ML16301A153

ACRS Comments on Licensee Event Reports Pertaining to Control Room Habitability

ML16301A153
Person / Time
Issue date:	07/15/1987
From:	Kerr W Advisory Committee on Reactor Safeguards
To:	Stello V NRC/EDO
References
D870715
Download: ML16301A153 (2)

Text

D870715 Mr. Victor Stello, Jr.

Executive Director for Operations U.S. Nuclear Regulatory Commission Washington, D.C. 20555

SUBJECT:

ACRS COMMENTS ON LICENSEE EVENT REPORTS PERTAINING TO CONTROL ROOM HABITABILITY For a number of years, members of the Advisory Committee on Reactor Safeguards, supported by ACRS Fellows, have examined Licensee Event Reports (LERs) pertaining to air cleaning, ventilating, and monitoring systems at commercial nuclear power plants. Several of the more recent of these studies have concentrated on LERs specifically pertaining to control room habitability.

The latest of these studies, which covered the three-year period from 1984 through 1986, has revealed the following information:

1. On an annual basis, from 3% to 8% of all LERs pertained to systems related to control room habitability. For the three-year period, 7% of all LERs were in this category. This represented a total of over 500 LERs.

2. Of the LERs in this category, 61% were due to problems involving air monitors. Of these, 55% were due to problems with radiation monitors and 29% were due to problems with chlorine monitors.

Most of these events were reported as LERs because malfunctions of the monitoring equipment led to actuations of the control room emergency ventilation system. The large number of LERs in this category indicates a need to address attention to their origin and the need for corrective action. Such events almost certainly reflect a lack of reliability on the part of certain types of air monitoring equipment.

Several approaches may be useful in planning corrective action. Al-though malfunctions of chlorine monitors account for a significant percentage of the cited LERs, data for the past several years indicate essentially no problems with these types of monitors at certain nuclear power plants. It might be beneficial to determine whether such monitors are in use in these plants and, if so, what type they are and how they are maintained and operated. Such information could be useful in resolving some of the problems observed at other plants.

A second approach might be for the NRC Staff to consider encouraging all nuclear power plant licensees to adopt the provisions of the current Standard Technical Specifications which specify a time limit within which a defective air monitor would have to be repaired and placed back into service. Such a requirement would help make the management at all plants aware of the need to purchase and install reliable air monitoring equipment and to maintain it in proper working order.

Sincerely, William Kerr Chairman