ML19262C037
| ML19262C037 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 01/17/1980 |
| From: | Counsil W CONNECTICUT YANKEE ATOMIC POWER CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0578, RTR-NUREG-578 NUDOCS 8001250526 | |
| Download: ML19262C037 (6) | |
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January 17, 1980 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)
H. R. Denton letter to W. G. Counsil dated January 2,1980.
(2)
W. G. Counsil letter to D. G. Eisenhut dated October 18, 1979.
(3)
W. G. Counsil letter to H. R. Denton dated November 21, 1979.
(4)
W. G. Counsil letter to J. Hendrie dated November 30, 1979.
(5)
W. G. Counsil letter to H. R. Denton dated December 7, 1979.
(6)
W. G. Counsil letter to H. R. Denton dated December 7,1979.
(7)
W. G. Counsil letter to H. R. Denton dated December 10, 1979.
(8)
W. G. Counsil letter to H. R. Denton dated December 12, 1979.
(9)
W. G. Counsil letter to H. R. Denton dated December 13, 1979.
(10)
W, G. Counsil letter to H. R. Denton dated December 14, 1979.
(11)
W. G. Counsil letter to H. R. Denton dated December 18, 1979.
(12) NUREG-0578, TMI-2 Lessons-Learned Task Force Status Report and Short-Term Recommendations.
(13)
D. G. Eisenhut letter to All Operating Nuclear Power Plants, dated September 13, 1979.
(14)
H. R. Denton letter to All Operating Nuclear Power Plants, dated October 30, 1979.
(15)
W. G. Counsil letter to H. R. Denton dated December 31, 1979.
(16)
B. H. Grier letter to W. G. Counsil dated June 25, 1979, transmitting I&E Bulletin No. 79-13.
Centlemen:
Haddam Neck Plant Containment Isolation In Reference (1), the Commission issued a Show-Cause Order to Connecticut Yankee Atomic Power Company (CYAPCO) regarding hnplementation of the Short-Term Lessons-Learned requirements at the Haddam Neck Plant. Reference (1) indicated that, based upon a review of References (2) through (11), the NRC Staff concluded that CYAPCO did not intend to implement some of the Category A require-ments until after January 31, 1980.
The Commission had determined that Lnplementation of all Category A requirements by January 31, 1980 is necessary to provide continued assurance of public health and safety, unless necessary equipment is unavailable.
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S The Show-Cause Order requires that CYAPCO implement, by January 31, 1980, the Category A requirements of Reference (12), as supplemented by References (13) and (14), or show cause why CYAPC0 should not.
Reference (1) further requested that CYAPC0 submit a description of the methods used to implement the Category A requirements of Reference (12) already completed. Accordingly, the following response ic provided.
CYAPC0 had previously submitted a c.omprehensive description of the implementation details of the Short-Term Lessons-Learned requirements via Reference (15),
thereby fulfilling this Refercuce (1) request. However, with respect to the Show-Cause Order, CYAPC0 notes that as verbally acknowledged by the Staf f, only one Short-Term Lesson-Learned requirement remains partially unresolved, that being the reset logic portion of Item 2.1.4, Containment Isolation.
There has been a series of verbal communications between the NRC Staff and CYAPCO during the past several weeks regarding interpretation of the Staff requirements.
It is essential at this juncture to delineate the implementation status of each of the documented Staff requirements:
Clarification (1)
Provide diverse containment isolation signals that satisfy safety-grade requirements.
Response
The presence of either high containment pressure signal or a safety injection signal result in a containment isolation signal. The requirement for diversity has been fulfilled.
Clarification (2)
Identify essential and non-easential systems and provide results to NRC.
Response
The identification of essential and non-essential systems was provided to the F.,C via Reference (15).
Clarification (3)
Non-essential systems should be automatically isolated by containment isolation signals.
Response
Non-essential systems are automatically isolated by containment isolation signals.
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Clarification (4)
Resetting of containment isolation signals shall not result in the automatic loss of containment isolation.
Response
CYAPC0 is currently haplementing a modification which, when completed, ensures that resetting of containment isolation signals will not result in the automatic loss of containment isolation. As explained in Reference (9), prior to a December 3,1979 telephone discussion with the Staff, CYAPCO's interpretation of this clarification was such that compliance could be achieved by explicit procedural guidance.
Having been verbally informed to the contrary, efforts are in progress to comply with this requirement on an expedited basis. To update the information provided in Reference (9), a total of nine valves were previously in conformance with this requirement. A total of 14 hand-switches located on the main control board require modification.
The modification involves the procurement and installation of four control relays which will be used to latch and unlatch safety signals as part of the reset logic. These four relays have been ordered from Westinghouse Electric Corporation.
Based upon information from the equipment vendor, receipt of these components is estimated to be February 11, 1980. CYAPCO is committed to complete implementa-tion of the modifications associated with the 14 hand-switches within 30 days of receipt of the necessary control relays.
Every effort is being made to expedite delivery of this order.
As can be deduced from the above discussion, CYAPC0 will be in compliance with all the documented Staff requirements and clarifications of Item 2.1.4 by March 12, 1980. The remaining undocumented issue concerns the reset features associated with 16 valves which are reset f rom five Pilot Solenoid Valves (PSV) located in the Primary Auxiliary Building (PAB) and the Main Steam Valve Building (MSVB). According to Staff representatives who participated in the December 3,1979 telephone discussion, the 16 FSV-controlled valves are un-acceptable because more than one valve can be reset by one deliberate operator action.
