in 1980. The ef ficiency of integrating SEP and TMI-related evaluations and the resulting modifications warrants def crral in this case.
We trust you find the above information suf ficient to clarify our position.
Very truly yours, CONNECTICUT YANKEE ATOMIC POWER COMPANY W. G. Rounsil Vice President e
By:
W. F. Fee Vice President.
At tachment 1608 354
DOCKET NO. 50-213 IIADDAM NECK PLANT AUTOMATIC CONTAIMIENT ISOLATION VALVES DECDIBER, 1979 1608
.555
Haddam Neck Plant Autcmatic Containment Isolation Valves Location of Post Valve Number Valve Title Valve Location CI Control LD-A0V-202 Letdown Orifice PAB Containment Trench Switch on MCB LD-A0V-203 Letdown Orifice PAB Containment Trench Switch on MCB LD-A0V-203 Letdown Orifice PAB Containment Trench Switch on MCB SS-TV-950 Drain Header Sample Trip PAB Trench Under Switch on MCB Sample Room SS-TV-955 Press. Steam Sample Trip PAB Trench Under Switch on MCB Sample Room SS-TV-960 Press. Liquid Sample Trip PAB Trench Under Switch on MCB Sample Room SS-TV-965 Loop 1 Hot Leg Sample Trip PAB Trench Under Switch on MCB Sample Room DH-A0V-554 Relief Tank Drain PAB Trench Under Switch on MCB Sample Room WG-A0V-558 Relief Tank Vent PAB Trench Under Switch on MCB Sample Room CC-FCV-608 RCP-Thermal Barrier Return PAB Blowdown Tank Room Switch on MCB CC-FCV-611 Drain Cooler CC Outlet PAB Blowdown Tank Room Switch on MCB CH-TV-334 Seal Water Return Trip PAB Mezzanine Switch on MCB DH-TV-1841 Drain Header PAB Lower Level Switch on MCB MOV-200 Letdown Isolation Valve Containment Swtich on MCB MOV-331 RCP Seal Bypass Containment Switch on MCB MOV-311 RCP Seal Water Return Containment Swtich on MCB MOV-312 RCP Seal Water Return Containment Switch on MCB MOV-313 RCP Seal Water Return Containment Switch on MCB MOV-314 RCP Seal Water Return Containment Switch on MCB DH-TV-1842 Valve Stem Leakoff Header PAB Trench Under Pilot Valve 20-TVI Sample Room in PAB 1608; 356
Location of Post Valve Number Valve Title Valve Location CI Control DH-TV-1843 Vapor Seal Head Tank Drain PAB Trench Under Pilot Valve 20-TVI Sample Room in PAB DH-TV-184' Drain Header PAB Lower Level Pilot Valve 20-TVI in PAB SG-TV-1312-1 S.G. Blowdown PAB Blowdown Tank Room Pilot Valve 20-TV2 in PAB SG-TV-1312-2 S.G. Blowdown PAB Blowdown Tank Room Pilot Valve 20-TV2 in PAB SG-TV-1312-3 S.G. Blowdown PAB Blowdown Tank Room Pilot Valve 20-TV2 in PAB SG-TV-1312-4 S.G. Blowdown PAB Blowdown Tank Room Pilot Valve 20-TV2 in PAB CC-TV-1831 NST Cooling Water Return PAB Blowdown Tank Room Pilot Valve 20-TV3 in PAB CV-TV-1411 RCP Bearing Cooling PAB Upper Level Pilot Valve 20-TV3 Water Return in PAB MS-TV-1212 Main Steam Line Drain Main Steam Penetration Pilot Valve 20-TV4 to Blowdown Tank Enclosure in MSPE MS-TV-1213 Main Steam Line Drain Main Steam Penetration Pilot Valve 20-TV4 to Condenser Enclosure in MSPE WD-TV-1846 Containment Sump Discharge PAB Trench Under Pilot Valve 20-TV5 Sample Room in PAB DH-TV-1844 Relief Tank Drain PAB Trench Under Pilot Valve 20-TV5 Sample Room in PAB WG-TV-1845 Relief Tank Drain PAB Trench Under Pilot Valve 20-TV5 Sample Room in PAB LM-TV-1811B Containment Leak Monitoring PAB Blowdown Tank Room Pilot Valve 20-TV5 in PAB RM-TV-1848 Air Activity Inlet PAB Pipe Trench Pilot Valve 20-TV5 in PAB LM-TV-1811 Containment Leak Monitoring PAB Blowdown Tank Room Manual Relatch on Valve LM-TV-1812 Containment Leak Monitoring PAB Blowdown Tank Room Manual Relatch on Valve 1608 357
.' Location of Post Valve Number Valve Title Valve Location CI Control WC-HICV-1840 Containment Sump Discharge PAB Trench Under Automatically opens Sample Room on sump pump start.
Sump pump is manual.
Line further isolated by Valve WD-TV-1846 above.
SOL-12-1 Air Activity Inlet PAB Upper Level Automatically opens when air sampling puno starts. This pump is manual.
Line further isolated by Valve RM-TV-1848 above.
1608 358