It is apparently postulated that grouped resetting may result in unnecessary unisolation of certain systems, although no specific accident scenarios have been identified. Although CYAPC0 recognizes and acknowledges the desirability of improving this configuration, it is noted that resolution of the Commission-issued Show-Cause Order revolves around undocumented and dynamic criteria. CYAPCO's displeasure regarding receipt of Reference (1) is reinforced by the fact that it fails to recognize the significance of this particular point relative to the primary objectives of Item 2.1.4, nor the timing of when this requirement was verbally imposed relative to the issuance of all the short-term requirements.
Furthermore, it was not until the issuance of Reference (1) that CYAPCO was informed of the results of the Staff's evaluation of the technical arguments presented in Reference (9).
Despite the completeness with which the above information justifies continued, safe operation of the Haddam Neck Plant beyor.d January 31,1980, CYAPC0 has pursued other avenues to resolve the matter. To summarize the configuration regarding 1810 165
. containment isolation, a total of 39 valves, as detailed in Reference (9),
respond to a containment isolation signal. A total of nine (9) are in full conformance. A total of 14 hand-switches located on the main control board are being modified to render the associated valves in full conformance.
A total of 16 isolation valves have their reset capability contained in the five PSV groups.
Justification for deferral of resolution past January 31, 1980 was provided, in CYAPCO's judgment, in Reference (9).
The Reference (1) provision authorizing delays of limited duration on the basis of equipment unavailability could rightfully be extended to accommodate the circumstances at the IIaddam Neck Plant.
Nonetheless, CYAPC0 has endeavored to be responsive to this point by designing a modification which would result in individuel valve reset capability.
The modification consists of installation of Individual control air tubing on each isolation valve with a new PSV in each valve's control air system. The new PSV's would be located in these new air supply lines in the same general area of the plant as the original PSV's for that group.
This modification would require minimum operator retraining to affect reset of a containment isolation signal.
It is emphasized that this modification retains the feature that upon reset of a containment isolation signal, actual valve position is unaffected.
The replacement PSV's are not currently qualified to necessary levels and are not a stocked item.
These replacement components have been ordered from ASCo.
Based upon information from the equipment vendor, receipt of these PSV's is estimated to be approximately May 15, 1980.
This date is based upon lead times of 12 - 20 weeks which are required by the equipment vendor. Alternate sources have been investigated and more expedient delivery dates have not been identified.
Considering the proximity of 30 days following scht duled receipt of the necessary equipment, even assuming optimistic delivery dates, to the scheduled start of the 1980 refueling outage, it is CYAPCO's position that ultimate resolution should not be required until the end of the refueling outage. The outage is currently scheduled to begin on May 3,1980.
The likelihood of achieving this date, as opposed to a deferral of the start of the outage, is supported by the following statistics. As of this writing, there are approximately 99 Eff ective Full Power Days (EFPD) remaining in the cycle. This includes an approximate twelve-day " coast" interval, involving rated thermal capacity at essentially zero boron concentration and a slightly decreasing electric capacity during this coast period. The capacity factor during the current cycle has been approximately 93.9%.
This has been achieved despite the forced loss of approximately ten EFPD's to fulfill the requirements of Reference (16).
The resultant inspections, which served to merely verify the adequacy of the existing configuration, were per-formed at a cost of five million dollars to Northeast Utilities' customers and stockholders, considering exclusively replacement power costs.
Thus, it would be reasonable to assume that the outage will not be significantly, if at all, delayed beyond May 3,1980.
It is also possible that the outage will commence sooner than currently anticipated.
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. Although detailed estimates are not currently availabic, the man-rem expenditures associated with the modification also support deferral until the refueling outage.
The appropriateness of deferring resolution until the refueling outage is also demonstrated to be prudent by recent verbal communications with the Staff indicating some reservations that individual valve reset capability available only locally would not be considered fully responsive to Staf f requirements.
As an argument supportive of deferring resolution, CYAPC0 verbally advised the Staft that as documented in Reference (15), the areas in the PAB and MSVB in the vicinity of the PSV's would not be accessible to plant operators assuming a TID-14844 source term.
Thus, the modification previously described would not substantially improve the reset capability of these valves, and is supportive of the position described in Reference (9), which concludes that an integrated assessment and resultant modification is the appropriate course of action.
Should the Staff require a commitment from CYAPCO that equipment be installed no later than 30 days following receipt of the last component to justify plant operation beyond January 31, 1980, please be advised that this letter provides that commitment.
Should the Staff determine that the design proposed above does not fulfill one or more of the undocumented Staff requirements, please recognize that designing another modification and procuring additional equipment would be an addition to that already discussed.
Thus, any modification to the PSV's could be completed no earlier than on the timetable discussed above.
Therefore, it is CYAPCO's position that plant operation beyond January 31, 1980 should be authorized even if the above circumstance is realized.
It is reiterated that docketing the basis for a Show-Cause Order and providing a focal point for verbal communications would substantively facilitate resolution.
In summary, this response is being docketed in a timely fashion as required by Reference (1) and by the provisions of 10CFR Part 2.
Considering all the Short-Term Lessons-Learned requirements, only the reset logic portion of Item 2.1.4 cannot be totally resolved by January 31, 1980.
Equipment delivery for the design proposed within is scheduled to be received approximately May 15, 1980.
The information provided above justifies deferral of modification of the PSV's until the outage. This would result in sufficient time for our respective Staffs to arrive at a mutually acceptable position.
In CYAPCO's judgment, this position would give due consideration to the concerns detailed in Reference (9).
In the interim, the Haddam Neck Plant can continue to operate safely, in compliance with the docketed Short-Term Lessons-Learned requirements.
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Should you not find the above information adequate to justify operation of the
!!addam Neck Plant beyond January 31, 1980, please advise promptly and the appropriate action will be taken to assure that the facility will not be shutdown without adequate justification.
Very truly yours, CONNECTICUT YANKEE AIDMIC POWER COMPANY T
W.'G. Counsil Vice President
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